Judgment of 20 April 2010 | INTERNATIONAL COURT OF JUSTICE

COUR INTERNATIONALE DE JUSTICE

RECUEIL DES A|TS,
AVIS CONSULTATIFS ET ORDONNANCES

AFFAIRE RELATIVE A v DES USINES DE PÂTE
v PAPIER SUR LE FLEUVE URUGUAY

(ARGENTINE c. URUGUAY)

ARR|T DU 20 AVRIL 2010

2010

INTERNATIONAL COURT OF JUSTICE

REPORTS OF JUDGMENTS,
ADVISORY OPINIONS AND ORDERS

CASE CONCERNING PULP MILLS
ON THE RIVER URUGUAY

(ARGENTINA v. URUGUAY)

JUDGMENT OF 20 APRIL 2010 Mode ofﬁciel de citation:
Usines de pâte à papier sur le ﬂeuve Uruguay (Argentine c. Uruguay),
arrêt, C.I.J. Recueil 2010 ,p.14

Ofﬁcial citation:
Pulp Mills on the River Uruguay (Argentina v. Uruguay),
Judgment, I.C.J. Reports 2010 ,p.14

Sales number
ISSN 0074-4441 N de vente: 977
ISBN 978-92-1-071089-3 20 AVRIL 2010

ARRE|T

USINES DE P|TE v PAPIER SUR LE FLEUVE URUGUAY
(ARGENTINE c. URUGUAY)

PULP MILLS ON THE RIVER URUGUAY

(ARGENTINA v. URUGUAY)

20 APRIL 2010

JUDGMENT TABLE OF CONTENTS

Paragraphs

C HRONOLOGY OF THE PROCEDURE 1-24

I. EGAL F RAMEWORK AND F ACTS OF THECASE 25-47

A. Legal framework 26-27
B. CMB (ENCE) Project 28-36
C. Orion (Botnia) mill 37-47

II. COPE OF THE COURT’S URISDICTION 48-66

III. HE A LLEGED BREACH OF P ROCEDURAL O BLIGATIONS 67-158
A. The links between the procedural obligations and the sub-
stantive obligations 71-79
B. The procedural obligations and their interrelation 80-122

1. The nature and role of CARU 84-93
2. Uruguay’s obligation to inform CARU 94-111
3. Uruguay’s obligation to notify the plans to the other

party 112-122
C. Whether the Parties agreed to derogate from the procedural
obligations set out in the 1975 Statute 123-150

1. The “understanding” of 2 March 2004 between Argen-
tina and Uruguay 125-131
2. The agreement setting up the High-Level Technical
Group (the GTAN) 132-150

D. Uruguay’s obligations following the end of the negotiation
period 151-158

IV. SUBSTANTIVE OBLIGATIONS 159-266

A. Burden of proof and expert evidence 160-168
B. Alleged violations of substantive obligations 169-266
1. The obligation to contribute to the optimum and rational
utilization of the river (Article 1) 170-177

2. The obligation to ensure that the management of the soil
and woodland does not impair the régime of the river or
the quality of its waters (Article 35) 178-180
3. The obligation to co-ordinate measures to avoid changes
in the ecological balance (Article 36) 181-189
4. The obligation to prevent pollution and preserve the
aquatic environment (Article 41) 190-266

(a) Environmental Impact Assessment 203-219

(i) The siting of the Orion (Botnia) mill at Fray
Bentos 207-214
(ii) Consultation of the affected populations 215-219

4 (b) Question of the production technology used in the
Orion (Botnia) mill 220-228
(c) Impact of the discharges on the quality of the waters

of the river 229-259
(i) Dissolved oxygen 238-239
(ii) Phosphorus 240-250

(iii) Phenolic substances 251-254
(iv) Presence of nonylphenols in the river environ-
ment 255-257
(v) Dioxins and furans 258-259

(d) Effects on biodiversity 260-262
(e) Air pollution 263-264
(f) Conclusions on Article 41 265
(g) Continuing obligations: monitoring 266

V. THE C LAIMSM ADE BY THE PARTIES IT HEIRF INALSUBMISSIONS 267-281

O PERATIVECLAUSE 282

5 ABBREVIATIONS AND ACRONYMS

AAP “Autorización Ambiental Previa” (initialenvironmental

authorization)
ADCP Acoustic Doppler Current Proﬁler
AOX Adsorbable Organic Halogens
BAT Best Available Techniques (or Technology)
Botnia “Botnia S.A.” and “Botnia Fray Bentos S.A.” (two companies
formed under Uruguayan law by the Finnish company Oy
Metsä-Botnia AB)
CARU “Comisión Administradora del Río Uruguay” (Administrative
Commission of the River Uruguay)
CIS Cumulative Impact Study (prepared in September 2006 at the
request of the International Finance Corporation)
CMB Celulosas de M’Bopicuá S.A.” (a company formed under Uru-
guayan law by the Spanish company ENCE)
CMB (ENCE) Pulp mill planned at Fray Bentos by the Spanish company
ENCE, which formed the Uruguayan company CMB for that
purpose

DINAMA “Dirección Nacional de Medio Ambiente” (National Directo-
rate for the Environment of the Uruguayan Government)
ECF Elemental Chlorine-Free
EIA Environmental Impact Assessment
ENCE “Empresa Nacional de Celulosas de España” (Spanish com-
pany which formed the company CMB under Uruguayan law)
ESAP Environmental and Social Action Plan
GTAN “Grupo Técnico de Alto Nivel” (High-Level Technical Group
established in 2005 by Argentina and Uruguay to resolve their
dispute over the CMB (ENCE) and Orion (Botnia) mills)
IFC International Finance Corporation
IPPC-BAT Integrated Pollution Prevention and Control Reference Docu-
ment on Best Available Techniques in the Pulp and Paper
Industry
MVOTMA “Ministerio de Vivienda, Ordenamiento Territorial y Medio
Ambiente” (Uruguayan Ministry of Housing, Land Use Plan-

ning and Environmental Affairs)
Orion (Botnia) Pulp mill built at Fray Bentos by the Finnish company Oy
Metsä-Botnia AB, which formed the Uruguayan companies
Botnia S.A. and Botnia Fray Bentos S.A. for that purpose
OSE “Obras Sanitarias del Estado” (Uruguay’s State Agency for
Sanitary Works)
POPs Persistent Organic Pollutants
PROCEL “Plan de Monitoreo de la Calidad Ambiental en el Río Uru-
guay en áreas de Plantas Celulósicas” (Plan for monitoring
water quality in the area of the pulp mills set up under CARU)

6PROCON “Programa de Calidad de Aguas y Control de la Contami-
nación del Río Uruguay” (Water quality and pollution control
programme set up under CARU)

7 INTERNATIONAL COURT OF JUSTICE

YEAR 2010 2010
20 April
General List
20 April 2010 No. 135

CASE CONCERNING PULP MILLS

ON THE RIVER URUGUAY

(ARGENTINA v. URUGUAY)

Legal framework and facts of the case.
1961 Treaty of Montevideo — 1975 Statute of the River Uruguay — Estab-
lishment of the Administrative Commission of the River Uruguay (CARU) —
CMB (ENCE) pulp mill project — Orion (Botnia) pulp mill project — Port
terminal at Nueva Palmira — Subject of the dispute.

*

Scope of the Court’s jurisdiction.
Compromissory clause (Article 60 of the 1975 Statute) — Provisions of the
1975 Statute and jurisdiction ratione materiae — Lack of jurisdiction for the
Court to consider allegations concerning noise and visual pollution or bad
odours (Article 36 of the 1975 Statute) — Air pollution and impact on the qual-
ity of the waters of the river addressed under substantive obligations.

Article 1 of the 1975 Statute — Deﬁnition of the purpose of the 1975 Stat-
ute — Joint machinery necessary for the optimum and rational utilization of the
river — Signiﬁcance of the reference to the “rights and obligations arising from
treaties and other international agreements in force for each of the parties” —
Original Spanish text — Statute adopted by the parties in observance of their
respective international commitments.
Article 41 (a) of the 1975 Statute — Original Spanish text — Absence of a
“referral clause” having the effect of incorporating within the ambit of the Stat-
ute the obligations of the parties under international agreements and other
norms envisaged in the Statute — Obligation for the parties to exercise their
regulatory powers, in conformity with applicable international agreements, for
the protection and preservation of the aquatic environment of the River Uru-

guay — Rules for interpreting the 1975 Statute — Article 31 of the Vienna

8Convention on the Law of Treaties — Distinction between taking account of
other international rules in the interpretation of the 1975 Statute and the scope
of the jurisdiction of the Court under Article 60 of the latter.

*

Alleged breach of procedural obligations.
Question of links between the procedural obligations and the substantive obli-
gations — Object and purpose of the 1975 Statute — Optimum and rational
utilization of the River Uruguay — Sustainable development — Co-operation
between the parties in jointly managing the risks of damage to the environ-
ment — Existence of a functional link, in regard to prevention, between the pro-
cedural obligations and the substantive obligations — Responsibility in the event
of breaches of either category.
Interrelation of the various procedural obligations laid down by Articles 7 to
12 of the 1975 Statute — Original Spanish text of Article 7 — Obligation to
inform, notify and negotiate as an appropriate means of achieving the objective
of optimum and rational utilization of the river as a shared resource — Legal
personality of CARU — Central role of CARU in the joint management of the

river and obligation of the parties to co-operate.
Obligation to inform CARU (Article 7, ﬁrst paragraph, of the 1975 Stat-
ute) — Works subject to this obligation — Link between the obligation to
inform CARU, co-operation between the parties and the obligation of preven-
tion — Determination by CARU on a preliminary basis of whether there is a
risk of signiﬁcant damage to the other party — Content of the information to be
transmitted to CARU — Obligation to inform CARU before issuing of the ini-
tial environmental authorization — Provision of information to CARU by pri-
vate operators cannot substitute for the obligation to inform laid down by the
1975 Statute — Breach by Uruguay of the obligation to inform CARU.
Obligation to notify the plans to the other party (Article 7, second and third
paragraphs, of the 1975 Statute) — Need for a full environmental impact
assessment (EIA) — Notiﬁcation of the EIA to the other party, through

CARU, before any decision on the environmental viability of the plan — Breach
by Uruguay of the obligation to notify the plans to Argentina.

Question of whether the Parties agreed to derogate from the procedural obli-
gations — “Understanding” of 2 March 2004 — Content and scope — Since
Uruguay did not comply with it, the “understanding” cannot be regarded as
having had the effect of exempting Uruguay from compliance with the proce-
dural obligations — Agreement setting up the High-Level Technical Group
(GTAN) — Referral to the Court on the basis of Article 12 or Article 60 of the
1975 Statute: no practical distinction — The agreement to set up the GTAN
had the aim of enabling the negotiations provided for in Article 12 of the 1975
Statute to take place, but did not derogate from other procedural obligations —
In accepting the creation of the GTAN, Argentina did not give up the procedural

rights belonging to it by virtue of the Statute, nor the possibility of invoking
Uruguay’s responsibility; nor did Argentina consent to suspending the operation
of the procedural provisions of the Statute (Article 57 of the Vienna Convention
on the Law of Treaties) — Obligation to negotiate in good faith — “No con-
struction obligation” during the negotiation period — Preliminary work
approved by Uruguay — Breach by Uruguay of the obligation to negotiate laid
down by Article 12 of the 1975 Statute.

9 Obligations of Uruguay following the end of the negotiation period — Scope
of Article 12 of the 1975 Statute — Absence of a “no construction obligation”
following the end of the negotiation period and during the judicial settlement
phase.

*

Alleged breaches of substantive obligations.
Burden of proof — Precautionary approach without reversal of the burden of
proof — Expert evidence — Reports commissioned by the Parties — Independ-
ence of experts — Consideration of the facts by the Court — Experts appearing
as counsel at the hearings — Question of witnesses, experts and expert wit-
nesses.
Optimum and rational utilization of the River Uruguay — Article 1 of the
1975 Statute sets out the purpose of the instrument and does not lay down
speciﬁc rights and obligations — Obligation to comply with the obligations
prescribed by the Statute for the protection of the environment and the joint
management of the river — Regulatory function of CARU — Interconnected-
ness between equitable and reasonable utilization of the river as a shared

resource and the balance between economic development and environmental
protection that is the essence of sustainable development (Article 27 of the 1975
Statute).
Obligation to ensure that the management of the soil and woodland does not
impair the régime of the river or the quality of its waters (Article 35 of the 1975
Statute) — Contentions of Argentina not established.
Obligation to co-ordinate measures to avoid changes to the ecological balance
(Article 36 of the 1975 Statute) — Requirement of individual action by each
party and co-ordination through CARU — Obligation of due diligence —
Argentina has not convincingly demonstrated that Uruguay has refused to
engage in the co-ordination envisaged by Article 36 of the 1975 Statute.

Obligation to prevent pollution and preserve the aquatic environment — Norm-

ative content of Article 41 of the 1975 Statute — Obligation for each party to
adopt rules and measures to protect and preserve the aquatic environment and,
in particular, to prevent pollution — The rules and measures prescribed by each
party must be in accordance with applicable international agreements and in
keeping, where relevant, with the guidelines and recommendations of interna-
tional technical bodies — Due diligence obligation to prescribe rules and meas-
ures and to apply them — Deﬁnition of pollution given in Article 40 of the
1975 Statute — Regulatory action of CARU (Article 56 of the 1975 Statute),
complementing that of each party — CARU Digest — Rules by which the exist-
ence of any harmful effects is to be determined: 1975 Statute, CARU Digest,
domestic law of each party within the limits prescribed by the 1975 Statute.

Environmental impact assessment (EIA) — Obligation to conduct an EIA —
Scope and content of the EIA — Referral to domestic law — Question of the
choice of mill site as part of the EIA — The Court is not convinced by Argen-
tina’s argument that an assessment of possible sites was not carried out —
Receiving capacity of the river at Fray Bentos and reverse ﬂows — The CARU
water quality standards take account of the geomorphological and hydrological
characteristics of the river and the receiving capacity of its waters — Question

10of consultation of the affected populations as part of the EIA — No legal obli-
gation to consult the affected populations arises from the instruments invoked
by Argentina — Consultation by Uruguay of the affected populations did indeed
take place.

Production technology used in the Orion (Botnia) mill — No evidence to sup-

port Argentina’s claim that the Orion (Botnia) mill is not BAT-compliant in
terms of the discharges of efﬂuent for each tonne of pulp produced — From the
data collected after the start-up of the Orion (Botnia) mill, it does not appear
that the discharges from it have exceeded the prescribed limits.

Impact of the discharges on the quality of the waters of the river — Post-
operational monitoring — Dissolved oxygen — Phosphorus — Algal blooms —
Phenolic substances — Presence of nonylphenols in the river environment —
Dioxins and furans — Alleged breaches not established.
Effects on biodiversity — Insufﬁcient evidence to conclude that Uruguay
breached the obligation to protect the aquatic environment, including its fauna
and ﬂora.
Air pollution — Indirect pollution from deposits into the aquatic environ-

ment — Insufﬁcient evidence.
On the basis of the evidence submitted, no breach by Uruguay of Article 41 of
the 1975 Statute.
Continuing obligations: monitoring — Obligation of the Parties to enable
CARU to exercise on a continuous basis the powers conferred on it by the
1975 Statute — Obligation of Uruguay to continue monitoring the operation of
the Orion (Botnia) plant — Obligation of the Parties to continue their co-op-
eration through CARU.

*
Claims made by the Parties in their ﬁnal submissions.
Claims of Argentina — Breach of procedural obligations — Finding of

wrongful conduct and satisfaction — Forms of reparation other than compensa-
tion not excluded by the 1975 Statute — Restitution as a form of reparation
for injury — Deﬁnition — Limits — Form of reparation appropriate to the
injury suffered, taking into account the nature of the wrongful act — Restitution
in the form of the dismantling of the Orion (Botnia) mill not appropriate
where only breaches of procedural obligations have occurred — No breach
of substantive obligations and rejection of Argentina’s other claims — No
special circumstances requiring the ordering of assurances and guarantees
of non-repetition.

Uruguay’s request for conﬁrmation of its right to continue operating the
Orion (Botnia) plant — No practical signiﬁcance.

*

Obligation of the Parties to co-operate with each other, on the terms set out
in the 1975 Statute, to ensure the achievement of its object and purpose — Joint
action of the Parties through CARU and establishment of a real community of
interests and rights in the management of the River Uruguay and in the protec-
tion of its environment.

11 JUDGMENT

Present: Vice-President TOMKA , Acting President ; Judges KOROMA ,
A L-KHASAWNEH ,S IMMA,A BRAHAM ,K EITH,S EPÚLVEDA-A MOR,
B ENNOUNA ,S KOTNIKOV,C ANÇADO TRINDADE ,Y USUF,G REENWOOD ;
Judges ad hoc TORRES B ERNÁRDEZ,V INUESA; Registrar OUVREUR .

In the case concerning pulp mills on the River Uruguay,

between

the Argentine Republic,

represented by
H.E. Ms Susana Ruiz Cerutti, Ambassador, Legal Adviser to the Ministry of
Foreign Affairs, International Trade and Worship,

as Agent;
H.E. Mr. Horacio A. Basabe, Ambassador, Director of the Argentine Insti-
tute for Foreign Service, former Legal Adviser to the Ministry of Foreign
Affairs, International Trade and Worship, Member of the Permanent

Court of Arbitration,
H.E. Mr. Santos Goñi Marenco, Ambassador of the Argentine Republic to
the Kingdom of the Netherlands,
as Co-Agents;

Mr. Alain Pellet, Professor at the University of Paris Ouest, Nanterre-
La Défense, member and former Chairman of the International Law Com-
mission, associate member of the Institut de droit international,
Mr. Philippe Sands, Q.C., Professor of International Law at University Col-

lege London, Barrister at Matrix Chambers, London,
Mr. Marcelo Kohen, Professor of International Law at the Graduate Insti-
tute of International and Development Studies, Geneva, associate member
of the Institut de droit international,
Ms Laurence Boisson de Chazournes, Professor of International Law at the
University of Geneva,
Mr. Alan Béraud, Minister at the Embassy of the Argentine Republic to the

European Union, former Legal Adviser to the Ministry of Foreign Affairs,
International Trade and Worship,
Mr. Daniel Müller, Researcher at the Centre de droit international de
Nanterre (CEDIN), University of Paris Ouest, Nanterre-La Défense,
as Counsel and Advocates;

Mr. Homero Bibiloni, Federal Secretary for the Environment and Sustain-
able Development,

as Governmental Authority;
Mr. Esteban Lyons, National Director of Environmental Control, Secre-
tariat of the Environment and Sustainable Development,
Mr. Howard Wheater, Ph.D. in Hydrology from Bristol University, Profes-

sor of Hydrology at Imperial College and Director of the Imperial College
Environment Forum,

12 Mr. Juan Carlos Colombo, Ph.D. in Oceanography from the University of
Quebec, Professor at the Faculty of Sciences and Museum of the National
University of La Plata, Director of the Laboratory of Environmental
Chemistry and Biogeochemistry at the National University of La Plata,
Mr. Neil McIntyre, Ph.D. in Environmental Engineering, Senior Lecturer in
Hydrology at Imperial College London,

Ms Inés Camilloni, Ph.D. in Atmospheric Sciences, Professor of Atmos-
pheric Sciences in the Faculty of Sciences of the University of Buenos
Aires, Senior Researcher at the National Research Council (CONICET),

Mr. Gabriel Raggio, Doctor in Technical Sciences of the Swiss Federal Insti-
tute of Technology Zurich (ETHZ) (Switzerland), Independent Consult-
ant,

as Scientiﬁc Advisers and Experts;
Mr. Holger Martinsen, Minister at the Ofﬁce of the Legal Adviser, Ministry
of Foreign Affairs, International Trade and Worship,
Mr. Mario Oyarzábal, Embassy Counsellor, member of the Ofﬁce of the
Legal Adviser, Ministry of Foreign Affairs, International Trade and Wor-
ship,

Mr. Fernando Marani, Second Secretary, Embassy of the Argentine Repub-
lic in the Kingdom of the Netherlands,
Mr. Gabriel Herrera, Embassy Secretary, member of the Ofﬁce of the Legal
Adviser, Ministry of Foreign Affairs, International Trade and Worship,

Ms Cynthia Mulville, Embassy Secretary, member of the Ofﬁce of the Legal
Adviser, Ministry of Foreign Affairs, International Trade and Worship,

MsKateCook,BarristeratMatrixChambers,London,specializinginenviron-
mental law and law relating to development,
Ms Mara Tignino, Ph.D. in Law, Researcher at the University of Geneva,
Mr. Magnus Jesko Langer, teaching and research assistant, Graduate Insti-
tute of International and Development Studies, Geneva,

as Legal Advisers,

and

the Eastern Republic of Uruguay,

represented by
H.E. Mr. Carlos Gianelli, Ambassador of the Eastern Republic of Uruguay
to the United States of America,

as Agent;

H.E. Mr. Carlos Mora Medero, Ambassador of the Eastern Republic of
Uruguay to the Kingdom of the Netherlands,
as Co-Agent;

Mr. Alan Boyle, Professor of International Law at the University of Edin-
burgh, Member of the English Bar,
Mr. Luigi Condorelli, Professor at the Faculty of Law, University of Flor-
ence,

13Mr. Lawrence H. Martin, Foley Hoag LLP, Member of the Bars of the
United States Supreme Court, the District of Columbia and the Common-
wealth of Massachusetts,
Mr. Stephen C. McCaffrey, Professor at the McGeorge School of Law, Uni-
versity of the Paciﬁc, California, former Chairman of the International
Law Commission and Special Rapporteur for the Commission’s work on

the law of non-navigational uses of international watercourses,

Mr. Alberto Pérez Pérez, Professor in the Faculty of Law, University of the
Republic, Montevideo,
Mr. Paul S. Reichler, Foley Hoag LLP, Member of the Bars of the United
States Supreme Court and the District of Columbia,

as Counsel and Advocates;
Mr. Marcelo Cousillas, Legal Counsel at the National Directorate for the
Environment, Ministry of Housing, Land Use Planning and Environmen-
tal Affairs,
Mr. César Rodriguez Zavalla, Chief of Cabinet, Ministry of Foreign Affairs,

Mr. Carlos Mata, Deputy Director of Legal Affairs, Ministry of Foreign
Affairs,
Mr. Marcelo Gerona, Counsellor at the Embassy of the Eastern Republic of
Uruguay in the Kingdom of the Netherlands,
Mr. Eduardo Jiménez de Aréchaga, Attorney at Law, admitted to the Bar of
the Eastern Republic of Uruguay and Member of the Bar of New York,
Mr. Adam Kahn, Foley Hoag LLP, Member of the Bar of the Common-
wealth of Massachusetts,
Mr. Andrew Loewenstein, Foley Hoag LLP, Member of the Bar of the Com-
monwealth of Massachusetts,
Ms Analia Gonzalez, LL.M., Foley Hoag LLP, admitted to the Bar of the
Eastern Republic of Uruguay,

Ms Clara E. Brillembourg, Foley Hoag LLP, Member of the Bars of the Dis-
trict of Columbia and New York,
Ms Cicely Parseghian, Foley Hoag LLP, Member of the Bar of the Com-
monwealth of Massachusetts,
Mr. Pierre Harcourt, Ph.D. candidate, University of Edinburgh,
Mr. Paolo Palchetti, Associate Professor at the School of Law, University of
Macerata,
Ms Maria E. Milanes-Murcia, M.A., LL.M., J.S.D. Candidate at the
McGeorge School of Law, University of the Paciﬁc, California, Ph.D.
Candidate, University of Murcia, admitted to the Bar of Spain,

as Assistant Counsel;
Ms Alicia Torres, National Director for the Environment at the Ministry of

Housing, Land Use Planning and Environmental Affairs,
Mr. Eugenio Lorenzo, Technical Consultant for the National Directorate for
the Environment, Ministry of Housing, Land Use Planning and Environ-
mental Affairs,
Mr. Cyro Croce, Technical Consultant for the National Directorate for the
Environment, Ministry of Housing, Land Use Planning and Environmen-
tal Affairs,

14 Ms Raquel Piaggio, State Agency for Sanitary Works (OSE), Technical Con-
sultant for the National Directorate for the Environment, Ministry of
Housing, Land Use Planning and Environmental Affairs,

Mr. Charles A. Menzie, Ph.D., Principal Scientist and Director of the Eco-

Sciences Practice at Exponent, Inc., Alexandria, Virginia,
Mr. Neil McCubbin, Eng., B.Sc. (Eng.), 1st Class Honours, Glasgow, Asso-
ciate of the Royal College of Science and Technology, Glasgow,
as Scientiﬁc Advisers and Experts,

T HE C OURT,

composed as above,
after deliberation,

delivers the following Judgment:

1. On 4 May 2006, the Argentine Republic (hereinafter “Argentina”) ﬁled in
the Registry of the Court an Application instituting proceedings against the
Eastern Republic of Uruguay (hereinafter “Uruguay”) in respect of a dispute
concerning the breach, allegedly committed by Uruguay, of obligations under
the Statute of the River Uruguay (United Nations, Treaty Series (UNTS),
Vol. 1295, No. I-21425, p. 340), a treaty signed by Argentina and Uruguay at
Salto (Uruguay) on 26 February 1975 and having entered into force on 18 Sep-
tember 1976 (hereinafter the “1975 Statute”); in the Application, Argentina
stated that this breach arose out of “the authorization, construction and future
commissioning of two pulp mills on the River Uruguay”, with reference in par-

ticular to “the effects of such activities on the quality of the waters of the River
Uruguay and on the areas affected by the river”.
In its Application, Argentina, referring to Article 36, paragraph 1, of the
Statute of the Court, seeks to found the jurisdiction of the Court on Article 60,
paragraph 1, of the 1975 Statute.
2. Pursuant to Article 40, paragraph 2, of the Statute of the Court, the Reg-
istrar communicated the Application forthwith to the Government of Uruguay.
In accordance with paragraph 3 of that Article, the Secretary-General of the
United Nations was notiﬁed of the ﬁling of the Application.
3. On 4 May 2006, immediately after the ﬁling of the Application, Argentina
also submitted a request for the indication of provisional measures based on

Article 41 of the Statute and Article 73 of the Rules of Court. In accordance
with Article 73, paragraph 2, of the Rules of Court, the Registrar transmitted a
certiﬁed copy of this request forthwith to the Government of Uruguay.

4. On 2 June 2006, Uruguay transmitted to the Court a CD-ROM contain-
ing the electronic version of two volumes of documents relating to the Argen-
tine request for the indication of provisional measures, entitled “Observations
of Uruguay” (of which paper copies were subsequently received); a copy of
these documents was immediately sent to Argentina.
5. On 2 June 2006, Argentina transmitted to the Court various docu-
ments, including a video recording, and, on 6 June 2006, it transmitted further

documents; copies of each series of documents were immediately sent to Uru-
guay.
6. On 6 and 7 June 2006, various communications were received from the

15Parties, whereby each Party presented the Court with certain observations on
the documents submitted by the other Party. Uruguay objected to the produc-
tion of the video recording submitted by Argentina. The Court decided not to
authorize the production of that recording at the hearings.
7. Since the Court included upon the Bench no judge of the nationality of
the Parties, each of them exercised its right under Article 31, paragraph 3, of

the Statute to choose a judge ad hoc to sit in the case. Argentina chose
Mr. Raúl Emilio Vinuesa, and Uruguay chose Mr. Santiago Torres Bernárdez.

8. By an Order of 13 July 2006, the Court, having heard the Parties, found
“that the circumstances, as they [then] present[ed] themselves to [it], [we]re not
such as to require the exercise of its power under Article 41 of the Statute to
indicate provisional measures”.
9. By another Order of the same date, the Court, taking account of the views
of the Parties, ﬁxed 15 January 2007 and 20 July 2007, respectively, as the time-
limits for the ﬁling of a Memorial by Argentina and a Counter-Memorial by
Uruguay; those pleadings were duly ﬁled within the time-limits so prescribed.

10. On 29 November 2006, Uruguay, invoking Article 41 of the Statute and

Article 73 of the Rules of Court, in turn submitted a request for the indication
of provisional measures. In accordance with Article 73, paragraph 2, of the
Rules of Court, the Registrar transmitted a certiﬁed copy of this request forth-
with to the Argentine Government.
11. On 14 December 2006, Uruguay transmitted to the Court a volume of
documents concerning the request for the indication of provisional measures,
entitled “Observations of Uruguay”; a copy of these documents was immedi-
ately sent to Argentina.
12. On 18 December 2006, before the opening of the oral proceedings,
Argentina transmitted to the Court a volume of documents concerning Uru-
guay’s request for the indication of provisional measures; the Registrar imme-
diately sent a copy of these documents to the Government of Uruguay.
13. By an Order of 23 January 2007, the Court, having heard the Parties,

found “that the circumstances, as they [then] present[ed] themselves to [it],
[we]re not such as to require the exercise of its power under Article 41 of the
Statute to indicate provisional measures”.
14. By an Order of 14 September 2007, the Court, taking account of the
agreement of the Parties and of the circumstances of the case, authorized the
submission of a Reply by Argentina and a Rejoinder by Uruguay, and ﬁxed
29 January 2008 and 29 July 2008 as the respective time-limits for the ﬁling of
those pleadings. The Reply of Argentina and the Rejoinder of Uruguay were
duly ﬁled within the time-limits so prescribed.
15. By letters dated 16 June 2009 and 17 June 2009 respectively, the Gov-
ernments of Uruguay and Argentina notiﬁed the Court that they had come to
an agreement for the purpose of producing new documents pursuant to Arti-
cle 56 of the Rules of Court. By letters of 23 June 2009, the Registrar informed

the Parties that the Court had decided to authorize them to proceed as they had
agreed. The new documents were duly ﬁled within the agreed time-limit.

16. On 15 July 2009, each of the Parties, as provided for in the agreement
between them and with the authorization of the Court, submitted comments on
the new documents produced by the other Party. Each Party also ﬁled docu-
ments in support of these comments.

16 17. In accordance with Article 53, paragraph 2, of the Rules of Court, the
Court decided, after ascertaining the views of the Parties, that copies of the
pleadings and documents annexed would be made available to the public as
from the opening of the oral proceedings.
18. By letter of 15 September 2009, Uruguay, referring to Article 56, para-
graph 4, of the Rules of Court and to Practice Direction IXbis, communicated

documents to the Court, forming part of publications readily available, on
which it intended to rely during the oral proceedings. Argentina made no objec-
tion with regard to these documents.
19. By letter of 25 September 2009, the Argentine Government, referring to
Article 56 of the Rules of Court and to Practice Direction IX, paragraph 2, sent
new documents to the Registry which it wished to produce. By letter of 28 Sep-
tember 2009, the Government of Uruguay informed the Court that it was
opposed to the production of these documents. It further indicated that if,
nevertheless, the Court decided to admit the documents in question into the
record of the case, it would present comments on them and submit documents
in support of those comments. By letters dated 28 September 2009, the Regis-
trar informed the Parties that the Court did not consider the production of the
new documents submitted by the Argentine Government to be necessary within

the meaning of Article 56, paragraph 2, of the Rules of Court, and that it had
not moreover identiﬁed any exceptional circumstance (Practice Direction IX,
paragraph 3) which justiﬁed their production at that stage of the proceedings.

20. Public hearings were held between 14 September 2009 and 2 October
2009, at which the Court heard the oral arguments and replies of:

For Argentina: H.E. Ms Susana Ruiz Cerutti,
Mr. Alain Pellet,
Mr. Philippe Sands,
Mr. Howard Wheater,
Ms Laurence Boisson de Chazournes,
Mr. Marcelo Kohen,
Mr. Alan Béraud,
Mr. Juan Carlos Colombo,
Mr. Daniel Müller.

For Uruguay: H.E. Mr. Carlos Gianelli,
Mr. Alan Boyle,
Mr. Paul S. Reichler,
Mr. Neil McCubbin,
Mr. Stephen C. McCaffrey,
Mr. Lawrence H. Martin,
Mr. Luigi Condorelli.

21. At the hearings, Members of the Court put questions to the Parties,
to which replies were given orally and in writing, in accordance with Arti-
cle 61, paragraph 4, of the Rules of Court. Pursuant to Article 72 of the
Rules of Court, one of the Parties submitted written comments on a written
reply provided by the other and received after the closure of the oral pro-

ceedings.

*

17 22. In its Application, the following claims were made by Argentina:

“On the basis of the foregoing statement of facts and law, Argentina,
while reserving the right to supplement, amend or modify the present
Application in the course of the subsequent procedure, requests the Court
to adjudge and declare:
1. that Uruguay has breached the obligations incumbent upon it under
the 1975 Statute and the other rules of international law to which that
instrument refers, including but not limited to:

(a) the obligation to take all necessary measures for the optimum and
rational utilization of the River Uruguay;
(b) the obligation of prior notiﬁcation to CARU and to Argentina;
(c) the obligation to comply with the procedures prescribed in Chap-
ter II of the 1975 Statute;
(d) the obligation to take all necessary measures to preserve the
aquatic environment and prevent pollution and the obligation to
protect biodiversity and ﬁsheries, including the obligation to pre-
pare a full and objective environmental impact study;

(e) the obligation to co-operate in the prevention of pollution and the
protection of biodiversity and of ﬁsheries; and
2. that, by its conduct, Uruguay has engaged its international responsibil-
ity to Argentina;
3. that Uruguay shall cease its wrongful conduct and comply scrupulously
in future with the obligations incumbent upon it; and
4. that Uruguay shall make full reparation for the injury caused by its
breach of the obligations incumbent upon it.

Argentina reserves the right to amplify or amend these requests at a sub-
sequent stage of the proceedings.”

23. In the written proceedings, the following submissions were presented by
the Parties:
On behalf of the Government of Argentina,

in the Memorial:
“For all the reasons described in this Memorial, the Argentine Republic
requests the International Court of Justice:

1. to ﬁnd that by unilaterally authorizing the construction of the CMB
and Orion pulp mills and the facilities associated with the latter on the
left bank of the River Uruguay, in breach of the obligations resulting
from the Statute of 26 February 1975, the Eastern Republic of
Uruguay has committed the internationally wrongful acts set out in
Chapters IV and V of this Memorial, which entail its international
responsibility;
2. to adjudge and declare that, as a result, the Eastern Republic of Uruguay
must:

(i) cease immediately the internationally wrongful acts referred to
above;
(ii) resume strict compliance with its obligations under the Statute of
the River Uruguay of 1975;

18 (iii) re-establish on the ground and in legal terms the situation that
existed before the internationally wrongful acts referred to above
were committed;
(iv) pay compensation to the Argentine Republic for the damage

caused by these internationally wrongful acts that would not be
remedied by that situation being restored, of an amount to be
determined by the Court at a subsequent stage of these proceed-
ings;
(v) provide adequate guarantees that it will refrain in future from pre-
venting the Statute of the River Uruguay of 1975 from being
applied, in particular the consultation procedure established by
Chapter II of that Treaty.

The Argentine Republic reserves the right to supplement or amend these
submissions should the need arise, in the light of the development of the
situation. This would in particular apply if Uruguay were to aggravate
the dispute , for example if the Orion mill were to be commissioned before
the end of these proceedings.

1 See the Order of the Court of 13 July 2006 on Argentina’s request for the indica-
tion of provisional measures, para. 82.”

in the Reply:

“For all the reasons described in its Memorial, which it fully stands by,
and in the present Reply, the Argentine Republic requests the Interna-
tional Court of Justice:

1. to ﬁnd that by authorizing
— the construction of the CMB mill;
— the construction and commissioning of the Orion mill and its asso-
ciated facilities on the left bank of the River Uruguay,

the Eastern Republic of Uruguay has violated the obligations incum-
bent on it under the Statute of the River Uruguay of 26 February 1975
and has engaged its international responsibility;
2. to adjudge and declare that, as a result, the Eastern Republic of Uru-

guay must:
(i) resume strict compliance with its obligations under the Statute of
the River Uruguay of 1975;
(ii) cease immediately the internationally wrongful acts by which it
has engaged its responsibility;
(iii) re-establish on the ground and in legal terms the situation that

existed before these internationally wrongful acts were committed;
(iv) pay compensation to the Argentine Republic for the damage
caused by these internationally wrongful acts that would not be
remedied by that situation being restored, of an amount to be
determined by the Court at a subsequent stage of these proceed-
ings;
(v) provide adequate guarantees that it will refrain in future from pre-
venting the Statute of the River Uruguay of 1975 from being
applied, in particular the consultation procedure established by
Chapter II of that Treaty.

19 The Argentine Republic reserves the right to supplement or amend these
submissions should the need arise, in the light of subsequent developments
in the case.”

On behalf of the Government of Uruguay,

in the Counter-Memorial:
“On the basis of the facts and arguments set out above, and reserving its
right to supplement or amend these Submissions, Uruguay requests that

the Court adjudge and declare that the claims of Argentina are rejected.”
In the Rejoinder:

“Based on all the above, it can be concluded that:

(a) Argentina has not demonstrated any harm, or risk of harm, to the
river or its ecosystem resulting from Uruguay’s alleged violations of
its substantive obligations under the 1975 Statute that would be suf-
ﬁcient to warrant the dismantling of the Botnia plant;

(b) the harm to the Uruguayan economy in terms of lost jobs and rev-
enue would be substantial;
(c) in light of points (a) and (b), the remedy of tearing the plant down
would therefore be disproportionately onerous, and should not be
granted;
(d) if the Court ﬁnds, notwithstanding all the evidence to the contrary,
that Uruguay has violated its procedural obligations to Argentina, it

can issue a declaratory judgment to that effect, which would consti-
tute an adequate form of satisfaction;
(e) if the Court ﬁnds, notwithstanding all the evidence to the contrary,
that the plant is not in complete compliance with Uruguay’s obliga-
tion to protect the river or its aquatic environment, the Court can
order Uruguay to take whatever additional protective measures are
necessary to ensure that the plant conforms to the Statute’s substan-
tive requirements;
(f) if the Court ﬁnds, notwithstanding all the evidence to the contrary,
that Uruguay has actually caused damage to the river or to Argen-
tina, it can order Uruguay to pay Argentina monetary compensation
under Articles 42 and 43 of the Statute; and
(g) the Court should issue a declaration making clear the Parties are obli-

gated to ensure full respect for all the rights in dispute in this case,
including Uruguay’s right to continue operating the Botnia plant in
conformity with the provisions of the 1975 Statute.

Submissions

On the basis of the facts and arguments set out above, and reserving its
right to supplement or amend these Submissions, Uruguay requests that
the Court adjudge and declare that the claims of Argentina are rejected,
and Uruguay’s right to continue operating the Botnia plant in conformity
with the provisions of the 1975 Statute is afﬁrmed.”

24. At the oral proceedings, the following ﬁnal submissions were presented
by the Parties:

20On behalf of the Government of Argentina,

at the hearing of 29 September 2009:
“For all the reasons described in its Memorial, in its Reply and in the
oral proceedings, which it fully stands by, the Argentine Republic requests
the International Court of Justice:

1. to ﬁnd that by authorizing

— the construction of the ENCE mill;
— the construction and commissioning of the Botnia mill and its asso-
ciated facilities on the left bank of the River Uruguay,
the Eastern Republic of Uruguay has violated the obligations incum-
bent on it under the Statute of the River Uruguay of 26 February 1975
and has engaged its international responsibility;

2. to adjudge and declare that, as a result, the Eastern Republic of Uru-
guay must:
(i) resume strict compliance with its obligations under the Statute of

the River Uruguay of 1975;
(ii) cease immediately the internationally wrongful acts by which it
has engaged its responsibility;
(iii) re-establish on the ground and in legal terms the situation that
existed before these internationally wrongful acts were committed;
(iv) pay compensation to the Argentine Republic for the damage
caused by these internationally wrongful acts that would not be
remedied by that situation being restored, of an amount to be
determined by the Court at a subsequent stage of these proceed-

ings;
(v) provide adequate guarantees that it will refrain in future from pre-
venting the Statute of the River Uruguay of 1975 from being
applied, in particular the consultation procedure established by
Chapter II of that Treaty.”

On behalf of the Government of Uruguay,
at the hearing of 2 October 2009:

“On the basis of the facts and arguments set out in Uruguay’s Counter-
Memorial, Rejoinder and during the oral proceedings, Uruguay requests
that the Court adjudge and declare that the claims of Argentina are
rejected, and Uruguay’s right to continue operating the Botnia plant in
conformity with the provisions of the 1975 Statute is afﬁrmed.”

* * *

I. LEGAL F RAMEWORK

AND F ACTS OF THE C ASE

25. The dispute before the Court has arisen in connection with the
planned construction authorized by Uruguay of one pulp mill and the
construction and commissioning of another, also authorized by Uruguay,

21on the River Uruguay (see sketch-map No. 1 on p. 33 for the general
geographical context). After identifying the legal instruments concerning

the River Uruguay by which the Parties are bound, the Court will set out
the main facts of the case.

A. Legal Framework

26. The boundary between Argentina and Uruguay in the River Uru-
guay is deﬁned by the bilateral Treaty entered into for that purpose at
Montevideo on 7 April 1961 (UNTS, Vol. 635, No. 9074, p. 98). Arti-
cles 1 to 4 of the Treaty delimit the boundary between the Contracting

States in the river and attribute certain islands and islets in it to them.
Articles 5 and 6 concern the régime for navigation on the river. Article 7
provides for the establishment by the parties of a “régime for the use of
the river” covering various subjects, including the conservation of living
resources and the prevention of water pollution of the river. Articles 8 to
10 lay down certain obligations concerning the islands and islets and

their inhabitants.
27. The “régime for the use of the river” contemplated in Article 7 of
the 1961 Treaty was established through the 1975 Statute (see para-
graph 1 above). Article 1 of the 1975 Statute states that the parties
adopted it “in order to establish the joint machinery necessary for the

optimum and rational utilization of the River Uruguay, in strict observ-
ance of the rights and obligations arising from treaties and other inter-
national agreements in force for each of the parties”. After having thus
deﬁned its purpose (Article 1) and having also made clear the meaning of
certain terms used therein (Article 2), the 1975 Statute lays down rules

governing navigation and works on the river (Chapter II, Articles 3 to
13), pilotage (Chapter III, Articles 14 to 16), port facilities, unloading
and additional loading (Chapter IV, Articles 17 to 18), the safeguarding
of human life (Chapter V, Articles 19 to 23) and the salvaging of property
(Chapter VI, Articles 24 to 26), use of the waters of the river (Chap-

ter VII, Articles 27 to 29), resources of the bed and subsoil (Chapter VIII,
Articles 30 to 34), the conservation, utilization and development of other
natural resources (Chapter IX, Articles 35 to 39), pollution (Chapter X,
Articles 40 to 43), scientiﬁc research (Chapter XI, Articles 44 to 45), and
various powers of the parties over the river and vessels sailing on it
(Chapter XII, Articles 46 to 48). The 1975 Statute sets up the Adminis-

trative Commission of the River Uruguay (hereinafter “CARU”, from
the Spanish acronym for “Comisión Administradora del Río Uruguay”)
(Chapter XIII, Articles 49 to 57), and then establishes procedures for
conciliation (Chapter XIV, Articles 58 to 59) and judicial settlement of
disputes (Chapter XV, Article 60). Lastly, the 1975 Statute contains tran-

sitional (Chapter XVI, Articles 61 to 62) and ﬁnal (Chapter XVII, Arti-
cle 63) provisions.

22 Sketch-mapNo.1:

Generalgeographicac l ontext

Mercator Projection
i (33°30'S)
e
G WGS84
u Thissketch-maphas beenprepared
ae
g for illustrativepurposesonly.
a
c
ú

Gualeguaychú

Fray Bentos
(location of Orion (Botnia) mill)

ARGENTINA

RiverUruguay

URUGUAY

Nueva Palmira

BUENOSAIRES Rí
o d
ela
Pla
a MONTEVIDEO

23 B. CMB (ENCE) Project

28. The ﬁrst pulp mill at the root of the dispute was planned by “Celu-
losas de M’Bopicuá S.A.” (hereinafter “CMB”), a company formed by
the Spanish company ENCE (from the Spanish acronym for “Empresa
Nacional de Celulosas de España”, hereinafter “ENCE”). This mill, here-
inafter referred to as the “CMB (ENCE)” mill, was to have been built on

the left bank of the River Uruguay in the Uruguayan department of Río
Negro opposite the Argentine region of Gualeguaychú, more speciﬁcally
to the east of the city of Fray Bentos, near the “General San Martín”
international bridge (see sketch-map No. 2 on p. 35).
29. On 22 July 2002, the promoters of this industrial project

approached the Uruguayan authorities and submitted an environ-
mental impact assessment (“EIA” according to the abbreviation used by
the Parties) of the plan to Uruguay’s National Directorate for the
Environment (hereinafter “DINAMA”, from the Spanish acronym for
“Dirección Nacional de Medio Ambiente”). During the same period, rep-
resentatives of CMB, which had been specially formed to build the CMB

(ENCE) mill, informed the President of CARU of the project. The Presi-
dent of CARU wrote to the Uruguayan Minister of the Environment on
17 October 2002 seeking a copy of the environmental impact assessment
of the CMB (ENCE) project submitted by the promoters of this indus-
trial project. This request was reiterated on 21 April 2003. On

14 May 2003, Uruguay submitted to CARU a document entitled “Envi-
ronmental Impact Study, Celulosas de M’Bopicuá. Summary for public
release”. One month later, the CARU Subcommittee on Water Quality
and Pollution Control took notice of the document transmitted by
Uruguay and suggested that a copy thereof be sent to its technical

advisers for their opinions. Copies were also provided to the Parties’
delegations.

30. A public hearing, attended by CARU’s Legal Adviser and its tech-
nical secretary, was held on 21 July 2003 in the city of Fray Bentos con-

cerning CMB’s application for an environmental authorization. On
15 August 2003, CARU asked Uruguay for further information on vari-
ous points concerning the planned CMB (ENCE) mill. This request was
reiterated on 12 September 2003. On 2 October 2003, DINAMA submit-
ted its assessment report to the Uruguayan Ministry of Housing, Land
Use Planning and Environmental Affairs (hereinafter “MVOTMA”, from

the Spanish abbreviation for “Ministerio de Vivienda Ordenamiento Ter-
ritorial y Medio Ambiente”), recommending that CMB be granted an ini-
tial environmental authorization (“AAP” according to the Spanish abbre-
viation for “Autorización Ambiental Previa”) subject to certain condi-
tions. On 8 October 2003, CARU was informed by the Uruguayan

delegation that DINAMA would very shortly send CARU a report on
the CMB (ENCE) project.

24 built)

not

but

(planned

mill

mill
(ENCE) URUGUAY

CMB
GenralSn
M aríbrige (Botnia)

Orion

Lagoon
Inés

Bentos

Fray

ARGENTINA

Bay
augur
UrevR

Ñandubaysal and built)

.
mill(not
2: only
mill prepared
No.
been
(Botnia) S) purposes
(ENCE)r(33°tions
WGS84
lguychú Orion
RierGua
CMB Mercatorsketch-mapative
Sketch-map for
of This

planned
Gualeguaychú Siting
the

25 31. On 9 October 2003, MVOTMA issued an initial environmental
authorization to CMB for the construction of the CMB (ENCE) mill. On

the same date the Presidents of Argentina and Uruguay met at Anchorena
(Colonia, Uruguay). Argentina maintains that the President of Uruguay,
Jorge Battle, then promised his Argentine counterpart, Néstor Kirchner,
that no authorization would be issued before Argentina’s environmental
concerns had been addressed. Uruguay challenges this version of the

facts and contends that the Parties agreed at that meeting to deal with the
CMB (ENCE) project otherwise than through the procedure under Arti-
cles 7 to 12 of the 1975 Statute and that Argentina let it be known that it
was not opposed to the project per se. Argentina disputes these assertions.

32. The day after the meeting between the Heads of State of Argentina
and Uruguay, CARU declared its willingness to resume the technical
analyses of the CMB (ENCE) project as soon as Uruguay transmitted the
awaited documents. On 17 October 2003, CARU held an extraordinary
plenary meeting at the request of Argentina, at which Argentina

complained of Uruguay’s granting on 9 October 2003 of the initial envi-
ronmental authorization. Following the extraordinary meeting CARU
suspended work for more than six months, as the Parties could not agree
on how to implement the consultation mechanism established by the
1975 Statute.

33. On 27 October 2003, Uruguay transmitted to Argentina copies of
the environmental impact assessment submitted by ENCE on 22 July
2002, of DINAMA’s ﬁnal assessment report dated 2 October 2003 and of
the initial environmental authorization of 9 October 2003. Argentina
reacted by expressing its view that Article 7 of the 1975 Statute had not

been observed and that the transmitted documents did not appear
adequate to allow for a technical opinion to be expressed on the environ-
mental impact of the project. On 7 November 2003, further to a request
from the Ministry of Foreign Affairs of Argentina, Uruguay provided
Argentina with a copy of the Uruguayan Ministry of the Environment’s

entire ﬁle on the CMB (ENCE) project. On 23 February 2004, Argentina
forwarded all of this documentation received from Uruguay to CARU.

34. On 2 March 2004, the Parties’ Ministers for Foreign Affairs met in
Buenos Aires. On 15 May 2004, CARU resumed its work at an extra-
ordinary plenary meeting during which it took note of the ministerial

“understanding” which was reached on 2 March 2004. The Parties are at
odds over the content of this “understanding”. The Court will return to
this when it considers Argentina’s claims as to Uruguay’s breach of its
procedural obligations under the 1975 Statute (see paragraphs 67 to 158).

35. Following up on CARU’s extraordinary meeting of 15 May 2004,
the CARU Subcommittee on Water Quality and Pollution Control pre-

26pared a plan for monitoring water quality in the area of the pulp mills
(hereinafter the “PROCEL” plan from the Spanish acronym for “Plan de

Monitoreo de la Calidad Ambiental del Río Uruguay en Areas de Plan-
tas Celulósicas”). CARU approved the plan on 12 November 2004.

36. On 28 November 2005, Uruguay authorized preparatory work to
begin for the construction of the CMB (ENCE) mill (ground clearing).

On 28 March 2006, the project’s promoters decided to halt the work for
90 days. On 21 September 2006, they announced their intention not to
build the mill at the planned site on the bank of the River Uruguay.

C. Orion (Botnia) Mill

37. The second industrial project at the root of the dispute before the
Court was undertaken by “Botnia S.A.” and “Botnia Fray Bentos S.A.”
(hereinafter “Botnia”), companies formed under Uruguayan law in 2003

specially for the purpose by Oy Metsä-Botnia AB, a Finnish company.
This second pulp mill, called “Orion” (hereinafter the “Orion (Botnia)”
mill), has been built on the left bank of the River Uruguay, a few kilo-
metres downstream of the site planned for the CMB (ENCE) mill, and
also near the city of Fray Bentos (see sketch-map No. 2 on p. 35). It has

been operational and functioning since 9 November 2007.

38. After informing the Uruguayan authorities of this industrial
project in late 2003, the project promoters submitted an application to
them for an initial environmental authorization on 31 March 2004

and supplemented it on 7 April 2004. Several weeks later, on 29
and 30 April 2004, CARU members and Botnia representatives met
informally. Following that meeting, CARU’s Subcommittee on
Water Quality and Pollution Control suggested on 18 June 2004 that
Botnia expand on the information provided at the meeting. On

19 October 2004, CARU held another meeting with Botnia
representatives and again expressed the need for further information
on Botnia’s application to DINAMA for an initial environmental
authorization. On 12 November 2004, when approving the water quality
monitoring plan put forward by the CARU Subcommittee on Water
Quality and Pollution Control (see paragraph 35 above), CARU decided,

on the proposal of that subcommittee, to ask Uruguay to provide further
information on the application for an initial environmental authoriza-
tion. CARU transmitted this request for further information to Uruguay
by note dated 16 November 2004.

39. On 21 December 2004 DINAMA held a public hearing, attended

27by a CARU adviser, on the Orion (Botnia) project in Fray Bentos.
DINAMA adopted its environmental impact study of the planned Orion

(Botnia) mill on 11 February 2005 and recommended that the initial envi-
ronmental authorization be granted, subject to certain conditions.
MVOTMA issued the initial authorization to Botnia on 14 February 2005
for the construction of the Orion (Botnia) mill and an adjacent port ter-
minal. At a CARU meeting on 11 March 2005, Argentina questioned

whether the granting of the initial environmental authorization was well-
founded in view of the procedural obligations laid down in the 1975 Stat-
ute. Argentina reiterated this position at the CARU meeting on 6 May
2005. On 12 April 2005, Uruguay had in the meantime authorized the
clearance of the future mill site and the associated groundworks.

40. On 31 May 2005, in pursuance of an agreement made on
5 May 2005 by the Presidents of the two Parties, their Ministers for For-
eign Affairs created a High-Level Technical Group (hereinafter the
“GTAN”, from the Spanish abbreviation for “Grupo Técnico de Alto

Nivel”), which was given responsibility for resolving the disputes over the
CMB (ENCE) and Orion (Botnia) mills within 180 days. The GTAN
held twelve meetings between 3 August 2005 and 30 January 2006, with
the Parties exchanging various documents in the context of this bilateral
process. On 31 January 2006, Uruguay determined that the negotiations

undertaken within the GTAN had failed; Argentina did likewise on
3 February 2006. The Court will return later to the signiﬁcance of this
process agreed on by the Parties (see paragraphs 132 to 149).

41. On 26 June 2005, Argentina wrote to the President of the Interna-

tional Bank for Reconstruction and Development to express its concern
at the possibility of the International Finance Corporation (hereinafter
the “IFC”) contributing to the ﬁnancing of the planned pulp mills. The
IFC nevertheless decided to provide ﬁnancial support for the Orion (Bot-
nia) mill, but did commission EcoMetrix, a consultancy specializing in

environmental and industrial matters, to prepare various technical reports
on the planned mill and an environmental impact assessment of it.
EcoMetrix was also engaged by the IFC to carry out environmental
monitoring on the IFC’s behalf of the plant once it had been placed in
service.
42. On 5 July 2005, Uruguay authorized Botnia to build a port adja-

cent to the Orion (Botnia) mill. This authorization was transmitted to
CARU on 15 August 2005. On 22 August 2005, Uruguay authorized the
construction of a chimney and concrete foundations for the Orion (Bot-
nia) mill. Further authorizations were granted as the construction of this
mill proceeded, for example in respect of the waste treatment installa-

tions. On 13 October 2005, Uruguay transmitted additional documenta-
tion to CARU concerning the port terminal adjacent to the Orion
(Botnia) mill.

28 Argentina repeatedly asked, including at CARU meetings, that the ini-
tial work connected with the Orion (Botnia) mill and the CMB (ENCE)

mill should be suspended. At a meeting between the Heads of State of the
Parties at Santiago de Chile on 11 March 2006, Uruguay’s President
asked ENCE and Botnia to suspend construction of the mills. ENCE sus-
pended work for 90 days (see paragraph 36 above), Botnia for ten.

43. Argentina referred the present dispute to the Court by Application
dated 4 May 2006. On 24 August 2006, Uruguay authorized the commis-
sioning of the port terminal adjacent to the Orion (Botnia) mill and gave
CARU notice of this on 4 September 2006. On 12 September 2006, Uru-

guay authorized Botnia to extract and use water from the river for indus-
trial purposes and formally notiﬁed CARU of its authorization on
17 October 2006. At the summit of Heads of State and Government of
the Ibero-American countries held in Montevideo in November 2006, the
King of Spain was asked to endeavour to reconcile the positions of the
Parties; a negotiated resolution of the dispute did not however result. On

8 November 2007, Uruguay authorized the commissioning of the Orion
(Botnia) mill and it began operating the next day. In December 2009, Oy
Metsä-Botnia AB transferred its interest in the Orion (Botnia) mill to
UPM, another Finnish company.

*

44. In addition, Uruguay authorized Ontur International S.A. to build
and operate a port terminal at Nueva Palmira. The terminal was inaugu-

rated in August 2007 and, on 16 November 2007, Uruguay transmitted to
CARU a copy of the authorization for its commissioning.

45. In their written pleadings the Parties have debated whether, in
light of the procedural obligations laid down in the 1975 Statute, the

authorizations for the port terminal were properly issued by Uruguay.
The Court deems it unnecessary to review the detailed facts leading up to
the construction of the Nueva Palmira terminal, being of the view that
these port facilities do not fall within the scope of the subject of the dis-
pute before it. Indeed, nowhere in the claims asserted in its Application
or in the submissions in its Memorial or Reply (see paragraphs 22 and 23

above) did Argentina explicitly refer to the port terminal at Nueva
Palmira. In its ﬁnal submissions presented at the hearing on 29 Septem-
ber 2009, Argentina again limited the subject-matter of its claims to the
authorization of the construction of the CMB (ENCE) mill and the
authorization of the construction and commissioning of “the Botnia mill

and its associated facilities on the left bank of the River Uruguay”. The
Court does not consider the port terminal at Nueva Palmira, which lies
some 100 km south of Fray Bentos, downstream of the Orion (Botnia)

29mill (see sketch-map No. 1 on p. 33), and is used by other economic

operators as well, to be a facility “associated” with the mill.

46. The dispute submitted to the Court concerns the interpretation
and application of the 1975 Statute, namely, on the one hand whether

Uruguay complied with its procedural obligations under the 1975 Statute
in issuing authorizations for the construction of the CMB (ENCE) mill
as well as for the construction and the commissioning of the Orion (Bot-
nia) mill and its adjacent port; and on the other hand whether Uruguay

has complied with its substantive obligations under the 1975 Statute since
the commissioning of the Orion (Botnia) mill in November 2007.

**

47. Having thus related the circumstances surrounding the dispute
between the Parties, the Court will consider the basis and scope of its
jurisdiction, including questions relating to the law applicable to the

present dispute (see paragraphs 48 to 66). It will then examine Argenti-
na’s allegations of breaches by Uruguay of procedural obligations (see
paragraphs 67 to 158) and substantive obligations (see paragraphs 159 to
266) laid down in the 1975 Statute. Lastly, the Court will respond to the

claims presented by the Parties in their ﬁnal submissions (see para-
graphs 267 to 280).

**

II. SCOPE OF THE C OURT S JURISDICTION

48. The Parties are in agreement that the Court’s jurisdiction is based

on Article 36, paragraph 1, of the Statute of the Court and Article 60,
paragraph 1, of the 1975 Statute. The latter reads: “Any dispute concern-
ing the interpretation or application of the Treaty and the Statute which
cannot be settled by direct negotiations may be submitted by either party

to the International Court of Justice.” The Parties differ as to whether all
the claims advanced by Argentina fall within the ambit of the comprom-
issory clause.

49. Uruguay acknowledges that the Court’s jurisdiction under the
compromissory clause extends to claims concerning any pollution or type
of harm caused to the River Uruguay, or to organisms living there, in
violation of the 1975 Statute. Uruguay also acknowledges that claims

concerning the alleged impact of the operation of the pulp mill on the

1The Montevideo Treaty of 7 April 1961, concerning the boundary constituted by the
River Uruguay (UNTS, Vol. 635, No. 9074, p. 98; footnote added).

30quality of the waters of the river fall within the compromissory clause.
On the other hand, Uruguay takes the position that Argentina cannot

rely on the compromissory clause to submit claims regarding every type
of environmental damage. Uruguay further argues that Argentina’s con-
tentions concerning air pollution, noise, visual and general nuisance, as
well as the speciﬁc impact on the tourism sector, allegedly caused by the
Orion (Botnia) mill, do not concern the interpretation or the application

of the 1975 Statute, and the Court therefore lacks jurisdiction over them.

Uruguay nevertheless does concede that air pollution which has harm-
ful effects on the quality of the waters of the river or on the aquatic envi-
ronment would fall within the jurisdiction of the Court.

50. Argentina maintains that Uruguay’s position on the scope of the
Court’s jurisdiction is too narrow. It contends that the 1975 Statute was
entered into with a view to protect not only the quality of the waters of
the river but more generally its “régime” and the areas affected by it.
Relying on Article 36 of the 1975 Statute, which lays out the obligation
of the parties to co-ordinate measures to avoid any change in the eco-

logical balance and to control harmful factors in the river and the areas
affected by it, Argentina asserts that the Court has jurisdiction also with
respect to claims concerning air pollution and even noise and “visual”
pollution. Moreover, Argentina contends that bad odours caused by the
Orion (Botnia) mill negatively affect the use of the river for recreational

purposes, particularly in the Gualeguaychú resort on its bank of the
river. This claim, according to Argentina, also falls within the Court’s
jurisdiction.
51. The Court, when addressing various allegations or claims advanced
by Argentina, will have to determine whether they concern “the interpre-

tation or application” of the 1975 Statute, as its jurisdiction under Article
60 thereof covers “[a]ny dispute concerning the interpretation or applica-
tion of the [1961] Treaty and the [1975] Statute”. Argentina has made no
claim to the effect that Uruguay violated obligations under the 1961
Treaty.

52. In order to determine whether Uruguay has breached its obliga-
tions under the 1975 Statute, as alleged by Argentina, the Court will have
to interpret its provisions and to determine their scope ratione materiae.

Only those claims advanced by Argentina which are based on the pro-
visions of the 1975 Statute fall within the Court’s jurisdiction ratione

materiae under the compromissory clause contained in Article 60.
Although Argentina, when making claims concerning noise and “visual”
pollution allegedly caused by the pulp mill, invokes the provision of Arti-
cle 36 of the 1975 Statute, the Court sees no basis in it for such claims.
The plain language of Article 36, which provides that “[t]he parties shall

co-ordinate, through the Commission, the necessary measures to avoid
any change in the ecological balance and to control pests and other
harmful factors in the river and the areas affected by it”, leaves no doubt

31that it does not address the alleged noise and visual pollution as claimed
by Argentina. Nor does the Court see any other basis in the 1975 Statute

for such claims; therefore, the claims relating to noise and visual pollu-
tion are manifestly outside the jurisdiction of the Court conferred upon it
under Article 60.

Similarly, no provision of the 1975 Statute addresses the issue of “bad
odours” complained of by Argentina. Consequently, for the same reason,
the claim regarding the impact of bad odours on tourism in Argentina
also falls outside the Court’s jurisdiction. Even if bad odours were to be
subsumed under the issue of air pollution, which will be addressed in

paragraphs 263 and 264 below, the Court notes that Argentina has sub-
mitted no evidence as to any relationship between the alleged bad odours
and the aquatic environment of the river.

53. Characterizing the provisions of Articles 1 and 41 of the 1975 Stat-
ute as “referral clauses”, Argentina ascribes to them the effect of incor-

porating into the Statute the obligations of the Parties under general
international law and a number of multilateral conventions pertaining to
the protection of the environment. Consequently, in the view of Argen-
tina, the Court has jurisdiction to determine whether Uruguay has com-
plied with its obligations under certain international conventions.

54. The Court now therefore turns its attention to the issue whether its
jurisdiction under Article 60 of the 1975 Statute also encompasses obli-
gations of the Parties under international agreements and general inter-
national law invoked by Argentina and to the role of such agreements

and general international law in the context of the present case.

55. Argentina asserts that the 1975 Statute constitutes the law appli-
cable to the dispute before the Court, as supplemented so far as its appli-
cation and interpretation are concerned, by various customary principles

and treaties in force between the Parties and referred to in the Statute.
Relying on the rule of treaty interpretation set out in Article 31, para-
graph 3 (c) of the Vienna Convention on the Law of Treaties, Argentina
contends notably that the 1975 Statute must be interpreted in the light of
principles governing the law of international watercourses and principles
of international law ensuring protection of the environment. It asserts

that the 1975 Statute must be interpreted so as to take account of all “rel-
evant rules” of international law applicable in the relations between the
Parties, so that the Statute’s interpretation remains current and evolves in
accordance with changes in environmental standards. In this connection
Argentina refers to the principles of equitable, reasonable and non-

injurious use of international watercourses, the principles of sustainable
development, prevention, precaution and the need to carry out an envi-
ronmental impact assessment. It contends that these rules and principles

32are applicable in giving the 1975 Statute a dynamic interpretation,
although they neither replace it nor restrict its scope.

56. Argentina further considers that the Court must require compli-
ance with the Parties’ treaty obligations referred to in Articles 1 and
41 (a) of the 1975 Statute. Argentina maintains that the “referral clauses”
contained in these articles make it possible to incorporate and apply obli-
gations arising from other treaties and international agreements binding

on the Parties. To this end, Argentina refers to the 1973 Convention on
International Trade in Endangered Species of Wild Fauna and Flora
(hereinafter the “CITES Convention”), the 1971 Ramsar Convention on
Wetlands of International Importance (hereinafter the “Ramsar Conven-
tion”), the 1992 United Nations Convention on Biological Diversity

(hereinafter the “Biodiversity Convention”), and the 2001 Stockholm
Convention on Persistent Organic Pollutants (hereinafter the “POPs
Convention”). It asserts that these conventional obligations are in addi-
tion to the obligations arising under the 1975 Statute, and observance of
them should be ensured when application of the Statute is being consid-
ered. Argentina maintains that it is only where “more speciﬁc rules of the

[1975] Statute (lex specialis)” derogate from them that the instruments
to which the Statute refers should not be applied.

57. Uruguay likewise considers that the 1975 Statute must be inter-

preted in the light of general international law and it observes that the
Parties concur on this point. It maintains however that its interpretation
of the 1975 Statute accords with the various general principles of the law
of international watercourses and of international environmental law,
even if its understanding of these principles does not entirely correspond

to that of Argentina. Uruguay considers that whether Articles 1 and
41 (a) of the 1975 Statute can be read as a referral to other treaties in
force between the Parties has no bearing in the present case, because con-
ventions relied on by Argentina are either irrelevant, or Uruguay cannot
be found to have violated any other conventional obligations. In any

event, the Court would lack jurisdiction to rule on alleged breaches of
international obligations which are not contained in the 1975 Statute.

58. The Court will ﬁrst address the issue whether Articles 1 and 41 (a)
can be read as incorporating into the 1975 Statute the obligations of the

Parties under the various multilateral conventions relied upon by Argen-
tina.
59. Article 1 of the 1975 Statute reads as follows:

“The parties agree on this Statute, in implementation of the pro-

visions of Article 7 of the Treaty concerning the Boundary Consti-
tuted by the River Uruguay of 7 April 1961, in order to establish the
joint machinery necessary for the optimum and rational utilization

33 of the River Uruguay, in strict observance of the rights and obliga-
tions arising from treaties and other international agreements in

force for each of the parties.” (UNTS, Vol. 1295, No. I-21425,
p. 340; footnote omitted.)

Article 1 sets out the purpose of the 1975 Statute. The Parties con-
cluded it in order to establish the joint machinery necessary for the
rational and optimum utilization of the River Uruguay. It is true that this
article contains a reference to “the rights and obligations arising from

treaties and other international agreements in force for each of the
parties”. This reference, however, does not suggest that the Parties sought
to make compliance with their obligations under other treaties one of
their duties under the 1975 Statute; rather, the reference to other treaties
emphasizes that the agreement of the Parties on the Statute is reached
in implementation of the provisions of Article 7 of the 1961 Treaty

and “in strict observance of the rights and obligations arising from
treaties and other international agreements in force for each of the
parties” (emphasis added). While the conjunction “and” is missing
from the English and French translations of the 1975 Statute, as
published in the United Nations Treaty Series (ibid., p. 340 and p. 348),

it is contained in the Spanish text of the Statute, which is the authentic
text and reads as follows:

“Las partes acuerdan el presente Estatuto, en cumplimiento de lo
dispuesto en el Artículo 7 del Tratado de Límites en el Río Uruguay,
de 7 de Abril de 1961 con el ﬁn de establecer los mecanismos
comunes necesarios para el óptimo y racional aprovechamiento del

Río Uruguay, y en estricta observancia de los derechos y obliga-
ciones emergentes de los tratados y demás compromisos internacion-
ales vigentes para cualquiera de las partes.” (Ibid., p. 332; emphasis
added.)

The presence of the conjunction in the Spanish text suggests that the
clause “in strict observance of the rights and obligations arising from

treaties and other international agreements in force for each of the
parties” is linked to and is to be read with the ﬁrst part of Article 1, i.e.,
“[t]he parties agree on this Statute, in implementation of the provisions of
Article 7 of the Treaty concerning the Boundary Constituted by the
River Uruguay”.
60. There is one additional element in the language of Article 1 of

the 1975 Statute which should be noted. It mentions “treaties and
other international agreements in force for each of the parties” (in
Spanish original “tratados y demás compromisos internacionales vig-
entes para cualquiera de las partes”; emphasis added). In the French
translation, this part of Article 1 reads “traités et autres engagements

internationaux en vigueur à l’égard de l’une ou l’autre des parties”
(emphasis added).
The fact that Article 1 does not require that the “treaties and other

34international agreements” should be in force between the two parties thus
clearly indicates that the 1975 Statute takes account of the prior commit-

ments of each of the parties which have a bearing on it.
61. Article 41 of the 1975 Statute, paragraph (a) of which Argentina
considers as constituting another “referral clause” incorporating the obli-
gations under international agreements into the Statute, reads as follows:

“Without prejudice to the functions assigned to the Commission
in this respect, the parties undertake:

(a) to protect and preserve the aquatic environment and, in par-
ticular, to prevent its pollution, by prescribing appropriate rules
and [adopting appropriate] measures in accordance with appli-
cable international agreements and in keeping, where relevant,

with the guidelines and recommendations of international tech-
nical bodies;
(b) not to reduce in their respective legal systems:
1) the technical requirements in force for preventing water pol-

lution, and
2) the severity of the penalties established for violations;
(c) to inform one another of any rules which they plan to prescribe

with regard to water pollution in order to establish equivalent
rules in their respective legal systems.” (Emphasis added.)

62. The Court observes that the words “adopting appropriate” do not
appear in the English translation while they appear in the original Span-
ish text (“dictando las normas y adoptando las medidas apropiadas”).
Basing itself on the original Spanish text, it is difﬁcult for the Court to see

how this provision could be construed as a “referral clause” having the
effect of incorporating the obligations of the parties under international
agreements and other norms envisaged within the ambit of the 1975
Statute.

The purpose of the provision in Article 41 (a) is to protect and pre-
serve the aquatic environment by requiring each of the parties to enact
rules and to adopt appropriate measures. Article 41 (a) distinguishes
betweenapplicableinternationalagreementsandtheguidelinesandrecom-
mendations of international technical bodies. While the former are legally
binding and therefore the domestic rules and regulations enacted and the

measures adopted by the State have to comply with them, the latter, not
being formally binding, are, to the extent they are relevant, to be taken
into account by the State so that the domestic rules and regulations and
the measures it adopts are compatible (“con adecuación”) with those
guidelines and recommendations. However, Article 41 does not incorpo-

rate international agreements as such into the 1975 Statute but rather sets
obligations for the parties to exercise their regulatory powers, in con-
formity with applicable international agreements, for the protection and

35preservation of the aquatic environment of the River Uruguay. Under
Article 41 (b) the existing requirements for preventing water pollution

and the severity of the penalties are not to be reduced. Finally, para-
graph (c) of Article 41 concerns the obligation to inform the other party
of plans to prescribe rules on water pollution.

63. The Court concludes that there is no basis in the text of Article 41
of the 1975 Statute for the contention that it constitutes a “referral
clause”. Consequently, the various multilateral conventions relied on by
Argentina are not, as such, incorporated in the 1975 Statute. For that

reason, they do not fall within the scope of the compromissory clause and
therefore the Court has no jurisdiction to rule whether Uruguay has com-
plied with its obligations thereunder.

64. The Court next brieﬂy turns to the issue of how the 1975 Statute is
to be interpreted. The Parties concur as to the 1975 Statute’s origin and

historical context, although they differ as to the nature and general tenor
of the Statute and the procedural and substantive obligations therein.

The Parties nevertheless are in agreement that the 1975 Statute is to be
interpreted in accordance with rules of customary international law on

treaty interpretation, as codiﬁed in Article 31 of the Vienna Convention
on the Law of Treaties.
65. The Court has had recourse to these rules when it has had to inter-
pret the provisions of treaties and international agreements concluded
before the entry into force of the Vienna Convention on the Law of Trea-

ties in 1980 (see, e.g., Territorial Dispute (Libyan Arab Jamahiriya/
Chad), Judgment, I.C.J. Reports 1994 , p. 21, para. 41; Kasikili/Sedudu
Island (Botswana/Namibia), Judgment, I.C.J. Reports 1999 (II) , p. 1059,
para. 18).
The 1975 Statute is also a treaty which predates the entry into force of

the Vienna Convention on the Law of Treaties. In interpreting the terms
of the 1975 Statute, the Court will have recourse to the customary rules
on treaty interpretation as reﬂected in Article 31 of the Vienna Conven-
tion. Accordingly the 1975 Statute is to be “interpreted in good faith in
accordance with the ordinary meaning to be given to the terms of the
[Statute] in their context and in light of its object and purpose”. That

interpretation will also take into account, together with the context, “any
relevant rules of international law applicable in the relations between the
parties”.
66. In the interpretation of the 1975 Statute, taking account of rele-
vant rules of international law applicable in the relations between the

Parties, whether these are rules of general international law or contained
in multilateral conventions to which the two States are parties, neverthe-
less has no bearing on the scope of the jurisdiction conferred on the

36Court under Article 60 of the 1975 Statute, which remains conﬁned to

disputes concerning the interpretation or application of the Statute.

**

III. HE A LLEGED BREACH OF PROCEDURAL OBLIGATIONS

67. The Application ﬁled by Argentina on 4 May 2006 concerns the

alleged breach by Uruguay of both procedural and substantive obliga-
tions laid down in the 1975 Statute. The Court will start by considering
the alleged breach of procedural obligations under Articles 7 to 12 of the
1975 Statute, in relation to the (CMB) ENCE and Orion (Botnia) mill

projects and the facilities associated with the latter, on the left bank of
the River Uruguay near the city of Fray Bentos.

68. Argentina takes the view that the procedural obligations were

intrinsically linked to the substantive obligations laid down by the
1975 Statute, and that a breach of the former entailed a breach of the
latter.
With regard to the procedural obligations, these are said by Argentina

to constitute an integrated and indivisible whole in which CARU, as an
organization, plays an essential role.
Consequently, according to Argentina, Uruguay could not invoke
other procedural arrangements so as to derogate from the procedural
obligations laid down by the 1975 Statute, except by mutual consent.

69. Argentina argues that, at the end of the procedural mechanism
provided for by the 1975 Statute, and in the absence of agreement
between the Parties, the latter have no choice but to submit the matter to

the Court under the terms of Articles 12 and 60 of the Statute, with Uru-
guay being unable to proceed with the construction of the planned mills
until the Court has delivered its Judgment.
70. Following the lines of the argument put forward by the Applicant,

the Court will examine in turn the following four points: the links
between the procedural obligations and the substantive obligations (A);
the procedural obligations and their interrelation with each other (B);
whether the Parties agreed to derogate from the procedural obligations

set out in the 1975 Statute (C); and Uruguay’s obligations at the end of
the negotiation period (D).

A. The Links between the Procedural Obligations
and the Substantive Obligations

71. Argentina maintains that the procedural provisions laid down in
Articles 7 to 12 of the 1975 Statute are aimed at ensuring “the optimum

37and rational utilization of the [r]iver” (Article 1), just as are the provi-
sions concerning use of water, the conservation, utilization and develop-

ment of other natural resources, pollution and research. The aim is also
said to be to prevent the Parties from acting unilaterally and without
regard for earlier or current uses of the river. According to Argentina,
any disregarding of this machinery would therefore undermine the object
and purpose of the 1975 Statute; indeed the “optimum and rational

utilization of the [r]iver” would not be ensured, as this could only
be achieved in accordance with the procedures laid down under the
Statute.

72. It follows, according to Argentina, that a breach of the procedural

obligations automatically entails a breach of the substantive obligations,
since the two categories of obligations are indivisible. Such a position is
said to be supported by the Order of the Court of 13 July 2006, according
to which the 1975 Statute created “a comprehensive régime”.

73. Uruguay similarly takes the view that the procedural obligations

are intended to facilitate the performance of the substantive obligations,
the former being a means rather than an end. It too points out that Arti-
cle 1 of the 1975 Statute deﬁnes its object and purpose.

74. However, Uruguay rejects Argentina’s argument as artiﬁcial, since

it appears to mix procedural and substantive questions with the aim of
creating the belief that the breach of procedural obligations necessarily
entails the breach of substantive ones. According to Uruguay, it is for the
Court to determine the breach, in itself, of each of these categories of
obligations, and to draw the necessary conclusions in each case in terms

of responsibility and reparation.

75. The Court notes that the object and purpose of the 1975 Statute,
set forth in Article 1, is for the Parties to achieve “the optimum and
rational utilization of the River Uruguay” by means of the “joint machin-

ery” for co-operation, which consists of both CARU and the procedural
provisions contained in Articles 7 to 12 of the Statute.
The Court has observed in this respect, in its Order of 13 July 2006,
that such use should allow for sustainable development which takes
account of “the need to safeguard the continued conservation of the river
environment and the rights of economic development of the riparian

States” (Pulp Mills on the River Uruguay (Argentina v. Uruguay), Pro-
visional Measures, Order of 13 July 2006, I.C.J. Reports 2006 , p. 133,
para. 80).
76. In the Gabc ˇikovo-Nagymaros case, the Court, after recalling that
“[t]his need to reconcile economic development with protection of the

environment is aptly expressed in the concept of sustainable develop-
ment”, added that “[i]t is for the Parties themselves to ﬁnd an agreed
solution that takes account of the objectives of the Treaty” (Gabc ˇíkovo-

38Nagymaros Project (Hungary/Slovakia), Judgment, I.C.J. Reports 1997 ,
p. 78, paras. 140-141).

77. The Court observes that it is by co-operating that the States con-
cerned can jointly manage the risks of damage to the environment that
might be created by the plans initiated by one or other of them, so as to
prevent the damage in question, through the performance of both the
procedural and the substantive obligations laid down by the 1975 Stat-

ute. However, whereas the substantive obligations are frequently worded
in broad terms, the procedural obligations are narrower and more spe-
ciﬁc, so as to facilitate the implementation of the 1975 Statute through a
process of continuous consultation between the parties concerned. The
Court has described the régime put in place by the 1975 Statute as a

“comprehensive and progressive régime” (Pulp Mills on the River Uru-
guay (Argentina v. Uruguay), Provisional Measures, Order of 13 July
2006, I.C.J. Reports 2006 , p. 133, para. 81), since the two categories of
obligations mentioned above complement one another perfectly, enabling
the parties to achieve the object of the Statute which they set themselves
in Article 1.

78. The Court notes that the 1975 Statute created CARU and estab-
lished procedures in connection with that institution, so as to enable the
parties to fulﬁl their substantive obligations. However, nowhere does the
1975 Statute indicate that a party may fulﬁl its substantive obligations by

complying solely with its procedural obligations, nor that a breach of
procedural obligations automatically entails the breach of substantive
ones.
Likewise, the fact that the parties have complied with their substantive
obligations does not mean that they are deemed to have complied ipso

facto with their procedural obligations, or are excused from doing so.
Moreover, the link between these two categories of obligations can also
be broken, in fact, when a party which has not complied with its proce-
dural obligations subsequently abandons the implementation of its
planned activity.

79. The Court considers, as a result of the above, that there is indeed
a functional link, in regard to prevention, between the two categories of
obligations laid down by the 1975 Statute, but that link does not prevent
the States parties from being required to answer for those obligations
separately, according to their speciﬁc content, and to assume, if neces-
sary, the responsibility resulting from the breach of them, according to

the circumstances.

B. The Procedural Obligations and Their Interrelation

80. The 1975 Statute imposes on a party which is planning certain

activities, set out in Article 7, ﬁrst paragraph, procedural obligations
whose content, interrelation and time-limits are speciﬁed as follows in
Articles 7 to 12:

39 “Article 7

If one party plans to construct new channels, substantially modify
or alter existing ones or carry out any other works which are liable
to affect navigation, the régime of the river or the quality of its
waters, it shall notify the Commission, which shall determine on a

preliminary basis and within a maximum period of 30 days whether
the plan might cause signiﬁcant damage to the other party.

If the Commission ﬁnds this to be the case or if a decision cannot
be reached in that regard, the party concerned shall notify the other

party of the plan through the said Commission.
Such notiﬁcation shall describe the main aspects of the work and,
where appropriate, how it is to be carried out and shall include any
other technical data that will enable the notiﬁed party to assess the
probable impact of such works on navigation, the régime of the river
or the quality of its waters.

Article 8

The notiﬁed party shall have a period of 180 days in which to
respond in connection with the plan, starting from the date on which
its delegation to the Commission receives the notiﬁcation.
Should the documentation referred to in Article 7 be incomplete,
the notiﬁed party shall have 30 days in which to so inform, through

the Commission, the party which plans to carry out the work.

The period of 180 days mentioned above shall begin on the date
on which the delegation of the notiﬁed party receives the full docu-
mentation.

This period may be extended at the discretion of the Commission
if the complexity of the plan so requires.
Article 9

If the notiﬁed party raises no objections or does not respond
within the period established in Article 8, the other party may carry
out or authorize the work planned.

Article 10
The notiﬁed party shall have the right to inspect the works being

carried out in order to determine whether they conform to the plan
submitted.
Article 11

Should the notiﬁed party come to the conclusion that the execu-
tion of the work or the programme of operations might signiﬁcantly
impair navigation, the régime of the river or the quality of its waters,

it shall so notify the other party, through the Commission, within
the period of 180 days established in Article 8.
Such notiﬁcation shall specify which aspects of the work or the

40 programme of operations might signiﬁcantly impair navigation, the
régime of the river or the quality of its waters, the technical reasons

on which this conclusion is based and the changes suggested to the
plan or programme of operations.

Article 12
Should the parties fail to reach agreement within 180 days follow-
ing the notiﬁcation referred to in Article 11, the procedure indicated
in Chapter XV shall be followed.”

81. The original Spanish text of Article 7 of the 1975 Statute reads as
follows:

“La parte que proyecte la construcción de nuevos canales, la
modiﬁcación o alteración signiﬁcativa de los ya existentes o la real-

ización de cualesquiera otras obras de entidad suﬁciente para afectar
la navegación, el régimen del Río o la calidad de sus aguas, deberá
comunicarlo a la Comisión, la cual determinará sumariamente, y en
un plazo máximo de treinta días, si el proyecto puede producir per-
juicio sensible a la otra parte.
Si así se resolviere o no se llegare a una decisión al respecto, la

parte interesada deberá notiﬁcar el proyecto a la otra parte a través
de la misma Comisión.
En la notiﬁcación deberán ﬁgurar los aspectos esenciales de la
obra y, si fuere el caso, el modo de su operación y los demás datos
técnicos que permitan a la parte notiﬁcada hacer una evaluación del

efecto probable que la obra ocasionará a la navegación, al régimen
delRíooalacalidaddesusaguas.”

The Court notes that, just as the original Spanish text, the French
translation of this Article (see paragraph 80 above) distinguishes between
the obligation to inform (“comunicar”) CARU of any plan falling within
its purview (ﬁrst paragraph) and the obligation to notify (“notiﬁcar”) the
other party (second paragraph). By contrast, the English translation uses

the same verb “notify” in respect of both obligations. In order to con-
form to the original Spanish text, the Court will use in both linguistic
versions of this Judgment the verb “inform” for the obligation set out in
the ﬁrst paragraph of Article 7 and the verb “notify” for the obligation
set out in the second and third paragraphs.
The Court considers that the procedural obligations of informing,

notifying and negotiating constitute an appropriate means, accepted by
the Parties, of achieving the objective which they set themselves in Arti-
cle 1 of the 1975 Statute. These obligations are all the more vital when a
shared resource is at issue, as in the case of the River Uruguay, which can
only be protected through close and continuous co-operation between

the riparian States.
82. According to Argentina, by failing to comply with the initial obli-
gation (Article 7, ﬁrst paragraph, of the 1975 Statute) to refer the matter

41to CARU, Uruguay frustrated all the procedures laid down in Articles 7
to 12 of the Statute. In addition, by failing to notify Argentina of the

plans for the CMB (ENCE) and Orion (Botnia) mills, through CARU,
with all the necessary documentation, Uruguay is said not to have com-
plied with Article 7, second and third paragraphs. Argentina adds that
informal contacts which it or CARU may have had with the companies
in question cannot serve as a substitute for Uruguay referring the matter

to CARU and notifying Argentina of the projects through the Commis-
sion. Argentina concludes that Uruguay has breached all of its procedural
obligations under the terms of Articles 7 to 12 of the 1975 Statute.
Uruguay, for its part, considers that referring the matter to CARU
does not impose so great a constraint as Argentina contends and that the

parties may agree, by mutual consent, to use different channels by
employing other procedural arrangements in order to engage in co-
operation. It concludes from this that it has not breached the procedural
obligations laid down by the 1975 Statute, even if it has performed them
without following to the letter the formal process set out therein.
83. The Court will ﬁrst examine the nature and role of CARU, and

then consider whether Uruguay has complied with its obligations to
inform CARU and to notify Argentina of its plans.

1. The nature and role of CARU

84. Uruguay takes the view that CARU, like other river commissions,
is not a body with autonomous powers, but rather a mechanism estab-
lished to facilitate co-operation between the Parties. It adds that the
States which have created these river commissions are free to go outside

the joint mechanism when it suits their purposes, and that they often do
so. According to Uruguay, since CARU is not empowered to act outside
the will of the Parties, the latter are free to do directly what they have
decided to do through the Commission, and in particular may agree not
to inform it in the manner provided for in Article 7 of the 1975 Statute.

Uruguay maintains that that is precisely what happened in the present
case: the two States agreed to dispense with the preliminary review by
CARU and to proceed immediately to direct negotiations.

85. For Argentina, on the other hand, the 1975 Statute is not merely

a bilateral treaty imposing reciprocal obligations on the parties; it
establishes an institutional framework for close and ongoing co-op-
eration, the core and essence of which is CARU. For Argentina,
CARU is the key body for co-ordination between the Parties in virtually
all areas covered by the 1975 Statute. By failing to fulﬁl its obligations

in this respect, Uruguay is said to be calling the 1975 Statute funda-
mentally into question.
86. The Court recalls that it has already described CARU as

42 “a joint mechanism with regulatory, executive, administrative, tech-
nical and conciliatory functions, entrusted with the proper imple-

mentation of the rules contained in the 1975 Statute governing the
management of the shared river resource; . . . [a] mechanism [which]
constitutes a very important part of that treaty régime” (Pulp Mills
on the River Uruguay (Argentina v. Uruguay), Provisional Meas-
ures, Order of 13 July 2006, I.C.J. Reports 2006 , pp. 133-134,

para. 81).

87. The Court notes, ﬁrst, that CARU, in accordance with Article 50
of the 1975 Statute, was endowed with legal personality “in order to per-
form its functions” and that the parties to the 1975 Statute undertook to
provide it with “the necessary resources and all the information and
facilities essential to its operations”. Consequently, far from being merely
a transmission mechanism between the parties, CARU has a permanent

existence of its own; it exercises rights and also bears duties in carrying
out the functions attributed to it by the 1975 Statute.

88. While the decisions of the Commission must be adopted by com-
mon accord between the riparian States (Article 55), these are prepared

and implemented by a secretariat whose staff enjoy privileges and immu-
nities. Moreover, CARU is able to decentralize its various functions by
setting up whatever subsidiary bodies it deems necessary (Article 52).

89. The Court observes that, like any international organization with

legal personality, CARU is entitled to exercise the powers assigned
to it by the 1975 Statute and which are necessary to achieve the
object and purpose of the latter, namely, “the optimum and rational
utilization of the River Uruguay” (Article 1). As the Court has pointed
out,

“[i]nternational organizations are governed by the ‘principle of

speciality’, that is to say, they are invested by the States which
create them with powers, the limits of which are a function of
the common interests whose promotion those States entrust to
them” (Legality of the Use by a State of Nuclear Weapons in
Armed Conﬂict, Advisory Opinion, I.C.J. Reports 1996 (I) ,p .,
para. 25).

This also applies of course to organizations, which like CARU, only have

two member States.
90. Since CARU serves as a framework for consultation between the
parties, particularly in the case of the planned works contemplated in
Article 7, ﬁrst paragraph, of the 1975 Statute, neither of them may depart
from that framework unilaterally, as they see ﬁt, and put other channels

of communication in its place. By creating CARU and investing it with
all the resources necessary for its operation, the parties have sought to
provide the best possible guarantees of stability, continuity and effective-

43ness for their desire to co-operate in ensuring “the optimum and rational
utilization of the River Uruguay”.

91. That is why CARU plays a central role in the 1975 Statute and
cannot be reduced to merely an optional mechanism available to the
parties which each may use or not, as it pleases. CARU operates at all
levels of utilization of the river, whether concerning the prevention of
transboundary harm that may result from planned activities; the use of

water, on which it receives reports from the parties and veriﬁes whether
the developments taken together are liable to cause signiﬁcant damage
(Articles 27 and 28); the avoidance of any change in the ecological bal-
ance (Article 36); scientiﬁc studies and research carried out by one party
within the jurisdiction of the other (Article 44); the exercise of the right

of law enforcement (Article 46); or the right of navigation (Article 48).

92. Furthermore, CARU has been given the function of drawing up
rules in many areas associated with the joint management of the river and
listed in Article 56 of the 1975 Statute. Lastly, at the proposal of either
party, the Commission can act as a conciliation body in any dispute

which may arise between the parties (Article 58).
93. Consequently, the Court considers that, because of the scale and
diversity of the functions they have assigned to CARU, the Parties
intended to make that international organization a central component in
the fulﬁlment of their obligations to co-operate as laid down by the

1975 Statute.

2. Uruguay’s obligation to inform CARU

94. The Court notes that the obligation of the State initiating the

planned activity to inform CARU constitutes the ﬁrst stage in the proce-
dural mechanism as a whole which allows the two parties to achieve the
object of the 1975 Statute, namely, the optimum and rational utilization
of the River Uruguay”. This stage, provided for in Article 7, ﬁrst para-
graph, involves the State which is initiating the planned activity inform-

ing CARU thereof, so that the latter can determine “on a preliminary
basis” and within a maximum period of 30 days whether the plan might
cause signiﬁcant damage to the other party.
95. To enable the remainder of the procedure to take its course, the
parties have included alternative conditions in the 1975 Statute: either
that the activity planned by one party should be liable, in CARU’s

opinion, to cause signiﬁcant damage to the other, creating an obligation
of prevention for the ﬁrst party to eliminate or minimize the risk, in con-
sultation with the other party; or that CARU, having been duly informed,
should not have reached a decision in that regard within the prescribed
period.

96. The Court notes that the Parties are agreed in considering that the
two planned mills were works of sufﬁcient importance to fall within the
scope of Article 7 of the 1975 Statute, and thus for CARU to have been

44informed of them. The same applies to the plan to construct a port ter-
minal at Fray Bentos for the exclusive use of the Orion (Botnia) mill,

which included dredging work and use of the river bed.

97. However, the Court observes that the Parties disagree on whether
there is an obligation to inform CARU in respect of the extraction and
use of water from the river for industrial purposes by the Orion (Botnia)

mill. Argentina takes the view that the authorization granted by the Uru-
guayan Ministry of Transport and Public Works on 12 September 2006
concerns an activity of sufﬁcient importance (“entidad suﬁciente”) to
affect the régime of the river or the quality of its waters and that, in this
matter, Uruguay should have followed the procedure laid down in Arti-

cles 7 to 12 of the 1975 Statute. For its part, Uruguay maintains that this
activity forms an integral part of the Orion (Botnia) mill project as a
whole, and that the 1975 Statute does not require CARU to be informed
of each step in furtherance of the planned works.
98. The Court points out that while the Parties are agreed in recogniz-
ing that CARU should have been informed of the two planned mills and

the plan to construct the port terminal at Fray Bentos, they nonetheless
differ as regards the content of the information which should be provided
to CARU and as to when this should take place.
99. Argentina has argued that the content of the obligation to inform
must be determined in the light of its objective, which is to prevent

threats to navigation, the régime of the river or the quality of the waters.
According to Argentina, the plan which CARU must be informed of may
be at a very early stage, since it is simply a matter of allowing the Com-
mission to “determine on a preliminary basis”, within a very short period
of 30 days, whether the plan “might cause signiﬁcant damage to the other

party”. It is only in the following phase of the procedure that the sub-
stance of the obligation to inform is said to become more extensive. In
Argentina’s view, however, CARU must be informed prior to the authori-
zation or implementation of a project on the River Uruguay.
100. Citing the terms of Article 7, ﬁrst paragraph, of the 1975 Statute,

Uruguay gives a different interpretation of it, taking the view that the
requirement to inform CARU speciﬁed by this provision cannot occur in
the very early stages of planning, because there could not be sufﬁcient
information available to the Commission for it to determine whether or
not the plan might cause signiﬁcant damage to the other State. For that,
according to Uruguay, the project would have to have reached a stage

where all the technical data on it are available. As the Court will consider
further below, Uruguay seeks to link the content of the information to
the time when it should be provided, which may even be after the State
concerned has granted an initial environmental authorization.
101. The Court points out that the principle of prevention, as a cus-

tomary rule, has its origins in the due diligence that is required of a State
in its territory. It is “every State’s obligation not to allow knowingly its
territory to be used for acts contrary to the rights of other States” (Corfu

45Channel (United Kingdom v. Albania), Merits, Judgment, I.C.J. Reports
1949, p. 22). A State is thus obliged to use all the means at its disposal in

order to avoid activities which take place in its territory, or in any area
under its jurisdiction, causing signiﬁcant damage to the environment of
another State. This Court has established that this obligation “is now
part of the corpus of international law relating to the environment”
(Legality of the Threat or Use of Nuclear Weapons, Advisory Opinion,

I.C.J. Reports 1996 (I), p. 242, para. 29).

102. In the view of the Court, the obligation to inform CARU allows
for the initiation of co-operation between the Parties which is necessary
in order to fulﬁl the obligation of prevention. This ﬁrst procedural stage

results in the 1975 Statute not being applied to activities which would
appear to cause damage only to the State in whose territory they are car-
ried out.
103. The Court observes that with regard to the River Uruguay, which
constitutes a shared resource, “signiﬁcant damage to the other party”
(Article 7, ﬁrst paragraph, of the 1975 Statute) may result from impair-

ment of navigation, the régime of the river or the quality of its waters.
Moreover, Article 27 of the 1975 Statute stipulates that:

“[t]he right of each party to use the waters of the river, within its
jurisdiction, for domestic, sanitary, industrial and agricultural pur-
poses shall be exercised without prejudice to the application of the
procedure laid down in Articles 7 to 12 when the use is liable to
affect the régime of the river or the quality of its waters”.

104. The Court notes that, in accordance with the terms of Article 7,

ﬁrst paragraph, the information which must be provided to CARU, at
this initial stage of the procedure, has to enable it to determine swiftly
and on a preliminary basis whether the plan might cause signiﬁcant dam-
age to the other party. For CARU, at this stage, it is a question of decid-
ing whether or not the plan falls under the co-operation procedure laid

down by the 1975 Statute, and not of pronouncing on its actual impact
on the river and the quality of its waters. This explains, in the opinion of
the Court, the difference between the terminology of the ﬁrst paragraph
of Article 7, concerning the requirement to inform CARU, and that of
the third paragraph, concerning the content of the notiﬁcation to be
addressed to the other party at a later stage, enabling it “to assess the

probable impact of such works on navigation, the régime of the river or
the quality of its waters”.
105. The Court considers that the State planning activities referred to
in Article 7 of the Statute is required to inform CARU as soon as it is in
possession of a plan which is sufﬁciently developed to enable CARU to

make the preliminary assessment (required by paragraph 1 of that provi-
sion) of whether the proposed works might cause signiﬁcant damage to
the other party. At that stage, the information provided will not neces-

46sarily consist of a full assessment of the environmental impact of the
project, which will often require further time and resources, although,

where more complete information is available, this should, of course, be
transmitted to CARU to give it the best possible basis on which to make
its preliminary assessment. In any event, the duty to inform CARU will
become applicable at the stage when the relevant authority has had the
project referred to it with the aim of obtaining initial environmental

authorization and before the granting of that authorization.
106. The Court observes that, in the present case, Uruguay did not
transmit to CARU the information required by Article 7, ﬁrst paragraph,
in respect of the CMB (ENCE) and Orion (Botnia) mills, despite the
requests made to it by the Commission to that effect on several occa-

sions, in particular on 17 October 2002 and 21 April 2003 with regard to
the CMB (ENCE) mill, and on 16 November 2004 with regard to the
Orion (Botnia) mill. Uruguay merely sent CARU, on 14 May 2003, a
summary for public release of the environmental impact assessment for
the CMB (ENCE) mill. CARU considered this document to be inad-
equate and again requested further information from Uruguay on

15 August 2003 and 12 September 2003. Moreover, Uruguay did not
transmit any document to CARU regarding the Orion (Botnia) mill.
Consequently, Uruguay issued the initial environmental authorizations
to CMB on 9 October 2003 and to Botnia on 14 February 2005 without
complying with the procedure laid down in Article 7, ﬁrst paragraph.

Uruguay therefore came to a decision on the environmental impact of the
projects without involving CARU, thereby simply giving effect to Arti-
cle 17, third paragraph, of Uruguayan Decree No. 435/994 of 21 Septem-
ber 1994, Environmental Impact Assessment Regulation, according to
which the Ministry of Housing, Land Use Planning and Environmental

Affairs may grant the initial environmental authorization provided that
the adverse environmental impacts of the project remain within accept-
able limits.
107. The Court further notes that on 12 April 2005 Uruguay granted
an authorization to Botnia for the ﬁrst phase of the construction of the

Orion (Botnia) mill and, on 5 July 2005, an authorization to construct
a port terminal for its exclusive use and to utilize the river bed for
industrial purposes, without informing CARU of these projects in
advance.
108. With regard to the extraction and use of water from the river, of
which CARU should have ﬁrst been informed, according to Argentina,

the Court takes the view that this is an activity which forms an integral
part of the commissioning of the Orion (Botnia) mill and therefore did
not require a separate referral to CARU.
109. However, Uruguay maintains that CARU was made aware of the
plans for the mills by representatives of ENCE on 8 July 2002, and no

later than 29 April 2004 by representatives of Botnia, before the initial
environmental authorizations were issued. Argentina, for its part, consid-
ers that these so-called private dealings, whatever form they may have

47taken, do not constitute performance of the obligation imposed on the
Parties by Article 7, ﬁrst paragraph.

110. The Court considers that the information on the plans for the
mills which reached CARU via the companies concerned or from other
non-governmental sources cannot substitute for the obligation to inform
laid down in Article 7, ﬁrst paragraph, of the 1975 Statute, which is
borne by the party planning to construct the works referred to in that

provision. Similarly, in the case concerning Certain Questions of Mutual
Assistance in Criminal Matters (Djibouti v. France), the Court observed
that

“[i]f the information eventually came to Djibouti through the press,
the information disseminated in this way could not be taken into
account for the purposes of the application of Article 17 [of the Con-
vention on Mutual Assistance in Criminal Matters between the two
countries, providing that ‘[r]easons shall be given for any refusal of

mutual assistance’]” (Judgment, I.C.J. Reports 2008 , p. 231,
para. 150).

111. Consequently, the Court concludes from the above that Uruguay,
by not informing CARU of the planned works before the issuing of the
initial environmental authorizations for each of the mills and for the port
terminal adjacent to the Orion (Botnia) mill, has failed to comply with
the obligation imposed on it by Article 7, ﬁrst paragraph, of the 1975 Stat-

ute.

3. Uruguay’s obligation to notify the plans to the other party

112. The Court notes that, under the terms of Article 7, second para-

graph, of the 1975 Statute, if CARU decides that the plan might cause
signiﬁcant damage to the other party or if a decision cannot be reached in
that regard, “the party concerned shall notify the other party of this plan
through the said Commission”.
Article 7, third paragraph, of the 1975 Statute sets out in detail the

content of this notiﬁcation, which
“shall describe the main aspects of the work and . . . any other tech-
nical data that will enable the notiﬁed party to assess the probable

impact of such works on navigation, the régime of the river or the
quality of its waters”.

113. In the opinion of the Court, the obligation to notify is intended to
create the conditions for successful co-operation between the parties, ena-
bling them to assess the plan’s impact on the river on the basis of the
fullest possible information and, if necessary, to negotiate the adjust-
ments needed to avoid the potential damage that it might cause.

114. Article 8 stipulates a period of 180 days, which may be extended
by the Commission, for the notiﬁed party to respond in connection with

48the plan, subject to it requesting the other party, through the Commis-
sion, to supplement as necessary the documentation it has provided.

If the notiﬁed party raises no objections, the other party may carry out
or authorize the work (Article 9). Otherwise, the former must notify the
latter of those aspects of the work which may cause it damage and of the
suggested changes (Article 11), thereby opening a further 180-day period

of negotiation in which to reach an agreement (Article 12).

115. The obligation to notify is therefore an essential part of the proc-
ess leading the parties to consult in order to assess the risks of the plan

and to negotiate possible changes which may eliminate those risks or
minimize their effects.
116. The Parties agree on the need for a full environmental impact
assessment in order to assess any signiﬁcant damage which might be
caused by a plan.
117. Uruguay takes the view that such assessments were carried out in

accordance with its legislation (Decree No. 435/994 of 21 September 1994,
Environmental Impact Assessment Regulation), submitted to DINAMA
for consideration and transmitted to Argentina on 7 November 2003 in
the case of the CMB (ENCE) project and on 19 August 2005 for the
Orion (Botnia) project. According to Uruguay, DINAMA asked the

companies concerned for all the additional information that was required
to supplement the original environmental impact assessments submitted
to it, and only when it was satisﬁed did it propose to the Ministry of the
Environment that the initial environmental authorizations requested
should be issued, which they were to CMB on 9 October 2003 and to

Botnia on 14 February 2005.
Uruguay maintains that it was not required to transmit the environ-
mental impact assessments to Argentina before issuing the initial environ-
mental authorizations to the companies, these authorizations having
been adopted on the basis of its legislation on the subject.

118. Argentina, for its part, ﬁrst points out that the environmental
impact assessments transmitted to it by Uruguay were incomplete, par-
ticularly in that they made no provision for alternative sites for the mills
and failed to include any consultation of the affected populations. The
Court will return later in the Judgment to the substantive conditions
which must be met by environmental impact assessments (see para-

graphs 203 to 219).
Furthermore, in procedural terms, Argentina considers that the initial
environmental authorizations should not have been granted to the com-
panies before it had received the complete environmental impact assess-
ments, and that it was unable to exercise its rights in this context under

Articles 7 to 11 of the 1975 Statute.
119. The Court notes that the environmental impact assessments which
are necessary to reach a decision on any plan that is liable to cause sig-

49niﬁcant transboundary harm to another State must be notiﬁed by the
party concerned to the other party, through CARU, pursuant to Arti-

cle 7, second and third paragraphs, of the 1975 Statute. This notiﬁcation
is intended to enable the notiﬁed party to participate in the process of
ensuring that the assessment is complete, so that it can then consider the
plan and its effects with a full knowledge of the facts (Article 8 of the
1975 Statute).

120. The Court observes that this notiﬁcation must take place before
the State concerned decides on the environmental viability of the plan,
taking due account of the environmental impact assessment submitted to
it.
121. In the present case, the Court observes that the notiﬁcation to

Argentina of the environmental impact assessments for the CMB (ENCE)
and Orion (Botnia) mills did not take place through CARU, and that
Uruguay only transmitted those assessments to Argentina after having
issued the initial environmental authorizations for the two mills in
question. Thus in the case of CMB (ENCE), the matter was notiﬁed to
Argentina on 27 October and 7 November 2003, whereas the initial

environmental authorization had already been issued on 9 October 2003.
In the case of Orion (Botnia), the ﬁle was transmitted to Argentina
between August 2005 and January 2006, whereas the initial environmental
authorization had been granted on 14 February 2005. Uruguay ought
not, prior to notiﬁcation, to have issued the initial environmental auth-

orizations and the authorizations for construction on the basis of the envi-
ronmental impact assessments submitted to DINAMA. Indeed by doing
so, Uruguay gave priority to its own legislation over its procedural
obligations under the 1975 Statute and disregarded the well-established
customary rule reﬂected in Article 27 of the Vienna Convention on the

Law of Treaties, according to which “[a] party may not invoke the pro-
visions of its internal law as justiﬁcation for its failure to perform a
treaty”.

122. The Court concludes from the above that Uruguay failed to

comply with its obligation to notify the plans to Argentina through
CARU under Article 7, second and third paragraphs, of the 1975
Statute.

C. Whether the Parties Agreed to Derogate from the Procedural
Obligations Set Out in the 1975 Statute

123. Having thus examined the procedural obligations laid down by
the 1975 Statute, the Court now turns to the question of whether the
Parties agreed, by mutual consent, to derogate from them, as alleged by
Uruguay.

124. In this respect the Parties refer to two “agreements” reached on
2 March 2004 and 5 May 2005; however, they hold divergent views
regarding their scope and content.

501. The “understanding” of 2 March 2004 between Argentina and
Uruguay

125. The Court recalls that, after the issuing of the initial environmen-
tal authorization to CMB by Uruguay, without CARU having been able
to carry out the functions assigned to it in this context by the 1975 Stat-
ute, the Foreign Ministers of the Parties agreed on 2 March 2004 on the
procedure to be followed, as described in the minutes of the extraordi-

nary meeting of CARU of 15 May 2004. The relevant extract from those
minutes reads as follows in Spanish:

“II) En fecha 2 de marzo de 2004 los Cancilleres de Argentina y
Uruguay llegaron a un entendimiento con relación al curso de
acción que se dará al tema, esto es, facilitar por parte del gobierno
uruguayo, la información relativa a la construcción de la planta y,

en relación a la fase operativa, proceder a realizar el monitoreo, por
parte de CARU, de la calidad de las aguas conforme a su Estatuto.
.............................

I) Ambas delegaciones reaﬁrmaron el compromiso de los Minis-
tros de Relaciones Exteriores de la República Argentina y de la
República Oriental del Uruguay de fecha 2 de marzo de 2004 por el

cual el Uruguay comunicará la información relativa a la construc-
ción de la planta incluyendo el Plan de Gestión Ambiental. En tal
sentido, la CARU recibirá los Planes de Gestión Ambiental para la
construcción y operación de la planta que presente la empresa al
gobierno uruguayo una vez que le sean remitidos por la delegación

uruguaya.” (Emphasis in the original.)
Argentina and Uruguay have provided the Court, respectively, with

French and English translations of these minutes. In view of the discrep-
ancies between those two translations, the Court will use the following
translation:

“(II) On 2 March 2004, the Foreign Ministers of Argentina and
Uruguay reached an understanding on how to proceed in the matter,
namely, that the Uruguayan Government would provide informa-
tion on the construction of the mill and that, in terms of the opera-

tional phase, CARU would carry out monitoring of water quality in
accordance with its Statute.
.............................

(I) Both delegations reafﬁrmed the arrangement which had been
come to by the Foreign Ministers of the Republic of Argentina and
the Eastern Republic of Uruguay on 2 March 2004, whereby Uru-

guay would communicate information on the construction of the
mill, including the environmental management plan. As a result,
CARU would receive the environmental management plans for the

51 construction and operation of the mill provided by the company to
the Uruguayan Government, when these were forwarded to it by the

Uruguayan delegation.” (Emphasis in the original.) [Translation by
the Court.]

126. Uruguay considers that, under the terms of this “understanding”,
the Parties agreed on the approach to be followed in respect of the CMB

(ENCE) project, outside CARU, and that there was no reason in law or
logic to prevent them derogating from the procedures outlined in the
1975 Statute pursuant to an appropriate bilateral agreement.
The said “understanding”, according to Uruguay, only covered the
transmission to CARU of the Environmental Management Plans for the

construction and operation of the (CMB) ENCE mill. It supposedly
thereby puts an end to any dispute with Argentina regarding the proce-
dure laid down in Article 7 of the 1975 Statute. Lastly, Uruguay main-
tains that the “understanding” of 2 March 2004 on the (CMB) ENCE
project was later extended to include the Orion (Botnia) project, since the
PROCEL water quality monitoring plan put in place by CARU’s Sub-

committee on Water Quality to implement that “understanding” related
to the activity of “both plants”, the CMB (ENCE) and Orion (Botnia)
mills, the plural having been used in the title and text of the Subcommit-
tee’s report.
127. Argentina, for its part, maintains that the “understanding”

between the two Ministers of 2 March 2004 was intended to ensure com-
pliance with the procedure laid down by the 1975 Statute and thus to
reintroduce the CMB (ENCE) project within CARU, ending the dispute
on CARU’s jurisdiction to deal with the project. Argentina claims that it
reiterated to the organs within CARU that it had not given up its rights

under Article 7, although it accepted that the dispute between itself and
Uruguay in this respect could have been resolved if the procedure con-
templated in the “understanding” of 2 March 2004 had been brought to
a conclusion.
According to Argentina, however, Uruguay never transmitted the

required information to CARU as it undertook to do in the “understand-
ing” of 2 March 2004. Argentina also denies that the “understanding” of
2 March 2004 was extended to the Orion (Botnia) mill; the reference to
both future plants in the PROCEL plan does not in any way signify, in
its view, the renunciation of the procedure laid down by the 1975 Statute.
128. The Court ﬁrst notes that while the existence of the “understand-

ing” of 2 March 2004, as minuted by CARU, has not been contested by
the Parties, they differ as to its content and scope. Whatever its speciﬁc
designation and in whatever instrument it may have been recorded (the
CARU minutes), this “understanding” is binding on the Parties, to the
extent that they have consented to it and must be observed by them in

good faith. They are entitled to depart from the procedures laid down by
the 1975 Statute, in respect of a given project pursuant to an appropriate
bilateral agreement. The Court recalls that the Parties disagree on whether

52the procedure for communicating information provided for by the “under-
standing” would, if applied, replace that provided for by the 1975 Stat-

ute. Be that as it may, such replacement was dependent on Uruguay
complying with the procedure laid down in the “understanding”.

129. The Court ﬁnds that the information which Uruguay agreed to

transmit to CARU in the “understanding” of 2 March 2004 was never
transmitted. Consequently, the Court cannot accept Uruguay’s conten-
tion that the “understanding” put an end to its dispute with Argentina in
respect of the CMB (ENCE) mill, concerning implementation of the pro-
cedure laid down by Article 7 of the 1975 Statute.

130. Further, the Court observes that, when this “understanding” was
reached, only the CMB (ENCE) project was in question, and that it
therefore cannot be extended to the Orion (Botnia) project, as Uruguay
claims. The reference to both mills is made only as from July 2004, in the
context of the PROCEL plan. However, this plan only concerns the

measures to monitor and control the environmental quality of the river
waters in the areas of the pulp mills, and not the procedures under Article
7 of the 1975 Statute.
131. The Court concludes that the “understanding” of 2 March
2004 would have had the effect of relieving Uruguay of its obligations

under Article 7 of the 1975 Statute, if that was the purpose of the “under-
standing”, only if Uruguay had complied with the terms of the “under-
standing”. In the view of the Court, it did not do so. Therefore the
“understanding” cannot be regarded as having had the effect of exempting
Uruguay from compliance with the procedural obligations laid down by

the 1975 Statute.

2. The agreement setting up the High-Level Technical Group (the
GTAN)

132. The Court notes that, in furtherance of the agreement reached on
5 May 2005 between the Presidents of Argentina and Uruguay (see para-
graph 40 above), the Foreign Ministries of the two States issued a press

release on 31 May 2005 announcing the creation of the High-Level Tech-
nical Group, referred to by the Parties as the GTAN. According to this
communiqué:

“In conformity with what was agreed to by the Presidents of
Argentina and Uruguay, the Foreign Ministries of both of our
countries constitute, under their supervision, a Group of Techni-
cal Experts for complementary studies and analysis, exchange of
information and follow-up on the effects that the operation of the

cellulose plants that are being constructed in the Eastern Republic
of Uruguay will have on the ecosystem of the shared Uruguay
River.

53 This Group . . . is to produce an initial report within a period of
180 days.”

133. Uruguay regards this press release as an agreement that binds the
two States, whereby they decided to make the GTAN the body within
which the direct negotiations between the Parties provided for by
Article 12 of the 1975 Statute would take place, since its purpose was to

analyse the effects on the environment of the “operation of the cellu-
lose plants that are being constructed in the Eastern Republic of Uruguay”.
Uruguay infers from this that the Parties were agreed on the construction
of the mills and that they had limited the extent of the dispute between
them to the environmental risks caused by their operation. Uruguay sees

proof of this in the referral to the Court on the basis of Article 12 of the
1975 Statute, which allows either Party to apply to the Court in the event
of the negotiations failing to produce an agreement within the period of
180 days.
According to Uruguay, therefore, the agreement contained in the press
release of 31 May 2005, by paving the way for the direct negotiations

provided for in Article 12, covered any possible procedural irregularities
in relation to Articles 7 et seq. of the 1975 Statute. Uruguay points out
that it communicated all the necessary information to Argentina during
the 12 meetings held by the GTAN and that it transmitted the Orion
(Botnia) port project to CARU, as agreed by the Parties at the ﬁrst meet-

ing of the GTAN.
134. Uruguay further notes that the 1975 Statute is silent as to whether
the notifying State may or may not implement a project while negotia-
tions are ongoing. It acknowledges that, under international law, the ini-
tiating State must refrain from doing so during the period of negotiation,

but takes the view that this does not apply to all work and, in particular,
that preparatory work is permitted. Uruguay acknowledges that it car-
ried out such work, for example construction of the foundations for the
Orion (Botnia) mill, but in its view this did not involve faits accomplis
which prevented the negotiations from reaching a conclusion. Uruguay

also considers that it had no legal obligation to suspend any and all work
on the port.

135. Argentina considers that no acceptance on its part of the con-
struction of the disputed mills can be inferred from the terms of the press
release of 31 May 2005. It submits that in creating the GTAN, the Parties

did not decide to substitute it for CARU, but regarded it as a means of
negotiation that would co-exist with the latter.

Contrary to Uruguay, Argentina takes the view that this matter has
been submitted to the Court on the basis of Article 60 of the 1975 Statute

and not of Article 12, since Uruguay, by its conduct, has prevented the
latter from being used as a basis, having allegedly disregarded the entire
procedure laid down in Chapter II of the Statute. Argentina therefore

54sees it as for the Court to pronounce on all the breaches of the 1975 Stat-
ute, including and not limited to the authorization for the construction of

the disputed mills.
136. Argentina submits that Uruguay, by its conduct, frustrated the
procedures laid down in Articles 7 to 9 of the 1975 Statute and that, dur-
ing the period of negotiation within the GTAN, Uruguay continued the
construction work on the Orion (Botnia) mill and began building the

port terminal. During that same period, Argentina reiterated, within
CARU, the need for Uruguay to comply with its procedural obligations
under Articles 7 to 12 of the 1975 Statute and to suspend the works.

Lastly, Argentina rejects Uruguay’s claim that the work on the foun-

dations of the Orion (Botnia) mill, its chimney and the port was merely
preliminary in nature and cannot be regarded as the beginning of con-
struction work as such. For Argentina, such a distinction is groundless
and cannot be justiﬁed by the nature of the work carried out.

137. The Court ﬁrst points out that there is no reason to distinguish,

as Uruguay and Argentina have both done for the purpose of their
respective cases, between referral on the basis of Article 12 and of Arti-
cle 60 of the 1975 Statute. While it is true that Article 12 provides for
recourse to the procedure indicated in Chapter XV, should the negotia-
tions fail to produce an agreement within the 180-day period, its purpose

ends there. Article 60 then takes over, in particular its ﬁrst paragraph,
which enables either Party to submit to the Court any dispute concerning
the interpretation or application of the Statute which cannot be settled by
direct negotiations. This wording also covers a dispute relating to the
interpretation or application of Article 12, like any other provision of the

1975 Statute.

138. The Court notes that the press release of 31 May 2005 sets out an
agreement between the two States to create a negotiating framework, the
GTAN, in order to study, analyse and exchange information on the

effects that the operation of the cellulose plants that were being con-
structed in the Eastern Republic of Uruguay could have on the ecosystem
of the shared Uruguay River, with “the group [having] to produce an ini-
tial report within a period of 180 days”.
139. The Court recognizes that the GTAN was created with the aim of
enabling the negotiations provided for in Article 12 of the 1975 Statute,

also for a 180-day period, to take place. Under Article 11, these negotia-
tions between the parties with a view to reaching an agreement are to be
held once the notiﬁed party has sent a communication to the other party,
through the Commission, specifying

“which aspects of the work or the programme of operations might
signiﬁcantly impair navigation, the régime of the river or the quality

55 of its waters, the technical reasons on which this conclusion is based
and the changes suggested to the plan or programme of opera-

tions”.

The Court is aware that the negotiation provided for in Article 12 of
the 1975 Statute forms part of the overall procedure laid down in Articles
7 to 12, which is structured in such a way that the parties, in association

with CARU, are able, at the end of the process, to fulﬁl their obligation
to prevent any signiﬁcant transboundary harm which might be caused by
potentially harmful activities planned by either one of them.

140. The Court therefore considers that the agreement to set up the

GTAN, while indeed creating a negotiating body capable of enabling
the Parties to pursue the same objective as that laid down in Article 12
of the 1975 Statute, cannot be interpreted as expressing the agreement of
the Parties to derogate from other procedural obligations laid down by
the Statute.
141. Consequently, the Court ﬁnds that Argentina, in accepting the

creation of the GTAN, did not give up, as Uruguay claims, the other
procedural rights belonging to it by virtue of the 1975 Statute, nor the
possibility of invoking Uruguay’s responsibility for any breach of those
rights. Argentina did not, in the agreement to set up the GTAN, “effect
a clear and unequivocal waiver” of its rights under the 1975 Statute

(Certain Phosphate Lands in Nauru (Nauru v. Australia), Preliminary
Objections, Judgment, I.C.J. Reports 1992 , p. 247, para. 13). Nor did it
consent to suspending the operation of the procedural provisions of the
1975 Statute. Indeed, under Article 57 of the Vienna Convention on the
Law of Treaties of 23 May 1969, concerning “[s]uspension of the opera-

tion of a treaty”, including, according to the International Law Commis-
sion’s commentary, suspension of “the operation of . . . some of its
provisions” (Yearbook of the International Law Commission , 1966,
Vol. II, p. 251), suspension is only possible “in conformity with the pro-
visions of the treaty” or “by consent of all the parties”.

142. The Court further observes that the agreement to set up the
GTAN, in referring to “the cellulose plants that are being constructed in
the Eastern Republic of Uruguay”, is stating a simple fact and cannot be
interpreted, as Uruguay claims, as an acceptance of their construction by
Argentina.
143. The Court ﬁnds that Uruguay was not entitled, for the duration

of the period of consultation and negotiation provided for in Articles 7 to
12 of the 1975 Statute, either to construct or to authorize the construc-
tion of the planned mills and the port terminal. It would be contrary to
the object and purpose of the 1975 Statute to embark on disputed activi-
ties before having applied the procedures laid down by the “joint machin-

ery necessary for the optimum and rational utilization of the [r]iver”
(Article 1). However, Article 9 provides that: “[i]f the notiﬁed party raises
no objections or does not respond within the period established in Arti-

56cle 8 [180 days], the other party may carry out or authorize the work
planned”.

144. Consequently, in the opinion of the Court, as long as the proce-
dural mechanism for co-operation between the parties to prevent signiﬁ-
cant damage to one of them is taking its course, the State initiating the
planned activity is obliged not to authorize such work and, a fortiori, not
to carry it out.

145. The Court notes, moreover, that the 1975 Statute is perfectly in
keeping with the requirements of international law on the subject, since
the mechanism for co-operation between States is governed by the prin-
ciple of good faith. Indeed, according to customary international law, as
reﬂected in Article 26 of the 1969 Vienna Convention on the Law of

Treaties, “[e]very treaty in force is binding upon the parties to it and must
be performed by them in good faith”. That applies to all obligations
established by a treaty, including procedural obligations which are essen-
tial to co-operation between States. The Court recalled in the cases con-
cerning Nuclear Tests (Australia v. France) (New Zealand v. France):

“One of the basic principles governing the creation and perform-
ance of legal obligations, whatever their source, is the principle of
good faith. Trust and conﬁdence are inherent in international

co-operation . . .” (Judgments, I.C.J. Reports 1974 , p. 268, para. 46,
and p. 473, para. 49; see also Border and Transborder Armed Actions
(Nicaragua v. Honduras), Jurisdiction and Admissibility, Judgment,
I.C.J. Reports 1988, p. 105, para. 94.)

146. The Court has also had occasion to draw attention to the charac-
teristics of the obligation to negotiate and to the conduct which this
imposes on the States concerned: “[the Parties] are under an obligation

so to conduct themselves that the negotiations are meaningful” (North
Sea Continental Shelf (Federal Republic of Germany/Denmark; Federal
Republic of Germany/Netherlands), Judgment, I.C.J. Reports 1969 ,p.47,
para. 85).
147. In the view of the Court, there would be no point to the co-opera-

tion mechanism provided for by Articles 7 to 12 of the 1975 Statute if the
party initiating the planned activity were to authorize or implement it
without waiting for that mechanism to be brought to a conclusion.
Indeed, if that were the case, the negotiations between the parties would
no longer have any purpose.
148. In this respect, contrary to what Uruguay claims, the preliminary

work on the pulp mills on sites approved by Uruguay alone does not con-
stitute an exception. This work does in fact form an integral part of the
construction of the planned mills (see paragraphs 39 and 42 above).

149. The Court concludes from the above that the agreement to set up

the GTAN did not permit Uruguay to derogate from its obligations of
information and notiﬁcation under Article 7 of the 1975 Statute, and that
by authorizing the construction of the mills and the port terminal at

57Fray Bentos before the expiration of the period of negotiation, Uruguay
failed to comply with the obligation to negotiate laid down by Article 12

of the Statute. Consequently, Uruguay disregarded the whole of the
co-operation mechanism provided for in Articles 7 to 12 of the 1975 Statute.
150. Given that “an obligation to negotiate does not imply an obliga-
tion to reach an agreement” (Railway Trafﬁc between Lithuania and
Poland, Advisory Opinion, 1931, P.C.I.J., Series A/B, No. 42 , p. 116), it

remains for the Court to examine whether the State initiating the plan is
under certain obligations following the end of the negotiation period pro-
vided for in Article 12.

D. Uruguay’s Obligations Following the End
of the Negotiation Period

151. Article 12 refers the Parties, should they fail to reach an agree-
ment within 180 days, to the procedure indicated in Chapter XV.

Chapter XV contains a single article, Article 60, according to which:

“Any dispute concerning the interpretation or application of the
Treaty and the Statute which cannot be settled by direct negotiations

may be submitted by either party to the International Court of Jus-
tice.
In the cases referred to in Articles 58 and 59, either party may sub-
mit any dispute concerning the interpretation or application of the
Treaty and the Statute to the International Court of Justice, when it

has not been possible to settle the dispute within 180 days following
the notiﬁcation referred to in Article 59.”

152. According to Uruguay, the 1975 Statute does not give one party
a “right of veto” over the projects initiated by the other. It does not con-
sider there to be a “no construction obligation” borne by the State initi-
ating the projects until such time as the Court has ruled on the dispute.
Uruguay points out that the existence of such an obligation would enable

one party to block a project that was essential for the sustainable devel-
opment of the other, something that would be incompatible with the
“optimum and rational utilization of the [r]iver”. On the contrary, for
Uruguay, in the absence of any speciﬁc provision in the 1975 Statute, ref-
erence should be made to general international law, as reﬂected in the
2001 draft Articles of the International Law Commission on Prevention

of Transboundary Harm from Hazardous Activities (Yearbook of the
International Law Commission , 2001, Vol. II, Part Two); in particular,
draft Article 9, paragraph 3, concerning “Consultations on preventive
measures”, states that “[i]f the consultations . . . fail to produce an agreed
solution, the State of origin shall nevertheless take into account the inter-

ests of the State likely to be affected in case it decides to authorize the
activity to be pursued . . .”.

58 153. Argentina, on the other hand, maintains that Article 12 of the
1975 Statute makes the Court the ﬁnal decision-maker where the parties

have failed to reach agreement within 180 days following the notiﬁcation
referred to in Article 11. It is said to follow from Article 9 of the Statute,
interpreted in the light of Articles 11 and 12 and taking account of its
object and purpose, that if the notiﬁed party raises an objection, the
other party may neither carry out nor authorize the work in question

until the procedure laid down in Articles 7 to 12 has been completed and
the Court has ruled on the project. Argentina therefore considers that,
during the dispute settlement proceedings before the Court, the State
which is envisaging carrying out the work cannot confront the other
Party with the fait accompli of having carried it out.

Argentina argues that the question of the “veto” raised by Uruguay is
inappropriate, since neither of the parties can impose its position in
respect of the construction works and it will ultimately be for the Court
to settle the dispute, if the parties disagree, by a decision that will have
the force of res judicata. It could be said, according to Argentina, that

Uruguay has no choice but to come to an agreement with it or to await
the settlement of the dispute. Argentina contends that, by pursuing the
construction and commissioning of the Orion (Botnia) mill and port,
Uruguay has committed a continuing violation of the procedural obliga-
tions under Chapter II of the 1975 Statute.

154. The Court observes that the “no construction obligation”, said to
be borne by Uruguay between the end of the negotiation period and the
decision of the Court, is not expressly laid down by the 1975 Statute and
does not follow from its provisions. Article 9 only provides for such an
obligation during the performance of the procedure laid down in Arti-

cles 7 to 12 of the Statute.
Furthermore, in the event of disagreement between the parties on the
planned activity persisting at the end of the negotiation period, the Stat-
ute does not provide for the Court, to which the matter would be sub-
mitted by the State concerned, according to Argentina, to decide whether

or not to authorize the activity in question. The Court points out that,
while the 1975 Statute gives it jurisdiction to settle any dispute concern-
ing its interpretation or application, it does not however confer on it the
role of deciding in the last resort whether or not to authorize the planned
activities. Consequently, the State initiating the plan may, at the end of
the negotiation period, proceed with construction at its own risk.

The Court cannot uphold the interpretation of Article 9 according to
which any construction is prohibited until the Court has given its ruling
pursuant to Articles 12 and 60.
155. Article 12 does not impose an obligation on the parties to submit
a matter to the Court, but gives them the possibility of doing so, follow-

ing the end of the negotiation period. Consequently, Article 12 can do
nothing to alter the rights and obligations of the party concerned as long
as the Court has not ruled ﬁnally on them. The Court considers that

59those rights include that of implementing the project, on the sole respon-
sibility of that party, since the period for negotiation has expired.

156. In its Order of 13 July 2006, the Court took the view that the
“construction [of the mills] at the current site cannot be deemed to create
a fait accompli” (Pulp Mills on the River Uruguay (Argentina v. Uru-
guay), Provisional Measures, Order of 13 July 2006, I.C.J. Reports 2006 ,
p. 133, para. 78). Thus, in pronouncing on the merits in the dispute

between the Parties, the Court is the ultimate guarantor of their compli-
ance with the 1975 Statute.
157. The Court concludes from the above that Uruguay did not bear
any “no construction obligation” after the negotiation period provided

for in Article 12 expired on 3 February 2006, the Parties having deter-
mined at that date that the negotiations undertaken within the GTAN
had failed (see paragraph 40). Consequently the wrongful conduct of
Uruguay (established in paragraph 149 above) could not extend beyond
that period.

158. Having established that Uruguay breached its procedural obliga-
tions to inform, notify and negotiate to the extent and for the reasons
given above, the Court will now turn to the question of the compliance of
that State with the substantive obligations laid down by the 1975 Statute.

**

IV. S UBSTANTIVE O BLIGATIONS

159. Before taking up the examination of the alleged violations of
substantive obligations under the 1975 Statute, the Court will address
two preliminary issues, namely, the burden of proof and expert
evidence.

A. Burden of Proof and Expert Evidence

160. Argentina contends that the 1975 Statute adopts an approach in
terms of precaution whereby “the burden of proof will be placed on Uru-

guay for it to establish that the Orion (Botnia) mill will not cause signiﬁ-
cant damage to the environment”. It also argues that the burden of proof
should not be placed on Argentina alone as the Applicant, because, in its
view, the 1975 Statute imposes an equal onus to persuade — for the one
that the plant is innocuous and for the other that it is harmful.

161. Uruguay, on the other hand, asserts that the burden of proof is
on Argentina, as the Applicant, in accordance with the Court’s long-
standing case law, although it considers that, even if the Argentine posi-

tion about transferring the burden of proof to Uruguay were correct, it
would make no difference given the manifest weakness of Argentina’s

60case and the extensive independent evidence put before the Court by
Uruguay. Uruguay also strongly contests Argentina’s argument that the

precautionary approach of the 1975 Statute would imply a reversal of the
burden of proof, in the absence of an explicit treaty provision prescribing
it as well as Argentina’s proposition that the Statute places the burden of
proof equally on both Parties.

162. To begin with, the Court considers that, in accordance with the
well-established principle of onus probandi incumbit actori , it is the duty
of the party which asserts certain facts to establish the existence of such
facts. This principle which has been consistently upheld by the Court

(Maritime Delimitation in the Black Sea (Romania v. Ukraine), Judg-
ment, I.C.J. Reports 2009 , p. 86, para. 68; Sovereignty over Pedra
Branca/Pulau Batu Puteh, Middle Rocks and South Ledge (Malaysia/
Singapore), Judgment, I.C.J. Reports 2008 , p. 31, para. 45; Application
of the Convention on the Prevention and Punishment of the Crime of
Genocide (Bosnia and Herzegovina v. Serbia and Montenegro), Judgment,

I.C.J. Reports 2007 (I), p. 128, para. 204; Military and Paramilitary
Activities in and against Nicaragua (Nicaragua v. United States of
America), Jurisdiction and Admissibility, Judgment, I.C.J. Reports 1984 ,
p. 437, para. 101) applies to the assertions of fact both by the Applicant
and the Respondent.

163. It is of course to be expected that the Applicant should, in the
ﬁrst instance, submit the relevant evidence to substantiate its claims. This
does not, however, mean that the Respondent should not co-operate in
the provision of such evidence as may be in its possession that could assist
the Court in resolving the dispute submitted to it.

164. Regarding the arguments put forward by Argentina on the
reversal of the burden of proof and on the existence, vis-à-vis each Party,
of an equal onus to prove under the 1975 Statute, the Court considers
that while a precautionary approach may be relevant in the interpretation
and application of the provisions of the Statute, it does not follow that it

operates as a reversal of the burden of proof. The Court is also of the
view that there is nothing in the 1975 Statute itself to indicate that it
places the burden of proof equally on both Parties.

*

165. The Court now turns to the issue of expert evidence. Both
Argentina and Uruguay have placed before the Court a vast amount
of factual and scientiﬁc material in support of their respective claims.
They have also submitted reports and studies prepared by the experts

and consultants commissioned by each of them, as well as others
commissioned by the International Finance Corporation in its quality
as lender to the project. Some of these experts have also appeared

61before the Court as counsel for one or the other of the Parties to pro-
vide evidence.

166. The Parties, however, disagree on the authority and reliability of
the studies and reports submitted as part of the record and prepared, on
the one hand, by their respective experts and consultants, and on the
other, by the experts of the IFC, which contain, in many instances, con-
ﬂicting claims and conclusions. In reply to a question put by a judge,

Argentina stated that the weight to be given to such documents should be
determined by reference not only to the “independence” of the author,
who must have no personal interest in the outcome of the dispute and
must not be an employee of the government, but also by reference to the
characteristics of the report itself, in particular the care with which its

analysis was conducted, its completeness, the accuracy of the data used,
and the clarity and coherence of the conclusions drawn from such data.
In its reply to the same question, Uruguay suggested that reports
prepared by retained experts for the purposes of the proceedings
and submitted as part of the record should not be regarded as
independent and should be treated with caution; while expert statements

and evaluations issued by a competent international organization, such
as the IFC, or those issued by the consultants engaged by that
organization should be regarded as independent and given “special weight”.

167. The Court has given most careful attention to the material sub-
mitted to it by the Parties, as will be shown in its consideration of the
evidence below with respect to alleged violations of substantive obliga-
tions. Regarding those experts who appeared before it as counsel at the
hearings, the Court would have found it more useful had they been pre-

sented by the Parties as expert witnesses under Articles 57 and 64 of the
Rules of Court, instead of being included as counsel in their respective
delegations. The Court indeed considers that those persons who provide
evidence before the Court based on their scientiﬁc or technical knowledge
and on their personal experience should testify before the Court as

experts, witnesses or in some cases in both capacities, rather than coun-
sel, so that they may be submitted to questioning by the other party as
well as by the Court.
168. As for the independence of such experts, the Court does not ﬁnd
it necessary in order to adjudicate the present case to enter into a general
discussion on the relative merits, reliability and authority of the docu-

ments and studies prepared by the experts and consultants of the Parties.
It needs only to be mindful of the fact that, despite the volume and com-
plexity of the factual information submitted to it, it is the responsibility
of the Court, after having given careful consideration to all the evidence
placed before it by the Parties, to determine which facts must be consid-

ered relevant, to assess their probative value, and to draw conclusions
from them as appropriate. Thus, in keeping with its practice, the Court
will make its own determination of the facts, on the basis of the evidence

62presented to it, and then it will apply the relevant rules of international
law to those facts which it has found to have existed.

B. Alleged Violations of Substantive Obligations

169. The Court now turns to the examination of the alleged violations
by Uruguay of its substantive obligations under the 1975 Statute by

authorizing the construction and operation of the Orion (Botnia) mill. In
particular, Argentina contends that Uruguay has breached its obligations
under Articles 1, 27, 35, 36 and 41 (a) of the 1975 Statute and “other
obligations deriving from . . . general, conventional and customary inter-
national law which are necessary for the application of the 1975 Statute”.

Uruguay rejects these allegations. Uruguay considers furthermore that
Article 27 of the 1975 Statute allows the parties to use the waters of the
river for domestic, sanitary, industrial and agricultural purposes.

1. The obligation to contribute to the optimum and rational utilization
of the river (Article 1)

170. According to Argentina, Uruguay has breached its obligation to
contribute to the “optimum and rational utilization of the river” by fail-
ing to co-ordinate with Argentina on measures necessary to avoid eco-
logical change, and by failing to take the measures necessary to prevent

pollution. Argentina also maintains that, in interpreting the 1975 Statute
(in particular Articles 27, 35, and 36 thereof) according to the principle of
equitable and reasonable use, account must be taken of all pre-existing
legitimate uses of the river, including in particular its use for recreational
and tourist purposes.

171. For Uruguay, the object and purpose of the 1975 Statute is to
establish a structure for co-operation between the Parties through CARU
in pursuit of the shared goal of equitable and sustainable use of the water
and biological resources of the river. Uruguay contends that it has in no
way breached the principle of equitable and reasonable use of the river

and that this principle provides no basis for favouring pre-existing uses of
the river, such as tourism or ﬁshing, over other, new uses.

172. The Parties also disagree on the scope and implications of Arti-
cle 27 of the 1975 Statute on the right of each Party to use the waters of

the river, within its jurisdiction, for domestic, sanitary, industrial and
agricultural purposes.
173. The Court observes that Article 1, as stated in the title to Chap-
ter I of the 1975 Statute, sets out the purpose of the Statute. As such, it
informs the interpretation of the substantive obligations, but does not by

itself lay down speciﬁc rights and obligations for the parties. Optimum
and rational utilization is to be achieved through compliance with the
obligations prescribed by the 1975 Statute for the protection of the envi-

63ronment and the joint management of this shared resource. This objec-
tive must also be ensured through CARU, which constitutes “the joint

machinery” necessary for its achievement, and through the regulations
adopted by it as well as the regulations and measures adopted by the
Parties.

174. The Court recalls that the Parties concluded the treaty embody-

ing the 1975 Statute, in implementation of Article 7 of the 1961 Treaty,
requiring the Parties jointly to establish a régime for the use of the river
covering, inter alia, provisions for preventing pollution and protecting
and preserving the aquatic environment. Thus, optimum and rational uti-
lization may be viewed as the cornerstone of the system of co-operation

established in the 1975 Statute and the joint machinery set up to imple-
ment this co-operation.
175. The Court considers that the attainment of optimum and rational
utilization requires a balance between the Parties’ rights and needs to use
the river for economic and commercial activities on the one hand, and
the obligation to protect it from any damage to the environment that

may be caused by such activities, on the other. The need for this balance
is reﬂected in various provisions of the 1975 Statute establishing rights
and obligations for the Parties, such as Articles 27, 36, and 41. The Court
will therefore assess the conduct of Uruguay in authorizing the construc-
tion and operation of the Orion (Botnia) mill in the light of those provi-

sions of the 1975 Statute, and the rights and obligations prescribed
therein.
176. The Court has already addressed in paragraphs 84 to 93 above
the role of CARU with respect to the procedural obligations laid down in
the 1975 Statute. In addition to its role in that context, the functions of

CARU relate to almost all aspects of the implementation of the substan-
tive provisions of the 1975 Statute. Of particular relevance in the present
case are its functions relating to rule-making in respect of conservation
and preservation of living resources, the prevention of pollution and its
monitoring, and the co-ordination of actions of the Parties. These func-

tions will be examined by the Court in its analysis of the positions of the
Parties with respect to the interpretation and application of Articles 36
and 41 of the 1975 Statute.

177. Regarding Article 27, it is the view of the Court that its formula-
tion reﬂects not only the need to reconcile the varied interests of riparian

States in a transboundary context and in particular in the use of a shared
natural resource, but also the need to strike a balance between the use of
the waters and the protection of the river consistent with the objective of
sustainable development. The Court has already dealt with the obliga-
tions arising from Articles 7 to 12 of the 1975 Statute which have to be

observed, according to Article 27, by any party wishing to exercise its
right to use the waters of the river for any of the purposes mentioned
therein insofar as such use may be liable to affect the régime of the river

64or the quality of its waters. The Court wishes to add that such utilization
could not be considered to be equitable and reasonable if the interests of

the other riparian State in the shared resource and the environmental
protection of the latter were not taken into account. Consequently, it is
the opinion of the Court that Article 27 embodies this interconnectedness
between equitable and reasonable utilization of a shared resource and the
balance between economic development and environmental protection

that is the essence of sustainable development.

2. The obligation to ensure that the management of the soil and wood-
land does not impair the régime of the river or the quality of its waters

(Article 35)

178. Article 35 of the 1975 Statute provides that the parties:
“undertake to adopt the necessary measures to ensure that the man-

agement of the soil and woodland and the use of groundwater and
the waters of the tributaries of the river do not cause changes which
may signiﬁcantly impair the régime of the river or the quality of its
waters”.

179. Argentina contends that Uruguay’s decision to carry out major
eucalyptus planting operations to supply the raw material for the Orion
(Botnia) mill has an impact on management of the soil and Uruguayan

woodland, but also on the quality of the waters of the river. For its part,
Uruguay states that Argentina does not make any arguments that are
based on Uruguay’s management of soil or woodland — “nor has it
made any allegations concerning the waters of tributaries”.

180. The Court observes that Argentina has not provided any evidence
to support its contention. Moreover, Article 35 concerns the management
of the soil and woodland as well as the use of groundwater and the water
of tributaries, and there is nothing to suggest, in the evidentiary material
submitted by Argentina, a direct relationship between Uruguay’s man-

agement of the soil and woodland, or its use of ground water and water
of tributaries and the alleged changes in the quality of the waters of the
River Uruguay which had been attributed by Argentina to the Orion
(Botnia) mill. Indeed, while Argentina made lengthy arguments about the
effects of the pulp mill discharges on the quality of the waters of the river,
no similar arguments have been presented to the Court regarding a del-

eterious relationship between the quality of the waters of the river and
the eucalyptus-planting operations by Uruguay. The Court concludes
that Argentina has not established its contention on this matter.

3. The obligation to co-ordinate measures to avoid changes in the ecolo-
gical balance (Article 36)

181. Argentina contends that Uruguay has breached Article 36 of the

651975 Statute, which places the Parties under an obligation to co-ordinate
through CARU the necessary measures to avoid changing the ecological

balance of the river. Argentina asserts that the discharges from the Orion
(Botnia) mill altered the ecological balance of the river, and cites as
examples the 4 February 2009 algal bloom, which, according to it, pro-
vides graphic evidence of a change in the ecological balance, as well as
the discharge of toxins, which gave rise, in its view, to the malformed

rotifers whose pictures were shown to the Court.
182. Uruguay considers that any assessment of the Parties’ conduct in
relation to Article 36 of the 1975 Statute must take account of the rules
adopted by CARU, because this Article, creating an obligation of co-op-
eration, refers to such rules and does not by itself prohibit any speciﬁc

conduct. Uruguay takes the position that the mill fully meets CARU
requirements concerning the ecological balance of the river, and con-
cludes that it has not acted in breach of Article 36 of the 1975 Statute.

183. It is recalled that Article 36 provides that “[t]he parties shall co-
ordinate, through the Commission, the necessary measures to avoid any

change in the ecological balance and to control pests and other harmful
factors in the river and the areas affected by it”.
184. It is the opinion of the Court that compliance with this obligation
cannot be expected to come through the individual action of either Party,
acting on its own. Its implementation requires co-ordination through the

Commission. It reﬂects the common interest dimension of the 1975 Stat-
ute and expresses one of the purposes for the establishment of the joint
machinery which is to co-ordinate the actions and measures taken by the
Parties for the sustainable management and environmental protection of
the river. The Parties have indeed adopted such measures through the

promulgation of standards by CARU. These standards are to be found in
Sections E3 and E4 of the CARU Digest. One of the purposes of Sec-
tion E3 is “[t]o protect and preserve the water and its ecological balance”.
Similarly, it is stated in Section E4 that the section was developed “in
accordance with . . . Articles 36, 37, 38, and 39”.

185. In the view of the Court, the purpose of Article 36 of the 1975
Statute is to prevent any transboundary pollution liable to change the
ecological balance of the river by co-ordinating, through CARU, the
adoption of the necessary measures. It thus imposes an obligation on
both States to take positive steps to avoid changes in the ecological

balance. These steps consist not only in the adoption of a regulatory
framework, as has been done by the Parties through CARU, but
also in the observance as well as enforcement by both Parties of
the measures adopted. As the Court emphasized in the Gabc ˇíkovo-
Nagymaros case:

“in the ﬁeld of environmental protection, vigilance and prevention
are required on account of the often irreversible character of damage

66 to the environment and of the limitations inherent in the very
mechanism of reparation of this type of damage” (Gabc ˇíkovo-

Nagymaros Project (Hungary/Slovakia), Judgment, I.C.J. Reports
1997, p. 78, para. 140).

186. The Parties also disagree with respect to the nature of the obliga-
tion laid down in Article 36, and in particular whether it is an obligation
of conduct or of result. Argentina submits that, on a plain meaning,
both Articles 36 and 41 of the 1975 Statute establish an obligation
of result.

187. The Court considers that the obligation laid down in Article 36 is
addressed to both Parties and prescribes the speciﬁc conduct of co-ordi-
nating the necessary measures through the Commission to avoid changes
to the ecological balance. An obligation to adopt regulatory or adminis-
trative measures either individually or jointly and to enforce them is an

obligation of conduct. Both Parties are therefore called upon, under Arti-
cle 36, to exercise due diligence in acting through the Commission for the
necessary measures to preserve the ecological balance of the river.

188. This vigilance and prevention is all the more important in the
preservation of the ecological balance, since the negative impact of
human activities on the waters of the river may affect other components
of the ecosystem of the watercourse such as its ﬂora, fauna, and soil. The

obligation to co-ordinate, through the Commission, the adoption of the
necessary measures, as well as their enforcement and observance, assumes,
in this context, a central role in the overall system of protection of the
River Uruguay established by the 1975 Statute. It is therefore of crucial
importance that the Parties respect this obligation.

189. In light of the above, the Court is of the view that Argentina has
not convincingly demonstrated that Uruguay has refused to engage in
such co-ordination as envisaged by Article 36, in breach of that provi-
sion.

4. The obligation to prevent pollution and preserve the aquatic environ-
ment (Article 41)

190. Article 41 provides that:

“Without prejudice to the functions assigned to the Commission
in this respect, the parties undertake:
(a) to protect and preserve the aquatic environment and, in par-

ticular, to prevent its pollution, by prescribing appropriate
rules and [adopting appropriate] measures in accordance with
applicable international agreements and in keeping, where rele-

67 vant, with the guidelines and recommendations of international
technical bodies;

(b) not to reduce in their respective legal systems:
1. the technical requirements in force for preventing water pol-
lution, and

2. the severity of the penalties established for violations;
(c) to inform one another of any rules which they plan to prescribe
with regard to water pollution in order to establish equivalent
rules in their respective legal systems.”

191. Argentina claims that by allowing the discharge of additional
nutrients into a river that is eutrophic and suffers from reverse ﬂow and

stagnation, Uruguay violated the obligation to prevent pollution, as it
failed to prescribe appropriate measures in relation to the Orion (Botnia)
mill, and failed to meet applicable international environmental agree-
ments, including the Biodiversity Convention and the Ramsar Conven-
tion. It maintains that the 1975 Statute prohibits any pollution which is

prejudicial to the protection and preservation of the aquatic environment
or which alters the ecological balance of the river. Argentina further
argues that the obligation to prevent pollution of the river is an obliga-
tion of result and extends not only to protecting the aquatic environment
proper, but also to any reasonable and legitimate use of the river, includ-
ing tourism and other recreational uses.

192. Uruguay contends that the obligation laid down in Article 41 (a)
of the 1975 Statute to “prevent . . . pollution” does not involve a prohibi-
tion on all discharges into the river. It is only those that exceed the stand-
ards jointly agreed by the Parties within CARU in accordance with their

international obligations, and that therefore have harmful effects, which
can be characterized as “pollution” under Article 40 of the 1975 Statute.
Uruguay also maintains that Article 41 creates an obligation of conduct,
and not of result, but that it actually matters little since Uruguay has
complied with its duty to prevent pollution by requiring the plant to meet

best available technology (“BAT”) standards.

193. Before turning to the analysis of Article 41, the Court recalls
that:

“The existence of the general obligation of States to ensure that
activities within their jurisdiction and control respect the environ-
ment of other States or of areas beyond national control is now part
of the corpus of international law relating to the environment.”

(Legality of the Threat or Use of Nuclear Weapons, Advisory Opin-
ion, I.C.J. Reports 1996 (I) , pp. 241-242, para. 29.)

194. The Court moreover had occasion to stress, in the Gabc ˇíkovo-
Nagymaros Project case, that “the Parties together should look afresh at

68the effects on the environment of the operation of the Gabc ˇíkovo power
plant” (Gabc ˇíkovo-Nagymaros Project (Hungary/Slovakia), Judgment,

I.C.J. Reports 1997, p. 78, para. 140). The Court is mindful of these
statements in taking up now the examination of Article 41 of the
1975 Statute.
195. In view of the central role of this provision in the dispute between
the Parties in the present case and their profound differences as to its

interpretation and application, the Court will make a few remarks of a
general character on the normative content of Article 41 before address-
ing the speciﬁc arguments of the Parties. First, in the view of the Court,
Article 41 makes a clear distinction between regulatory functions
entrusted to CARU under the 1975 Statute, which are dealt with in Arti-

cle 56 of the Statute, and the obligation it imposes on the Parties to adopt
rules and measures individually to “protect and preserve the aquatic envi-
ronment and, in particular, to prevent its pollution”. Thus, the obligation
assumed by the Parties under Article 41, which is distinct from those
under Articles 36 and 56 of the 1975 Statute, is to adopt appropriate rules
and measures within the framework of their respective domestic legal

systems to protect and preserve the aquatic environment and to prevent
pollution. This conclusion is supported by the wording of paragraphs (b)
and (c) of Article 41, which refer to the need not to reduce the technical
requirements and severity of the penalties already in force in the respec-
tive legislation of the Parties as well as the need to inform each other of

the rules to be promulgated so as to establish equivalent rules in their
legal systems.

196. Secondly, it is the opinion of the Court that a simple reading of

the text of Article 41 indicates that it is the rules and measures that are to
be prescribed by the Parties in their respective legal systems which must
be “in accordance with applicable international agreements” and “in
keeping, where relevant, with the guidelines and recommendations of
international technical bodies”.

197. Thirdly, the obligation to “preserve the aquatic environment, and
in particular to prevent pollution by prescribing appropriate rules and
measures” is an obligation to act with due diligence in respect of all
activities which take place under the jurisdiction and control of each
party. It is an obligation which entails not only the adoption of appro-
priate rules and measures, but also a certain level of vigilance in their

enforcement and the exercise of administrative control applicable to pub-
lic and private operators, such as the monitoring of activities undertaken
by such operators, to safeguard the rights of the other party. The
responsibility of a party to the 1975 Statute would therefore be engaged
if it was shown that it had failed to act diligently and thus take all

appropriate measures to enforce its relevant regulations on a public or private
operator under its jurisdiction. The obligation of due diligence
under Article 41 (a) in the adoption and enforcement of appropriate

69rules and measures is further reinforced by the requirement that such
rules and measures must be “in accordance with applicable international

agreements” and “in keeping, where relevant, with the guidelines and
recommendations of international technical bodies”. This requirement
has the advantage of ensuring that the rules and measures adopted
by the parties both have to conform to applicable international agree-
ments and to take account of internationally agreed technical standards.

198. Finally, the scope of the obligation to prevent pollution must
be determined in light of the deﬁnition of pollution given in Article 40

of the 1975 Statute. Article 40 provides that: “For the purposes of this
Statute, pollution shall mean the direct or indirect introduction by
man into the aquatic environment of substances or energy which have
harmful effects.” The term “harmful effects” is deﬁned in the CARU
Digest as:

“any alteration of the water quality that prevents or hinders any
legitimate use of the water, that causes deleterious effects or harm to
living resources, risks to human health, or a threat to water activities

including ﬁshing or reduction of recreational activities” (Title I,
Chapter 1, Section 2, Article 1 (c) of the Digest (E3)).

199. The Digest expresses the will of the Parties and their interpreta-
tion of the provisions of the 1975 Statute. Article 41, not unlike many
other provisions of the 1975 Statute, lays down broad obligations
agreed to by the Parties to regulate and limit their use of the river and

to protect its environment. These broad obligations are given more
speciﬁc content through the co-ordinated rule-making action of
CARU as established under Article 56 of the 1975 Statute or through
the regulatory action of each of the parties, or by both means. The
two regulatory actions are meant to complement each other. As

discussed below (see paragraphs 201 to 202, and 214), CARU standards
concern mainly water quality. The CARU Digest sets only general
limits on certain discharges or efﬂuents from industrial plants such as:
“hydrocarbons”, “sedimentable solids”, and “oils and greases”. As the
Digest makes explicit, those matters are left to each party to regulate.
The Digest provides that, as regards efﬂuents within its jurisdiction,

each party shall take the appropriate “corrective measures” in order
to assure compliance with water quality standards (CARU Digest,
Sec. E3: Pollution, Title 2, Chapter 5, Section 1, Article 3). Uruguay has
taken that action in its Regulation on Water Quality (Decree No. 253/79)
and in relation to the Orion (Botnia) mill in the conditions stipulated in

the authorization issued by MVOTMA. In Argentina, the Entre Ríos
Province, which borders the river opposite the plant, has regulated indus-
trial discharges in a decree that also recognizes the binding effect of the

70CARU Digest (Regulatory Decree No. 5837, Government of Entre Ríos,
26 December 1991, and Regulatory Decree No. 5394, Government

of Entre Ríos, 7 April 1997).

200. The Court considers it appropriate to now address the question

of the rules by which any allegations of breach are to be measured and,
more speciﬁcally, by which the existence of “harmful effects” is to be
determined. It is the view of the Court that these rules are to be found in
the 1975 Statute, in the co-ordinated position of the Parties established
through CARU (as the introductory phrases to Article 41 and Article 56

of the Statute contemplate) and in the regulations adopted by each Party
within the limits prescribed by the 1975 Statute (as paragraphs (a), (b)
and (c) of Article 41 contemplate).

201. The functions of CARU under Article 56 (a) include making
rules governing the prevention of pollution and the conservation

and preservation of living resources. In the exercise of its rule-making
power, the Commission adopted in 1984 the Digest on the uses of the
waters of the River Uruguay and has amended it since. In 1990, when
Section E3 of the Digest was adopted, the Parties recognized that it
was drawn up under Article 7 (f) of the 1961 Treaty and Articles 35,

36, 41 to 45 and 56 (a) (4) of the 1975 Statute. As stated in the
Digest, the “basic purposes” of Section E3 of the Digest are to be as
follows:

“(a) to protect and preserve the water and its ecological balance;

(b) to ensure any legitimate use of the water considering long term

needs and particularly human consumption needs;

(c) to prevent all new forms of pollution and to achieve its reduc-
tion in case the standard values adopted for the different legiti-
mate uses of the River’s water are exceeded;
(d) to promote scientiﬁc research on pollution.” (Title I, Chap-

ter 2, Section 1, Article 1.)
202. The standards laid down in the Digest are not, however, exhaus-

tive. As pointed out earlier, they are to be complemented by the rules and
measures to be adopted by each of the Parties within their domestic laws.

The Court will apply, in addition to the 1975 Statute, these two sets of
rules to determine whether the obligations undertaken by the Parties

have been breached in terms of the discharge of efﬂuent by the mill as
well as in respect of the impact of those discharges on the quality of the
waters of the river, on its ecological balance and on its biodiversity.

71 (a) Environmental Impact Assessment

203. The Court will now turn to the relationship between the need for
an environmental impact assessment, where the planned activity is liable
to cause harm to a shared resource and transboundary harm, and the
obligations of the Parties under Article 41 (a) and (b) of the 1975 Stat-
ute. The Parties agree on the necessity of conducting an environmental

impact assessment. Argentina maintains that the obligations under the
1975 Statute viewed together impose an obligation to conduct an envi-
ronmental impact assessment prior to authorizing Botnia to construct the
plant. Uruguay also accepts that it is under such an obligation. The
Parties disagree, however, with regard to the scope and content of the

environmental impact assessment that Uruguay should have carried out
with respect to the Orion (Botnia) mill project. Argentina maintains in
the ﬁrst place that Uruguay failed to ensure that “full environmental
assessments [had been] produced, prior to its decision to authorize the
construction . . .”; and in the second place that “Uruguay’s decisions
[were] . . . based on unsatisfactory environmental assessments”, in par-

ticular because Uruguay failed to take account of all potential impacts
from the mill, even though international law and practice require it, and
refers in this context to the 1991 Convention on Environmental Impact
Assessment in a Transboundary Context of the United Nations Eco-
nomic Commission for Europe (hereinafter the “Espoo Convention”)

(UNTS, Vol. 1989, p. 309), and the 1987 Goals and Principles of Envi-
ronmental Impact Assessment of the United Nations Environment Pro-
gramme (hereinafter the “UNEP Goals and Principles”) (UNEP/
WG.152/4 Annex (1987), document adopted by UNEP Governing
Council at its 14th Session (Dec. 14/25 (1987)). Uruguay accepts that, in

accordance with international practice, an environmental impact assess-
ment of the Orion (Botnia) mill was necessary, but argues that interna-
tional law does not impose any conditions upon the content of
such an assessment, the preparation of which being a national, not
international, procedure, at least where the project in question is not

one common to several States. According to Uruguay, the only
requirements international law imposes on it are that there must
be assessments of the project’s potential harmful transboundary
effects on people, property and the environment of other States, as
required by State practice and the International Law Commission 2001
draft Articles on Prevention of Transboundary Harm from Hazardous

Activities, without there being any need to assess remote or purely
speculative risks.

204. It is the opinion of the Court that in order for the Parties prop-
erly to comply with their obligations under Article 41 (a) and (b) of the
1975 Statute, they must, for the purposes of protecting and preserving the

72aquatic environment with respect to activities which may be liable to
cause transboundary harm, carry out an environmental impact assess-

ment. As the Court has observed in the case concerning the Dispute
Regarding Navigational and Related Rights ,

“there are situations in which the parties’ intent upon conclusion of
the treaty was, or may be presumed to have been, to give the terms
used — or some of them — a meaning or content capable of evolv-
ing, not one ﬁxed once and for all, so as to make allowance for,
among other things, developments in international law” (Dispute

Regarding Navigational and Related Rights (Costa Rica v. Nicara-
gua), Judgment, I.C.J. Reports 2009 , p. 242, para. 64).

In this sense, the obligation to protect and preserve, under Article 41 (a)
of the Statute, has to be interpreted in accordance with a practice, which
in recent years has gained so much acceptance among States that it may
now be considered a requirement under general international law to
undertake an environmental impact assessment where there is a risk that
the proposed industrial activity may have a signiﬁcant adverse impact in

a transboundary context, in particular, on a shared resource. Moreover,
due diligence, and the duty of vigilance and prevention which it implies,
would not be considered to have been exercised, if a party planning
works liable to affect the régime of the river or the quality of its waters
did not undertake an environmental impact assessment on the potential

effects of such works.

205. The Court observes that neither the 1975 Statute nor general
international law specify the scope and content of an environmental

impact assessment. It points out moreover that Argentina and Uruguay
are not parties to the Espoo Convention. Finally, the Court notes that
the other instrument to which Argentina refers in support of its argu-
ments, namely, the UNEP Goals and Principles, is not binding on the
Parties, but, as guidelines issued by an international technical body, has

to be taken into account by each Party in accordance with Article 41 (a)
in adopting measures within its domestic regulatory framework. More-
over, this instrument provides only that the “environmental effects in an
EIA should be assessed with a degree of detail commensurate with their
likely environmental signiﬁcance” (Principle 5) without giving any indica-
tion of minimum core components of the assessment. Consequently, it is

the view of the Court that it is for each State to determine in its domestic
legislation or in the authorization process for the project, the speciﬁc
content of the environmental impact assessment required in each case,
having regard to the nature and magnitude of the proposed development
and its likely adverse impact on the environment as well as to the need

to exercise due diligence in conducting such an assessment. The Court
also considers that an environmental impact assessment must be
conducted prior to the implementation of a project. Moreover, once

73operations have started and, where necessary, throughout the life of the
project, continuous monitoring of its effects on the environment shall be

undertaken.

206. The Court has already considered the role of the environmental
impact assessment in the context of the procedural obligations of the

Parties under the 1975 Statute (paragraphs 119 and 120). It will now deal
with the speciﬁc points in dispute with regard to the role of this type of
assessment in the fulﬁlment of the substantive obligations of the Parties,
that is to say, ﬁrst, whether such an assessment should have, as a matter
of method, necessarily considered possible alternative sites, taking into

account the receiving capacity of the river in the area where the plant was
to be built and, secondly, whether the populations likely to be affected, in
this case both the Uruguayan and Argentine riparian populations, should
have, or have in fact, been consulted in the context of the environmental
impact assessment.

(i) The siting of the Orion (Botnia) mill at Fray Bentos

207. According to Argentina, one reason why Uruguay’s environmen-
tal impact assessment is inadequate is that it contains no analysis of alter-

natives for the choice of the mill site, whereas the study of alternative
sites is required under international law (UNEP Goals and Principles,
Espoo Convention, IFC Operational Policy 4.01). Argentina contends
that the chosen site is particularly sensitive from an ecological point of
view and unconducive to the dispersion of pollutants “[b]ecause of the

nature of the waters which will receive the pollution, the propensity of
the site to sedimentation and eutrophication, the phenomenon of reverse
ﬂow and the proximity of the largest settlement on the River Uruguay”.

208. Uruguay counters that the Fray Bentos site was initially chosen

because of the particularly large volume of water in the river at that
location, which would serve to promote efﬂuent dilution. Uruguay
adds that the site is moreover easily accessible for river navigation, which
facilitates delivery of raw materials, and local manpower is available
there. Uruguay considers that, if there is an obligation to consider
alternative sites, the instruments invoked for that purpose by Argentina

do not require alternative locations to be considered as part of an
environmental impact assessment unless it is necessary in the circum-
stances to do so. Finally, Uruguay afﬁrms that in any case it did so
and that the suitability of the Orion (Botnia) site was comprehensively
assessed.

209. The Court will now consider, ﬁrst, whether Uruguay failed to
exercise due diligence in conducting the environmental impact assess-
ment, particularly with respect to the choice of the location of the plant

74and, secondly, whether the particular location chosen for the siting of the
plant, in this case Fray Bentos, was unsuitable for the construction of a

plant discharging industrial efﬂuent of this nature and on this scale, or
could have a harmful impact on the river.
210. Regarding the ﬁrst point, the Court has already indicated that the
Espoo Convention is not applicable to the present case (see paragraph 205
above); while with respect to the UNEP Goals and Principles to which

Argentina has referred, whose legal character has been described in para-
graph 205 above, the Court recalls that Principle 4 (c) simply provides
that an environmental impact assessment should include, at a minimum,
“[a] description of practical alternatives, as appropriate”. It is also to be
recalled that Uruguay has repeatedly indicated that the suitability of the

Fray Bentos location was comprehensively assessed and that other pos-
sible sites were considered. The Court further notes that the IFC’s Final
Cumulative Impact Study of September 2006 (hereinafter “CIS”) shows
that in 2003 Botnia evaluated four locations in total at La Paloma, at
Paso de los Toros, at Nueva Palmira, and at Fray Bentos, before choos-
ing Fray Bentos. The evaluations concluded that the limited amount of

fresh water in La Paloma and its importance as a habitat for birds ren-
dered it unsuitable, while for Nueva Palmira its consideration was dis-
couraged by its proximity to residential, recreational, and culturally
important areas, and with respect to Paso de los Toros insufﬁcient ﬂow
of water during the dry season and potential conﬂict with competing

water uses, as well as a lack of infrastructure, led to its exclusion. Con-
sequently, the Court is not convinced by Argentina’s argument that an
assessment of possible sites was not carried out prior to the determina-
tion of the ﬁnal site.

211. Regarding the second point, the Court cannot fail to note that
any decision on the actual location of such a plant along the River Uru-
guay should take into account the capacity of the waters of the river to

receive, dilute and disperse discharges of efﬂuent from a plant of this
nature and scale.
212. The Court notes, with regard to the receiving capacity of the
river at the location of the mill, that the Parties disagree on the geo-
morphological and hydrodynamic characteristics of the river in the
relevant area, particularly as they relate to river ﬂow, and how the

ﬂow of the river, including its direction and its velocity, in turn
determines the dispersal and dilution of pollutants. The differing views
put forward by the Parties with regard to the river ﬂow may be due to
the different modelling systems which each has employed to analyse
the hydrodynamic features of the River Uruguay at the Fray Bentos

location. Argentina implemented a three-dimensional modelling that
measured speed and direction at ten different depths of the river
and used a sonar — an Acoustic Doppler Current Proﬁler (hereafter

75“ADCP”) — to record water ﬂow velocities for a range of depths for
about a year. The three-dimensional system generated a large number of

data later introduced in a numerical hydrodynamic model. On the
other hand, Botnia based its environmental impact assessment on a bi-
dimensional modelling — the RMA2. The EcoMetrix CIS implemented
both three-dimensional and bi-dimensional models. However, it
is not mentioned whether an ADCP sonar was used at different

depths.

213. The Court sees no need to go into a detailed examination of the
scientiﬁc and technical validity of the different kinds of modelling, cali-
bration and validation undertaken by the Parties to characterize the rate

and direction of ﬂow of the waters of the river in the relevant area. The
Court notes however that both Parties agree that reverse ﬂows occur fre-
quently and that phenomena of low ﬂow and stagnation may be observed
in the concerned area, but that they disagree on the implications of this
for the discharges from the Orion (Botnia) mill into this area of the river.

214. The Court considers that in establishing its water quality stand-
ards in accordance with Articles 36 and 56 of the 1975 Statute, CARU
must have taken into account the receiving capacity and sensitivity of the
waters of the river, including in the areas of the river adjacent to Fray
Bentos. Consequently, in so far as it is not established that the discharges

of efﬂuent of the Orion (Botnia) mill have exceeded the limits set by those
standards, in terms of the level of concentrations, the Court ﬁnds itself
unable to conclude that Uruguay has violated its obligations under the
1975 Statute. Moreover, neither of the Parties has argued before the
Court that the water quality standards established by CARU have not

adequately taken into consideration the geomorphological and hydro-
logical characteristics of the river and the capacity of its waters to dis-
perse and dilute different types of discharges. The Court is of the opinion
that, should such inadequacy be detected, particularly with respect to cer-
tain areas of the river such as at Fray Bentos, the Parties should initiate

a review of the water quality standards set by CARU and ensure that
such standards clearly reﬂect the characteristics of the river and are capa-
ble of protecting its waters and its ecosystem.

(ii) Consultation of the affected populations

215. The Parties disagree on the extent to which the populations
likely to be affected by the construction of the Orion (Botnia) mill,
particularly on the Argentine side of the river, were consulted in the
course of the environmental impact assessment. While both Parties
agree that consultation of the affected populations should form part

of an environmental impact assessment, Argentina asserts that inter-
national law imposes speciﬁc obligations on States in this regard.
In support of this argument, Argentina points to Articles 2.6 and 3.8 of

76the Espoo Convention, Article 13 of the 2001 International Law
Commission draft Articles on Prevention of Transboundary Harm

from Hazardous Activities, and Principles 7 and 8 of the UNEP Goals
and Principles. Uruguay considers that the provisions invoked by
Argentina cannot serve as a legal basis for an obligation to consult the
affected populations and adds that in any event the affected populations
had indeed been consulted.

216. The Court is of the view that no legal obligation to consult the
affected populations arises for the Parties from the instruments invoked
by Argentina.
217. Regarding the facts, the Court notes that both before and after

thegrantingoftheinitialenvironmentalauthorization,Uruguaydidunder-
take activities aimed at consulting the affected populations, both on the
Argentine and the Uruguayan sides of the river. These activities included
meetings on 2 December 2003 in Río Negro, and on 26 May 2004 in Fray
Bentos, with participation of Argentine non-governmental organizations.
In addition, on 21 December 2004, a public hearing was convened in

Fray Bentos which, according to Uruguay, addressed among other sub-
jects, the

“handling of chemical products in the plant and in the port; the
appearance of acid rain, dioxins, furans and other polychlorates of
high toxicity that could affect the environment; compliance with the
Stockholm Convention; atmospheric emissions of the plant; electro-
magnetic and electrostatic emissions; [and] liquid discharges into the

river”.

Inhabitants of Fray Bentos and nearby regions of Uruguay and Argen-
tina participated in the meeting and submitted 138 documents containing
questions or concerns.
218. Further, the Court notes that between June and November 2005
more than 80 interviews were conducted by the Consensus Building

Institute, a non-proﬁt organization specializing in facilitated dialogues,
mediation, and negotiation, contracted by the IFC. Such interviews
were conducted inter alia in Fray Bentos, Gualeguaychú, Montevideo,
and Buenos Aires, with interviewees including civil society groups,
non-governmental organizations, business associations, public ofﬁcials,
tourism operators, local business owners, ﬁshermen, farmers and

plantation owners on both sides of the river. In December 2005, the
draft CIS and the report prepared by the Consensus Building
Institute were released, and the IFC opened a period of consultation
to receive additional feedback from stakeholders in Argentina and
Uruguay.

219. In the light of the above, the Court ﬁnds that consultation by
Uruguay of the affected populations did indeed take place.

77 (b) Question of the production technology used in the Orion (Botnia)
mill

220. Argentina maintains that Uruguay has failed to take all measures
to prevent pollution by not requiring the mill to employ the “best avail-
able techniques”, even though this is required under Article 5 (d) of the
POPs Convention, the provisions of which are incorporated by virtue of

the “referral clause” in Article 41 (a) of the 1975 Statute. According to
Argentina, the experts’ reports it cites establish that the mill does not use
best available techniques and that its performance is not up to interna-
tional standards, in the light of the various techniques available for pro-
ducing pulp. Uruguay contests these claims. Relying on the CIS, the

second Hatﬁeld report and the audit conducted by AMEC at the IFC’s
request, Uruguay asserts that the Orion (Botnia) mill is, by virtue of the
technology employed there, one of the best pulp mills in the world,
applying best available techniques and complying with European Union
standards, among others, in the area.

221. Argentina, however, speciﬁcally criticizes the absence of any “ter-
tiary treatment of efﬂuent” (i.e., a third round of processing production
waste before discharge into the natural environment), which is necessary

to reduce the quantity of nutrients, including phosphorus, since the efﬂu-
ent is discharged into a highly sensitive environment. The mill also lacks,
according to Argentina, an empty emergency basin, designed to contain
efﬂuent spills. Answering a question asked by a judge, Argentina consid-
ers that a tertiary treatment would be possible, but that Uruguay failed to

conduct an adequate assessment of tertiary treatment options for the
Orion (Botnia) mill.

222. Uruguay observes that “the experts did not consider it necessary
to equip the mill with a tertiary treatment phase”. Answering the same

question, Uruguay argued that, though feasible, the addition of a tertiary
treatment facility would not be environmentally advantageous overall, as
it would signiﬁcantly increase the energy consumption of the plant, its
carbon emissions, together with sludge generation and chemical use.
Uruguay has consistently maintained that the bleaching technology used
is acceptable, that the emergency basins in place are adequate, that the

mill’s production of synthetic chemical compounds meets technological
requirements and that the potential risk from this production was indeed
assessed.

223. To begin with, the Court observes that the obligation to prevent

pollution and protect and preserve the aquatic environment of the River
Uruguay, laid down in Article 41 (a), and the exercise of due diligence
implied in it, entail a careful consideration of the technology to be used

78by the industrial plant to be established, particularly in a sector such as
pulp manufacturing, which often involves the use or production of sub-

stances which have an impact on the environment. This is all the more
important in view of the fact that Article 41 (a) provides that the regu-
latory framework to be adopted by the Parties has to be in keeping with
the guidelines and recommendations of international technical bodies.

224. The Court notes that the Orion (Botnia) mill uses the bleached
Kraft pulping process. According to the December 2001 Integrated Pol-
lution Prevention and Control Reference Document on Best Available
Techniques in the Pulp and Paper Industry of the European Commission
(hereinafter “IPPC-BAT”), which the Parties referred to as the industry

standard in this sector, the Kraft process already accounted at that time
for about 80 per cent of the world’s pulp production and is therefore the
most applied production method of chemical pulping processes. The
plant employs an ECF-light (Elemental chlorine-free) bleaching process
and a primary and secondary wastewater treatment involving activated
sludge treatment.

225. The Court ﬁnds that, from the point of view of the technology
employed, and based on the documents submitted to it by the Parties,
particularly the IPPC-BAT, there is no evidence to support the claim of
Argentina that the Orion (Botnia) mill is not BAT-compliant in terms of

the discharges of efﬂuent for each tonne of pulp produced. This ﬁnding is
supported by the fact that, as shown below, no clear evidence has been
presented by Argentina establishing that the Orion (Botnia) mill is not in
compliance with the 1975 Statute, the CARU Digest and applicable regu-
lations of the Parties in terms of the concentration of efﬂuents per litre of

wastewater discharged from the plant and the absolute amount of efﬂu-
ents that can be discharged in a day.

226. The Court recalls that Uruguay has submitted extensive data
regarding the monitoring of efﬂuent from the Orion (Botnia) mill, as

contained in the various reports by EcoMetrix and DINAMA
(EcoMetrix, Independent Performance Monitoring as required by the
IFC Phase 2: Six Month Environmental Performance Review (July
2008); EcoMetrix, Independent Performance Monitoring as required
by the IFC, Phase 3: Environmental Performance Review (2008
Monitoring Year) (hereinafter “EcoMetrix Third Monitoring Report”);

DINAMA, Performance Report for the First Year of Operation
of the Botnia Plant and the Environmental Quality of the Area of
Inﬂuence, May 2009; DINAMA, Six Month Report on the Botnia
Emission Control and Environmental Performance Plan), and that
Argentina expressed the view, in this regard, that Uruguay had on this

matter, much greater, if not exclusive, access to the factual evidence. How-
ever, the Court notes that Argentina has itself generated much factual
information and that the materials which Uruguay produced have

79been available to Argentina at various stages of the proceedings or
have been available in the public domain. Therefore the Court does

not consider that Argentina has been at a disadvantage with regard to the
production of evidence relating to the discharges of efﬂuent of the mill.

227. To determine whether the concentrations of pollutants discharged
by the Orion (Botnia) mill are within the regulatory limits, the Court will
have to assess them against the efﬂuent discharge limits — both in terms
of the concentration of efﬂuents in each litre of wastewater discharged
and the absolute amount of efﬂuents that can be discharged in a day —

prescribed by the applicable regulatory standards of the Parties, as char-
acterized by the Court in paragraph 200 above, and the permits issued
for the plant by the Uruguayan authorities, since the Digest only sets
general limits on “hydrocarbons”, “sedimentable solids”, and “oils and
greases”, but does not establish speciﬁc ones for the substances in conten-
tion between the Parties. Argentina did not allege any non-compliance of

the Orion (Botnia) mill with CARU’s efﬂuent standards (CARU Digest,
Sec. E3 (1984, as amended)).

228. Taking into account the data collected after the start-up of the

mill as contained in the various reports by DINAMA and EcoMetrix, it
does not appear that the discharges from the Orion (Botnia) mill have
exceeded the limits set by the efﬂuent standards prescribed by the rele-
vant Uruguayan regulation as characterized by the Court in para-
graph 200 above, or the initial environmental authorization issued by

MVOTMA (MVOTMA, Initial Environmental Authorization for the
Botnia Plant (14 February 2005)), except for a few instances in which the
concentrations have exceeded the limits. The only parameters for which a
recorded measurement exceeded the standards set by Decree No. 253/79
or the initial environmental authorization by MVOTMA are: nitrogen,

nitrates, and AOX (Adsorbable Organic Halogens). In those cases, meas-
urements taken on one day exceeded the threshold. However, the initial
environmental authorization of 14 February 2005 speciﬁcally allows
yearly averaging for the parameters. The most notable of these cases in
which the limits were exceeded is the one relating to AOX, which is the
parameter used internationally to monitor pulp mill efﬂuent, sometimes

including persistent organic pollutants (POPs). According to the IPPC-
BAT reference document submitted by the Parties, and considered
by them as the industry standard in this sector, “the environmental
control authorities in many countries have set severe restrictions on
the discharges of chlorinated organics measured as AOX into the

aquatic environment”. Concentrations of AOX reached at one
point on 9 January 2008, after the mill began operations, as high
a level as 13 mg/L, whereas the maximum limit used in the environ-

80mental impact assessment and subsequently prescribed by MVOTMA was
6 mg/L. However, in the absence of convincing evidence that this is not

an isolated episode but rather a more enduring problem, the Court is not
in a position to conclude that Uruguay has breached the provisions
of the 1975 Statute.

(c) Impact of the discharges on the quality of the waters of the river

229. As pointed out earlier (see paragraph 165), the Parties have over

the last three years presented to the Court a vast amount of factual and
scientiﬁc material containing data and analysis of the baseline levels of
contaminants already present in the river prior to the commissioning of
the plant and the results of measurements of its water and air emissions
after the plant started its production activities and, in some cases, until
mid-2009.

230. Regarding the baseline data, the studies and reports submitted by
the Parties contained data and analysis relating, inter alia, to water qual-
ity, air quality, phytoplankton and zooplankton of the river, health indi-
cators and biomarkers of pollution in ﬁsh from the river, monitoring of
ﬁsh fauna in the area around the Orion (Botnia) mill, ﬁsh community and

species diversity in the river, concentrations of resin acids, chlorinated
phenols and plant sterols in ﬁsh from the river, survey of species belong-
ing to the genus Tillandsia, the Orion (Botnia) mill pre-start-up audit,
and analysis of mercury and lead in ﬁsh muscle.

231. Argentina contends that Uruguay’s baseline data were both inade-
quate and incomplete in many aspects. Uruguay rejects this allegation,
and argues that Argentina has actually relied on Uruguay’s baseline data
to give its own assessment of water quality. According to Uruguay,

contrary to Argentina’s assertions, collection of baseline data by
Uruguay started in August 2006, when DINAMA started to conduct
for a period of 15 months pre-operational water quality monitoring
prior to the commissioning of the plant in November 2007, which
served to complement almost 15 years of more general monitoring
that had been carried out within CARU under the PROCON

programme (River Uruguay Water Quality and Pollution Control
Programme, from the Spanish acronym for “Programa de Calidad
de Aguas y Control de la Contaminación del Río Uruguay”). Argentina
did not challenge counsel for Uruguay’s statement during the oral
proceedings that it used Uruguay’s baseline data for the assessment of

water quality.

232. The data presented by the Parties on the post-operation monitor-

81ing of the actual performance of the plant in terms of the impact of its
emissions on the river includes data obtained through different testing

programmes conducted, inter alia, by an Argentine scientiﬁc team from
two national universities, contracted by the National Secretariat of Envi-
ronment and Sustainable Development of Argentina (ten sites), the OSE
(Uruguay’s State Agency for Sanitary Works, from the Spanish acronym
for “Obras Sanitarias del Estado”), DINAMA, independently of Botnia

(16 sites), and Botnia, reporting to DINAMA and the IFC (four sites;
and testing the efﬂuent).

233. The monitoring sites maintained by Argentina are located on the

Argentine side of the river; with the most upstream position located
10 km from the plant and the furthest downstream one at about 16 km
from the plant. Nevertheless, three of the sites (U0, U2 and U3) are near
the plant; while another three are in Nandubaysal Bay and Inés Lagoon,
the data from which, according to Argentina’s counsel, “enabled the sci-
entists to clearly set the bay apart, as it acts as an ecosystem that is rela-

tively detached from the Uruguay river” (Scientiﬁc and Technical Report,
Chapter 3, appendix: “Background Biogeochemical Studies”, para. 4.1.2;
see also ibid., para. 4.3.1.2).

234. The monitoring sites maintained by Uruguay (DINAMA) and by
Botnia are located on the Uruguayan side. The OSE monitoring point is
located at the drinking water supply intake pipe for Fray Bentos, at or
near DINAMA station 11.
235. Argentina’s team gathered data from November 2007 until

April 2009 with many of the results being obtained from October 2008.
Uruguay, through DINAMA, has been carrying out its monitoring of the
site since March 2006. Its most recent data cover the period up
to June 2009. The OSE, in terms of its overall responsibility for Uru-
guayan water quality, has been gathering relevant data which has been

used in the periodic reports on the operation of the plant.

236. The Court also has before it interpretations of the data provided
by experts appointed by the Parties, and provided by the Parties them-
selves and their counsel. However, in assessing the probative value of the
evidence placed before it, the Court will principally weigh and evaluate

the data, rather than the conﬂicting interpretations given to it by the
Parties or their experts and consultants, in order to determine whether
Uruguay breached its obligations under Articles 36 and 41 of the
1975 Statute in authorizing the construction and operation of the Orion
(Botnia) mill.

237. The particular parameters and substances that are subject to con-
troversy between the Parties in terms of the impact of the discharges of
efﬂuent from the Orion (Botnia) mill on the quality of the waters of the

82river are: dissolved oxygen; total phosphorus (and the related matter of
eutrophication due to phosphate); phenolic substances; nonylphenols

and nonylphenolethoxylates; and dioxins and furans. The Court now
turns to the assessment of the evidence presented to it by the Parties with
respect to these parameters and substances.

(i) Dissolved oxygen

238. Argentina raised for the ﬁrst time during the oral proceedings the
alleged negative impact of the Orion (Botnia) mill on dissolved oxygen in
the river referring to data contained in the report of the Uruguayan OSE.
According to Argentina, since dissolved oxygen is environmentally ben-

eﬁcial and there is a CARU standard which sets a minimum level of dis-
solved oxygen for the river waters (5.6 mg/L), the introduction by the
Orion (Botnia) mill into the aquatic environment of substances or energy
which caused the dissolved oxygen level to fall below that minimum con-
stitutes a breach of the obligation to prevent pollution and to preserve
the aquatic environment. Uruguay argues that Argentina’s ﬁgures taken

from the measurements of the OSE were for “oxidabilidad”, which refers
to the “demand for oxygen” and not for “oxígeno disuelto” — i.e., dis-
solved oxygen. Uruguay also claims that a drop in the level of demand
for oxygen shows an improvement in the quality of the water, since the
level of demand should be kept as low as possible.

239. The Court observes that a post-operational average value of
3.8 mg/L for dissolved oxygen would indeed, if proven, constitute a viola-
tion of CARU standards, since it is below the minimum value of 5.6 mg
of dissolved oxygen per litre required according to the CARU Digest (E3,

Title 2, Chapter 4, Section 2). However, the Court ﬁnds that the allega-
tion made by Argentina remains unproven. First, the ﬁgures on which
Argentina bases itself do not correspond to the ones for dissolved oxygen
that appear in the EcoMetrix Third Monitoring Report, where the sam-
ples taken between February and October 2008 were all above the

CARU minimum standard for dissolved oxygen. Secondly, DINAMA’s
Surface Water and Sediment Quality Data Report of July 2009 (Six
Month Report: January-June) (hereinafter “DINAMA’s Water Quality
Report”) (see p. 7, ﬁg. 4.5: average of 9.4 mg/L) displays concentrations
of dissolved oxygen that are well above the minimum level required
under the CARU Digest. Thirdly, Argentina’s 30 June 2009 report

says in its summary that the records of water quality parameters over
the period were “normal for the river with typical seasonal patterns
of temperature and associated dissolved oxygen”. The hundreds of
measurements presented in the ﬁgures in that chapter of the “Colombo
Report” support that conclusion even taking account of some slightly

lower ﬁgures. Fourthly, the ﬁgures relating to dissolved oxygen
contained in DINAMA’s Water Quality Report have essentially
the same characteristics as those gathered by Argentina — they

83are above the CARU minimum and are the same upstream and down-
stream. Thus, the Court concludes that there appears to be no signiﬁcant

difference between the sets of data over time and that there is no evidence
to support the contention that the reference to “oxidabilidad” in the
OSE report referred to by Argentina should be interpreted to mean “dis-
solved oxygen”.

(ii) Phosphorus

240. There is agreement between the Parties that total phosphorus lev-

els in the River Uruguay are high. According to Uruguay, the total
amount of (natural and anthropogenic) phosphorus emitted into the river
per year is approximately 19,000 tonnes, of which the Orion (Botnia) mill
has a share of some 15 tonnes (in 2008) or even less, as was expected for
2009. These ﬁgures have not been disputed by Argentina during the pro-
ceedings. Uruguay contends further that no violation of the provisions

of the 1975 Statute can be alleged since the high concentration cannot
be clearly attributed to the Orion (Botnia) mill as the source, and since
no standard is set by CARU for phosphorus. Uruguay maintains also
that based on data provided by DINAMA as compared to baseline
data also compiled by DINAMA, it can be demonstrated that “[t]otal

phosphorus levels were generally lower post-start-up as compared
to the 2005-2006 baseline” (EcoMetrix Third Monitoring Report,
March 2009).
241. A major disagreement between the Parties relates to the relation-
ship between the higher concentration of phosphorus in the waters of the

river and the algal bloom of February 2009 and whether operation of the
Orion (Botnia) mill has caused the eutrophication of the river. Argentina
claims that the Orion (Botnia) mill is the cause of the eutrophication and
higher concentration of phosphates, while Uruguay denies the attribut-
ability of these concentrations as well as the eutrophication to the opera-

tion of the plant in Fray Bentos.
242. The Court notes that CARU has not adopted a water quality
standard relating to levels of total phosphorus and phosphates in the
river. Similarly, Argentina has no water quality standards for total phos-
phorus. The Court will therefore have to use the water quality and efﬂu-
ent limits for total phosphorus enacted by Uruguay under its domestic

legislation, as characterized by the Court in paragraph 200 above, to
assess whether the concentration levels of total phosphorus have exceeded
the limits laid down in the regulations of the Parties adopted in accord-
ance with Article 41 (a) of the 1975 Statute. The water quality standard
for total phosphorus under the Uruguayan Regulation is 0.025 mg/L for

certain purposes such as drinking water, irrigation of crops for human
consumption and water used for recreational purposes which involve
direct human contact with the water (Decree No. 253/79, Regulation of

84Water Quality). The Uruguayan Decree also establishes a total phospho-
rus discharge standard of 5 mg/L (Decree No. 253/79 Regulation of

Water Quality, Art. 11 (2)). The Orion (Botnia) mill must comply with
both standards.

243. The Court ﬁnds that based on the evidence before it, the Orion
(Botnia) mill has so far complied with the standard for total phosphorus

in efﬂuent discharge. In this context, the Court notes that, for 2008
according to the EcoMetrix Third Monitoring Report, the Uruguayan
data recorded an average of 0.59 mg/L total phosphorus in efﬂuent dis-
charge from the plant. Moreover, according to the DINAMA 2009 Emis-
sions Report, the efﬂuent ﬁgures for November 2008 to May 2009 were

between 0.053 mg/L and 0.41 mg/L (e.g., DINAMA, “Six Month Report
on the Botnia Emission Control and Environmental Performance Plan
November 11, 2008 to May 31, 2009” (22 July 2009) p. 5; see also pp. 25
and 26). Argentina does not contest these ﬁgures which clearly show val-
ues much below the standard established under the Uruguayan Decree.

244. The Court observes in this connection that as early as 11 Febru-
ary 2005, DINAMA, in its environmental impact assessment for the
Orion (Botnia) mill, noted the heavy load of nutrients (phosphorus and
nitrogen) in the river and stated that:

“This situation has generated the frequent proliferation of algae,

in some cases with an important degree of toxicity as a result of the
proliferation of cyanobacteria. These proliferations, which in recent
years have shown an increase in both frequency and intensity, con-
stitute a health risk and result in important economic losses since
they interfere with some uses of water, such as recreational activities

and the public supply of drinking water. To this already existing
situation it must be added that, in the future, the efﬂuent in the plant
will emit a total of 200 t/a of N[itrogen] and 20 t/a of P[hosphorus],
values that are the approximate equivalent of the emission of the un-
treated sewage of a city of 65,000 people.” (P. 20, para. 6.1.)

245. The DINAMA Report then continues as follows:

“It is also understood that it is not appropriate to authorize any

waste disposal that would increase any of the parameters that present
critical values, even in cases in which the increase is considered insig-
niﬁcant by the company. Nevertheless, considering that the para-
meters in which the quality of water is compromised are not speciﬁc
to the efﬂuents of this project, but rather would be affected by the

waste disposal of any industrial or domestic efﬂuent under consid-
eration, it is understood that the waste disposal proposed in the
project may be accepted, as long as there is compensation for any

85 increase over and above the standard value for any of the critical
parameters.” (DINAMA Report, p. 21.)

246. The Court further notes that the initial environmental authoriza-
tion, granted on 15 February 2005, required compliance by Botnia with
those conditions, with CARU standards and with best available tech-
niques as included in the December 2001 IPPC-BAT of the European

Commission. It also required the completion of an implementation plan
for mitigation and compensation measures. That plan was completed by
the end of 2007 and the authorization to operate was granted on 8 Novem-
ber 2007. On 29 April 2008, Botnia and the OSE concluded an Agree-
ment Regarding Treatment of the Municipal Wastewater of Fray Bentos,

aimed at reducing total phosphorus and other contaminants.

247. The Court considers that the amount of total phosphorus dis-
charge into the river that may be attributed to the Orion (Botnia) mill is
insigniﬁcant in proportionate terms as compared to the overall total
phosphorus in the river from other sources. Consequently, the Court

concludes that the fact that the level of concentration of total phosphorus
in the river exceeds the limits established in Uruguayan legislation in
respect of water quality standards cannot be considered as a violation of
Article 41 (a) of the 1975 Statute in view of the river’s relatively high
total phosphorus content prior to the commissioning of the plant, and

taking into account the action being taken by Uruguay by way of com-
pensation.
248. The Court will now turn to the consideration of the issue of the
algal bloom of 4 February 2009. Argentina claims that the algal bloom of
4 February 2009 was caused by the Orion (Botnia) mill’s emissions of

nutrients into the river. To substantiate this claim Argentina points to the
presence of efﬂuent products in the blue-green algal bloom and to vari-
ous satellite images showing the concentration of chlorophyll in the
water. Such blooms, according to Argentina, are produced during the
warm season by the explosive growth of algae, particularly cyanobact-

eria, responding to nutrient enrichment, mainly phosphate, among other
compounds present in detergents and fertilizers.
249. Uruguay contends that the algal bloom of February 2009, and
the high concentration of chlorophyll, was not caused by the Orion (Bot-
nia) mill but could have originated far upstream and may have most
likely been caused by the increase of people present in Gualeyguaychú

during the yearly carnival held in that town, and the resulting increase in
sewage, and not by the mill’s efﬂuents. Uruguay maintains that Argen-
tine data actually prove that the Orion (Botnia) mill has not added to the
concentration of phosphorus in the river at any time since it began
operating.

250. The Parties are in agreement on several points regarding the algal
bloom of 4 February 2009, including the fact that the concentrations of

86nutrients in the River Uruguay have been at high levels both before and
after the bloom episode, and the fact that the bloom disappeared shortly

after it had begun. The Parties also appear to agree on the interdepend-
ence between algae growth, higher temperatures, low and reverse ﬂows,
and presence of high levels of nutrients such as nitrogen and phosphorus
in the river. It has not, however, been established to the satisfaction of
the Court that the algal bloom episode of 4 February 2009 was caused by

the nutrient discharges from the Orion (Botnia) mill.

(iii) Phenolic substances

251. With regard to phenolic substances, Argentina contends that the
Orion (Botnia) mill’s emission of pollutants have resulted in violations of
the CARU standard for phenolic substances once the plant started oper-
ating, while, according to Argentina, pre-operational baseline data did
not show that standard to have been exceeded. Uruguay on the other
hand argues that there have been numerous violations of the standard,

throughout the river, long before the plant went into operation. Uruguay
substantiates its arguments by pointing to several studies including the
EcoMetrix ﬁnal Cumulative Impact Study, which had concluded that
phenolic substances were found to have frequently exceeded the water
quality standard of 0.001 mg/L ﬁxed by CARU.

252. The Court also notes that Uruguayan data indicate that the water
quality standard was being exceeded from long before the plant began
operating. The Cumulative Impact Study prepared in September 2006 by
EcoMetrix for the IFC states that phenolics were found frequently to
exceed the standard, with the highest values on the Argentine side of the

river. The standard is still exceeded in some of the measurements in the
most recent report before the Court but most are below it (DINAMA
July 2009 Water Quality Report, p. 21, para. 4.1.11.2 and App. 1, show-
ing measurements from 0.0005 to 0.012 mg/L).

253. During the oral proceedings, counsel for Argentina claimed that
the standard had not previously been exceeded and that the plant has
caused the limit to be exceeded. The concentrations, he said, had increased
on average by three times and the highest ﬁgure was 20 times higher.

Uruguay contends that the data contained in the DINAMA 2009 Report
shows that the post-operational levels of phenolic substances were lower
than the baseline levels throughout the river including at the OSE water
intake.

254. Based on the record, and the data presented by the Parties, the
Court concludes that there is insufﬁcient evidence to attribute the alleged

87increase in the level of concentrations of phenolic substances in the river
to the operations of the Orion (Botnia) mill.

(iv) Presence of nonylphenols in the river environment

255. Argentina claims that the Orion (Botnia) mill emits, or has emit-
ted, nonylphenols and thus has caused damage to, or at least has sub-

stantially put at risk, the river environment. According to Argentina, the
most likely source of these emissions are surfactants (detergents), nonyl-
phenolethoxylates used to clean the wood pulp as well as the installations
of the plant itself. Argentina also contends that from 46 measurements
performed in water samples the highest concentrations, in particular

those exceeding the European Union relevant standards, were deter-
mined in front-downstream the mill and in the bloom sample collected on
4 February 2009, with lower levels upstream and downstream, indicating
that the Orion (Botnia) mill efﬂuent is the most probable source of these
residues. In addition, according to Argentina, bottom sediments collected
in front-downstream the mill showed a rapid increase of nonylphenols

from September 2006 to February 2009, corroborating the increasing
trend of these compounds in the River Uruguay. For Argentina, the spatial
distribution of sub-lethal effects detected in rotifers (absence of
spines), transplanted Asiatic clams (reduction of lipid reserves) and ﬁsh
(estrogenic effects) coincided with the distribution area of nonylphenols

suggesting that these compounds may be a signiﬁcant stress factor.

256. Uruguay rejects Argentina’s claim relating to nonylphenols and
nonylphenolethoxylates, and categorically denies the use of nonylphenols
and nonylphenolethoxylates by the Orion (Botnia) mill. In particular, it
provides afﬁdavits from Botnia ofﬁcials to the effect that the mill does
not use and has never used nonylphenols or nonylphenolethoxylate

derivatives in any of its processes for the production of pulp, including in
the pulp washing and cleaning stages, and that no cleaning agents con-
taining nonylphenols are or have been used for cleaning the plant’s
equipment (Afﬁdavit of Mr. González, 2 October 2009).

257. The Court recalls that the issue of nonylphenols was included in

the record of the case before the Court only by the Report submitted by
Argentina on 30 June 2009. Although testing for nonylphenols had been
carried out since November 2008, Argentina has not however, in the
view of the Court, adduced clear evidence which establishes a link
between the nonylphenols found in the waters of the river and the Orion

(Botnia) mill. Uruguay has also categorically denied before the Court
the use of nonylphenolethoxylates for production or cleaning by the
Orion (Botnia) mill. The Court therefore concludes that the evidence in

88the record does not substantiate the claims made by Argentina on this
matter.

(v) Dioxins and furans

258. Argentina has alleged that while the concentration of dioxins and
furans in surface sediments is generally very low, data from its studies

demonstrated an increasing trend compared to data compiled before the
Orion (Botnia) mill commenced operations. Argentina does not claim a
violation of standards, but relies on a sample of sábalo ﬁsh tested by its
monitoring team, which showed that one ﬁsh presented elevated levels of
dioxins and furans which, according to Argentina, pointed to a rise in the

incidence of dioxins and furans in the river after the commissioning
of the Orion (Botnia) mill. Uruguay contests this claim, arguing that
such elevated levels cannot be linked to the operation of the Orion
(Botnia) mill, given the presence of so many other industries operating
along the River Uruguay and in neighbouring Nandubaysal Bay, and

the highly migratory nature of the sábalo species which was tested.
In addition, Uruguay advances that its testing of the efﬂuent coming
from the Orion (Botnia) mill demonstrate that no dioxins and furans
could have been introduced into the mill efﬂuent, as the levels detected
in the efﬂuent were not measurably higher than the baseline levels in

the River Uruguay.

259. The Court considers that there is no clear evidence to link the
increase in the presence of dioxins and furans in the river to the operation
of the Orion (Botnia) mill.

(d) Effects on biodiversity

260. Argentina asserts that Uruguay “has failed to take all measures
to protect and preserve the biological diversity of the River Uruguay and
the areas affected by it”. According to Argentina, the treaty obligation

“to protect and preserve the aquatic environment” comprises an obliga-
tion to protect the biological diversity including “habitats as well as species
of ﬂora and fauna”. By virtue of the “referral clause” in Article
41 (a), Argentina argues that the 1975 Statute requires Uruguay, in
respect of activities undertaken in the river and areas affected by it, to
comply with the obligations deriving from the CITES Convention, the

Biodiversity Convention and the Ramsar Convention. Argentina main-
tains that through its monitoring programme abnormal effects were
detected in aquatic organisms — such as malformation of rotifers and
loss of fat by clams — and the biomagniﬁcation of persistent pollutants
such as dioxins and furans was detected in detritus feeding ﬁsh (such as

the sábalo ﬁsh). Argentina also contends that the operation of the mill
poses a threat, under conditions of reverse ﬂow, to the Esteros de Farra-
pos site, situated “in the lower section of the River . . . downstream from

89the Salto Grande dam and on the frontier with Argentina”, a few kilo-
metres upstream from the Orion (Botnia) mill.

261. Uruguay states that Argentina has failed to demonstrate any
breach by Uruguay of the Biodiversity Convention, while the Ramsar
Convention has no bearing in the present case because Esteros de Farra-

pos was not included in the list of Ramsar sites whose ecological charac-
ter is threatened. With regard to the possibility of the efﬂuent plume from
the mill reaching Esteros de Farrapos, Uruguay in the oral proceedings
acknowledged that under certain conditions that might occur. However,
Uruguay added that it would be expected that the dilution of the efﬂuent

from the mill of 1:1000 would render the efﬂuent quite harmless
and below any concentration capable of constituting pollution. Uruguay
contends that Argentina’s claims regarding the harmful effects on ﬁsh
and rotifers as a result of the efﬂuents from the Orion (Botnia) mill
are not credible. It points out that a recent comprehensive report of
DINAMA on ichthyofauna concludes that compared to 2008 and

2009 there has been no change in species biodiversity. Uruguay adds
that the July 2009 report of DINAMA, with results of its February 2009
monitoring of the sediments in the river where some ﬁsh species feed,
stated that “the quality of the sediments at the bottom of the Uruguay
River has not been altered as a consequence of the industrial activity

of the Botnia plant”.

262. The Court is of the opinion that as part of their obligation to pre-
serve the aquatic environment, the Parties have a duty to protect the
fauna and ﬂora of the river. The rules and measures which they have to

adopt under Article 41 should also reﬂect their international under-
takings in respect of biodiversity and habitat protection, in addition to
the other standards on water quality and discharges of efﬂuent. The
Court has not, however, found sufﬁcient evidence to conclude that Uru-
guay breached its obligation to preserve the aquatic environment includ-

ing the protection of its fauna and ﬂora. The record rather shows that a
clear relationship has not been established between the discharges from
the Orion (Botnia) mill and the malformations of rotifers, or the dioxin
found in the sábalo ﬁsh or the loss of fat by clams reported in the ﬁndings
of the Argentine River Uruguay Environmental Surveillance (URES)
programme.

(e) Air pollution

263. Argentina claims that the Orion (Botnia) mill has caused air,
noise and visual pollution which negatively impact on “the aquatic envi-
ronment” in violation of Article 41 of the 1975 Statute. Argentina also

90argues that the 1975 Statute was concluded not only to protect the qual-
ity of the waters, but also, more generally, the “régime” of the river and

“the areas affected by it, i.e., all the factors that affect, and are affected
by the ecosystem of the river as a whole”. Uruguay contends that the
Court has no jurisdiction over those matters and that, in any event, the
claims are not established on the merits.

264. With respect to noise and visual pollution, the Court has already
concluded in paragraph 52 that it has no jurisdiction on such matters
under the 1975 Statute. As regards air pollution, the Court is of the view
that if emissions from the plant’s stacks have deposited into the aquatic
environment substances with harmful effects, such indirect pollution of

the river would fall under the provisions of the 1975 Statute. Uruguay
appears to agree with this conclusion. Nevertheless, in view of the ﬁnd-
ings of the Court with respect to water quality, it is the opinion of the
Court that the record does not show any clear evidence that substances
with harmful effects have been introduced into the aquatic environment
of the river through the emissions of the Orion (Botnia) mill into the air.

(f) Conclusions on Article 41

265. It follows from the above that there is no conclusive evidence in
the record to show that Uruguay has not acted with the requisite degree
of due diligence or that the discharges of efﬂuent from the Orion (Botnia)
mill have had deleterious effects or caused harm to living resources or to

the quality of the water or the ecological balance of the river since it
started its operations in November 2007. Consequently, on the basis of
the evidence submitted to it, the Court concludes that Uruguay has not
breached its obligations under Article 41.

(g) Continuing obligations: monitoring

266. The Court is of the opinion that both Parties have the obligation
to enable CARU, as the joint machinery created by the 1975 Statute, to
exercise on a continuous basis the powers conferred on it by the 1975 Stat-
ute, including its function of monitoring the quality of the waters of the
river and of assessing the impact of the operation of the Orion (Botnia)

mill on the aquatic environment. Uruguay, for its part, has the obligation
to continue monitoring the operation of the plant in accordance with
Article 41 of the Statute and to ensure compliance by Botnia with Uru-
guayan domestic regulations as well as the standards set by CARU. The
Parties have a legal obligation under the 1975 Statute to continue their
co-operation through CARU and to enable it to devise the necessary

means to promote the equitable utilization of the river, while protecting
its environment.

**

91 V. T HE C LAIMS M ADE BY THE PARTIES

IN THEIR F INAL SUBMISSIONS

267. Having concluded that Uruguay breached its procedural obliga-

tions under the 1975 Statute (see paragraphs 111, 122, 131, 149, 157 and
158 above), it is for the Court to draw the conclusions following from
these internationally wrongful acts giving rise to Uruguay’s international
responsibility and to determine what that responsibility entails.

268. Argentina ﬁrst requests the Court to ﬁnd that Uruguay has vio-
lated the procedural obligations incumbent on it under the 1975 Statute
and has thereby engaged its international responsibility. Argentina further

requests the Court to order that Uruguay immediately cease these inter-
nationally wrongful acts.
269. The Court considers that its ﬁnding of wrongful conduct by Uru-

guay in respect of its procedural obligations per se constitutes a measure
of satisfaction for Argentina. As Uruguay’s breaches of the procedural
obligations occurred in the past and have come to an end, there is no
cause to order their cessation.

270. Argentina nevertheless argues that a ﬁnding of wrongfulness
would be insufﬁcient as reparation, even if the Court were to ﬁnd that
Uruguay has not breached any substantive obligation under the 1975 Stat-

ute but only some of its procedural obligations. Argentina maintains that
the procedural obligations and substantive obligations laid down in the
1975 Statute are closely related and cannot be severed from one another
for purposes of reparation, since undesirable effects of breaches of the

former persist even after the breaches have ceased. Accordingly, Argen-
tina contends that Uruguay is under an obligation to “re-establish on the
ground and in legal terms the situation that existed before [the] interna-
tionally wrongful acts were committed”. To this end, the Orion

(Botnia) mill should be dismantled. According to Argentina, restitutio in
integrum is the primary form of reparation for internationally wrongful
acts. Relying on Article 35 of the International Law Commission’s
Articles on the Responsibility of States for Internationally Wrongful Acts,

Argentina maintains that restitution takes precedence over all other forms
of reparation except where it is “materially impossible” or involves
“a burden out of all proportion to the beneﬁt deriving from restitution
instead of compensation”. It asserts that dismantling the mill is not mat-

erially impossible and would not create for the Respondent State a
burden out of all proportion, since the Respondent has

“maintained that construction of the mills would not amount to a

fait accompli liable to prejudice Argentina’s rights and that it was
for Uruguay alone to decide whether to proceed with construction

92 and thereby assume the risk of having to dismantle the mills in the
event of an adverse decision by the Court”,

as the Court noted in its Order on Argentina’s request for the indication
of provisional measures in this case (Order of 13 July 2006, I.C.J.
Reports 2006, p. 125, para. 47). Argentina adds that whether or not
restitution is disproportionate must be determined at the latest as of the

ﬁling of the Application instituting proceedings, since as from that time
Uruguay, knowing of Argentina’s request to have the work halted and
the status quo ante re-established, could not have been unaware of the
risk it ran in proceeding with construction of the disputed mill. Lastly,
Argentina considers Articles 42 and 43 of the 1975 Statute to be inappli-

cable in the present case, since they establish a régime of responsibility in
the absence of any wrongful act.

271. Taking the view that the procedural obligations are distinct from
the substantive obligations laid down in the 1975 Statute, and that
account must be taken of the purport of the rule breached in determining

the form to be taken by the obligation of reparation deriving from its
violation, Uruguay maintains that restitution would not be an appropri-
ate form of reparation if Uruguay is found responsible only for breaches
of procedural obligations. Uruguay argues that the dismantling of the
Orion (Botnia) mill would at any rate involve a “striking disproportion

between the gravity of the consequences of the wrongful act of which it is
accused and those of the remedy claimed”, and that whether or not a dis-
proportionate burden would result from restitution must be determined
as of when the Court rules, not, as Argentina claims, as of the date it was
seised. Uruguay adds that the 1975 Statute constitutes a lex specialis in

relation to the law of international responsibility, as Articles 42 and 43
establish compensation, not restitution, as the appropriate form of repa-
ration for pollution of the river in contravention of the 1975 Statute.

272. The Court, not having before it a claim for reparation based on a

régime of responsibility in the absence of any wrongful act, deems it
unnecessary to determine whether Articles 42 and 43 of the 1975 Statute
establish such a régime. But it cannot be inferred from these Articles,
which speciﬁcally concern instances of pollution, that their purpose or
effect is to preclude all forms of reparation other than compensation for
breaches of procedural obligations under the 1975 Statute.

273. The Court recalls that customary international law provides for
restitution as one form of reparation for injury, restitution being the
re-establishment of the situation which existed before occurrence of the
wrongful act. The Court further recalls that, where restitution is materi-

ally impossible or involves a burden out of all proportion to the beneﬁt
deriving from it, reparation takes the form of compensation or satisfac-
tion, or even both (seeGabcˇíkovo-Nagymaros Project (Hungary/Slovakia),

93Judgment, I.C.J. Reports 1997, p. 81, para. 152; Legal Consequences
of the Construction of a Wall in the Occupied Palestinian Territory,

Advisory Opinion, I.C.J. Reports 2004 (I) , p. 198, paras. 152-153;
Application of the Convention on the Prevention and Punishment of the
Crime of Genocide (Bosnia and Herzegovina v. Serbia and Montenegro),
Judgment, I.C.J. Reports 2007 (I) , p. 233, para. 460; see also Articles 34
to 37 of the International Law Commission Articles on the Responsibil-

ity of States for Internationally Wrongful Acts).

274. Like other forms of reparation, restitution must be appropriate to
the injury suffered, taking into account the nature of the wrongful act
having caused it. As the Court has made clear,

“[w]hat constitutes ‘reparation in an adequate form’ clearly varies
depending upon the concrete circumstances surrounding each case
and the precise nature and scope of the injury, since the question has

to be examined from the viewpoint of what is the ‘reparation in an
adequate form’ that corresponds to the injury” (Avena and Other
Mexican Nationals (Mexico v. United States of America), Judg-
ment, I.C.J. Reports 2004 (I) , p. 59, para. 119).

275. As the Court has pointed out (see paragraphs 154 to 157 above),
the procedural obligations under the 1975 Statute did not entail any
ensuing prohibition on Uruguay’s building of the Orion (Botnia) mill,

failing consent by Argentina, after the expiration of the period for nego-
tiation. The Court has however observed that construction of that mill
began before negotiations had come to an end, in breach of the proce-
dural obligations laid down in the 1975 Statute. Further, as the Court has
found, on the evidence submitted to it, the operation of the Orion (Bot-

nia) mill has not resulted in the breach of substantive obligations laid
down in the 1975 Statute (paragraphs 180, 189 and 265 above). As Uru-
guay was not barred from proceeding with the construction and opera-
tion of the Orion (Botnia) mill after the expiration of the period for
negotiation and as it breached no substantive obligation under the

1975 Statute, ordering the dismantling of the mill would not, in the view
of the Court, constitute an appropriate remedy for the breach of proce-
dural obligations.

276. As Uruguay has not breached substantive obligations arising
under the 1975 Statute, the Court is likewise unable, for the same rea-

sons, to uphold Argentina’s claim in respect of compensation for alleged
injuries suffered in various economic sectors, speciﬁcally tourism and
agriculture.
277. Argentina further requests the Court to adjudge and declare that
Uruguay must “provide adequate guarantees that it will refrain in future

from preventing the Statute of the River Uruguay of 1975 from being
applied, in particular the consultation procedure established by Chap-
ter II of that Treaty”.

94 278. The Court fails to see any special circumstances in the present
case requiring the ordering of a measure such as that sought by Argen-

tina. As the Court has recently observed:
“[W]hile the Court may order, as it has done in the past, a State

responsible for internationally wrongful conduct to provide the
injured State with assurances and guarantees of non-repetition, it
will only do so if the circumstances so warrant, which it is for the
Court to assess.
As a general rule, there is no reason to suppose that a State whose

act or conduct has been declared wrongful by the Court will repeat
that act or conduct in the future, since its good faith must be pre-
sumed (see Factory at Chorzów, Merits, Judgment No. 13, 1928,
P.C.I.J., Series A, No. 17 ,p.63;Nuclear Tests (Australia v. France),
Judgment, I.C.J. Reports 1974 , p. 272, para. 60; Nuclear Tests
(New Zealand v. France), Judgment, I.C.J. Reports 1974 , p. 477,

para. 63; and Military and Paramilitary Activities in and against
Nicaragua (Nicaragua v. United States of America), Jurisdiction
and Admissibility, Judgment, I.C.J. Reports 1984 , p. 437, para. 101).
There is thus no reason, except in special circumstances . . . to order
[the provision of assurances and guarantees of non-repetition].”

(Dispute regarding Navigational and Related Rights (Costa Rica v.
Nicaragua), Judgment, I.C.J. Reports 2009 , p. 267, para. 150.)

279. Uruguay, for its part, requests the Court to conﬁrm its right “to
continue operating the Botnia plant in conformity with the provisions of
the 1975 Statute”. Argentina contends that this claim should be rejected,
in particular because it is a counter-claim ﬁrst put forward in Uruguay’s
Rejoinder and, as such, is inadmissible by virtue of Article 80 of the

Rules of Court.
280. There is no need for the Court to decide the admissibility of this
claim; it is sufﬁcient to observe that Uruguay’s claim is without any prac-
tical signiﬁcance, since Argentina’s claims in relation to breaches by Uru-
guay of its substantive obligations and to the dismantling of the Orion

(Botnia) mill have been rejected.

* * *

281. Lastly, the Court points out that the 1975 Statute places the
Parties under a duty to co-operate with each other, on the terms therein

set out, to ensure the achievement of its object and purpose. This obliga-
tion to co-operate encompasses ongoing monitoring of an industrial
facility, such as the Orion (Botnia) mill. In that regard the Court notes
that the Parties have a long-standing and effective tradition of co-opera-
tion and co-ordination through CARU. By acting jointly through CARU,

the Parties have established a real community of interests and rights in
the management of the River Uruguay and in the protection of its envi-
ronment. They have also co-ordinated their actions through the joint

95mechanism of CARU, in conformity with the provisions of the 1975 Stat-

ute, and found appropriate solutions to their differences within its frame-
work without feeling the need to resort to the judicial settlement of
disputes provided for in Article 60 of the Statute until the present case
was brought before the Court.

* * *

282. For these reasons,

T HE C OURT ,

(1) By thirteen votes to one,
Finds that the Eastern Republic of Uruguay has breached its proce-

dural obligations under Articles 7 to 12 of the 1975 Statute of the River
Uruguay and that the declaration by the Court of this breach constitutes
appropriate satisfaction;

IN FAVOUR : Vice-President Tomka, Acting President ; Judges Koroma, Al-
Khasawneh, Simma, Abraham, Keith, Sepúlveda-Amor, Bennouna, Skot-
nikov, Cançado Trindade, Yusuf, Greenwood; Judge ad hoc Vinuesa;

AGAINST: Judge ad hoc Torres Bernárdez;

(2) By eleven votes to three,

Finds that the Eastern Republic of Uruguay has not breached its sub-
stantive obligations under Articles 35, 36 and 41 of the 1975 Statute of

the River Uruguay;
IN FAVOUR: Vice-President Tomka, Acting President ; Judges Koroma, Abra-
ham, Keith, Sepúlveda-Amor, Bennouna, Skotnikov, Cançado Trindade,
Yusuf, Greenwood; Judge ad hoc Torres Bernárdez;

AGAINST: Judges Al-Khasawneh, Simma; Judge ad hoc Vinuesa;

(3) Unanimously,
Rejects all other submissions by the Parties.

Done in French and in English, the French text being authoritative, at
the Peace Palace, The Hague, this twentieth day of April, two thousand
and ten, in three copies, one of which will be placed in the archives of the

Court and the others transmitted to the Government of the Argentine
Republic and the Government of the Eastern Republic of Uruguay,
respectively.

(Signed) Vice-President. (Signed) Peter T OMKA ,
Vice-President.

(Signed) Philippe C OUVREUR ,

Registrar.

96 Judges A L-KHASAWNEH and SIMMA append a joint dissenting opinion

to the Judgment of the Court; Judge EITH appends a separate opinion
to the Judgment of the Court; JudgKOTNIKOV appends a declaration to
the Judgment of the Court; Judge C ANÇADO TRINDADE appends a

separate opinion to the Judgment of the Court; JudgeUSUF appends a
declaration to the Judgment of the Court; JudgeREENWOOD appends a
separate opinion to the Judgment of the Court; Judge ad hoc

TORRES B ERNÁRDEZ appends a separate opinion to the Judgment of the
Court; Judge ad hoc VINUESA appends a dissenting opinion to the Judg-
ment of the Court.

(Initialled) P.T.

(Initialled) Ph.C.

97

Bilingual Content

COUR INTERNATIONALE DE JUSTICE

RECUEIL DES A|TS,
AVIS CONSULTATIFS ET ORDONNANCES

AFFAIRE RELATIVE A v DES USINES DE PÂTE
v PAPIER SUR LE FLEUVE URUGUAY

(ARGENTINE c. URUGUAY)

ARR|T DU 20 AVRIL 2010

2010

INTERNATIONAL COURT OF JUSTICE

REPORTS OF JUDGMENTS,
ADVISORY OPINIONS AND ORDERS

CASE CONCERNING PULP MILLS
ON THE RIVER URUGUAY

(ARGENTINA v. URUGUAY)

JUDGMENT OF 20 APRIL 2010 Mode ofﬁciel de citation:
Usines de pâte à papier sur le ﬂeuve Uruguay (Argentine c. Uruguay),
arrêt, C.I.J. Recueil 2010 ,p.14

Ofﬁcial citation:
Pulp Mills on the River Uruguay (Argentina v. Uruguay),
Judgment, I.C.J. Reports 2010 ,p.14

Sales number
ISSN 0074-4441 N de vente: 977
ISBN 978-92-1-071089-3 20 AVRIL 2010

ARRE|T

USINES DE P|TE v PAPIER SUR LE FLEUVE URUGUAY
(ARGENTINE c. URUGUAY)

PULP MILLS ON THE RIVER URUGUAY

(ARGENTINA v. URUGUAY)

20 APRIL 2010

JUDGMENT TABLE DES MATIE vRES

Paragraphes

Q UALITÉS 1-24

I. CADRE JURIDIQUE ET FAITS DE ’ESPÈCE 25-47
A. Cadre juridique 26-27
B. Le projet CMB (ENCE) 28-36
C. L’usine Orion (Botnia) 37-47

II. ÉTENDUE DE LA COMPÉTENCE DE LA C OUR 48-66

III. LA VIOLATION ALLÉGUÉE DES OBLIGATIONS DE NATURE PROCÉDURALE 67-158

A. Les liens entre les obligations de nature procédurale et les
obligations de fond 71-79
B. Les obligations de nature procédurale et leur articulation 80-122

1. La nature et le rôle de la CARU 84-93
2. L’obligation de l’Uruguay d’informer la CARU 94-111
3. L’obligation de l’Uruguay de notiﬁer les projets à l’autre
partie 112-122
C. Les Parties sont-elles convenues de déroger aux obligations

de nature procédurale prévues dans le statut de 1975? 123-150
1. L’«arrangement» du 2 mars 2004 entre l’Argentine et
l’Uruguay 125-131
2. L’accord créant le Groupe technique de haut niveau
(GTAN) 132-150

D. Les obligations de l’Uruguay après l’expiration de la période
de négociation 151-158

IV. L ES OBLIGATIONS DE FOND 159-266

A. La charge de la preuve et la preuve par expertise 160-168
B. Les violations alléguées des obligations de fond 169-266
1. L’obligation de contribuer à l’utilisation rationnelle et
optimale du ﬂeuve (article premier) 170-177
2. L’obligation de veiller à ce que la gestion du sol et des

forêts ne cause pas un préjudice au régime du ﬂeuve ou à
la qualité de ses eaux (article 35) 178-180
3. L’obligation de coordonner les mesures propres à éviter
une modiﬁcation de l’équilibre écologique (article 36) 181-189
4. L’obligation d’empêcher la pollution et de préserver le
milieu aquatique (article 41) 190-266

a) Evaluation de l’impact sur l’environnement 203-219
i) Le choix du site de Fray Bentos pour l’usine Orion
(Botnia) 207-214
ii) Consultation des populations concernées 215-219

4 TABLE OF CONTENTS

Paragraphs

C HRONOLOGY OF THE PROCEDURE 1-24

I. EGAL F RAMEWORK AND F ACTS OF THECASE 25-47

A. Legal framework 26-27
B. CMB (ENCE) Project 28-36
C. Orion (Botnia) mill 37-47

II. COPE OF THE COURT’S URISDICTION 48-66

III. HE A LLEGED BREACH OF P ROCEDURAL O BLIGATIONS 67-158
A. The links between the procedural obligations and the sub-
stantive obligations 71-79
B. The procedural obligations and their interrelation 80-122

1. The nature and role of CARU 84-93
2. Uruguay’s obligation to inform CARU 94-111
3. Uruguay’s obligation to notify the plans to the other

party 112-122
C. Whether the Parties agreed to derogate from the procedural
obligations set out in the 1975 Statute 123-150

1. The “understanding” of 2 March 2004 between Argen-
tina and Uruguay 125-131
2. The agreement setting up the High-Level Technical
Group (the GTAN) 132-150

D. Uruguay’s obligations following the end of the negotiation
period 151-158

IV. SUBSTANTIVE OBLIGATIONS 159-266

A. Burden of proof and expert evidence 160-168
B. Alleged violations of substantive obligations 169-266
1. The obligation to contribute to the optimum and rational
utilization of the river (Article 1) 170-177

2. The obligation to ensure that the management of the soil
and woodland does not impair the régime of the river or
the quality of its waters (Article 35) 178-180
3. The obligation to co-ordinate measures to avoid changes
in the ecological balance (Article 36) 181-189
4. The obligation to prevent pollution and preserve the
aquatic environment (Article 41) 190-266

(a) Environmental Impact Assessment 203-219

(i) The siting of the Orion (Botnia) mill at Fray
Bentos 207-214
(ii) Consultation of the affected populations 215-219

4 b) La question des techniques de production utilisées à
l’usine Orion (Botnia) 220-228
c) L’impact des rejets sur la qualité des eaux du ﬂeuve 229-259

i) L’oxygène dissous 238-239
ii) Le phosphore 240-250
iii) Les substances phénoliques 251-254
iv) La présence de nonylphénols dans le milieu aqua-

tique 255-257
v) Les dioxines et furanes 258-259
d) Effets sur la diversité biologique 260-262
e) Pollution atmosphérique 263-264

f) Conclusions relatives à l’article 41 265
g) Obligations continues: suivi et contrôle 266

V. L ES DEMANDES PRÉSENTÉES PAR LES P ARTIES DANS LEURS CONCLU -
SIONS FINALES 267-281

D ISPOSITIF 282

5 (b) Question of the production technology used in the
Orion (Botnia) mill 220-228
(c) Impact of the discharges on the quality of the waters

of the river 229-259
(i) Dissolved oxygen 238-239
(ii) Phosphorus 240-250

(iii) Phenolic substances 251-254
(iv) Presence of nonylphenols in the river environ-
ment 255-257
(v) Dioxins and furans 258-259

(d) Effects on biodiversity 260-262
(e) Air pollution 263-264
(f) Conclusions on Article 41 265
(g) Continuing obligations: monitoring 266

V. THE C LAIMSM ADE BY THE PARTIES IT HEIRF INALSUBMISSIONS 267-281

O PERATIVECLAUSE 282

5 ABRÉVIATIONS ET ACRONYMES

AAP «Autorización Ambiental Previa» (autorisation environnemen-

tale préalable)
ADCP «Acoustic Doppler Current Proﬁler» (proﬁleur de courant à
effet Doppler)
AOX «Adsorbable Organic Halogens» (composés organo-halogénés
adsorbables)
BAT «Best Available Techniques (or Technology)» (meilleures tech-
niques disponibles)
Botnia «Botnia S.A.» et «Botnia Fray Bentos S.A.» (deux sociétés de
droit uruguayen créées par la société ﬁnlandaise Oy Metsä-
Botnia AB)
CARU «Comisión Administradora del Río Uruguay» (commission
administrative du ﬂeuve Uruguay)
CIS «Cumulative Impact Study» (étude d’impact cumulé réalisée
en septembre 2006 à la demande de la Société ﬁnancière inter-
nationale)
CMB «Celulosas de M’Bopicuá S.A.» (société de droit uruguayen

créée par la société espagnole ENCE)
CMB (ENCE) Usine de pâte à papier projetée à Fray Bentos par la société
espagnole ENCE ayant créé à cette ﬁn la société uruguayenne
CMB
DINAMA «Dirección Nacional de Medio Ambiente» (direction nationale
de l’environnement du Gouvernement uruguayen)
ECF «Elemental Chlorine-Free» (exempt de chlore élémentaire)
EIE Evaluation de l’impact sur l’environnement
ENCE «Empresa Nacional de Celulosas de España» (société espa-
gnole ayant créé la société CMB de droit uruguayen)
GTAN «Grupo Técnico de Alto Nivel» (Groupe technique de haut
niveau créé en 2005 par l’Argentine et l’Uruguay pour résoudre
leur litige concernant les usines CMB (ENCE) et Orion (Bot-
nia))
IPPC-BAT «Integrated Pollution Prevention and Control Reference Docu-
ment on Best Available Techniques in the Pulp and Paper

Industry» (document de référence en matière de prévention et
de réduction intégrées de la pollution sur les meilleures techni-
ques disponibles dans l’industrie de la pâte et du papier)
MVOTMA «Ministerio de Vivienda, Ordenamiento Territorial y Medio
Ambiente» (ministère uruguayen du logement, de l’aménage-
ment du territoire et de l’environnement)
Orion (Botnia) Usine de pâte à papier construite à Fray Bentos par la société
ﬁnlandaise Oy Metsä-Botnia AB, ayant créé à cette ﬁn les
sociétés uruguayennes Botnia S.A. et Botnia Fray Bentos
S.A.
OSE «Obras Sanitarias del Estado» (organisme public uruguayen
chargé de l’assainissement et de la distribution de l’eau)

6 ABBREVIATIONS AND ACRONYMS

AAP “Autorización Ambiental Previa” (initialenvironmental

authorization)
ADCP Acoustic Doppler Current Proﬁler
AOX Adsorbable Organic Halogens
BAT Best Available Techniques (or Technology)
Botnia “Botnia S.A.” and “Botnia Fray Bentos S.A.” (two companies
formed under Uruguayan law by the Finnish company Oy
Metsä-Botnia AB)
CARU “Comisión Administradora del Río Uruguay” (Administrative
Commission of the River Uruguay)
CIS Cumulative Impact Study (prepared in September 2006 at the
request of the International Finance Corporation)
CMB Celulosas de M’Bopicuá S.A.” (a company formed under Uru-
guayan law by the Spanish company ENCE)
CMB (ENCE) Pulp mill planned at Fray Bentos by the Spanish company
ENCE, which formed the Uruguayan company CMB for that
purpose

DINAMA “Dirección Nacional de Medio Ambiente” (National Directo-
rate for the Environment of the Uruguayan Government)
ECF Elemental Chlorine-Free
EIA Environmental Impact Assessment
ENCE “Empresa Nacional de Celulosas de España” (Spanish com-
pany which formed the company CMB under Uruguayan law)
ESAP Environmental and Social Action Plan
GTAN “Grupo Técnico de Alto Nivel” (High-Level Technical Group
established in 2005 by Argentina and Uruguay to resolve their
dispute over the CMB (ENCE) and Orion (Botnia) mills)
IFC International Finance Corporation
IPPC-BAT Integrated Pollution Prevention and Control Reference Docu-
ment on Best Available Techniques in the Pulp and Paper
Industry
MVOTMA “Ministerio de Vivienda, Ordenamiento Territorial y Medio
Ambiente” (Uruguayan Ministry of Housing, Land Use Plan-

ning and Environmental Affairs)
Orion (Botnia) Pulp mill built at Fray Bentos by the Finnish company Oy
Metsä-Botnia AB, which formed the Uruguayan companies
Botnia S.A. and Botnia Fray Bentos S.A. for that purpose
OSE “Obras Sanitarias del Estado” (Uruguay’s State Agency for
Sanitary Works)
POPs Persistent Organic Pollutants
PROCEL “Plan de Monitoreo de la Calidad Ambiental en el Río Uru-
guay en áreas de Plantas Celulósicas” (Plan for monitoring
water quality in the area of the pulp mills set up under CARU)

6PAES Plan d’action environnemental et social
POP Polluants organiques persistants
PROCEL «Plan de Monitoreo de la Calidad Ambiental del Río Uruguay
en áreas de Plantas Celulósicas» (plan de contrôle et de suivi
(monitoring) de la qualité des eaux du ﬂeuve Uruguay dans la

zone des usines de pâte à papier, mis en place dans le cadre de
la CARU)
PROCON «Programa de Calidad de Aguas y Control de la Contamina-
ción del Río Uruguay» (programme de contrôle de la qualité et
de la pollution des eaux du ﬂeuve Uruguay, mis en place dans
le cadre de la CARU)
SFI Société ﬁnancière internationale

7PROCON “Programa de Calidad de Aguas y Control de la Contami-
nación del Río Uruguay” (Water quality and pollution control
programme set up under CARU)

7 COUR INTERNATIONALE DE JUSTICE

2010 ANNÉE 2010
20 avril
Rôlo général
n 135 20 avril 2010

AFFAIRE RELATIVE A v DES USINES DE PÂTE

Av PAPIER SUR LE FLEUVE URUGUAY

(ARGENTINE c. URUGUAY)

Cadre juridique et faits de l’espèce.
Traité de Montevideo de 1961 — Statut du ﬂeuve Uruguay de 1975 — Eta-
blissement de la commission administrative du ﬂeuve Uruguay (CARU) — Pro-
jet d’usine de pâte à papier CMB (ENCE) — Projet d’usine de pâte à papier
Orion (Botnia) — Terminal portuaire de Nueva Palmira — Objet du différend.

*

Etendue de la compétence de la Cour.
Clause compromissoire (article 60 du statut de 1975) — Dispositions du sta-
tut de 1975 et compétence ratione materiae — Incompétence de la Cour pour
connaître d’allégations relatives à la pollution sonore et visuelle ou aux mau-
vaises odeurs (article 36 du statut de 1975) — Pollution atmosphérique et
atteinte à la qualité des eaux du ﬂeuve examinées dans le cadre des obligations
de fond.
Article premier du statut de 1975 — Déﬁnition du but du statut
de 1975 — Mécanismes communs nécessaires à l’utilisation rationnelle et opti-
male du ﬂeuve — Portée de la référence aux «droits et obligations découlant des
traités et autres engagements internationaux en vigueur à l’égard de l’une ou
l’autre des parties» — Texte original espagnol — Statut adopté par les parties
dans le respect de leurs engagements internationaux respectifs.
Alinéa a)de l’article 41 du statut de 1975 — Texte original espagnol — Absence
de «clause de renvoi» ayant pour effet d’incorporer dans le champ d’application
du statut les obligations des parties découlant des accords internationaux et
autres normes qui y sont visées — Obligation des parties d’exercer leurs pouvoirs
de réglementation en conformité avec les accords internationaux applicables aux
ﬁns de la protection et de la préservation du milieu aquatique du ﬂeuve Uru-

guay — Règles d’interprétation du statut de 1975 — Article 31 de la convention

8 INTERNATIONAL COURT OF JUSTICE

YEAR 2010 2010
20 April
General List
20 April 2010 No. 135

CASE CONCERNING PULP MILLS

ON THE RIVER URUGUAY

(ARGENTINA v. URUGUAY)

Legal framework and facts of the case.
1961 Treaty of Montevideo — 1975 Statute of the River Uruguay — Estab-
lishment of the Administrative Commission of the River Uruguay (CARU) —
CMB (ENCE) pulp mill project — Orion (Botnia) pulp mill project — Port
terminal at Nueva Palmira — Subject of the dispute.

*

Scope of the Court’s jurisdiction.
Compromissory clause (Article 60 of the 1975 Statute) — Provisions of the
1975 Statute and jurisdiction ratione materiae — Lack of jurisdiction for the
Court to consider allegations concerning noise and visual pollution or bad
odours (Article 36 of the 1975 Statute) — Air pollution and impact on the qual-
ity of the waters of the river addressed under substantive obligations.

Article 1 of the 1975 Statute — Deﬁnition of the purpose of the 1975 Stat-
ute — Joint machinery necessary for the optimum and rational utilization of the
river — Signiﬁcance of the reference to the “rights and obligations arising from
treaties and other international agreements in force for each of the parties” —
Original Spanish text — Statute adopted by the parties in observance of their
respective international commitments.
Article 41 (a) of the 1975 Statute — Original Spanish text — Absence of a
“referral clause” having the effect of incorporating within the ambit of the Stat-
ute the obligations of the parties under international agreements and other
norms envisaged in the Statute — Obligation for the parties to exercise their
regulatory powers, in conformity with applicable international agreements, for
the protection and preservation of the aquatic environment of the River Uru-

guay — Rules for interpreting the 1975 Statute — Article 31 of the Vienna

8de Vienne sur le droit des traités — Distinction entre la prise en considération
d’autres règles internationales lors de l’interprétation du statut de 1975 et l’éten-
due de la compétence de la Cour en vertu de son article 60.

*

Violation alléguée des obligations de nature procédurale.
Question des liens entre les obligations de nature procédurale et les obliga-
tions de fond — Objet et but du statut de 1975 — Utilisation rationnelle et opti-
male du ﬂeuve Uruguay — Développement durable — Coopération entre les
parties pour la gestion commune des risques de dommages à l’environne-
ment — Existence d’un lien fonctionnel, relatif à la prévention, entre les obli-
gations de nature procédurale et les obligations de fond — Responsabilité en cas
de violation des unes ou des autres.
Articulation des différentes obligations de nature procédurale prévues par les
articles 7 à 12 du statut de 1975 — Texte original espagnol de l’article 7 — Obli-
gation d’informer, de notiﬁer et de négocier comme moyen approprié de parvenir
à l’objectif d’utilisation rationnelle et optimale du ﬂeuve en tant que ressource
partagée — Personnalité juridique de la CARU — Rôle central de la CARU

dans la gestion commune du ﬂeuve et l’obligation de coopérer entre les parties.
Obligation d’informer la CARU (premier alinéa de l’article 7 du statut de
1975) — Ouvrages soumis à cette obligation — Lien entre l’obligation d’infor-
mer la CARU, la coopération entre les parties et l’obligation de préven-
tion — Détermination sommaire par la CARU d’un risque de préjudice sensible
à l’autre partie — Contenu de l’information devant être transmise à la
CARU — Obligation d’informer la CARU avant la délivrance de l’autorisation
environnementale préalable — L’information de la CARU par des opérateurs
privés ne peut tenir lieu de l’obligation d’informer prévue par le statut
de 1975 — Violation par l’Uruguay de l’obligation d’informer la CARU.
Obligation de notiﬁer les projets à l’autre partie (deuxième et troisième ali-
néas de l’article 7 du statut de 1975) — Nécessité de disposer d’une évaluation
de l’impact sur l’environnement (EIE) complète — Notiﬁcation de l’EIE à

l’autre partie par l’intermédiaire de la CARU avant toute décision relative à la
viabilité environnementale du projet — Violation par l’Uruguay de l’obligation
de notiﬁer les projets à l’Argentine.
Question de l’éventuelle dérogation aux obligations de nature procédurale
convenue entre les Parties — «Arrangement» du 2 mars 2004 — Contenu et
portée — L’Uruguay ne s’y étant pas conformé, l’«arrangement» ne peut être
considéré comme ayant eu pour effet de le dispenser du respect des obligations
de nature procédurale — Accord créant le Groupe technique de haut niveau
(GTAN) — Saisine de la Cour sur la base de l’article 12 ou de l’article 60 du
statut de 1975: distinction sans incidence — L’accord créant le GTAN a eu
pour but de permettre aux négociations prévues à l’article 12 du statut de 1975
d’avoir lieu, mais il n’a pas dérogé à d’autres obligations de nature procédu-
rale — En acceptant la création du GTAN, l’Argentine n’a renoncé ni aux

droits de nature procédurale que lui reconnaît le statut, ni à invoquer la respon-
sabilité de l’Uruguay; l’Argentine n’a pas davantage consenti à suspendre
l’application des dispositions procédurales du statut (article 57 de la convention
de Vienne sur le droit des traités) — Obligation de négocier de bonne foi — Obli-
gation de «non-construction» durant la période de négociation — Travaux pré-
liminaires autorisés par l’Uruguay — Violation par l’Uruguay de l’obligation de
négocier prévue à l’article 12 du statut de 1975.

9Convention on the Law of Treaties — Distinction between taking account of
other international rules in the interpretation of the 1975 Statute and the scope
of the jurisdiction of the Court under Article 60 of the latter.

*

Alleged breach of procedural obligations.
Question of links between the procedural obligations and the substantive obli-
gations — Object and purpose of the 1975 Statute — Optimum and rational
utilization of the River Uruguay — Sustainable development — Co-operation
between the parties in jointly managing the risks of damage to the environ-
ment — Existence of a functional link, in regard to prevention, between the pro-
cedural obligations and the substantive obligations — Responsibility in the event
of breaches of either category.
Interrelation of the various procedural obligations laid down by Articles 7 to
12 of the 1975 Statute — Original Spanish text of Article 7 — Obligation to
inform, notify and negotiate as an appropriate means of achieving the objective
of optimum and rational utilization of the river as a shared resource — Legal
personality of CARU — Central role of CARU in the joint management of the

river and obligation of the parties to co-operate.
Obligation to inform CARU (Article 7, ﬁrst paragraph, of the 1975 Stat-
ute) — Works subject to this obligation — Link between the obligation to
inform CARU, co-operation between the parties and the obligation of preven-
tion — Determination by CARU on a preliminary basis of whether there is a
risk of signiﬁcant damage to the other party — Content of the information to be
transmitted to CARU — Obligation to inform CARU before issuing of the ini-
tial environmental authorization — Provision of information to CARU by pri-
vate operators cannot substitute for the obligation to inform laid down by the
1975 Statute — Breach by Uruguay of the obligation to inform CARU.
Obligation to notify the plans to the other party (Article 7, second and third
paragraphs, of the 1975 Statute) — Need for a full environmental impact
assessment (EIA) — Notiﬁcation of the EIA to the other party, through

CARU, before any decision on the environmental viability of the plan — Breach
by Uruguay of the obligation to notify the plans to Argentina.

Question of whether the Parties agreed to derogate from the procedural obli-
gations — “Understanding” of 2 March 2004 — Content and scope — Since
Uruguay did not comply with it, the “understanding” cannot be regarded as
having had the effect of exempting Uruguay from compliance with the proce-
dural obligations — Agreement setting up the High-Level Technical Group
(GTAN) — Referral to the Court on the basis of Article 12 or Article 60 of the
1975 Statute: no practical distinction — The agreement to set up the GTAN
had the aim of enabling the negotiations provided for in Article 12 of the 1975
Statute to take place, but did not derogate from other procedural obligations —
In accepting the creation of the GTAN, Argentina did not give up the procedural

rights belonging to it by virtue of the Statute, nor the possibility of invoking
Uruguay’s responsibility; nor did Argentina consent to suspending the operation
of the procedural provisions of the Statute (Article 57 of the Vienna Convention
on the Law of Treaties) — Obligation to negotiate in good faith — “No con-
struction obligation” during the negotiation period — Preliminary work
approved by Uruguay — Breach by Uruguay of the obligation to negotiate laid
down by Article 12 of the 1975 Statute.

9 Obligations de l’Uruguay après l’expiration de la période de négocia-
tion — Portée de l’article 12 du statut de 1975 — Absence d’obligation de «non-
construction» après l’expiration de la période de négociation et pendant la phase
de règlement judiciaire.

*

Violations alléguées des obligations de fond.
Charge de la preuve — Approche de précaution et absence de renversement de
la charge de la preuve — Preuve par expertise — Rapports établis à la demande
des Parties — Indépendance des experts — Appréciation des faits par la
Cour — Experts intervenus à l’audience en qualité de conseils — Question des
témoins, experts et témoins-experts.
Utilisation rationnelle et optimale du ﬂeuve Uruguay — Déﬁnissant le but du
statut de 1975, l’article premier ne crée pas de droits ou obligations spéciﬁ-
ques — Obligation de se conformer aux obligations prescrites par le statut aux
ﬁns de la protection de l’environnement et de la gestion conjointe du
ﬂeuve — Fonction réglementaire de la CARU — Lien étroit entre l’utilisation
équitable et raisonnable du ﬂeuve comme ressource partagée et la nécessité,

qui est au cŒur du développement durable, de concilier le développement écono-
mique et la protection de l’environnement (article 27 du statut de 1975).

Obligation de veiller à ce que la gestion du sol et des forêts ne cause pas un
préjudice au régime du ﬂeuve ou à la qualité de ses eaux (article 35 du statut
de 1975) — Allégations de l’Argentine non établies.
Obligation de coordonner les mesures propres à éviter une modiﬁcation de
l’équilibre écologique (article 36 du statut de 1975) — Exigence d’une action
individuelle de chaque partie et d’une action concertée par l’intermédiaire de la
CARU — Obligation de diligence requise («due diligence») — L’Argentine n’a
pas démontré de manière convaincante que l’Uruguay a refusé de prendre part
aux efforts de coordination prévus par l’article 36 du statut de 1975.
Obligation d’empêcher la pollution et de préserver le milieu aquati-

que — Contenu normatif de l’article 41 du statut de 1975 — Obligation pour
chaque partie d’adopter des normes et mesures destinées à protéger et préserver
le milieu aquatique et, en particulier, à empêcher la pollution — Les normes et
mesures adoptées par chaque partie doivent être conformes aux accords inter-
nationaux applicables et, le cas échéant, en harmonie avec les directives et
recommandations des organismes techniques internationaux — Obligation de
diligence requise («due diligence») d’adopter des normes et mesures et de les
mettre en Œuvre — Déﬁnition de la pollution selon l’article 40 du statut
de 1975 — Activité réglementaire de la CARU (article 56 du statut de 1975),
complémentaire à celle de chaque partie — Digeste de la CARU — Règles à
l’aune desquelles l’existence d’effets nocifs doit s’apprécier: statut de 1975,
digeste de la CARU, droit interne de chacune des parties dans la mesure exigée
par le statut de 1975.

Evaluation de l’impact sur l’environnement (EIE) — Obligation de procéder
à une EIE — Portée et contenu de l’EIE — Renvoi au droit interne — Question
du choix du site des usines comme élément de l’EIE — La Cour n’est pas
convaincue par l’argument de l’Argentine selon lequel une évaluation des diffé-
rents sites possibles n’a pas eu lieu — Capacité de réception des eaux du ﬂeuve
à Fray Bentos et inversions de courant — Les normes de la CARU relatives à la
qualité des eaux tiennent compte des caractéristiques géomorphologiques et

10 Obligations of Uruguay following the end of the negotiation period — Scope
of Article 12 of the 1975 Statute — Absence of a “no construction obligation”
following the end of the negotiation period and during the judicial settlement
phase.

*

Alleged breaches of substantive obligations.
Burden of proof — Precautionary approach without reversal of the burden of
proof — Expert evidence — Reports commissioned by the Parties — Independ-
ence of experts — Consideration of the facts by the Court — Experts appearing
as counsel at the hearings — Question of witnesses, experts and expert wit-
nesses.
Optimum and rational utilization of the River Uruguay — Article 1 of the
1975 Statute sets out the purpose of the instrument and does not lay down
speciﬁc rights and obligations — Obligation to comply with the obligations
prescribed by the Statute for the protection of the environment and the joint
management of the river — Regulatory function of CARU — Interconnected-
ness between equitable and reasonable utilization of the river as a shared

resource and the balance between economic development and environmental
protection that is the essence of sustainable development (Article 27 of the 1975
Statute).
Obligation to ensure that the management of the soil and woodland does not
impair the régime of the river or the quality of its waters (Article 35 of the 1975
Statute) — Contentions of Argentina not established.
Obligation to co-ordinate measures to avoid changes to the ecological balance
(Article 36 of the 1975 Statute) — Requirement of individual action by each
party and co-ordination through CARU — Obligation of due diligence —
Argentina has not convincingly demonstrated that Uruguay has refused to
engage in the co-ordination envisaged by Article 36 of the 1975 Statute.

Obligation to prevent pollution and preserve the aquatic environment — Norm-

ative content of Article 41 of the 1975 Statute — Obligation for each party to
adopt rules and measures to protect and preserve the aquatic environment and,
in particular, to prevent pollution — The rules and measures prescribed by each
party must be in accordance with applicable international agreements and in
keeping, where relevant, with the guidelines and recommendations of interna-
tional technical bodies — Due diligence obligation to prescribe rules and meas-
ures and to apply them — Deﬁnition of pollution given in Article 40 of the
1975 Statute — Regulatory action of CARU (Article 56 of the 1975 Statute),
complementing that of each party — CARU Digest — Rules by which the exist-
ence of any harmful effects is to be determined: 1975 Statute, CARU Digest,
domestic law of each party within the limits prescribed by the 1975 Statute.

Environmental impact assessment (EIA) — Obligation to conduct an EIA —
Scope and content of the EIA — Referral to domestic law — Question of the
choice of mill site as part of the EIA — The Court is not convinced by Argen-
tina’s argument that an assessment of possible sites was not carried out —
Receiving capacity of the river at Fray Bentos and reverse ﬂows — The CARU
water quality standards take account of the geomorphological and hydrological
characteristics of the river and the receiving capacity of its waters — Question

10hydrologiques du ﬂeuve et de la capacité de réception de ses eaux — Question de
la consultation des populations concernées comme élément de l’EIE — Aucune
obligation juridique de consulter les populations concernées ne découle des ins-
truments invoqués par l’Argentine — Une consultation par l’Uruguay des popu-
lations concernées a bien eu lieu.
Techniques de production utilisées à l’usine Orion (Botnia) — Aucun élément

ne vient à l’appui de la prétention de l’Argentine selon laquelle l’usine Orion
(Botnia) n’appliquerait pas les meilleures techniques disponibles en matière de
rejets d’efﬂuents par tonne de pâte à papier produite — Il ne ressort pas des
données réunies après la mise en service de l’usine Orion (Botnia) que ses rejets
ont excédé les limites autorisées.
Impact des rejets de l’usine sur la qualité des eaux du ﬂeuve — Contrôle et
suivi postopérationnel — Oxygène dissous — Phosphore — Prolifération
d’algues — Substances phénoliques — Présence de nonylphénols dans le milieu
aquatique — Dioxines et furanes — Violations alléguées non établies.
Effets sur la diversité biologique — Eléments de preuve insufﬁsants pour
conclure que l’Uruguay n’a pas respecté l’obligation de protéger le milieu aqua-
tique, y compris la faune et la ﬂore.
Pollution atmosphérique — Pollution indirecte par dépôt dans le milieu aqua-

tique — Eléments de preuve insufﬁsants.
Sur la base des preuves présentées, absence de violation de l’article 41 du sta-
tut de 1975 par l’Uruguay.
Obligations continues: suivi et contrôle — Obligation des Parties de veiller à
ce que la CARU puisse continûment exercer ses pouvoirs au titre du statut
de 1975 — Obligation de l’Uruguay de poursuivre le contrôle et le suivi du fonc-
tionnement de l’usine Orion (Botnia) — Obligation des Parties de poursuivre
leur coopération par l’intermédiaire de la CARU.

*
Demandes présentées par les Parties dans leurs conclusions ﬁnales.
Demandes de l’Argentine — Violation des obligations de nature procédu-

rale — Constat d’illicéité et satisfaction — Formes de réparation autres que
l’indemnisation non exclues par le statut de 1975 — Restitution en tant que
forme de réparation du préjudice — Déﬁnition — Limites — Caractère appro-
prié de la forme de réparation par rapport au préjudice subi, compte tenu du
fait illicite — Caractère inapproprié de la restitution sous la forme du déman-
tèlement de l’usine Orion (Botnia) dans le cas d’une violation des seules obliga-
tions de nature procédurale — Absence de violation des obligations de fond et
rejet des autres réclamations présentées par l’Argentine — Absence de circon-
stances spéciales requérant d’ordonner des assurances et garanties de non-
répétition.
Demande de l’Uruguay visant à conﬁrmer son droit de poursuivre l’exploita-
tion de l’usine Orion (Botnia) — Absence de portée utile.

*

Obligation des Parties de coopérer entre elles selon les modalités prévues par
le statut de 1975 aﬁn d’assurer la réalisation de son objet et de son but — Action
conjointe des Parties au sein de la CARU et établissement d’une réelle commu-
nauté d’intérêts et de droits dans la gestion du ﬂeuve Uruguay et dans la protec-
tion de son environnement.

11of consultation of the affected populations as part of the EIA — No legal obli-
gation to consult the affected populations arises from the instruments invoked
by Argentina — Consultation by Uruguay of the affected populations did indeed
take place.

Production technology used in the Orion (Botnia) mill — No evidence to sup-

port Argentina’s claim that the Orion (Botnia) mill is not BAT-compliant in
terms of the discharges of efﬂuent for each tonne of pulp produced — From the
data collected after the start-up of the Orion (Botnia) mill, it does not appear
that the discharges from it have exceeded the prescribed limits.

Impact of the discharges on the quality of the waters of the river — Post-
operational monitoring — Dissolved oxygen — Phosphorus — Algal blooms —
Phenolic substances — Presence of nonylphenols in the river environment —
Dioxins and furans — Alleged breaches not established.
Effects on biodiversity — Insufﬁcient evidence to conclude that Uruguay
breached the obligation to protect the aquatic environment, including its fauna
and ﬂora.
Air pollution — Indirect pollution from deposits into the aquatic environ-

ment — Insufﬁcient evidence.
On the basis of the evidence submitted, no breach by Uruguay of Article 41 of
the 1975 Statute.
Continuing obligations: monitoring — Obligation of the Parties to enable
CARU to exercise on a continuous basis the powers conferred on it by the
1975 Statute — Obligation of Uruguay to continue monitoring the operation of
the Orion (Botnia) plant — Obligation of the Parties to continue their co-op-
eration through CARU.

*
Claims made by the Parties in their ﬁnal submissions.
Claims of Argentina — Breach of procedural obligations — Finding of

wrongful conduct and satisfaction — Forms of reparation other than compensa-
tion not excluded by the 1975 Statute — Restitution as a form of reparation
for injury — Deﬁnition — Limits — Form of reparation appropriate to the
injury suffered, taking into account the nature of the wrongful act — Restitution
in the form of the dismantling of the Orion (Botnia) mill not appropriate
where only breaches of procedural obligations have occurred — No breach
of substantive obligations and rejection of Argentina’s other claims — No
special circumstances requiring the ordering of assurances and guarantees
of non-repetition.

Uruguay’s request for conﬁrmation of its right to continue operating the
Orion (Botnia) plant — No practical signiﬁcance.

*

Obligation of the Parties to co-operate with each other, on the terms set out
in the 1975 Statute, to ensure the achievement of its object and purpose — Joint
action of the Parties through CARU and establishment of a real community of
interests and rights in the management of the River Uruguay and in the protec-
tion of its environment.

11 ARRÊT

Présents: M. T OMKA , vice-président, faisant fonction de président en l’affaire ;
MM. K OROMA ,A L-KHASAWNEH ,S IMMA,A BRAHAM ,K EIT,S EPÚLVEDA-
A MOR,B ENNOUNA,S KOTNIKOV,CANÇADO T RINDADE,YUSUF ,GREENWOOD ,
juges; MM. T ORRESB ERNÁRDEZ,V INUES, juges ad hoc; M. OUVREUR,
grefﬁer.

En l’affaire relative à des usines de pâte à papier sur le ﬂeuve Uruguay,
entre

la République argentine,

représentée par
S. Exc. M meSusana Ruiz Cerutti, ambassadeur, conseiller juridique du mi-
nistère des relations extérieures, du commerce international et du culte,

comme agent;
S. Exc. M. Horacio A. Basabe, ambassadeur, directeur général de l’Institut

du service extérieur de la nation, ancien conseiller juridique du ministère
des relations extérieures, du commerce international et du culte, membre
de la Cour permanente d’arbitrage,
S. Exc. M. Santos Goñi Marenco, ambassadeur de la République argentine
auprès du Royaume des Pays-Bas,

comme coagents;
M. Alain Pellet, professeur à l’Université de Paris Ouest, Nanterre-La
Défense, membre et ancien président de la Commission du droit interna-

tional, membre associé de l’Institut de droit international,
M. Philippe Sands, Q.C., professeur de droit international à l’University Col-
lege de Londres, avocat, Matrix Chambers (Londres),
M. Marcelo Kohen, professeur de droit international à l’Institut de hautes
études internationales et du développement de Genève, membre associé de
l’Institut de droit international,
me
M Laurence Boisson de Chazournes, professeur de droit international à
l’Université de Genève,
M. Alan Béraud, ministre à l’ambassade de la République argentine auprès
de l’Union européenne, ancien conseiller juridique du ministère des rela-
tions extérieures, du commerce international et du culte,
M. Daniel Müller, chercheur au Centre de droit international de Nanterre

(CEDIN), Université de Paris Ouest, Nanterre-La Défense,
comme conseils et avocats;

M. Homero Bibiloni, secrétaire d’Etat à l’environnement et au développe-
ment durable,
comme autorité gouvernementale;

M. Esteban Lyons, directeur national du contrôle environnemental du secré-
tariat à l’environnement et au développement durable,
M. Howard Wheater, docteur en hydrologie de l’Université de Bristol, pro-
fesseur d’hydrologie à l’Imperial College de Londres, directeur de l’Impe-
rial College Environment Forum,

12 JUDGMENT