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.
1. The “understanding” of 2 March 2004 between Argentina and Uruguay
125. The Court recalls that, after the issuing of the initial environmental authorization to
CMB by Uruguay, without CARU having been able to carry out the functions assigned to it in this
context by the 1975 Statute, the Foreign Ministers of the Parties agreed on 2 March 2004 on the
procedure to be followed, as described in the minutes of the extraordinary 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 Ministros 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 construcción 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 discrepancies 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 information on the construction of the mill and
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that, in terms of the operational 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 Uruguay 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 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 procedure laid down
in Article 7 of the 1975 Statute. Lastly, Uruguay maintains 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 Subcommittee
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
127. Argentina, for its part, maintains that the “understanding” between the two Ministers of
2 March 2004 was intended to ensure compliance 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 contemplated 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 “understanding” 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 “understanding” 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 the procedure for
communicating information provided for by the “understanding” would, if applied, replace that
provided for by the 1975 Statute. Be that as it may, such replacement was dependent on Uruguay
complying with the procedure laid down in the “understanding”.
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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 contention that the “understanding” put an end to its dispute with Argentina in respect
of the CMB (ENCE) mill, concerning implementation of the procedure 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 “understanding”, only if Uruguay had complied with the terms of the
“understanding”. 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 paragraph 40 above), the Foreign Ministries of the
two States issued a press release on 31 May 2005 announcing the creation of the High-Level
Technical 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 Technical 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.
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 cellulose 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.
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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 meeting 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 negotiations are ongoing. It acknowledges that, under
international law, the initiating 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 carried 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 construction 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 sees it as for the Court to
pronounce on all the breaches of the 1975 Statute, 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, during 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
Lastly, Argentina rejects Uruguay’s claim that the work on the foundations of the Orion
(Botnia) mill, its chimney and the port was merely preliminary in nature and cannot be regarded as
the beginning of construction 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 Article 60 of the 1975 Statute. While it is true that Article 12 provides for
recourse to the procedure indicated in Chapter XV, should the negotiations 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.
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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
constructed in the Eastern Republic of Uruguay could have on the ecosystem of the shared
Uruguay River, with “the group [having] to produce an initial 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 negotiations 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
“which aspects of the work or the 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
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 operation of a treaty”, including, according to the International Law
Commission’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 provisions 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
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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 construction 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 activities before having applied
the procedures laid down by the “joint machinery 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 Article 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 procedural mechanism for
co-operation between the parties to prevent significant 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 principle 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 essential to
co-operation between States. The Court recalled in the cases concerning Nuclear Tests
(Australia v. France) and Nuclear Tests (New Zealand v. France):
“One of the basic principles governing the creation and performance 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 characteristics 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-operation 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
148. In this respect, contrary to what Uruguay claims, the preliminary work on the pulp mills
on sites approved by Uruguay alone does not constitute an exception. This work does in fact form
an integral part of the construction of the planned mills (see paragraphs 39 and 42 above).
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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
Fray 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 obligation 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 provided 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 agreement 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 Justice.
In the cases referred to in Articles 58 and 59, either party may submit 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 consider there to be a “no construction obligation”
borne by the State initiating 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 development 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, reference 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 interests of
the State likely to be affected in case it decides to authorize the activity to be pursued . . .”.
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
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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 obligations under Chapter II of the
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 Articles 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 Statute does not provide for the Court, to which
the matter would be submitted 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 concerning 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, following 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 those rights include
that of implementing the project, on the sole responsibility 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. Uruguay), 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 compliance with the 1975 Statute.
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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 determined 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 obligations 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. SUBSTANTIVE OBLIGATIONS
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 Uruguay for it to establish that the Orion (Botnia)
mill will not cause significant 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
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 position about transferring the burden of proof to Uruguay were correct, it would
make no difference given the manifest weakness of Argentina’s case 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), Judgment of
3 February 2009, para. 68; Sovereignty over Pedra Branca/Pulau Batu Puteh, Middle Rocks and
South Ledge (Malaysia/ Singapore), Judgment of 23 May 2008, para. 45; Application of the
Convention on the Prevention and Punishment of the Crime of Genocide (Bosnia and
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Herzegovina v. Serbia and Montenegro), Judgment, I.C.J. Reports 2007, 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 before the Court as counsel for one or the other of the Parties to provide 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,
conflicting 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”.
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167. The Court has given most careful attention to the material submitted to it by the Parties,
as will be shown in its consideration of the evidence below with respect to alleged violations of
substantive obligations. Regarding those experts who appeared before it as counsel at the hearings,
the Court would have found it more useful had they been presented 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
counsel, 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 documents 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 complexity 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
considered 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 presented 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 international 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 failing to co-ordinate with Argentina on measures
necessary to avoid ecological 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,
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172. The Parties also disagree on the scope and implications of Article 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 Chapter 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 environment and the joint management of this shared
resource. This objective 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 embodying 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 utilization may be viewed as the
cornerstone of the system of co-operation established in the 1975 Statute and the joint machinery
set up to implement 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
construction and operation of the Orion (Botnia) mill in the light of those provisions 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 substantive
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 functions 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 formulation 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 obligations arising from Articles 7 to 12 of the 1975 Statute which
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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 or 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
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. Article 35 of the 1975 Statute provides that the parties:
“undertake to adopt the necessary measures to ensure that the management 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
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 management 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 deleterious 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 ecological balance
181. Argentina contends that Uruguay has breached Article 36 of the 1975 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, provides 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.
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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-operation, 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 concludes that it has not acted in breach of Article 36 of the
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 Statute 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 Section 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 Gabčíkovo-Nagymaros case:
“in the field of environmental protection, vigilance and prevention are required on
account of the often irreversible character of damage to the environment and of the
limitations inherent in the very mechanism of reparation of this type of damage”
(Gabčíkovo-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 obligation 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
187. The Court considers that the obligation laid down in Article 36 is addressed to both
Parties and prescribes the specific conduct of co-ordinating the necessary measures through the
Commission to avoid changes to the ecological balance. An obligation to adopt regulatory or
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administrative measures either individually or jointly and to enforce them is an obligation of
conduct. Both Parties are therefore called upon, under Article 36, to exercise due diligence in
acting through the Commission for the necessary measures to preserve the ecological balance of the
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 provision.
4. The obligation to prevent pollution and preserve the aquatic environment (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 particular, to prevent its
pollution, by prescribing appropriate rules and [adopting appropriate] measures in
accordance with applicable international agreements and in keeping, where
relevant, with the guidelines and recommendations of international technical
(b) not to reduce in their respective legal systems:
1. the technical requirements in force for preventing water pollution, 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
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 agreements, including the
Biodiversity Convention and the Ramsar Convention. It maintains that the 1975 Statute prohibits
any pollution which is prejudicial to the protection and preservation of the aquatic environment or
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which alters the ecological balance of the river. Argentina further argues that the obligation to
prevent pollution of the river is an obligation of result and extends not only to protecting the
aquatic environment proper, but also to any reasonable and legitimate use of the river, including
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 prohibition on all discharges into the river. It is only
those that exceed the standards 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
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 environment 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 Opinion,
I.C.J. Reports 1996 (I), pp. 241-242, para. 29.)
194. The Court moreover had occasion to stress, in the Gabčíkovo-Nagymaros Project case,
that “the Parties together should look afresh at the effects on the environment of the operation of
the Gabčíkovo power plant” (Gabčíkovo-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 addressing
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 Article 56 of the Statute, and the obligation it imposes on the Parties to adopt rules
and measures individually to “protect and preserve the aquatic environment 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 respective 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.
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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
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 appropriate rules and measures, but
also a certain level of vigilance in their enforcement and the exercise of administrative control
applicable to public 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 rules 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 agreements 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 I, Section. 2, Article 1 (c) of the Digest (E3)).
199. The Digest expresses the will of the Parties and their interpretation 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
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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, Chap. 5, Sec. 1, Art. 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 industrial discharges in a decree
that also recognizes the binding effect of the CARU 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 reduction in case the
standard values adopted for the different legitimate uses of the River’s water are
(d) to promote scientific research on pollution.” (Title I, Chap. 2, Sec. 1, Art. 1.)
202. The standards laid down in the Digest are not, however, exhaustive. 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.
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(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 Statute. 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 environmental 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 particular
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 Economic
Commission for Europe (hereinafter the “Espoo Convention”) (UNTS, Vol. 1989, p. 309), and the
1987 Goals and Principles of Environmental Impact Assessment of the United Nations
Environment Programme (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
assessment of the Orion (Botnia) mill was necessary, but argues that international 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 properly 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 aquatic environment with respect to activities which may be liable to
cause transboundary harm, carry out an environmental impact assessment. 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 evolving, 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. Nicaragua), Judgment of
13 July 2009, 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
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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 arguments, 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. Moreover, 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 indication 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 operations have started and, where necessary,
throughout the life of the project, continuous monitoring of its effects on the environment shall be
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 environmental impact assessment is
inadequate is that it contains no analysis of alternatives 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”.
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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 circumstances to do so. Finally,
Uruguay affirms that in any case it did so and that the suitability of the Orion (Botnia) site was
209. The Court will now consider, first, whether Uruguay failed to exercise due diligence in
conducting the environmental impact assessment, particularly with respect to the choice of the
location of the plant and, 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
paragraph 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 possible 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 choosing Fray
Bentos. The evaluations concluded that the limited amount of fresh water in La Paloma and its
importance as a habitat for birds rendered it unsuitable, while for Nueva Palmira its consideration
was discouraged 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.
Consequently, the Court is not convinced by Argentina’s argument that an assessment of possible
sites was not carried out prior to the determination 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 Uruguay 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
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 geomorphological 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
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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 “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, calibration 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 frequently 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 standards 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 hydrological characteristics of the river and the capacity of its waters to disperse and dilute
different types of discharges. The Court is of the opinion that, should such inadequacy be detected,
particularly with respect to certain 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 capable 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 international law imposes specific obligations on States in this regard. In
support of this argument, Argentina points to Articles 2.6 and 3.8 of the 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.
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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 the granting of the initial
environmental authorization, Uruguay did undertake 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
“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; electromagnetic and electrostatic emissions; [and] liquid discharges into
Inhabitants of Fray Bentos and nearby regions of Uruguay and Argentina 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.
(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 available 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 international standards, in the light of the various techniques available for producing 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.
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221. Argentina, however, specifically criticizes the absence of any “tertiary 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 effluent 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 considers 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
by the industrial plant to be established, particularly in a sector such as pulp manufacturing, which
often involves the use or production of substances 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 regulatory
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 Pollution 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 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
regulations of the Parties in terms of the concentration of effluents per litre of wastewater
discharged from the plant and the absolute amount of effluents that can be discharged in a day.
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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. However, the Court notes that Argentina has itself generated much factual information
and that the materials which Uruguay produced have been 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 characterized 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 contention 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 relevant
Uruguayan regulation as characterized by the Court in paragraph 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,
measurements 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
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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 environmental 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 quality, air quality, phytoplankton and zooplankton of
the river, health indicators 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 belonging 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 inadequate 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 monitoring 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
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two national universities, contracted by the National Secretariat of Environment 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 Ñandubaysal Bay and Inés Lagoon, the data from which,
according to Argentina’s counsel, “enabled the scientists to clearly set the bay apart, as it acts as an
ecosystem that is relatively detached from the Uruguay river” (Scientific and Technical Report,
Chap. 3, appendix: “Background Biogeochemical Studies”, para. 4.1.2; see also ibid,
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 Uruguayan 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 themselves 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 controversy 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 river 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
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beneficial and there is a CARU standard which sets a minimum level of dissolved 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
constitutes 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.,
dissolved 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
239. The Court observes that a post-operational average value of 3.8 mg/L for dissolved
oxygen would indeed, if proven, constitute a violation 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, Chap. 4, Sec. 2). However, the Court finds that the allegation 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 samples
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 are above the CARU
minimum and are the same upstream and downstream. 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 “dissolved oxygen”.
240. There is agreement between the Parties that total phosphorus levels 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 proceedings. 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).
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241. A major disagreement between the Parties relates to the relationship 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 attributability of these concentrations as well as the
eutrophication to the operation 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 phosphorus. The Court will therefore have to use the water quality and effluent
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 accordance 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 Water Quality). The Uruguayan Decree
also establishes a total phosphorus discharge standard of 5 mg/L (ibid., 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 discharge from the plant. Moreover,
according to the DINAMA 2009 Emissions 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 values much below the standard established under the Uruguayan Decree.
244. The Court observes in this connection that as early as 11 February 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, constitute 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 untreated sewage of a city of 65,000 people.” (P. 20, para. 6.1.)
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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 insignificant by the company. Nevertheless,
considering that the parameters 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 consideration, it is understood
that the waste disposal proposed in the project may be accepted, as long as there is
compensation for any increase over and above the standard value for any of the critical
parameters.” (Ibid., p. 21.)
246. The Court further notes that the initial environmental authorization, granted on
15 February 2005, required compliance by Botnia with those conditions, with CARU standards and
with best available techniques 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 November 2007. On 29 April 2008, Botnia and the OSE concluded an
Agreement 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 discharge 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 compensation.
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 various 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
cyanobacteria, 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 (Botnia) 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 Argentine 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.
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250. The Parties are in agreement on several points regarding the algal bloom of
4 February 2009, including the fact that the concentrations of nutrients 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 interdependence 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 operating, 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. 220.127.116.11 and App. 1, showing
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 increase 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 emitted, nonylphenols and
thus has caused damage to, or at least has substantially put at risk, the river environment.
According to Argentina, the most likely source of these emissions are surfactants (detergents),
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nonylphenolethoxylates 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
determined 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 containing 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 the 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 Ñandubaysal 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.
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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 obligation 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 maintains 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 Farrapos site, situated “in the lower
section of the River . . . downstream from the Salto Grande dam and on the frontier with
Argentina”, a few kilometres 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 Farrapos was not included in the list of Ramsar sites whose ecological character 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 preserve 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
undertakings 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 Uruguay breached its obligation to preserve the aquatic environment including the
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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 environment” in violation of Article 41 of the
1975 Statute. Argentina also argues that the 1975 Statute was concluded not only to protect the
quality 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 findings 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 Statute, 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 Uruguayan
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.
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V. THE CLAIMS MADE BY THE PARTIES IN THEIR FINAL SUBMISSIONS
267. Having concluded that Uruguay breached its procedural obligations 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 violated 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
internationally wrongful acts.
269. The Court considers that its finding of wrongful conduct by Uruguay 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 Statute 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, Argentina
contends that Uruguay is under an obligation to “re-establish on the ground and in legal terms the
situation that existed before [the] internationally 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 materially 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 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 inapplicable in the present case, since they
establish a régime of responsibility in the absence of any wrongful act.
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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 appropriate 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 disproportionate 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 reparation 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
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 materially
impossible or involves a burden out of all proportion to the benefit deriving from it, reparation
takes the form of compensation or satisfaction, or even both (see Gabčíkovo-Nagymaros Project
(Hungary/Slovakia), Judgment, 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, p. 233, para. 460; see also Articles 34 to 37 of the International
Law Commission Articles on the Responsibility 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), Judgment,
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
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negotiation. The Court has however observed that construction of that mill began before
negotiations had come to an end, in breach of the procedural obligations laid down in the
1975 Statute. Further, as the Court has found, on the evidence submitted to it, the operation of the
Orion (Botnia) mill has not resulted in the breach of substantive obligations laid down in the
1975 Statute (paragraphs 180, 189 and 265 above). As Uruguay was not barred from proceeding
with the construction and operation 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 procedural obligations.
276. As Uruguay has not breached substantive obligations arising under the 1975 Statute, the
Court is likewise unable, for the same reasons, to uphold Argentina’s claim in respect of
compensation for alleged injuries suffered in various economic sectors, specifically tourism and
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 Chapter II of
278. The Court fails to see any special circumstances in the present case requiring the
ordering of a measure such as that sought by Argentina. 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 presumed (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 of
13 July 2009, 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.
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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 practical significance, since Argentina’s claims in
relation to breaches by Uruguay 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 obligation 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-operation 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 environment. They have also co-ordinated their
actions through the joint mechanism of CARU, in conformity with the provisions of the
1975 Statute, and found appropriate solutions to their differences within its framework 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,
(1) By thirteen votes to one,
Finds that the Eastern Republic of Uruguay has breached its procedural 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, Skotnikov, Cançado Trindade,
Yusuf, Greenwood; Judge ad hoc Vinuesa;
AGAINST: Judge ad hoc Torres Bernárdez;
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(2) By eleven votes to three,
Finds that the Eastern Republic of Uruguay has not breached its substantive obligations
under Articles 35, 36 and 41 of the 1975 Statute of the River Uruguay;
IN FAVOUR: Vice-President Tomka, Acting President; Judges Koroma, Abraham, Keith,
Sepúlveda-Amor, Bennouna, Skotnikov, Cançado Trindade, Yusuf, Greenwood;
Judge ad hoc Torres Bernárdez;
AGAINST: Judges Al-Khasawneh, Simma; Judge ad hoc Vinuesa;
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) Peter TOMKA,
(Signed) Philippe COUVREUR,
Judges AL-KHASAWNEH and SIMMA append a joint dissenting opinion to the Judgment of
the Court; Judge KEITH appends a separate opinion to the Judgment of the Court;
Judge SKOTNIKOV appends a declaration to the Judgment of the Court;
Judge CANÇADO TRINDADE appends a separate opinion to the Judgment of the Court;
Judge YUSUF appends a declaration to the Judgment of the Court; Judge GREENWOOD appends a
separate opinion to the Judgment of the Court; Judge ad hoc TORRES BERNÁRDEZ appends a
separate opinion to the Judgment of the Court; Judge ad hoc VINUESA appends a dissenting
opinion to the Judgment of the Court.
(Initialled) P. T.
(Initialled) Ph. C.
Por mayoria, Uruguay no cumplio con el Tratado del Rio Uruguay, (la minoria opino que si cumplio).
Por unainimidad: no se desmantelan las plantas.
Por unainimidad: tienen que colaborar para controlar para que no polucionen.
Hay dos votos aparte, que son distintos y no tengo los fundamentos.