The environmental and diplomatic tension between Argentina and Uruguay has returned to the scene with a new protagonist: a green hydrogen macro-plant and synthetic fuels The multinational HIF is planning a project in PaysandĂș, on the banks of the Uruguay River. The project, slated to become one of the largest energy investments in the region, has raised concerns in the Argentine province of Entre RĂos due to its potential impact on a shared ecosystem.
Given this scenario, the Argentina's Federal Justice system has taken a preventative stepA court in ConcepciĂłn del Uruguay has accepted an environmental damage lawsuit and ordered the preliminary collection of evidence to determine the potential transboundary impact of the project. This legal action inevitably brings to mind the conflict over the Botnia pulp mill, which ended up in the International Court of Justice and dominated the bilateral agenda of the RĂo de la Plata region for years.
Preventive demand and origin of the legal conflict
The case is being processed in the Federal Court of ConcepciĂłn del Uruguay, under the judge HernĂĄn ViriThe court decided to partially admit a preventive action for environmental damage filed by legislators from the Peronist party in Entre RĂos. The case, identified under file number 3276/2026, focuses on the potential consequences of the plant on the Uruguay River and its Argentine banks.
The driving force behind the lawsuit is the members of parliament. Guillermo Michel and Marianela Marclay and the senator Adam BahlAll representatives of the province of Entre RĂos. In their statement, they argue that the HIF Uruguay SA project could proceed without fully respecting the information and consultation obligations established in the Statute of the Uruguay River, the same international instrument that was central to the Botnia dispute before the International Court of Justice in The Hague in 2010.
According to the presentation, the installation of the plant in PaysandĂș could generate a âirreparable damageâ to the environment of the binational region if its impacts are not properly and jointly assessed. Therefore, legislators are calling for early judicial action to prevent any negative consequences from becoming difficult to reverse once the project is underway.
The magistrate took note of these arguments and framed his decision within the principles of Precaution and prevention in environmental lawThese rights are deeply rooted in both Argentine law and international agreements ratified by the country. According to Viri, the nature of the case demands swift action to protect fundamental rights related to a healthy environment before it is too late.
Judge's orders: reports, expert opinions and advance evidence
One of the most relevant aspects of the ruling is the authorization to produce early testThis procedural mechanism allows for the collection of information and technical evidence before the traditional evidentiary stage, which is crucial in environmental matters when data could be lost or become inaccessible over time or as a large-scale project progresses.
Specifically, the judge ordered that information be requested from several Uruguayan agencies. National Directorate of Environmental Quality and Assessment (Dinacea)The Ministry of Environment, which is under its jurisdiction, requested copies of the application for prior environmental authorization and the environmental impact study that HIF Global should have submitted as part of the national process.
He also asked the National Registry of Commerce of Uruguay data on the corporate structure of HIF Global and its subsidiaries, and to Central Bank of Uruguay Information on the ultimate beneficiaries of the companies involved. The aim is to have a clear picture of who is behind the project and under what corporate structures, an aspect that becomes relevant when investigating potential liability for environmental damage.
In parallel, the court ordered the intervention of the Administrative Commission of the Uruguay River (CARU)The binational body responsible for ensuring compliance with the River Statute was asked to report whether the project was formally communicated to the commission and whether the company submitted a transboundary environmental impact study, as required by the cooperation mechanisms stipulated in the agreement.
As a complement, Viri ordered the appointment of a professional expert biologistThe expert will be responsible for preparing a comprehensive environmental assessment. This specialist will analyze the points raised by the plaintiffs, from the potential impact on aquatic biodiversity to alterations in water quality or in ecosystems near the riverbank.
Scope of procedural measures and guarantees for the parties
The court ruling not only specifies what evidence will be presented, but also defines its scope. The court gave the green light to the documentary, informational and expert evidenceHowever, the court decided not to admit, at least for now, the testimonial evidence requested by the legislators. According to the ruling, the impossibility of producing testimonies at the appropriate procedural stage, as required by current regulations on anticipatory evidence, was not demonstrated.
In addition to the expert reports, the judge authorized the performance of a judicial recognition in the area where the green hydrogen plant is planned. This site visit will take place once the expert formally accepts the appointment and will allow for firsthand observation of the area's current conditions, its proximity to the river, and its relationship to protected natural spaces, such as the Queguay Islands.
The court also took into account the practical difficulties in notifying all the defendant parties, including the Uruguayan State and companies based in UruguayTo prevent the international complexity of the case from hindering preventive measures, the Public Defender's Office was involved, with the aim of guaranteeing the right to defense and the bilateral nature of the process without excessive delays.
At this point, the Argentine justice system operates on a delicate balance: on the one hand, it tries to ensure that the environmental and transparency standards These objectives are fulfilled in a high-impact project; on the other hand, it seeks not to unduly interfere in the sovereign decisions of the neighboring country, which makes coordination with Uruguay and with the CARU a key element.
The HIF project in PaysandĂș: scale, location and investment
The controversy revolves around the multinational's ambitious plan Global HIF to build a green hydrogen and synthetic fuels plant in the town of Constancia, in the Uruguayan department of PaysandĂș. The industrial complex would be located about three kilometers from the Argentine shore of ColĂłn, a location that has generated particular sensitivity among the communities on the Entre RĂos side of the river.
According to publicly presented figures, the project anticipates the production of around 880.000 tons of synthetic fuels per year Using green hydrogen at its maximum capacity, the estimated investment is around $5.385 billion in its final stage, which would make it one of the most significant economic projects in Uruguay's recent history.
The plant is projected to about 500 meters from the shore of the Uruguay River, near the Islas del Queguay Protected Area. This proximity to an environment of high ecological value and the industrial scale of the project fuel the fears of the Argentine plaintiffs, who are demanding rigorous studies on emissions, water use, possible spills and risks to fauna and flora.
From an energy perspective, HIF's proposal fits within the global trend towards green fuels and hydrogen as an energy carrierThis is an area where Europe, and the European Union in particular, is leading the way with ambitious decarbonization targets. It is no coincidence that projects of this kind are attracting the interest of international investors and companies involved in the energy transition.
However, European experience shows that even infrastructures considered âgreenâ can encounter strong local resistance if they are not managed transparently. environmental risks, citizen participation and the distribution of benefitsWhat is happening today in the Uruguay River basin is somewhat reminiscent of the debates taking place in various parts of Spain and the EU regarding large renewable energy installations, power evacuation lines, and hydrogen production plants.
Political reactions and relocation proposal
While the justice system continues to gather evidence, the political landscape has also shifted. The mayor of PaysandĂș, Nicolas OliveraHe held a meeting with the Uruguayan president, Yamandu Orsi, in which he put forward the alternative of relocate the plant within the department itself, in a location that helps to ease tensions with Argentina.
From Entre RĂos, the governor Rogelio Frigerio The Uruguayan governmentâwhich months earlier had hinted at the possibility of taking the case to the International Court of Justice in The Hagueâwas receptive to the idea of âârelocation, seeing it as a way to de-escalate the conflict without relinquishing environmental controls. For the authorities in Entre RĂos province, who feel directly affected by any changes to the Uruguay River, this political gesture from the Uruguayan side is a signal to be reckoned with.
For his part, Olivera emphasized that the Uruguayan government and local authorities are showing âsensitivityâ to environmental and logistical concernsAccording to the mayor, efforts are underway to ensure the plant is viable from an economic and technical standpoint, but also from a social and environmental one, and to prevent the project from becoming a permanent focus of diplomatic dispute.
In his statements, the head of the PaysandĂș department defended the need to find a âwin-winâ between investment and environmental protection. The idea is that all the project's externalitiesâfrom employment to ecological impactâare analyzed comprehensively, so that the final political decision leaves no loose ends on either side of the river.
Meanwhile, on the Argentinian side, the plaintiffs emphasize that the Federal Court's ruling is "fundamental for the defense of the Entre RĂos coasts of the Uruguay River"and that the measures ordered do not intend to cancel the development of clean energy in the region, but to channel it under clear rules and with the participation of all the actors concerned."
Regional dimension and parallels with Europe
Beyond this specific dispute, the case of the hydrogen plant in PaysandĂș is part of a broader discussion that is also being experienced intensely in Spain and other European countriesHow to promote large renewable energy projects without neglecting the protection of biodiversity, the rights of local communities and international commitments on shared waters.
In the European Union, the expansion of green hydrogen and synthetic fuels is being accompanied by the demand for strategic environmental assessmentsPublic consultations and cross-border cooperation mechanisms are necessary when infrastructure projects may affect more than one Member State. In this respect, the Statute of the Uruguay River and the CARU play a role in the Southern Cone comparable to that of certain EU frameworks in Europe.
What is happening on the Argentine-Uruguayan border also serves as a reminder for projects being planned in Europe, including those of direct interest to Spain, where there is increasing talk of possible hydrogen export corridors to northern Europe and large-scale production facilities. Latin American experience indicates that early coordination and transparency can prevent prolonged and costly conflicts.
For the European renewable energy industry, these types of cases act as a barometer of the growing importance of ESG criteria (environmental, social and governance) when it comes to financing projects. Investments of billions can be conditioned not only by their economic profitability, but also by the way they manage relationships with neighboring communities and countries.
In South America, as in the EU, a scenario is emerging in which large "green" developments will be subject to a increasingly intense legal and social scrutinyThe current controversy over the Uruguay River could become a landmark case study on how to reconcile energy transition, environmental law, and regional diplomacy.
Following the intervention of the Argentine justice system, the future of the green hydrogen plant in PaysandĂș is contingent upon a series of reports, expert analyses, and political decisions that must demonstrate that the largest planned investment in Uruguay It is fully compatible with the protection of the shared river and with the requirements of international law. What is at stake is not only strategic infrastructure for the energy transition, but also the capacity of the countries in the regionâand by extension, other areas such as Europeâto develop a model in which the promises of hydrogen and renewables go hand in hand with solid environmental safeguards and cross-border cooperation that meets current challenges.
