US threatens to pull plug on Lajes Air Base contamination clean-up, in spite of reports highlighting health risks

The United States has threatened to suspend environmental remediation work around the Lajes Air Base in the Azores once again, despite confidential Portuguese government reports warning that contamination from decades of military activity still poses environmental and potential public health risks.

According to a confidential 2025 report by Portugal’s National Laboratory for Civil Engineering (LNEC), obtained by Expresso, officials from the US Air Forces in Europe (USAFE) informed Portuguese counterparts during a videoconference on September 11, 2025, that they intended to reinstate a decision known as “NO-SIHHS” (“No Substantial Impact to Human Health and Safety”) – under which the US concludes that pollution around the base does not present a significant risk to people living or working nearby.

The position directly contradicts the assessment of Portuguese experts, who urged the Americans to reconsider after reviewing new evidence.

Environmental contamination linked to the US military presence at Lajes, on Terceira Island, has been documented since 2003, with polluted soils and groundwater attributed to fuel leaks and other military activities.

Although the US suspended remediation work between 2020 and 2022 after concluding the contamination posed no significant health threat, mitigation efforts later resumed. The latest US position raises the prospect of another halt, warns Expresso.

Portuguese experts warn contamination remains

LNEC’s report identifies continued hydrocarbon contamination in several areas around the base.

Near the main entrance, known as Porta de Armas, investigators found hydrocarbon concentrations exceeding Portuguese regulatory limits, although remaining below thresholds used in Canada and the Netherlands.

At the nearby South Tank Farm, home to large US fuel storage facilities, LNEC reported that while hydrocarbon contamination had become more localised during 2025, free fuel and high concentrations of pollutants remained in the ground.

The report describes it as “urgent” to prevent contaminants spreading into the nearby Paul da Praia da Vitória wetland.

The findings come as separate academic research, presented last week, detected heavy metals, including lead—substances associated with increased cancer risk—in the skeletal remains of people who had lived near the base.

As a result of this report, there is now pressure for a wider epidemiological investigation. The research author Félix Rodrigues has told Expresso he believes residents living close to the base should be examined to see a) whether they are carrying elevated concentrations of heavy metals in their bodies, and b) whether these findings correspond with the higher rates of cancer and other diseases in communities surrounding the base. (Cancers on Terceira Island, the home of Lajes Air Base, have been raising concerns for years, by dint of the fact that they are so much more commonplace than on other islands in the archipelago – islands that do not have a military air base, in other words).

Regional government rejects US assessment

Authorities in the Azores have said the latest American risk assessment is “too narrowly focused because it considers only exposure within military installations”, Expresso continues.

According to documents from the Azores Water and Waste Services Regulatory Authority (ERSARA), the US assessment fails to account for risks affecting the wider population living beyond the base perimeter.

The Regional Government concluded that Washington’s position “does not encompass the public health protection interests of Terceira Island as a whole.”

ERSARA also stated that the mere presence of hydrocarbons in groundwater is unacceptable, regardless of measured concentrations.

Although LNEC says the public drinking water supply currently complies with national safety standards, Portuguese authorities have recorded 36 groundwater samples exceeding hydrocarbon limits over the past decade.

A €5.3 million project is now under way to relocate water abstraction points in parts of Praia da Vitória to try and reduce long-term risks.

Portugal accuses US of withholding information

The dispute has been compounded by longstanding complaints that US authorities have failed to share information about remediation activities, Expresso adds.

A 2021 ERSARA document, also seen by the paper, said American officials did not voluntarily disclose details of environmental works and that Portuguese authorities had repeatedly needed diplomatic intervention to obtain information.

One example cited involved an undeclared borehole drilled near the runway in 2019. According to the report, the US Air Force failed to notify Portuguese authorities despite its own tests showing high hydrocarbon concentrations.

Portuguese officials have also complained that US representatives on the bilateral technical commission argue they have no legal obligation to decontaminate polluted sites located outside the military base, even where contamination originated from American operations.

Political row over health research

The controversy has also exposed divisions within Portugal’s governing coalition.

Portuguese Defence Minister Nuno Melo recently dismissed the recent doctoral research linking residents’ remains to potentially carcinogenic heavy metals – saying government policy should rely on assessments by certified public institutions rather than academic theses.

However, Artur Lima, leader of the Azores branch of the CDS party (the party led by Nuno Melo) and vice-president of the Regional Government, defended the research, noting that it had been funded by the Azores government, and assessed by the University of Coimbra.

Lima said the regional government would continue financing further doctoral research into contamination linked to Lajes.

This renewed disagreement comes at a sensitive time in US-Portuguese defence relations, with Washington maintaining around 170 personnel at Lajes Air Base following a major reduction in its military presence on Terceira a decade ago. There do appear to be plans to increase this military presence, but the environmental legacy of U.S. operations on Terceira Island remain one of the most contentious issues in bilateral relations -regardless of the fact that Nuno Melo has tried to belittle the situation.

Source: Expresso