The United States acknowledges “possible contaminants” near Lajes Air Base and says the health and safety of military personnel, their families and the surrounding Terceira community are among its highest priorities. More than two decades after contamination was identified, however, hydrocarbons remain present at monitored sites, Portugal insists remediation must continue, and uncertainty persists over how the environmental legacy should be understood.
Some histories remain above ground, preserved in buildings, photographs and memory. Others sink into the soil. At Lajes, where the American military presence has shaped generations of life on Terceira, one of the most difficult chapters of that long relationship lies beneath the surface—in contaminated land, groundwater monitoring wells and scientific reports whose technical vocabulary ultimately leads to a profoundly human question: what, if anything, has decades of military activity left behind in the environment surrounding the base?
Speaking to the Portuguese newspaper Expresso, a spokesperson for U.S. Air Forces in Europe acknowledged awareness of “potential concerns related to possible contaminants in the vicinity of Lajes Air Base.” The USAFE said those concerns are taken “very seriously” and described the health and safety of American military personnel, their families and the community surrounding the base as its highest priorities. The statement is significant against a history extending back to 2005, when contamination of soils and aquifers associated with the storage and handling of fuels and other pollutants by the U.S. Air Force was identified by the Americans themselves.
A new point of concern involves the designation NO-SIHHS—“No Substantial Impact to Human Health and Safety.” According to Expresso, American Air Force environmental specialists told Portugal’s National Laboratory for Civil Engineering (LNEC) in September 2025 that Lajes would again be classified under that designation. LNEC subsequently asked that such a decision be reconsidered. Asked by the newspaper whether the United States intends to reapply NO-SIHHS to Lajes, USAFE did not provide an answer. Portugal’s Ministry of Defense, meanwhile, has stated that the intention discussed verbally by American specialists at a September 11, 2025 meeting has not been formally communicated and insists that environmental mitigation work on Terceira has not been suspended.
The scientific picture requires careful reading. According to the latest LNEC findings cited in the report, monitoring at Site 3001 continues to detect accumulations of LNAPL—light non-aqueous phase liquids, pollutants such as petroleum products that can remain separate from groundwater—as well as hydrocarbon contamination in superficial and intermediate geological formations and in the basal aquifer. Some samples also contain polycyclic aromatic hydrocarbons above Portuguese reference thresholds, although below intervention values used in countries including Canada and the Netherlands. At Site 5001, concentrations measured downstream are described as relatively low, but contaminated areas remain within the site, including total petroleum hydrocarbons, BTEX compounds, polycyclic aromatic hydrocarbons and floating hydrocarbons.
There is, however, an equally important finding. Tests of water-supply wells have not detected hydrocarbon concentrations exceeding drinking-water quality standards. Traces of some volatile organic compounds and naphthalene have been found, but at concentrations below regulatory limits. This does not establish that drinking water is unsafe; on the contrary, the reported measurements remained within applicable standards. It does explain why continued monitoring is considered essential. Environmental surveillance is valuable precisely because contamination can be complex, uneven and capable of changing through movement in soil and groundwater.
Portugal’s Defense Ministry says it will continue defending implementation of LNEC’s technical recommendations, including remediation and decontamination wherever concentrations exceed admissible limits. Projects currently being carried out by USAFE with authorization from the Portuguese Ministry of Defense include soil rehabilitation and removal of contaminated earth in designated intervention areas. The unresolved issue, therefore, is not whether contamination has existed—it has been documented for years—but whether remediation, monitoring and classification adequately respond to what remains.
Another layer of concern comes from research by anthropologist Félix Rodrigues for a doctoral thesis presented at the University of Coimbra, which reported significantly higher concentrations of lead and other heavy metals in skeletal remains of former inhabitants of Praia da Vitória. That finding must be interpreted with particular caution. The study, as described, does not establish a causal relationship between those concentrations and cancer or other illnesses, nor does it by itself demonstrate that contamination from Lajes Air Base was responsible. It does, however, reinforce arguments for epidemiological research capable of investigating questions that have circulated within the community for decades.
Lajes has never been merely a military installation. It has been a workplace, an economic engine, a strategic Atlantic platform and a place of profound encounter between Azoreans and Americans. Families were sustained by the base; friendships crossed languages; generations grew up with American aircraft overhead and an American presence woven into the social history of Terceira. Precisely because that relationship has been so important, its environmental legacy deserves neither exaggeration nor minimization. It requires evidence, transparency, sustained remediation and the willingness of both countries to follow the science wherever it leads.
The deepest question is therefore not whether friendship between peoples can survive difficult truths. Mature friendships must be able to confront them.
For the communities surrounding Lajes, twenty years after contamination was first identified, reassurance matters. But reassurance is strongest when accompanied by measurements, remediation, independent science and continued public accountability.
The soil beneath an island remembers what has been placed into it. The responsibility of the present is to discover exactly what remains—and to ensure that future generations do not inherit what should have been cleaned away.
Based on a story in Diário Insular-José Lourenço, director. Photo by Jedgardo Vieira.