‘A ticking environmental time bomb’: What lies beneath Aughinish Alumina

The most striking feature of the area around the Aughinish Alumina plant is its vast fields of red mud – formally known as the “bauxite residue disposal area” – surrounding the Co Limerick facility.This is where the plant dumps waste products from the alumina production process. In the four decades of the refinery’s operation next to Foynes, about 40 million tonnes of the highly alkaline sludge has accumulated in the area.For years campaigners have railed against the red mud pile. Farmers blame dust from the open-air disposal area for poisoning their animals. Environmental groups such as An Taisce fear a breach in the barriers containing the red mud could result in the ecological devastation of the Shannon estuary on which the plant sits.But underneath the red mud area, hidden from view, is, according to some experts, a more immediate threat: a highly contaminated body of water sitting on top of porous limestone rock.READ MOREThis contamination arises from the process used to transform bauxite – a type of rock imported from South America and Africa – into alumina that is used to make aluminium. An Irish Times investigation has found that more than half of all groundwater sources at Aughinish Alumina in Co Limerick are currently in breach of Irish and EU contamination limits, the direct result of the plant’s production process.The data provided by the company itself to the Environmental Protection Agency consistently shows extremely high levels of aluminium, arsenic and other hazardous materials in monitoring wells and streams around the 530-hectare plant.The Irish Times analysed these publicly available monitoring reports submitted to the Environmental Protection Agency (EPA) going back to 2021, along with inspection reports, annual environmental reports and analyses by engineering firms commissioned by the plant.A satellite image of the Aughinish Alumina plant in Co Limerick shows the so-called 'red mud' waste adjacent to the site, on the Shannon estuary. Photograph: Google Earth Independent experts also reviewed this data for The Irish Times and shared their conclusions as part of the investigation.The Russian-owned facility has come under intense scrutiny over recent months due to its exports of alumina to Russia and links to companies supplying Moscow’s arms industry.It is adjacent to the Shannon estuary, a nature reserve and a local national school, along with many farms. It is also a few hundred metres from the Foynes Water Treatment Plant, which provides drinking water to the local area.In various reports, Aughinish points to monitoring data showing its contaminated water is not escaping the boundaries of the plant. However, environmental campaigners fear polluted water could be escaping unnoticed through the porous limestone bedrock, known as karst.“If you have a plant that’s built on karst that is leaking contaminants into the karst, you could just about guarantee those contaminants are leaving the site,” said Steven Emerman, a geophysicist specialising in groundwater analysis.“The location of these kinds of mines or industrial sites on karst is really problematic. That is usually something that people try to avoid.”Soil layers Aughinish Aughinish, which is the largest alumina refinery in Europe, is owned by the Russian metals giant Rusal. The plant’s environmental credentials, which include boasting the “best semi-natural grasslands in Ireland”, feature prominently on Rusal’s website.But problems with Aughinish’s groundwater have persisted for many years, environmental reports show. The entrance to the Aughinish Alumina plant, which is owned by the Russian metals giant Rusal. Photograph: Niall Carson/PA One of the worst periods of contamination in recent years occurred in late 2024 when 60 per cent of wells and streams were in breach of EU limits, according to Aughinish’s monitoring data provided to the EPA.An improvement scheme to mitigate the pollution has recently started to show limited success but, in some areas, contamination has got much worse, monitoring data for the first three months of this year shows.Despite this, Aughinish has faced no sanctions from the EPA over the state of its groundwater.Over the years, the plant has drilled dozens of observation wells around the site to monitor pollution levels. Sixteen “estuarine streams” that flow from the site out to the Shannon are also monitored.Analysis of Aughinish’s data shows some of these water sources contain extremely high levels of hazardous materials. For example, in Plant Observation Well 17 (POW 17), located on the east of the refinery, aluminium levels were more than 4,700 times the EU limit when the most recent available readings were taken earlier this year.In Observation Well 10, in the red mud area, zinc levels reached 125 times safe limits in late 2025, according to the data.[ From the Shannon to Siberia: How alumina from a Limerick refinery enters Russia’s weapons supply chainOpens in new window ]Over the years, local farmers and environmental campaigners have blamed alleged leakage of heavy metals such as aluminium and nickel for abnormal levels of cattle deaths in the surrounding areas. These allegations are denied by the plant.A lengthy investigation by the EPA in the mid-1990s cleared the plant and attributed the deaths to poor farming practices.Another pollutant, arsenic, is also a matter of serious concern. The substance, which is highly toxic to humans and animals, was found at unsafe levels in 12 observation wells located around the refinery this year, according to the company’s monitoring data analysed by The Irish Times. Farmers have blamed alleged leakage of heavy metals for abnormal levels of cattle deaths in the surrounding areas. These allegations are denied by the plant. Photograph: Nick Bradshaw “This is not what would generally be considered normal for a well-managed alumina refinery,” said Emerman, who has been commissioned by environmental charity An Taisce to carry out an in-depth analysis of the plant’s groundwater.The same monitoring data shows that in early 2024, one of the wells, POW 7, contained arsenic levels 129 times EU limits. “That’s really quite high. That’s a very dangerous level,” he said.Like the red mud, much of the water under the plant is also extremely alkaline, the data shows.Alkalinity is measured on the pH scale, with 14 being the maximum. Water with a pH above 11 is considered corrosive to organic material. In tests conducted in 2026, five observation wells had pH levels above 11, with one reaching 13 on the scale.As part of efforts to address the pollution, Aughinish tests more than 80 water sources around the plant four times a year and provides the results to the EPA. The water quality reports were then compared to EU groundwater safety limits adopted into Irish law in 2016.Of the 82 monitoring wells and streams examined in 2026, 44 – or 54 per cent – were in breach of groundwater threshold values set by the EU. This included seven of the nine active streams intersecting the plant.In various monitoring reports, the EPA has noted the presence of highly contaminated groundwater on the site. A report written after an inspection in August last year stated the site is “a significant pressure on the groundwater body”. It also noted that, although a general “downward trend was observed”, there was also contamination in some “estuarine streams”, one of the ways groundwater leaves the plant area. Overall, the EPA describes water quality at the plant as “poor”.To actually accept that water is 100 times the groundwater limits isn’t environmental protection – it’s environmental destruction— Kieran BurnsAughinish currently operates under an “industrial emissions licence” issued by the EPA that states the plant must work towards the elimination of groundwater contamination. A previous version of the licence, last issued in 2012, was more explicit. It stated: “No potentially polluting substance shall be permitted to discharge to groundwater under the site.”Despite all of this, the EPA has made no findings of noncompliance against Aughinish in recent years over the contamination of groundwater. Instead, it has told Aughinish to lay out a timeline for achieving groundwater contamination levels that are less than 100 times the EU limits.“This is like a cop stopping you for drink driving and allowing you to continue your journey even though you are 100 times over the limit,” said Kieran Burns, an accountant who was previously the European finance manager for the American aluminium giant Alcoa. He described the Limerick plant as a “ticking environmental time bomb”.“To actually accept that water is 100 times the groundwater limits isn’t environmental protection – it’s environmental destruction.”Burns described working at Alcoa’s now-shuttered alumina plant in Germany and having to prove “that there was no toxicity in the groundwater and that there was no seepage anywhere”.“And this was 1985,” he said.Water was pumped into pools “that were so clean they had goldfish in them”, he said.Aughinish is the largest alumina refinery in Europe. Photograph: Niall Carson/PA Michelle Hayes, a Limerick solicitor and environmental campaigner, said the situation at the Aughinish plant was “not acceptable”.Hayes is the president of Environmental Trust Ireland, which recently won a High Court case blocking an expansion of Aughinish’s red mud area. She accused the EPA of “permitting noncompliance” over Aughinish.“There’s EU directives on this and they have to comply with these levels, but they’re just being allowed not comply by the EPA.”For campaigners, the perception that the EPA is soft on Aughinish is based, in part, on a history of light-touch regulation by authorities towards the plant. The last case of significance taken by the EPA against the plant was in 2002 when 500,000 litres of sodium aluminate and sodium hydroxide – chemical compounds from the industrial process – leaked from Aughinish into the Shannon.The plant, which was then under the ownership of the Swiss conglomerate Glencore, failed to notify the EPA for 15 hours after the highly toxic material entered the river. The company was fined €1,270, the maximum allowed by law at the time.Since then, the EPA has issued multiple notices to the plant stating it is not in compliance with its environmental licence under various headings, including seven since 2020. However, none related to groundwater and no sanctions were issued in any case. [ Rules to protect Ireland’s fragile rivers are being repeatedly breachedOpens in new window ]In previous years, the officials have granted Aughinish various exemptions from environmental standards, including easing the terms of a pollution control licence in 2004. “It shows for me a weakness on the part of the EPA,” then Green Party leader Trevor Sargent said at the time.“Is the EPA acting as an environmental protection agency or not? Or is it just acting as a licensing agency?” asked Hayes. 'Aughinish talks about a groundwater divide. There’s no such thing as a groundwater divide,' says Limerick solicitor and environmental campaigner Michelle Hayes. Photograph: Nick Bradshaw Aughinish is in the process of applying for a new industrial emissions licence from the EPA. In its submission to the approval process this month, An Taisce raised concerns about groundwater contamination.It noted that EU rules state the groundwater status in the area must be improved from “poor” to “good” by next year. “Yet these statuses have remained unchanged since 2021,” the charity wrote.It also raised concerns there has been no monitoring for arsenic levels in the local population since blood samples were taken during the EPA investigation in the 1990s. These blood samples subsequently went missing, An Taisce noted.Studies have been done showing these things can travel a long, long way in groundwater. There is no safe level— Michelle HayesVarious reports commissioned by Aughinish and the EPA describe the contamination of the groundwater as a “plume” that originates out from the centre of the facility to water sources around the site.The pollutants travel through fissures located throughout the bedrock. The porous nature of this bedrock means seepage of hazardous water remains a constant hazard. A water quality assessment submitted by Aughinish this year lists several methods the company uses to prevent contaminated water seeping into the wider area, including pumping water from streams back into the centre of the plant for treatment.In recent years, as part of a “corrective action plan” agreed with the EPA, Aughinish has built a new series of wells, called groundwater wells, both to monitor the extent of the plume and contain its spread.[ Aughinish Alumina will have to prove its products are not supplying Russian armyOpens in new window ]According to the latest assessment commissioned by Aughinish, this is having a broadly positive impact, with some wells showing a reduction in contamination in 2025 and 2026.In response to queries, Aughinish Alumina said it is “committed to operating to the highest environmental standards while continuously investing in measures to improve environmental performance”.It said the EPA-approved monitoring system “confirms that there is no impact beyond the boundary of the facility” and that it is engaged in a corrective action plan to contain the contaminated groundwater which is continuing to improve water quality across the site.However, analysis of samples from the 10 new groundwater wells also shows the extent of the challenge the plant faces. In mid-2024, Groundwater Well 5 recorded aluminium levels 5,745 times safe limits and a pH of nearly 13. Late last year, Groundwater Well 1 recorded arsenic levels that were 253 times EU limits.The data also shows that, although some wells have improved in quality recently, six have become far more contaminated. This includes POW 17, which roughly doubled in aluminium and arsenic levels between 2025 and 2026, and POW 20, where aluminium levels rose by almost 500 per cent.In response to queries, an EPA spokeswoman acknowledged “residual losses of caustic liquors have occurred in the processing area, resulting in elevated pH, aluminium and soda concentrations in groundwater in that area”.This contributes to the site being designated a “significant pressure” zone, she said.However, she said the plant was engaging in extensive remedial work, including installing pumping stations in the streams to prevent contaminated water leaving the plant.The agency said there was no evidence of a “significant groundwater plume migrating off-site” leaving the red mud site area, and that the risk to the surrounding area was considered “low”.“While contamination remains present in parts of the plant processing area, particularly elevated pH and aluminium in some monitoring wells, the overall trend indicates generally stable conditions in the groundwater,” the EPA said.It said groundwater threshold values were designed to serve as “assessment and remediation targets” and not as representing “natural unpolluted groundwater conditions”.The EPA added that there was “no evidence” that any material from Aughinish Alumina has harmed animals or humans.Emerman said groundwater contamination was an issue that can persist for decades and that current contamination “does not, by itself, prove that the refinery is currently being poorly operated”. But he said the data suggested the plant’s environmental controls “have not been fully effective at preventing groundwater contamination”.For environmental campaigners, the porous nature of the bedrock means, even with mitigation measures, toxic water could still leak into the surrounding land and river.[ Pussy Riot’s Maria Alyokhina has a warning for Ireland and the rest of EuropeOpens in new window ]“Aughinish talks about a groundwater divide. There’s no such thing as a groundwater divide,” said Hayes, the Limerick solicitor and environmental campaigner.“Studies have been done showing these things can travel a long, long way in groundwater. There is no safe level.”“Your ability to contain contaminated water in a karstic region would be regarded as highly problematic really under any circumstances,” said Emerman, the geophysicist.Placing sites such as Aughinish on porous limestone and next to large waterbodies is extremely risky, he added. “We just don’t do that any more,” he says.