A new £1bn power station at Pembroke in Wales may be forced to have a new cooling system added after it emerged that its existing design may flout environmental laws, reports BBC Wales.
BBC Wales has seen a leaked document produced by the European Commission that formally notifies the UK Government that it has infringed four separate environmental laws on at least 18 occasions.
However, the plant's developers, RWE nPower say that the design and build of the station has been thoroughly scrutinised by regulators.
Pembroke is a gas-fired station, capable of producing 2,000 MWe via liquid natural gas imported into Milford Haven from Qatar. It officially opened in September 2012.
Now the EU wants assurances from the UK Government that the technology used in the production and running of the plant will not adversely affect local residents in the Pembrokeshire area.
Joe Hennon is the environmental spokesman for the EU Commission.
"The cooling system that they're using in this plant is what we're really concerned about," he said.
"It raises the temperature of the water by about eight degrees when it comes out into the estuary, and it takes in potentially millions of fish and other forms of life and they inject biocides into the water as well," he added.
The Commission believes the UK should have conducted a thorough environmental impact assessment, especially as the power station is built in a special conservation area.
The Welsh Government had previously commissioned a report from its own advisors, the Countryside Council for Wales that had concluded the plant could jeopardise local marine life before it was ever built. These concerns seem to have been ignored, and now have resurfaced.
Whilst the owners of the plant insist that it complies with all relevant legislation, the EU Commission believes that corners were cut in the selection of the cooling system, the UK opting for the cheapest system that causes the greatest damage to wildlife.
It is estimated that at full capacity the cooling system could suck up 1 million adult fish every three weeks, with a 100% mortality rate.
Pembroke power station may breach eco law (BBC News)