The EC said on Thursday that there has been no reduction in nitrogen oxide emissions from the RWE-owned coal plant since it warned the UK in October last year that it had two months to bring emissions levels down.
The Wales-based coal-fired power station emits more than double the allowable emissions under its large combustion plant directive at 1,200mg/Nm3 compared to the limit of 500mg/Nm3, which has been in force since 1 January 2008.
The Commission first raised its concerns in a letter of formal notice in June 2013, and followed this up with a second warning in October 2014.
RWE said last year that it would move forward with plans to update the plant with a new £12 million boiler in middle of this year and is considering the installation of a further two boilers within the next four years.
The Commission said that although it welcomes the investments due to be made to upgrade the plant, “at present the plant continues to operate under a permit which allows it to emit high levels of the toxic gas NOx”.
“The Commission is therefore referring this case to court,” it said.
Initially the UK was granted a relaxation of emissions rules to allow Aberthaw to burn locally mined coal, which is more difficult to ignite than other types of coal due to its low proportion of volatile matter.
But the EC is now challenging the interpretation of that provision, saying it was meant to apply only to coal with less than 10 per cent volatile matter. Aberthaw’s feedstock has between 6 and 15 per cent volatile content.