Welsh Water has been fined a six-figure sum after pleading guilty to causing thousands of fish to die in a pollution incident.
Dŵr Cymru Welsh Water (DCWW) said it was responsible for breaching environmental legislation which led to the largest fish kill recorded in north Wales when in 2018, it illegally discharged crude settle sewage from a wastewater treatment plant along the River Clywedog in Wrexham.
It affected 9km of river and more than 3,000 fish were killed affecting species including brown trout, bullhead, lamprey, stoneloach, salmon, parr, chub, eel, stickleback, perch and minnow.
The company pleaded guilty to the charges at Llandudno Magistrates Court where it was fined £180,000.
It said the incident occurred during emergency works to clean out a chamber where a colony of snails had formed. In a statement, the company apologised and said it "fell short" of protecting the environment.
"The incident... led to partially treated wastewater overflowing from one of our storage tanks for about one hour into the River Clywedog. Unfortunately, we were unaware this had occurred while undertaking the work, however as soon as we realised we took immediate steps to try and minimise its impact.
'We recognise the short term impact that the incident had on the river which is reflected in our entering a guilty plea at the earliest opportunity.
"We welcome that it was acknowledged that we are a responsible company and were fully open and transparent during the course of investigations and would like to assure our customers that we have introduced robust processes at the works to minimise the risk of the same thing happening in future."
David Powell from Natural Resources Wales said taking legal action against DWCC was the "only course of action".
"I hope this fine will send out a clear message that environmental legislation is to be taken seriously and that damaging the environment, whether deliberately, or out of negligence, comes with consequences.
“Pollution incidents like this can devastate ecosystems... and Natural Resources Wales will not tolerate those who pollute Wales’ rivers, damaging the environment and risking harm to the local wildlife.
He added that they have worked "closely" with Dŵr Cymru Welsh Water to restore the river following the incident.
Dŵr Cymru Welsh Water was also ordered to cover £25,871.60 in related costs, totalling £205,871.50.