Taylor Wimpey was fined at Cwmbran Magistrates Court on Wednesday for failing to implement appropriate measures to prevent multiple pollution incidents which impacted the river Lwyd and its tributaries.
The Lwyd is 13 miles long and rises at Blaenavon, flows through Pontypool and ends where it meets the river Usk at Caerleon.
According to a statement issued by Natural Resources Wales (NRW), which brought the prosecution, the company was found to have breached the Environmental Permitting Regulations and must pay £488,772 in total, which includes the fine, a £181 victim surcharge and £8591.40 in costs.
The illegal spills took place at the Edlogan Wharf site, in Pontypool, between January and October 2021.
NRW officers discovered that the pollution on each occasion was caused by water run-off from the site, which had been contaminated with silt, and sent warning letters on 23 February and 13 May 2021.
Silty water from construction sites may also contain chemicals such as fuel and oil from machinery or generators, according to NRW, which can be harmful to the surrounding environment.
However, at least six further incidents took place after the warnings with five further alleged incidents.
During a follow up visit in October 2021, NRW officers took and analysed water samples which revealed a significant increase in the levels of small solid particles in the river, which can have a negative impact on fish and other invertebrates by blocking their gills and reducing the amount of light reaching them in the water.
Susan Lenthall, environment officer for NRW, said: “In this case, Taylor Wimpey were made fully aware by NRW officers of the requirements that were needed to install effective silt mitigation methods, that permits were required for discharging treated surface water to a watercourse and that any discharge of contaminated water was an offence under Environmental Permitting Regulations.
“The construction industry has a duty of care to the communities in which they operate, to ensure the correct controls and safeguards are in place in order to prevent incidents such as these occurring.
“I hope this fine will send out a clear message that environmental legislation is to be taken seriously.
“We will not hesitate to take appropriate action against those who disregard regulations and jeopardise the natural environment we all know and love.”
A spokesperson for Taylor Wimpey commented: “Taylor Wimpey has an unwavering commitment to sustainability with a clear strategy to protect and enhance the environment to create a positive contribution to the communities in which we work.
“We accept the outcome and are pleased the judge recognised that Taylor Wimpey takes it responsibilities seriously including our full cooperation with Natural Resources Wales as well as our proactive attempts to manage this isolated issue.”
“Despite our diligent efforts to prevent and remedy surface water issues, including proactive steps based on specialist advice from environmental experts, Taylor Wimpey recognises that these efforts were not sufficient to mitigate the impact of heavy rainfall and adverse weather conditions impacting the site.
"Whilst there is no evidence of actual harm having been caused, Taylor Wimpey expresses genuine regret for the potential environmental problems this issue could have caused.”
Read more about green fines given out in the UK at our Fines Monitor.