WORMTECH, the waste management and recycling company has been fined more than £40,000 after polluting a brook – forcing Caerwent's Ministry of Defence training base into quarantine for three months.

 The company appeared at Newport Magistrates Court last week over the pollution of the Nedern Brook, in Caldicot.

Wormtech Limited is based at the Centurion Business Park and the company's environmental director Jacqueline Powell pleaded guilty on behalf of the company to two charges of polluting the Nedern Brook between January 1 and April 6 in 2010 and failing to comply with an enforcement notice served on the company in August that year by the deadline of October 26. Two additional charges were withdrawn at the hearing. 

The court was told that officers from Environment Agency Wales' Usk Environment management team had been working with Monmouthshire County Council's environmental health department and Welsh Water to identify the causes of the problems in the brook after receiving increasing numbers of reports from the army and local people over the discolouration in the water and odours.

The Caerwent site has five areas Sites of Special Scientific Interest and wildlife in this area include great crested newts, bats, dormice, badgers and an array of wild flowers.

Welsh Water and Monmouthshire County Council carried out dye tracing to try and locate the problem on the brook, which discharges into a field drain on the Caldicot Levels and into Caldicot Pill.

But when the pollution was tested it was found to contain traces of Ecoli and as soldiers use the Caerwent MoD site's ditches and streams as part of their training it was deemed a risk to human health, forcing management to quarantine the area for three months.

The Environment Agency's prosecuting solicitor Mohammed Yakub said the company composts some 25,000 tonnes a year of green and food waste. He explained to the court that the composting process creates a leachate that must be contained in a holding tank.

Mr Yakub likened the waste liquor to farmers' slurry and said: "The liquor seeped out, polluting ditches, streams and brooks. The army had to quarantine an area, leaving personnel unable to train in an area where they would have jumped in ditches and streams."

He added that the infected area of the site was closed between March and June because of the risk to human health.

The court was told that on inspection the Environment Agency found that 23,100 milligrammes of pollution was found in the leachate in the infected area. Mr Yakub explained that the levels for a healthy stream were between 0 and nine milligrammes.

Wormtech was granted planning permission in February 2004 for a composting facility and the whole operation is carried out inside converted military buildings which are classed as an in-vessel operation, meaning that the buildings themselves are the in-vessels, as they can be sealed from the environment.

Mr Yakub said: "This is the strongest case of its type I have come across. The levels of contamination are unprecedented affecting the biodiversity of the area, polluting streams around the MoD area and the Nedern Brook, which is two kilometres away from the recycling plant."

Martin Jones, defending solicitor said in mitigation said that the enforcement notice which had been served on the company had now been complied with, but admitted this had not been achieved by the enforcement deadline of last October.

Mr Jones told the court that Wormtech had struggled to get the necessary planning permission in time, but they have now installed a sealed drainage system and that additional safety measures had been introduced with employees keeping a site diary. He added that culverts were being cleaned twice a day.

Chairman of the Magistrates Edwin Martin fined Wormtech £10,000 for polluting the Nedern Brook and an additional £25,000 for failing to comply with the enforcement order. He also ordered that £6,000 costs to the Environment Agency were to be paid along with a £15 victim surcharge.