Lord Berkeley – 2014 Parliamentary Question to the Department for Environment, Food and Rural Affairs

The below Parliamentary question was asked by Lord Berkeley on 2014-05-07.

To ask Her Majesty’s Government for how many spills a year the Environment Agency has licensed the upgraded Mogden sewage works; and how many were achieved in the first year of operation.

Lord De Mauley

Mogden Sewage Treatment Works has an Environmental Permit issued by the Environment Agency to discharge treated and storm effluent to the Thames Estuary at Isleworth. The discharge of storm effluent is permissible only when the capacity of onsite facilities for treatment and containment are exceeded. This includes a 77,000m³ storm tank.

The permit does not specify a number of spills per year. It requires the works to provide secondary treatment for a specific flow rate of incoming sewage.

The current version of the permit came into effect on 31 March 2013. During the subsequent 12 months, Thames Water reported 54 occasions when the works discharged storm sewage to the Thames. Thirty-four of these were during the wet weather in January and February.