We are committed to being a good neighbour, keeping odour and mosquitoes to an absolute minimum.

Odour

In summer 2008, we completed an odour improvement project which involved covering the most smelly parts of the treatment process, and installing equipment to extract and treat air from inside the covered areas.

In September 2008, independent odour experts OdourNet UK Ltd carried out an odour survey to verify whether we had met the required reduction of odour. Their findings showed that odour levels had reduced by 66.2 per cent compared to the 2005 survey.

We carry out regular site odour inspections throughout the day and night, using five odour monitors located in the middle and around the edge of the works.

The monitors measure for levels of hydrogen sulphide, which is one of the compounds that make up odour at sewage treatment works.

Additional odour surveys are regularly undertaken at Mogden, both by Thames Water and the London Borough of Hounslow.

These surveys use a technique called olfactometry, where samples of air are taken at different locations around the works and studied in a laboratory.

Mosquitoes

We follow a strict programme of inspections and treatment to control mosquitoes at Mogden.

The processes we use are audited by local environmental health officers, and based on recommendations from leading independent experts.

We also work with the London boroughs of Hounslow and Richmond upon Thames to raise public awareness of mosquito breeding sites in the wider local area and how to eradicate them.