Management of gully pots for optimum runoff quality

Gully pots act as runoff points to surface water sewers, combined sewers and highway drains. Their main purpose is to intercept solid material that would otherwise cause blockages in the sewerage system. They also act as water seals to prevent the escape of odour from combined sewers. However, gully pots can have a detrimental effect on water quality because they provide a reservoir of contaminated sediment and a source of polluted liquor, which can be flushed into sewers and watercourses during routine maintenance or intense summer storms. This book recommends good management practice to minimise these detrimental effects. Following a review of potential problems, the legal position and water quality issues, it sets out guidance for those responsible for installing and maintaining gully pots. The guide concludes that improved designs of gully that retain more sediment would offer significant benefits in reducing pollutant discharge.