Another big problem all across the UK is misconnections. A misconnection usually occurs when a home or building is newly constructed or extended and the pipes are plumbed incorrectly into surface water drains (which lead to rivers) instead of foul sewer pipes (which lead to water treatment works), resulting in the waste water from showers, baths, washing machines, toilets, etc. flushing directly into local streams and rivers.
Similarly, a misconnection of a surface water drain to the foul water drain can result in the sewer being overloaded at times of heavy rain. The extra water adds pressure on the water treatment works and sometimes the only course of action is to release the sewage untreated into rivers.
It has been estimated by Defra that between 0.6% and 2.0% of households in the UK – or 150,000 to 500,000 households – may have some sort of misconnection. The most commonly misconnected appliances are washing machines (35%), sinks (20%) and dishwashers (10%), but 5% of instances involve a toilet being misconnected.
If you would like to know how to check your home for misconnections click here