25/01/10
Misconnections from domestic properties are an important source of urban diffuse pollution in the UK. The Environment Agency, Water UK, a number of the water companies and others are working together in partnership to improve the quality of our rivers and beaches by working to reduce the impact of misconnections.
What are misconnections?
There are normally two forms of drainage from houses:
• In a combined network, foul and surface water drain together into the same sewer. In dry weather all wastewater goes to the sewage treatment works. In wet weather, to prevent flooding properties, overflows operate, which discharge diluted sewage into watercourses; or
• a separate drainage system (or split-system) has two different sewers; one for surface water and one for foul water. Surface water sewers carry rainwater from road surfaces and rooftops into local rivers and streams untreated. Foul water drains carry wastewater to the foul sewer and on to the sewage treatment works. The wastewater is treated before it can be safely returned into rivers and streams.
There are two forms of misconnection:
Incorrect plumbing can mean that wastewater from white goods, showers, baths and toilets is flushed directly into a local river via surface water drains instead of being connected to the foul water drain. These 'misconnected' pipes are a common cause of pollution to rivers and streams, especially in towns and cities.
Around 300,000 homes are affected by misconnections in England and Wales/UK. People doing their own plumbing and sometimes even professional plumbers can create these misconnections.
Where a development is served by separate drainage systems, surface water may be incorrectly connected to the foul sewer, which may cause sewer flooding.
Misconnections are likely to contribute to the risk of some bathing and shellfish waters not meeting their water quality targets. The cumulative impact of misconnections in England and Wales is huge. It is equivalent to a sewage discharge from a town the size of Swindon or a volume of about 16 Olympic-sized swimming pools per day.
What are we doing about misconnections?
This partnership is working with a wide range of stakeholders to address this challenge and running a programme to rectify existing problems and prevent more
misconnections being made.
This includes:
• establishing a strategic partnership group with water companies and others to promote misconnection awareness, educate key stakeholders such as plumbers, builders, housing associations, and building and plumbing merchants
• developing an understanding of the impact of misconnections on the environment
• producing a best practice guide for water companies on how to deal with misconnections
• identifying whether new legislation is needed to rectify the problem
• delivering an awareness campaign to inform the public and other stakeholders about the problem and encourage them to identify and correct misconnections. This includes creating a website, leaflet and running localised campaigns. We want to prevent misconnections occurring in the first place and make sure tradesmen and builders take steps to ensure houses are connected properly.
