Purpose

The job of policing the nations rivers and watercourses rests with the Environment Agency.  The Agency regulates, controls and monitors all known point discharges.  However, pollution entering these waters by means of diffuse, irregular or intermittent sources is much more difficult to identify.  This diffuse pollution in urban areas is very likely to be of sewerage origin.  Wessex Water is responsible for all of the foul and surface water public sewers in the Wessex Region and has recognised its responsibility towards pollution prevention by setting up Operation Streamclean.  The purpose of Operation Streamclean is to investigate, identify and reduce the incidences of pollution of surface waters by sewage.

Organisation

The first Streamclean venture was set up in Bristol in 1992 where it was responsible for major reductions in the frequency and volumes of sewage polluting several local streams.  The present operation now covers the whole of the Wessex region.  There are two teams of two operators, each fully equipped (including CCTV equipment) to investigate sewers, chambers, manholes, pumping stations and streams etc.   They are supervised by a lead operator based in Poole and are managed by the Sewerage Manager.  They have a functional link to scientists who can direct and interpret their investigations. This organisational flexibility allows them to call upon experienced local engineers, sewerage teams and scientists as the need arises.

Methods

The Streamclean teams work closely with the Environment Agency and Environmental Health Officers in arriving at priority areas for investigation.  

The teams use local knowledge, GIS mapping, surveys, sampling and analysis and in-sewer monitoring techniques to pinpoint the cause of a pollution.  

Once identified, enforcement of remedial measures is organised by the Streamclean manager.  

Responsibility for enforcement could lie with the Environment Agency (who have certain powers to prevent pollution), with Environmental Health under the Building Regulations or with other statutory agencies like Highways departments.  

In some circumstances, where there is no clear responsibility, Wessex Water has directly organised the remedial work.

What does Operation Streamclean look for?

Most homes built in the past 30 years have ‘separate’ drains, with two drainage systems:

1. the foul sewer, carries dirty water to a sewage treatment works where it is treated before it is discharged to a river;

2. the surface water drain, carries clean water directly to a river or soak-away, as do most road drains.

Wrong connections occur when toilets, washing machines, dishwashers, baths, and showers are connected by mistake to the surface water drain.  This often happens when an extension is built, or when a new appliance is installed and sometimes when a new house is built and the builder connects to the wrong drain.  Any discharge to the surface water drain will pass untreated into a stream or soak-away and will cause pollution.  In a stream, this will cause unpleasant smells and unhealthy conditions where plants and fish will not survive.  If the pollution enters a bathing water (e.g. via the Bourne Stream) it can affect a blue flag area and make bathing or paddling unsafe.

The Operation Streamclean teams are particularly looking for wrong connections.