23/05/10
Despite alarmist newspaper articles about combined sewer overflows (CSOs), Britain's beaches have improved significantly in recent years.
Combined sewer overflows are essential elements of legacy wastewater drainage systems routinely installed for much of the last century. The systems combine foul (sewage) flows with surface water. In some places, if there is very heavy rain, drains can be overwhelmed and there is a risk of streets, gardens and even homes being flooded with the combined flow.
Combined sewer overflows are a design necessity in such systems. They are emergency 'release valves' used to prevent sewer flooding and 'backing up' into houses.
Investing in improvement
Major capital expenditure by water and sewerage companies in recent years has brought significant improvement to the quality of Britain's marine and freshwater environments. This is acknowledged by government, environmental regulators, special interest groups and newspapers.
Since 1990 the companies have invested some £85 billion in raising standards, over half in wastewater treatment and environmental improvement. By the end of 2008 more than 6000 overflows posing the highest risk had been improved, rebuilt or removed althogether.
The improvement is seen in the dramatic rise in bathing waters meeting required standards. In 1990 76% of designated bathing waters met the mandatory standard and 29% met the higher guideline standard. In 2009 the equivalent figures were 98% and 80%.
The water industry is not complacent, however.
Companies are working with the Environment Agency and a wide range of other bodies to continue the improvement. Between 2010 and 2015 over £1 billion will be spent on improving CSOs alone. (Total investment by water companies in the period will be £22 billion.)
'Diffuse' pollution
Also acknowledged by government, environmental regulators, special interest groups and newspapers is that currently a far bigger cause of pollution in streams, rivers and bathing waters is non-sewage-related 'diffuse' pollution.
Diffuse pollution comes from a wide range of sources including farming (pesticides and livestock) and urban drainage including road run-off, gully cleaning, industry and misconnections of wastewater to surface water drains.
For full background on CSOs download the Water UK Briefing
For more information please contact:
Water UK Communication
020 7344 1809 (out of hours 07833 450544
