Many of you have recently contacted me about the Sewage (Inland Waters) Private Members Bill.
Many of our sewer systems are combined systems, where sewage is combined with rainwater. During and after heavy or prolonged rainfall, or if the groundwater table is high, the capacity of combined sewer systems can be exceeded. Storm overflows act as relief valves to discharge excess sewage combined with rainwater to rivers or the sea, protecting properties from flooding and preventing sewage backing up into streets and homes. Storm overflows are a last resort in modern sewer design, but the age of our sewerage systems means their complete elimination is not practicable or affordable. I am assured, however, that Ministers recognise there is more to do on the issue of sewage pollution and are very supportive of the aims of this Bill.
My Ministerial colleague, Rebecca Pow MP, met water company CEOs in September 2020 and made clear that the volume of sewage discharged into rivers and other waterways in extreme weather must be reduced. I am aware that water companies are already committed to a significant programme of improvements to the monitoring and management of storm overflows at a cost of around £1.2 billion, including over 700 schemes to provide environmental improvements by reducing spills from frequently spilling overflows. As part of this investment, ‘Event Duration Monitoring’ is currently being installed on most storm overflows to trigger investigations and improvements by water companies when overflows operate too frequently.
I have listened to your concerns and have recently written to the CEO of Southern Water about sewage discharge from Southern Water sites on the Island. I asked for comment as to how effective the efforts to eliminate the need for discharges have been in Southern Water’s view and, if further work is needed, what assistance Southern Water may require from government so that I may assist where possible and if needed.
Sothern Water replied with the following:
“As previously explained, like all other national water companies, we design, build and maintain our sewage apparatus and systems based on permits by the Environment Agency (EA). During poor weather, particularly during very wet weather, flow coming into the system can exceed a station’s capability to pump and when this happens, stormwater is released into the environment often via a Combined Sewer Overflow (CSO). This operates like a ‘release valve’ when the system becomes surcharged. These stormwater discharges by national water companies from CSOs are permitted by the EA.
"As such, permitted stormwater releases will always be a necessary part of the wastewater system and we and other water companies will continue to use them to protect our customers and communities.
"Stormwater is not ‘raw sewage’, rather it is heavily-diluted wastewater and rainwater run-off from roads and gardens, and it is screened (it passes through a metal screen) and ‘settled’ (solids settle in a large tank and only the fluids are released). These necessary releases occur to prevent local homes and other properties, such as local hospitals and schools, from flooding with wastewater when the system is surcharged. Sewer networks in this country do not operate as a closed system and the permits issued by the EA take into account the dilution factor during a storm, sensitivity and amenity of the receiving watercourse. Failure to meet these permits is a criminal offence.
"All of our wastewater stations have alarms so we can monitor and respond to releases. We are obliged to keep records of, and report these alarms to, the EA. We are proud to be one of the first water companies to publish all of our releases, and other environmental information on our website.
"Recently we have invested more than £3m in a stormwater retention tank at Shanklin and have undertaken multi-million pound upgrades at the East Cowes, Newport, Ryde and Sandown sites.
"Every week between May and October, the EA takes bathing water samples from the Isle of Wight’s 14 designated bathing water beaches. We work closely with the EA and Isle of Wight Council to maintain the Island’s exceptional bathing water standards, which are some of the cleanest in the world. The latest data is here: http://environment.data.gov.uk/bwq/profiles/
"Finally, thank you also for your offer of assistance. You may be aware that the topic of stormwater releases by UK water companies has attracted a lot of media coverage lately and that there is now a Storm Overflows Taskforce comprising representatives of Defra, the Environment Agency, Ofwat, CCW, Water UK and a water company. You may want to liaise with George Eustice’s office about this”.
As well as this, through the Environment Bill, sewerage undertakers will be required to produce a statutory Drainage and Sewerage Management Plan to actively address environmental risks, such as sewer overflows and their impact on water quality. Ministers have also set up a new Taskforce to set out clear proposals to address the volumes of sewage discharged into our rivers.
The Government will respond formally to this Bill during its Second Reading; however I assure you that making progress on this issue is a top priority!