Water Quality

Environment - Water quality

Water quality

The sea has been used as a natural sewage treatment system for thousands of years and Langstone Harbour is no exception. The sewage works at Budd's Farm in the north of the harbour originally discharged treated sewage effluent from Havant and the surrounding area into the top of the harbour. This came to an end however when a £120,000,000 engineering scheme by Southern Water was brought into operation. All sewage from Portsmouth and Havant is now pumped to Budd's Farm where it is treated to a high level and sludge removed. It then flows through a newly constructed pipeline under the harbour to the long sea outfall offshore. Sewage now only enters the harbour if, during heavy rainfall, the storm storage tanks cannot cope with the volume of water, in which case the short sea outfalls at Eastney and Budd's Farm may be used.

Responsibility for monitoring harbour waters and consenting discharges into the harbour rests with the Environment Agency and also tested by Portsmouth City Council and Havant Borough Council. While it is recognised that harbour waters are not designated as bathing waters and are unlikely to receive this designation, the level of exposure to harbour water experienced by some users closely matches that of bathers.

Discharge warnings

Water in the harbour in recent years has either been excellent or good when measured against the standards for Bathing Water Quality however this can drop to poor during periods of heavy storm water or high groundwater. The waste water treatment works (WWTW) may not be able to cope with the volume of water entering the system and in these cases diluted sewage which has only received primary treatment (removal of unsightly solids) may be discharged into the harbour. In these circumstances and depending on the volumes released and other factors, water quality may be reduced for the duration of the discharge and for about the next two to four days. Water quality, measured against the Bathing Water Directive, may be poor for this period particularly in the vicinity of the discharge point. When water quality is poor, the advice from the Environmental Health Authority, is: Full immersion is not recommended and all cuts, open wounds and abrasions should be covered with a waterproof dressing. Normal hygiene measures are encouraged where physical exposure to water occurs. (eg wash hands before eating).

The telemetry at the WWTW records actual storm water discharges (SWD) - it is not an ‘early warning alert’. The notifications are added to the website when the Harbour Board receives them from Southern Water. To receive the notifications by email please send us your details using the link below. Langstone Harbour Board gives this advice in the context that water quality in the harbour is now better than it has been for many years and there have been no recorded incidents of fatalities in the harbour caused by poor water quality and there is currently no medical evidence linking water quality in the harbour to illness.