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Title: Investigation into potential exfiltration of raw sewage from Salcombe sewer
Author: S. Hunter
Document Type: Monograph
Annotation: EA additional title info: Devon Area internal report March 2000
Salcombe main sewer runs along the foreshore of Salcombe town centre. The section of sewer to be investigated begins at Shadycombe Pumping Station and runs in the intertidal zone to a ROTORK valve situated at Sunnycliff Bay. At Sunnycliff the sewer turns inland and runs up to Malborough Waste Water Treatment Works. Wastewater from Shadycombe Pumping Station is pumped up to Malborough Waste Water Treatment Works (WWTW) via Salcombe foreshore. There have been problems at Malborough works caused by the infiltration of saltwater into the sewer pipe at Salcombe. In an effort to rectify this problem a ROTORK valve was installed at Sunnycliff Bay (the end section of the pipe on Salcombe foreshore). Also, a saline retention tank has been installed at Malborough WWTW. An investigation into the frequency of overflow from the saline retention tank has been carried out by Robin Pearson (Environment Protection Investigations Officer). The ROTORK valve operates by opening and closing to varying degrees in an effort to equilibrate the pressure of the sewage in the pipe with the rising and falling tide. The concern is that if the pipe is over pressurised raw sewage could be forced out of the same defects in the pipe that allowed the infiltration of saltwater initially. The aim of this investigation is to locate any exfiltration from the main sewer running along Salcombe foreshore. This will be achieved by dosing the length of sewer from a manhole located in Shadycombe carpark, to the ROTORK valve at Sunnycliff bay (with the biological tracer Bacilus globigii) then, sampling the body of water above the main sewer during high tide.
Publisher: Environment Agency
Publication Date: 2000
Publication Place: Exeter
Subject Keywords: RiversWater pollutionSewage treatmentSewageWastewaterWater quality surveysBacteriaBacterial counting
Geographic Keywords: Salcombe (Devon)
Extent: 14
Total file downloads: 276

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