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Title: Monitoring the effects of a combined sewer overflow discharge to a small watercourse in South Wales
Author: S.C. Bird
Author: N. Reynolds
Author: R. Henderson
Document Type: Monograph
This report summarises the results of a three year study examining the chemical and biological impacts of a combined sever overflow on its receiving water in South Vales. The high side weir overflow serves a population of around 3,000 and is characterised only by domestic inputs. It discharges into a small highly reaerated stream of NVC Class 2 quality. The study began in 1987 under the control of the Velsh Water Authority, but was completed under the auspices of the National Rivers Authority (Welsh Region) research and development programme. In all 25 spill events were monitored and their impact assessed. The chemical quality o^the overflow spill was highly variable with BOD levels averaging 77mg/l, ammonia 3.7mg and suspended solids 462 mg/l. Broadly, spill quality appeared to reflect crude flow quality, with the most contaminated events occurring in the late afternoon and early evening. The presence of a first foul flush was observed in 362 of all cases. Most of those also exhibited a secondary flush at times of pejk spill flow rates, generally spill rates varied between 30 and 60 is -1 , not exceeding 420 ls-1.
Publisher: National Rivers Authority
Publication Date: 1990
Publication Place: Cardiff
Subject Keywords: RiversWater pollutionSewageEffluentsPollution monitoringChemical contaminationBiological surveys
Geographic Keywords: Wales
Extent: n.p. [354]
Total file downloads: 271

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