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Title: The quality of rivers, canals and estuaries in England and Wales : report of the 1990 survey
Author: National Rivers Authority
Document Type: Monograph
A major survey was carried out during 1990 by the National Rivers Authority to assess the quality of rivers, canals and estuaries in England and Wales. The previous survey of similar extent, in 1985, was coordinated by the Department of the Environment, Welsh Office and by the regional Water Authorities. Using the classification systems introduced by the National Water Council, the 1990 Survey found that about 89 per cent of rivers, 90 per cent of canals, and 90 per cent of estuaries were of either Good or Fair quality, about 2 per cent, 1 per cent and 3 per cent respectively were of Bad quality. A large number of changes in quality class of individual stretches of water were recorded compared with 1985. About 15 per cent of the total river length was downgraded, about 11 per cent upgraded. Comparable changes for canals were 15 per cent and 7 per cent, and for estuaries, 3 per cent and 1 per cent. For rivers, canals and estuaries, most of the decline was in the best quality waters. The net overall downgrading is mostly explained by three factors. First, changes in methodology, particularly the increased monitoring effort in some Regions. This provided more accurate information on water quality than was available in 1985. The two other factors are the effect of two hot, dry summers and discharges from sewage works, industry and farms. It is estimated that these three factors contributed in approximately equal proportions to the net assessment of deterioration in water quality. Where water quality improved this was either because of better treatment of waste waters, or because industries closed down. Increased enforcement by the NRA may also have begun to have an impact on the efforts of dischargers to make sure that they comply with consents.
Publisher: National Rivers Authority
Publication Date: 1991
Publication Place: Bristol
Subject Keywords: Water qualityCanalsRiversEstuariesWater quality surveysPollution
Geographic Keywords: EnglandWales
Extent: 63
Total file downloads: 258

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