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Title: National Rivers Authority river quality survey GQA assessment 1993 Nothumbria and Yorkshire Region. Part 1 Reach classification : Freshwater rivers and canals
Author: National Rivers Authority Northumbria and Yorkshire Region
Document Type: Monograph
The basic chemical grade of the GQA Scheme is defined by standards for the concentrations of BOD, ammonia and dssolved oxygen. These have been selected because they are indicators of the extent to which waters are affected by wastewater discharges and rural land use run-off containing organic, degradable material. The quality of many of our rivers and canals is affected by such discharges which include effluents from sewage treatment works and industries, and drainage from farms. These three simple determinands are therefore the best overall basic chemical measure of river water quality for the purpose of GQA which will apply to all rivers and canals within the classified network. The use of these three determinands provides some continuity with the NWC system. In the GQA assessment, however, data from three years sampling is used to make the assessment of class. For the 1993 assessment, data from 1991,1992 and 1993 has been used.
Publisher: National Rivers Authority
Publication Date: 1994
Publication Place: Newcastle Upon Tyne
Subject Keywords: Pollutant loadRiversCanalsEffluentsSewage treatmentPollution monitoring
Geographic Keywords: EA Yorkshire and North East
Extent: n.p. [209]
Total file downloads: 313

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