Skip to main content


Title: River quality survey NRA Northumbria and Yorkshire region GQA assessment 1995. Part 1 Reach classification. Freshwater rivers and canals
Author: Environment Agency North East Region
Document Type: Monograph
To allow the development of a National method of evaluating water quality, the rivers in all the NRA regions of England and Wales have been divided into reaches, which are numbered using a coding system based on the hydrological reference for each river basin. Each classified reach then has a chemistry sample point and a nearby biology sample point assigned to it. The chemistry sample point is monitored for Biochemical Oxygen Demand (BOD), Dissolved Oxygen (DO) and Total Ammonia. Samples of macro invertebrates (bottom living animals) are taken at the biology sample point. Chemistry grades are reported every year. Three years data (e.g. 1993, 1994 and 1995 data) are combined to calculate the grade for a stretch. It is anticipated that biology grades will only be reported once every five years and that one year's data will be used to assign the grade for a stretch. This report therefore lists results for a national biological monitoring survey carried out in 1995 and the next survey from which results will be reported will take place in the year 2000. Each regions results are sent to a National Centre where the GQA grades for chemistry and biology are calculated. A National report is produced and each region can then produce more detailed reports on the quality of their own rivers. For Northumbria and Yorkshire Region, the regional report has been divided into two parts: "Reach classification" and "sample point report". The first part contains a listing of the river reaches within the region, with their start and finish grid reference, approximate length, and the 1990 and 1995 GQA biology and chemistry classification. The reference codes (SPTs) for the biology and chemistry sample points used to classify the reach are also included. The second part contains more detailed information on the summary statistics for each chemical GQA sample point. The sample points are listed in numeric order and the summary statistics from the 1990 and 1995 classification are provided for comparison.
Publisher: Environment Agency
Publication Date: 1996
Publication Place: Newcastle Upon Tyne
Subject Keywords: RiversCanalsWater qualityWater quality surveysClassificationQuality assurance
Geographic Keywords: EA Yorkshire and North East
Extent: 88
Total file downloads: 401

Download PDF    Display PDF in separate tab