§ Mr. RuaneTo ask the Secretary of State for the Environment, Transport and the Regions (1) how many grossly polluted miles of river there were in each of the past 20 years; [137826]
(2) if he will list the rivers that failed to reach the EC Urban Waste Water Directive in each of the past nine years. [137828]
§ Mr. MullinThe information available on grossly polluted rivers is as follows:
Year River lengths classified 1 grade F (Bad) in England and Wales (miles) 1999 147 1998 186 1997 281 1996 263 1995 232 1994 254 1993 361 1992 424 1991 — 1990 496 19852 404 19802 398 1 The General Quality Assessment (GQA) scheme bases chemical river assessments on three determinants: dissolved oxygen, ammonia and biochemical oxygen demand. Samples are taken at 7,000 sites representing 25,000 miles of rivers and canals. Rivers are classified according to one of 6 grades from "Very Good" (A) to "Bad" (F). 2 Assessments prior to 1990 were based on a slightly different scheme. These were the lengths classified as "Bad" in that scheme. The Urban Waste Water Treatment Directive does not set quality standards for rivers. It sets standards for the quality of treated effluent discharged from sewage treatment works, based on the size of the discharge and the nature of the receiving waters.