The report reveals that the number of reported and substantiated incidents fell by 10% and 14%, respectively, from 1995 levels (see table ). The number of serious "category 1" incidents also declined for the fourth year in succession.
The 60% decline in serious incidents over the last five years is a notable achievement for the Agency and its predecessor, the National Rivers Authority. However, the report cautions that the encouraging figures in part reflect a very dry year. Lack of rainfall reduces the frequency of pollution from silage, animal waste and storm sewage overflows.
The water and sewerage industry was the largest source of pollution, accounting for 28% of incidents - 2% less than in 1995. Other industries accounted for 20% of pollution incidents, followed by agriculture (10%), transport (9%) and domestic properties (6%).
Industry was the biggest source of serious incidents (26%), followed by the water and sewerage industry (20%) and agriculture (18%). Some 28% of serious incidents came from other sources, including fish kills caused by reduced oxygen levels resulting from "natural" low flows. The report notes that these are becoming more common (see pp 8-10 ).
Construction was the industry sector which caused most pollution - with over 500 incidents. The food industry came second, with engineering, chemicals and mining each causing 300-400 incidents. Textiles, filling stations, and the waste and paper industries were each responsible for about 100 incidents.
The report draws particular attention to oil pollution, which accounted for 28% of incidents - more than any other type of pollutant. Proposals for new regulations setting minimum pollution prevention standards for oil stores were put out for consultation last December (ENDS Report 263, pp 31-32 ).
The Agency has brought prosecutions for 139 incidents which occurred in 1996, but in January 1997 a further 91 had still to be heard. By the end of 1996, 28 cases had been brought for "category 1" incidents - 18% of the 156 incidents which occurred during the year, and a marked increase on the 8% figure reported for 1995.
The largest fine for a pollution offence was £175,000, imposed on Severn Trent Water after a chemical leak killed thousands of fish in a Welsh river (ENDS Report 259, p 38 ). Over and above fines and legal costs, the Agency recovered clean-up costs from polluters totalling £1.37 million. The largest sum was £141,428 for a spillage of nitrobenzene from a road tanker accident on Teesside (ENDS Report 254, p 12 ).