Drinking water – 1994

The UK fifth annual report of the Drinking Water Inspectorate (DWI) shows 99.3% of the 3.5 million tests met national and European Union (EU) standards for all parameters, compared with 98.9% in 1993.
    However, 4.7% of samples exceeded the EU total pesticide residue standard, and 1.2% of samples exceeded the EU limit for individual pesticides.
    Overall, 31 pesticides were detected at concentrations above 0.1 µg/litre (parts per billion) EU standards. Most of these exposures were within the ranges considered acceptable by the less stringent World Health Organisation (WHO), UK or US authorities. The one exception was trichloroacetic acid (TCA) which was detected at concentrations up to 150 µg/l, exceeding WHO standards.
    Pesticides most regularly detected are the herbicides atrazine, diuron, isoproturon, mecoprop and simazine. Some areas are affected more than others: in Yorkshire 19.2% determinations for isoproturon exceeded standards. Recent concerns over isoproturon levels in drinking water have led the UK government to restrict its use (see this page).

Drinking water 1994, DWI, Department of the Environment and Welsh Office, London, £30, 226pp.