Scottish drinking water improves

Between 1998 and 1999 there was a 13% fall in the number of drinking water samples failing tests, with a 38% drop in the number of samples failing to meet strict microbiological standards, and a 31% reduction in samples containing disinfectant by-products, says the report.

“These results demonstrate continued improvement in the performance of the three Scottish water authorities,” said Galbraith. “This improvement is a direct result of the Scottish Executive’s commitment, outlined in the Programme for Government, to invest to deliver higher drinking water standards for the people of Scotland.”

Despite these improvements, however, there is still work to be done, said the Minister. In particular, continued investment by Scotland’s water authorities is being directed towards solving the problem of contamination through by-products of the disinfection process, the trihalomethanes (THM). These chemicals occur in drinking water as a result of the reaction between chlorine and naturally occurring organic materials, a problem which the World Health Organisation drew attention to, saying that disinfection should never be compromised. The majority of the THM failures occurred in small rural supplies with only simple treatment prior to chlorination, and, according to the Executive, a new treatment works being developed for the Loch Lomond supply should cut out a number of these failures.

“The water authorities accept that having taken measures to improve the disinfection of water supplies further investment is needed to meet the standards the Scottish Executive expects,” said Galbraith. “Further investment by the water authorities such as the new treatment works at Balmore (£46 million from East of Scotland Water) and Blairlinnans (£17.5 million from West of Scotland Water) should ensure continued improvements.”

The drinking water quality results for 1999 have been derived from over 143,000 tests on samples of water taken from customers’ taps, with 2,068 failures to meet the relevant standard, compared to 2,994 such failures in 1998. There was a 54% decrease in failures of the coliform standard, and a 56% decrease in faecal coliform failures.

Scotland’s three water authorities are still publicly owned, a Scottish Executive spokesperson explained to edie, and are: East of Scotland Water, West of Scotland Water, and North of Scotland Water.

Copies of Drinking Water Quality in Scotland 1999 (ISBN 1 84268 088 9) are available from the Stationary Office Bookshop, 71 Lothian Road, Edinburgh, EH3 9AZ.