2. Executive Summary
This is the fifth annual report prepared by the Drinking Water Quality Regulator for Scotland ( DWQR) and submitted to Scottish Ministers. It presents and reviews the information provided by Scottish Water under the Water Supply (Water Quality) (Scotland) Regulations 2001 ("the 2001 Regulations") and reflects the dealings that the DWQR had with Scottish Water between 1 January and 31 December 2006. The report also presents and reviews information on private supplies provided by the Local Authorities. Section 3 of this report covers drinking water quality at a national level, examining the water quality in sources, at water treatment works, and through the distribution system to consumers' taps. Section 4 breaks the national picture down into the five regions represented by the Waterwatch Scotland panel areas, and provides details of water quality at consumers' taps by local authority area.
The drinking water quality results reported by Scottish Water for 2006 show that 360,959 tests were carried out on samples taken from water treatment works, service reservoirs and consumer taps. Of the 170,552 tests on samples taken from consumer taps, 99.66% complied with requirements for which there is a numerical standard. A total of 577 tests gave results which did not meet the standard set out in the 2001 Regulations. As in previous years, the largest number of failing samples was for the total coliform and trihalomethane parameters.
Compliance with the key microbiological parameters was greatly improved in 2006 compared with 2005. In 2006 there were 114 failures of the coliform standard at consumers' taps and 9 E.coli, comparing favourably with 138 and 21 respectively in 2005. Data going back to the year 1991 are shown in Figure 2.1, and these clearly show how the 2006 microbiology results are the best since the original water quality Regulations were introduced in 1991.
Fig 2.1 Summary of Microbiological Tests on Tap Samples Since 1991
Extensive sampling of raw and final waters for Cryptosporidium was undertaken in 2006 in accordance with the Cryptosporidium (Scottish Water) Directions 2003. Final Water samples were taken from 304 water treatment works, providing 10,602 samples throughout the year. Of these samples, 667 (6.3%) contained Cryptosporidium oocysts.
DWQR threatened enforcement action against Scottish Water for non-trivial breaches of the Regulations at four sites during 2006. Only one of these subsequently resulted in the issue of an enforcement notice, but Scottish Water completed the required work at Balmacara in Highland Council area within the terms of the notice.
DWQR receives details from Scottish Water of events which could affect drinking water quality. In 2006, 54 such events were considered sufficiently serious to be classified as incidents. Where appropriate, DWQR investigated the circumstances of these incidents and made recommendations.
In 2006 Scottish Water was contacted 48,320 times by consumers regarding drinking water quality issues; of these contacts some 25,299 were complaints. The majority (56.9%) of complaints concerned discoloured supplies.