Saturday, 31 August 2013

Why we should worry about water quality

The Drinking Water Quality Regulator for Scotland has published the annual report on the quality of drinking water in Scotland. It highlights some public health concerns across Scotland.

Media reports have expressed some surprise that the overall quality of water in Scotland is worse than in England. I remember when Sam Galbraith was the water minister, he was so shocked at this that he carried around slides with charts that illustrated this point. When Sam was the minister this was an issue, but less so today. Scottish Water has improved compliance rates in the last ten years so that 99.86% of samples are now compliant. Last year also saw a 31% decrease in customer contacts about water quality. We should also remember that Scotland's geography, pipes and storage units create special challenges for Scottish Water. Further progress will depend on completing the massive capital programme that has delivered water quality improvement in Scotland far more cost effectively than the privatised utilities in England.

DWQR is of the opinion that the pace of improvement in microbiological compliance at storage points is too slow and more rigorous investigation of failures needs to take place. Trihalomethane compliance (by product of disinfection process) at the taps was similar to 2011 and is still too high. A warning that Scottish Water cannot rest on its laurels or put cost cutting ahead of compliance. Scottish Water also needs to recognise that two of the major incidents involved contractors that they have less control over. Outsourcing has its downside.

Private water supplies (PWS) are drinking water supplies which are not the responsibility of Scottish Water but of their owners and users. Enforcement is the responsibility of local authorities and the regulator is concerned over the reduction in inspections. Only two councils met the required standard. As UNISON has highlighted, this is due to council staff cuts and, as in food and other safety inspections, public health is being put at risk.

The quality of all PWS, continues to be of concern to the regulator. Of 2,158 tests on Type A supplies for E. coli, which is used as an indicator for faecal contamination, 333 (15%) contained E. coli and therefore failed the standard, a similar proportion to 2011. As a comparison, less than 0.01% of public water supplies failed the standard. Coliform bacteria were found in a third of private supplies. Failures are even happening in supplies where there is disinfection.

One type of contamination that most people think has gone is lead. Scottish Water has removed lead pipes from the distribution mains, but it has not been removed completely from the system.  Scottish Water does not hold detailed records of all their communication pipes, but as a result of an FoI request by Utilities Scotland they estimate 72,000 of the 1.8 million communication pipes in Scotland are lead. Scottish Water is not the owner and therefore not responsible for the privately owned supply pipes to properties and nobody appears to know exactly how many of these are still lead. However, it has been estimated that 40% of UK homes still have lead supply pipes.

Although the majority of lead piping is privately owned and therefore outside Scottish Water’s direct control, the company does have a responsibility under the Regulations to minimise the extent to which the water supplied dissolves lead. The standard for lead will reduce from 25μg/l to 10μg/l at the end of 2013, and the regulator states that Scottish Water needs to continue to implement measures to reduce the amount of lead in water supplies and produce a documented strategy for doing so. The eight failures last year would rise to 31 under the new standard. We should remember these are only sample failures. The actual levels of contamination will be many multiples of these samples.

Recent medical opinion suggests that lead concentrations should be as low as possible, hence the improving standard. Actually, there is no safe level of lead contamination and this is an issue we should be addressing. In February this year Utilities Scotland highlighted the debate starting in England over this issue, including moving control of supply pipes to water companies. We should be having the same debate in Scotland as well.

Water quality is a subject that doesn't get much attention in Scotland. There are commercial sensitivities given the association of high quality water with mineral water and whisky industries. However, this should not stop a debate around issues like private water supplies, inspection levels and lead contamination. Public health must come first. 


Cross posted from Utilites Scotland.








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