Scottish Power is facing calls this weekend to explain apparent inconsistencies in reports commissioned by the energy giant which provided assurances that Britain’s largest onshore wind farm was not to blame for polluting ground water.
Almost 40 water samples collected from across the 215-turbine Whitelee wind farm between 2006 and 2008 contained traces of a toxic compound at levels of up to 400 times greater than those deemed safe by the World Health Organisation (WHO) in drinking water.
The wind farm is about 10 miles from Glasgow and dozens of homeowners living in its shadow rely on ground water collected in underground tanks for their private supply.
Details of the contamination were highlighted in regular reports to Scottish Power by Jacobs, an engineering firm hired to monitor ground water quality at Whitelee.
In one, dated November 2009, the year Whitelee was officially opened, DEHP – a compound commonly used in plastic products to make them flexible and identified as carcinogenic in animals, and possibly humans – was described as being present at “low levels”. The report concluded that cross-contamination “within the laboratory” was “thought” to be responsible.
In a previous report dated December 2008, Jacobs indicated the laboratory had used robust scientific techniques but had been unable to identify the source of the cross- contamination.
On Friday, those statements appeared to be undermined by an official at Scientific Analysis Laboratories, based in East Kilbride, who told The Sunday Times that such significant levels of DEHP were unlikely to have been caused by contamination on its premises.
Opposition politicians have expressed disbelief that the precise source of such a potentially serious contaminant on a water catchment area was not identified. Graeme Pearson, the Labour MSP, said he intended to raise the matter with Richard Lochhead, the environment minister.
DEHP, also known as bis (2-ethylhexyl) phthalate, is not listed as a hazardous substance by the Scottish Environment Protection Agency but a European Commission dossier published in October 2013 raised concerns about its potential health risks for humans and animals. The International Agency for Research on Cancer has categorised DEHP as “possibly carcinogenic to humans”.
Last week, despite the brewing storm, staff at Jacobs refused to respond to several approaches by this newspaper. A spokesman for Scottish Power said that when concerns were first raised about elevated DEHP levels, additional tests showed the compound was also present in “laboratory blanks”. The energy firm said it was “absolutely confident” that contamination occurred during the sampling process.
However, the presence of DEHP in water samples from Whitelee – and the failure to establish exactly how contamination occurred – will be used in a legal challenge by campaigners against Scottish Power’s plans to build a further five turbines.
They claim construction of the turbines is likely to have a “significant effect on both public and private water supplies” and that environmental submissions by Scottish Power have failed to identify the risks.
Rachel Connor, a member of the Protect Our Water group who first drew public attention to the elevated levels of DEHP in water samples from Whitelee, said: “What I find of particular concern is the very large number of households who will have been relying on this ground water from the Whitelee site, including ourselves, who may have been exposed to these extraordinarily high levels for some years and yet there is no regulatory authority who either seems to know about this, or who is taking responsibility for dealing with this.”
Pearson added: “I’m disappointed that the precise source of contaminated water samples from Whitelee has never been identified. Why has it taken a member of the public to highlight this apparent failing?”
Guidelines laid down by the WHO in 1993 recommend that levels of DEHP in drinking water should not exceed 8 microgrammes per litre (µg/l).
According to the 2009 Jacobs report, this level was exceeded in every one of 38 samples taken at eight boreholes across the Whitelee site between September 2006 and May 2008.
The highest readings – ranging from 67 to 3,200 µg/l – were in samples collected on January 8, 2008. On December 5, 2007, DEHP was detected at levels of between 120 to 1,000 µg/l. On other days, the compound was not detected in any samples.
Wider concerns about the potential impact of wind farm construction on water supplies have prompted Scottish Water to commission an investigation by scientists at the James Hutton Institute.
A spokesman for Scottish Power Renewables said: “There was rigorous testing and monitoring of ground water at Whitelee during construction, which shows that construction activity did not negatively impact ground water. Monitors for the planning authorities, Scottish Water representatives, our independent consultants and project team were issued quarterly reports during construction. Even when monitoring reports identified that lab cross-contamination had created spurious results, we still fully reviewed all of our construction activities to ensure that construction had not caused any issues.”