15 April 2016
Results from tests on a range of boreholes across Jersey have shown that ground water supplies tested continue to be within the World Health Organization-based standard limits.
Extra tests are being carried out on surface and ground water sources following the detection of higher than expected levels of pesticides in ground and surface water in February and March. These were Oxadixyl, withdrawn in 2003, and Metribuzin and Linuron (currently used by the farming industry).
The Environment Department has taken 76 borehole samples across Jersey since 14 March and sent them to a UK laboratory for testing. 66 results have come back and at least 20 more samples are likely to be carried out.
Jersey Water is sampling for pesticides weekly rather than every six weeks. Levels of Oxadixyl have largely remained stable across the Island but have increased in Val de la Mare due to less dilution caused by lower rainfall. Linuron continues to be found in a number of surface water streams. Recent tests have also detected other chemicals routinely used by growers; these were Azoxystrobin, Ethoprophos and one incidence of Tebuconazole.
Two other chemicals were also detected. Carbendazim is normally used for amenity grass, and Diuron, a weedkiller, may have been due to an individual householder at the north end of St Peter’s Valley spraying weeds with an out-of-date product on their drive/tennis court or other hard standing.
Val de la Mare reservoir is still not currently being used by Jersey Water. The company is selecting and blending water resources to manage the concentration in the mains water supply and keep it within drinking water limits, which means public mains water supplies remain clean and safe.
The Environment Minister, Deputy Steve Luce, said the new figures showed some cause for cautious optimism. “I’m pleased to see that ground water tests are continuing to show that boreholes are within the precautionary health limit. “Recent meetings with farmers indicate they’re taking their responsibilities seriously and we’re continuing to meet to ensure this remains the case. We’ll also be continuing to raise public awareness more widely about the impact on our environment of using chemicals carelessly.
“I’d like to encourage people to hand in any chemicals used in private gardens that they think may be out of date or banned – without fear of prosecution – to reduce the risk of polluting local water supplies because this is clearly a wider problem and we need to get on top of it.
“As we can see from the example of Diuron, it only takes one person irresponsibly using a chemical to have a marked effect. In this case, the reservoir at La Hague has had to be diverted for a period.”