The report, published yesterday, was commissioned by Environment Minister John Young in February following the discovery of PFOS (a pollutant once used in fire-fighting foam) in borehole drinking water.
The technical officers conducting the report, which also tested for other water pollutants, found that, while levels of PFOS were within global norms and ‘not of concern’, nitrate levels in more than half the Island’s private borehole supplies were above recommended drinking water levels.
‘Testing for nitrates confirms previous findings that approximately half of households supplied by private water systems have supplies with water exceeding the EU and local drinking water limit of 50mg/l3,’ the report stated.
‘Several of the private water supplies tested contained traces of pesticides and other chemicals. Some were over the prescribed legal limit of 0.1ug/l (a precautionary level based on the limit of detection).’
The States’ group director for regulation, Andy Scate, said that ‘nobody really knows’ what is in private water supplies, and those who use them need to ‘really need to understand what is in it’.
‘People with private water supplies need to understand what they have got and what they are using it for – if they are drinking it, they need to really understand what is in it,’ he said.
‘Please be informed if you have a private supply. We do not regulate for private supplies and we do not legislate for private supplies currently. It is down to the private owner, and there is a legal duty if they are giving that water to tenants.’
Commenting on the health risks associated with nitrates, he added that the only way to be sure would be to switch to a mains supply, where no problems with any pollutants had been identified.
‘There is an inherent risk with private supplies, as nobody really knows what is in their water, so the best solution is to get connected to the mains supply,’ he said. ‘We really do need to look at a mains roll-out for as many properties as we can. We are working with Jersey Water to try to get a picture of what that really looks like.’
‘We are going to do a lot more work, as this is an ongoing conversation about water quality,’ he added. ‘We still need to do a lot more research and study to understand what is happening with our water, so that it informs our future water supply debate, because Jersey Water still need to access a lot of raw water for public supplies.’
He added that Jersey Water could fund a mains roll-out through their own company structure.
‘Whether or not they ask government for any money is an interesting debate for the future. But we do not know yet what the financial implications of the mains roll-out would be.’
The States’ medical officer of health, Dr Susan Turnbull, added that, in ‘quite a few’ cases, levels of nitrate pollution had been found to be ‘unacceptably high’.
‘An interesting side effect from this study was that we took the opportunity to also test for other chemicals like nitrates, so we could also get an Island-wide picture of that,’ she said.
‘We are discovering that quite a few boreholes have got unacceptably high levels of nitrate pollution, and there is much more literature about the definitive health impacts from nitrates [as opposed to those related to PFOS].’
