Concerns over quality of Sark’s drinking water

It is being proposed that the Policy & Finance Committee employs a qualified hydrogeologist to investigate the water supply.

There is no reliable data on the quality and quantity of the water supply in Sark.

Attached to the Chief Pleas proposal, which will be discussed on Wednesday 10 April, is a letter from La Societe Sercquaise geology section lead Dr Roger Norwich, explaining the scope of the proposed work.

‘Concerns within the community have been raised about the quantity and quality of the Sark water supply for many years, with disquiet being expressed in a number of reports going back to 1974,’ he said.

‘The most recent report was undertaken by the British Geological Survey in 2004 which made multiple recommendations, which were never acted upon.’

Sark has a water testing regime which is very basic and is largely restricted to annual testing for coliform bacteria at commercial premises such as hotels, restaurants, and tourist accommodation.

Dr Norwich said that most recent test results have shown that there are occurrences of bacterial contamination of the water supply, particularly where borehole water is shared.

‘It is unlikely that these limited test results represent anything other than all may not be well with the Sark water supply,’ he said.

He raised concerns that there was ‘virtually no useful information’ regarding the number and positioning of boreholes and wells, the positioning of septic and effluent tanks and details of the depths of individual boreholes and the variations in their water depths at different times of the year.

‘There is... no data regarding the efficiency or otherwise of the many septic tanks, nor the overall management of effluent tanks and how these may or may not be affecting the quality of water.’

He noted that Sark has metallic mineralisation.

‘While the metals such as copper and silver are locally evident in the area near the old mine, there is no good data concerning any such similar mineralisation in other parts of the island,’ he said.

‘There is some data that some individual residents have paid for of more in depth water analysis that there are quite striking levels of other toxic elements, such as manganese and boron in some parts of the island.

‘Again, these small amounts of data maybe be hinting at greater underlying issues and ones that could for example be affecting the health and development of small children which can occur in the presence of high manganese levels.’

He also raised concerns about other contaminants such as bacteria and viruses derived both from effluent disposal and agriculture, as well as from the break down products of common pharmaceuticals and detergents used year after year, which may reach the ground water.

‘The Sark Government has a responsibility to demonstrate that there is a supply of healthy uncontaminated water which reaches standards comparable with the other neighbouring islands and which are broadly comparable with standards found throughout the UK and Europe.’

Chief Pleas is being asked to approve up to £5,000 for a hydrogeological scoping study.