A HEALTH warning has been issued after a man in Grasmere is believed to have sustained naturally occurring arsenic poisoning after drinking from his private borehole supply.

Recent sampling by South Lakeland District Council (SLDC) has discovered high levels of the potentially poisonous metal in several private supplies.

SLDC confirmed there had been a case on National Trust land in Grasmere where officers sampled for arsenic after finding that a borehole that had not been tested was being used for a private water supply.

The samples showed elevated arsenic levels and the borehole was disconnected and replaced with a nearby spring supply.

The maximum legal limit in drinking water is 10 micrograms per litre (ug/l) – but levels of up to 100ug/l have recently been detected from some boreholes in the district.

Arsenic poisoning can lead to sickness, diarrhoea, skin problems, headaches and even paralysis.

A SLDC spokesperson said the contaminated borehole in Grasmere was disconnected “prior to a possible link between the person’s illness and a private water supply being suggested.”

They went on to say that “no direct link between the person’s illness and a water supply has been established.”

But the case has prompted a warning for people with private water supplies to ensure they test them regularly.

High levels of arsenic can be removed from a contaminated supply once it has been identified.

But a SLDC spokesperson said: “Prevention is always better than cure and if anybody is on a private water supply then it is important that they are fully aware of where their water comes from and also that it is safe to drink. The supply should also be tested regularly.’’

There are more than 1,600 known private water supplies in South Lakeland, around 150 of which are believed to be boreholes.

Arsenic is a naturally occurring metal in the ground and SLDC confirmed that boreholes within the district were more likely to be contaminated by arsenic ‘due to the geology of the area’.


Dr Ken Lamden from Cumbria and Lancashire’s Public Health England team said: “Because arsenic is so widespread in the environment, it is not unusual to find it at very low levels in some private drinking water supplies.

“Long-term exposure to relatively high levels of arsenic in drinking water could produce skin lesions, such as moles, cysts, warts or skin tags that appear as darker areas of skin and have the appearance of small ‘corns’ or ‘warts’ on the palms, soles of the feet, and chest or back.

“Anyone who has been consuming water from the affected supply and has adverse effects consistent with excessive arsenic consumption may wish to seek advice from their GP.”

The International Agency for Research on Cancer has determined that inorganic arsenic (the form most commonly found in water) can cause cancer of the lung, skin and bladder.

A National Trust spokesperson said: “We take matters such as this very seriously. We are fully committed to water cleanliness, investing in both projects that tackle pollution directly and in land management solutions that prevent pollution occurring.”