Nine out of 10 private wells tested in the Ivy Lake-Devine corridor have tested positive for arsenic.
The wells tested by the Vancouver Coastal Health Authority (VCHA) showed levels higher than the Health Canadas acceptable level of 10 parts per billion (ppb), in one case the reading was 57 ppb.
The tests did not involve any public water systems.
Arsenic is considered a human carcinogen. The associated health risks connected with exposure to this toxic chemical element include skin cancer and tumours of the bladder, kidney, liver and lung. Neurological effects, such as memory loss and concentration problems, are also symptomatic of exposure. Some evidence has linked cardiovascular disease and diabetes to the poisonous semi-metallic element.
This concerns Cindy Watson, an environmental health officer for Vancouver Coastal Health Authority. Watson wants residents in the affected area to be aware of the importance of testing their wells.
"Typically this is a concern with deep wells but arsenic sometimes shows up in shallow wells," she says.
There is no smell, taste or discolouration associated with water contaminated with arsenic. The substance is naturally occurring in the earths crust in areas where there has been past volcanic activity.
"When a well is drilled through igneous rock, it goes through the cracks and fissures and picks up stuff," explains Bob Weston, chief environmental health officer for VCHA. "Igneous rock is not a typical aquifer. The water fills the gaps and spaces in the rock. This is why one property can have high levels while a neighbouring property can have none at all.
"I suspect we would also find arsenic in the Meager Creek area or any other with geothermal activity."
Arsenic can also enter the water via the discharge of industrial byproducts. For example, arsenic particles can get into the environment through the burning of fossil fuels and metal production (such as gold and base metal mining). Arsenic also enters water tables via agricultural use, as it is used in pesticides and feed additives.
Neither Watson nor Weston could estimate how long arsenic had been a problem in the area. But Watson said she had heard anecdotal evidence of long-term residents being aware of the problem for "quite some time". Why it was not reported remains unclear. However, the presence of arsenic in well water can have an adverse effect on decisions to allow for the subdivision of a property.
In the early 90s, arsenic was found in wells on Bowen Island, the Sunshine Coast and the Gulf Islands, so there was an awareness of the issue as it applied to well users. The Ivy Lake-Devine corridor wells had once been tested under a now-defunct government subsidized program. However, arsenic was not one of the contaminants that the test screened. With only anecdotal evidence available, it is impossible to ascertain how long arsenic has been present in the area wells.
The good news is that there are several systems available for removing arsenic from water sources. The cost of treatment options varies greatly, pricing dependent upon the size of system and the volume of water to be treated. Many people opt for having only drinking water treated, which can be accomplished with affordable "point of use" (POU), treatment equipment. Others may opt for more expensive "point of entry" (POE) systems that treat all the water used in a home.
The VCHA has a list of criteria that it urges homeowners to consider before investing in a system. This list can be accessed through the agencys website at: www.vcha.net/main/home.asp.
However, residing in an area where arsenic has been found doesnt mean that a treatment system is an immediate necessity. Because of the aforementioned atypical aquifers, arsenic contamination can never be a forgone conclusion.
Both Watson and Weston agree that the first thing well users should do is have their water tested through an accredited lab. For generally less than $250, complete water safety testing can be done. Weston suggests that new wells should be tested upon completion and at six months.
"Initial pump tests may not be representative," he warns, adding that arsenic levels tend to fluctuate.
After the first year, annual tests should be conducted for three or four years.
"If the levels look stable, then I would test every two or three years just to be cautious," said Weston.
Water testing can generally be completed within a one- to two-week period.
For explicit directions on coordinating a self-test of well water check the VCHA website.