Government of Nova Scotia Government of Nova Scotia Nova Scotia, Canada


Drinking Water

Arsenic in Nova Scotia's Drinking Water

What is arsenic?

Arsenic is a natural element that can be found in the Earth's crust. Some areas of Nova Scotia have elevated arsenic levels in drinking water.

How does arsenic get into drinking water?

Arsenic gets into drinking water when groundwater dissolves minerals that contain arsenic. Elevated levels of arsenic are more likely to be found in drilled wells than in dug wells or surface water supplies. Arsenic may also enter water supplies from industrial effluents, pesticide runoff or from atmospheric deposits.

What are the health concerns of arsenic?

Ingestion of drinking water that has high concentrations of arsenic over a short period of time can cause sickness including nausea, diarrhea and muscle pain. Over the long term, exposure to low levels of arsenic may cause certain types of cancer.

How do I know if I have arsenic in my water?

You must test for arsenic to find out if you have it in your drinking water. A listing of labs in Nova Scotia that test for chemicals such as arsenic is available at Water Testing Labs.

What is the limit for arsenic in the Guidelines for Canadian Drinking Water Quality?

The limit for arsenic in the Guidelines for Canadian Drinking Water Quality was reduced to 10 micrograms per litre ( µg/L) in May 2006.

What can I do if the arsenic in my drinking water is above the guidelines?

If tests show that the amount of arsenic in your water is above the Canadian guideline, you can treat your drinking water, use another acceptable source of drinking water, or use bottled water from a supplier who is a member of the Canadian Bottled Water Association or International Bottled Water Association. Unlike some drinking water contaminants, boiling the water will not remove arsenic.

Can I use my carafe or pitcher style filter to remove arsenic?

No, carafe or pitcher style filters will not remove arsenic.

If I have arsenic in my water, can I still bathe in it?

Arsenic is not well absorbed by the skin. As a result, there is minimum exposure to arsenic as a result of showering or bathing. Children should avoid drinking bath water, however an occasional mouthful would not be considered a significant health risk because the guideline is based on drinking 1.5 litres per day for a lifetime.

If I have arsenic in my water, can I use it to water my vegetable garden?

Watering your garden with water containing elevated levels of arsenic should not pose a serious health risk. However, it is recommended that you maintain a high level of phosphorous in your soil because it has been shown to reduce plant uptake of arsenic.

How do you treat drinking water that has elevated arsenic?

There are several treatment processes that can be used to treat water with arsenic at the point-of-entry or the point-of-use. Some of the more common and effective methods include reverse osmosis, anion exchange and distillation. More detail on each of these processes can be found in individual fact sheets.

Other emerging technologies are showing promise for effective arsenic reduction. Examples include activated alumina and other adsorption media. However, with all treatment technologies, consumers should only purchase systems that have been certified by an accredited certification body as meeting the appropriate National Sanitation Foundation (NSF) International standards.

What do the terms 'point-of-entry' and 'point-of-use' mean?

Point-of-entry means that the treatment unit is installed where the water enters the home or building. All water used within the home or building will be treated. Point-of-entry systems tend to be larger and more expensive.

Point-of-use means that the treatment unit is installed at the tap where the water is being used for drinking, cooking and dental hygiene. Only water used from this tap is treated. Water from the remaining taps will not be treated and should not be used for drinking, cooking, or dental hygiene.

How do I know if my treatment system is working?

All treatment systems should be operated as per the manufacturer's instructions and be properly maintained. Both raw and treated water should be regularly tested for arsenic to ensure that the device is working properly.

Are there certain brands that work better than others?

Nova Scotia Environment does not recommend specific brands of treatment devices. However, it is strongly recommended that consumers use devices that have been certified by an accredited certification body as meeting the appropriate NSF standards. Homeowners should consult with a reputable water treatment specialist to determine the best equipment for their homes.

How can I find out more information?

Call the nearest Nova Scotia Environment office at 1-877-936-8476.