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


Drinking Water

Distillation to Remove Arsenic from Drinking Water

What is distillation?

Distillation units boil the water, gather the steam, and cool it to turn it back into water. The heat kills bacteria. The mineral, metal and other contaminants, including arsenic, stay in the boiler. It results in nearly pure water.

Where should the distillation unit be installed?

Distillation units can be installed at the point-of-use. 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.

Does raw water quality affect how well the distillation unit works?

Raw water quality will not affect how much arsenic the distillation unit can remove from drinking water.

How effective is distillation?

Distillation units are capable of removing virtually all the arsenic from the raw water.

How practical or difficult is the distillation unit to operate and maintain?

The distillation unit is simple to operate and practical for household use. Maintenance includes cleaning the boiling chamber and the heating coils from time to time.

How much does the distillation unit cost?

You can expect to pay from $2000 to $2500 (2004 prices) for a point-of-use distillation unit.

How much does it cost to operate and maintain a distillation unit?

The only operating cost is electricity. Distillation units consume a relatively high amount of electricity. A typical point-of-use system may use about 0.9 kWh for every litre of water produced.

How long should the distillation unit last?

Commercial sellers report that the heating element and fan motor will probably need to be replaced every 10 years, depending on the raw water quality passing through the system. Scale build-up caused by hard water will reduce the life of the equipment.

What happens to the substances in the water?

They are left in the stainless steel boiling chamber, but cannot get into the treated water.

How much wastewater does the distillation unit create?

The unit makes very little wastewater, which can be flushed to your sewage disposal system when the boiling chamber is cleaned.

Does the distillation unit also remove other substances?

The distillation unit removes almost all dissolved substances you might expect to find in drinking water.

Does distillation have any side effects or drawbacks?

Water treated by distillation can be corrosive, however this is generally not a problem for households using the unit as a point-of-use device to treat drinking water. Some people find that the unit is too noisy to use under the kitchen sink.

Distillation units do not produce large quantities of treated water in a short period of time.

For some consumers, distilled water may have a bland taste due to the removal of all minerals. As well, distillation units remove beneficial minerals such as calcium and magnesium. It is important to consume a reasonably well-balanced diet to offset the removal of these minerals.

Are there any manufacturers that make a better unit?

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 NSF Standard # 62 - Drinking Water Distillation.

Where can I get a distillation unit?

Units are available from water treatment companies in Nova Scotia. Check the Yellow Pages of your telephone book under the heading Water Treatment for a list of water treatment dealers.