Is arsenic a potential contaminant in your drinking water supply?

If you have a private drinking water well, checking with your local health department can alert you to potential contaminants in the drinking water in your area.

Arsenic is a metallic element that is part of the periodic chart. The problem is that it is colorless and odorless, so it cannot be detected without running lab tests. There are many natural sources of arsenic in the environment. It can exist naturally in earth materials such as bedrock, sand and gravel. Inorganic arsenic can make its way into the ground by being dissolved by and absorbed into drinking water withdrawn from groundwater supplies.

Arsenic in water used for drinking and cooking has been found to be harmful to human health. Fortunately, arsenic is not readily absorbed by the skin, so arsenic in drinking water used for washing and bathing is not a significant source of arsenic exposure to people.

Since arsenic is a natural part of the environment, there are other ways in which we can be exposed:

The United States Environmental Protection Agency (EPA) has set the maximum contaminant level (MCL) for arsenic in drinking water as .010 parts per million (ppm). The recommended arsenic drinking water health advisory is also .010 ppm. However, some areas of Michigan have been identified as having unsafe levels of arsenic in drinking water.  Water quality maps for Michigan and certain individual counties showing concentrations of arsenic and other contaminants affecting drinking water are available from MDEQ.

The effects of arsenic on humans include thickening and discoloration of skin, stomach pain, nausea, vomiting, diarrhea, numbness in extremities, and partial paralysis. Arsenic also has also been linked to several types of cancers. The exact health risk that may result is determined by many factors including dose, duration, type of arsenic, and general condition of the affected person.

If you suspect you might have arsenic in your drinking water, or if you are not sure if it is a problem in your private water supply, Michigan State University Extension recommends that you contact your local health department or the MDEQ Drinking Water Analysis Laboratory. They will help you determine if you should have your water tested. Note that arsenic testing is not a test routinely performed on private wells unless specifically requested. Depending on the results, you will be advised of your options to reduce your arsenic exposure, whether it is connecting to a community water supply system, switching to bottled water, or utilizing a specific type of water treatment system.