Arsenic in Michigan Well Water

Michigan Well Water and Arsenic

Impurities in well water like pesticides, lead and even radon get a lot of press.

But something else may be lurking in your Michigan well water... arsenic.

What is Arsenic?

Arsenic is a naturally occuring metal, found in rocks and soil, water, air and plants. It is also odorless and tasteless.

It is also used in industry, most popularly as a wood preservative, but also in paints and dyes, certain fertilizers, as well as mining and coal burning operations.

A compound of arsenic and hydrogen or carbon is called a organic arsenic, and often found in fish or plants. But this compound isn't as dangerous to humans.

Inorganic arsenic, which is arsenic in compound form with oxygen, chlorine, or sulfur, is both much more dangerous to human health, and the type of arsenic found in Michigan's well water.

Dangerous Levels

Ground water sources (like wells) contain more arsenic than surface waters like lakes or rivers. In Michigan, there are geographic "hot spots" that have higher levels of arsenic in the rock formations (see the map).

The Environmental Protection Agency set the arsenic standard for drinking water at 10 parts per billion (it used to be 50 ppb, but was lowered to 10 ppb in 2006) for public water systems. But well water systems are private, and it is up to each well owner to have the water tested for arsenic or other contaminants.

Note that 10µg/L on the map above is read as "ten micrograms per liter" and equals 10 parts per billion. That means Oakland, Lapeer and many of the "Thumb" counties may have well water containing arsenic at over five times the EPA limit.

Exposure and Health Problems

Exposure to arsenic is known to cause both short- and long-term health effects. Short (or acute) effects can occur within hours or days of exposure. Long (or chronic) effects occur over many years.

Short-term effects include:

• Nausea, vomiting, and diarrhea
• A "pins and needles" sensation in hands and feet

Long-term exposure to arsenic has been linked to:

• Decreased production of red and white blood cells
• Abnormal heart rhythm
• Blood vessel damage
• Cancer of the bladder, lungs, skin, kidneys, nasal passages, liver and prostate
• Thickening and discoloration of the skin
• Stomach pain
• Numbness in hands and feet
• Partial paralysis
• Blindness

So this is serious stuff we are dealing with.

What Do I Do About This?

For Your Well Water:

Remember that public sources of water are tested regularly. Private sources of water are the responsibility of the well owner.

During well construction and normal water sampling, the water is usually not tested for arsenic. Your local health department can provide a list of certified state and commercial laboratories that for a fee will test for arsenic in your water.

For Your Body:

There are a few medical tests you can have performed, if you are concerned about the level of arsenic in your body, but they are beyond the scope of this post.

What Should I Do If My Arsenic Level Tests High?

In the interim, stop using your well water for drinking and preparing food and switch to bottled water in the short-term. However, for showers and hand washing, you should be fine, since skin contact with water containing arsenic will not result in significant exposure.

If a connection to a public water supply isn't possible, you may want to consider options like reverse osmosis (RO) or distillation. Devices for either method need ongoing maintenance, and RO in particular requires periodic filter replacement.

Water softeners and activated carbon filters do not reduce arsenic levels effectively.

Michigan counties have some great health departments, and they will be glad to answer any questions you have about your well water... or refer you to the right people to speak with.