SUMMER 1999
2305 East
5th Street
Duluth Minnesota 55812 -1445
arsenic
in minnesota's drinking water
Map by Minnesota Pollution Control Agency Ground Water Monitoring and Assessment
Program |
What is arsenic?
Arsenic is a tasteless and odorless element that occurs naturally in rock
and soil and can be present in ground water. Drinking water or eating food contaminated
with arsenic exposes humans to this substance. Less commonly, mining, petroleum
refining, manufacturing, and the leaching of pesticides and wood preservatives
can contribute to arsenic contamination in ground water.
What are the
health effects?
Continued exposure to arsenic can lead to skin, circulatory,
and nervous system problems. Symptoms may include nausea, vomiting, diarrhea,
decreased production of red and white blood cells, abnormal heart rhythm, blood
vessel damage, or a "pins and needles" sensation in hands and feet. Long-term
exposure to high levels of arsenic also increases a person's risk for skin cancer.
Ongoing research investigates the possible links between arsenic and liver, kidney,
lung, and bladder cancers in humans.
What are the recommended levels for
drinking water?
The current drinking water standard for arsenic set by
the Environmental Protection Agency (EPA) is 50 micrograms per liter (µg/L) which
is the same as 50 parts per billion (ppb). However, the EPA may lower this standard
in January 2001 to a level between 2 and 20 µg/L based on future research results.
Does arsenic exist in Minnesota?
Yes, although most arsenic levels
in Minnesota's ground water are below the EPA's drinking water standard. The Minnesota
Pollution Control Agency studied 954 primarily domestic wells in Minnesota between
1992 and 1996 for levels of potentially harmful chemicals, including arsenic.
The map above plots arsenic concentrations for the Minnesota wells tested by the
study.
What should I do?
If you receive drinking water from municipal
utilities, you can call your local utility and ask about the level of arsenic
in your water. Public water utilities are required to test for arsenic. If you
have a private well, especially one that may be at risk for a high arsenic level,
you may want to consider having your water tested for arsenic by a certified lab.
Arsenic tests cost approximately $30.
What can I do about arsenic in my
drinking water?
If the level of arsenic in your drinking water is between
2 and 50 µg/L, the Minnesota Department of Health (MDH) recommends that you consider
some of the available methods for reducing arsenic exposure. You may want to install
a reverse osmosis or distillation unit, drill a new well, or use bottled water
for drinking and cooking.
For more information:
Call the MDH at
651.215.5800 for more information about arsenic in your drinking water. If you
are a Web user, find more details about arsenic at http://www3.extension.umn.edu/water/arsenic.html.
question of the season
Why should I be concerned about water use in a water-rich
state like Minnesota? This is an important question that most of us who
live in the land of 10,000 lakes shrug off. However, there are compelling reasons
why you should be concerned about individual water use. About 60% of Minnesotans
obtain their water from ground water and in certain parts of the state this resource
is starting to show signs of stress. In the last 30 years the water level in the
Mt. Simon aquifer near Savage, Minnesota, has dropped nearly 60 feet. Demographers
predict that the population of the Twin Cities Metropolitan area will continue
to grow. With the influx of new residents, the need for water conservation will
be even more critical.
Why should I be concerned about our ground water
levels?
One of the most obvious reasons is so that we have enough clean
water for our future needs. Another reason relates to the connection between our
ground and surface waters. Most of our lakes, streams, wetlands, and other highly-prized
surface waters are fed by ground water. When we overdraw our ground water supplies
the lower levels will decrease the flow of fresh ground water to our surface waters.
As surface water disappears, fish kills occur in streams, critical wetland areas
dry up, and lake levels drop.
What can an I do to conserve water?
Many
things! Purchase water conserving fixtures and appliances, especially in the bathroom.
Flushing the toilet constitutes about 30% of our daily water use. Good low flow
toilets, shower heads, and other fixtures and appliances are on the market that
will not compromise your quality of life. Water your lawn only when needed and
try to water during the early morning when the potential for evaporation is the
least (lawn watering can more than double our water use during summer). In addition,
establish native vegetation on your property that does not need to be watered
frequently. Contact your local University of Minnesota Extension, DNR, or Soil
and Water Conservation District offices for further assistance. Lastly, support
local water conservation ordinances for your area. For more information on water
conservation and to obtain free water conservation fact sheets, contact the University
of Minnesota Sea Grant Program 218.726.8106.
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