Do you have a well? How long has it been since you had your well water tested for nitrates?
You may not think you’re at risk, but it can happen.
Nitrates, which are found in fertilizers and also are formed during the decay of sewage and animal wastes, are the most common contaminants in Minnesota groundwater.
Most private wells in Washington County are safe. But in Cottage Grove and Denmark Township, where limestone bedrock makes it easier for pollutants to leach into groundwater supplies, studies have found elevated levels of nitrates in some wells.
In other parts of the county, shallow, poorly constructed or improperly located wells are also susceptible to pollutants.
On May 8, Washington County and the Washington Conservation District will offer a free well water testing clinic from 3 to 7 p.m. at the Scandia Community Center. During the clinic, staff will analyze water samples for nitrate levels and give people their results in about five minutes.
The biggest risk associated with elevated levels of nitrates in drinking water (at or above 10 mg/L) is a disorder called “blue baby” syndrome, or methemoglobinemia. This affects infants younger than six months old who drink formula mixed with the water. It can pose a risk for pregnant women as well.
Blue baby syndrome reduces the oxygen-carrying capacity of blood. Babies suffering from the illness might turn bluish in color, develop long-term digestive or respiratory problems, or even die. Parents may think they can clean up the water, for example by boiling it. But boiling, softening and filtration—which can solve other water pollution problems—do nothing to reduce nitrate levels. In fact, boiling can actually increase nitrate concentrations.
Blue baby syndrome is most common in rural areas where nitrates from fertilizers and barnyard runoff leach into the groundwater. Unlike other contaminants, nitrates are not diluted and filtered out as water travels through soil, so it is critical that wells are sited at least 100 feet away from septic systems, feedlots and agricultural drainage areas.
Even if you don’t have a baby and aren’t planning to get pregnant, Washington County’s Department of Public Health and the Environment recommends that you have your well water tested annually for total coliform bacteria and nitrates. Although nitrates do not pose a risk for adults, they can be a warning sign. Finding elevated nitrate levels in drinking water may indicate the presence of other contaminants such as disease-causing organisms or pesticides.
To participate in the free testing clinic on May 8, bring at least ½ cup of water in a clean plastic or glass container. To get a good sample, let the tap run five to 10 minutes before filling the container. If you have a distillation unit, reverse osmosis or other nitrate removal system, take two water samples, one before and one after the treatment process, to determine whether your system is working properly. If you have just a water softener, take just one sample.
Samples should be taken no more than 24 hours before the testing clinic and must be kept refrigerated prior to testing. To ensure accurate results, mark the container with your name and phone number. If more than one well is sampled, include a well identification number. It is not necessary to provide information about the well depth or location.
For a fee, Washington County also offers other well water tests. The basic test for drinking water quality, which includes coliform bacteria and nitrates, is $44. Tests are also available for hardness and other common minerals. Water samples can be dropped off at the Forest Lake North Service Center on Tuesdays from 8 to 10 a.m. To order a test kit, call 651-430-6655. Learn more at www.co.washington.mn.us/index.aspx?nid=637.
For questions about the free nitrates water testing clinic on May 8 or how to take a sample, contact Wendy Griffin at 651-275-1136 X24.