What’s in the water you drink?

Well water testing clinic – Aug. 18-19 at Scandia Community Center

Groundwater provides 100% of the drinking water in Washington County and 70% of drinking water statewide. Over the past several years, a number of groundwater contamination issues have developed in the east metro area, leading many people to wonder, “Is my water safe to drink?”

The Minnesota Groundwater Contamination Atlas contains an interactive map of known contamination sites in the state: www.pca.state.mn.us/data/minnesota-groundwater-contamination-atlas.

For homes connected to a municipal water supply, this is a relatively easy question to answer. Cities test their water supplies regularly and provide a Consumer Confidence Report online that details monitoring results for ten different contaminants. For homes with private wells, however, it is up to homeowners to test their water regularly for common contaminants such as E. coli, nitrate, and chloride. 

Eight years ago, Washington Conservation District worked with Minnesota Department of Agriculture (MDA) and local landowners to sample well water from 504 homes in southern Washington County – 280 in Cottage Grove and 224 in Denmark Township. Of the samples tested, 29% of those in Cottage Grove (80 total) and 13% of those in Denmark Township (30 total) had nitrate levels above the standard set by the Environmental Protection Agency (more than 10 mg/L).

Learn more about Minnesota’s nitrates township testing program at www.mda.state.mn.us/township-testing-program.

The biggest risk associated with elevated nitrates in drinking water is a disorder called “blue-baby” syndrome, or methemoglobinemia. It affects infants younger than six months old that drink formula mixed with the water and can pose a risk to pregnant women as well. Blue-baby syndrome reduces the oxygen carrying capacity of blood and babies suffering from the illness might turn bluish in color, develop long-term digestive or respiratory problems, or even die.

More recently, a growing body of scientific evidence suggests that elevated nitrates may cause health impacts for adults as well, including increased heart rate, nausea, headaches, and abdominal cramps. Some studies also suggest an increased risk of cancer, especially gastric cancer, associated with dietary nitrate/nitrite exposure, but there is not yet scientific consensus on this question.

Part 1 of the Groundwater Protection Rule restricts the application of nitrogen fertilizer in the fall and on frozen soils in areas with vulnerable groundwater – photo from MPCA

The Minnesota Pollution Control Agency has found that 3 billion pounds of nitrogen enter our lakes, rivers and groundwater from fertilizer and nutrient-rich soil every year. The amount of nitrogen flowing downstream into the Mississippi River has doubled since 1996 and small towns across Minnesota are grappling with increasing levels of nitrates in their drinking water supplies.  

In 2020, Minnesota enacted a new rule that restricts the application of nitrogen fertilizer in the fall and on frozen soils in areas with vulnerable groundwater, to help address the growing concerns about nitrate contamination. The Groundwater Protection Rule applies to approximately 12-13% of Minnesota’s cropland and nearly half of the land in Washington County. Washington Conservation District is also partnering with Minnesota Department of Agriculture and landowners in southern Washington County to promote nitrogen fertilizer best management practices, develop nutrient-management plans, and implement cover crops and perennial crops to reduce the need for nitrogen fertilizer.

On Aug. 18-19, Carnelian-Marine-St. Croix Watershed District will provide free testing of nitrate and chloride in drinking water during a Well Water Testing Clinic at the Scandia Community Center (14727 209th St N, Scandia). The clinic is free and open to everyone, including people who live in Wisconsin.

To participate, bring drinking water from your home (minimum of one cup – 8oz) in a clean, hard plastic or glass container and include the location and date that you collected the sample. Drop off samples from 1-6pm on Thursday, Aug. 18. You can wait for your results, request them via email, or come back on Friday, 4-6pm to discuss your results with an expert.

During the clinic, experts will also be on hand to discuss other groundwater issues in the region, including arsenic, pesticides, and Perfluorinated Alkylated Substances (PFAS). Stop by anytime to pick up fact sheets and talk with clinic volunteers, or attend one of the scheduled presentations:

  • Watershed Hydrogeology, with Stu Grubb, EOR, Inc. (3pm & 4pm on Thursday, Aug. 18)
  • Groundwater Issues, with Angie Hong, East Metro Water Education (3:30pm & 4:30pm on Thursday, Aug. 18)

Co-sponsors for the Water Testing Clinic include Washington County, East Metro Water Education Program, Minnesota Groundwater Association, and the Minnesota Well Owners Organization.