What’s in the water?: A look at the city’s drinking water
Editor’s note: This is the first part of a two-part story examining Perham’s water. This article focuses on nitrate levels in the drinking water, while the second part of the story, to be published in next week’s Focus, will look at groundwater levels.
Perham’s drinking water is safe, but vulnerable to contamination and prone to high nitrate levels.
The city was listed as one of 16 “groundwater areas of concern” in a new report by the Freshwater Society of Minnesota.
The drinking water meets federal standards, with no contaminants detected at levels that violate those standards. However, the Perham area’s sandy soils make wells susceptible to contamination, and nitrate levels have been closely monitored for years.
The report, released in April, is called “Minnesota’s Groundwater: Is Our Use Sustainable?” It mainly looks at groundwater availability, but also identifies places where issues of groundwater quality have arisen in recent years.
Perham is one of those places, along with Park Rapids, Bemidji, White Bear Lake and a dozen other cities around the state.
The Minnesota Department of Health describes Perham’s five city wells as having high aquifer sensitivity due to “the local geological setting.”
The most common causes of nitrate in drinking water are runoff from fertilizers, leaching from septic tanks and sewage, and erosion of natural deposits. Coarse, textured soils like those found around Perham exacerbate the problem, as they have poor water holding capacity.
Data from the Minnesota Rural Water Association shows that Perham’s nitrate levels have hovered around 5.5 parts-per-million (ppm) over the last several years, as a rough average. The maximum limit allowed by law is 10.4 ppm.
In 2011, the nitrate level of the water in at least one of Perham’s city wells reached 7.9 ppm, according to a Drinking Water Report issued by the city.
“A good way to explain the nitrate concerns is to say it’s like high blood pressure,” said Aaron Meyer, a groundwater specialist with the Minnesota Rural Water Association. “Perham’s ground water is like high blood pressure in that it’s elevated and the city needs to watch it to make sure it doesn’t go over.”
“Seven is higher than it should be,” Meyer added. “We want to work now to keep it from being 10.”
The state departments of health and agriculture have long worked with Perham to address nitrate contamination in the area’s groundwater. Nitrate test results have been compiled regularly since 1993, according to the city’s Wellhead Protection Plan, and it wasn’t uncommon for city wells to test near the safe drinking water standard in those earlier years.
The Wellhead Protection Plan was initiated in response to this. The plan includes goals to:
-Reduce the level of nitrates to 5 ppm or less;
-Establish general public awareness and education on groundwater and drinking water protection issues;
-Establish a funding source for wellhead protection, and;
-Maintain a groundwater protection strategy which addresses all potential contaminants, along with strategic long range planning for growth.
This plan, last revised in 2005, is due to be reviewed and amended again within the next couple of years.
The plan was created with input from several state, regional and local agencies and individuals, including a then-newly-formed Wellhead Protection Committee.
George Kupferschmid is on that committee, and has been since it started. One of the committee’s roles today, he said, is to take water samples twice a year from wells inside the Wellhead Protection Area, which includes Perham and a large footprint of land east of town.
“We’re basically just testing for nitrates in our Wellhead Protection Area, which feeds the city wells,” he said. “We’re a first warning light.”
The East Otter Tail Soil and Water Conservation District also collects water samples. District Manager Darren Newville said that, since the 1960s, samples have been collected once a month from more than a dozen wells within the district. The data from that monitoring is provided to the Minnesota Department of Natural Resources.
If any well shows nitrates above the standard, it will be temporarily shut down until the level has dropped, as stated in the Wellhead Protection Plan.
In recent years, though, nitrate levels have generally been on a downward trend, showing improvement since wellhead protection efforts began.
The educational component of the protection efforts may be making a difference, as landowners learn how to protect their water through proper turf management and lawn care, and fertilizer usage ‘best practices’ evolve. Research into the effects of agricultural chemicals on groundwater is ongoing by many agencies, which aim to help farmers grow strong crops while minimizing risk to the environment.
It also helped when Perham added a new high-capacity well in 2005. This well generally has a lower concentration of nitrates than the other, older wells, and the city mixes the water from this well with the others to dilute the total concentration of nitrate in the overall water supply.
In addition to nitrate, monitoring done on the city’s drinking water between Jan. 1 and Dec. 31, 2011, found trace amounts of barium, radium, fluoride, haloacetic acids, chlorine, copper, lead and trihalomethanes, according to Perham’s 2011 Drinking Water Report. These were all well below the maximum limit allowed by law.