Minnesota Tackles Drinking Water Safety

OMAHA (DTN) -- Nitrate pollution in water is becoming a growing threat in Minnesota at a time when state lawmakers are considering legislation that could require farmers to install buffer strips along streams and other waterways, according to a new drinking water annual report from the Minnesota Department of Health this week.

Although the state said it has seen no communities in violation of the federal Safe Drinking Water Act in 2014, the number of communities investing in infrastructure to filter nitrate is growing.

"Since 2008, the number of community public water supply systems with nitrate treatment has increased from six to eight," the report said. "This change also means that the number of people served by systems actively treating for nitrate has increased from approximately 15,000 to 50,000 people. Three of those systems also blend in combination with treatment. One additional system only blends to reduce nitrate at this time."

Minnesota agriculture industry groups have expressed opposition to a bill offered by Democratic Gov. Mark Dayton that would require 50-foot buffers across the state. Farm groups say they are not opposed to the use of buffers, but object to what they say is a one-size-fits-all approach.

The report said in 2014 about 10% of non-community systems in the state have groundwater sources affected by surface contaminant sources that discharge nitrate.

About 105 non-community systems had water sources with nitrate at or above the maximum contaminant level of 10 milligrams per liter. About 230 had sources at or above 5 mg/L, and about 260 had sources at or above 3 mg/L.

"The financial impact of fixing the problem can be a strain on small business owners," the report said. "For example, if each of the 105 water systems at or above the nitrate MCL needed to invest $10,000 to replace the source (drilling a new well), install treatment, or connect to city water, the systems would represent $1.05 million in capital investment. This cost does not represent operation and maintenance costs or for systems that are required to employ a class D water operator.

"The data show that nitrate is affecting source water quality and has an economic impact on the system owners. There is also an economic impact on the state, as well. It takes additional resources to manage the water quality of those systems."
About half of Minnesota's land is in agricultural production, primarily in the southern and western parts of the state. That includes up to 20 million acres in annual row-crop production including corn, soybeans, sugar beets, and potatoes.

"However, since soils in row-crop production can lose nitrate during the non-growing season, these lands are the biggest influence on Minnesota's ground and surface water nitrate levels," the state report said.

FILTERING EFFORTS

The MDH study focused on the efforts of a number of state communities to improve drinking water.

The southern Minnesota town of Edgerton in Pipestone County has had a "roller-coaster ride with nitrate over the past 25 years," the report said.

"The flux of nitrate levels in this community tells the story of how global economic forces affect drinking water protection here in Minnesota. Nitrate has been a growing problem for Edgerton since the 1980s, and in the late 1990s the city had to construct a water treatment plant to provide safe drinking water ... Edgerton's approach focused on limiting agricultural sources of nitrate by encouraging innovative fertilizer application practices."

In addition, the report said the city of Edgerton "heavily promoted" the Conservation Reserve Program as a key aspect of reducing nutrient runoff.

"Alternative land uses were popular among landowners at the time because crop prices were relatively low," the report said. "As management measures took hold, nitrate levels in source water declined by approximately 50%."

When corn prices began to increase above historical levels around 2005, the report said, many farmers in the Edgerton area went away from CRP as incentives were "no longer a match" for agricultural production.

"Much of the land previously enrolled in the Conservation Reserve Program reverted to row-crop production," MDH said. "At the same time, nitrate levels in groundwater rapidly increased, along with the financial burden of treatment plant operation. Global crop-market trends drive agricultural land uses. Edgerton has been hit especially hard by this reality. Unlike many communities, the city has only one viable source of groundwater, a source that is highly vulnerable to contamination due to the type of soil and how close the water is to the surface."

The report also highlighted the challenges in the southwestern Minnesota town of Worthington known for the 880-acre Lake Okabena.

The MDH said surface water is important to the city as groundwater is difficult to find for the city's 12,000 residents.

Since 2006, the city and other local partners have contributed nearly $2 million to help set aside 520 acres of agricultural land for conservation. The report said that in 2014, the city bought a 150-acre parcel of land where "groundwater is particularly vulnerable and connects to other existing conservation areas."

HUMAN HEALTH, NITRATES

The report makes the connection between nitrate levels in Minnesota communities and human health concerns.

A Minnesota Department of Health study found 146 cases of methemoglobinemia in infants, mostly in southwestern Minnesota, that resulted in 14 deaths from January 1947 to July 1949. "Once the medical community learned of the relationship between methemoglobinemia and nitrate, the number of cases dropped from 129 in 1947 to 12 in 1949," the report said.

The report said Minnesota communities have one of the best records in the country when it comes to complying with testing requirements set out in the Safe Drinking Water Act.

The report said that in 2014, MDH found no violations of the federal act when it comes to pesticides and other industrial contaminants in 20,946 tests conducted on community water systems.

Read the report here: http://tinyurl.com/…

Todd Neeley can be reached at todd.neeley@dtn.com
Follow him on Twitter @toddneeleyDTN

(SK/AG)

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