Portage County water study finds nitrates above safe levels in quarter of wells

STEVENS POINT - Nearly a quarter of tested wells in Portage County exceed safe drinking water standards for nitrates, according to a new county study.

In response, the county will hold four informational sessions for residents to learn more about how the research personally affects them and have their water tested for nitrates.

The first session will be at 6:30 p.m. Wednesday at the Central Wisconsin Electric Cooperative in Rosholt.

The study was conducted as a partnership of Portage County and the University of Wisconsin-Stevens Point Center for Watershed Science and Education. It looked at a number of components to water quality. One of its many findings included that about 24 percent of the wells tested exceeded the state and federal government’s safe drinking threshold of 10 milligrams of nitrate particles per liter, with one sample reaching more than four times that amount.

SEEKING SOURCES: How Portage County water quality affects you

The percent of tested wells that exceeded the standard is about two and a half times greater than the Wisconsin average of about 9 percent, according to Kevin Masarik, groundwater education specialist at UWSP's watershed science department.

Nitrates are a compound made of nitrogen and oxygen. They occur naturally in plants and vegetables at varying levels, according to the Wisconsin Department of Natural Resources, and are found in the fertilizer and manure applied to crop fields.

The study indicates strong evidence that the main drivers of nitrates contamination are vegetable farming and soil type — how well it drains and what it’s made of.

Consuming water — through drinking or cooking — that contains nitrates above the safe drinking limit is not safe for any infant or woman who is or may become pregnant, according to the Wisconsin DNR. The government also advises against long-term consumption of nitrate-contaminated water.

Infants less than 6 months old who consume nitrate-contaminated water are at risk of developing "blue baby syndrome," where nitrates reduce their blood’s ability to carry oxygen and can cause coma or death.

Some scientific research indicates that consuming such contaminated water in the first weeks of pregnancy may cause certain birth defects, but further research is needed, according to the DNR.

Scientists also suspect that nitrate-contaminated water may increase chances of thyroid disease, diabetes and certain types of cancers, according to a DNR fact sheet.

“These are actions we have done to our very own water in our very own county, right here in Portage County,” County Executive Patty Dreier said at the study’s unveiling this month. “Yes, I believe the state has been remiss in stepping up on some of their responsibilities regarding water quality. But I believe the opportunity is before us to make a fabulous example of ourselves to take this information and lift from it some actions that make a difference.”

Researchers surveyed more than 200 drinking water wells in the county last summer. It was the first comprehensive study of well water in the county’s history and acts as a benchmark for future research, Jen McNelly, Portage County water resource specialist, said.

The 2018 county budget includes $5,000 for future study of water quality in Portage County, with the idea being that the county would set aside some money each year for the next study, Dreier said.

The study also found:

About 40 percent of tested wells fell below 1 milligram of nitrates per liter, which is considered the natural, or background, level of nitrates in groundwater.

Average nitrate level in the county was about 6.5 mg/L.

Eastern Portage County has harder drinking water and Western Portage County has softer, more corrosive drinking water.

About 46 percent of drinking wells tested showed natural levels of chloride.

Informational sessions: