Nitrate levels in Nebraska’s groundwater are on the rise, especially in portions of Northeast Nebraska. The Lower Elkhorn Natural Resources District (LENRD) has analyzed the nitrate data gathered as part of the routine Groundwater Quality Sampling Program and have found some troubling trends across their 15-county district.
An evaluation of water quality data collected over the past 40 years reveals that nitrate concentrations are continuing to increase in some areas. Most recently, the data indicates elevated concentrations of nitrate in portions of Cuming, Colfax, and Dodge Counties, reaching levels that could pose health threats to humans and the environment.
While the most serious threat from excessive groundwater nitrate is to human health, environmental issues such as harmful algae blooms in lakes are caused or exacerbated by excessive nitrate loads in Nebraska’s waters. Nitrate is often found in surface water, like rivers and lakes, but it also readily travels into groundwater supplies, meaning that no source of drinking water is safe from potential nitrate contamination.
What is nitrate and how does it end up in our water?
Nitrate is found naturally in the environment; however, evidence shows that excess nitrate comes primarily from the use of commercial fertilizers (both organic and manufactured). Nitrate dissolves readily in water and can easily transport beyond the root zone if unused by a growing crop to contaminate groundwater.
Nitrate Threshold in Drinking Water
The Safe Drinking Water Act requires that nitrate concentration in drinking water does not exceed 10 milligrams per liter. This threshold has been established to prevent methemoglobinemia (“Blue Baby Syndrome”) in infants. Pregnant women and adults with certain health conditions are also at increased risk for health issues.
Researchers working with the University of Nebraska Medical Center have published studies indicating that prolonged exposure to drinking water containing nitrate levels at or even below the threshold of 10 milligrams per liter is associated with increased risks of thyroid disease, central nervous system birth defects, and colorectal, bladder, ovarian, and stomach cancers, and therefore the threshold does not account for these other health effects.
Cancer ConcernsThere may be a link between nitrate contamination in drinking water and Nebraska’s high rate of pediatric cancer. Other studies show that the presence of both nitrate and atrazine could increase the chances of developing lymphoma.
Birth Defect ConcernsBirth defects in Nebraska are on the rise, occurring at a rate almost double the national average. The counties with higher rates of birth defects also have a higher rater of agrichemicals in the water. Could there be a link?
Is it just in our area? Is this a new problem?
No, there are many areas where there is an increased level of nitrate in the groundwater. However, nitrate is typically found in agricultural regions.
Nitrate currently found in wells may have arrived there years or decades ago. At the same time, agriculture and other sources continue to contribute nitrate to groundwater.
What Can We Do About It?
There is still time to act on the rising levels of nitrate in Nebraska’s groundwater. The LENRD is working around the clock to test and improve the quality of Nebraska’s groundwater while raising awareness of rising nitrate levels. There are steps everyone can take to reduce these nitrate levels. It takes all of us working together to ensure the best future for Nebraska.What Can We Do About It?