The Lower Loup Natural Resources District (LLNRD) is reminding Nebraskans in its region that nitrates in groundwater remain an ongoing concern. Nitrates in groundwater can’t be seen, smelled, or tasted. LLNRD reports that thousands of Nebraskans unknowingly consume nitrates every day through contaminated drinking water.
While municipal wells are required by law to be tested periodically, there is no requirement for testing for private domestic wells. LLNRD reports though that test kits can be obtained by Nebraskans for private use.
How do nitrates get into Nebraska’s water?
Per the LLNRD report, nitrates occur naturally, but human activity may elevate the compound to harmful levels. Most of the nitrates in our drinking water come from fertilizer applied to farm fields.
Nitrates also enter water supplies from industrial sources, and from fertilizer runoff from golf courses, park areas, and lawns.
University of Nebraska research leads to nitrate fingerprinting
While no one wants to be viewed as responsible for excess nitrates in groundwater, there is a scientific way to determine nitrate sources. Researchers at the Nebraska Water Center’s Water Sciences Laboratory, part of the University of Nebraska’s Daugherty Water for Food Global Institute, have developed a method of measuring nitrates and determining their source. Through a process known as “isotropic fingerprinting”, nitrates can be traced to organic sources like manure, or to commercial fertilizers.
Daniel Snow is the director of laboratory services at the University of Nebraska’s Water Sciences Laboratory. Per Snow, the majority of nitrate in Nebraska groundwater with elevated concentrations originates from commercial nitrogen fertilizer, based on stable isotope testing.
Snow states, “There are places, for example in the Lower Loup NRD, where we see evidence for organic nitrogen (manure, wastewater, etc.) sources which contributes to high groundwater nitrate. Overapplication of any nitrogen source (fertilizer or manure) in excess of plant needs will over time result in nitrate accumulation, leaching and eventually contaminate local groundwater.”
Lower Loup NRD research helps producers save money and reduce nitrate use
The LLNRD is working on an innovative study to monitor the movement of nitrates in various soil types, year-round. The study involves soil probing in fields where manure is applied as a nutrient, and also in fields where commercial fertilizer is applied.
Likewise, producers can perform their own soil tests. Soil testing allows farmers to determine how much residual nitrogen remains in the root zone, how much additional fertilizer to apply to get a crop through to harvest.
LLNRD is offering a cost-share program as an incentive for soil testing to encourage landowners to adopt advanced soil sampling analysis. The intent is to reduce nutrient input and improve soil health and water quality across the entire LLNRD.
To qualify, landowners must have certified irrigated acres and use an approved soil testing method. The LLNRD would then cost share up to $55 per soil sample, up to eight soil samples per year, for four years. Landowners with property within the Lower Loup NRD can sign up at their local Natural Resources Conservation Service office.
LLNRD urges Nebraskans to get their well water tested
LLNRD notes that while public water systems are required by law to be tested for contaminants, less than 4% of Nebraska’s 180,000 registered wells are tested annually, not including any unregistered wells across the state. According to the LLNRD, approximately 85% of Nebraskans rely on groundwater sources for their drinking water.
Residents who rely on domestic wells and want to know what their water contains can obtain testing kits from various labs in Nebraska, including the Department of Health and Human Services Public Health Environmental Lab.
LLNRD notes that installation of a reverse osmosis system can help bring contamination down to safe levels for some households. Depending on contaminant levels, others may need to drill a new well, rely on bottled water, or find another solution. Importantly, boiling water does not decrease nitrate levels.
LLNRD reminds its customers that Nebraska’s groundwater and surface water belong to all the people of the state. Water is a finite resource, and irrigating and fertilizer are expensive. However, good health for everyone is priceless.
LLNRD provides the following nitrate facts:
• The statewide median nitrate level in Nebraska doubled between 1978 and 2019.
• The Nebraska Water Center has stated that approximately one-third of nitrogen applied to corn in Nebraska is lost to leaching.
• Overapplication of commercial and organic fertilizer puts our water, and the health of our residents, at risk.
• Over-irrigation wastes our precious water resources, contaminates streams and groundwater, and puts the health of residents at risk.
• Nebraska has one of the highest nitrate levels in the US, and the highest pediatric cancer rate west of Pennsylvania.
• High nitrate exposure is also linked to brain cancer, colorectal cancer, thyroid cancer, leukemia, and lymphoma.
• Pregnant women should not drink high nitrate water.
• The Environmental Protection Agency’s (EPA) maximum contaminant level for nitrates in drinking water is 10 parts per million (ppm).
• Approximately 10% of Nebraska’s community water systems have exceeded the EPA’s maximum contaminant level for nitrates at least one time since 2010.
• A University of Nebraska Medical Center expert has stated that the EPA’s maximum contaminant level of 10 ppm is too high.
• Sandy, irrigated soils are highly susceptible to nitrate leaching.
• Center pivot irrigation is much more efficient than gravity irrigation, and far less likely to cause nutrients to leach into water resources.
• Buffer strips can reduce polluted runoff from reaching waterways. Cost-share is available.
• Algal blooms that impact recreation and starve lakes and fish of oxygen are fueled by nutrients including nitrates.
• “Doing things how we’ve always done them,” is not necessarily the right, safe, or responsible way of doing things today.
• Animals are also susceptible to nitrate exposure. In cattle and dogs this exposure can lead to the loss of young and reduced milk production. Hogs exposed to high nitrate water can lose entire litters.
• More is not better. The technology exists for the precise application of fertilizer, other agricultural chemicals, and irrigation water. Considering the known health effects of nitrate exposure, is there a reason to ever apply more than the crop can use?
• Landowners, land managers, farmers, ranchers, feedlot owners, homeowners, business owners, and land users must practice appropriate nutrient management and work to decrease nitrate loss.
