What exactly are nitrates?
Nitrates, which is a form of nitrogen, are plant nutrients needed for improved growth, but excess of these nutrients can cause adverse impacts on human health.
When too much nitrogen or fertilizer is applied, plants cannot absorb the nitrates quickly enough. It soaks down through the vadose zone or the unsaturated zone of the soil, and continues down to the water table, or the saturated zone. From this point, nitrates can enter natural bodies of water and wells.
Where do nitrates come from?
Nitrogen and nitrates can enter the environment in a variety of ways. While nitrogen is a necessary part of plant growth and occurs naturally, excess nitrogen is usually caused by human activity.
- Over-application of fertilizers can cause nitrogen runoff, as well as the infiltration of nitrates into the water table.
- Nitrate can be formed in water bodies through the oxidation of other forms of nitrogen, including nitrite, ammonia, and organic nitrogen compounds such as amino acids.
- Ammonia and organic nitrogen can enter water through sewage runoff from land where manure has been applied or stored.
- Nitrogen is also released when crops are harvested, where it reenters the atmosphere as a gas.
- Over 3 million tons of nitrogen from fossil fuels are deposited in the United States annually from the atmosphere.
What are the effects of nitrates?
Nitrates are a compound that cannot be seen or smelled, but can have profound impacts on people, land, and wildlife. Nitrates can be harmful to wildlife and livestock, causing illness if levels are too high. Bodies of water can also be negatively affected by high nitrate levels; water which has high levels of nitrates can see harmful algal blooms, which is when a high concentration of algae consumes the oxygen in a body of water, which in turn suffocates fish and other plant life.
Humans can also be impacted by the negative effects of nitrates. According to the CDC, drinking water with high levels of nitrate can be harmful, specifically to women and infants. Early studies conducted by the University of Nebraska Medical Center, show a correlation between high chemical content (including nitrogen) and pediatric cancer rates. High nitrate levels have also been linked to methemoglobinemia, or blue baby syndrome. Blue baby syndrome causes low oxygen levels in the blood and causes infants skin to turn blue. After a rise in cases, the Environmental Protection Agency (EPA) put a nitrate-level restrictions of 10 mg/L (10 parts per million or ppm). If a well or water system tests with nitrate levels over this amount, state and local officials are required to take action to remedy the situation.
Nebraska’s Nitrate Problem
Nebraska has some of the highest risk in the country for groundwater contamination. This is due to several contributing factors including: high nitrogen inputs, irrigated crops, shallow depths to groundwater, and sandy soils.
These factors pose serious risk to Nebraska’s water systems, including the Ogallala Aquifer, also known as the High Plains Aquifer. The High Plains Aquifer is a source of groundwater that spans eight states and it covers 2/3 of Nebraska. This groundwater is a major source of drinking and irrigation water for the state.
Rural Nebraskans and Nitrates
Rural Nebraskans are especially vulnerable to nitrates. 88% of Nebraskans rely on the Aquifer for their groundwater, and nearly 100% of rural Nebraskans drink groundwater and/or utilize private wells. In 2017, 349 locations across the state, or about 1.4 million people (about 3/4 of the state’s population), had nitrate levels above background.
Once a drinking water source is discovered to have contaminants, it can be treated via distillation, reverse osmosis, and ion exchange. However, these methods can be expensive, and many communities rely on loans from the state or federal government to build water meters, filtration systems, or new wells. Small towns and villages are hit with huge bills for nitrate treatment, often collectively in the millions. Communities are then required to pay for upkeep of the system, which is typically funded through a rise in water bills.
Nearly 33,000 Nebraskans are affected by groundwater contamination. Roughly 350 to 400 of the state’s 600 community drinking water systems have safeguards for E. Coli and other bacteria, but not nitrates. The high reliance on groundwater in rural areas, combined with the lack of funding for nitrate filtration and treatment, leaves many small towns without proper nitrate management.
Current Action
With Nebraska being at such high risk for nitrate contamination, what is being done? Agriculture’s large role in the Nebraska economy, especially in the economy of rural towns, makes it difficult to imagine forgoing traditional practices. The current goal is to mitigate and manage nitrate outputs, while also not damaging the livelihoods of communities that rely on agriculture.
Currently, community water systems work together with the state and the EPA to ensure safe and clean drinking water for residents. The Safe Drinking Water Act passed in 1974 and protects both surface and groundwater from nitrate contamination, as well as mitigating current contamination.
Nebraska has a process it uses to address the rising level of nitrates in public water systems. If a community’s water system tests with a level above 5 ppm, it is put on watch and requires quarterly testing. 99/550 Nebraska public water systems require quarterly nitrate testing. Once a community tests consistently under 8 ppm, it is released from the testing program. If it goes above this threshold, it requires permanent water monitoring and testing. If a community tests above 10.5 ppm, then the system will receive a violation notice. Two of these violation notices in 3 quarters, and they would receive an administrative order. Currently, 4 Nebraska public water systems have received administrative orders, with several townships even breaching 20 ppm.
In addition to state and federal government action, Nebraska’s Natural Resource Districts, or NRDs, take action locally for their districts. These NRDs work with the state and its organizations to establish wellhead protection areas and create Integrated Management Plans, or IMPs, which work to solve specific watershed issues holistically, addressing both surface and groundwater bodies. Water quality issues, like nitrate contamination, are issues that the NRDs can oversee, and many have implemented regulations on the community and producers.
Nebraska farmers and ranchers are also working to reduce their output of nitrogen. Farmers work with NRDs to utilize best management practices (BMPs) on their land, taking part in test programs, using less fertilizer, and even using technology to monitor and report soil quality, runoff, and water quality. Some farmers are even switching to organic crops, ditching synthetic fertilizers all together. According to the USDA, organic farming operations in Nebraska increased by 74% – from 159 to 277 between 2012 and 2017.
Nebraskans are working towards a safer and healthier environment. Increased education on the effects of nitrates and their sources has led to increased action against nitrate contamination. However, many are still unaware of the contents of their water, and in some areas of the state, nitrate levels are still increasing. The problem of nitrate contamination is a problem that will take time, cooperation, and determination to solve.
Testing Your Water
One of the best ways to advocate for water protection is to educate yourself and others through water testing. Testing your water is easier than it might sound, and is a task which can not only help keep your family safe, but can also protect your community. Twice per year, the Citizen Science Program allows for a sign-up to receive water testing kits, which include test strips, instructions, a return envelope, and information on how to log your test results. This not only aids you in knowing more about your water, but also helps officials paint a picture of water quality throughout Nebraska.
Other Resources
Want to learn more about nitrates in Nebraska? Here are some great resources that will help you learn more!
- Nitrates in Nebraska – A site compiling information specifically about Nebraska’s nitrate issues as they relate to agriculture, community, and economy.
- UNL’s Water Program – A general education site with resources and articles written by specialists in the field.
- The USGS Water Science School – An educational resource with information ranging to the basics of water quality, to complex hydrological issues.
- The Drinking Water Extension – Another resource compiled by specialists in the field.
Sources
Drinking Water Extension. (23 Aug 2019) “Drinking Water Contaminant – Nitrate.”
EPA. (15 Feb 2022) “Overview of the Safe Drinking Water Act.” EPA.
Nebraska WAVES. (10 March 2022) “Nebraska’s Nitrate Challenge.” Nebraska WAVES.
Powers, C., and Pekarek, K. (13 Aug 2021) “Nebraska Nitrate Working Groups –
Summary and Call for Action.” UNL Water.
Powers, C., Walsh, J.F., and Pekarek, K. (4 Sept 2020) “Nitrate in Nebraska.” UNL Water.
USDA. (n.d.) “Irrigation & Water Use.” USDA.
USGS. (2015) “Predicted concentrations of nitrate in U.S. groundwater.” USGS.
