Reducing nitrate intake and health complications from drinking private well water

Nitrate is a naturally occurring compound found in soil and water. However, certain human activities (e.g., fertilizing crops, livestock operations, and domestic wastewater) can contribute to concentrations of nitrate beyond the level considered safe. Consumption of high concentrations of nitratesⁱ has been linked to various negative health outcomesⁱⁱ. Those most at risk of experiencing negative health outcomes include women of childbearing age, children, infants less than 6 months old, elderly people, and animals. Living in areas with high nitrate levels may increase residents’ risk of consuming the compound. While public and community water systems have testing and treatment requirements, private wells do notⁱⁱⁱ. In Nebraska, about 20% (~400,000 people) of the total population^iv  depend upon private wells for their drinking water. Therefore, residents using private wells are the primary at-risk group of concern in this project.

The team at the Daugherty Water for Food Global Institute had conversations with numerous educators, public health experts, and natural resource managers to identify opportunities to limit nitrate consumption and associated barriers for individuals dependent on drinking water through private wells. The goal of the “Private Well Water in Nebraska” graphic is to inform private well water consumers, policymakers, and other stakeholders about the barriers to protection from potential health complications and share information on how individuals can limit their nitrate intake through drinking water.

Challenges to reducing nitrate intake and health impacts

One of the main challenges related to the prevention of nitrate intake through drinking water from private wells is a lack of awareness of nitrate exposure in drinking water and the associated health risks. Nebraska’s Natural Resources Districts (NRDs), the local governments responsible for groundwater management (including nonpoint source pollution in Nebraska), are one of the organizations addressing this issue by providing local community education. Another important factor is that the prevention of nitrate contamination may be out of the control of those who use a private well, especially if they live in the vicinity of a pollution source^v. The process of reducing the input of contaminants can be further complicated by high historical levels of nitrate in well water caused by previous owners and renters of a property.

In the case of experiencing negative health impacts of nitrate, seeking medical care can be complicated in rural areas. In Nebraska, 13 counties lack a primary care physician^vi, and specialists are densely concentrated in eastern portions of the state. Consequently, increased travel distances, times and expenses to seek medical care may be required in addition to the cost of care. Lastly, the most common water treatment option for lowering nitrate levels, reverse osmosis, can pose a higher demand for water quantity and a significant financial burden. Despite these challenges, private well users in Nebraska have opportunities to limit their exposure to nitrate via drinking water.

Opportunities to reduce exposure

While additional opportunities to limit nitrate intake through drinking water may depend on the status of land ownership and use, two generalized actions are to regularly test the well water quality and to treat water when necessary. Water sampling provides current and accurate measures of nitrate concentration and can be implemented by individuals. To promote knowledge of nitrate contamination, many NRDs provide free testing resources for residents. If high nitrate concentrations are found, households may install in-home purifying systems within points of use, like sinks. The Nebraska Department of Environment and Energy^vii may subsidize the costs of installment for qualifying residents. Meanwhile, other households may rely entirely on bottled water. Both options, however, are costly and can result in excess waste through water and plastics.

For individuals who rely on private wells, regularly testing their water quality and implementing water treatment  systems may grant users more control in ensuring safe water consumption. In the presence of barriers, various Nebraskan organizations and groups may consider investing in education on water quality, water sampling resources, financial aid for water treatment, and strengthening Nebraska’s health care accessibility. Through individual and collective efforts, the health impacts of nitrate consumption via drinking water can be mitigated and addressed.

Acknowledgements

This work was supported by the Water, Climate and Health Program, UNMC College of Public Health project, Health and Economic Impact Analysis of Nitrate Contamination of Groundwater in Nebraska, and the Daugherty Water for Food Global Institute at the University of Nebraska.

ⁱThe federal Safe Drinking Water Act (1974) set a maximum contaminant level of nitrate in drinking water to 10 milligrams of nitrate per liter.
ⁱⁱWhile the Safe Drinking Water Act was initially a response to blue baby syndrome, further studies have associated nitrate consumption below the MCL to adverse birth outcomes [1,2], increased cancer risks [3-5], and pregnancy complications [6,7].

[1] Brender, J.D.; Weyer, P.J.; Romitti, P.A.;Mohanty, B.P.; Shinde, M.U.; Vuong, A.M. (2013).Prenatal nitrate intake from drinking water and selected birth defects in offspring of participants in the national birth defects prevention study.Environ. Health Perspect. 121, 1083–1089.
[2] Bukowski, J.S.; Bryanton, J. (2001). Agricultural contamination of groundwater as a possible risk factor for growth restriction or prematurity. J. Occup. Environ. Med. 43, 377–383.
[3] Espejo, H.N.; Gracia, L.E.; Boldo, E.; Aragones, N.; Perez-Gomez, B.; Pollan, M. (2016).Colorectal Cancer risk and Nitrate exposure through drinking water and diet. Int. J. Cancer. 139, 334–346.
[4] Ward, M.M.; Cantor, K.P.; Weisenburger, D.D.; Correa-Villaseñor, A.; Zahm, S.H. (1996). Drinking water nitrate and the risk of non-Hodgkin’s lymphoma. Epidemiology. 7, 465–471.
[5] Weyer, P.J.; Cerhan, J.R.; Kross, B.C.; Hallberg, G.R.; Kantamneni, J.; Breuer, G.; Jones, M.P.; Zheng,W.; Lynch, C.F. (2001).Municipal Drinking Water Nitrate Level and Cancer Risk in Older Women: TheIowa Women’s Health Study. Epidemiology. 11, 327–338.
[6] Manassaram, D.M.; Backer, L.C.; Moll, D.M. (2005).A Review of Nitrates in Drinking Water: Maternal Exposure and Adverse Reproductive and Developmental Outcomes.Environ. Health Perspect. 114, 320–327.
[7] Tabacova, S.B.; Little, R.E. (1997). Maternal exposure to exogenous nitrogen compounds and complications of pregnancy. Arch. Environ. Health 52, 341–347.

ⁱⁱⁱOffice of the Federal Register, National Archives and Records Administration. (1974, December 19). 88 Stat. 1660 - Safe Drinking Water Act. [Government]. U.S. Government Publishing Office. https://www.govinfo.gov/app/details/STATUTE-88/STATUTE-88-Pg1660-2
^ivNebraska’s Public Water System Program 2022 Annual Report, available here: http://dee.ne.gov/NDEQProg.nsf/OnWeb/PWS.
^vFor township-level distribution of median (2000-2019) Nitrate-N concentration, see Figure 14 in 2022 Groundwater Quality Monitoring Report, available: http://deq.ne.gov/Publica.nsf/PubsForm.xsp?documentId=3C9B46502ED96C8E8625890B007127DB&action=openDocument.
^viWehbi NK, Mosalpuria K, Deras M, Palm D, Wilson FA, Carritt N. The Status of the Nebraska Healthcare Workforce: 2020 Update. Omaha, NE: UNMC Center for Health Policy; 2020.
^viiPrivate well reverse osmosis system rebates are available to property owners of private wells with drinking water test levels above 10 milligrams of nitrate per liter; available at: http://dee.ne.gov/Press.nsf/pages/PR010423.