Groundwater Corrosivity and Lead in Private Wells

Corrosive groundwater can cause lead to leach from pipes, plumbing fixtures, and solder that contain lead into the public drinking water supply.[1] Similarly, lead also poses a threat to private well users because the Safe Drinking Water Act (SDWA) does not mandate the monitoring of the drinking water quality produced by private wells. Learn more about corrosive groundwater and what to do when private well owners find lead in their drinking water.

Lead Is of Concern for Human Health

Lead is a highly toxic metal. Multiple uses of lead increase the potential for human exposure and harm to human health.[2] No safe levels of lead exposure for children have been identified. Even at low exposure levels, children can show neurodevelopmental deficits.[3] Therefore, it is important to test for lead in drinking water systems that are not covered by the SDWA.

Environmental health specialist taking a sample for water quality determination.

Environmental health specialist taking a sample for water quality determination. Photo used by permission of the Cerro Gordo County Department of Public Health

Forms of Lead That Can Be Found in Drinking Water

Soluble and particulate lead have been found in drinking water.

  • Soluble lead is approximately between 0.1 to 0.2 micrometers in diameter and is invisible to the naked eye.
  • Particulate lead is easy to miss with standard sampling protocols. High flow rate, hydraulic disturbances, and certain materials (especially brass) help in releasing particulate lead. Particulates trapped in the aerators of water taps are visible to the naked eye and have tested positive for lead.

What to Do if Lead is in Private Well Water

In the United States, most health departments have jurisdiction over private wells and are the first responders when issues of drinking water quality emerge in those systems.

First, confirm whether lead is in the water.

  • Take a tap water sample using the approved sampling protocol in your state. Use the Environmental Protection Agency’s (EPA) protocol pdf icon[PDF – 581 KB]external icon if your state does not have one.
  • Test the sample for lead. Take or send the sample to a certified laboratory.external icon Testing is the only way to confirm if lead has leached into the system’s drinking water. It is important to identify all potential sources of lead in private well systems. If lead is found in the water, environmental health practitioners can inform the public about taking one or more of the following actions to reduce the amount of lead and minimize their potential for exposure:
  • Reduce or eliminate exposure to water contaminated by lead by using only tap water that has been run through a point-of-use filter.external icon
  • Flush water for 1-2 minutes prior to first use for drinking or cooking to reduce potential exposure to lead from household lead plumbing.
  • Drink or use only bottled water that has been certified by an independent testing organization.external icon This may not be the most cost-effective option for long-term use.

Visit the How to Reduce or Eliminate Exposure to Lead in Tap Water section on the CDC’s Lead in Drinking Water webpage for details about these actions. If there are children in the house and there are concerns about exposures to lead, ask the parents or an adult to contact the children’s doctor. The doctor may recommend the appropriate actions to follow, including a blood test to know if the children have been poisoned by lead.[4]

Additional Steps Environmental Health Practitioners Can Take

Environmental health practitioners can also work to control lead’s mobility and stop it from leaching by

  • Determining the groundwater quality of local aquifers.
  • Conducting a thorough inspection of the entire private well system and identifying sources of lead.
  • Establishing methods for sampling and identification of the lead source(s).
  • Identifying and contacting certified laboratories that can test lead in water samples.
  • Knowing the analytical methods used by the certified laboratories and the cost per test.
  • Providing technical support to help private well owners interpret test results and remedy lead problems.

Some Examples That Make Testing for Lead in Water from Private Wells Important

Corrosive groundwater can damage the pumps of wells and cause lead to leach into water.[5]

EPA found that lead was an issue in rural drinking water quality.[6]

A survey conducted in Pennsylvania to learn the water quality conditions of individual water supplies found that corrosive groundwater and leaded plumbing components contributed to leaching lead into water.[7,8]

In rural Wisconsin, results of a testing program to determine drinking water quality included lead among the contaminants detected at unsafe levels for human consumption.[9]

Researchers from Virginia Tech studying groundwater corrosivity and lead leaching identified factors that may cause the leaching of the metal into the water of private wells.[10-12]

References

[1] Centers for Disease Control and Prevention. Lead in drinking water. Available from URL: https://www.cdc.gov/nceh/lead/prevention/sources/water.htm [accessed 2019 Nov 22].

[2] Agency for Toxic Substances and Disease Registry (ATSDR). Toxicological profile for lead. U.S. Department of Health and Human Services, Public Health Service. August 2007, p. 1-6.

[3] Bellinger DC. Very low lead exposures and children’s neurodevelopment. Curr Opin Pediatr. 2008;20(2):172-7.

[4] Centers for Disease Control and Prevention. Blood lead levels in children. Available from URL: https://www.cdc.gov/nceh/lead/prevention/blood-lead-levels.htm [accessed 2020 Jan 22]

[5] Kelly GJ. Groundwater corrosion in Queensland. In: Proceedings of the 37th Conference of the Queensland Society of Sugar Cane Technology. Bundaberg, Queensland, Australia: Queensland Society of Sugar Cane Technology; 1970. p. 23-34.

[6] Francis JD, Brower BL, Graham WF, Larson OW III, McCaull JL, Moran Vigorita H. Executive summary. In: National Statistical Assessment of Rural Water Conditions. Ithaca, New York: Cornell University Department of Rural Sociology; 1982. p. 1-21.

[7] Swistock BR, Sharpe WE, Robillard PB. A survey of lead, nitrate, and radon contamination of private individual water systems in Pennsylvania. J Environ Health. 1993;55(5):6-12.

[8] Swistock BR, Clemens S, Sharpe WE, Rummel S. Water quality and management of private drinking water wells in Pennsylvania. J Environ Health. 2013;75(6):60-6.

[9] Knobeloch L, Gorski P, Christenson M, Anderson H. Private drinking water quality in rural Wisconsin. J Environ Health. 2013;75(7):16-20.

[10] Pieper KJ, Krometis L-AH, Gallagher DL, Benham B, Edwards M. Incidence of waterborne lead in private drinking water systems in Virginia. J Water Health. 2015;13(3):897-908.

[11] Pieper KJ, Krometis L-AH, Gallagher DL, Benham BL, Edwards M. Profiling private water systems to identify patterns of waterborne lead exposure. Environ Sci Technol. 2015;49(21):12697-704.

[12] Pieper KJ, Krometis L-AH, Benham BL, Gallagher DL. Simultaneous influence of geology and system design on drinking water quality in private systems. J Environ Health. 2016;79(2):E1-E9.