U.S. EPA Contaminated Site Cleanup Information (CLU-IN)

U.S. Environmental Protection Agency
U.S. EPA Technology Innovation and Field Services Division

For more information on Perchlorate, please contact:

Cynthia Frickle
Technology Assessment Branch

PH: 202-566-0927 | Email:



Perchlorate is a naturally occurring and man-made anion commonly associated with the solid salts of ammonium, potassium, and sodium perchlorate. These salts are highly soluble in water, and because perchlorate sorbs poorly to mineral surfaces and organic material, it can be very mobile in surface and subsurface aqueous systems (1). Also, because it is relatively inert under typical groundwater and surface water conditions, perchlorate contamination may persist for extended periods of time. Widespread perchlorate contamination in the United States was observed after the spring of 1997 when an analytical method was developed with a quantitation level of 4 ppb. Since then, detection of the contaminant in soil, surface water, and/or drinking water wells has been reported in 49 states, the District of Columbia. and Puerto Rico (2).

Production of ammonium perchlorate first began in the United States in the mid-1940s. Today, ammonium perchlorate and the other perchlorate salts are used in a wide range of applications, including pyrotechnics and fireworks, blasting agents, matches, lubricating oils, textile dye fixing, nuclear reactors, electronic tubes, tanning and finishing leather, rubber manufacturing, electroplating, aluminum refinishing, automobile air bag inflators, paint and enamel production, and pharmaceuticals (3). The most common use for ammonium perchlorate is in explosives and rocket propellant. Because it has a limited shelf life, the ammonium perchlorate used in the nation's rocket and missile supply must occasionally be replaced. As a result, large amounts of the compound are periodically disposed of (4).

Perchlorate is of concern for the following reasons:

  1. it has potential human health effects at low concentrations;
  2. it may be widespread in the environment;
  3. removing it from water and soil may be costly; and
  4. it may have deleterious effects on ecosystems.

In 1998, EPA placed perchlorate on its Contaminant Candidate List for possible regulation, and in 1999, EPA required drinking water monitoring for perchlorate under the Unregulated Contaminant Monitoring Rule. In February 2005, EPA established an official reference dose (RfD) of 0.0007 milligrams of perchlorate per kilogram of body weight per day. The RfD is a scientific estimate of a daily exposure level that is not expected to cause adverse health effects in humans. EPA's new RfD translates to a Drinking Water Equivalent Level (DWEL) of 24.5 ppb. A DWEL assessment assumes that all of a contaminant comes from drinking water, and it gives the concentration of a contaminant in drinking water that will have no adverse effect. A DWEL has a margin of safety, so that exposures above it are not necessarily considered unsafe. (5).

Adobe PDF LogoGroundwater Information Sheet: Perchlorate
California State Water Resources Control Board, 11 pp, 2010.

This brief groundwater information sheet provides general information (fate and transport, health effects, testing and remediation methods) and identifies where high levels of the compound are found in California. The information is pulled from a variety of sources, and a bibliography is provided.

Perchlorate: Environmental Problems and Solutions
K. Sellers, K. Weeks, W.R. Alsop, S.R. Clough, M. Hoyt, B. Pugh, and J. Robb.
Taylor & Francis/CRC Press, Boca Raton, FL. ISBN: 0849380812, 226 pp, 2006

Adobe PDF LogoPerchlorate: Overview of Issues, Status, and Remedial Options
The Interstate Technology & Regulatory Council (ITRC) Perchlorate Team, Washington, DC.
PERCHLORATE-1, 152 pp, 2005.

This overview provides basic information regarding perchlorate and perchlorate contamination. Because the information on perchlorate is continually being updated, the goal of this report is simply to provide a snapshot in time of information and issues concerning perchlorate sources, use, and occurrence; sampling and analysis; toxicity, exposure, and risk; risk management and regulatory status; and remediation.

Technical Fact Sheet - Perchlorate
U.S. EPA, Federal Facilities Restoration and Reuse Office
EPA 505-F-17-003, 9 pp, 2017.

This fact sheet, developed by the U.S. EPA Federal Facilities Restoration and Reuse Office (FFRRO), provides a brief summary of the emerging contaminant perchlorate, including physical and chemical properties; environmental and health impacts; existing federal and state guidelines; detection and treatment methods; and additional sources of information. Perchlorate is a persistent contaminant of concern that has presented a number of issues to the government, the private sector, and other organizations and interested parties. These issues include health effects and risk, regulatory standards and cleanup levels, degradation processes, and treatment technologies. This fact sheet provides basic information on perchlorate to site managers and other field personnel who are addressing perchlorate contamination at cleanup sites or in drinking water supplies.

1. Adobe PDF LogoAssessing the outlook for perchlorate remediation.
Bruce E. Logan
Environmental Science and Technology 35 (2001): 482A - 487A.

2. Adobe PDF LogoKnown Perchlorate Releases in the U.S. - March 25, 2005

3. A Systematic Approach to In Situ Bioremediation in Groundwater
Interstate Technology Regulatory Council, 2002.

4. Technology Status Report, Perchlorate Treatment Technologies. 1st ed.
Roote, Diane S.
Ground-Water Remediation Technologies Analysis Center, 2001.

5. EPA Sets Reference Dose for Perchlorate
U.S. EPA press release, 18 Feb 2005.