Arsenic
Chromium VI Dense Nonaqueous Phase Liquids (DNAPLs) 1,4-Dioxane Dioxins Mercury MTBE Perchlorate POPs PCBs TCE Other Contaminants Overview 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:
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). Emerging Contaminant - Perchlorate This fact sheet provides a brief summary for 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 a cleanup site or in a drinking water supply. Perchlorate: Environmental Problems and Solutions Perchlorate: Overview of Issues, Status, and Remedial Options 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. 1. Assessing the outlook for perchlorate remediation. 2. Perchlorate: Summary of DoD Sampling by State and Installation
3. A Systematic Approach to In Situ Bioremediation in Groundwater 4. Technology Status Report, Perchlorate Treatment Technologies. 1st ed. 5. EPA Sets Reference Dose for Perchlorate |