Alternative causes of wide-spread, low concentration perchlorate impacts to groundwater

Abstract

The frequency of detection of perchlorate in groundwater and drinking water supplies has been steadily increasing since its initial identification as a chemical of concern in 1997. It is currently estimated that perchlorate is present in groundwater in at least 30 states and affects the drinking water supplies of more than 20 million people in the southwestern United States (U.S.). The source of perchlorate in water supplies has typically been attributed to U.S. Department of Defense (DOD), National Aeronautics and Space Administration (NASA) and/or defense contractor facilities that have used ammonium perchlorate (AP) in rocket and missile propellants. As a result of its high profile and its addition to the Unregulated Contaminant Monitoring Rule (UCMR List I), which requires perchlorate analysis by large public water suppliers and selected small water utilities, most public water supplies are now being routinely analyzed for perchlorate. Through monitoring activities, perchlorate has been detected at low levels (typically less than 50 μg/L) in a significant number of areas without apparent military sources. While natural sources or formation mechanisms for perchlorate may explain its presence in some cases,1,2 widespread, low concentration perchlorate impacts in groundwater can apparently also result from a variety of nonmilitary- based inputs as well, potentially including: i) storage, handling and use of Chilean nitrate-based fertilizers containing perchlorate; ii) manufacturing, storage, handling, use and/or disposal of fireworks containing perchlorate; iii) manufacturing, storage, handling, use and/or disposal of road flares containing perchlorate; iv) manufacturing, storage, handling, use and/or disposal of explosives or pyrotechnics containing perchlorate; and/or v) manufacture, storage, handling and use of electrochemicallyprepared (ECP) chlorine products, primarily those that contain chlorate or were manufactured from chlorate feedstocks. The potential impacts of these non-military perchlorate products and processes on the environment are discussed in the following sections. © 2006 Springer Science+Business Media, Inc.