United States Environmental Protection Agency Office of Water Office of Pesticides and Toxic Substances Fall 1990 &ER& National Pesticide Survey ,2-Dibromo-3-Chloropropane (DBCP) H H H I I I H-C—C-C-H I I I Br Br a 1,2-Oibromo-3-Chloroprop«n« (DBCP) What Is DBCP? How Does DBCP Behave in So// and Ground Water? How Do** DBCP Get Into Ground Water? The U.S. Environmental Protection Agency (EPA) has completed its five-year National Survey of Pesticides in Drinking Water Wells (NPS), a study of the presence of 127 pesticides, pesticide degradates, and nitrate in community water system (CWS) wells and rural domestic drinking water wells. l,2-dibromo-3-chloropropane (OBCP) was detected in the Survey. This fact sheet provides a description of OBCP, its potential health effects, and guidance on both treating and preventing well contamination. l,2-dibromo-3-chtoropropane is known by the common names dibromochloro- propane and DBCP. DBCP was registered for use in the late 1940s. DBCP was used as a soil fumigara for nematode control prior to its cancellation in the United States. Commercial names for DBCP included Nemafume, Nemanax, Nemaset, Nematocide, BBC 12, Fumazone, Nemagon, and Oxy DBCP. The behavior of a pesticide after it is released to the environment is dependent upon its movement in air, water, and soil as well as the rate at which it is transformed, or broken down. Pesticides applied to crops or the soil surface may volatilize (vaporize) to the atmosphere, be carried off by surface runoff, be carried to ground water through leaching, or remain in the soil through adsorption (adherence) to soil particles and undergo Uttle movement in air or water. Pesticides may be transformed by reaction with water, microorganisms, and exposure to sunlight The likelihood that DBCP wi migrate into ground water is influenced by its tendency to be transported (move) from soil to air and water and to be transformed by these various processes. as wet ee by the characteristics of the sfte, such as soil type, moisture, temperature. and depth to ground water. DBCP has a high potential to be transported, and a low- to-medium potential to be transformed. DBCP migration into ground water could result from Its underground injection as a soil fumigant for agricultural applications. DBCP could also reach ground water from direct entry into a wen through accidental chemical spite or improper storage near a well. WPS f ,2-0ibromo-3-CMoropropcfw (DBCP) ------- Findings of the National Pesticide Survey What Hea/t/t Effects Might be Caused by DBCP in Drinking Water? How is Water Treated to Remove Contami- nants? How Can Water Contamina- tion be Prevented? Based on the results of the NPS, EPA estimates that DBCP is present, at or above the analytical detection level of 0.010 pg/L used in the Survey, in about 370 (0.4%) CWS wells and 38.400 (0.4%) rural domestic wells nationwide. Considering the precision of the Survey, EPA estimates that the number of CWS wells with detectable levels of DBCP could be as low as 33 or as high as 1,480, and the number of rural domestic wells could be as low as 2,740 or as high as 164,000. DBCP is measured in micrograms per liter (yg/L) which is equivalent to parts per billion (ppb). In rural domestic wells DBCP was detected at concentrations above the proposed Maximum Contaminant Level (MCL) of 0.2 mg/L EPA notified wells owners and operators within 24 hours when detections exceeded health-based guidelines or standards. Non-Cancer Effects: A Lifetime Health Advisory Level for DBCP in drinking water has not been established by EPA. Consuming DBCP, however, has been shown to result in adverse health effects in animal studies, including decreased sperm production and damage to the kidneys, liver, and testes. CWSs are required to notify customers if the drinking water that they deliver contains contamination that exceed the MCL Cancer R/*Jr: DBCP causes cancer in laboratory animals that are given high doses of the pesticide over the course of their lifetimes. Therefore, EPA considers DBCP to be a probable human carcinogen (cancer-causing agent). EPA estimates that if an individual consumes water containing DBCP at 0.03 jjg/L over his or her entire lifetime, that person would theoretically have no more than a one-in-a-miilion chance of developing cancer as a direct result of drinking water containing this pesticide. Standard: EPA sets enforceable standards for public water systems, called MCLs. These, regulatory standards set achievable levels of drinking water quality to protect human health. The proposed MCL for DBCP is 0.2 fjg/L (proposed as of May 22, 1989). DBCP can be detected in drinking water by a laboratory using an EPA method such as #504. If DBCP is detected in well water and confirmed by retesting to be above 0.03 pg/L, State or County health officials should be consulted. They may advise periodic retesting to get an accurate overall picture of the water quality because changes in seasonal precipitation and changes in pesticide use can cause variations in the amount of chemicals found in water wells. They also may advise using an alternative drinking water supply (bottled water is an example of a temporary alternative), treating the water, or drilling a new or deeper well. Public water suppliers are required to notify customers if the drinking water that they deliver contains a contaminant that exceeds its MCL You may also be able to treat your well water to remove pesticides and other contaminants. Treatment technologies that can remove DBCP from water include aeration and carbon adsorption. However, these techniques are not necessarily appropriate or avaflabte in every situation. Certain treatment methods are more suitable for large community water systems than for individual domestic wells. State or County heaftti officiate should be able to provide advice on the best approach to foflow. Several steps may be taken to prevent pesticides or nitrate from entering wells, such as eliminating direct entry through the well wall, drilling a new wed, or modifying or reducing pesticide and fertilizer use. E//m/nate O/rect Entry Through tne Will Will If pesticides or nitrate are present in well water, they may be entering the ground water through the weir itself rather than through the soil. If the well is old or Doorty constructed, or if there are visible cracks in the well casing, obtain expert NPS (DBCP) ------- Why was the National Pesticide Survey Conducted? Where to Go for More Information advice on whether or not improvements can be made to the well. In addition, investigate simple methods of capping the well or sealing it at the surface to prevent entry. Do not conduct any mixing activities near the well if you use well water to mix pesticides because a spill could lead to direct contamination of the well. Drill a fVtw wall If the soil surrounding the well is the source of contamination, drilling a new or deeper well may make sense if water can be drawn from a deeper, uncontaminated aquifer. Unfortunately, it often is difficult to know the quality of the ground water without drilling or extensive testing. Seek expert advice before you drill. Learn More about Patticida t/te if you use pesticides, whether for agricultural or home lawn and garden purposes, you should consider attending training courses given by your State or County agriculture department on how to reduce activities that can contaminate ground water. You may find that you can eliminate or lessen the frequency or quantity of your pesticide usage by choosing alternative methods of pest control. EPA conducted this Survey to determine the frequency and concentration of pesticides, pesticide degradates, and nitrate in drinking water wells nationwide and to examine the relationship between the presence of pesticides in drinking water wells and patterns of pesticide use and ground-water vulnerability. The Survey sampled 566 community water system wells and 783 rural domestic wells for 127 pesticides, pesticide degradates, and nitrate. The wells were selected as a representative statistical sample to provide nationwide estimates of the presence of pesticides and nitrate in drinking water wells, and are not meant to provide an assessment of pesticide contamination at the local, County, or State level. This fact sheet is part of a series of NPS outreach materials, fact sheets and reports. The following additional fact sheets are available through EPA's Public Information Center (401 M Street SW, Washington, DC 20460. (202) 382-2080): Survey Datlgn Survey Anatytat Quality Assurance/ Quality Control Analytical Method* Summary Raaulta Fact Sfteef tor each detected anatyta Pro/ect Summary Glossary How EPA Will Uaa The NPS Raaulta Additional information on the Survey and on pesticides in general can be obtained from the following sources: U.S. EPA Safe Drinking Water Hotline 1-80CM26-4791 On Washington, DC (202) 382-5533) Monday-Friday, 8:30 am to 4:30 pm Eastern Time National Pesticide Telecornmunications Network 1-800-858-7378 24 hours a day U.S. EPA Office of Pesticide Programs (OPP) Docket Public Information Branch (H7506C) 401 M Street, SW Washington/ DC 20460 Telephone: (703) 557-2805 Information on regulation of pesticides in drinking water Information on health effects and safe handling of pesticides Background documents for Survey (available for review) NPS f ,2-Dfbromo^CMoropropMW (DBCP) ------- National Technical Information Service (NTIS) Copies of the 5285 Port RoyaJ Road NPS Phase I Report Springfield, VA 22161 (available 1991) (703) 487-4650 and NPS Phase II Report (when available) If you are concerned about the presence of pesticides and nitrate in your private water well, contact your local or State health department Other experts in your State environmental agency or agriculture and health departments may also be helpful to you. If you receive your drinking water from a community water system and have questions about your water quality, contact your local community water system owner/operator or the State water supply agency. « Bibliography Meister Publications. Farm Chemicals Handbook. Ohio: Meister Publications, 1990. U.S. Environmental Protection Agency. Drinking Water Health Advisory: Pesticides. Michigan: Lewis Publishers, 1989. U.S. Environmental Protection Agency. Drinking Water Regulations and Health Advisories. April, 1990. U.S. Environmental Protection Agency. Health Advisory Summaries. January 1989. U.S. Environmental Protection Agency. Pesticides in Drinking Water Wells. September 1989. MPS t.2-Oftroflio-3-CWoreprep«n« (06CP) ------- |