National Drinking Water Database
Heptachlor in Delaware
Heptachlor is a highly toxic and carcinogenic termiticide banned from most applications in the U.S. since 1988. [read more]
Heptachlor is one of 12 highly toxic, persistent organic pollutants (POP), called the "dirty dozen," that are scheduled for global phase-out under the international POP treaty (Stockholm Convention on persistent organic pollutants (POPs) 2009).
Heptachlor had been used in the past as a non-agricultural insecticide/termiticide in homes and buildings, and on food crops. Due to concerns about its toxicity and persistence, heptachlor has not been used for these purposes since 1988. The only permitted commercial use of heptachlor products is for fire ant control in buried electric power transformers, and in underground cable television and telephone cable boxes (U.S. Environmental Protection Agency (USEPA) 2009b).
Heptachlor is highly toxic to humans and can be absorbed through the skin, lungs and gastrointestinal tract. It also causes severe toxicity of the central nervous system with symptoms such as lethargy, dizziness, labored respiration, muscle tremors and convulsions (Agency for Toxic Substances and Disease Registry (ATSDR) 1993a). Longer-term exposure to heptachlor may lead to damage to the liver, kidney, spleen, thyroid and cause cataracts and cancer. EPA classifies heptachlor and heptachlor epoxide as probable human carcinogens (Hazardous Substances Data Bank (HSDB) 2001a; USEPA 2009b).
In the environment, heptachlor breaks down into heptachlor epoxide. Both heptachlor and heptachlor epoxide are stored in fat and can be taken up into the food chain by plants and bioconcentrate into fish, animals and milk. Heptachlor had been released directly to the soil in connection with its past use in termite and fire ant control. Heptachlor has been also found in wastewater and emissions from some industrial facilities, especially solvent recovery operations.
The Most Polluted Communities in Delaware
2 water utilities reported detecting Heptachlor in tap water since 2004, according to EWG's analysis of water quality data supplied by state water agencies
Ranked by highest average Heptachlor level
|Rank||System||Population Served||Positive test results of total reported tests||Average Level|
|60||1 of 4||0.02 ppb|
(0 to 0.07 ppb)
|2||Artesian Water Company|
|201,000||1 of 83||< 0.01 ppb|
(0 to 0.01 ppb)
Health Based Limits for Heptachlor
|Maximum Contaminant Limit Goal (MCLG)||A non-enforceable health goal that is set at a level at which no known or anticipated adverse effect on the health of persons occurs and which allows an adequate margin of safety. Source: U.S. Environmental Protection Agency.||0 ppb|
|EPA Human Health Water Quality Criteria||Water quality criteria set by the US EPA provide guidance for states and tribes authorized to establish water quality standards under the Clean Water Act (CWA) to protect human health. These are non-enforceable standards based upon exposure by both drinking water and the contribution of water contamination to other consumed foods. Source: U.S. Environmental Protection Agency.||<0.01 ppb|
|California Public Health Goals||Defined by the State of California Office of Environmental Health Hazard Assessment (OEHHA) as the level of contaminant that is allowed in drinking water. For acutely toxic substances, levels are set at which scientific evidence indicates that no known or anticipated adverse effects on health will occur, plus an adequate margin-of safety. PHGs for carcinogens or other substances which can cause chronic disease shall be based solely on health effects without regard to cost impacts and shall be set at levels which OEHHA has determined do not pose any significant risk to health.||<0.01 ppb|
|One in one million (10-6) Cancer Risk||The concentration of a chemical in drinking water corresponding to an excess estimated lifetime cancer risk of 1 in 1,000,000. Source: U.S. Environmental Protection Agency.||<0.01 ppb|
|Maximum Contaminant Limit (MCL)||The enforceable standard which defines the highest level of a contaminant that is allowed in drinking water. MCLs are set as close to health-based limits (Maximum Contaminant Level Goals, or MCLGs) as feasible using the best available analytical and treatment technologies and taking cost into consideration. Source: U.S. Environmental Protection Agency.||0.4 ppb|
|One in ten thousand (10-4) Cancer Risk||The concentration of a chemical in drinking water corresponding to an excess estimated lifetime cancer risk of 1 in 10,000. Source: U.S. Environmental Protection Agency.||0.8 ppb|
|Children's health-based limit for 1-day exposure||Concentration of a chemical in drinking water that is not expected to cause any adverse, noncarcinogenic health effects for up to one day of exposure. The One-Day health-based limit (or Health Advisory, HA) is typically set to protect a 10-kg child consuming 1 liter of water per day. Source: U.S. Environmental Protection Agency.||10 ppb|
|Children's health-based limit for 10-day exposure||Concentration of a chemical in drinking water that is not expected to cause any adverse, noncarcinogenic effects for up to ten days of exposure. The Ten-Day health-based limit (or Health Advisory, HA) is typically set to protect a 10-kg child consuming 1 liter of water per day. Source: U.S. Environmental Protection Agency.||10 ppb|
|Drinking Water Equivalent Level||A lifetime exposure concentration protective of adverse, noncarcinogenic health effects, that assumes all of the exposure to a contaminant is from drinking water. Source: U.S. Environmental Protection Agency.||20 ppb|
Violation Summary for Heptachlor in Delaware
There are no violations reported for this contaminant in Delaware