Heptachlor epoxide adsorbs strongly to soil, but is extremely resistant to biodegration, persisting for many years in the upper soil layers. Similarly in water, heptachlor epoxide will persist, usually in sediments. It is concentrated extensively in aquatic life. It is taken up into the food chain into animals and milk.
A federal law called the Emergency Planning and Community Right to Know Act (EPCRA) requires facilities in certain industries, which manufacture, process, or use significant amounts of toxic chemicals, to report annually on their releases of these chemicals. For more information on the uses and releases of chemicals in your state, contact the Community Right-to-Know Hotline: (800) 424-9346.