Mercury in dental wastewater originates from waste particles associated with the placement and removal of amalgam fillings. Dental amalgam is used to restore teeth in dental practices. It is an alloy that contains mercury (approximately 50%) bound together with other metals. EPA estimates there are approximately 160,000 dentists working in over 120,000 dental offices who use or remove amalgam in the United States - almost all of whom discharge their wastewater exclusively to Publicly Owned Treatment Works (POTWs).
The goal of the Dental Amalgam Discharge Reduction Program is to ensure all dental offices comply with the followings requirements:
- Installation of amalgam separator (filtration system to reduce the amount of mercury solids passing into the sewer system).
- Proper maintenance of such separators, including documentation and maintenance logs.
- Implementation of adequate best management practices, such as recycling of all amalgam waste collected in dental offices.