mil United States	°JTnZ
Environmental Protection
Agency	December 2016
Fact Sheet: Effluent Limitations
Guidelines and Standards for Dental
Offices
Summary
EPA finalized technology-based pretreatment
standards under the Clean Water Act to reduce
discharges of mercury and other metals from dental
offices into municipal sewage treatment plants
known as publically owned treatment works
(POTWs). Dental offices, which discharge mercury
and other metals present in amalgam used for
fillings, are the main source of mercury discharges to
POTWs; these metals are subsequently released to
the environment. The rule requires dental offices to
comply with requirements based on practices
recommended by the American Dental Association,
including the use of amalgam separators. Once
captured by the separator, dental amalgam can be
recycled. Removing mercury when it is concentrated
and easy to manage, such as through low-cost
amalgam separators at dental offices (average
annual cost per dental office is about $800), is a
common sense solution to managing mercury that
would otherwise be released to air, land, and water.
In addition, this rule minimizes dental office
reporting requirements and the administrative
burden to federal, state, and local regulatory
authorities responsible for oversight of the new
requirements.
EPA expects compliance with this final rule will
reduce the discharge of metals to POTWs by at least
10.2 tons per year, about half of which is mercury.
EPA projects the total annual cost of the final rule
will be $59 - $61 million.
Background
Why are standards needed for the dental industry?
When dentists remove old amalgam fillings from
cavities, or when dentists place a new filling,
mercury in the form of dental amalgam enters the
wastewater of the dental office. Mercury from waste
amalgam can make its way into the environment
from the POTW through the incineration, landfilling,
or land application of sludge or through surface
water discharge. Mercury is a potent neurotoxin that
can have a wide range of health effects, and mercury
pollution is a global concern. Once released into the
aquatic environment, certain bacteria can change
mercury into methylmercury, a highly toxic form of
mercury that bioaccumulates in fish and shellfish.
Eating fish and shellfish is the main source of
people's exposure to methylmercury in the U.S.
Who is affected by this regulation?
This rule applies to offices, including large
institutions such as dental schools and clinics, where
dentistry is practiced that discharge to a POTW. It
does not apply to mobile units or offices where the
practice of dentistry consists only of the following
dental specialties: oral pathology, oral and
maxillofacial radiology, oral and maxillofacial
surgery, orthodontics, periodontics, or
prosthodontics.

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Control Authorities (which are often the state or
POTW) are responsible for oversight associated with
this rule.
What does this rule require of dental
offices?
Dental offices that discharge to POTWs that do not
place or remove amalgam need only submit a one-
time certification.
Dental offices that place or remove amalgam must
operate and maintain an amalgam separator and
must not discharge scrap amalgam or use certain
kinds of line cleaners. They must also submit a One-
Time Compliance Report.
Where can I find more information?
You can access the Federal Register notice on EPA's
Effluent Guidelines website at:
www.epa.gov/eg/dental-effluent-guidelines. In
addition, the final rule will be available at
regulations.gov under Docket ID: EPA-HQ-OW-2014-
0693.
You may also email Karen Milam at
milam.karen@epa.gov.

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