&EPA
United States
Environmental Protection
Agency
Office of Water EPA- 821-F-14-002
www.epa.qov
September 2014
Effluent Limitation Guidelines and Standards for the
Dental Category
Summary
EPA is proposing technology-based
pretreatment standards under the Clean Water
Act for discharges of pollutants into publicly
owned treatment works (POTWs) from existing
and new dental practices that involve the
discharge of dental amalgam. The proposal
would require dental practices to comply with
requirements for controlling the discharge of
dental amalgam pollutants into POTWs based on
the best available technology or best available
control technology and Best Management
Practices.
EPA is also proposing to amend selected parts of
the General Pretreatment Regulations (40 CFR
Part 403) to streamline oversight requirements
for the dental sector. EPA expects compliance
with this proposed rule would reduce the
discharge of metals to POTWs by at least 8.8
tons per year, half of which is mercury. EPA
estimates the annual cost of the proposed rule
would be $44 to $49 million.
Why is EPA proposing this rule?
When dentists remove old amalgam fillings
from cavities, or when dentists place a new
filling, mercury in the form of dental amalgam
enters the waste water of the dental office.
Studies have shown that dental offices are the
largest source of mercury discharges to POTWs,
contributing about half of the mercury received
by POTWs. Mercury is a persistent and
bioaccumulative pollutant with well-documented
effects on human health. When in water, certain
microorganisms can change mercury into
methylmercury, a highly toxic form that builds
up in fish, shellfish and animals that eat fish.
Fish and shellfish are the main sources of
methylmercury exposure to humans.
The proposed rule would require all affected
dentists to control mercury discharges to
POTWs by reducing their discharge of dental
amalgam to a level achievable through the use of
the best available technology (amalgam
separators) and the use of Best Management
Practices. In order to simplify compliance with,
and enforcement of the numeric reduction
requirements, the proposed rule would allow
dentists to demonstrate compliance by installing,
operating and maintaining amalgam separators.
The proposal also includes a provision by which
dental offices that have already installed
amalgam separators that do not meet the
proposed amalgam removal efficiency would
still be considered in compliance with the rule
for the life of the amalgam separator. Removing
concentrated sources of mercury to POTWs
opportunistically, such as through low-cost
amalgam separators at dental offices (average
annual cost per dental office: $700), is a
common sense solution to managing mercury
that would otherwise be released to air, land, and
water.
Proposed Pretreatment Standards for the
Dental Category Include:
• Technology-based pretreatment standards for
discharges of pollutants into POTWs from
existing and new dental practices that involve
the discharge of dental amalgam
• Dental offices covered by this proposed rule
could control mercury discharges to POTWs
by reducing their discharge of dental
amalgam to a level achievable through the
use of the best available technology
(amalgam separators) and the use of Best
Management Practices.
• Amendments to selected parts of the General
Pretreatment Regulations (40 CFR Part 403)
to streamline oversight requirements for the
dental sector and to eliminate discharge
monitoring for the dentists.
-------
For More Information
You can view the Federal Register Notice at
http://www.epa.gov/guide/dental. In addition,
the proposed rule will be available at
http://www.regulations.gov under Docket ID:
EPA-HQ-OW-2014-0693. Upon Federal
Register publication, EPA will accept public
comments on this proposed rule for 60 days.
You may also contact Damon Highsmith at
Highsmith.Damon@epa.gov.
------- |