Dental Category 

Outreach and Data 

Collection 

Public Docket for the Effluent Limitation Guidelines and Standards for the 

Dental Category

EPA Docket Number EPA-HQ-OW-2014-0693 (www.regulations.gov)

23 September 2014
Dental Category Outreach and Data Collection

I. Overview

Across the United States, many states and publicly owned treatment works 

(POTWs) are working to reduce discharges of mercury to POTWs. EPA is proposing 

regulations for the dental industry that include pretreatment standards for the control of 

mercury in wastewater. EPA is proposing technology-based pretreatment standards under 

the Clean Water Act (CWA) for discharges of pollutants into POTWs from existing and 

new dental offices1that discharge dental amalgam. The proposed rule would require 

dental offices to control the discharge of mercury and other metals in dental amalgam 

into POTWs based on the best available technology or best available demonstrated 

control technology (amalgam separators) and the use of best management practices 

(BMPs). The BMPs are (1) eliminating the flushing of scrap amalgam down drains and 

(2) cleaning chair-side traps with non-bleach, non-chlorine cleaners. EPA is also 

proposing to amend selected parts of the General Pretreatment Regulations (40 CFR 403) 

to streamline oversight requirements for the Dental Category. 

EPA first identified the dental industry for study in its review of the health 

services industry in the 2006 Effluent Guidelines Plan (71 FR 76644). EPA selected the 

industry based in part on public comments about discharges of mercury from dental 

offices and dental laboratories. The Health Services Industry Detailed Study Report for 

Dental Amalgam (EPA-821-R-08-014) was completed in August 2008 (U.S. EPA, 2008). 

EPA collected data from a variety of sources for the proposed Dental Amalgam 

Rule, including the Health Services Industry Detailed Study, stakeholder discussions with 

organizations such as the Environmental Council of the States and the American Dental 

Association (ADA), amalgam separator manufacturer contacts, and journal publications 

and studies on the use of amalgam separator systems. EPA used data from these sources 

to develop a profile of the industry, describe dental mercury sources and waste 

characteristics, describe the environmental impacts of mercury, identify state and local 

programs to reduce mercury discharges from dental offices, characterize the effectiveness 

and costs of amalgam separators and BMPs, and develop pollutant discharge loadings 

estimates with and without control technologies. 

II. Comments Received on the Preliminary 2008 Effluent Guidelines Plan that 

Focus on the Dental Industry 

EPA published its Preliminary 2008 Effluent Guidelines Plan on October 30, 

2007 (72 FR 61335). The plan included a summary of EPA’s detailed study for the health 

services industry, including mercury discharges from the dental industry. Most of the 

comments received were from pretreatment programs that provided useful information on 

their mandatory and voluntary programs that include the use of amalgam separators. EPA 

used this information to update its Health Services Industry Detailed Study Report for 

Dental Amalgam (EPA-821-R-08-014). Table 2, at the end of this document, includes a 

 

1 This document uses the general term “offices” to refer to any dentistry practice or facility that places or 

removes dental amalgam containing mercury.
Dental Category Outreach and Data Collection

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list of the comments received on the Preliminary 2008 Effluent Guidelines Program Plan

for the dental industry.

III. Outreach and Data Collection Activities 

The outreach and data collection goals for the Health Services Industry Detailed 

Study and Proposed Effluent Limitation Guidelines and Standards (ELGs) for the Dental 

Category included: (1) establish points of contact between the EPA and dental industry 

associations, POTW associations, vendors, and other stakeholders; (2) further EPA’s 

understanding of the dental industry, including amalgam management and disposal; (3) 

identify outreach opportunities to association members and other interested stakeholders; 

(4) provide transparency on EPA’s actions and decision-making; (5) identify and resolve 

issues as early as possible; and (6) identify treatment technologies and BMPs for mercury 

in amalgam. EPA’s outreach and data collection activities helped EPA to address the 

following questions: 

 What are the current industry practices for disposing of dental amalgam 

(containing mercury and other metals), to what extent are each of these 

practices applied, and what factors affect the use of these practices? 

 What are the federal, state, or local requirements or guidance for disposal 

of dental amalgam? 

 How are control authorities currently limiting mercury discharges from 

dental offices? 

 Do POTWs report pass through or interference problems related to dental 

mercury discharges? 

 What technologies are available (1) as alternatives to wastewater disposal 

and (2) to control discharges? How effective are these technologies? 

 What BMPs are used as alternatives to wastewater disposal and/or to 

control discharges? How effective are these practices? 

 What are the costs of the identified technologies and/or BMPs? 

EPA’s data collection included a review of available literature on the dental 

industry and a focus on ways to reduce mercury discharges to POTWs. EPA reviewed 

literature and collected data on the dental industry, amalgam separators, and mercury 

discharges, including:

 Current, relevant technical publications that describe the sources and 

generation of mercury wastes at dental offices and the discharge of mercury 

and other amalgam filling metals (i.e., copper, silver, tin, and zinc) to POTWs.
Dental Category Outreach and Data Collection

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 Current information on possible treatment solutions (i.e., amalgam separators) 

for dental offices to reduce mercury in the wastewater and their effectiveness.

 Current implementation costs for technologies to reduce mercury and other 

metal discharges at dental offices.

Some of the key references that EPA used as part of the development of the proposed rule 

are listed in Table 1.

Table 1. Key References

Author Title Year

Document 

Control Number

ADA Best Management Practices for Amalgam 

Waste

2007 DA00165

ADA ADA Professional Product Review 2007 DA00043

ADA ADA Distribution of Dentists in the United 

States by Region and State, 2008

2010 DA00123

ADA 2009 Survey of Dental Practice: Income from 

the Private Practice of Dentistry

2010 DA00141

Batchu, H., D. 

Rakowski, P.L.Fan, 

and D.M. Meyer

Evaluating Amalgam Separators Using an 

International Standard, Journal of the 

American Medical Association, 137:999-1005

2006 DA00183

Batchu, H., H.N. 

Chou, D. Rakowski, 

and P.L. Fan

The Effect of Disinfectants and Line Cleaners 

on the Release of Mercury from Amalgam, 

Journal of the American Dental Association 

137(10):1419-1425

2006 DA00215

Beazoglou T, Brown 

LJ, Ray S, Chen L, 

Lazar V

An Economic Study of Expanded Duties of 

Dental Auxiliaries in Colorado, Dental Health 

Policy Analysis Series, American Dental 

Association

2009 DA00149

Cain, A. and R. 

Krauel, U.S. EPA and 

Environment Canada

Options for Dental Mercury Reduction 

Programs: Information for State/Provincial 

and Local Governments. 

2003 DA00003

Condrin, A.K. The Use of CDA Best Management Practices 

and Amalgam Separators to Improve the 

Management of Dental Wastewater, Journal of 

the California Dental Association 32(7):583-

592

2004 DA00024

Fan, P.L., H. Batchu, 

H.N. Chou, W. 

Gasparac, J. Sandrik, 

and D.M. Meyer

Laboratory Evaluation of Amalgam 

Separators. Journal of the American Medical 

Association, 133:577-584

2002 DA00008

Georgetown 

University

Safety Net Dental Clinic Manual, National 

Maternal & Child Oral Health Resource 

Center

2003 DA00143

International 

Organization for 

Standardization

ISO 11143: 2008 Dentistry - Amalgam 

Separators Standard

2008 DA00138
Dental Category Outreach and Data Collection

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Author Title Year

Document 

Control Number

Larry Walker 

Associates

Mercury Source Control and Pollution 

Prevention Program Evaluation. Prepared for 

Association for Metropolitan Sewerage 

Agencies (AMSA)

2002 DA00006

Massachusetts Water 

Resources Authority

Amalgam Composition in Typical Dental 

Fillings

2001 DA00131

McManus, K.R., and 

P.L. Fan

Purchasing, Installing and Operating Dental 

Amalgam Separators, Journal of the American 

Dental Association, 134:1054-1065

2003 DA00162

Metropolitan Council 

Environmental 

Services (MCES)

Evaluation of Amalgam Removal Equipment 

and Dental Clinic Loadings to the Sanitary 

Sewer

2001 DA00007

MCES Revised – Features of Approved Amalgam 

Separators

2009 DA00070

Milwaukee 

Metropolitan Sewerage 

District & University 

of Wisconsin 

Extension

Amalgam Management for Dental Offices 2006 DA00232

NACWA An Examination of Mercury Levels at Clean 

Water Agencies 2003-2006

2007 DA00108

Stone, M.E. The Effect of Amalgam Separators on 

Mercury Loading to Wastewater Treatment 

Plants, Journal of the California Dental 

Association 32(7):593-600

2004 DA00018

Vandeven, J., and S. 

McGinnis

An Assessment of Mercury in the Form of 

Amalgam in Dental Wastewater in the United

States, Water, Air and Soil Pollution 164:349-

366

2005 DA00163

U.S. Air Force Synopsis of Dental Amalgam Separators 

(Project #10-017)

2011 DA00079

The outreach activities include meetings with stakeholders and discussions with 

vendors to gather specific data on the operation, maintenance, costs, and treatment 

effectiveness of amalgam separators and BMPs. Table 3 includes a summary of these 

meetings.

Meetings with Stakeholders

 Environmental Council of the States: EPA participated in several meetings with 

the Quicksilver Caucus (QSC) of the Environmental Council of the States. From 

QSC, EPA collected information on implementing mandatory amalgam separator 

programs at the state level, mandatory program language, and compliance 

reporting and monitoring. QSC also provided EPA with information on efficiency 

standards for amalgam separators (ECOS, 2010).

 Environmental Organizations: EPA met with a coalition of environmental 
Dental Category Outreach and Data Collection

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organizations, led by The Environmental Law and Policy Center and the National 

Resources Defense Council. Meetings between EPA and the coalition of 

environmental organizations focused on identifying the environmental impacts of 

dental amalgam discharges. In spring 2011, the coalition submitted a letter listing 

its suggested BMPs for the proposed Dental Amalgam Rule (Wu, 2011). 

 American Dental Association (ADA): EPA met with ADA in 2010 and 2011. 

ADA submitted data to EPA on their recently adopted principles for addressing 

mercury discharges from dental offices, the number of specialty offices in the 

industry, the geographic distribution of dental offices, financial characteristics of 

the industry, and operating characteristics of the industry (ADA, 2010).

 National Association of Clean Water Agencies (NACWA): EPA met with 

NACWA in 2010 and 2011 to discuss the impact of pretreatment standards on 

POTWs. NACWA provided EPA information on its members’ experiences with 

handling mercury wastes from dental offices, implementing pretreatment 

programs for dental offices, and implementing pretreatment standards for 

industries with similar characteristics as the dental industry. NACWA also 

provided EPA with information on the burden to permitting authorities of 

implementing a dental amalgam pretreatment standard under the existing 

requirements in Part 403 (U.S. EPA, 2011).

Amalgam Separator Manufacturers (Vendor Contacts)

EPA met with, or participated in calls with, representatives of multiple amalgam 

separator manufacturers (ERG, 2010; ERG and Air Techniques, 2011; ERG and 

American Dental Accessories, 2011; ERG and DRNA, 2011; ERG and Rebec Solutions, 

2011; ERG and SolmeteX, 2011). The purpose of the meetings was to gather information 

on the following issues:

 How amalgam separators work, limitations of the technology, and system 

capacity.

 Treatment technology effectiveness.

 Installation, operation, and maintenance requirements and equipment lifetime.

 Capital costs and operating and maintenance costs.

 Manufacturers’ distribution methods.

 Amalgam disposal.

 Installation trends.

IV. References

ADA. 2010. ADA Principles to be Used to Develop Mandatory Separator Pretreatment 

Rule. Washington, DC. October 29. Document Control Number (DCN) 

DA00137.
Dental Category Outreach and Data Collection

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ECOS. 2010. Letter to EPA: Implementing a National Vision of Mercury. Washington, 

DC. August 19. DCN DA00158.

ERG (Eastern Research Group). 2010. SolmeteX meeting minutes for 15 December 

2010. Chantilly, VA. DCN DA00081.

ERG and Air Techniques. 2011. Notes from telephone conversation between Kimberly 

Landick, ERG, and Air Techniques. March 2, 2011. Subject: Amalgam Separator 

Questions. DCN DA00060.

ERG and American Dental Accessories. 2011. Email correspondence between Kimberly 

Landick, ERG, and American Dental Accessories. February 28, 2011. Subject:

Request for Amalgam Separator Information. DCN DA00061.

ERG and DRNA (Dental Recycling North America). 2011. Notes from telephone 

conversation between Kimberly Landick, ERG, and Marc Sussman and Darwin 

Moreira, DRNA. March 1, 2011. Subject: Amalgam Separator Questions. DCN 

DA00062.

ERG and Rebec Solutions. 2011. Notes from telephone conversation between Kimberly 

Landick, ERG, and Rebec Solutions. March 2, 2011. Subject: Amalgam Separator 

Questions. DCN DA00063.

ERG and SolmeteX. 2011. Notes from telephone conversation between Kimberly 

Landick, ERG, and SolmeteX, March 2, 2011: Subject Amalgam Separator 

Questions. DCN DA00064. 

U.S. Air Force. 2011. Synopsis of Dental Amalgam Separators (Project #10-017). Dental 

Evaluation and Consultation Service. February. DCN DA00079.

U.S. EPA. 2008. Health Services Industry Detailed Study: Dental Amalgam. EPA-821-R08-014. Washington, DC. August. DCN DA00057.

U.S. EPA, 2011. Information Collection Request: National Pretreatment Program. OMB 

Control No. 2040-0009, EPA ICR No. 0002.14 (Draft). Office of Wastewater 

Management. March. DCN DA00144.

Wu, Mae. 2011. Comments from Multi-state Mercury Products Campaign, the 

Environmental Law and Policy Center, and National Resources Defense Council. 

April 1. Washington, D.C. DCN DA00136.
Dental Category Outreach and Data Collection

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Table 2. Comments Submitted on the Preliminary 2008 Effluent Guidelines Program Plan for the Dental Industry

Commenter Name Affiliation Date Posted

Preliminary 2008 Plan,

EPA Docket Number

Dental Category 

Record DCN

William J. Walsh

Pepper Hamilton LLP, on behalf of the 

American Dental Association (ADA) 2/27/2007 EPA-HQ-OW-2006-0771-0003 DA00324

William J. Walsh Pepper Hamilton LLP, on behalf of the ADA 12/28/2007 EPA-HQ-OW-2006-0771-0837 DA00238

Leo H. Hermes

Metropolitan Council Environmental Services 

(MCES) 12/7/2007 EPA-HQ-OW-2006-0771-0828 DA00321

Bruce E. Cunha Marshfield Clinic 12/13/2007 EPA-HQ-OW-2006-0771-0829 DA00322

Linda Eichmiller

Association of State and Interstate

Water Pollution Control Administrators 12/21/2007 EPA-HQ-OW-2006-0771-0834 DA00323

Christie True

County Wastewater Treatment Division 

(WTD) 1/14/2008 EPA-HQ-OW-2006-0771-0860 DA00325

Thomas P. Uva The Narragansett Bay Commission (NBC) 1/15/2008 EPA-HQ-OW-2006-0771-0861 DA00237

Janet Gillaspie

Oregon Association of Clean Water Agencies 

(ACWA) 1/2/2008 EPA-HQ-OW-2006-0771-0845 DA00240

Cynthia A. Finley

National Association of Clean Water 

Agencies (NACWA) 1/2/2008 EPA-HQ-OW-2006-0771-0849 DA00236

Beryl B. Fletcher Oregon Dental Association 1/2/2008 EPA-HQ-OW-2006-0771-0846 DA00320

Larry Lamperti City of Corvallis, Oregon (OR) 1/3/2008 EPA-HQ-OW-2006-0771-0857 DA00235

Sheila Lockwood University of Washington 1/29/2008 EPA-HQ-OW-2006-0771-1008 DA00326
Dental Category Outreach and Data Collection

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Table 3. Dental Industry Outreach and Data Collection Meetings

Title Location Date Dental Category Record DCN

Meeting with Environmental Council of States Washington, DC 2010

Follow-up Comments: DA00158

(8/19/2010)

Meeting with SolmeteX Washington, DC 12/15/2010 DA00081

Meetings with ADA Washington, DC 2010; 2011

Follow-up Comments: DA00137

(10/29/2010)

Meetings with NACWA Washington, DC 2010; 2011 Follow-up Comments: DA00144

Meeting with The Environmental Law and Policy Center 

and the National Resources Defense Council Washington, DC 2011

Follow-up Comments: DA00136

(4/1/2011)

Meeting with Dental Recycling North America, Inc. Washington, DC 1/19/2011 DA00059

Teleconference with Dental Recycling North America, Inc. Teleconference 3/1/2011 DA00062

Teleconference with Air Techniques Teleconference 3/2/2011 DA00060

Teleconference with Rebec Solutions Teleconference 3/2/2011 DA00063

Teleconference with SolmeteX Teleconference 3/2/2011 DA00064

Teleconference with SolmeteX Teleconference 5/10/2011 DA00120