COMMENTS OF THE AMERICAN DENTAL ASSOCIATION 

CONCERNING THE ENVIRONMENTAL PROTECTION 

AGENCY DENTAL OFFICE SCOPING STUDY
 TABLE OF CONTENTS 

I. INTRODUCTION................................................................................................................. 1

II. A VOLUNTARY AMALGAM SEPARATOR PROGRAM WILL BE EFFECTIVE, 

AVOID WASTEFUL TRANSACTION COSTS, AND IS MORE APPROPRIATE TO 

ATTAIN MERCURY REDUCTION FROM A PROFESSIONAL GROUP, SUCH AS 

DENTISTS............................................................................................................................. 2

A. Introduction......................................................................................................................... 2 

B. The ADA Proposal for Voluntary Separators..................................................................... 2 

C. The Nature of the Dental Community ................................................................................ 4 

D. The Dental Community Has Already Taken Significant Steps .......................................... 5 

E. Public-Private Partnerships with ADA Have Worked In The Past..................................... 6 

F. Voluntary Amalgam Separator Programs --- Success Stories ............................................ 7 

G. EPA Policy Favoring Voluntary Approaches................................................................... 10 

H. Conclusion ........................................................................................................................ 10 

III. THE BENEFIT OF VOLUNTARY SEPARATORS VERSUS MANDATORY 

SEPARATORS.................................................................................................................... 11

A. Introduction....................................................................................................................... 11 

B. Amalgam Use Has Decreased........................................................................................... 11 

C. Amalgam Is a De Minimis Contributor to Releases to the Environment ......................... 12 

D. Incremental Collection of Amalgam................................................................................. 13 

1. The Conceptual Model ............................................................................................... 13 

2. Corrections to the EPA Analysis............................................................................... 14 

a. Introduction............................................................................................................. 14 

b. The Size of Particles Entering the Separator in a Dental Office ........................ 14 

c. The Percent Capture by Treatment Plants .......................................................... 15 

d. Percentage of Separators in a Voluntary Program ............................................. 17 

e. The Effectiveness of Separators............................................................................. 19 

3. The Incremental Difference in Amalgam Collected ................................................ 19 

E. Disposal of Collected Amalgam ....................................................................................... 22 

F. Defining the Benefit/Effectiveness of Separators by the Amount of Amalgam Collected

 23 

G. Conclusion ........................................................................................................................ 27 

IV. COSTS AND COST-EFFECTIVENESS.......................................................................... 27

V. CONCLUSION ................................................................................................................... 31
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I. INTRODUCTION

The following are the American Dental Association’s (“ADA”)1 comments on the 

Environmental Protection Agency’s (“EPA”) preliminary study of the need for a pretreatment 

rule requiring mandatory use of amalgam separators by dental offices to reduce the discharge of 

amalgam into sewerage treatment systems (“mandatory amalgam separators”) or, in the 

alternative, achieving the same goal through implementation of the ADA voluntary Best 

Management Practices for Amalgam Wastes (2007) (“ADA 2007 BMPs”), which includes the 

voluntary use of amalgam separators. The ADA strongly supports reliance on the on-going 

implementation of the ADA 2007 BMPs and, for several reasons that are discussed in these 

Comments, believes that mandatory amalgam separators would be unreasonable and impractical. 

Section II summarizes the ADA approach, already underway, and explains why a 

voluntary program is both effective and preferable for professionals such as dentists, particularly 

given that amalgam wastewater is only responsible for a small fraction of the total mercury that 

enters surface waters each year. 

Section III describes the benefits of these two options. The benefit of each 

alternative must be compared to baseline conditions, which includes a growing number of states 

and localities (see Attachment 3) that already have either mandatory or voluntary separator 

programs. 

Section IV explains the reasons that a mandatory separator requirement would be 

inconsistent with current law and policy and is not cost-effective. 

Much of EPA’s analysis is sound, but in several instances either more information 

is needed or an assumption needs to be updated.2

 Rather than repeat information already in the 

record from the ADA’s prior submissions, this Comment focuses on the few areas where there 

may be disagreements between the ADA and EPA. 
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II. A VOLUNTARY AMALGAM SEPARATOR PROGRAM WILL BE EFFECTIVE, 

AVOID WASTEFUL TRANSACTION COSTS, AND IS MORE APPROPRIATE 

TO ATTAIN MERCURY REDUCTION FROM A PROFESSIONAL GROUP, 

SUCH AS DENTISTS 

A. Introduction

EPA is considering the use of a pretreatment rule to require mandatory installation 

of amalgam separators in all dental offices that place amalgam restorations. ADA has issued 

revised BMPs for amalgam wastes that, among other things, recommend the use of amalgam 

separators (i.e., a voluntary professional standard of practice). 

Subsection (B), below, describes the ADA proposed voluntary separator 

approach. Section (C) explains why the dental community would be an ideal candidate for a 

voluntary mercury reduction program. Subsection (D) summarizes the steps already taken by the 

dental community. Subsection (E) provides an example of a successful public-private 

partnership with ADA. Subsection (F) provides some examples of successful, voluntary, 

amalgam separator programs. Subsection (G) discusses EPA’s policy favoring voluntary 

approaches. Subsection (H) discusses the increased transaction costs and legal hurdles of using a 

mandatory versus a voluntary program. 

B. The ADA Proposal for Voluntary Separators

The ADA urges EPA to implement its desired goal (i.e., the reduction of mercury 

discharges from sewerage treatment plants into surface water) through a voluntary program to 

prmote the implementation of ADA’s BMPs. 

First, the goal of this program would be to convince the dentists in the US to 

adopt the 2007 ADA BMP (which includes use of amalgam separators). Thus, the goal of a 

voluntary and mandatory separator program is essentially the same. 
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Second, the ADA will use the considerable resources at its disposal (discussed 

below), in conjunction (we hope) with the EPA, state, and local governments, to educate the 

dental community on the merits of using separators and to take action (where possible with 

amalgam manufacturers and similar stakeholders) to eliminate institutional, conceptual or 

economic barriers to the use of amalgam separators. 

Third, tools exist to monitor the progress of a voluntary separator program. For 

example, the ADA (and, as appropriate, State and local dental associations) could work with 

EPA, state regulators, and municipalities to track the use of amalgam separators and the amount 

of amalgam collected and recycled. In addition, the amalgam separator manufacturers (which 

recycle amalgam) and any non-separator amalgam recyclers are also equipped to monitor a 

voluntary program. The ADA would be willing to consider supplementing this tracking 

information, if needed, (as well as re-enforcing its message to dentists to install amalgam 

separators) by surveying the ADA membership on the degree of amalgam use and other 

amalgam waste disposal practices.3

 

Fourth, the type of program that is most likely to be successful is one that imposes 

the least transaction costs on both the dental community and the sewerage treatment agencies. 

For example, it would be unproductive and cost-ineffective to require permits or monitoring of 

dental office discharges. 

Fifth, a voluntary amalgam separator program avoids the inequities and 

inefficiencies caused by the use of a rigid, command and control, “one-size fits all” approach that 

requires the mandatory use of separators (typically within a very short time frame) even in 

locations where the methylmercury levels in fish are well below EPA’s 0.3 ppm limit4

 and in 
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areas where 99.9% of the methylmercury is likely to be attributable to air emissions or the 

residue from historic mining activities (see Section III).5

 

Sixth, implementation of the BMPs could be enhanced through guidance issued 

by the Office of Pretreatment, which provides direction to EPA Regional Offices, States, and 

municipalities. 

Seventh, since this offer seems to have been misunderstood by some in the past, 

we reiterate (hopefully clearly) that a voluntary partnership with the ADA would not bar EPA 

from making a determination in the future that use of mandatory separators is necessary to fulfill 

EPA’s statutory mandate. Similarly, the ADA understands that an EPA decision not to issue a 

pretreatment rule does not bar States from taking action pursuant to state law or policies. 

However, the current situation provides both EPA and the ADA with an ideal opportunity to 

jointly promote good amalgam waste management practices and ensure that virtually all of the 

amalgam waste is recycled. 

Finally, the ADA’s voluntary, best management approach would result in 

installation of separators even in areas where the methylmercury levels in fish and mercury 

concentrations in biosolids are below regulatory limits. In other words, the dental community is 

prepared to embrace a sustainable (action beyond compliance) approach to increase recycling of 

amalgam. 

C. The Nature of the Dental Community

The dental community consists of highly educated professionals. Virtually all 

dentists are small business owners who value both their independence and their profession – 

improving the public’s dental health. 

As with most professionals, indeed more so, dentists rely upon their professional 

associations – the ADA at the national level, the state dental association at the state level, and the 
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local dental association in their own community – for information and assistance in solving 

problems and addressing issues that arise in the operation of their business.6

 Nationally, the 

ADA is a trusted source of information to its 155,000 member dentists. The ADA is also widely 

recognized as a source of reliable information by the public (e.g. its Seal of Acceptance program 

for consumer dental products) and by non members. The ADA has the capacity, and utilizes it, 

to regularly communicate with every dentist in the nation, both ADA members and non 

members. 

Environmental issues have only become significant to the dental community since 

the late 1990s. At that time, most dentists were unfamiliar with the environmental jargon, 

overarching regulatory schemes, and the direct command and control approach that are common 

in the interaction between the regulators and regulated. This regulatory scheme (which is 

familiar to most in industry) was and, to some extent, remains less familiar to dentists than other 

aspects of their professional life. 

In the ADA’s opinion, one of the lessons learned from some of the early, less 

successful interactions between sewerage treatment plant officials and the dental community is 

that any program (voluntary or mandatory) should take into account the nature of the dental 

community. The ADA is uniquely suited to help in this endeavor. 

D. The Dental Community Has Already Taken Significant Steps

The ADA has: (1) initiated an amalgam national advocacy initiative to alert the 

dental community about the issues and to offer a positive solution, with similar efforts at state 

and local levels;7

 (2) issued the 2003 ADA BMPs which recommended collection of 81% of the 

amalgam discharges, recycling of that amalgam, and ending the use of bulk amalgam; (3) met 

repeatedly with EPA and state regulators (commenting on guidance and proposing partnerships); 

(4) tested the effectiveness of separators in collecting amalgam prior to the discharges to sewers; 
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(5) provided information on the cost of separators and a practical guide for dentists wishing to 

select separators (this ongoing effort was just recently updated8

); (6) implemented a long-term 

dental amalgam wastewater education program (i.e., seminars, training sessions, and other 

outreach events); (7) performed research on the effectiveness of separators in reducing 

discharges of mercury to surface water;9

 (8) successfully worked with other stakeholders, 

including EPA, to adopt an American National Standards Institute (“ANSI”) voluntary standard 

for dental amalgam recycling, storage, and management;10 (9) in October 2007 revised the ADA 

BMPs to include amalgam separators; and (10) has led research on developing and implementing 

nonamalgam material for use in dental restorations.11 Further, the ADA is in constant 

communication with its members through its web site (www.ADA.org), the ADA News (which 

is also sent several times per year to every dentist in the nation (approximately 175,000 dentists), 

not just ADA members), the Journal of the American Dental Association (a peer-reviewed 

journal) and similar vehicles. The ADA is also actively exploring feasible methods of 

eliminating barriers to the purchase of separators and assisting dentists to purchase separators 

voluntarily and recycle amalgam as cost-effectively as possible. A number of state dental 

societies have done so as well. 

In short, the dental community is a cohesive network of professionals who are 

ready, willing, and able to cooperate with EPA to ensure that a voluntary mercury reduction 

program is a success. 

E. Public-Private Partnerships with ADA Have Worked In The Past

The ADA has partnered with federal regulatory agencies in the past to much 

success.12 For example, in April 2004, the Occupational Safety and Health Administration 

(OSHA) and the ADA formed an Alliance (which was renewed on May 18, 2006) through which 

OSHA and ADA agreed to “provide ADA members and others with information, guidance, and 
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access to training resources that will help them protect employees’ health and safety, particularly 

in reducing and preventing exposure to ergonomic hazards.”13 

The Alliance has succeeded in educating dentists concerning OSHA standards 

through outreach by ADA and OSHA- or ADA-developed materials, training programs, 

workshops, seminars, and lectures. Specifically, the ADA and OSHA have worked together to 

develop a Hand Pain Tip Sheet for Dentists, and is working on additional Alliance-related 

projects. The ADA reaches out to U.S. dentists regarding these efforts in a variety of ways, 

including use of ADA’s website.14 

Other examples of effective public-private partnerships include the Dry Cleaning 

Work Group, the development of a regulatory guidebook by National Association of 

Homebuilders and the Occupational Safety and Health Administration, and voluntary amalgam 

reduction efforts like the Pueblo Dental Mercury P2 project.15 

F. Voluntary Amalgam Separator Programs --- Success Stories 

Partnerships between the state or local dental association and state environmental 

agency have been effective in promoting voluntary compliance. One source estimates that 65% 

of dentists involved in voluntary programs will install separators, based on a range of 

participation rates from 38% to 100%.16 The States of Minnesota, Washington, and 

Massachusetts created voluntary programs that have worked to promote amalgam separator use. 

The Minnesota Dental Association (MDA) and the Metropolitan Council of 

Environmental Services (MCES) launched the Voluntary Dental Office Amalgam Separator 

Program in 2001. According to the MDA, 85% of eligible dentists in the state (dentists not 

exempt under a voluntary program) have committed to installing amalgam separators. Seventytwo percent of these committed dentists have already installed a separator or are exempt.17 
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In Washington, a Memorandum of Understanding (MOU) was signed by the 

Washington State Dental Association and the Washington Department of Ecology in August 

2003. The MOU advocated and supported BMPs, which included installation of amalgam 

separators. In August 2004, at the end of the first year of the MOU period, a survey reported that 

34% of dentists installed separators.18 One year later in August 2005, another survey reported 

that 80% of dentists had installed separators.19 The survey also indicated that another 16% of 

dentists committed to installing separators by November 2005, bringing separator compliance up 

to 96%.20 The Department of Ecology’s compliance inspectors also contacted 441 dentists and 

found only 31, or 7%, who had not installed separators.21

In 2004, the Massachusetts Department of Environmental Protection (MA DEP) 

worked with the Massachusetts Dental Society to establish a voluntary program for dentists to 

install amalgam separators.22 The plan called for 50% of Massachusetts Dental Society’s 

member dentists to participate by January 2005, 90% by January 2006, and 100% by January 

2007, with regulations to follow if these goals are not met. Due to the cooperation of the 

Massachusetts Dental Society, the program was extremely successful and by April 2005, the MA 

DEP reported that 75% of dentists installed separators, vastly exceeding the goals of the first 

year.23 In April 2006, MA DEP promulgated regulations mandating that all dental facilities 

install separators, but those dentists who complied with the voluntary program were rewarded 

with an exemption from the regulation (i.e. record keeping and reporting) until 2007, or 2010, 

depending on how early the dentist complied. 

Voluntary programs have also been used successfully at various stages in Wichita, 

Kansas; Duluth, Minnesota; Minneapolis/St. Paul, Minnesota; Madison, Wisconsin; Palo Alto, 

California; and the East Bay Municipal Utility District (“EBMUD”). 
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In April 2000, the City of Wichita, Kansas initiated a Mercury Code of 

Management Practices (CMP). Phase 1 was an effort to encourage voluntary use of technologies 

beyond the chair side trap and vacuum filter, e.g., a separator. Phase 2 of the program would 

have required mandatory separators if it had been needed, but the implementation of the 

mandatory approach was contingent on the success of the voluntary effort. In fact, because 

“60% of dental community voluntarily complied with program initially,” the City decided not to 

implement Phase 2. 24 Currently, without a mandatory separator requirement, “98% of the 200 

dental offices in the City have complied with the Mercury CMP Program. . . . The cooperation of 

the dental community ... contributed to this enormously successful program, and will set a 

standard for other cities.”25 

In 1992, the Western Lake Superior Sanitary District (“WLSSD,” i.e., Duluth) 

and the Northeast District Dental Society former a public-private partnership that provided 

education on how to recycle amalgam waste, trained all dental offices, made presentations at 

local dental society meetings, and prepared written materials.26 As an incentive, the WLSSD 

purchased and installed separators, but the largest long-term cost (recycling the amalgam) is 

borne by the dentists. Duluth phased its installation of separators from 2001 to 2003 (by which 

time 51 of 52 separators were installed).27 Factors contributing to the success of the program 

included the leadership of the local dental society, peer-to-peer interaction with area dentists, 

including explaining the need to properly manage amalgam waste to prevent mercury from 

entering the environment and demonstrating the proper methods for doing so, financial 

incentives to install amalgam separators, and a discount waste disposal option through WLSSD’s 

“Clean Shop” Program. 
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In 2003, the Metropolitan Council of Environmental Services (MCES) and the 

Minnesota Dental Association (MDA) launched a program to identify Minneapolis and St. Paul 

dental clinics that used amalgam to encourage them to install separators. 700 clinics in the Twin 

Cities metropolitan area participated in the program. To date, more than 99% of the clinics 

eligible for the program have installed separators.28

Thus, state and local voluntary separator programs have been successful in many 

(although not all) municipalities. The key for a successful effort is developing a cooperative 

relationship with the dental associations, rather than an adversarial approach. 

G. EPA Policy Favoring Voluntary Approaches

EPA Office of Pretreatment’s overall policy is to “encourage and reward 

voluntary reductions.”29 In 2003, EPA was confronted with a similar situation and proposed to 

use a Pollution Prevention (P2) Alternative to a pretreatment rule for the Metal Products and 

Machinery Point Source Category. This rule provided “voluntary incentive[s] for ... indirect 

dischargers that agreed to perform specific best management/pollution prevention practices.”30

In the past, the EPA Office of Wetlands, Oceans, and Watersheds has published 

guidance favoring the use of BMPs to implement applicable water quality standards.31 For 

example, in 1997, EPA published a technical support document for the Voluntary Advanced 

Technology Incentives Program, which sought to encourage paper mills to make substantial 

environmental progress beyond the base level compelled by law.32

H. Conclusion

The ADA will continue its efforts to implement its BMPs and would working 

with EPA to implement a nationwide voluntary separator program. The long-term goals of both 

EPA and the ADA are the same – to promote the use of amalgam separators. Even in the shortand medium-term, there is little incremental difference in the amount of amalgam collected and 
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recycled using a voluntary separator program compared to a mandatory plan (see Section III (D) 

below). Thus, a voluntary program would be just as effective as a mandatory approach. Indeed, 

such a voluntary program, backed by the ADA and (we would hope) by EPA would provide a 

consistent and more credible joint message and magnify the resources available. 

This sort of voluntary program has demonstrably worked in many states and 

localities and the ADA has been involved in other successful voluntary compliance programs. In 

fact, EPA policy strongly favors a voluntary program, especially when small businesses are 

involved. A voluntary program is also more cost-effective and would avoid wasteful transaction 

costs involved in enforcing regulations. 

Finally, EPA has little to lose by working with the ADA on a voluntary approach 

first. If a voluntary effort turns out to be ineffective, then nothing would preclude EPA from 

promulgating additional, even mandatory, requirements. Thus, mandatory requirements should 

not be the initial approach. 

III. THE BENEFIT OF VOLUNTARY SEPARATORS VERSUS MANDATORY 

SEPARATORS 

A. Introduction

The heart of the decision facing EPA is whether the benefits of using a mandatory 

versus voluntary separator program is worth the costs – particularly given the demonstrable and 

similar environmental benefits achievable through use of a voluntary approach. 

B. Amalgam Use Has Decreased

This submission includes new data on the continued decrease in the use of 

amalgam. Amalgam use has declined to one third of the 1979 level and 20.5% below the 1999 

level (which was the basis of the 2005 Vandeven and McGinnis analysis). 

The trend is as follows: 
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1979: 157 million restorations used dental amalgam.33

1990: 96 million restorations used dental amalgam out of 200 million (48%).34

1999: 66 million restorations utilized amalgam.35 

2005: 52.5 million (31.6% of all restorations) utilized amalgam.36 

It is projected that there will be approximately 46.7 million amalgam restorations 

in 2008 (only 20.5% of all dental restorations) based on past trends.37 

In summary, the amount of amalgam used has dramatically decreased over the 

last several decades and continues to decline.38 This decline should be taken into account in the 

assessment of the fate of dental amalgam. 

C. Amalgam Is a De Minimis Contributor to Releases to the Environment

The concern about mercury in the US is based, almost exclusively, on the concern 

about the levels of methylmercury in fish. Neither the Clean Water Act nor any other statute 

gives EPA the legal authority to limit, no less ban, the discharge of mercury into sewerage 

treatment plants, if: (1) the methylmercury concentration in fish does not exceed the EPA water 

quality standard of 0.3 ppm or the total mercury concentration in biosolids does not exceed the 

biosolids limits (57 ppm, or 17 ppm for exceptional quality biosolids) or (2) if the mercury 

discharge to the treatment plant does not cause the exceedance of these limits.39 

The vast majority of mercury that is causing methylmercury concentration in fish 

to exceed the water quality standard of 0.3 ppm is from air deposition or unique local sources, 

not amalgam.40 The United States’ official position is that when the dominant sources of 

mercury are “not sources that can be regulated under” the Clean Water Act (e.g., from air 

emissions or historic mining sources), the fact that a water quality standard is not met “does not 

represent a ‘violation of the CWA.’”41 
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Similarly, the deposition of mercury into surface water from land applied 

biosolids or landfilled biosolids or amalgam is also minor.42 According to the 2006 EPA 

Mercury Road Map, “based on existing information,” releases of mercury to the land (such as 

land application of biosolids) “are generally not considered to be as environmentally harmful as 

releases to air because the mercury may be less mobile and less likely to reach surface waters 

and fish.”43 

Thus, the contribution of mercury originating from dental office amalgam 

wastewater has little or no effect on the concentration of mercury in the treatment plant’s effluent 

entering surface water or in the methylmercury level in fish. The ADA’s voluntary amalgam 

separator program will further reduce this impact. This underlying reality argues for the 

flexibility inherent in a voluntary approach. 

D. Incremental Collection of Amalgam

1. The Conceptual Model

The incremental benefit of mandatory amalgam separators is the additional 

amount of mercury collected by the mandatory separator rule compared to the amount of 

mercury collected by a voluntary separator program (such as the ADA efforts to implement the 

2007 ADA BMPs as discussed by this submission). Thus, for example, there is no incremental 

benefit in states or localities that have already enacted mandatory separator requirements, where 

separators have already voluntarily been installed, and for the amount of amalgam collected by 

separators that would otherwise be collected by existing programs (such as regulatory programs 

that were based on the pre-2007 BMPs, which did not include separators, but did include several 

other amalgam collection measures). 

There is no benefit to a federal pretreatment requirement if existing law, guidance 

or practice already collects the amalgam in the dental office. 
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2. Corrections to the EPA Analysis

a. Introduction

The ADA generally agrees with EPA’s assessment of the amount of mercury 

discharges from dental offices to surface water, except for the following. 

b. The Size of Particles Entering the Separator in a Dental Office

EPA’s analysis assumes that distribution of amalgam particles entering separators 

in a typical dental office is the same distribution as used in the ISO test and therefore use the 

capture efficiency from those tests (99%). The 2005 Vandeven & McGinnis article, however, 

notes: 

In order to determine the incremental capture efficiency of the 

amalgam separators tested by the ADA under ISO Standard 11143, 

the fate of a 100-mg representative ISO amalgam sample was 

considered. As discussed previously, it was estimated that 80% of 

the dental facilities in the United States are equipped with both 

chair-side traps and vacuum filters, for which average capture 

efficiencies of 68% and 40%, respectively, were identified in the open 

literature. In those dental facilities equipped with both a chair-side trap 

and vacuum filter, an estimated 68 mg of the ISO amalgam sample 

would be captured in the chair-side trap, with approximately 32 mg 

passing on to the vacuum filter. The incremental capture of the vacuum 

filter, at 40%, would retain approximately 13 mg of the 32 mg of 

amalgam that passed the chair-side trap. Therefore, an estimated 81 mg 

of the original amalgam sample would be captured from the combination 

of the chair-side trap and vacuum filter. The remaining 19 mg of the 

amalgam sample would pass on to the amalgam separator, which would 

capture some portion of the 19 mg. According to the ADA sampling 

results, if the entire 100 mg sample were run through the amalgam 

separator at the average 99% ISO capture efficiency, the separator would 

not have captured 1mg of the sample. This 1mg would consist of the 

smallest and most difficult amalgam particles to capture, and, having 

passed the chair-side trap and vacuum filter, would be part of the 19 mg 

left under this illustration. Therefore, the ADA data indicate that, in a 

typical dental facility equipped with both a chair-side trap and vacuum 

filter, the average amalgam separator would capture 18 mg of the 19 mg 

of amalgam that reached the device, for an incremental capture 

efficiency of approximately 95%. Similarly, in the estimated 20% of 

dental facilities that are only equipped with chair-side traps, 

approximately 68 mg of the ISO amalgam sample would be captured in 

the chair-side trap, with about 32 mg passing on to the amalgam 

separator. In these dental facilities, the separator would capture 31 mg of 
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the 32 mg that reached the device, for an incremental capture efficiency 

of approximately 97%.44

Attachment 1 (the new ENVIRON analysis) provides more details and 

explanation. Thus, EPA should use an incremental capture efficiency for separators of 96.4%. 

c. The Percent Capture by Treatment Plants

EPA has proposed to use 90% removal of mercury in amalgam from offices 

without separators by sewerage treatment plants, instead of the 95% used in the Vandeven & 

McGinnis article. As we understand it, EPA would apply one removal efficiency for all 

amalgam entering the sewerage treatment plant (known as a publicly owned treatment works or 

“POTW”). 

The 2005 Vandeven & McGinnis article states: 

an average incremental capture efficiency for the use of amalgam separators of 

approximately 95% was used in the cost-effectiveness analysis. At this efficiency, 

amalgam separators would reduce the estimated discharge of 6.5 tons (5.9 metric 

tons) of mercury in the form of amalgam to POTWs in the United States to 

approximately 0.3 tons (0.3 metric tons). As noted, this 0.3 tons would consist of 

the smallest and most difficult amalgam particles to capture. Amalgam separators 

primarily employ the same physical processes to remove amalgam particles as the 

processes utilized at POTWs to remove particulates (i.e., sedimentation and 

centrifugation), and can generally be expected to remove the same types of 

amalgam particles. Indeed, the amalgam capture efficiencies identified for both 

POTWs and separators from the open literature are both approximately 95%. 

Therefore, it is unlikely that a significant amount, if any, of the 0.3 tons of 

mercury in the form of amalgam particles not captured by amalgam separators 

would subsequently be captured by the downstream POTWs (i.e., the 0.3 tons of 

mercury in the form of amalgam not captured by the separators would consist of 

the same 0.3 tons that is already estimated not to be captured by POTWs).45

Attachment 1 provides an update of the scientific basis for using a sewerage 

treatment plant mercury removal rate of at least 95% for amalgam discharged from offices 

without separators.46
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The reasons for the difference in the estimated 90% mercury removal in EPA’s 

1982 sewerage treatment plant study and the current estimate of a 95% or more removal rate for 

amalgam particles from dental offices without separators are as follows. 

First, the National Association of Clean Water Agencies (“NACWA”) studies 

cited in the 2005 Vandeven & McGinnis peer-reviewed paper are more recent and scientifically 

sound, especially with the use of much lower detection limits.47

Second, it is widely recognized that “[m]unicipal wastewater treatment plants 

(POTWs) are capable of removing 95% of the mercury that enters their systems.”48 In fact, 

many sewerage treatment systems report a greater than 99% removal efficiency.49 

Third, the data in EPA’s 1982 study was collected in the late 1970s and there 

were several methodological limitations of this study, including the lack of representativeness of 

the sample50 and the high detection limits (resulting in limitations on the ability to calculate a 

reliable removal efficiency), among others. 

Fourth, in the late 1970s, the mercury levels in influent, biosolids, and effluent 

was much higher than it is presently, probably reflecting the higher levels of mercury discharges 

in the 1970s.51 This is likely to result in a lower removal rate because dissolved mercury is not 

captured by the features of a sewerage treatment plant that collects amalgam particles. 

Amalgam, on the other hand, is a solid particle that is much heavier than water and is ideally 

suited to be captured by the components of a sewerage treatment plant.52 

In summary, the ADA urges EPA to use at least 95% treatment plant mercury 

removal efficiencies for amalgam discharged from offices without separators and a range of 0% 

to 30% for the small levels of amalgam residuals discharged from offices with separators in its 

final study. 
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d. Percentage of Separators in a Voluntary Program

EPA’s methodology to derive the number of separators that have been installed or 

are required or recommended to be installed is a reasonable approach, but the final estimate of 

the percentage of separators should be updated to include municipalities and other states that 

have adopted such programs since EPA’s estimate was performed. 

EPA estimates that 30% of the dentists have or will install separators, or have or 

will install them due to regulatory guidance recommending it or because of a regulation or law 

(approximately 16.2% of the population of dental offices).53 EPA then estimates that if only 

20% of the dental offices in states not covered by statutes, regulations or recommendations (i.e., 

the other 82.8% of the nation’s dental offices) voluntarily installed separators, the rate of 

separator usage in this group would be approximately 16.8% of the population of dental 

offices.54 A total of approximately 33% of dental offices currently have separators or are 

obligated to install separators, so EPA rounded this estimate down to 30%. 

EPA also estimates that currently 65% of the dentists comply with the pre-2007 

voluntary BMPs that do not include separators.55 The ADA anticipates that as more dentists 

comply with the 2007 ADA BMP, the remaining dentists will be more likely to comply with at 

least the pre-2007 ADA BMPs. 

Both the percentage of dental offices that use a separator and the percentage of 

dental offices that at least use the pre-2007 ADA BMPs are not static numbers. The ADA 

strongly believes that existing information demonstrates that over the long term (years, not 

decades), the percentage of dental offices that install amalgam separators will be considerably 

higher than 20% in States with mandates and nationally higher than 30% for the following 

reasons. 
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First, using the same 20% usage for states not covered by statutes, regulations or 

recommendations, the estimate of separator usage is approximately 43.0%,56 higher than EPA’s 

estimate of 30%. Attachment 3 updates the EPA summary of the status of various state and 

municipal statutes, regulations, and guidance’s that require or recommend the use of separators. 

This Update includes additional states and several municipalities that have required or 

recommended separators. 

Second, even the estimate in Attachment 3 does not include all local separator 

statutes. 

Third, a growing number of new states and municipalities are requiring amalgam 

separators, so the rate of use is certain to increase over the next several years. 

Fourth, the degree of voluntary installation of amalgam separators is likely to be 

higher than the 20% assumed by EPA because the ADA 2007 BMPs now include separators. 

.Many state and local dental associations have been educated and are working cooperatively with 

local and state authorities, and the continued wide spread regulatory activity and education 

efforts have convinced many dentists of the benefits of installing separators. 

A voluntary program is not a “does nothing” program. The ADA will reach out to 

every dentist in the country, seek partnerships with federal and state regulators and separator 

manufacturers, institute training programs and seminars; and continue to support research and 

testing, among other things. As discussed in Section II (D), the ADA has already made progress 

toward the goal of amalgam separators and other best management practices. 

In summary, a voluntary program is likely to exceed EPA’s projections of 65% 

of dentists using the pre-2007 BMPs and 30% of the dentists using separators, given the ADA’s 

continued and extensive efforts to promote the use of the ADA BMPs. 
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e. The Effectiveness of Separators

Amalgam separators are effective in increasing the amount of amalgam that is 

recycled, which the ADA agrees is a benefit. Also, concentrations of mercury generally decrease 

in biosolids after installation of separators. The most important question is whether there are 

releases to the environment that are substantially contributing to the levels of methylmercury in 

fish (as discussed in Subsection (B) above). 

There is no real evidence that separators will decrease mercury levels in treatment 

plant effluent. A visual review of the data (Attachment 2) indicates that there is no clear pattern 

of decreases in treatment plant effluent following the installation of amalgam separators, and 

some data may suggest an increase in the effluent. Neither the individual presentations that 

interpreted this municipal data nor the NACWA study correlated the change in effluent mercury 

concentration over time with separator installations. Some of the treatment plants were 

implementing mercury reduction well before the NACWA study was initiated. 57

3. The Incremental Difference in Amalgam Collected

The benefit of a mandatory separator program is, of course, the incremental 

amount of mercury collected by a mandatory separator program compared to a voluntary 

separator program. ENVIRON has updated its assessment of the fate and transport of mercury 

from dental amalgam and applied these results and EPA’s assumptions concerning the 

percentage of separator being used or required and the percentage compliance with the pre-2007 

ADA BMPs (Attachment 1). 

Since the ADA does not have independent information up which to base an 

estimate of the likely future rate of separator installation and future degree of compliance with 

the recycling component of the ADA’s 2003 BMPs, only choice is to perform a sensitivity 

analysis calculating the amount of amalgam-related mercury that would enter surface water using 
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percentages of amalgam separator use and recycling that range from the baseline (i.e., EPA’s 

assumptions) to 100% (the equivalent of a mandatory separator requirement. For example, EPA 

concluded that 30% of the dentists are either obligated to install separators or will do so 

voluntarily in the near future. Similarly, EPA assumed that of the dentists who have not installed 

separators, only 65% recycle amalgam, i.e., they either disposed of amalgam in medical waste 

incinerators or in landfills. 

ENVIRON performed a sensitivity analysis using as a baseline EPA assumption 

that 30% use of separators and 65% compliance with recycling among the dentists not using 

separators.58 ENVIRON then calculated the amount of mercury entering surface water for the 

baseline use of separators (30%), as well as 50%, 75%, 90%, and 100% use of separators in 

order to calculate the likely decrease in the impact when more than 30% of the dentists install 

separators. ENVIRON used the same model on the fate and transport of mercury from dental 

wastewater as is described in the 2005 Vandeven & McGinnis article, except that the amount of 

amalgam entering the plant is as estimated by EPA in the administrative record and the 

calculation includes the impacts from emissions from medical incinerators and landfills). 

ENVIRON notes, however, that the amount of amalgam entering sewer systems is lower than 

estimated by EPA because the number of amalgam restorations has decreased from 1999 to the 

present (Attachment 1). 

Emissions from land application are de minimis so they are not included in the 

calculation (see Attachment 1 for details). For each calculation concerning the increased benefit 

if more dentists used separators, ENVIRON calculated the benefit, if, as expected, more than 

65% of the dentist comply with these recycling BMPs (see Table 1 below). This analysis is 

consistent with EPA analysis in the administrative record. 
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Table 1: Relative Annual Amount of Mercury Entering Surface Water from Amalgam 

Wastewater 

(Tons per year) 

Compliance with pre2007 BMPs 65% 65% 80% 80% 90% 90% 100% 

Destination of nonrecycled mercury 

Medical 

and 

Biosolids 

incinerator Landfill 

Medical 

and 

Biosolids 

incinerator Landfill 

Medical 

and 

Biosolids 

incinerator Landfill NA 

0% of dental facilities 

using separators 0.532 0.423 0.483 0.421 0.451 0.420 0.419 

30% of dental facilities 

using separators 

0.425 – 

0.447 

0.348 – 

0.371 

0.391 – 

0.413 

0.347 – 

0.370 

0.368 – 

0.391 

0.347 – 

0.369 

0.346 – 

0.368 

50% of dental facilities 

using separators 

0.353 – 

0.391 

0.299 – 

0.336 

0.329 – 

0.367 

0.298 – 

0.336 

0.313 – 

0.351 

0.298 – 

0.335 

0.297–

0.335 

75% of dental facilities 

using separators 

0.264 – 

0.320 

0.237 – 

0.293 

0.252 – 

0.308 

0.237 – 

0.293 

0.244 – 

0.300 

0.236 – 

0.293 

0.236 – 

0.292 

90% of dental facilities 

using separators 

0.211 – 

0.278 

0.200 – 

0.267 

0.206 – 

0.273 

0.200 – 

0.267 

0.203 – 

0.270 

0.200 – 

0.267 

0.199 – 

0.267 

100% of dental 

facilities using 

separators 

N.A. N.A. N.A. N.A. N.A. N.A. 0.175 – 

0.250 

Range Of Assumptions Concerning Use of Separators and Compliance with Pre-2007 BMPS for Those Not Using 

Separators (Assuming 31.25 tons discharged in dental wastewater – ERG’s Calculation)(All Options Include 

Releases from Biosolids Incineration) 

The result of these calculations is that there is little difference in the amount of 

amalgam collected if only 30% of the population of dental offices installed amalgam separators 

compared to 100%. For example, the total release of mercury into surface water (from sewerage 

treatment plant effluent, air emissions from biosolids incineration and medical incinerators) 

decreases from 0.53 tons if no separators (are used and only 65% of the dentists without 

separators use pre-2007 BMPs) down to 0.25 tons if 100% of dentists use separators. 

As the number of dentists that use separators, or at least follow the pre-2007 ADA 

BMPs, increases, the difference in the amount of amalgam collected compared to 100% 

separator use decreases. For example, if 75% of dentists use separators and the compliance rate 

with the pre-2007 ADA BMPs among the 20% of the dentists who do not use separators is 75%, 

and the amalgam is landfilled, the amount of mercury entering surface water would be 0.29 tons 
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– compared to 0.25 tons if 100% of the dentist use separators. That is a reduction of 0.043 tons, 

a relatively small amount by any measure. 

Table 1 provides a sensitivity analysis. The difference in the amount of amalgam 

collected becomes demonstrably small. 

E. Disposal of Collected Amalgam

There is no national information of which we are aware of that provides a 

historical estimate of how dentists dispose of the amalgam waste and whether the disposal 

followed the recommendations in the ADA's 2003 BMPs.59 In this submission, the terms “pre2007-BMPs”60 and “2007 BMPs”61 are used to distinguish the BMPs that were in existence prior 

to the October 2007 BMPs, which added amalgam separators. The ADA developed the BMP 

program to increase the rate at which proper disposal occurred. 

The ADA has been promoting use of the pre-2007 BMP for four years. The ADA 

sponsors training sessions, has prepared videos, and sends information to dentists throughout the 

country. In addition, most state dental associations have implemented the amalgam BMPs and 

perform their own educational efforts. Furthermore, local municipalities, States, and EPA have 

initiated mercury reduction education over the last several years, most, if not all of which, 

include amalgam handling components. 

Moreover, the ADA initiated the development of, and worked with EPA to craft 

an ANSI/ADA specification which describes procedures for storing, and preparing amalgam 

waste for delivery to recyclers or their agents for recycling.62 In addition, the ANSI standard 

gives requirements for the containers for storing and/or shipping amalgam waste. 

Each of these efforts has the same goal --- to inform dentists of the best approach 

to collecting and disposing of amalgam wastewater and providing dentists with the tools needed 

to implement BMPs. 
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The ADA, EPA, the University of Missouri and others performed a study of the 

effectiveness of the use of the ADA pre-2007 BMPs.63 The study concluded that implementing 

the ADA Pre-2007 BMPs (even imperfectly) resulted in a measurable and significant reduction 

in mercury load to the influent wastewater of the treatment plants, as one might expect.64 

Furthermore, the use of the ADA pre-2007 BMPs did not result in a measurable change in 

mercury load to effluent treatment water, similar to preliminary NACWA data (see discussion 

below). Finally, the education and training provided to area dental offices in this study resulted 

in an overall increase in the use and understanding of BMPs. The ADA, state and local dental 

associations believe that more work can and will be done. 

In summary, in the past, the ADA believes that there has been a significant 

increase in the percentage of the dental community that complies with the ADA Pre-2007 BMPs. 

In the ADA’s view, the rate of compliance with the ADA pre-2007 BMPs will continue to 

increase. The ADA is dedicated to continuing its efforts to ensure that all dentists use at least the 

ADA pre-2007 BMPs (see also discussion of the ADA 2007 BMP, below). 

F. Defining the Benefit/Effectiveness of Separators by the Amount of Amalgam 

Collected

The appropriate measure of “effectiveness” and benefit for the pretreatment rule 

is the change, if any, in mercury concentrations in fish tissue caused by installation of amalgam 

separators. The relative impact from installation of separators can be measured by the reduction: 

(1) in the mercury concentration in sewerage treatment plant effluent, combined with, (2) 

reductions of the mercury deposition to surface water from airborne deposition of mercury that 

originated from dental office discharges (e.g., as a result of incineration of biosolids, land 

application of biosolids or landfilling of biosolids or grit chamber waste). Conceptually, these 

are the only potential impacts separators can have on the environment. 
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It is important to understand that because both mandatory and voluntary separator 

programs have the same ultimate goal; it follows that the benefit should be the same in the longterm. 

However, EPA must evaluate the benefit and cost of a mandatory versus a 

voluntary separator program. A mandatory program creates transaction costs for EPA and 

unfunded mandates for state regulators and municipalities. For example, if permits are used, the 

municipality must have personnel develop and issue the permits, perform inspections, and if 

there is a failure to compliance, initiate an enforcement action. Similarly, if formal mercury 

minimize plans are required, these must be created, dentists identified, and similar inspections 

performed. In some jurisdictions, municipalities may either perform sampling or require the 

dentists to sample. The states must review such programs and ultimately EPA must oversee the 

state and local implementation. 

With approximately 100,000 dental offices to be regulated, the limited resources 

at every level of government will be strained to the breaking point, with little or no incremental 

environmental benefit compared to a voluntary program. Much of these costs (and the impact of 

regulatory resources) would be unnecessary if EPA accepted a voluntary program. 

One of the key disagreements that the ADA has with EPA’s analysis is that it 

attempts to define the benefit from (and effectiveness of) amalgam separators in terms of the 

total amount of amalgam collected (i.e., the cost of amalgam separators is divided by the amount 

of amalgam that the separators prevent from going into sewerage treatment plants, as opposed to 

going into the environment). That is, EPA has presumed that all amalgam collected in a dental 

office directly translates into an equivalent reduction of mercury in the environment. This 

assumption is not precautionary,65 it is simply wrong. 
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Treatment plants collect over 95% of amalgam and most of the mercury in the 

biosolids and grit chambers do not re-enter the environment, according to EPA’s own studies. 

Put another way, it is improper to “double count” a benefit that has already accrued to the 

treatment plants. 

EPA’s logic (i.e. that every particle of amalgam collected on the front-end by 

separators would, absent separators, find its way to surface waters and that this contribution 

would be significant) is inconsistent with its prior regulatory evaluations of mercury releases 

from landfills, incinerators, and land application of biosolids. To base a regulatory action on such 

an assumption would violate general principles of administrative law.66 

It is incorrect to assume that all of the mercury in biosolids from dental amalgam 

is released to the environment. EPA itself has concluded that releases of mercury to land (such 

as application of biosolids) “are generally not considered to be as environmentally harmful as 

releases to air because the mercury may be less mobile and less likely to reach surface waters 

and fish.”67 EPA has not announced plans to modify its mercury biosolids limit based on the risk 

from the release of mercury from biosolids. (Of course, should it do so, as we have pointed out 

elsewhere, nothing would prevent EPA from revisiting the issue addressed here.) 

Furthermore, it is inconsistent to make this assumption for dental amalgam, but 

not assume that mercury collected by the pollution controls on coal-fired electric generating 

facilities, hazardous waste incinerators, municipal incinerators, and medical wastes incinerators 

are also released. Similarly, any mercury (from any source) landfilled or land applied would 

need to be considered released to the environment. In fact, all metals would need to have the 

same assumption made. Such an assumption is unsupported by the facts and, when only applied 

to dental amalgam, is arbitrary and capricious. Rather, EPA must make a case-by-case 
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assessment of the actual amount of mercury released and, if the amount of mercury released 

triggers regulatory action, a specific rulemaking initiated. 

As discussed below, ENVIRON has calculated the amount of mercury entering 

surface water as a result of discharges of amalgam wastewater from dental offices and the values 

(even updated) are relatively low) (see Attachment 1). Even this grossly overstates the actual 

environmental benefit from separators. The regulatory history of concern over amalgam 

demonstrates that the regulatory action was not required until EPA set the mercury water quality 

standard at 0.3 ppm and found that fish in many locations contained methylmercury at 

concentrations exceeding the 0.3 ppm limit.68 In other words, the only reason that controls were 

sought on dental office discharges is concern that amalgamated mercury might be the cause of 

the methylmercury levels in fish. However, the vast majority of mercury in amalgam leaving the 

dental office remains intact as amalgam particles in biosolids.69 Thus, the likelihood that dental 

offices are contributing to the methylmercury exceedances in fish is far less than other sources 

that release elemental or other more bioavailable types of mercury. 

Finally, the available data on separator effectiveness reviewed in Attachment 2 

indicates that, even though mercury levels in influent and biosolids should decrease after 

separators are installed, there are no observable decreases in the concentration of mercury in 

effluent following the installation of amalgam separators. As noted in Attachment 2, more 

thorough statistical evaluation of the data would be necessary to evaluate the effect of separators 

on the effluent. 
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G. Conclusion

In summary, there is very little difference between the benefits derived from a 

mandatory versus a voluntary separator program. 

IV. COSTS AND COST-EFFECTIVENESS

EPA requested in its federal register notice information on the cost of alternatives. 

The cost of using an amalgam separator consists of: (1) the cost of purchasing or leasing the 

separator; (2) the cost of installing the separator; (3) the cost of recycling the amalgam collected 

by the separator; and (4) any miscellaneous costs (e.g., such as the labor cost of having an 

employee handle the collection and recycling of the additional amalgam). 

The ADA included separators in its BMPs, primarily because separators allow for 

more amalgam waste to be recycled, which the ADA believes is a best management practice, not 

because the incremental reduction in mercury entering surface water has a significant adverse 

impact on the environment. There is a distinction between the basis and technical support 

needed to adopt a professional guideline (such as the 2007 ADA BMPs) and the level of legal 

and scientific support needed to justify the promulgation of a rule mandating a requirement 

rigidly applicable to every dental office in the nation. In the voluntary approach, citizens, small 

businesses (such as dentists), or corporations may go beyond compliance with the requirements. 

However, if the government imposes mandatory requirements, typically cost and 

cost-effectiveness is examined and some actions may not meet the legal test for imposing 

mandatory requirements. Thus, neither EPA nor the dental community need be concerned about 

cost in deciding to adopt a voluntary program. Even if where to disagree with the ADA on its 

legal authority, EPA could adopt a voluntary program to achieve its mercury reduction goal. 
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Thus, the ADA provides the following cost information because it is relevant to 

whether there is legal support for a mandatory separator program. 

ENVIRON reviewed the literature on costs and has concluded that EPA’s 

information is reasonable (although installations in large cities and in larger dental facilities may 

cost more than the $180 used in the EPA calculations (Attachment 1).70 EPA estimates that the 

annual recycling costs are $600 per year.71 Although this appears reasonable for the present cost 

of recycling, recycling costs are likely to increase over time as recycling may not be available. 

As imports and exports of mercury are banned, the impact is likely to be either a decrease in the 

amount needed to be recycled, which could depress recycling costs, but would end up requiring 

long term storage. In either case, the long-term cost of collecting amalgam is likely to increase 

over time. 

The cost of the various voluntary and mandatory amalgam separator programs is 

provided in Table 2. Again, for simplicity, we used most of the assumptions proposed by EPA 

(even the undercounted installation cost) (which are generally not significantly different from the 

values used by Vandeven & McGinnis, except for installation costs). 
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Table 2: Costs of implementation 

(Millions) 

65% BMP 80% BMP 90% BMP 100% BMP 

0% of dental facilities 

using separators $9.8 $12.1 $13.6 $15.1 

30% of dental facilities 

using separators $34.7 $36.3 $37.4 $38.4 

50% of dental facilities 

using separators $51.3 $52.8 $53.2 $54.0 

75% of dental facilities 

using separators $72.1 $72.7 $73.0 $73.4 

90% of dental facilities 

using separators $84.6 $84.8 $84.9 $85.1 

100% of dental facilities 

using separators $92.9 $92.9 $92.9 $92.9 

Assume $770.85/year for separators and $150/year for BMPs for 100,843 dentists, and $180 installation costs 

(ERG, 2007) that use amalgam. See Attachment 1. 

The cost-effectiveness of collecting amalgam with a separator is the same whether 

30% or 100% of the dentists use separators because cost-effectiveness is the cost per pound of 

amalgam removed from the environment. 

Cost-effectiveness is typically used in regulatory decision making and it is raised 

here because it highlights the fact that some regulatory alternatives (regardless of the cost) do not 

significantly improve the likelihood of achieving the regulatory goal. 

The original 2005 Vandeven & McGinnis peer reviewed article calculated a costeffectiveness of $380 million to $1.14 billion per ton mercury for the incremental reduction in 

mercury collected if amalgam separators are installed compared to full compliance with the 2003 

ADA BMPs. The treatment of costs in that calculation is preferable. However, ENVIRON also 

calculated the cost-effectiveness of amalgam waste separators as approximately $319 million to 

$461 million per ton mercury using the amount of mercury released to surface water described 

above, EPA’s cost and present value assumptions, and assuming 100% use of the pre-2007 ADA 

BMPs. As another check on the sensitivity of the cost-effectiveness calculation, ENVIRON 
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calculated an approximately $232 million to $294 million per ton mercury using using the 

amount of mercury released to surface water described above, the EPA cost assumptions, EPA

present value, and 65% use of the pre-2007 ADA BMPs, assuming non-recycled mercury is sent 

to medical incinerators.72

The new estimate differs from the Vandeven & McGinnis calculation because: (1) 

ENVIRON considered potential emissions from landfills and medical waste incinerators; (2) 

ENVIRON used an installation cost of $180 (as proposed by EPA); and (3) ENVIRON used 

EPA’s more precise present value calculation. 

The new ENVIRON cost-effectiveness calculation differs from EPA’s calculation 

because: (1) ENVIRON uses the amount of mercury entering surface water (not the amount of 

amalgam collected by separators) as the benefit; and (2) the ENVIRON analysis uses a range of 

0% to 30% removal efficiency for the tiny percentage of residuals from amalgam separators that 

are captured by sewerage treatment plants and 95% for removal of discharges from dental offices 

without separators. Regardless of which cost-effectiveness figures are more appropriate, 

mandatory separators are not cost-effective from a regulatory perspective. However, 

nonetheless, regardless of cost-effectiveness based on releases to surface water, the ADA has 

adopted amalgam separators as part of their 2007 BMP because it increases the amount of 

amalgam that is recycled. 

The ADA believes there is no need to use toxicity weighting factors at this stage 

in the cost-benefit analysis because it is more informative to compare the unweighted mercury 

reductions from mandatory amalgam separators with unweighted mercury reductions from a 

voluntary program. 
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Since the methylmercury levels in fish are unlikely to be significantly reduced if 

mandatory separators are installed, the cost-benefit is effectively much higher (i.e., no matter 

how high the costs, there is no benefit --- no significant reduction in the methyl mercury 

concentration in fish tissue). 

Finally, an amalgam separator mandatory regulation would be inconsistent with 

the Small Business Regulatory Enforcement Flexibility Act (SBREFA) because it would force 

the dental community, a collection of SBREFA small businesses, to “bear a disproportionate 

share of regulatory costs and burdens” of dealing with the mercury problem.73

In summary, a voluntary program, of course, need not meet the regulatory costeffectiveness or other cost tests. 

V. CONCLUSION

EPA must decide whether the benefits of using a mandatory versus voluntary 

separator program is worth the costs – particularly given the demonstrable and similar 

environmental benefits achievable through use of a voluntary approach. A voluntary effort to 

implement the ADA voluntary Best Management Practices would be the best approach to the 

shared goal – ensuring that dental offices use separators. 

The ADA respectfully requests EPA to use a voluntary separator program. 
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ENDNOTES 

 

1

 The ADA is the largest dental professional organization in the United States, representing over 155,000 dentists 

including approximately 70% of the active dentists in the US. See ADA Internet site at 

http://www.ada.org/ada/about/index.asp.. 

2

 Much of the support for the EPA calculations is provided in the ADA’s February 20, 2007 submission in this 

proceeding (EPA-HQ-OW-2006-0771-0003) (These comments are found in the administrative record in this matter 

at EPA-HQ-OW-2006-0771-0003. They consist of a cover letter, comments, and various appendices. The pages 

were numbered by EPA in the upper right hand corner) (“ADA Prior Comments EPA-HQ-OW-2006-0771-0003”) 

and the 2005 Vandeven/McGuiness Article (EPA-HQ-OW-2006-0771-0222), An Assessment Of Mercury In The 

Form Of Amalgam In Dental Wastewater In The United States. Jay A. Vandeven and Steve L. McGinnis, Water, 

Air, and Soil Pollution (2005) 164: 349–366, Springer 2005 (“2005 Vandeven/McGinnis Article”). This paper is 

cited, but not provided in the administrative record. The authors have informed the ADA that this paper may be 

reproduced in the administrative record because permission has been granted. 

3

 Such a survey should only occur after the voluntary program has been implemented for a sufficient time to 

measure tangible results. 

4

 For example, the mean level of methylmercury in tissue from fish in Wyoming (based on EPA studies) is 0.095 

ppm, below the water quality standard of 0.3 ppm in fish tissue. See ADA Prior Comments EPA-HQ-OW-2006-

0771-0003 at 36; 62; 70-71; 90-92; 182-183 (February 20, 2007). These concentrations are consistent with the 

results of sampling reported in 2007 that concluded that “[f]ish tissue mercury concentrations in Western U.S. 

streams and rivers were found in a fairly narrow range (90% = 0.02 to 0.2 μg/g [ppm]),” which “strongly suggests a 

broad diffuse source of mercury from atmospheric deposition.” EPA, Proceedings of the 2007 National Forum on 

Contaminants in Fish at 16 of 54, available at 

<http://www.epa.gov/waterscience/fish/forum/2007/pdf/section2b.pdf>. 

5

 ADA Prior Comments EPA-HQ-OW-2006-0771-0003 at .31,50, 101-102, 111, 152, 213-216. 

6

 The dental community is organized in what is called the tripartite system. When a dentist pays membership dues, 

this payment provides a dentist with membership in the ADA, the state dental association, and the local dental 

association. These three levels operate autonomously. Thus, the ADA cannot dictate policy preferences to either 

the state or local dental associations. 

7 See http://www.ada.org/prof/resources/positions/statements/amalgam4.asp. 

8

 ADA, Professional Product Review, Vol. 2, Issue 4: The Bottom Line, Dental Amalgam Separators, Product 

Review at 1 (http://www.orallongevity.ada.org/members/resources/pubs/ppr/0710_ppr.pdf and Dentists, Industry 

Experts Discuss Amalgam Separators, id. at 5. 

9 See 2005 Vandeven/McGinnis Article, as updated by Attachment 1 to these ADA comments. 

10 See http://www.epa.gov/epaoswer/osw/conserve/action-plan/appndx-b.htm. 

11 See generally http://www.ada.org/prof/resources/topics/amalgam.asp. 

12 See OSHA’s Alliance Milestones and Successes webpage, which lists 54 alliances with OSHA, available at 

http://www.osha.gov/dcsp/success_stories/alliances/success_stories.html#ada. ADA has consistently achieved 

milestones and successes that were posted to this webpage since the formation of the Alliance in 2004. 

13 U.S. Department of Labor’s OSHA webpage, available at http://www.osha.gov/dcsp/alliances/ada/ada.html. 
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#9160713 v1 

 14 See 2007 Alliance Annual Report – OSHA and ADA, May 14, 2007, available at 

http://www.osha.gov/dcsp/alliances/ada/ada_annual_report_2006-2007.html. OSHA’s Bloodborne Pathogens 

Standard, promulgated in 1991, and is codified at 29 CFR 1910.1030.

15 Colorado, Department of Public Health & Environment, Pressing Concerns: A Complete Guidebook to 

Environmental Compliance for Colorado Dry Cleaners at preface letter and p. i (Developed with the Support of 

EPA, Region VIII Small Business Administration, and Rock Mountain Fabricare Association, 1998), available 

http://www.cdphe.state.co.us/el/ecac/DCGuide/A-cover-background.pdf. 

16 Options For Dental Mercury Reduction Programs: Information for State/Provincial and Local Governments: A 

Report of the Binational Toxics Strategy at 39, available at 

http://www.epa.gov/region5/air/mercury/dentaloptions3.pdf. See also Memorandum to Jan Matuszko, U.S. EPA. 

Subject: Dental Amalgam Best Management Practices: Summary of Effectiveness, Current Use and Cost - DCN 

04852 at 5 (estimating that 65% of dentists operating within voluntary programs will implement the BMPs given 

that participation rates in voluntary programs vary from 38% to 100%). 

17 See http://www.ada.org/prof/resources/pubs/epubs/update/update_0504.pdf. In 2004, the Minnesota program won 

the annual Governor's Award for Excellence in Waste and Pollution Prevention, MnGREAT! (Minnesota 

Government Reaching Environmental Achievements Together. 

http://www.pca.state.mn.us/oea/mngreat/2004/MnGREAT2004-Web.pdf

18 Memorandum of Understanding Dental Compliance Follow-up Report, Washington State Department of Ecology, 

Publication Number 06-04-011, July 2006 at 3. 

19 Id. at 3. 

20 Id. at 7. 

21 Id. 

22 http://www.mass.gov/dep/service/about08.htm. 

23 New England Zero Mercury Campaign Report Card on Dental Mercury Use and Release Reduction at 11, 

available at http://www.mercurypolicy.org/new/documents/NEZMC_Report_Card_on_Dental_MercuryFINAL.pdf. 

24 Wichita Silver and Mercury BMP Program, Jamie G. Belden, Pretreatment Specialist, Power Point Presentation, 

available <www.kansas.gov/uaa/sbcs/presentations/belden%20jamie%20p2%20case%20studies.pdf> at 12 of 34. 

25 See http://www.wichitagov.org/CityOffices/WaterAndSewer/SewageTreatment/SilverMercury.htm. 

26 Options For Dental Mercury Reduction Programs: Information for State/Provincial and Local Governments: A 

Report of the Binational Toxics Strategy at 23. 

27 See http://proteus.pca.state.mn.us/publications/reports/mercury-wlssd-2001.pdf; 

http://proteus.pca.state.mn.us/publications/reports/mercury-wlssd-2002.pdf; 

http://proteus.pca.state.mn.us/publications/reports/mercury-wlssd-2003.pdf. 

28 MCES October 2007 Newsletter, available at 

http://www.metrocouncil.org/directions/water/water2007/mercuryOct07.htm. 

29 EPA Pretreatment Factors Memorandum at 6 of 45 and see ADA Prior Comments EPA-HQ-OW-2006-0771-

0003, at 27-30; 106-107; 117-118; 133-134; and 201. 
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 30 EPA, Effluent Limitations Guidelines and New Source Performance Standards for the Metal Products and 

Machinery Point Source Category, 68 Fed. Reg. 25,685 (May 13, 2003), available at: 

http://www.epa.gov/fedrgstr/EPA-WATER/2003/May/Day-13/w4258.htm. 

31 For example, EPA “is considering a voluntary approach to listing waters impaired by mercury from atmospheric 

source” (because of “the complexities involved in addressing waters impaired due to atmospheric mercury 

deposition”) which allow a state to “demonstrate[e] that it has begun to make some progress in reducing the mercury 

loadings” and “identify[y] regulatory and non-regulatory controls. Memorandum from Diane Regas, Director, 

Director of EPA's Office of Wetlands, Oceans, and Watersheds, to EPA Regions, Office of Wetlands, Oceans and 

Watersheds, Re: Information Concerning 2008 Clean Water Act Sections 303(d), 305(b), and 314 Integrated 

Reporting and Listing Decisions at 11-12 of 21 (October 12, 2006), available at 

http://www.epa.gov/owow/tmdl/2008_ir_memorandum.pdf (“October 12, 2006 Reporting and Listing Information 

Memo”). This memorandum provides guidance on how to use “alternative pollution control requirements” that 

“may obviate the need for a TMDL,” i.e. “[o]ther pollution control requirements (e.g., best management practices) 

required by local, State, or Federal authority” are stringent enough to implement applicable water quality standards 

(WQS) (see 40 CFR 130.7(b) (1)) within a reasonable period of time.” Id. This guidance provides “EPA’s 

expectation ...that a linkage analysis (i.e., cause-and-effect relationship between a water quality target and sources) 

be included in the ... demonstration.” Id. This approach is consistent with the overarching Office of Management 

and Budget’s (“OMB”) directive that federal agencies “consider alternative regulatory approaches.” OMB, Circular 

A-4, Regulatory Analysis at 7 (September 17, 2003), available at 

<http://www.whitehouse.gov/omb/circulars/a004/a-4.pdf>. 

32 EPA Technical support document for the Voluntary Advanced Technology Incentives Program, November 11, 

1997 (DCN 14488), available at http://www.epa.gov/waterscience/guide/pulppaper/jd/tsd.pdf. 

33 1993 US Public Health Service Dental Amalgam Health Review at 1 and I-44. 

34 1993 PHS Dental Amalgam Health Review at 1 and I-44. 

35 ADA 1999 Survey, cited in the 2005 Vandeven/McGinnis Article”). 

36 ADA, Economic Impact of Regulating Amalgam, Public Health Reports. September–October 2007 /Volume 122. at 

657, 659-660, available at <http://www.ada.org/prof/resources/topics/amalgam_economic_impact.pdf> 

(Attachment 3). 

37 The rate of amalgam use has declined 3.7% per year over the last 12 years prior to 2005. Id. Thus, if this rate has 

continued in the three years since 2005, the 2008 rate of amalgam use should be approximately 46.67 million 

amalgam restorations (approximately 20.5% of the restorations). 

38 EPA has rightly concluded that the “choice of dental treatment rests solely with dental professionals and their 

patients” and EPA “does not intend to second-guess these treatment decisions.” Letter from Tracey Mehan, 

Assistant Administrator of the Office of Water to William Walsh (on behalf of the ADA) at 1 (May 13, 2003). 

Nonetheless, at the meeting between EPA and ADA in the fall of 2007, EPA requested information on the cost of 

banning amalgam as a dental restorative material. A recent, peer reviewed article concluded that a ban “will 

increase dental expenditures about $8.2 billion in the first year and $98.1 billion from 2015 through 2020 and would 

result in 15.4 million fewer needed restorations,” thereby decreasing utilization of dentists while increasing 

untreated disease. ADA, Economic Impact of Regulating Amalgam, Public Health Reports. September–October 

2007 /Volume 122. at 657, 660, 657, available at 

http://www.ada.org/prof/resources/topics/amalgam_economic_impact.pdf. In most cases, insurance and 

Medicare/Medicaid would not cover these increased costs. 

39 These legal arguments were made in much more detail in ADA’s February 2007 Comments; see EPA-HQ-OW2006-0771-0003, at p.36- 43; 64; 75; 89-92; 95-97; 119-120; 144-146; 171-176.; 228-233. 
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 40 See ADA Prior Comments EPA-HQ-OW-2006-0771-0003, at 29-32; 50-52; 54-55; 62; 69-70; 101-102; 111-

113;136-137; 152-153; 187-190; 210-222; 227. 

41 ADA Prior Comments EPA-HQ-OW-2006-0771-0003, at 38 and 232-33. 

42 ADA Prior Comments, EPA-OW-2006-0771 at 54-55; 204-208; 213-215. 

43 EPA’s Road Map, Addressing Mercury Releases at 28 (July 2006), available at 

<http://epa.gov/mercury/pdfs/I_HgReleases.pdf>. The mercury in amalgam is bound into the mixture and the 

mercury in the amalgam in biosolids is less likely to be released into the air. The study cited by EPA in the 

administrative record is limited and measured mercury from all sources, not just mercury from amalgam and, 

therefore, was not a measure of the likelihood of mercury in amalgam being released from soil. 

44 2005 Vandeven/McGinnis Article at 360-361. 

45 2005 Vandeven/McGinnis Article at 361. 

46 Attachment 1 also discusses the support for the use of between 0% to 30% removal for the very small amount of 

amalgam discharged when separators are present. 

47 See Attachment 1. 

48 http://dnr.wi.gov/org/caer/cea/mercury/potw.htm. "The physical processes used in POTWs remove about 95% of 

the mercury received in wastewater." Statement Of Ephraim King Director, Office Of Science And Technology 

U.S. Environmental Protection Agency Before The Subcommittee On Domestic Policy Of The Committee On 

Oversight And Government Reform United States House Of Representatives (November 14, 2007), available at : 

<http://oversight.house.gov/documents/20071115094710.pdf> at 3 of 7. 

49 Madison Metropolitan Sewerage District, Mercury Pollutant Minimization Program at Appendix C (PMP). 50 The samples “were not meant to be a statistically valid representation of all POTWs in the country.” EPA, Fate of 

Priority Pollutants in Publicly Owned Treatment Works: Final Report, Volume 1 at 7 (EPA 440/1-82/303, 

September 1982). 

51 EPA, Fate of Priority Pollutants in Publicly Owned Treatment Works: Final Report, Volume 1 at 36, 39, 41, 47, 

49, 52, 57, (EPA 440/1-82/303, September 1982). 

52 See Attachment 1. 

53 Memorandum from Derek Singer, ERG, to Jan Matuszko, EPA, Subject: Dental Amalgam Separators: Summary 

of Removal Efficiencies, Current Use and Cost Effectiveness (DCN 04851) at 5 (September 26, 2007). 

54 Memorandum from Derek Singer, ERG, to Jan Matuszko, EPA, Subject: Dental Amalgam Separators: Summary 

of Removal Efficiencies, Current Use and Cost Effectiveness (DCN 04851) at 5 (September 26, 2007). 

55 Memorandum from Derek Singer, ERG, to Jan Matuszko, EPA, Subject: Summary Information on Current 

Dischargers of Mercury in the Form of Dental Amalgam from Dental Offices to Publicly-Owned Treatment Works 

(DCN 04853) at 5 (September 26, 2007). 

56 The 43.0% figure is derived as follows. There are 28.7% of the dental offices nationwide that are now or in the 

future subject to state and local statutes, regulations or guidance requiring separators (Attachment 3). Another 

14.3% dental offices are expected to voluntarily install separators (using EPA’s assumption that 20% of the dentists 

not subject to mandatory requirements will voluntarily install separators ((100%-28.7) times 0.2 = 14.3%)). Thus, 

28.7% plus 14.3% = 43.0%. 
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 A final regulatory approach is still being developed in Louisiana, but it appears that pre 2007 BMPs will be 

required there. Act 126 of the 2006 Louisiana Legislature (available at 

<http://www.legis.state.la.us/billdata/streamdocument.asp?did=395483>) requires practices within the industry to 

capture unused dental amalgam product and waste dental amalgam removed from fillings. It and authorizes the 

Louisiana Department of Environmental Quality ("LDEQ") to prepare and publish best management practice 

guidelines for dental offices and laboratories to facilitate. The LDEQ's February 2007 guidance on pollutant 

minimization plans (“MMPP,” available at 

<http://www.deq.louisiana.gov/portal/Portals/0/organization/Hgminimizationplan2-07.pdf>) references the pre-2007 

ADA BMP. It is, therefore, anticipated that the pre-2007 ADA BMPs will be required for the 1,586 dentists in 

Louisiana. As a result, dentists in Louisiana should be fully in compliance with the pre-2007 BMPs (not the 65% 

estimated by EPA). Note that Attachment 1 includes calculations assuming that all dentists in states and 

municipalities without separator requirements could have up to 35% of the dentists not complying with the pre-2007 

ADA BMPs. In the case of Louisiana that is an underestimate. 

57 The ADA is unable to determine when the separators were installed in the case of each treatment plant, making it 

difficult ascertain the true “effect” of the installations. Most, if not all of the reports and presentations reviewed by 

the ADA, did not take into account confounding factors. For example, some chemicals like sodium hypochlorite, 

which can have very high concentrations of mercury (e.g., Clorox® and Comet® can have microgram per kilogram 

levels of mercury), could be contributing significant amounts of mercury to treatment plant effluents. Also, the 

trends in mercury concentration in effluent must be understood in the context of the overall mercury reduction 

programs implemented by the municipality. For example, most treatment plants that have historic data show a more 

dramatic decrease in the mercury concentration in influent, biosolids, and in effluent prior to the installation of 

separators. Both prior to and during the installation of separators, other significant mercury reduction program have 

been instituted nationwide. For example, the majority of dental offices that initially implemented the pre-2007 ADA 

Best Management Practices are contributing to significant reductions that are now intermingled with any reductions 

from the separators. Thus, any analysis of the impact of separators must take into account these other confounding 

factors. 

The NACWA analysis includes attempts to correlate the number of dentists per million gallons of treatment plant 

flow. This analysis is not based on accepted statistical methods (as far as can be determined from the publicly 

available information). More importantly, the mere existence of a high number of dentists per million gallons of 

flow does not fairly indicate a given dental community’s contribution to mercury in treatment plant effluent. Indeed, 

a number of dental offices in a community are highly correlated with high population and an urban setting. Thus, 

the mercury in the influent and effluent may be more a function of the larger number people, the greater use of 

mercury-containing products, and a greater likelihood of industrial and other nondental commercial contribution. 

The ADA believes that the data as now analyzed is helpful but a more detailed statistical analysis of the existing 

data (perhaps with an attempt to correlate the timing of the institution of BMPs, amalgam separators) would 

probably be useful. 

58 Since the mandatory requirements for using separators also include mandatory use of recycling, the sensitivity 

analysis assumes the dentists who install separators recycle their amalgam. 

59 ADA web site, available at <http://www.ada.org/prof/resources/topics/amalgam_bmp.asp>), also see Attachment 

1 to these Comments. 

60 See ADA Internet site, available at <http://www.ada.org/prof/resources/pubs/epubs/csa/communique_1106.htm >. 

The pre-2007 BMP is in the administrative record. 

61 ADA 2007 BMPs can be found at <http://www.ada.org/prof/resources/topics/topics_amalgamwaste.pdf>) and are 

in the administrative record in this matter. 

62 ANSI/ADA Specification 109: Procedures for Storing Dental Amalgam Waste and Requirements for Amalgam 

Waste Storage/Shipment Containers. This standard has been submitted by the ADA as part of the Administrative 

Record. 
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 63 University of Missouri, Extension, Brief Summary Report: Maximizing Voluntary Reductions In Dental 

Amalgam Mercury, Reduction in Mercury Discharges (EPA # E0000127, PI-98765101-0, November 2007), which 

was previously submitted to EPA on the record. This is the executive summary). The J. Bowman, Power Point 

Presentation to the National Association of Clean Water Agencies ("NACWA"), The American Dental Association: 

BMPs and More (2007) (also in the administrative record) includes plots of the data on the effectiveness of the pre2007 BMPs). 

64 Also, use of the pre-2007 BMPs did not result in a measurable change in biosolid mercury levels. This particular 

result is unexpected and may be due to study limitations. 

65 Of course, the Clean Water Act has not been amended to adopt the precautionary principle, no less this extreme 

assumption. 

66 There are evaluations by authors who are affiliated with EPA, but no EPA regulatory determination has required 

reduction of such a small level of mercury releases. For example, EPA has not proposed to lower the biosolids 

limits and EPA has not required emissions controls on many air emission sources. ADA Prior Comments EPA-HQOW-2006-0771-0003, at 41-42; 51-52; 112-113. 

 

67 EPA’s Road Map, Addressing Mercury Releases at 28 (July 2006), available at 

<http://epa.gov/mercury/pdfs/I_HgReleases.pdf>. The mercury in amalgam is bound into the mixture and the 

mercury in the amalgam in biosolids is less likely to be released into the air. The study cited by EPA in the 

administrative record is limited and measured mercury from all sources, not just mercury from amalgam and, 

therefore, was not a measure of the likelihood of mercury in amalgam being released from soil. 

68 In fact, analytical techniques had to be developed to allowed measurements of nanogram per liter (“ng/L” or 

“ppt”) levels of mercury in effluent. 

69 For example, Stone reports that 99.636% of the mercury in amalgam is bound into the amalgam particle and only 

0.0013% is methylmercury. See Memorandum from Derek Singer, ERG, to Jan Matuszko, EPA, Subject: 

Summary of Information on Current Discharges of Mercury in the Form of Dental Amalgam from Dental Offices to 

Publicly-Owned Treatment Works (DCN 04853) at 2 (September 26, 2007). 

70 For example, SolmeteX.(one of the largest suppliers of amalgam separators) indicates that the cost of installation 

is $250. http://www.wwdmag.com/Mercury-From-the-Dentists-Chair-to-Public-Treatment-Works-article8496. 

Also, “Cost of amalgam separators can vary, but are relative to the size of the dental operation. Prices 

listed on the ... table [listed below] are based on information gather by PACE from manufacturers in 

September of 2005.” 

Table of estimated annual cost for amalgam separators: PACE Resource Sheet 2006 

Small (1-4 chairs) Medium (5-12 chairs) Large (+12 chairs)

Purchase $200-1200 $666-2200 $2500-8800

Installation $100-200 $125-260 $200-1000

Maintenance $0-200 $0-200 $0-200

Replacement $50-750 $75-750 $500-2100

Estimated annual cost $185-940 $257-974 $1740-4060

City of Boulder Dental Wastewater Mercury Reduction –Program Overview, Attachment 1 – WRAB August 21, 

2006 at 4, available at 

http://www.bouldercolorado.gov/files/Utilities/Industrial%20Pretreatment/amalgam_program_overview.pdf. 

 

71 Memorandum from Derek Singer, ERG, to Jan Matuszko, EPA, Subject: Dental Amalgam Separators: Summary 

of Removal Efficiencies, Current Use and Cost Effectiveness (DCN 04851) at 3-4 (September 26, 2007). 
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 72 Values are $335 million to $481 million if you assume non-recycled mercury is sent to landfills. See Attachment 

1. 

73 ADA believes that the dental industry is comprised almost entirely of SBREFA small businesses under 13 CFR § 

121.201.