PUEBLO DENTAL MERCURY POLLUTION PREVENTION PROJECT 

FINAL REPORT

AUGUST 31, 2004 

Prepared for: 

Colorado Department of Public Health and Environment 

4300 Cherry Creek Drive South 

Denver, Colorado 80246 

Prepared by: 

Tetra Tech EM Inc. 

1099 18th Street, Suite 1900 

Denver, Colorado 80207 
 

i

TABLE OF CONTENTS 

EXECUTIVE SUMMARY .................................................................................................................... ES-1

DENTAL MERCURY OVERVIEW............................................................................................................1

Dental Mercury in Wastewater .................................................................................................................1

Bioavailability of Dental Mercury ............................................................................................................2

Dental Mercury Reduction Technology....................................................................................................3

PROJECT APPROACH ...............................................................................................................................3

Phase 1 Procedure.....................................................................................................................................3

Task 1-1: Initiate Pilot Project and Obtain and Review Existing Dental Survey ................................4

Task 1-2: Create Survey for Pueblo Dentists.......................................................................................4

Task 1-3: Execute Baseline Dental Survey..........................................................................................4

Task 1-4: Write Baseline Dental Survey Summary Report .................................................................5

Phase 2 Procedure.....................................................................................................................................5

Task 2-1: Obtain Colorado Dental Association (CDA) Support..........................................................5

Task 2-2: Form Advisory Team...........................................................................................................5

Task 2-3: Write Fact Sheet...................................................................................................................5

Task 2-4: Hold Dental Mercury Seminar and Panel Discussion..........................................................5

Task 2-5: Follow Up with Dentists......................................................................................................6

Task 2-6: Write Summary Report........................................................................................................6

Phase 3 Procedure.....................................................................................................................................6

Task 3-1: Create Survey for Pueblo Dentists.......................................................................................6

Task 3-2: Execute Follow-Up Dental Survey ......................................................................................6

Task 3-3: Write Final Pueblo Dental Mercury Summary Report ........................................................6

Phase 1 Summary......................................................................................................................................7

Phase 2 Summary......................................................................................................................................8

Phase 3 Summary......................................................................................................................................8

Value and Content of Outreach Materials and Seminar/Panel Discussion ...........................................9

Overall Effectiveness of the Outreach Effort........................................................................................9

Installation of Amalgam Separators....................................................................................................10

Change in Recycling Practices............................................................................................................11

Transferability Statewide ....................................................................................................................11

CONCLUSIONS.........................................................................................................................................12

Use of Surveys for Feedback ..................................................................................................................12

Value, Content, and Effectiveness of Outreach Materials and Seminar/Panel Discussion.....................12

Transferability of Outreach Effort to Other Colorado Communities......................................................13

Value of the Voluntary Approach...........................................................................................................13
 

ES-1

EXECUTIVE SUMMARY 

The Colorado Department of Public Health and Environment (CDPHE) contracted Tetra Tech EM Inc. 

(Tetra Tech) to implement a three-phase project focused on reducing mercury releases in wastewater from 

dental offices. Phase 1 of this project involved conducting a survey of dental professionals in Pueblo to 

establish a baseline of the information, resources, and equipment currently used by or available to 

dentists. The survey was also intended to identify the barriers to implementing best management 

practices (BMPs) and best available technologies (BATs) for mercury in dental offices. Phase 2 involved 

developing and implementing a targeted outreach program to provide dental professionals with 

information on BMPs and BATs for mercury and eliminate barriers to BMP and BAT implementation. 

Phase 3 involved conducting a follow-up survey of dental professionals in Pueblo to evaluate the 

effectiveness of the project. 

The Phase 1 baseline survey results response rate among dentists was 69 percent and among practices was 

78 percent. The results led to the following general conclusions: 

• Most dentists use chairside traps (97.5 percent) and very few (2 percent) use amalgam separators. 

• Some dentists recycle mercury-containing waste, but many dispose of mercury-containing waste 

as medical waste, in the trash, or through some other form of disposal. 

• Survey responses suggest a general receptiveness to outreach efforts. 

The Phase 2 outreach program was based on Phase 1 survey responses. It involved obtaining Colorado 

Dental Association support, forming a project advisory team, writing a dental mercury fact sheet and 

BMP insert, holding a dental mercury seminar and panel discussion, following up with dentists that did 

not attend the seminar and panel discussion, and writing a summary letter report. 

For Phase 3, Tetra Tech mailed a follow-up survey to 67 dentists representing 56 practices in Pueblo. 

Twenty one dentists (31 percent) from 19 practices (34 percent) responded to the follow-up survey. 

Seventeen of the dentists that responded to the follow-up survey also responded to the baseline survey. 

The follow-up survey led to the following general conclusions: 

• Surveys are a useful tool for obtaining feedback regarding direction of a project and results. 

• Follow-up surveys should be conducted 6 months to 1.5 years after project implementation to 

gather actual project results in response to outreach. 

• The level to which dentist felt informed increased during the course of the project. 

• The willingness to install a free amalgam separator increased from the baseline to the follow-up 

survey. 

• Ninety percent of the dentists in the follow-up survey indicated that they were already recycling 

all mercury-containing wastes or planned to as a result of the outreach efforts. 

• The tools developed for the Pueblo dental mercury pollution prevention project are directly 

transferable to other Colorado communities. 

• The level of adoption of dental mercury BMPs and BATs is limited in voluntary programs. For 

example, many dentists will not install amalgam separators unless it is required by law. 

However, offering to install amalgam separators free of charge did affect Pueblo dentists’ interest 

in installing amalgam separators. 
 

1

PUEBLO DENTAL MERCURY POLLUTION PREVENTION 

FINAL REPORT

In August 2003, the Colorado Department of Public Health and Environment (CDPHE) contracted Tetra 

Tech EM Inc. (Tetra Tech) to implement a three-phase project focused on reducing mercury releases in 

wastewater from dental offices. This project was implemented on a pilot basis in Pueblo, Colorado, using 

supplemental environmental project funds. This project was also a preliminary effort to provide 

compliance assistance to publicly owned treatment works (POTWs) in Colorado. Some Colorado 

POTWs are charged with meeting new, lower discharge limits for mercury and with protecting 

Colorado’s waterbodies and sensitive ecosystems. This document is a final report summarizing the 

project. The document discusses the environmental concerns associated with dental mercury, the project 

approach, project results summary, and conclusions and recommendations. 

DENTAL MERCURY OVERVIEW 

Mercury is a heavy metal long known to be associated with serious health effects; it is a known 

neurotoxin, slows fetal and child development, causes irreversible brain damage, and harms ones ability 

to walk, talk, see, and hear (Mercury Study Report to Congress, Volume V: Health Effects of Mercury 

and Mercury Compounds, U.S. Environmental Protection Agency, 1997.) Mercury can be released into 

the environment from natural or man-made sources. When mercury enters a water body (for example, 

through air deposition or direct discharge), it can bioaccumulate in fish tissue in its most toxic form, 

methylmercury. Humans and wildlife are exposed to toxic mercury primarily through ingestion of 

contaminated fish. CDPHE has issued fish consumption advisories for several reservoirs in Colorado 

(including McPhee and Narraguinnep Reservoirs) as a result of unacceptably high mercury levels. 

Dental Mercury in Wastewater 

POTWs play a vital role in protecting Colorado’s waterbodies and sensitive ecosystems by treating 

wastewater from households, industries, and businesses. Wastewater treatment processes remove solids 

and organic materials from the incoming wastewater and treat the solids, some of which may be applied 

to farmland soil. Metals, including mercury, are of concern to POTWs because they are not degraded or 

destroyed by the treatment processes. Mercury that enters POTWs in wastewater may either settle out 

into the biosolids or pass through the plant and be discharged to receiving waters. Although POTWs are 

not the most significant source of mercury to all Colorado reservoirs, POTWs have been identified as one 

of the sources that contribute to unacceptably high concentrations of mercury in fish. 

Until recently, Colorado POTWs were not subject to permit limits for discharge of mercury because an 

effective method for monitoring low-level concentrations of mercury in either stream segments or POTW 

effluent did not exist. However, with the promulgation of the standard method for analysis of mercury in 

wastewater (Method 1631, Revision B, U.S. Environmental Protection Agency (EPA) Office of Water, 

May 1999), detection levels for mercury in parts per trillion are now possible and easy to detect. As a 

result, CDPHE initiated a process to review and revise mercury discharge limits for POTWs throughout 

the state. As new permits are issued, many POTWs will face significant challenges in meeting lowered 

discharge limits for mercury. These POTWs may pursue either voluntary or mandatory mercury control 

programs to reduce levels of mercury entering the POTW. 

Studies conducted throughout the United States have shown that dental clinics are a measurable source of 

mercury that enters POTWs. Dental amalgam, commonly used for filling cavities in teeth, contains about 

50 percent mercury. Other metals present in dental amalgam include copper, tin, silver, and zinc. In the 

process of placing or removing amalgam fillings, mercury and other metals are conveyed to sewage 

treatment plants. For example, in the report “An Evaluation of the Sources, Impacts, and Controls of 
 

2

Mercury” (February 2002), Al Garcia of the Littleton-Englewood Wastewater Treatment Plant estimated 

that dental clinics contribute 9.26 pounds of mercury, or 62.2 percent of the total annual mercury loading, 

to the Littleton-Englewood Wastewater Treatment Plant in Colorado each year. A May 2002 research 

article published by the American Dental Association (ADA) cited a 1993 study by the California Water 

Pollution Control Association (CWPCA). The CWPCA study was based on wastewater samples taken at 

the connection to the sewer. The CWPCA study concluded that dentists discharge an average of 35 

milligrams of mercury as amalgam into the sewer per day. According to the ADA article, the CWPCA 

study, a 1997 Massachusetts Water Resource Authority study and a 1991 Municipality of Metropolitan 

Seattle study, dentists could contribute from 8 to 14 percent of the total mercury load to wastewater 

treatment plants. Although the relative contribution of dental mercury amalgam to the national mercury 

pollution problem may be low compared to other sources (such as power plants), better detection 

technologies and stricter mercury discharge limits in POTWs result in the need to examine sources that 

discharge to the POTWs and dental amalgam remains a significant source for mercury to POTWs. 

Bioavailability of Dental Mercury 

Most controversy and discussion on dental mercury focuses on whether the mercury released from 

dentists is “bioavailable.” Bioavailability is the ability of a substance to be absorbed by an organism. 

The bioavailability of incinerated mercury amalgam is not debated. Incineration is generally believed to 

release the mercury in a bioavailable form that can settle directly into surface water or deposit on land 

surfaces and be transported to waterbodies by runoff. Medical waste and other forms of waste that may 

contain mercury, such as sludge from POTWs, may be shipped out of state for disposal and are 

incinerated in some states. 

For mercury amalgam that is not incinerated or otherwise altered, ADA currently maintains that mercury 

amalgam released directly to the environment is not bioavailable. Conversely, the Association of 

Metropolitan Sewerage Agencies (AMSA) maintains there is too much uncertainty regarding the 

bioavailability of dental mercury to conclude definitively that it is not bioavailable. 

Based on ADA’s position that mercury is not bioavailable if it is not incinerated, ADA published a set of 

best management practices (BMPs) for amalgam waste. According to Best Management Practices for 

Amalgam Waste released by the ADA in February 2003: 

“Although mercury in the form of dental amalgam is very stable, amalgam should not be 

disposed of in the garbage, infectious waste “red bag,” or sharps container. Amalgam 

should also not be rinsed down the drain. These cautions are important because some 

communities incinerate municipal garbage, medical waste, and sludge from wastewater 

treatment plants. If amalgam waste ends up in one of these incinerated waste streams, 

the mercury can be released to the environment due to the extremely high temperatures 

used in the incineration process...The ADA strongly recommends recycling as a best 

management practice for dental offices.” (Italics added) 
 

3

Dental Mercury Reduction Technology 

According to Phase 1 survey responses (see Project Approach), many dentists in Pueblo have chairside 

traps. Chairside traps collect particles, including dental amalgam, in a disposable or reusable filter. 

Disposable filters are recommended because of the difficulty in effectively removing amalgam particles 

from reusable traps without spilling them into the drain or garbage. Chairside trap filters are available 

with different size meshes for capturing particles. The higher the mesh filter number, the smaller particle 

size it will capture. For example, a 100 mesh filter will capture more and smaller particles than a 40 mesh 

filter. For this reason, higher mesh filters are recommended for mercury amalgam removal than lower 

mesh filters, but may require more frequent replacement or cleaning. 

Amalgam separators remove mercury amalgam from dental wastewater by using one or multiple 

technologies including sedimentation, filtration, centrifugation, and ion exchange. The ADA studied 12 

amalgam separators and published a report on their performance in the May 2002 edition of the Journal of 

the ADA (JADA)1

. According to the JADA article, all 12 amalgam separators removed more than 96 

percent of the mercury amalgam in wastewater, exceeding the ISO 11143 requirement of 95 percent 

amalgam removal efficiency. A recent dental mercury study in Minnesota showed that with amalgam 

separators in place at most dental offices, mercury levels in POTW sludge declined by as much as 29 to 

44 percent2

. 

Dental care professionals have an opportunity to reduce mercury releases to the environment by using 

BMPs and best available technologies (BATs). Only one dentist in Pueblo who responded to the baseline 

survey indicated using an amalgam separator. Studies conducted in Boulder and Fort Collins, Colorado, 

and throughout the United States, show that dental professionals vary in use of BMPs and most dental 

professionals do not use BATs for mercury recovery. Based on these considerations, the dental sector is 

an ideal candidate for increased mercury pollution prevention (P2). 

PROJECT APPROACH 

The dental mercury P2 project was divided into three phases. Phase 1 of this project involved conducting 

a survey of dental professionals in Pueblo to establish a baseline of the information, resources, and 

equipment currently used by or available to dentists. The survey was also intended to identify the real or 

perceived barriers to implementing BMPs and BATs for mercury in dental offices. Phase 2 involved 

developing and implementing a targeted outreach program to provide dental professionals with 

information on BMPs and BATs for mercury and eliminate barriers to BMP and BAT implementation. 

Phase 3 involved conducting a follow-up survey of dental professionals in Pueblo to evaluate the 

effectiveness of the project. The following sections summarize each phase of the project in more detail. 

Phase 1 Procedure 

Phase 1 of this project was divided into four tasks intended to set the direction of the project. Each of 

these tasks and the work accomplished during the tasks are summarized in this section. 

 

1

 Laboratory Evaluation of Amalgam Separators. JADA, Volume 133, May 2002. pp 577. 2

 Take Preventive Action Now. Capture Amalgam so it Doesn’t Release Mercury, Minnesota Dental Association 

and Minnesota Metropolitan Council, March 2003 
 

4

Task 1-1: Initiate Pilot Project and Obtain and Review Existing Dental Survey

A considerable amount of information regarding P2, BMPs, and BATs for dental mercury existed from 

various initiatives in Colorado and other states. As it began work on this project, Tetra Tech conducted 

Internet research to obtain information on existing dental mercury initiatives and related information. 

Tetra Tech gathered information by: 

• Reviewing existing surveys and other information from a recent dental mercury initiative 

conducted by Partners for a Clean Environment, a non-profit organization in Boulder, Colorado 

• Conducting Internet searches for dental mercury BMPs and BATs (overall Internet searches, P2 

web site searches, ADA web site searches, and technology internet sites) 

• Identifying and contacting dentists and other dental mercury experts to discuss BMPs and BATs 

dentists have successfully implemented 

After Tetra Tech completed its research and drafted a survey for Pueblo dentists (see Task 1-2), CDPHE 

and Tetra Tech held a kickoff meeting with project stakeholders. Meeting attendees included 

representatives from: 

• CDPHE: 

- Sustainability Division 

- Oral Health Program 

- Water Quality Control Division 

- Air Pollution Control Division 

• Pueblo City and County Health Department 

• Colorado Mental Health Institute Dental Office 

• Representatives from dental related 

organizations 

• Private practice dentists from Pueblo 

Task 1-2: Create Survey for Pueblo Dentists

Based on its research in Task 1-1, Tetra Tech created a survey and cover letter for dentists and dental 

clinics in Pueblo. The survey required about 5 to 10 minutes for each dental office and clinic to complete 

and asked the respondents to address the following: 

• Current use and disposal of mercury amalgam 

• Use and maintenance of mercury removal equipment 

• Mercury waste collection and mercury waste disposal procedures 

• Barriers to using mercury P2, BMPs, or BATs 

• Effective outreach methods 

Task 1-3: Execute Baseline Dental Survey

Tetra Tech sent the cover letter and survey to all dentists in Pueblo for which it identified an address. The 

final list included 59 dental offices and clinics and 70 dentists in Pueblo. The response goal for the 

baseline survey was at least 45 percent of dentists and dental clinics in Pueblo. 

To meet or exceed this response rate, Tetra Tech: 

• Attended a study group meeting of dentists, explained the project, and requested that attendees fill 

in the survey and provide any relevant feedback 

• Sent surveys on CDPHE, City and County of Pueblo Health Department, and City of Pueblo 

letterhead by mail in envelopes with State of Colorado return address. Included with each survey 

were a cover letter and an addressed, postage-paid envelope that could be used to return the 

survey 

• Telephoned all dental offices and clinics that had not returned the survey within 2 weeks of 

receipt. (Sixteen dentists or dental practices returned the survey without including their name) 
 

5

Task 1-4: Write Baseline Dental Survey Summary Report

After Tetra Tech received the survey responses, it wrote a report that summarized the project and the 

results of the Phase 1 survey. 

Phase 2 Procedure 

Based on the research Tetra Tech completed for this project and on the analysis of the survey results, 

Tetra Tech concluded that the Pueblo dental community would be best served by a clear, easy-tounderstand summary of dental mercury issues and BMPs and access to information regarding dental 

amalgam separators. This section discusses Tetra Tech’s Phase 2 procedure. 

Task 2-1: Obtain Colorado Dental Association (CDA) Support 

Tetra Tech contacted CDA and requested to present the project overview and Phase 1 project results to 

the CDA executive committee. The purpose of the presentation was to gain support for the project. CDA 

agreed to sit on the advisory team (see Task 2-2), sponsor the fact sheet (see Task 2-3), speak at the 

seminar and panel discussion (see Task 2-4), and provide any other support it could for the project, such 

as distributing outreach materials to its membership. 

Task 2-2: Form Advisory Team

At the beginning of the project, CDPHE and Tetra Tech held a kickoff meeting (see Task 1-1) with 

representatives from CDPHE, Pueblo City and County Health Department, dentists, and representatives 

from dental related organizations. These individuals, as well as the president of CDA became the project 

“Advisory Team,” giving input to the direction of the project as necessary. 

Task 2-3: Write Fact Sheet

Tetra Tech researched and wrote a concise 4-page fact sheet regarding dental mercury that was specific to 

Pueblo dentists. Subject matter for the fact sheet included: 

• A brief summary of environmental health concerns associated with mercury and mercury 

amalgam 

• Overview of regulations associated with mercury amalgam nation-wide and within Colorado 

• Details regarding dental mercury amalgam separators, including a description of how amalgam 

separators work, what different types are available, why they are better at removing mercury 

amalgam than chairside traps, costs, vendor names, vendor contact information, and other 

references 

• Details on recycling dental mercury amalgam, including vendor names and contact information, 

steps for recycling dental amalgam waste, and references 

• BMPs for handling dental mercury, especially any endorsed by ADA 

• References for additional information related to dental mercury 

The fact sheet was reviewed by advisory team members, dental amalgam recyclers and dental amalgam 

separator vendors. Tetra Tech worked with a graphic artist to ensure that the fact sheet looked appealing 

and professional. In addition to the Pueblo-specific fact sheet, Tetra Tech wrote a generic fact sheet 

appropriate for a state- and nation-wide audience. 

Task 2-4: Hold Dental Mercury Seminar and Panel Discussion

Tetra Tech organized and held a dental mercury seminar and panel discussion for dentists that covered 

relevant information on: (1) project overview and CDA perspective, (2) regulatory outlook for Colorado 

dentists, with emphasis on Pueblo dentists, (3) amalgam separators, and (4) dental amalgam recycling. 

The seminar and panel discussion was free and offered to all staff at all Pueblo dental offices and clinics. 
 

6

Speakers included the CDA president and experts to discuss the regulatory outlook for Pueblo dental 

offices, amalgam separators, and amalgam recycling. Panel members included speakers, a Pueblo dentist 

who was also a CDA board member, the City of Pueblo pretreatment coordinator, and the CDPHE Oral 

Health Program director. 

Task 2-5: Follow Up with Dentists

After the panel seminar, Tetra Tech sent the fact sheet to those dentists who did not attend the panel 

discussion and invited them to call a point of contact with any questions regarding the fact sheet or 

CDPHE’s dental mercury project. Tetra Tech also sent a letter to the meeting attendees thanking them for 

their participation in the panel discussion and offering a point of contact for them with any questions 

regarding the fact sheet, items discussed at the panel discussion meeting, or CDPHE’s dental mercury 

project. The follow-up letters also informed the dentists that they would be contacted for a follow-up 

survey for the project at a specified future time. 

Task 2-6: Write Summary Report

Tetra Tech wrote a letter report that summarizes the results of Phase 2 of the project. 

Phase 3 Procedure 

Phase 3 of this project was divided into three tasks intended to evaluate the effectiveness of the project. 

These tasks are summarized in this section. 

Task 3-1: Create Survey for Pueblo Dentists

Tetra Tech created a follow-up survey and cover letter for dentists and dental clinics in Pueblo. The 

survey required about 5 to 10 minutes for each dental office and clinic to complete and asked the 

respondents to address the following: 

• Attendance at and relevance of seminar and panel discussion 

• Receipt and relevance of fact sheet and BMP insert 

• Future planned action based on seminar, panel discussion, fact sheet, and BMP insert 

• Extent to which the outreach materials were informative and influential 

Task 3-2: Execute Follow-Up Dental Survey

Tetra Tech sent a cover letter and follow-up survey to 56 dental offices and clinics and 67 dentists in 

Pueblo. In addition, the mailing included a description regarding an offer for a free amalgam separator 

from ADA Technologies, Inc. 

Task 3-3: Write Final Pueblo Dental Mercury Summary Report

After responses from the surveys were received, Tetra Tech wrote this report, which summarizes the 

entire dental mercury P2 project with a more detailed emphasis on the follow-up survey results. 
 

7

SUMMARY OF PROJECT RESULTS

This section briefly summarizes the results of each phase of the project. More complete descriptions of 

results from Phases 1 and 2 are included in the Phase 1 and Phase 2 summary reports. Table 1 

summarizes the deliverables for the entire project. 

TABLE 1 PROJECT DELIVERABLE SUMMARY 

DELIVERABLE DELIVERY DATE RECIPIENTS 

PHASE 1 

Baseline Survey November 19, 2003 All Pueblo dentists 

Baseline Survey Summary Report February 10, 2004 CDPHE and advisory 

team 

PHASE 2 

Phase 2 Implementation Plan February 20, 2004 CDPHE and advisory 

team 

Pueblo-Specific Fact Sheet and BMP Insert May 20, 2004 All Pueblo dentists, 

CDPHE, and advisory 

team 

State-Wide Fact Sheet and BMP Insert August 6, 2004 CDPHE 

Seminar and Panel Discussion Handout 

Materials 

May 20, 2004 All Pueblo dentists 

attending seminar, 

CDPHE, and advisory 

team 

Phase 2 Summary Report June 9, 2004 CDPHE and advisory 

team 

PHASE 3 

Follow-up Survey June 25, 2004 All Pueblo dentists 

Final Project Report August 31, 2004 CDPHE 

Phase 1 Summary 

The purpose of the Phase 1 survey was to establish a baseline of information among Pueblo dentists and 

also to understand the barriers preventing BMP and BAT implementation, thereby providing a basis for 

the direction of the second phase of the project. The survey was successful in accomplishing these goals. 

The following bullets summarize the primary findings from the Phase 1 dental mercury survey; these 

findings formed the basis of the Phase 2 approach. 

• Response rate among dentists was 69 percent and among practices was 78 percent. The survey 

goal was to exceed 45 percent. 

• Most dentists use chairside traps (97.5 percent) and very few (2 percent) use amalgam separators. 

• Some dentists recycle mercury-containing waste (teeth, amalgam, amalgam capsules, screen, 

traps, and filters), but many dispose of mercury-containing waste as medical waste, in the trash, 

or through some other form of disposal. ADA recommends that all mercury-containing waste be 

recycled. 

• Based on the higher than expected response rate and responses to questions regarding assistance 

and recognition, survey results suggest a general receptiveness to outreach efforts. 

For a more complete analysis of the Phase 1 results, refer to the Phase 1 Summary Report. 
 

8

Phase 2 Summary 

After obtaining CDA support and forming the advisory team, Tetra Tech researched and wrote a 4-page 

fact sheet and BMP insert on dental mercury. Tetra Tech solicited comments and revised the fact sheet 

and BMP insert based on feedback from the advisory team. The fact sheet includes: 

• A brief overview of the project and issues associated with dental mercury and the 

environment 

• The regulatory outlook for dental mercury issues 

• A description of the performance of and vendors for mercury amalgam separators 

• Tips for mercury amalgam recycling and vendors 

In addition, the fact sheet includes an insert with a checklist of BMPs for dental mercury and a list of 

references for additional information. 

Tetra Tech also organized a seminar panel and discussion that covered (1) a project overview and CDA 

perspective, (2) the regulatory outlook, (3) amalgam separators, and (4) amalgam recycling. Tetra Tech 

used the mailing list it developed for its baseline survey of Pueblo dentists, supplemented by a list of 

dentists in Pueblo from the Southeastern Colorado Dental Society, for distribution of a flyer promoting 

the seminar and panel discussion. Tetra Tech sent the flyer to 83 dentists in 64 offices on May 7, 2004. 

The meeting was attended by 25 people (30 percent of the dentists in Pueblo) from 22 offices (34 percent 

of the offices in Pueblo). Table 2 provides a summary of the total meeting attendance. 

TABLE 2 SEMINAR AND PANEL DISCUSSION MEETING ATTENDANCE 

GROUP NUMBER OF PEOPLE 

Dentist or office representatives (dental 

offices) 

25 (22) 

Presenters and panel members 7 

Vendors 3 

Additional attendees (CDPHE, Pueblo 

City and County Health Department, 

Tetra Tech, and City of Colorado Springs) 

7 

Total Attendance 42 

Phase 3 Summary 

Tetra Tech mailed the follow-up survey to 67 dentists representing 56 practices in the Pueblo. Tetra Tech 

revised the mailing list used during Phase 1 to exclude those dentists that do not use mercury amalgam, or 

indicated in the baseline survey that they did not wish to participate in the voluntary dental mercury P2 

project. Thirty one percent of the dentists (21 out of 67 dentists) and 34 percent of the practices (19 out of 

56 practices) responded to the follow-up survey. Tetra Tech put the name of the dentist on each followup survey it sent out. To increase the response rate, Tetra Tech called each dentist that did not return the 

survey and requested that the office return the survey. Tetra Tech followed the same survey protocol and 

the same level of effort in the follow-up survey as it did for the baseline survey, but received a much 

lower response rate to the follow-up survey. Eighty one percent of the follow-up respondents also 

returned the baseline survey. 

The follow-up survey occurred within weeks of the outreach efforts (distribution of fact sheet, BMP 

insert, and holding the seminar and panel discussion); therefore, the follow up-survey was not able to 
 

9

focus on actual changes in procedures among dental offices. Instead, the follow-up survey focused on the 

value and content of the outreach materials and the overall effectiveness of the outreach effort. 

Value and Content of Outreach Materials and Seminar/Panel Discussion 

In the follow-up survey, dentists were asked to provide feedback regarding the value and content of the 

Phase 2 dental mercury fact sheet, BMP insert, and seminar and panel discussion. The dentists gave a 

yes/no response as to whether they found these specific materials and efforts to be useful and informative. 

The survey results (Figure 1) indicate that Pueblo dentists attending considered the seminar and panel 

discussion the most useful and informative. Figure 1 excludes surveys in which the dentist did not 

respond to the question, assuming that dentist did not participate in or read that particular outreach effort 

or material. 

Most dentists indicated the fact sheet 

contained an appropriate depth and range 

of information. When asked to provide 

specific feedback on the content of the fact 

sheet, one dentist responded that the fact 

sheet could be improved with additional 

information on disposal or recycling 

options for used amalgam separators. 

Most dentists indicated that the seminar 

and panel discussion presented 

information that was relevant and covered in appropriate detail. When asked to provide specific feedback 

on the content of the seminar and panel discussion, one dentist noted that a “definitive program” for 

addressing dental mercury waste was missing from the seminar discussion. This comment may reflect a 

weakness associated with the “voluntary” nature of this mercury P2 program. 

Overall Effectiveness of the Outreach Effort

The overall effectiveness of the outreach effort was gauged based on each Pueblo dentist’s perceived 

“level of knowledge” and actual or anticipated changes in behavior following the outreach effort. Note, 

the only dentist who indicated he did not feel informed on any of the topics also responded that he did not 

receive the baseline survey or the fact sheet. Records show that this dentist responded to the baseline 

survey and was mailed a copy of the fact 

sheet and BMP insert. The follow-up 

survey response by this dentist points 

out that merely mailing information to 

dentists may not be an effective form of 

communicating dental mercury BMP 

and BAT information to all dentists. 

When asked to rate how knowledgeable 

or informed they felt about dental 

mercury issues following the Phase 2 

outreach effort, most dentists indicated 

that they felt moderately informed on 

the topics of general mercury issues, 

mercury amalgam separators, and 

mercury recycling (Figure 2). 

87% 85%

100%

0%

25%

50%

75%

100%

Fact Sheet Best Management

Practice Insert

Seminar and Panel

Discussion

Figure 1 Percent Dentists Who Found Outreach Efforts 

Informative/Useful

Figure 2 Overall Knowledge of Dental Mercury Related Issues

76% 76%

52%

19% 19%

38%

0%

25%

50%

75%

100%

How informed dentists feel

about issues related to mercury

in dental offices. 

How informed dentists feel

about amalgam separators for

dental offices.

How informed dentists feel

about recycling wastes that

contain mercury in dental

offices. 

Percent of Reponses

Highly Informed

Moderately Informed

Not Informed

Desire More

Information
 

10

In the baseline survey, dentists were 

asked to rate how informed they 

were regarding BMPs and 

technologies for mercury P2 in 

dental offices. In the follow-up 

survey, this question was divided 

into three questions (See Figure 2). 

Figure 3 summarizes the change in 

response from the baseline to the 

follow-up survey. Overall, 

according to survey results (Figure 

3), through the course of the project, 

dentists indicated they increased the 

level at which they were informed 

about BMPs and technologies for mercury P2 in dental offices. 

To further assess the overall effectiveness of 

the outreach program, the survey also asked if 

anything in the fact sheet, BMP insert, or 

seminar and panel discussion would cause the 

respondents to change their mercury 

management or handling practices and 

procedures. Sixty-six percent of the 

respondents indicated they planned to change 

practices in their offices as a result of the 

outreach effort (Figure 4). 

The survey asked dentists to specify which outreach effort(s) they found to be the most influential. The 

results from this question (Figure 5) indicate that among the project outreach efforts, dentists found the 

BMP insert to be most influential. Although dentists found the fact sheet and seminar and panel 

discussion to be most informative

(Figure 1), dentists likely found the 

BMP insert to be most influential

because the insert is a user-friendly 

guide that can be posted in the dental 

office and frequently referred to by 

the dentists and staff. 

Installation of Amalgam Separators 

The survey also assessed the 

program’s overall effectiveness in 

encouraging dentists to install 

mercury amalgam separators. When 

asked whether they planned to install an amalgam separator within the next year, 19 of the 21 responding 

dentists indicated they planned to install a separator, although some dentists also responded that the cost 

and space could be barriers (one of the two dentists not planning to install an amalgam separator indicated 

he is retiring and closing his office). The level of interest in installing an amalgam separator may have 

been influenced by the free amalgam separator offer discussed in the following paragraph. 

Figure 3 Comparison of How Infomed Dentists Felt from 

Baseline to Follow-up Survey

0%

20%

40%

60%

80%

Highly informed Moderately

Informed

Not informed Desire More

Information

Percent of Respondents

Baseline

Follow-up (average)

Figure 4 Repondents Plan to Change Practices in 

Office as a Result of Outreach Efforts

14

66%

2

10%

1

5%

4

19%

Yes

No

Somewhat

No Response

33% 33%

48%

43%

0%

20%

40%

60%

Percent of Responses

Baseline Surevey Fact Sheet BMP Insert Seminar and Panel

Discussion

Outreach Materials

Figure 5 Most Influential Outreach Materials 
 

11

During Phase 2 of this project, ADA Technologies, Inc., a manufacturer of amalgam separators and one 

of the presenters at the seminar and panel discussion, offered several previously used (tested) amalgam 

separators to Pueblo dentists free of charge. In the follow-up survey, dentists were asked to indicate their 

interest in obtaining a free amalgam separator from ADA Technologies, Inc. The survey results showed 

that 86 percent (18 out of 21) 

dentists that responded to the survey 

indicated an interest in obtaining a 

free amalgam separator (the 

remaining 3 dentists did not respond 

to the question). Seminar 

attendance appeared to improve the 

interest in the offer. Forty-four 

Pueblo dentists did not respond to 

the survey or indicate interest in the 

free amalgam separator offer. 

Figure 6 summarizes Pueblo 

dentists’ interest in the free 

amalgam separator offer. 

Change in Recycling Practices 

Thirty-three percent of the dentists responding to the survey indicated they were already recycling 

amalgam waste, while 57 percent indicated that they planned to begin recycling amalgam waste (Two 

respondents did not answer this question). Those dentists planning to recycle amalgam waste indicated 

that the following types of materials would be recycled: 

• contact amalgam 

• non-contact amalgam 

• extracted teeth 

• empty amalgam 

capsules 

• elemental mercury 

• screens 

• traps 

• filters 

Transferability Statewide

Finally, the survey assessed the transferability of the outreach effort statewide. A large majority of the 

dentists (86 percent) responded that this outreach effort would be beneficial in other Colorado 

communities. Two dentists responded that they did not think it would be useful to dental offices in other 

areas of Colorado, but did not provide a reason and one dentist did not respond to the question. 

Figure 6 Dentists' Interest in Free Amalgam Separator 

Offer

7

10%

11

16%

3

4%

2

3%

44

67%

Interested, Responded to Follow-Up

Survey, and Attended Seminar

Interested, Responded to Follow-Up

Survey, and Did Not Attend Seminar

Did Not Respond on Follow-Up Survey

Question about Free Amalgam Separator

Interested but Did Not Respond to

Follow-Up Survey

Did Not Indicate Interest or Respond to

Survey
 

12

CONCLUSIONS 

This section summarizes the conclusions of the Pueblo dental mercury P2 project. 

Use of Surveys for Feedback 

Through this Pueblo dental mercury P2 project, Pueblo dentists were sent both a baseline and follow-up 

survey. The baseline survey was used to evaluate dentists’ current awareness of mercury issues, and to 

identify the barriers to implementing mercury BMPs and BATs in dental offices. The follow-up was used 

to evaluate the effectiveness of the outreach project. The following bullets summarize conclusions about 

the use of surveys for feedback. 

• The project surveys were useful tools for obtaining information from dentists to direct the project 

implementation and to assess the project effectiveness. 

• Survey response rates increased when Tetra Tech called each dental office to encourage survey 

response. Other efforts or incentives might further increase survey response rates. 

• Although the same survey protocol and same number of hours was used to follow up with dentists 

after the survey mailings, the follow-up survey response was significantly lower than the baseline 

survey response. In the baseline survey, 41 of 59 dentists (69 percent) responded, while in the 

follow-up survey 21 of 67 dentists (31 percent) responded. The reason for the decrease in 

response rate is unclear. 

• In order to obtain measurable results from the project, a longer timeline after the completion of 

project implementation is recommended. The follow-up survey was conducted within weeks of 

the date when dentists received the fact sheet and attended the seminar and panel discussion. The 

program effectiveness, in terms of implementation of BMPs and installation of amalgam 

separators, would be better assessed through a follow-up survey conducted at least 6 months to 

1.5 years after program implementation. 

Value, Content, and Effectiveness of Outreach Materials and Seminar/Panel Discussion 

Pueblo dentists were given a dental mercury fact sheet and BMP insert, and, were offered the opportunity 

to attend a dental mercury seminar and panel discussion. The following bullets summarize conclusions 

about the value, content, and effectiveness of the outreach effort. 

• Most dentists found the fact sheet, BMP insert, seminar and panel discussion to be useful and 

informative. The seminar and panel discussion were considered the most informative outreach 

components, while the BMP insert was considered the most influential outreach component. 

• One dentist indicated that the seminar and panel discussion lacked a “definitive program,” which 

may reflect a weakness associated with the “voluntary” nature of this mercury reduction program. 

• The level to which dentists felt moderately to highly informed increased up to 16 percent during 

the course of the project. 

• More than 70 percent of the Pueblo dentists responding to the follow-up survey indicated that 

they planned to change their behavior with respect to handing mercury amalgam waste as a result 

of the outreach efforts. 

• Ninety percent of the Pueblo dentists responding to the follow-up survey indicated that they are 

now, or will be, recycling mercury-containing amalgam and waste. This compares to the baseline 

survey results where only 46 percent of the respondents reported recycling scrap amalgam and 

only up to 12 percent reported recycling other mercury containing wastes. 

• Eighty-six percent of the Pueblo dentists that responded to the survey indicated an interest in 

obtaining a free amalgam separator. Two additional Pueblo dentists that did not respond to the 

survey requested a free amalgam separator. This compares to the baseline survey where a total of 

only four dentists indicated that they would install an amalgam separator if it was provided free of 

charge. 
 

13

Transferability of Outreach Effort to Other Colorado Communities 

Other communities may benefit from the outreach materials and other tools developed during the 

voluntary dental mercury P2 project in Pueblo. Most directly transferable is the fact sheet and BMP insert 

which Tetra Tech wrote in a manner that it is applicable to dentists state-wide. However, many other 

materials and tools could be used “as-is” or slightly modified to fit the needs of other Colorado 

communities. These items include: 

• Baseline cover letter and survey 

• Baseline summary report which examines the data from the baseline survey results 

• Seminar and panel discussion announcement flyers 

• Seminar and panel discussion slides and handout materials 

• Follow-up cover letter and survey 

• Final report which examines the date from the follow-up survey results 

Value of the Voluntary Approach 

The results of the Pueblo Dental Mercury P2 project provide an indication of the value and effectiveness 

of voluntary programs, as opposed to regulatory programs, in effecting changes in behavior among 

dentists. In the Phase 1 survey, 46 percent of the Pueblo dentists stated that that a “legal requirement” 

would be the primary motivation for purchasing and installing a mercury amalgam separator, and only 4 

dentists indicated that they would install an amalgam separator if it was provided free of charge. 

However, at the conclusion of the Phase 3 outreach effort, a total of 20 Pueblo dentists indicated that they 

were interested in obtaining and installing a free amalgam separator. Clearly, a law requiring the 

installation of amalgam separators would increase the number of amalgam separators installed. However, 

working with dentists on voluntary basis may eliminate the need to regulate amalgam separator 

installation. Further, if regulations do become necessary, voluntary start-up programs may enable dentists 

to play a more informed and significant role in the regulatory process.