4 - Final recommendation on Mercury limits in the Industrial Pretreatment Program, including propose
C I T Y O F B O U L D E R
WATER RESOURCES ADVISORY BOARD
AGENDA ITEM
MEETING DATE: February 26, 2007
AGENDA TITLE:
Final recommendation on Mercury limitsin the Industrial
Pretreatment Program, including the proposed rules to require the installation of amalgam
separators in some dental offices.
PRESENTER/S:
Ridge Dorsey- Pretreatment Program Specialist
Megan Monroe- Pretreatment Program Field Specialist
Bret Linenfelser – Water Quality Coordinator
EXECUTIVE SUMMARY:
The pretreatment program staff requests a final recommendation by the Water Resources
Advisory Board (WRAB) to the City Manager for approval of Rules Concerning
Treatment and Disposal of Amalgam Wastewater within the cityof Boulder. (Appendix
1). These rules are issued pursuant to Sections 11-1-3 and 11-3-24, B.R.C. 1981.
In 2003, the city of Boulder’s wastewater treatment plant was issued a Colorado
Discharge Permit System (CDPS) permit with an effluent mercury standard of 12
th
nanograms/liter. Wastewater effluent samples collected at the 75 Street treatment plant
are approaching, and in some cases have exceeded, the limits established for discharges
to Boulder Creek. Studies have shown that dental offices are one of the largest
contributors of mercury to the wastewater stream due to discharges containing dental
amalgam. Best available technology (use of amalgam separators) has been tested by
numerous organizations, including the American Dental Association and has shown the
capability of capturing up to 99 percent of mercury released from dental practices.
Pretreatment staff has worked with local dentists to review a draft rule that will require
the installation of mercury removal treatment equipment for dental wastewater called
amalgam separators. The rule also requires dental offices to follow best management
practices regarding the handling and disposal of dental amalgam. On Jan. 25, 2007,
pretreatment staff held a public meeting to present and discuss the proposed regulations
for dental practices. Staff also mailed the proposed rule to local dental offices, and
posted the rule on the city of Boulder utilities internet site.
AGENDA ITEM# IVPAGE
1
Comments regarding the draft rule have been few and the local dental association
supports the rule. Minor suggested changes to the wording of the draft rule have been
incorporated into the draft.
Please refer to:
Appendix 1 - Draft Rule
Appendix 2 - Program Overview
Appendix 3 - Frequently Asked Questions, for additional background information
Fiscal Impacts:
Budgetary:
Additional funds are not being requested at this time.
Staff Time:
Existing staff time is being utilized for this project.
Other Impacts:
Dental offices will be required to purchase, install, and maintain
wastewater treatment equipment called amalgam separators. This will be an
ongoing cost. Costs will vary depending on the size of the dental practice and
unit of choice. In general, typical costs range from $300-$2,000 in purchase,
approximately $200 for installation and between $75-$750 from annual
maintenance and waste disposal (US EPA Region 5). Please refer to Appendix 3
for additional cost charts.
Other Board and Commission feedback:
No feedback from other Boards and
Commissions has been requested
Public feedback:
The draft rules were mailed to all dental offices within the city of
Boulder and posted on the Utilities Web site. On Jan. 25, 2007, a meeting was held in
which proposed regulations were explained, and information was provided by vendors
and manufacturers on separator technology. General comments were accepted until Feb.
8, 2007.
The meeting was attended by ten local dentists, equipment vendors, Partners for a Clean
Environment (PACE) representative and city staff. Lisa Kalfas, a dentist who has a
separator in her office, spoke favorably about the program. Several of the dentists spoke
with equipment vendors, as well as city staff. Dr. Heidi Winquist, president of the
Boulder County Dental Society (BCDS), stated that she was representing about 250 area
dentists and that the “Boulder Dental Society fully supports the city of Boulder.” She
also stated that she would contact her society’s membership to recommend separators.
If proposed rules are accepted, a formal30-day comment period will allow additional
feedback from the dental community.
Staff recommendation:
In order to reduce the mercury discharged to the wastewater treatment plant and to
comply with the state’s limit for clean waterways, the city of Boulder’s pretreatment staff
is recommending regulation changes that will affect how dental amalgam is managed by
AGENDA ITEM# IVPAGE
2
dental practices. Please refer to Appendix 1 for the complete draft rule. In summary,
regulations would include:
1)The mandatory installation of an International Organization for
Standardization (ISO)11143 approved amalgam separator.
2)Implementation of best management practices, including the proper
management of chair-side filters and traps, as well as the proper handling and
recycling of amalgam waste annually.
3)Annual self-certification of best management practices and maintenance
records.
Analysis:
Please refer to Appendix 2 for Program Overview.
Matrix of options:
1.Require Rule as written and suggested by pretreatment staff. The Pretreatment
staff believes that the use of best available technology and management practices,
as outlined in proposed rule, will significantly reduce the dental mercury
contribution.
2.Continue voluntary program, focus funds on further outreach and education
regarding technology available, but do not approve the draft Rule.
3.Stop education efforts for the voluntary program and do not approve the draft
Rules. Continue monitoring of mercury levels until after the treatment plant
upgrade.
AGENDA ITEM# IVPAGE
3
Appendix 1 – WRAB February 26, 2007
DRAFT
Rules Concerning Treatment and Disposal of Amalgam Wastewater within the city of
Boulder
Part #1Purpose and Applicability
It is the intent of these rules to protect the city’s wastewater treatmentsystem and Boulder Creek
from the introduction of excessive amounts of mercury; to protect humanhealth, aquatic life and
wildlife; to comply with the state’s limit for clean waterways; and to meet the city permit
requirements for the quantity of mercury discharged to Boulder Creek.
Since 2003, when the city of Boulder was issued a CDPS permit with an effluent mercury
standard of 12.0 ng/L, the wastewater treatment plant has had concerns for compliance with this
limit. Concurrently with the permit changes, the EPA Region VIII began to develop focused
policy guidance for mercury control to wastewater treatment plants. It is anticipated that EPA
will require further pretreatment program controls for mercury.
Once in the environment, mercury can be converted to its most toxic form, methylmercury.
Methylmercury is persistent and bio-accumulates within the environment. It is a neurotoxin, and
exposure can cause damage to the development and functioning of the nervous system as well as
various environmental concerns.
Among sources of mercury in the wastewater, dental amalgam is an avoidable pollutant. Dental
practices, through the proper technology, have the means to dramatically minimize the amount of
mercury discharged. Through the installation of an International Organization for
Standardization (ISO) approved separator and use of best management practices, dental practices
can capture up to 99.9 percent of their amalgam waste.
To effectively address this issue, the city has developed these Rules Concerning Treatment and
Disposal of Amalgam Wastewater in support of Title 11, Chapter 3, B.R.C. 1981.
(a) Purpose. This rule establishes requirements for controlling the discharge and recycling of
amalgam wastewater from dental practices. The purpose of the amalgam wastewater rules is to
reduce mercury in wastewater by preventing its release from the source through proper handling
and the use of filters and separators in dental practices. The objectives of this rule are:
(1) to reduce the amount of mercury discharged into Boulder’s wastewater collection system.
(2) to meet city permit requirements and remain in compliance with the state’s limit for clean
waterways.
(3) to protect human health and aquatic life through protecting the city’s water supplies.
(4) to establish administrative review procedures and reporting requirements.
(5) to establish enforcement procedures for violations of any part or requirement of this rule.
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(b) Applicability. The provisions of this rule are applicable to all dental practices located within
the municipal boundaries of the city of Boulder or within the wastewater treatment plant service
area that discharge wastewater from the placement or removal of amalgam containing mercury.
(1) Waivers. Waivers will be granted to dental practices in which no dentist places or removes
amalgams containing mercury and / or teeth containing mercury amalgams. A written request
for a waiver must be sent to the City of Boulder’s Industrial Pretreatment Program.
Part #2 Authority
These rules are issued pursuant to Sections 11-1-3 and 11-3-24, B.R.C. 1981.
Part #3Definitions and Abbreviations
The definitions included here are specific to this rule. Definitions of other terms used in this rule
are the same as those contained in Section 11-3-3, B.R.C. 1981.
“Amalgam,” for the purpose of this rule, meansany mixture or blending of mercury with another
metal or with an alloy used in dental applications.
“Amalgam separators” means a type of wastewater treatment equipment that is designed to
remove amalgam particles and dissolved mercury from the wastewater discharged by dental
practices.
“Amalgam waste” includes any waste containing mercury or residues from the preparation of the
amalgam. This includes any waste generated or collected by chair-side traps, screens, filters,
vacuum system filters, amalgam separators, elemental mercury, and amalgam capsules.
a. “Non-contact amalgam” includes scrap or excess amalgam after procedure is complete, as well
as the remaining amalgam capsule.
b. “Contact amalgam” means scrap that has come into contact with patient or body fluids.
Examples include: extracted teeth and scrap collected in chair-side traps and vacuumpump
filters.
“Best Management Practices” (BMPs) means a set of operational standards designed to minimize
the environmental impact and human exposure to mercury.
“Dental Practice,” as use in thisrule, means any dental facility that discharges wastewater from
the placement or removal of amalgam containing mercury.
“Exempt Dental Practice” means any dental facility in which no dentist places or removes
amalgams containing mercury and / or teeth containing mercury amalgams.
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Abbreviations: For the purposes of this rule, the following abbreviations shall have the meanings
designated in this rule.
BMPs: Best Management Practices
CDPS: Colorado Discharge Permit System
ISO: International Organization for Standardization
Ng/L: Nanograms (Ng) per Liter (L)
Part #4 Amalgam Separators and Best Management Practices
(a) Requirements. All dental practices that discharge wastewater generated from the placement
or removal of amalgam are required to install an amalgam separator in accordance with the
following guidelines and to implement the following BMPs.
(1) Dental Practice. Within one year of the effective date of this rule, all dental practices shall
have installed and are required to maintain and utilize an approved amalgam separator according
to the requirements contained in this rule. Withinsix months of the effective date of this rule, all
dental practices shall be required to implement and certify the BMPs and, thereafter, recertify
annually according to the requirements contained in this rule.
(2) Exempt Dental Practice. Waivers will be granted to dental practices in which no dentist
places or removes amalgams containing mercury and / or teeth containing mercury amalgams.A
written request for a waiver must be sent to the City of Boulder’s Industrial Pretreatment
Program within six months of the effective date of this rule.
(b) Amalgam separators. Amalgam separators shall be installed in all dental practices, except in
the case of exempt dental practices. All amalgam separators shall meet the following criteria:
(1) Amalgam separator design. The amalgam separator shall be ISO 11143 certified and shall be
designed and approved for a flow rate capable of handling the maximum volume discharged
from the dental practice it serves.
a. The amalgam separator must be tested according to the most current ISO 11143 standard.
Each dental practice should select a separator with the highest efficiency level attainable in their
working conditions.
b. If ISO increases the acceptable standard, the dental practice must comply with the new
standard within five years.
(2) Installation. The amalgam separator shall be installed so that all amalgam-contaminated
wastewater will pass through the unit before being discharged.
(3) Inspection and maintenance. Each dental practice shall be responsible for inspecting and
maintaining the amalgam separator.
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(4) Disposal. Waste removed from the amalgamseparator shall be collected and handled in
accordance with the manufacturer’s instructions and as described below.
(c) Best Management Practices. BMPs shall be implemented, certified within six months of
effective date, and recertified each calendar yearby February 15th. Each dental practice shall
comply with the following BMPs:
(1) Equipment. The dental practice shall ensure that all dental chairs are equipped with chair-
side traps and that all vacuum pumps are equipped with traps and filters. All equipment shall be
cleaned, disposed of, and maintained in accordance with the manufacturer’s instructions.
(2) Clean-up procedures. Each dental practice shall use non-chlorine or non-oxidizing
disinfectants and neutral cleaners. When cleaningfilters or collecting scrap amalgam, the dental
practice shall not rinse filters or traps over sinks or drains. All water containing amalgam waste
must be washed through amalgam separator lines.
(3) Recycling. The dental practice shall recycle all bulk mercury and all amalgam waste.
(4) Salvaging. All contact and non-contact scrap amalgam shall be salvaged and stored in
structurally sound, tightly closed and appropriately labeled containers.
(5) Disposal. The dental practice shall never dispose of amalgam waste in the garbage,
infectious waste or biohazard containers. All amalgam waste shall be transferred to an offsite
recycling facility for recycling of mercury on an annual basis.
(6) Amalgam selection. The dental practice shall use only pre-capsulated, single-use amalgam
and shall stock a variety of sizes in order to minimize waste.
Part #5 Record Keeping and Reporting
(a) Record keeping. The dental practice shall maintain records of amalgam disposal. These
records shall include the date, the name and address of the facility to which any waste amalgam
is shipped, and the amount shipped. The dental practice shall also maintain records of all
maintenance and service completed on the amalgam separator. All records shall be kept on site
for a minimum of three years and shall be madeavailable to the City of Boulder on request.
(b) Reporting. Within one year, the dental practice shall submit a certification form of
compliance, attained from the city of Boulder. The form shall include:
(1) Amalgam separator compliance. To show compliance with the amalgam separator
requirement, the dental practice shall include the following information: the manufacturer and
model name of the separator, the date of installation, the name of the company that installed the
unit, and the name and address of the recycler used.
(2) BMPs certification compliance. To show compliance with the BMPs requirement, the dental
practice shall sign a self-certification of the BMPs implemented at the dental practice. This form
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shall be signed by all dentists practicing at a given location. The dental practice shall recertify
annually by February 15th and shall submit the formwith any changes made at the dental
practice to:
Pretreatment Specialist
Water Quality and Environmental Services
City of Boulder
4049 N. 75th Street
Boulder, Colorado 80301
Part #6 Administrative – Recovery and / or Remedies
(a) Dental practices that handle amalgam and do not implement BMPs and / or install an
amalgam separator will be subjected to enforcement. Names and offices will be published in the
newspaper displayed as “NOTICE OF NONCOMPLIANCE”. Offices not completing
compliance forms will likely be inspected by a City of Boulder employee. Additional
enforcement options include notices of violation, fines, and imprisonment.
(b) Remedies Nonexclusive. The remedies provided for in this rule are not exclusive. The City
may take any, all, or any combination of actions against a noncompliantdental practice. The
City may take other action against any dental practice when the circumstances warrant. Further,
the City is empowered to take more than one enforcement action against any noncompliant
dental practice.
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Appendix 2 – WRAB February26,2007
City of Boulder Dental Wastewater Mercury Reduction –Program Overview
In 2003, the city of Boulder was issued a Colorado Discharge Permit System permit with an effluent
mercury standard of 12 nanograms per liter (ng/L).The advent of this limit required additional focus on
mercury from the pretreatment staff, wastewater staff and laboratory personnel.Despite such efforts,
th
effluent samples collected at the wastewater treatment plant (located at 4049 75 Street) are approaching,
and in some cases, have exceeded the limits established for Boulder Creek. Since May 2004, the WWTP
has had four excursions with levels as high as 25.9 ng/L (Table 1).
Table 1: Effluent mercury levels collected at the WWTP 3/8/2004-7/24/2006
SAMPLEDATERESULT(ng/L)
3/8/200410.8
16.3
5/24/2004
6/29/20047.1
7/28/20045
9/29/20045.8
10/27/20045.2
11/17/200410.4
12/27/200410.1
2/23/20059.6
3/30/20058.9
4/27/20056.8
5/24/2005 25.9
7/12/200510.8
8/31/200510.1
9/21/20058.5
10/18/20054.7
11/21/200513.4
1/25/200611.2
2/21/20069.6
19.7
3/17/2006
4/17/20064.2
7/24/200610.2
Concurrentlywith the permit changes, the EPA Region VIII began to develop focused policyguidance for
mercury control to wastewater treatment plants (WWTPs). While this policyguidance remains in draft
form, the essential need to controlmercurydischarges to wastewater treatment plants cannot be set aside.
On a national level, the EPA has recently lowered the maximum level of allowable mercury.It is
probable that as city permits are renewed, additional utilities will be forced to regulate mercury levels.
Among sources of mercury, dental amalgam is an avoidable pollutant. The amalgam or mixture of metals
includes copper, tin, silver, zinc and is roughly 50 percent mercury.Disposal of amalgamcontaining
mercury is problematic as it cannot be incinerated and should notbe flushed down the drain. Once in the
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Appendix 2 – WRAB February26,2007
environment, mercury can be converted to its most toxic form,methyl-mercury. Methyl-mercury is
persistent and bio-accumulates within the environment. Exposure can cause damage to the development
and functioning of the nervous system as well as various environmental concerns.
Another complication is that mercury is not degraded or destroyedby the treatment process; most of the
mercury will settle in bio-solids or will be discharged into streams. Furthermore, sewer sludge with a
high concentration of mercury is classified as a toxic wasteand cannot be sold or land applied. Mercury
reduction in wastewater can be attainable through proper handling and the use of filters and separators in
dental offices. Therefore, the best way to reduce mercury is by preventing its release from the source.
The Colorado Department of Public Health and Environment (CDPHE) explained that the point is not
how much dental offices contribute to the source of mercury in lakes and streams, but that dental offices
have the means to dramatically minimize the amount of mercury discharged (CDPHE Dental Mercury
and the Environment Fact Sheet 2004).In addition, it has been stated that the installation of an ISO-
approved separator and best management practices (BMPs) including proper disposal of amalgam waste
from traps, filters and separators, dental offices can capture up to 99.9 percent of their amalgam waste
(PACE; Amalgam Separator Resource Sheet).
What are the options?
As lower mercury limits are set, more jurisdictions have established mercury reduction programs.
Nationally,there are numerous voluntary programs and regulatoryprogramsexist in CA, CO, MN, OR,
WA, WI and across the New England states. Unfortunately, little success has come out of voluntary
programs. A report by King County, WA reported that during a seven-year period (1994-2000), dental
offices wereencouraged to install separators with cash incentives.The county spent an estimated
$250,000 on the outreach and incentives; however, after seven years, only three percent (24 of 900) of the
offices had installed a separator. It was not until the county warned that mercurylevels would be
enforced that 80 percent of dental offices installed separators.
The city of Boulder also has a history of working to establish a voluntary program to minimize
the environmental impact by dental offices. In 1997, the Dental Waste Pollution Prevention
Project was established with funds awarded from the CDPHE.This grant provided funds for
dental office monitoring as well as the development and printing of best management outreach
materials. The grant also initiated cooperative efforts between the city of Boulder and Partners
for a Clean Environment (PACE). PACE developed a voluntary dental certification program and
has assisted 13 of approximately 91 dentists within Boulder with the installation of an amalgam
separator. Those offices that have installed separators may view it as responsible business
protocol and additional offices within Boulder are waiting for the final catalyst to move forward
with the installation of a separator.
An arduous alternative to requiring installation would include setting and monitoring wastewater
mercury discharges from dental offices. Monitoring discharges from dental offices can be
difficult as the levels tend to fluctuate daily if not hourly. It is also logistically difficult to tap
into the waste stream without altering the vacuum system and financially expensive as samples
are most often sent off-site for analysis.
The American Dental Association(ADA) has suggested BMPs, stating “Amalgam should not be
disposed of in the garbage, infectious waste ‘red bag’ or sharps containers. Amalgam should
also not be rinsed down the drain.”Since 1984, the ADA has recommended the use of pre-
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Appendix 2 – WRAB February26,2007
capsulated amalgam alloy only. Most mercury reduction programs that require the installation of
amalgam separators also require the implementation of BMPs.
Consequently, in order to reduce the mercury discharged and to comply with the state’s limit for
clean waterways, the city of Boulder is suggesting a mandatory implementation of BMPs and
installation of an amalgam ISO 11143 certified separator in all dental practices handling
mercury.
New regulations will be applicable to all dentalpractices that generate or discharge wastewater
from amalgam-related processes. Exclusions may include periodontists, orthodontists or oral
surgeons. Waivers will be accepted in writing and granted to any practice in which no dentist
removes or places amalgam and/or teeth containing amalgam.
What have other programs done?
Mercury programs are well established on the East and West coasts and are becoming more
common in the Midwest and Western states. Within Colorado, Ft. Collins is the first regulatory
program with additional voluntary programs across the state. Although Ft. Collins did not have a
mercury discharge limit, the concentration of mercury exceeded the manageable head-works
load. Effective July 1, 2005, Ft. Collins required basic BMPs as well as the installation of an
amalgam separator (with an efficiency of 95 percent) in any office removing two or more
amalgams in one year. The response within the dental community was fairly positive with few
offices opposing the regulations, some extensions where made for offices that were unable to
meet the time restraints. Ft. Collins has measured an approximate 30 percent reduction in
mercury in wastewater.
Information about amalgam separators
A. Separator Technology and Efficiency levels - ISO 11143: International Organization for
Standardization (ISO)
Using physical and chemical processes such as filtration, sedimentation, centrifugation and ion
exchange, amalgam separators can remove particulate mercury matter as small as 100m in
diameter. However, it is important to note that not all separators are equally effective at the
same flow rate; efficiencies are determined for a specific flow rate at which that unit can operate.
Tested flow rates vary from 1 liter per minute to 4 liters per minute. Dental practices must select
a separator that has been tested and approved at a flow that is comparable to their maximum flow
rate discharged.
Currently, the ISO 11143:1999 standard guarantees efficiencies of at least 95 percent removal.
This ISO 11143 standard has served as a benchmark; however, some states have raised the bar
by requiring as high as a 99 percent removal.For the most part, utilities requiring higher
standards, work under large departments, with the staff required to monitor practices and
manufacturers. Current programs are in: VT, CT, Milwaukee, San Francisco, Ft. Collins at 95
percent; MA, ME at 98 percent; MN, NY at 99 percent. It should be noted that the ISO testing
protocol is being re-evaluated which may lead to higher testing standards including maximum
flow capacity. New protocol is expected to be released in August 2007.
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Appendix 2 – WRAB February26,2007
The requirement of efficiency standards to exceed that set by the ISO 11143 reflects the current
industry trends and the advancement of best available technology. Furthermore, with mercury
coming to the forefront of environmental issues and growing public concern, more pressure has
been placed on utilities to achieve the highest standard possible.Although the city of Boulder is
proposing the requirement of separators with an efficiency of at least 95 percent, it should be
suggested that each dental practice selects a separator with the highest efficiency level attainable
in their working conditions.
B. Testing and Certification:
In order to assure that manufacturers are complying with the ISO standards and their products
are satisfactory, a few programs require additional accreditations from certified laboratories and
certification bodies. Additional test and certifications are initiated and paid for by the
manufactures; this assures the highest quality and releases the governing body of the
responsibility of such quality assessments. Certification programs review testing reports,
examine design changes as well as conduct marketsurveillance (inspecting products on market)
and conduct periodic visits to the manufacturer in order to ensure that models produced are those
that were originally tested. Currently, the two certification bodies that are widely accepted are
RWTUV (Germany) and SP Swedish National Testing and Research Institute (Sweden).
Although the city of Boulder will not be requiring additional testing, we are compiling a list of
separators that meet the ISO standards and will note those that are tested and certified; separators
on the list have met the highest quality standard and testing available. It is important to note that
the list will not be all-inclusive and should be used as a guide. The city of Boulder does not
endorse any manufacturer and will not be responsible for faulty equipment or improper
installation. Ultimately, it is thedecision of the dental practicewhich unit will be installed.
C. Cost of Separators:
Table of estimated annual cost for amalgam separators: PACE Resource Sheet 2006
Small(1-4Medium (5-12Large (+12 chairs)
chairs)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
Cost of amalgam separators can vary, but are relative to the size of the dental operation. Prices
listed on the previous table are based on information gathered by PACE from manufacturersin
September 2005. Maintenance and replacement costs are averaged to annual estimates and
replacement costs includes the cost of recycling services and shipping. It is important for each
dental practice to review information on manufacturers and vendors of specific separators. In
many cases, the vendors will arrange yearly maintenance and waste removal.
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Appendix 2 – WRAB February26,2007
Best Management Practices (BMPs):
BMPs are designed to protect and assist dental practices with the management of amalgam as
well as minimize exposure. Under the proposed regulations, dental officeswill certify that their
practice is complying with BMPs within six months of the effective regulations and will then be
required to renew the certification annually.
Non-Compliance:
Dental practices who handle amalgam and who do not implement BMPs and/or install an
amalgam separator will be subjected to enforcement. Names and offices will be published in the
newspaper displayed as “NOTICE OF NONCOMPLIANCE”. Offices not completing
compliance forms will likely be inspected by a city of Boulder employee. Additional
enforcement options include notices of violation, fines and imprisonment.
- Criteria from DRAFT rule-
Amalgam Separators and Best Management Practices
(a) Requirements. All dental practices that discharge wastewater generated from the placement
or removal of amalgam are required to install an amalgam separator in accordance with the
following guidelines and to implement the following BMPs.
(1) Dental Practice. Within one year of the effective date of this rule, all dental practices shall
have installed and are required to maintain and utilize an approved amalgam separator according
to the requirements contained in this rule. Withinsix months of the effective date of this rule, all
dental practices shall be required to implement and certify the BMPs and to recertify them
annually according to the requirements contained in this rule.
(2) Exempt Dental Practice. Waivers will be granted to dental practices in which no dentist
places or removes amalgams containing mercury and / or teeth containing mercury amalgams.A
written request for a waiver must be sent to the City of Boulder’s Industrial Pretreatment
Program within six months of the effective date of this rule.
(b) Amalgam separators. Amalgam separators shallbe installed in all dental practices, except in
the case of exempt dental practices. All amalgam separators shall meet the following criteria:
(1) Amalgam separator design. The amalgam separator shall be ISO 11143 certified and shall be
designed and approved for a flow rate capable of handling the maximum volume discharged
from the dental practice it serves.
a. The amalgam separator must be tested according to the most current ISO 11143 standard.
Each dental practice should select a separator with the highest efficiency level attainable in their
working conditions.
b. If ISO increases the acceptable standard, the dental practice must comply with the new
standard within five years.
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Appendix 2 – WRAB February26,2007
(2) Installation. The amalgam separator shall be installed so that all amalgam-contaminated
wastewater will pass through the unit before being discharged.
(3) Inspection and maintenance. Each dental practice shall be responsible for inspecting and
maintaining the amalgam separator.
(4) Disposal. Waste removed from the amalgamseparator shall be collected and handled in
accordance with the manufacturer’s instructions and as described below.
(c) Best Management Practices. BMPs shall be implemented, certified, and recertified each
calendar year by February 15th. Each dental practice shall comply with the following BMPs:
(1) Equipment. The dental practice shall ensure that all dental chairs are equipped with chair-
side traps and that all vacuum pumps are equipped with traps and filters. All equipment shall be
cleaned and maintained in accordance with the manufacturer’s instructions.
(2) Clean-up procedures. Each dental practice shall use non-chlorine or non-oxidizing
disinfectants and neutral cleaners. When cleaningfilters or collecting scrap amalgam, the dental
practice shall not rinse filters or traps over sinks or drains.
(3) Recycling. The dental practice shall recycle all bulk mercury and all amalgam waste.
(4) Salvaging. All contact and non-contact scrap amalgam should be salvaged and stored
in structurally sound, tightly closed and appropriately labeled containers.
(5) Disposal. The dental practice shall never dispose of amalgam waste in the garbage,
infectious waste or biohazard containers. All amalgam waste shall be transferred to an offsite
recycling facility for recycling of mercury annually.
(6) Amalgam selection. The dental practice shall use only pre-capsulated, single-use amalgam
and shall stock a variety of sizes in order to minimize waste. The dental practice shall also
substitute amalgamwhenever possible and provide health information about amalgam containing
mercury and possible alternatives.
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Appendix #3
February 26, 2007
City of Boulder
Dental Mercury Reduction Program
Frequently Asked Questions
Why does the city have to implement new regulations now?
The city of Boulder was issued a revised permit in 2003. This required strict low-level mercury
sampling and limits the amount of mercury discharged from the wastewater treatment plant
(WWTP) to 12ng/L. Since 2003, effluent samples have shown levels as high as 25.7ng/L.
Furthermore, in Colorado, state agencies regulate wastewater treatment plants, which in turn have
the authority to regulate business and industry that discharge wastewater upstream of the plant.
The goal of the Pretreatment program is to be in compliance 100% of the time and protect the
wastewater utility which, in turn, protects the environment.
Who will the regulations affect?
Proposed regulations will be applicable to all dental practices within the city of Boulder that
discharge wastewater from the placement or removal of amalgam containing mercury or teeth
contain amalgam.
Waivers will be granted to dental practices in which no dentist places or removes amalgam
containing mercury and/or teeth containing mercury amalgams. A written request for a waiver
th
must be sent to the city of Boulder’s Industrial Pretreatment Program, 4049 N. 75 St., Boulder,
CO 80301.
Exclusionsmay include: periodontists, orthodontists, endodontics, and oral surgeons.
Why is the city looking at mandating instead of a voluntary program?
In 1997, the city of Boulder started working with dentists who wanted to voluntarily reduce their
mercury discharge. With funds from the Colorado Department of Public Health and Environment
(CDPHE), the city of Boulder developed outreach material and created the Dental Waste
Pollution Prevention Program.
In addition, the city of Boulder works alongside Partners for a Clean Environment (PACE) to
educate dental practices on Best Management Practices (BMPs) and amalgam separators.
Currently, 13 out of 91 dental offices have voluntarily installed an amalgam separator.
How is the mercury level in wastewater measured?
Mercury in wastewater is measured following U.S. Environmental Protection Agency (EPA)
protocols. Samples for mercury at the wastewater plant are collected utilizing "clean sampling
techniques" to prevent or minimize sample contamination. Analysis for mercury follows EPA
method 1631 for low level detection. Method 1631 can analyze mercury to as low as 2.5
nanograms per liter (ng/l). Analyses of samples with higher mercury concentrations utilize EPA
method 245.1.
What level is determined to be a significant level of contamination?
The city of Boulder wastewater treatment plant discharges treated effluent to Boulder Creek.
This discharge is regulated by a state issued Colorado Discharge Permit System (CDPS) permit.
The limit for mercury released to the creek is 12 ng/l. Mercury monitoring over the last 3 years
has shown a data range of 4.2 ng/l to 25.9 ng/l.
Appendix #3
February 26, 2007
What is the American Dental Association’s stance on recycling and amalgam separators?
Since the early 1980's, the ADA has advocated for the proper handling and recycling of amalgam
1
tooth-filling wastes from dental offices.
In February 2004, the ADA published Best Management Practices (BMP) for Amalgam Waste.
In this document, the ADA strongly recommended recycling as a BMP for dental offices.
Furthermore, the ADA states, “amalgam should not be disposed of in the garbage, infectious
2
waste, “red-bag” waste or the sharps container…”
Do other utilities have mercury programs?
Across the nation, state and local governments are developing programs and regulations that
address mercury, including dental mercury. States such as Maine, New Hampshire, New York,
Connecticut and Vermont and cities like Seattle, WA, Minneapolis, MN, Milwaukee, WI,
Wichita, KS, and Fort Collins, CO all have regulations concerning amalgam separators.
Isn’t mercury within amalgams stable?
When mercury ends up in Colorado’s lakes, rivers and streams, microorganisms convert some
portion of this mercury into methylmercury, a toxic compound. Methylmercury bioaccumulates
in fish, and presents a health risk to the humans and wildlife that consume the fish.
Dental offices contribute to the release of mercury to surface water through normal operating
practices that involve handling and disposal of mercury-containing amalgams. The
bioavailability of mercury contained in waste amalgam is currently under study, and therefore the
relative contribution of ‘dental mercury’ to the greater mercury problem is unknown.
Nonetheless, Colorado has joined other states in taking a precautionary approach to the handling
2
and disposal of waste dental amalgam.
Aren’t chair-side traps and vacuum filters enough?
Chair-side traps and vacuum filters are designed to protect the dental equipment. While doing so,
traps and filters do capture a portion of the mercury waste. However, the amount of mercury that
is actually captured by the traps and filters varies. One study found that 40.2% of the amalgam
3
removed was trapped by the conventional traps, and 59.8% by passed both traps.
Can the city of Boulder provide any type of scientific study data that demonstrates that the
primary source of mercury contamination actually, in fact, is from dental office effluent?
There is a large body of published data detailing the impact of wastewater containing amalgam on
local wastewater treatment plants. Sampling of wastewater contributions throughout the city of
Boulder has also shown elevated mercury concentrations from dental offices. Dental office
samples collected in 2006 showed a concentration range of 140 ng/l to 15,000 ng/l. Dental office
samples collected in 1998 showed a concentration range of 400 ng/l to 160,000 ng/l.
In comparison monitoring around Boulder from university sites, hospital sites, domestic sites and
commercial sites, mercury levels have predominately been below detection (EPA 245.1).
Occasional peaks are measured but are a rarity rather than the norm. Finally, industries involved
in manufacturing are monitored for mercury and regulated according to local pollutant
limitations.
There are over ninety (90) dental offices in Boulder; if each of these offices contributes just a
small amount of dental amalgam containing mercury then Boulder's wastewater plant has a
problem. The wastewater treatment plant is designed to treat household wastewater and has no
Appendix #3
February 26, 2007
specific removal technologies for mercury.
What is the approximate dental contribution to mercury within the wastewater stream?
Although dental sources make up little of the total environmental mercury, dental practices are
one of the main contributors to mercury within the wastewater stream. A 2001 study by the
Association of Metropolitan Sewerage Agencies looked at WWTPs and found that dental
practices were, "by far" the greatest contributors. Furthermore, the report found that dentists
4
accounted for 40% of the mercury load to WWTP.
According to the ADA, 35 to 45 percent of the mercury entering POTWs comes from dental
5
facility sources.
How much will a separator cost?
Typical costs range from $300-$2000 in purchase, approximately $200 for installation and
7
between $75-$750 for annual maintenance (including waste disposal).
8 7
Please see Table 1 & 2: ADA & EPA Reg. 5
Do separators truly remove mercury from the wastewater stream?
A report by the ADA showed that the amalgam separators they tested removed at least 96.09% of
the amalgam in samples with particle-size distributions as specified by the International
Organization for Standardization (ISO). All twelve separators that were tested exceeded the ISO
8
11143 standard.
A study conducted by the state of Vermont Environmental Conservation demonstrated that there
are several commercially available collectors that can reliably perform with minimal
9
maintenance.
How long will dental practices have to complete installation and be in compliance with the
proposed regulations?
If regulations are finalized, dentists will have six months to implement and self certify
compliance with Best Management Practices. After the effective date, dentists will have one year
to install an amalgam separator.
Isn’t the problem with environmental mercury due to air disposition and runoff from
historic mining activities and not dental offices?
Although it may be true that dental offices contribute a small percentage to the total
environmental mercury problem, dental offices are an identifiable and preventable source of
mercury within the wastewater stream. Furthermore, dental offices are a significant contributor
to the mercury levels within the wastewater stream.
Discharges from dental facilities to WWTPs are a minor source of mercury to the nation’s
waters. Why waste the resources?
Where mercury is not a problem at the WWTP, the WWTP is not required to do anything (though
Reg. 8 supports voluntary programs). The contribution of mercury to a WWTP and the receiving
water may be significant in some cases. Where a discharge is above the level allowed by the
underlying water quality standards, the mercury must be reduced. The Pretreatment Program
addresses these sources while other environmental groups address other sources of mercury.
Implemented together, the various environmental programs will reduce the overall mercury load
6
to the environment.
Appendix #3
February 26, 2007
What other sources of mercury are there?
Mercury is also found in medical settings, laboratory settings and in residential settings.
Thermometers, pharmaceutical products, cleaning and even degreasing products can contain
small amounts of mercury. In medical and laboratory settings, users are encouraged find alternate
chemicals or manage the chemicals such that mercury does not enter the environment, including
the sewer system. Residents may drop off mercury containing products to the Boulder County
Household Hazardous Waste Collection Center (303) 441-4800.
http://www.co.boulder.co.us/recycling/hhw/hhwhome.htm
Sources:
1. American Dental Association (July, 2002). “ADA Statement: Dental Amalgam in Dental
Office Wastewater”
http://www.ada.org/prof/resources/positions/statements/amalgam4.asp
2. Colorado Department of Public Health and Environment: Dental Mercury and the
Environment, a Fact Sheet for Dentists. 2004.
3. Adegbembo, A., Watson, P., Lugowski, S. “The Weight of Wastes Generate by Removal of
Dental Amalgam Restorations and the Concentration of Mercury in Dental Wastewater.” J Can
Dent Assoc 2002; 68(9) 553-58.
4. Association of Metropolitan Sewerage Agencies, 2002 (March, Amended July 2002).
“Mercury Source Control & Pollution Prevention Program Evaluation. Final Report.” Prepared
by Larry Walker Associates.
5. Eichmiller, Statement of the ADA to the Wellness and Human Rights Subcommittee,
Government Reform Committee, United States House of Representatives, on The
Environmental Impact of Mercury Containing Dental Amalgam, October 8, 2003.
6. US EPA Reg. 8 POTW Mercury Control Strategy Draft. May 2005.
7. EPA Reg.5: Options for Dental Mercury Reduction Programs: Information for State/Provincial
and Local Governments. Revised August 2004.
http://www.epa.gov/region5/mercury/dentaloptions3.pdf
8. Fan, P.L., Batchu, H., “Laboratory Evaluation of Amalgam Separators.” JADA. 2002; 133,
577-599. http://www.ada.org/prof/resources/pubs/jada/reports/report_separator.pdf
9. Vermont Dental Amalgam Separator Pilot Project. August 2004.
http://www.anr.state.vt.us/dec/ead/mercury/PDF/AmalgamSeparatorReport.pdf
Additional Sources:
PACE- Partners for a Clean Environment, www.bouldercolorado.gov/www/pace/index.html