STATE OF WASHINGTON

DEPARTMENT OF ECOLOGY

P.O. Box 47600 z Olympia, Washington 98504-7600 

(360) 407-6000 z TDD Only (Hearing Impaired) (360) 407-6006

Memorandum of Understanding 

Washington State Department of Ecology 

And 

Washington State Dental Association 

Parties

The Washington State Department of Ecology (“Ecology”) is the state’s environmental 

agency that has enforcement responsibility under federal and state water and waste 

environmental laws for the purpose of this Memorandum of Understanding (MOU). Ecology has 

delegated permitting and compliance authority and responsibility for implementing the federal 

Clean Water Act pretreatment program to the following municipal jurisdictions: Everett, King 

County (Metro/King County service area), Lynnwood, Olympia (LOTT), Pierce County 

(Chambers Creek service area), Port Angeles, Richland, Spokane, City of Tacoma, Vancouver, 

and Yakima. These jurisdictions are the wastewater management authorities for the local 

sewerage systems pertinent to dental offices in these areas. 

The Washington State Dental Association (“WSDA”) is a voluntary membership association 

of Washington dentists. 

The parties recognize there are an estimated 2,600 dental offices in Washington State. 

Purpose of MOU

Both Parties acknowledge the importance of implementing mercury reduction actions 

published in the Washington State Mercury Chemical Action Plan, “Dental FacilitiesRecommended Actions.” 

Ecology’s objective is to reduce the amount of dental amalgam waste that may now be 

discharged from dental offices to sewer treatment plants or into privately-owned onsite septic 

systems. The purpose of the MOU is to recognize WSDA’s and Ecology’s mutual desire to 

achieve compliance and protect Washington’s environment within the term of this MOU by 

timely incorporation of best management practices regarding regulated waste management in 

Washington State dental offices. 

Through their mutual discussion of dental amalgam waste issues, Ecology’s representatives 

and the WSDA Task Force on Dental Amalgam Waste determined the common objectives of 
August 1, 2003 

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Ecology and the WSDA are most likely to be achieved by implementing the steps outlined 

below in this MOU. 

Nature of MOU

The MOU addresses the effective management and disposal of mercury generated 

from dental practice such that the water and waste regulations are complied with to protect 

Washington’s environment. The advocacy of BMPs in this MOU does not address dental 

standards of practice related to therapeutic use and placement of amalgam fillings. 

Ecology is exercising its prosecutorial discretion to pursue a voluntary compliance strategy 

with WSDA to achieve a significant reduction of mercury waste from dental offices. This 

achievement will be consistent with the goals of the Washington State Mercury Chemical 

Action Plan, (Department of Ecology Publication No. 03-03-001, January 2003). 

WSDA supports the science that supports the safety of dental amalgam. The WSDA 

cannot bind its membership, but joins in this MOU to advocate with dentists to voluntarily 

adopt amalgam best management practices (BMPs) described herein. The WSDA has as one of 

its purposes the advancement of the science of dentistry. This includes progress in the effective 

management of dental amalgam waste. 

Best Management Practices

Ecology and WSDA each will support and advocate that dental offices implement best 

management practices (BMP) concerning dental amalgam waste as follows: 

1. Install, use and maintain International Standards Organization (ISO) certified 

amalgam separators. Installation applies to all offices regardless of sewer disposal type 

(public system or septic), but would not apply to practices that are restricted 

exclusively to these dental specialties: Orthodontics and Dentofacial Orthopedics; 

Oral and Maxillofacial Surgery; Oral Medicine and Pathology; Oral and Maxillofacial 

Radiology; Periodontics; and Endodontics and Prosthodontics, provided amalgam 

fillings are neither placed nor removed in these practices or are only placed or 

removed on less than 10 practice days during the year. 

2. Collect all amalgam waste (both scrap and contact amalgam) in separate container. No 

dangerous waste or amalgam is to be placed in the infectious waste “red bag.” 

3. Properly manage and dispose of all other dangerous waste streams generated by the 

dental office (e.g., x-ray wastes, or lead foils/aprons). 

4. Properly dispose of all scrap amalgam waste from traps, filters and separators with a 

licensed treatment, storage, disposal or recycling facility. 

5. Keep amalgam out of sinks and never rinse amalgam waste down the drain. 

6. Clean or replace chair-side traps on a regular schedule and properly dispose of 

amalgam waste. 

7. Clean vacuum pump filters regularly, according to the manufacturer’s 

recommendations. 

8. Maintain all disposal records on site for three (3) years. 
August 1, 2003 

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Statewide Dental Amalgam Waste Reduction Education and Outreach

Ecology and WSDA will jointly develop a statewide dental amalgam waste reduction 

strategy of specific actions to inform dental offices about relevant law and regulation regarding 

management of dental amalgam waste and to encourage voluntary implementation of BMPs 

for dental offices. The focus of the outreach will be to distribute the BMPs and spell out 

dentist’s responsibilities to correctly manage waste dental amalgam and all other dangerous 

wastes. Ecology will identify to WSDA appropriate recycling facilities, hazardous waste 

management facilities, and moderate risk waste facilities that can be used to manage wastes 

from dental activities. Ecology will offer technical assistance, and if requested, will provide 

presentations at state or regional conferences or workshops. The strategy may use the resources 

available to Ecology and WSDA within the limits of each organization’s budget intended for 

this purpose. Ecology and WSDA will jointly develop a timetable for implementing actions in 

this strategy following mutual discussion of both parties of the strategy. 

Outcomes

The parties agree that the goal of this MOU is that Washington dental offices will 

implement BMPs, to be measured as follows: 

1. Ecology and WSDA will jointly develop a reporting system for notification by the 

dental office of the installation of an amalgam separator system in the dental office. Reports 

will specify the date of installation, dental office location and owner, model of separator, and 

the name, address and phone number of the installer. 

2. Installation notification will be made to Ecology, the sewer treatment plan permit holder 

within which jurisdiction the dental office is located, and to the WSDA at the end of each 

quarter of the year. 

3. Prior to August 2004, Ecology and WSDA will conduct a survey of dentists to establish 

a baseline level verification of dental offices following the prescribed BMPs. A second survey 

will be conducted prior to August 2005 to determine if the number of dental offices following 

the BMPs has increased. Results of the survey will be shared with local governments. 

During the transition outlined in this MOU, it is understood to be a voluntary program by 

dental offices. Ecology will not seek to require dental offices to have new discharge permits or 

compliance reporting while this MOU is in effect but will have enforcement discretion to apply 

applicable laws and regulations to dental offices upon completion of the effective date of this 

MOU. 

Each year within a few months after the report count is available, WSDA and Ecology 

representatives will meet to review and discuss progress made and whether any practical, 

additional steps could be effective to achieve a higher rate of voluntary participation. 
August 1, 2003 

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Both Parties are committed to achieving compliance through this MOU. At the termination 

date of this MOU, our agreed goal is that dental offices in the State of Washington will be 

operating under the prescribed BMPs and managing mercury waste in a proper manner, 

consistent with the Washington State Mercury Chemical Action Plan recommendations. 

Notification

Communications and notices between the parties will be as follows: 

If to Ecology: Michael J. Gallagher 

 Mercury Chemical Action Plan Coordinator 

 Department of Ecology Environmental Assessment Program 

 P.O. Box 47600 

 Olympia, WA 98504-7600 

If to WSDA: David Hemion 

 Assistant Executive Director 

 Washington State Dental Association 

 2033 6th Avenue Suite 333 

 Seattle, WA 98121 

Recognition

Ecology and WSDA will encourage dental offices to self-report compliance on separator 

installation and implementation of BMPs. Dental offices will be instructed to submit their 

reports to Ecology, which will provide copies to WSDA at the end of each quarter of the year. 

Ecology and WSDA agree to provide a “certificate of recognition” program to identify 

those dental offices that have met the requirements of this MOU. Dental offices submitting a 

notice in general conformity with the above reporting provisions for separator installation and 

BMP will be provided within thirty (30) days with a certificate of recognition. A proposed 

example is attached as Exhibit A. 

Effectiveness

This MOU will take effect on the date signed by Ecology once approved by the WSDA 

Board of Directors, and remain in effect for a period of two (2) years from the date of signature 

by Ecology. 

Executed to take effect as stated above. 
August 1, 2003 

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August 1, 2003 

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Exhibit A 

Certification of Recognition

The dental office of Dr. __________________________ follows waste-disposal best management 

practices in accordance with recommendation of the State Department of Ecology and 

the Washington State Dental Association. 

The State of Washington and WSDA express appreciation. 

By 

Title, Washington State Department of Ecology 

By 

President , Washington State Dental Association