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Multi-state Mercury Products Campaign 

Environmental Law and Policy Center * Mercury Policy Project * 

Natural Resources Defense Council 

April 1, 2011 

On behalf of the Multi-state Mercury Products Campaign1, the Environmental Law and Policy 

Center, the Mercury Policy Project, and the Natural Resources Defense Council, we respectfully 

submit the following comments on important elements that should be included in the U.S. 

Environmental Protection Agency’s (EPA’s) proposed dental facility effluent guidelines. 

Unlike most pretreatment standards which specify a concentration-based limit, we anticipate a 

proposal requiring the use of certain equipment such as amalgam separators. Under these 

circumstances, it is vital that the proposal also include a comprehensive set of best practices 

and operational requirements which ensure the equipment is functioning and mercury 

discharges to POTWs are otherwise minimized. Toward this end, these comments focus on the 

best practices and operational requirements necessary for an effective rule. 

Standard 

The dental facility effluent guideline should require an amalgam separator or equivalent 

technology which includes each of the following characteristics: 

1. Certified compliant to achieve solids removal efficiency of 99% or greater for separators 

installed on or after the effective date of the rule, 

2. Receives all dental facility waters likely to come into contact with dental amalgam waste 

prior to discharge, including wastewater from chair-side water collection units, sinks, 

traps and drains, and 

3. Sized appropriately for the dental office based on anticipated wastewater flow rate 

(number of chairs served, etc.). 

Required Separator Operation and Maintenance 

The following requirements should be included in the guideline to ensure that the amalgam 

separator is properly operated and maintained: 

1. Notification requirements. Dental facilities should be required to provide notice to the 

control authority that includes a certification of separator installation per manufacturer 

specifications and compliance with Best Management Practices (BMPs). 

2. Maintenance and corrective action. The dental facility must: 

 

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 The Multi-State Mercury Products Campaign works to advance policies to reduce and eliminate mercury releases 

to the environment from products. The campaign includes over twenty state and national environmental and 

public health advocacy groups working together to reduce and eliminate several of the largest product uses of 

mercury and to reduce mercury releases to the environment. 
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a. Inspect the separator at least weekly to ensure proper operation. 

b. Maintain the separator in accordance with manufacturer specifications. This 

maintenance includes changing the collection boxes or cartridges in accordance 

with manufacturer specifications and recycling or managing the spent amalgam 

collection boxes or cartridges in accordance with state or local law. 

c. Periodically certify compliance with separator mercury removal efficiency 

standards and maintenance requirements, and BMPs. 

d. Notify the control authority within 24 hours after an alarm is triggered or there is 

some other indication of separator malfunction. The facility must undertake 

corrective action within 24 hours and must submit a report to the control 

authority that corrective action has been completed within 72 hours. 

e. Disinfect separators on a regular basis as recommended by the vendor, using 

non-corrosive, non-oxidizing bio-degradable products which will not dissolve 

mercury (no bleach). 

3. Record-keeping requirements. The dental facility must maintain on its premises the 

following records for 5 years from the date they are created: 

a. The manufacturer, model number, serial number, date of installation and 

number of chairs serviced by the amalgam separator.

b. Written or computerized logs of amalgam waste generated and removed from 

the vacuum system or plumbing. 

c. Receipts, manifests, bill of lading and/or tracking number or other certified 

documentation from the recycler or shipping company, and receiving facility for 

all amalgam waste shipments. 

d. Amalgam separator and chair-side trap installation, inspection and maintenance, 

and servicing records, including date of installation, date of each inspection 

(including dates when separator alarm is triggered), date of service of each 

separator or trap, date of description of routine and non-routine maintenance 

activities conducted, and corrective actions, including reason for 

malfunction/bypass, if found. 

BMPs Specified in Rule 

Strong BMPs are also an important element of an effective dental facility effluent guideline to 

further minimize mercury releases to wastewater treatment systems. EPA should include, at 

least, the following BMPs as part of the effluent guideline. 

The dental office must NOT do any of the following: 

1. Flush devices containing amalgam or amalgam waste, such as non-contact amalgam or 

salvaged amalgam restoration pieces, down the drain or toilet. 

2. Rinse devices, including reusable traps, containing amalgam over drains or sinks. 

3. Decant any radiographic fixer, water, or other liquid, containing dental amalgam or 

liquid in which amalgam was stored, down the drain.

4. Rinse vacuum pump filters over drains or sinks. 
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5. Use sodium hypochlorite (bleach) or other chlorine containing products or oxidizing 

agents that would dissolve mercury to clean or flush vacuum or wastewater lines. 

6. Dispose expended capsules down the drain or toilet.

In addition, the dental facility must do the following: 

1. Clean screens, traps and filters before cleaning vacuum lines. 

2. Use chair-side traps to capture amalgam waste using the finest screen possible. 

3. Maintain vacuum pumps, chair-side traps, and other equipment in accordance with 

manufacturer specifications, and recycle or manage filters and other wastes in 

accordance with state and local law. 

4. Discontinue use of bulk (elemental) mercury and use only pre-capsulated dental 

amalgam. Locate any bulk or elemental mercury onsite and recycle or manage in 

accordance with state and local law. 

5. Establish a training program covering the requirements of this rule and applicable state 

law; the operation and maintenance of discharge control equipment; and proper 

handling, management and disposal of mercury-containing material and fixer-solutions. 

6. Make information accessible to patients regarding the health and environmental risks 

posed by mercury and the availability of non-mercury alternatives for dental 

restorations. 

7. When plumbing parts are removed or cleaned in the office, the sludge inside the piping 

should be inspected for the presence of mercury amalgam. If amalgam is present, it 

should be removed and managed along with other contact amalgam waste. 

Thank you for your consideration. Please feel free to contact me if you have any questions or 

need further information. 

Sincerely, 

Mae Wu 

Natural Resources Defense Council 

1200 New York Ave., NW 

Washington DC 20005