Dental offices

How does the by-law address my dental practice?

The City of Greater Sudbury's Sewer Use By-law requires dental offices* to follow practices which prevent mercury found in dental amalgam waste and other heavy metals from entering the municipal sewage system and the environment. Under the by-law, dental offices which do not currently follow best management practices are required to comply with the following, no later than September 15, 2011:

  • Install, operate and properly maintain a certified amalgam separator on all fixtures to meet the by-law limit of 0.01 mg/L for mercury.
  • Ensure that all cuspidors are connected into the amalgam separator intake line.
  • Clear traps and pipes of any residual mercury deposits. Amalgam is very dense and will accumulate in plumbing causing blockages.
  • Install, operate and properly maintain an on-site silver recovery unit to remove silver from x-ray film processing solutions before discharge into the sanitary sewer system (not applicable if digital photography is used).
  • The silver recovery unit must be designed to ensure that concentrations of silver are not in excess of 5 mg/L at time of discharge. Silver released from film processing solutions is a non-renewable and precious material and should be recovered for recycling and reuse.
  • Keep accurate and up-to-date records of equipment inspections and maintenance.
  • Contact a certified hazardous waste carrier for recycling or disposal of dental amalgam waste and photo finishing chemicals. Never pour chemical concentrates down the drain.

*Please see the City of Greater Sudbury's Sewer Use By-law for exempt dental practices.

Why is dental waste a concern?

Studies have shown that wastewater from dental offices contains elevated concentrations of heavy metals. The sources of these metals include placement and removal of amalgam fillings (mercury, silver and other materials such as copper, tin or zinc) and disposal of x-ray film processing solution (silver).

Elevated levels of heavy metals discharged to the sanitary sewer system pose a significant risk to the environment. Mercury is of particular concern as it can lead to the formation of Methylmercury, a deadly neurotoxin most commonly associated with 'Minamata disease”.

Please ensure that all chemicals are properly contained and labeled in case of spill or leak. Never dilute effluents with clean water to lower metal concentrations or to balance the pH. Dilution for discharge is prohibited under provincial environmental legislation.

Conditions which may result in By-law compliance audits and enforcement:

  • Failure to install certified amalgam separator(s),
  • Failure to connect cuspidor(s) or other drains to amalgam separator(s),
  • Failure to routinely inspect or maintain amalgam separator(s),
  • Failure to install, operate and maintain silver recovery unit(s),
  • Failure to recycle or dispose of dental amalgam waste and silver in a certified manner,
  • Failure to keep accurate records of equipment inspections and maintenance for review by municipal officials upon request,
  • Failure to comply with allowable parameters for discharged substances. Please see the City of Greater Sudbury's Sewer Use By-law for Limits for Sanitary Sewer Discharge.

What are the penalties for non-compliance?

Customers who do not comply with the by-law are liable for a fine of between $5,000 and $10,000 per day for a first offence. Corporations are liable for a fine of up to $50,000 per day for a first offence.

To learn more about the City of Greater Sudbury's Sewer Use By-law:

Telephone: 705-675-2622, ext. 200