Dental

• dental amalgam
• disinfectants
• chemiclave solutions
• cleaning agents and rinse solutions
• spent x-ray processing solutions
• pharmaceuticals

Although the volume of these materials discharged from an individual office may be small, the cumulative amount of waste from all dental offices in the CRD has the potential to harm marine life and affect treatment facilities and biosolid usability. 

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

Elevated levels of heavy metals discharged to the sanitary sewer system or to septic fields can pose a significant risk to the environment.

• Mercury, copper and zinc levels are some of the main contaminants identified near marine outfalls in the CRD region. Mercury is known to accumulate in the tissues of fish, plants and mammals and to bioconcentrate within the food chain. Metals can also contaminate marine sediments.
• When there are elevated levels of heavy metals in biosolids, the CRD's options for biosolids reuse are limited.
• Heavy metals can also accumulate in septic fields and tanks. Contaminated fields may restrict future land use designations and the landowner may be liable for clean-up costs. 

In many cases, companies require a waste discharge permit to discharge industrial or commercial wastes into the sewers. However, the CRD’s sewer use bylaw also provides for the discharge of certain types of waste under industry-specific codes of practice. 

A code of practice is a regulatory document, developed by the Capital Regional District, which contains mandatory sanitary sewer discharge standards for specific industrial, institutional, or commercial sectors. Codes of practice set out minimum effluent treatment, equipment maintenance and record-keeping requirements for various sector operations. A business or organization operating under an approved code of practice does not require a waste discharge permit under the CRD sewer use bylaw. 

The code of practice for dental operations (Schedule “L”) describes the rules as defined by the CRD for the disposal of liquid waste from dental operations into the sewer system. 

Important documents for dental operations: 

• Waste Discharge Assessment Form [PDF/543KB]
• Dental Operations Maintenance Records [PDF/48KB] 
• Code of Practice Schedule “L” 
• CRD Sewer Use Bylaw No. 2922 

Installing Amalgam Separator:

• dental operations must install and maintain an amalgam separator that meets current ISO standards.

OR

• collect and transport waste off-site for proper disposal.

Location of Amalgam Separator:

• must be readily and easily accessible for inspection, maintenance, repair or replacement.
• must not be in a confined space.
• amalgam separator and stored liquid waste containers must be located so that any accidental spills or leaks will not result in wastewater containing amalgam entering the sewer.
  • if this is not possible then an operator must install spill containment

Flow Control:

• If located downstream from wet vacuum system, flow control fittings must be place inside the wet vacuum system or on the water supply line for the system. Fittings must be set so that it does not exceed the maximum inlet flow rate of the amalgam separator.

Amalgam separator cartridges must be replaced when:

• expiration date has been reached.
• warning level specified in the ISO standard has been reached.
• results from analytic data of amalgam separator effluent are found to be greater than or equal to 2mg/L. 

Install a sampling point downstream from the amalgam separator but upstream of the discharge point for other wastes and must:

• always be easily accessible for inspection and sampling.
• be installed so that the total flow from the amalgam separator maybe be intercepted and sampled. 

When an Amalgam Separator is installed:

• Operators of dental operations must keep the following materials on site and available for inspection:
  • an operation and maintenance manual and ISO Standard certification documents for the installed amalgam separation equipment
• A record book that includes the following operation and maintenance information recorded for the previous five years:
  • date of installation and name of supplier
  • serial number and expiry date
  • maximum flow rate and maximum capacity rating
  • dates of inspection, maintenance, repair, cleaning and replacement
  • date and descriptions of all operations problems, spills, leaks or collecting container failures and what actions were taken
  • name, address and telephone number of any service provider that provided maintenance or waste disposal
  • dates of pick-up of the collecting container, volume of waste disposed and the location of disposal 

If you operate in North Saanich, Central Saanich or Sidney, then you need to know about Saanich Peninsula Stormwater Bylaw No. 4168 [PDF/304KB] requirements. 

• Never pour any fluids, wash/rinse water, wastewater or spills into storm drains, ditches, parking lots or outdoor work areas.
• When hosing or washing equipment or surfaces outside, do not let the runoff water enter the storm drain.
• Regularly inspect and maintain any parking lot catch basins.
• Store waste products and outdoor containers under covered areas with appropriate spill containment. Inspect after a rainstorm to make sure no materials leaked out.
• Educate staff about spill prevention and response and have spill plan and kit available.
• Regularly inspect and maintain any parking lot catch basins, cleaning them out at least once per year.