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.

By following the code of practice, you will significantly reduce the amount of contaminants that end up in our oceans. Mercury, lead and other metals are now much less common in the waters off our region, thanks in large part to source control efforts and to the efforts of local dentists.

Continued effort will mean our ocean will be cleaner and safer for everyone.

You can protect our environment, reduce your own liability and provide a greener, improved business image in your community.

• Follow the code for proper transport and disposal of hazardous wastes, such as mercury and silver.
• Install and properly maintain treatment works (amalgam separators) in your dental office.
• Maintain comprehensive records to ensure wastes are being disposed of properly.

Other wastes from dental offices can also be a concern if discharged into the sewer system. The best management practices listed in the code for dental offices has suggestions for how to handle waste such as:

• cleaning solutions and disinfectants,
• pharmaceutical wastes, and
• biomedical wastes.

By reducing waste overall and disposing of waste in the proper manner, you can help protect our region's environment.