Source Control (FOG)


Contaminants that enter the sanitary sewer system pose a risk to sewerage system workers, to the general public, to the collection and treatment works and to the receiving environment. These contaminants can include:

  • Cleaning chemicals
  • Detergents (phosphorus)
  • Drugs and medicines
  • Fats, oilsand grease (FOG)
  • Paints and paint thinner
  • Other toxic materials

Effects on Workers and the Public

Toxic, flammable or explosive gases in the sewer system can be dangerous to sewer system workers and the public. Sewerage system worker safety is also put at risk by reduced oxygen for breathing.

Treatment Plant

The biological wastewater treatment processes at the Water Pollution Control Centre depend on healthy bacteria to remove contaminants. Toxic materials can upset biological treatment processes at the treatment plant, which can be expensive to correct and can also cause the plant to discharge poor-quality effluent to the lake.

The Environment

High amounts of phosphorus from detergents in the lake can cause algae growth, which can cloud the water, and can also lower oxygen levels, threatening aquatic life. Heavy metals can collect in sediments and the biosolids that are a byproduct of wastewater treatment. These stabilized / digested biosolids are used as a component in making topsoil; it is essential to keep them as contaminant-free as possible.

How to Keep Contaminants Out of the Sanitary Sewer System

  • Conserve water and install water-saving devices on shower heads, taps and toilets.
  • Use phosphate-free detergents / soaps and cleaners, and reduce amounts used below the manufacturers' recommendations.
  • Don't use toxic cleaners; use green products or compounds such as borax, baking soda and vinegar.
  • Don't dispose of any poisons or toxins down the drain.
  • Don't drain swimming pools or hot tubs into the sanitary sewer.
  • Don't use the toilet to dispose of plastics such as cleaning swabs, feminine hygiene applicators, etc.
  • Dispose of fats, greases, oils, pesticides / herbicides and other toxic substances at approved collection depots.