Water Legislation and Substance/Quality Database Canadian Water and Wastewater Association

Frequently Asked Questions
Industrial Wastewater Activities
Draft

Return to Frequently Asked Questions
Search the Database

Do industries discharge directly to the environment or to the sanitary sewer system?
Both. Provincial/territorial and federal legislation does regulate discharges directly to the environment through various statutes. They vary from jurisdiction to jurisdiction and each specific provincial/territorial government should be consulted for information. The federal Fisheries Act regulations such as Pulp and Paper, Metal Mining, Food Processing, etc specify requirements for each industrial sector. For example, Ontario has nine regulations for specific industrial sectors developed under the Environmental Protection Act.

Industries can discharge to the sanitary sewer systems. In many cases there are certain requirements on the industry to ensure that they do not discharge certain substances; they discharge under non peak flow conditions for the sewer system; and/or they must meet limits for components of their waste. These are usually referred to as "sewer-use by-laws" and are developed by the municipality in conjunction with the province.

What does the industry do if it wants to discharge to the sewer but can’t meet the limits set out?
In that instance, the industry must evaluate its process and see how it might eliminate the problem through some operational changes. Or, they may have some pre-treatment onsite to reduce a specific substance prior to release to the sewer system.

Industries may use water in a cooling process. Can they discharge this water?
It depends on the industry, type and levels of contaminants, and quantities. Many industries have found that they can recycle their cooling water and therefore have a closed loop system so there is no need to discharge to the environment or the sanitary sewer system.