Water

Refinery effluent discharges

Water discharged back into the environment is called effluent. Effluent treatment makes sure that water releases meet federal water quality standards.

Canadian petroleum refineries have reported effluent discharge data to Environment Canada for more than 30 years. Even refineries built before these regulations follow strict industry-wide guidelines.

Environment Canada requires five specific substances to be measured, including: oil and grease, sulphide, ammonia nitrogen, phenols, and total suspended solids. In 2003, industry discharges of all five substances were 58 to 94 per cent lower than limits set by Environment Canada regulations.