Ontario Water Resources Act (Section 17 and 24 - R.S.O. 1980)

This procedure describes the requirements for the provision and operation of sewage works effluent disinfection facilities. The measures described in this and related procedures are to ensure both public health and aquatic life are adequately protected from sewage works discharges in a most cost-effective manner.

This procedure is written in support of Guideline F-5 of the Manual of Guidelines and Procedures which deals with the levels of treatment required for sewage works in Ontario. Except where exempted by the Guideline, disinfection requirements apply to all municipal, institutional and private communal sewage works discharging to surface waters and requiring Ministry approval under Section 24 of the OWR Act, RSO 1980.

Rationale

Sewage works discharges to surface waters often constitute a significant input source of pathogenic micro-organisms to the receiving waters. Such discharges represent a potential menace to water supplies, to recreational and agricultural uses of receiving waters, and to various other water related activities. Inactivation of pathogenic micro-organisms at sewage works can significantly reduce the dissemination of pathogens to the water environment and break the potential cycles of pathogen-associated infections at the source.