ULC 656 PDF

Please note: All interim revisions for this edition available at time of your purchase will be included.

This Standard provides minimum requirements for shop fabricated single-wall or double-wall oil-water separators intended to collect and separate free oil from water by gravity separation at an inlet free oil concentration not exceeding 2 000 mg/L.

NOTE: Includes separators intended to collect and separate rainwater or wastewater containing free oil.

In addition to this Standard’s performance requirements for oil water separators that primarily evaluate the separator’s effectiveness and mitigate environmental hazards from loss of liquid containment under expected normal conditions; optional construction and/or performance requirements, and associated ratings intended to address more severe conditions associated with the effects of Climate Change are included in Appendix B.

These oil-water separators are also installed for the capture and retention of oil spills under dry weather conditions up to the free oil retention capacity of the oil-water separator.

These oil-water separators are intended for installation and operation in accordance with, but not limited to, the following:

• Manufacturer's instructions;
• CCME PN 1326, Environmental Code of Practice for Aboveground and Underground Storage Tank Systems Containing Petroleum and Allied Petroleum Products;
• CPPI Code of Practice for Management of Water Effluent Quality at Petroleum Storage and Distribution Facilities; and
• Regulations of the authority having jurisdiction.

NOTE: Collection and disposal of the effluent, free oil, and separated solids from oil-water separators is beyond the scope of this document. Consult the authority having jurisdiction for disposal requirements for these substances.

NOTE: The accumulated solids are to be removed as recommended in the Manufacturer’s Operation and Maintenance Instructions to ensure no adverse effect on the performance of the oil-water separator.

The requirements of this Standard apply to all oil-water separators. Users are advised that the requirements of AHJs may impose additional performance and testing criteria beyond those described in this document.

Except for optional Climate Change Adaptation requirements in Appendix B, which includes optional construction and/or performance requirements, and associated ratings intended to address more severe conditions associated with the effects of Climate Change, these requirements do not cover special evaluations for resistance to, or use after, earthquakes, floods, high wind events, or other natural disasters.

NOTE: See the Note at the beginning of Appendix B for further information on the terms “Adaptation” and “Mitigation”, as they pertain to Climate Change.

These requirements do not cover grease interceptors. Refer to the CSA B481 series of standards for grease interceptors which are utilized in sanitary drainage systems for the interception of non-soluble organic fats, oils, and greases from animal or vegetable sources.