Commercial Stormwater Management: Compliance and Best Practices for Ontario

Commercial Property Services

Commercial property owners have specific obligations under Ontario's stormwater management regulations — understanding these requirements protects you from environmental orders and fines.

Ontario's Environmental Protection Act and municipal stormwater management by-laws require commercial properties to prevent contaminants from entering storm drainage systems. Oil, grease, chemicals, sediment, and construction debris are all regulated under these provisions.

Industry Best Practices

Oil-water separators are required at commercial properties where vehicle maintenance, fuelling, or significant oil storage occurs. These devices separate petroleum-based contaminants from stormwater before it enters the catch basin system. Annual inspection, oil removal, and certification that the separator is functioning within specification is a standard compliance requirement.

Spill response planning is required for properties that store chemicals, fuels, or regulated substances. A written spill prevention and emergency response plan specifying containment procedures, required absorbent materials, and emergency contacts reduces the response time and environmental impact if a spill occurs.

How D&D Commercial Services Can Help

Construction site stormwater management is regulated under Ontario's Construction Act and municipal stormwater by-laws. Any construction disturbing more than 1 hectare of ground typically requires a Stormwater Pollution Prevention Plan (SWPPP) specifying erosion controls, sediment traps, and runoff management.

Low-impact development (LID) features — rain gardens, permeable pavement, bioswales — are increasingly encouraged or required in commercial development permits. LID features manage stormwater on-site, reducing peak flows to municipal systems and improving groundwater recharge. Maintaining these features in functioning condition is the property owner's responsibility.