squaregrateCatch basins are chambers, usually with a grate, which collect stormwater. They are very common in parking lots and on streets. In addition to rainwater, catch basins can collect litter, car fluids (oils, gas, antifreeze, etc.), metals, sediments, leaves, sand, grit and/or soil.

The catch basin helps remove pollution by allowing solids to settle and light materials to float. These units discharge to stormwater systems that lead to nearby water bodies, such as streams, wetlands or the ocean. When maintained and serviced properly, catch basins effectively reduce the amount of pollution leading to our waterways, beaches and marine shorelines.

With a changing climate and more intense rainfall in the winter months, it is even more important to clean out catch basins to avoid flooding, damage to your and nearby businesses and to protect the environment.

Catch Basin Best Management Practices

Inspect Regularly

  • Sweep any leaves, garbage and debris away from the grate to ensure it does not block the flow of stormwater.
  • Inspect your catch basin every three months to check sediment and floating oil levels. This will help determine rate of accumulation so you can develop a proper cleaning schedule.

Clean Annually Using a Qualified Company

Property owners and waste generators are responsible for cleaning out catch basins. Clean your catch basin at least annually before the fall rains start in September or October. This helps prevent flooding and damage to your and neighbouring businesses.

Hire a qualified company to pump out your catch basin as they know where to properly dispose of the waste. See the Trucked Liquid Waste Service Provider Directory for a list of companies that provide this service. If the waste is classified as hazardous, haulers need a license from the provincial government to haul and dispose of it.

When transporting and disposing of catch basin waste, a manifest form needs to be completed by the hauler or waste generator.

  • Example Waste Manifest form
  • Keep Records

    Catch basin owners are responsible for ensuring that inspection and maintenance records are kept for two years or per municipal regulations.

    Check with your municipality for record keeping requirements. Properties in Central Saanich, North Saanich and Sidney are under the Saanich Peninsula Stormwater Source Control Bylaw No. 4168.

    Be Spill Ready

    In a parking lot, spills of oil, antifreeze or other engine fluids must be cleaned up immediately in order to prevent these substances from entering the catch basin and stormwater system. Prepare a spill response plan and keep a spill kit on hand in case of emergency spills. Keep a record of any spills, including:

    • Date of spill
    • Type of material spilled
    • Quantity of material spilled
    • The spill response action

    In the event of a spill to the environment immediately contact the BC Environmental Emergency Program at 1.800.663.3456. Provincial regulations may require notification for spills as small as 1 litre depending on the substance. Keeping a spill kit on hand to manage any accidents will ensure the health of our freshwater and marine environment.

    Add Green Stormwater Infrastructure

    Green stormwater infrastructure such as a rain garden, infiltration flow through planters or permeable paving help slow, clean and store rainwater. When rain falls in our region, it quickly moves from our roofs, streets and parking lots to storm drains that enter local waterways and shorelines. This intense runoff grows in volume and picks up various pollutants along the way including oil, metals and bacteria. By adding green stormwater infrastructure around your parking lot, you can reduce the rainwater and pollution entering your catch basin and cleaning requirements. Learn more >>

    Evaluate Waste

    To properly determine whether a catch basin contains hazardous waste, expensive laboratory analysis is required. However, there are clues that give an indication of whether catch basin waste may be hazardous:

    • Oil and grease sheen
    • Discolouration
    • Surface staining around
    • Unusual odours (like gasoline or oil)

    If indicators are present, a hauler should treat the waste as hazardous to save the costs of laboratory analysis. Be aware of and prevent collection of liquid waste from any nearby pollutant sources (fuel stations, vehicle servicing facilities, industrial areas, recyclers, scrap yards, electrical transformers, etc.). If the waste is hazardous, the hauler is required to hold or obtain a license from the BC Ministry of Environment & Climate Change Strategy to transport it. A Hazardous Waste Manifest Form must be completed and distributed to the ministry, the waste generator, the waste hauler and the waste receiver.

    Located on the Saanich Peninsula?

    Properties in Central Saanich, North Saanich & Sidney must follow the Saanich Peninsula Stormwater Souce Control Bylaw No. 4168:

    • Inspect your catch basin every three months to verify floating oils and solid levels.

    • Floating oil and grease, and settled solids cannot accumulate to more than 75% of the designed capacity.

    • Use a certified hauler to clean out the catch basin yearly right before the fall rains in September or October.

    • No chemical agents, solvents or hot water can be used to help oil, grease and solids to move through the catch basin.

    • For full details, check out Schedule "C" of Bylaw No. 4168.