Why does the City clean catchbasins?
As stormwater runoff flows over asphalt, concrete and gravel on roads, parking lots, and driveways it picks up pollutants like dirt, sand, brake dust, metals, and other hazardous materials from the surface. This polluted runoff usually flows to the nearest catchbasin. When the runoff enters the catchbasin, some of these heavier pollutants sink to the bottom where they are stored. The remaining runoff drains to the storm sewer. Over time, the amount of pollutants in the bottom of the catchbasin builds up and needs to be removed.
How is catchbasin cleaning prioritized in Brampton?
The City inspects and cleans catchbasins each year to remove the stored pollutants. The inspection involves removing the grates from the surface of the road, measuring the depth of stored pollutants, and where required, removing the material using vacuum trucks. Catchbasin cleaning is prioritized in locations where more pollution is produced like in industrial and commercial areas.
Other important activities that help maintain the catchbasins and stormwater drainage system are replacing missing, damaged, or ineffective maintenance hole covers, and uncovering paved over maintenance holes.
Removing pollutants from catchbasins
Each year approximately 1500 cubic metres of pollutants are removed from City-owned catchbasins, pollutants that would otherwise end up in local rivers and creeks. These pollutants could fill the cargo bed of over 880 pickup trucks.