A Bypass Separator is a tank used in low risk areas such as a car park or roadway and they are designed to treat the first 10% of surface water runoff. The first flush from the surface is typically the most contaminated. The runoff enters the unit where any solids present sink to the bottom and are retained in the first chamber.

Oil and water are then passed through to the second chamber where they are partially separated. As rain water builds and the surface water entering the separator exceeds the design flow, further runoff is diverted to bypass the second chamber and exit the separator.

Why are Separators needed?

Separators are required when there is a high risk of hydrocarbon pollutants entering surface water drains. They are installed to protect the receiving waters from pollution.

Leaking of fuel and lubricants on all road vehicles wash into the drainage systems with the surface runoff during heavy rainstorms. Delivery vehicles and fuel depots are at particular risk of spillage.

What sizes can we supply?

A-Tanks can supply Bypass Separators ranging from 1667m2 area drained to 11111m2 area drained. Larger sizes are available on application.

Bypass Separators are sized by the area drained.