Interceptors

Interceptors are used to prevent particles, such as sand and grit which are more dense than water, and Liquids, such as oils and solvents, which are lighter than water, from entering the storm, water system.

The heavy particles of sand and grit sink to the bottom of the interceptor to form a sediment as the flow gradually moves through the tank. Oils are generally lighter than water and so move to the surface and are unable to leave the tank due to the baffle plate across the exit.

Interceptors are fitted on the runoff from motorways and should be fitted to the storm water drains of companies where there is a significant possibility of particles or chemicals entering the storm water system. Because storm water drains usually lead directly back to rivers or lakes any contamination of the storm water is potentially very damaging.

Regular inspection and emptying (removal of oil and sediment if required) of interceptors should be properly recorded.