Full Interceptor Service vs Emptying my Interceptor: What’s Best?

Traditional interceptor management usually involves regular emptying of interceptors.  This means that everything is emptied out of the interceptor and removed as a hazardous waste.  This can get quite costly so is there an alternative?  Read on to find out more.

What is an interceptor?

Interceptors, sometimes called separators, are large underground tanks that are fitted on the drainage system to separate oil from water.  They also allow silt to settle out and sink to the bottom.  Interceptors are designed to prevent oil from leaving and causing pollution off-site.  They can be found on both surface and foul drainage systems and are often located in areas of high risk (e.g. vehicle wash, fuel island) and/ or on the outflow from the site.

Why do interceptors need maintaining?

As water passes through them, interceptors accumulate oil at the top and silt at the bottom of the tank.  As they fill up, contamination can escape and cause pollution, therefore, regular servicing is required.  Service visits should ensure that oil and silt is not allowed to build up and identify any potential structural issues or damage requiring attention that could compromise the effectiveness of the interceptor.

How is traditional interceptor management carried out?

Historically, interceptors are regularly completely emptied out with a tanker, removing all water, oil, silt and other contamination; usually every 6 months or annually.  This type of management does not take into account the levels of contamination and the whole load will usually be classified as hazardous waste.  This can be a costly exercise taking into account the site visit, carrier charge and the cost of waste disposal.  Additionally, you will need to make sure that the interceptor is filled up again with clean water or it won’t work properly as a pollution prevention device.

What can I do instead?

Although it may occasionally be necessary, it isn’t always essential to empty your interceptors.  They should receive a regular maintenance visit (6 monthly or annually) and be checked for any issues or damage and to assess the level of oil or silt contamination.  Where contamination is present, it will probably be removed, but the interceptor can be topped and tailed, leaving behind the non-contaminated water.  This will reduce costs as you will be carrying and disposing of much less waste.

If your interceptors have not been serviced for a long time, you may need to remove all of the contaminated water and fill with clean water.  However, after that, or if they are in good condition with little or no contamination, you should not need to empty your interceptors every time they are serviced.  It is essential that you regularly service your interceptors (remind yourself why here) to ensure they continue to offer pollution protection by collecting oil and stop it from leaving site.  However, it is not essential to completely empty an interceptor during every maintenance visit and more informed interceptor visits could save money while maintaining pollution management.