Drain interceptors are a defence to stop contaminants from entering surface water drains.
Also referred to as petrol interceptors or oil interceptors, they are made up of tanks installed within drainage pipework designed to collect and keep hold of contaminants, such as petrol and oil that wash into the surface water drain during rainfall or when washing vehicles.
They’re most often used in industrial settings or commercial premises such as petrol stations or car parks, where waste like oil or petrochemicals are frequently spilled on the ground. They can also be found at production or manufacturing sites and at storage facilities, where other fats, oils and grease (FOG) are also at risk of entering and contaminating surface water drains.
At Willow Pumps, we can support with the ongoing maintenance and servicing of drainage interceptors.
Why are Drainage Interceptors Important?
Oil interceptors or petrol interceptors are vital in wastewater management systems, as they play a huge part in protecting the environment.
They act as barricades to stop pollutants entering water sources including streams, rivers, lakes and seas – water which is consumed by humans and animals. Having an interceptor prevents water contamination and makes sites compliant with Environment Agency regulations. Often, environmental authorities will actively request that drain interceptors be installed in high-risk areas where likeliness of contamination is greater.
How Do Drainage Interceptors Work?
- Petrol interceptors and oil interceptors work via a series of tanks or chambers installed within drainage pipework.
- Surface water from roads or car parks flows into the first chamber, which is vented to effectively remove any odours or gases.
- As wastewater enters the drain interceptor it becomes separated; fats, oils and grease float to the top because their density is lower. Solids settle at the bottom. Clean water stays in the middle of the tank and exits the interceptor on its way to the sewer system or another designated outlet.
- Any contaminants that have been captured are removed from the interceptor drain using methods including pumping, skimming or manual cleaning depending on the tank size.
Is a Drain Interceptor the Same as an Interceptor Trap?
No. Interceptor traps are devices that were originally introduced during Victorian times as a way of preventing the spread of airborne diseases. The traps were said to significantly reduce smells emanating from main sewers back into properties and were installed widely in drainage systems during this period.
Who’s Responsible for Servicing Drainage Interceptors?
If you’re the landowner of your site, it is your responsibility to prevent pollution from occurring, so routine sampling, maintenance, and servicing of your oil or petrol interceptor are vital.
If you don’t own the site, it would be the responsibility of the landowner, or a third party they’ve employed, to carry out site-wide maintenance.
How Often Should Drainage Interceptors Be Serviced?
Maintenance is key to having a functional drain interceptor system. Without due care, the interceptor will lose its effectiveness and could cause unexpected flooding leading to costly emergency call-outs. They should also be regularly maintained to ensure your site remains compliant with environmental regulations.
The Environment Agency recommends that interceptors be emptied every six months, but this isn’t compulsory guidance. If you work from a heavy commercial or industrial site, we recommend having your drainage interceptor services every six months. Drainage interceptors on sites such as car parks can be serviced annually.
What Happens if You Don’t Service a Drain Interceptor?
If you fail to properly maintain and service a drain interceptor, it will become less efficient over time and once it reaches capacity, will be ineffective in separating pollutants from wastewater. This could lead to blockages in pipes, risking flooding and emergency, costly repairs which would also cause disruption to your site.
There are also serious legal implications for businesses which are found not to be complying with their environmental obligations, including both an unlimited fine and a criminal offence, with the potential for imprisonment.
Drain Interceptor Servicing from Willow Pumps
Willow Pumps’ drainage division has a network of highly trained engineers and a fleet of tankers available to service drainage interceptors.
Contact Willow Pumps today to find out more about drainage interceptor servicing and maintenance, to ensure your interceptor remains operational and functioning at its full potential.
