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Oil separator maintenance

Compliant inspection, maintenance and repair of your separator and alarm.

We help operators of sites with oil storage remain compliant with current legislation by inspecting, maintaining, and repairing your separator and alarm so that you can reduce the risk of an environmental incident, regulatory fines, operational downtime, and reputation damage.


The current standard by which separators should be operated and maintained, is BS EN 858-2:2003 Separator systems for light liquids (e.g. oil and petrol), it states separators should:

  • Be fitted with an automatic warning device/high level alarm.
  • Be serviced and maintained as a minimum on a 6 monthly basis.
  • Be subject to a maximum interval of a 5 yearly integrity test.
  • Have full service and maintenance records available for inspection.

What do you get?

  • Receive a full report following all separator inspections.
  • Our thorough inspections extend the lifespan of your assets.
  • Fully compliant 6 monthly and 5 yearly inspections.
  • Compliant service and full maintenance records provided for inspection.
  • We fully manage disposal of any hazardous waste removed during maintenance.

6 monthly inspection

First we will check and report on the liquid level inside the separator against the manufacturers specification based on its size and capacity using a drain rod. This will ensure that the water level is above 10mm and identify any issues.

If there is a high liquid level it could mean that the filter is blocked, there is a problem with the outfall or something is stuck in the pipework. We can remove excess liquid using our vacuum tanker.

The drain rod will also help us to identify how much silt is inside the tank. If the silt level is too high we will use our vacuum tanker to remove the grey water first and apply bungs to stop it going back into the separator. At 120 mm from the bottom we will use water to uplift the silt and wash down the tank before partly refilling the separator with the grey water backed up with the inlet surface water drainage.

We will check the oil level using a baler. If more oil is detected, we recommend this is skimmed off at the next maintenance visit.

We will manage and dispose of any liquid, oil or silt waste removed from site compliantly.

If the filters are blocked these can be jetted or replaced to ensure liquid can move freely through the separator.

Verify that the alarm system is operational.

Coalescing filter

Once the above checks have been performed we will then inspect the coalescing filter to ensure it is operational. We will then jet it down to ensure it is operating at its optimal capacity.

If the filter needs replacing we would add this to our report and suggest it is replaced at our next visit.

5 yearly inspection

This inspection is more detailed than the 6 monthly and involves completely emptying the separator to perform a full integrity test.

Our confined space entry qualified engineers will visit your site to:  

  • Inspect the inlet pipe.
  • Make sure the closure device is fully operational.
  • Ensure the docking station is secured to the base.
  • Inspect the outlet pipe from the docking pipe to the outfall is fully secure.
  • Check it is holding water.
  • Inspect the filters.

If confined space entry is not feasible we can use our CCTV camera equipment to identify surface cracks, fractures, displacements, and collapsed systems.

There is potential for rubble to get into the docking station and this should be cleaned out.

At this inspection we can find fractures in tank which we can repair using our GRP lining product.

Separator alarm and control panel

We will validate that the control panel is operational, and your separator alarms are working. Your alarms are connected to your GSM systems we will ensure these are operating correctly and alerts and alarms are reaching the correct person.

Some alarms are run by solar or battery. We will test the strength of the battery and ensure the sure solar power is fully operational.

Service and maintenance records

Our experts will ensure full and compliant service records are given to you on the same day as the visit to ensure that you comply with BS EN 858-2:2003 in the event of an environmental incident.

Keep your business compliant and protect the environment while reducing the risk of operational downtime

Find out how Adler and Allan reduce your risk and support you on your journey to Net-Zero through the management and maintenance of assets.

Contact our experts