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A catering effluent problem solved

Solving blocked drains and odour problems at a restaurant

A small but popular country restaurant was experiencing blocked drains and odour problems from their service yard and in the kitchen. They had a twin basket grease trap, which none of the staff was prepared to service because the job was 'dirty' and it smelled 'bad'. The longer it was left, the worse it got and eventually the local plumber was called in. He poured a bottle of acid drain cleaner into the grease trap to clear the blocked drain from the kitchen. Far from 'freeing up' the problem, it made matters worse and the bad smell became a reek. The kitchen door had to be kept closed during the day when it was hot outside and the staff complained of the heat and lack of ventilation in the kitchen.

BIO-SYSTEMS was called in to assist and found the trap in a really filthy condition. To make matters worse, it discharged into a septic tank that was also overflowing and in a very poor state. The whole of the small service yard was grimy with old cooking oil stains and general filth all around the poorly maintained waste bins which attracted rats, cockroaches and flies. The old adage 'Dirt begets dirt' was all too evident.

CH: Monkey Valley grease trap before

Grease trap and grease trap basket before BIO-SYSTEMS treatment

CH: trap basket before deep clean

We stripped the trap and pressure cleaned the entire yard with HSDG, delivered via a pressure sprayer and stiff bristled brooms. A spade was used to pry the congealed fat off the trap casing. The twin baskets were full of congealed fat and food scraps (as the picture below shows).

Please note details of poor installation:

  1. No rodding eyes on the elbows
  2. The discharge pipe reduced to 40mm – it should have been 110mm
  3. Inadequate alignment and support strapping on both inlet and outlet lines
  4. No water tap for cleaning the trap, although the pressure line is evident
  5. Floor and walls badly maintained

We rodded all the lines, taking the outlet drain to pieces to make sure there were no lumps of fat in the pipe. A thorough clean of the whole trap and yard took over four hours, during which time we collected 5 x 15 kg bags of fat and wet waste. The trap was then rinsed with HSDG and filled with clean water into which we put 100ml of DF60 to 're-start' it. We made recommendations for the above detailed modifications and instructed the kitchen manager to use DF60 in all drain points and HSDG to wash the yard and all hard surfaces.


CH: trap basket after deep clean  After BIO-SYSTEMS treatment

The trap is now attended twice a day by the 'maintenance man', whom we trained whilst conducting the deep clean. With the restaurant's catering effluent troubles over, there is no longer any odour emanating from the kitchen and the flies have lost interest.

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