08-07 Grease interceptor

Question: 08-07Code Section: 7Date: 10 February 2008OBC 2006 Reference:,

Question submitted: I have a restaurant on a private sewage system which had a grease interceptor under the sinks and obviously the owner did not empty it on a regular basis. The outcome — a new sewage system was ordered by the Health Unit. A large cement grease interceptor was installed outside the building and I had to inform the owner that all fixtures discharging fat or grease had to go through it. During my inspection, I have discovered that even sinks not containing grease or fat have been directed to that new grease interceptor (cooling compressor drain, potatoes washing sink, hand washing sink). Would that be considered a “no no”? The code does not say; Only fixtures containing fat or grease shall discharge through a grease interceptor. Or did I missed something somewhere? Is there some flexibility on this (moderate volume of water allowed)? I am sure the size of this interceptor is large enough to handle this extra water being discharged in.

Interpretation: The intent is that only fixtures that discharge, fats, cooking oils or grease should discharge through a grease interceptor, re; The Code is silent on specifying if plumbing fixtures, other than grease bearing discharge fixtures, may discharge through a grease interceptor in order to keep the size of an interceptor within reason. The key word in the equation is fixtures, approval should be sought from the Health Unit and an Engineer should verify that the sizing and other requirements, meet Part 7. Nothing is preventing all fixtures within the kitchen and discharging them through the interceptor. and (7) need to be looked at for installation compliance.

Interpretation: Approved at AMES 2008