Sewage Smell in Converted Home Now a Restaurant

Quick Column Summary:

• Sewage smell in yard
• Plumbing was cleaned out
• City sewers are clear
• Find problem with peppermint oil test

Deb Schwartz, who runs a restaurant in Eagle Rock, CA, has a perplexing problem with a sewage odor in here Craftsman house that's now a restaurant. Let her tell you all about it:

"We bought a restaurant about a year ago which had been an old Craftsman House built around 1911.  It was converted to a restaurant about 7 years before we bought it.

We noticed pretty early on when we opened that there is a horrible smell of either rotten eggs or sewage at various and random times in our back yard and back parking lot.

We have had the smoke tests done, we have hydro jetted our plumbing, we have had our grease trap completely cleaned out and we have had the City out to check the City sewer lines.  All seem to be either fixed or not broken - but we cannot get rid of the random and horrible smell!

I am starting to wonder if the previous owner of the restaurant had an illegal grease trap installed, and therefore no amount of cleaning or checking the grease trap will fix the problem because it needs to be rebuilt? We are at a complete loss as to what to do.

The City tells us adamantly that the City Sewers are clear and clean. Our plumbers tell us that our plumbing is clean and clear and that the smoke test shows no leaks.  What would you suggest we do next?  We have to find and fix this problem, and we don't know where to turn at this point."

Here's my advice to Deb:

Deb, you need to do the peppermint oil test. CLICK HERE and buy at least 4 ounces of peppermint oil. Get the best stuff. You may need 8 ounces.

When the restaurant is closed and NO WATER is being used in your plumbing system, pour 4 ounces of this into one of the roof vent pipes. Then pour about a quart of water into the vent pipe to get the oil to travel down into your drainage system. The smell of peppermint is very powerful - especially if you get the great stuff. It's often better than a smoke test.

If you smell peppermint INSIDE the restaurant, then you know you have a leak somewhere in your drain or vent pipes.

The most COMMON location for a leak like this is at a toilet. Even though a toilet is secure to the floor, the wax seal can be faulty.

Let me know what happens.