Have you ever entered your restaurant early the next morning after your grease trap service provider had just cleaned your trap the previous night, only to be met by the stench of a cross between rotten eggs and cold spinach, covered in vinegar? Ugh. Not a pleasant smell. It must be something the grease trap company did, right? You’re opening for the lunch crowd in three and a half hours. What do you do?
No, it's not the fault of your grease trap provider ...
... although it’s natural that might be the first thought that comes to mind. Where, then, is the smell coming from?
Over time, the seal around the manhole cover (the opening to the grease trap behind your store or in the parking area) can become deteriorated and allow gases from your grease trap to escape and waft into your restaurant from the outdoors. If that’s the case, a simple gasket repair can solve the problem.
More likely, however, it’s due to the method that was used to clean your trap.
The types of grease trap service performed may be regulated by municipalities, with some permitting a pump and return method. With pump and return, the FOG material (fats, oils, greases and solids) can be removed and taken away with the service provider, but the separated gray water is returned to your grease trap. While it may not sound logical (it's good to get rid of all the gunk, right?), pump and return is the preferred method if allowed by the governing authority, because your trap is never allowed to become completely dry.
Unfortunately, if your restaurant is in an area where only dry pumping is permitted, or perhaps that’s the only method your service partner provides (pump and return requires dedicated service vehicles to split the FOG and water), all contents of the trap must be removed – leaving your trap bone dry until you start to run liquids into it again from your kitchen. This dry environment allows gases to form, which can cause the smell that greeted you the next morning.
Check with your trap service provider and ask if pump and return is an option in your area. Because some trap service providers only operate one type of service, while your municipality may allow for pump and return, your provider may not offer it. It pays to check for a provider who can service your traps in the most efficient way that meets both your needs and your municipality's ordinances.
If you do notice an odor from your empty trap, here's what to do....
Once you've determined it's not a problem with the seal around the manhole cover, start running water in your kitchen as you would normally do. As you begin preparations for your lunch crowd, that water will begin to flow into your grease trap and in a short time the smell will dissipate as the water starts filling up the grease trap again. Another suggestion is to take a small pitcher of water mixed with baking soda and pour it down your floor drains. The baking soda will help to eliminate that odor a little faster by acting as a non-hazardous "filter" pulling out that foul smell. And if a full pump service is the only option you have, ask your provider to clean your trap soon after closing, so there's extra time for any odor to dissipate.
For reliable, professionally-serviced grease traps, with fleet options that can provide for any municipality's restrictions, DAR PRO Solutions offers nationwide grease trap maintenance in addition to their used cooking oil removal services.