Is your restaurant's grease trap clogged? When a grease trap starts backing up, it usually comes through either the floor drains in the kitchen or the drains in the dish pit. Depending on the reason why your grease trap is backing up, the water coming up the drain may have an extremely foul odor—this means that some of the fats in the grease trap are coming back up with it.
Regardless of where the clog is, you won't be able to operate when you can't flush anything down the drain—keeping your grease trap in top condition reduces the risk of losing revenue. Below, you'll find three reasons why a grease trap can back up, how you can fix them, and what you can do to prevent them.
Clogged Flow Rate Controller
The flow rate controller sits between the sink drain and your grease trap, and it's a vital component. A grease trap works by both cooling water and slowing it down. This allows fats, oils, and grease to separate out of the water before it exits through the outlet pipe into the municipal sewer system. The flow rate controller slows water before it even enters the grease trap, ensuring that the flow rate is low enough to give the grease trap adequate time to separate out the grease.
Unfortunately, the flow rate controller is also a common source of clogs. It's simply a small section of pipe with an air vent, so it's easy for solids or grease to build up in the pipe and block it entirely. If your flow rate controller is clogged, you'll need to call a grease trap maintenance service to remove the flow rate controller from the grease trap and remove the clog.
These clogs can often be prevented by adding a strainer to the dish pit drain. You'll trap solids before they can clog the flow rate controller.
Grease Trap Is Too Full
One of the most common reasons why a grease trap begins to back up is simply that it's filled with too much grease. Grease traps need to be pumped out when they're 25% full. In a dual-baffle grease trap (which is a common design), going above 25% full will cause grease to build up between the two baffles.
The purpose of the baffles in the grease trap is to slow the water, and it's usually moving too slowly at this point to break through the built-up grease. As a result, water starts backing up into the sink or through the floor drains in the kitchen.
Solving this problem, thankfully, is easy. You simply need to have your grease trap pumped more often. Your grease trap pumping service should tell you how much grease they removed from your grease trap, which gives you an idea of how full it was. If it's close to being 25% full every time you have it pump, you run the risk of overfilling it. Either have your grease trap pumped more often or upgrade to a higher-capacity model.
Clogged Sewer Main or Grease Trap Outlet Pipe
Finally, your grease trap may be backing up because of a clog downstream of the grease trap. You can often tell when this is the source of the clog because the odor of the wastewater backing up through your drains will be quite foul. The clog could be in either the grease trap's outlet pipe (which is easy to fix) or in your sewer main (which is considerably more difficult.) Either one needs to be handled by a grease trap maintenance professional.
Downstream clogs usually occur when too much grease is allowed to leave the grease trap. Under normal operating conditions, most of the grease in your wastewater will remain in the trap, with only a very tiny portion exiting through the outlet pipe. If larger amounts of grease escape, it can solidify on the pipe walls and cause a clog. This can happen when the grease trap isn't functioning correctly, which is why regular grease trap maintenance is important.
It can also happen if you're using additives like surfactants to break up the fats in the grease trap and flush them further into your sewer system. You shouldn't use these products—they're not a replacement for grease trap pumping.
A grease trap that's backing up into your kitchen is an unpleasant experience, but you can reduce the risk of it happening by scheduling regular grease trap maintenance service for your restaurant. When you keep your grease trap in good condition and pump it frequently, you'll avoid downtime in your restaurant due to a backup.