Size It Right, Set It Right, And It Stops Being A Problem

What determines the right grease trap size?

Not the space available, and not the price. These are the inputs that actually decide it.

• Total flow rate from every fixture that discharges to the trap, including the dish machine and mop sink
• Required retention time, which is what gives grease the chance to rise and solids the chance to settle
• Menu grease load, since a fryer heavy or breakfast heavy operation loads a given capacity far faster
• Peak service pattern, because a kitchen with two hard rushes behaves differently from one with steady flow
• How often you are realistically willing to have the unit serviced
• Local authority sizing requirements, which may set a floor above what the flow calculation alone suggests
• Whether the building discharges to city sewer or to an onsite septic system

Where should the interceptor be located?

Placement is the decision that owners regret most often, because it sets your service cost for the life of the building. A unit tucked behind fixed equipment, under a permanent workstation, or in a spot the truck cannot reach means every service visit takes longer and costs more, and eventually it means service gets deferred.

In ground exterior interceptors generally serve larger kitchens better. They keep the volume and the odor out of the workspace, they can be serviced with far less disruption, and they scale to capacities that simply do not fit indoors. The tradeoff is excavation and the need for access covers set properly to grade.

Small under sink units make sense for light load operations and tight buildouts, but they fill quickly and they sit in the middle of the work area. Be honest about your grease load before choosing one, because a unit that needs constant service is a daily operational annoyance rather than a background utility.

What goes wrong when an interceptor is installed badly?

Undersized units never achieve the retention time separation depends on, so grease reaches the sewer lateral even with a diligent service schedule. That is a compliance exposure and a blocked line waiting to happen, and no amount of service fixes a capacity problem.

Units set out of level separate unevenly and hold less usable volume than their rating suggests. Incorrect inlet or outlet configuration short circuits flow straight across the chamber. Missing or wrong baffles remove the mechanism entirely, and we find that on more existing traps than owners expect.

Poor placement produces the slowest failure of all, because the unit works fine and simply gets serviced less and less often until it does not. Grease trap pumping and cleaning are only effective if they actually happen on schedule, and access is the biggest predictor of whether they do.

What is not included in a grease trap installation?

Interior kitchen plumbing beyond the connection to the interceptor is a separate trade, and our sister company Afford-A-Rooter Plumbing handles that lane. Permit fees, plan review fees, and any engineering required by your local authority are passed through rather than marked up, and they are not part of a quote until the authority has told us what applies. Finish work, flooring restoration, and hardscape or landscape restoration beyond backfilling and grading the work area are outside our scope. We also do not certify compliance on your behalf. We build to what the authority requires and they inspect it.