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The Interval Is Not a Number We Can Give You

This is the question everyone arrives with, and the honest answer is a method rather than a figure.

The short form

There is no national pumping interval. Where one is enforceable it is set by your control authority in its sewer use ordinance, and otherwise the right frequency depends on the vessel’s working volume and what the kitchen puts through it. Two identical vessels can need entirely different schedules.

Source: 40 CFR 403.5, National pretreatment standards: Prohibited discharges.

InterceptorCall is a referral service, not a contractor. We connect operators and property managers with independent contractors. Contractors and waste haulers are required to hold whatever credential and permit their state or municipality demands — ask to see them, because the manifest they leave you is a compliance record. We carry out no work, we haul nothing, we do not set prices, and we never charge the caller anything. Nothing here states the grease limit, the pumping interval or the device size that applies to any particular kitchen; those are set by your control authority and by your installation.

Why no figure appears on this page

Because the enforceable interval, where one exists, is set by your control authority in its sewer use ordinance, and because the right interval for a given vessel depends on what it is, how big it is and what the kitchen puts through it.

Printing a number would give you something to point at that has no standing wherever you actually are. The rule that binds you is local.

Source: 40 CFR 403.5, National pretreatment standards: Prohibited discharges.

What genuinely drives it

Volume of cooking, and the kind of cooking. A fryer-heavy menu loads a vessel faster than a salad-heavy one. The device’s working volume, which is not its total volume but the band left between the floating layer and the settled one. And whether anything upstream is sending grease it should not.

Two identical interceptors behind two identical buildings can need entirely different schedules.

A working vessel is not necessarily a compliant one

EPA’s training material carries a case worth knowing: a 2,000 gallon interceptor, pumped every two months, with correct inlet and outlet tees and a baffle wall, still discharging heavy grease downstream. The pumping schedule was not the problem — something else in the connections was.

So frequency is one variable among several, and a vessel that is emptied on time can still be failing. The failures that are not about the schedule.

Source: U.S. EPA, FOG Management and Control Program.

How to find your actual answer

Ask your control authority for the FOG program requirements for your classification. Ask whether the interval is fixed, or set by a condition such as accumulated depth, or determined by inspection. Ask what they want to see in your records.

Then ask your service contractor what they are finding when they pump, because that is the evidence for whether the interval is right.

And the thing worth measuring yourself

How much comes out each time, recorded on the manifest. A volume that is climbing service to service means the kitchen is loading faster than it was, and that is a signal well before it is a violation.

What the manifest is and why it is kept.

Have the last manifest in front of you.Date, hauler, volume removed and where it went — it is the first thing anyone asks for and it tells a contractor more about the state of the vessel than a description does. We will route you to somebody who covers your area, identified from the ZIP code of the premises, and you are never charged. Other plumbing work at the premises can be arranged through the same call.

Call (888) 753-1770