Grease Interceptor Lid and Riser Repair

The lid has to open for every pump-out and carry whatever drives over it. That sounds basic, and it is where tanks get neglected, because a lid is the one part everybody can see and nobody inspects. Between the tank and the cover, risers made of stacked grade rings bring the access up to grade. If the cover or rings fail, the tank fails its access duty even when everything inside is perfect.

The codes are clear on both halves. Phoenix wants interceptors free from obstructions and readily accessible. Scottsdale quotes the plumbing code: access shall be provided to each interceptor for service and maintenance. Mesa wants easily removable covers, and traffic rated ones.

These are the ones we see, roughly in order of urgency.

• A cracked or chipped cover in a drive lane or parking stall. Traffic makes it worse every day.
• A cover that rocks or is not seated after the pump truck leaves. A loose cover is a hazard for cars and people, and it lets debris and water in.
• A sunken ring or settled pavement around the lid. Gaps open up at the joints.
• A lid you cannot find. Paved over, striped over, or buried under a dumpster pad or planter. If a pumper cannot open it, it will not get pumped.
• Odor around the lid. Mesa requires bolted covers to be gastight and watertight.
• A man-way that is too small to enter, which matters because Phoenix sets 20 inches inside diameter as the minimum.

If you suspect the damage extends inside, the next step is an inside inspection. Water and grit that reach the tank through a broken lid are not good for it either.

HQ looks at the covers, the grade rings and the access path as part of any interceptor visit. Depending on what we find, the work is one or more of these.

1. 1Cover replacement with a unit that matches the traffic above it, per the tank maker's specs and your city's wording rules.
2. 2Resetting or replacing grade rings that have shifted, with shrink-proof grout in the joints, which is what Phoenix's code requires.
3. 3Adding or adjusting a riser to bring a deep or buried lid to grade, so the pumper can reach it. See when a riser or extension collar is needed.
4. 4Clearing the access. We tell you what is on top of the lid, and you or your landlord move it.

Paving, saw-cutting and heavy slab work around a lid can need other trades or a right-of-way permit if it reaches the street. We tell you that up front, in the estimate.

The word on a plan does not carry the load. The rating is cast into the cover and frame, and the tank's slab and risers have to match it. The precast industry says all interceptors should be designed for traffic loading, at minimum to ASTM C890. So ask for the rating by standard name from the maker's submittal, ask the tank maker what the slab and risers are rated for in that spot, and ask the city whether it expects a specific rating. Our page on whether a grease interceptor lid needs to be traffic rated explains the terms.

Mesa adds a rule that catches people: its covers must not be marked as owned by the City of Mesa. Check that on the order before the casting is made.

Do not pay for a new cover if the old one is sound and just needs to be seated, cleaned and unblocked. Do not pay for riser work if the real problem is a dumpster parked on the lid. And do not use a lid fix to answer a grease problem: lids and risers do not stop grease from leaving the tank. For that, see baffle repair and tee and standpipe repair.

If the tank is under a lot that is about to be repaved or restriped, tell us before the crew arrives. It is easier to raise or protect a lid before the asphalt goes down than after.

Tell us the city, where the tank sits and what you see on the lid. We offer free estimates, an upfront price before work starts and 24/7 emergency service. Related: grease trap and interceptor service, restaurant plumbing and property management plumbing.