How often must a Gilbert restaurant pump its grease trap? Town Code 66-244(d) and (e)

Pumping. Subsection (d) says the contents of all grease removal devices "shall be removed periodically as necessary to prevent violations of this chapter." Then it sets the floor: "At a minimum, the entire contents shall be removed every six months, or more frequently as needed to prevent carry over of grease into the POTW." The one way out is that the director can accept a longer interval if you demonstrate it works to the director's satisfaction.

Additives. Subsection (e) covers biological or chemical additives. If you use one, you remain responsible for keeping the device effective, and you must notify the director and provide the safety data sheets. Using additives alone "is not considered an acceptable maintenance practice", and they cannot be the sole method of treating or maintaining the discharge. Emulsifiers are prohibited in grease removal devices, and using them to cut how often you pump is expressly prohibited.

Records and access. Section 66-243(d) says pretreatment devices must be kept in continuously efficient operation at the owner or operator's expense. Written records of cleaning, repair, calibration and maintenance stay at the facility for at least three years and go to the director on request. The device must be easy to reach for cleaning and inspection.

• Entire contents: the whole volume in the device, not a skim of the grease cap. Our reading is that a partial pump-out does not meet the six-month minimum.
• POTW: the publicly owned treatment works, the town's sewer collection and treatment system.
• Emulsifier: a product that breaks grease into small droplets so it flows out with the water. Gilbert bans it in grease devices.
• Additive: a biological or chemical product added to help the device work. Allowed as a supplement, with notice and data sheets.

Every owner or operator with a grease removal device in Gilbert. That includes restaurants, schools, grocery and convenience stores and the other food service facilities the town lists. Haulers do the work, but the code puts the duty and the paperwork on you.

A busy grill on a six-month contract. The hauler pumps in March and September and leaves a manifest each time. The manager files it in one binder. That meets the minimum, but if the line runs slow in July, "more frequently as needed" means an extra pump-out.

A bakery with a light fryer load. The owner wants to skip a service. The code allows a longer interval only if the owner demonstrates it works to the director's satisfaction. The safe move is to ask first and get the answer in writing.

The edge case: the enzyme dosing system. A vendor installs a dosing unit and says pumping can drop to once a year. Under (e) additives cannot be the sole method, and an emulsifier cannot be used to reduce service frequency. If the product is not an emulsifier, you still notify the director and file the data sheets, and the six-month floor still applies unless the director agrees otherwise.

1. 1Check the date of the last full pump-out on your hauler's manifest.
2. 2Put the next one on the calendar, six months out at the latest.
3. 3Start a binder for manifests, cleaning notes and repair records. Keep three years.
4. 4If you use any additive, send written notice and the safety data sheets to the Town of Gilbert at (480) 503-6000 (ask for the pretreatment program), and confirm the product is not an emulsifier.
5. 5If you want a longer interval, ask the director in writing through the same pretreatment contact and show your records.

• "Pump when it smells." The code sets a six-month minimum and says more often when needed. Odor is a late signal.
• "Enzymes replace pumping." Additives cannot be the only maintenance, and emulsifiers are banned.
• "Every Valley city pumps on the same schedule." Tempe counts 30 or 90 days and Glendale 180 days. Gilbert's floor is six months.
• "The hauler keeps my records." The code puts record-keeping on the owner or operator, at the facility.