Gilbert Town Code 66-245: floor drains and wash racks at auto shops and car washes

The section sets seven standards for vehicle and equipment service facilities. In short:

1. 1Fluids, hazardous material or rinse water from parts cleaning that reach a floor, pavement or ground surface must be cleaned up immediately.
2. 2Nobody may dispose of parts-cleaning fluids or rinse water into the sanitary sewer.
3. 3No floor drains, "excepting only such floor drains as are connected to wastewater pretreatment systems."
4. 4No tanks, containers or sinks used for parts cleaning or rinsing may connect to the sanitary sewer.
5. 5No wash rack or washing wastewater goes to the sewer unless it passes through a pretreatment device. Proper reuse of the water is not prohibited.
6. 6Cleaning must use methods that send nothing to the sewer, except wastewater that has gone through a pretreatment device.
7. 7Spill prevention and cleanup equipment and absorbent materials must be in stock and ready at all times.

Once a pretreatment device is installed, 66-243(d) applies: the owner or operator maintains it at their expense, keeps written records of cleaning, repair, calibration and maintenance for at least three years at the facility, and keeps the device easy to reach for cleaning and inspection.

• Vehicle or equipment service facility: Gilbert defines it as a commercial or industrial facility that does one or more of these things to vehicles, equipment or their parts: repair, fuel dispensing, fluid replacement, engine and parts cleaning, body repair, salvage and wrecking, or washing. That covers a quick lube, a body shop, a fueling station and a car wash.
• Pretreatment device: the town's list includes oil interceptors, sand and grit interceptors, solids traps and grease removal devices.
• Wash rack: not defined in the code. Our reading is any area where vehicles or equipment are washed and the water drains away.

Owners and operators of the facilities in the definition above. The tenant runs the shop, but the building's drains are the owner's plumbing, so a landlord filling out a tenant improvement needs to know this rule too.

A quick lube with two bay drains. The drains are not banned outright. They must run to a wastewater pretreatment system, so the plumber sizes and routes them to an interceptor. A drain that goes straight to the building sewer is the violation.

A car wash. Wash bay water goes through a pretreatment device before it reaches the sewer. The code has no size number, so the design comes from the plumbing code and the town's pretreatment staff.

The edge case: a body shop moving into an old retail space. The floor may already have drains that go straight to the sewer. Under the definition, body repair puts the shop in this section, so those drains must be connected to pretreatment or removed. Ask Development Services and the Public Works pretreatment staff before the plans are drawn.

1. 1Walk the shop and list every floor drain, sink and tank, and where each one goes.
2. 2Mark any parts sink or tank that connects to the sewer. Under the code it cannot.
3. 3For a new shop or remodel, put the pretreatment device on the plans and show every drain that feeds it, filed through the One Stop Shop portal (OneStopShop.gilbertaz.gov, Development Services at (480) 503-6700). For an existing shop, call the Town of Gilbert at (480) 503-6000 and ask for the pretreatment program.
4. 4Once the device is in, start the maintenance log: cleaning, repair and calibration, kept three years at the facility.
5. 5Stock spill kits and absorbent material where they can be reached fast.

• "A floor drain is standard, so it is fine." Not in this section. Floor drains are banned unless they go to pretreatment.
• "A parts sink can share the floor drain." Parts-cleaning sinks and tanks may not connect to the sewer at all.
• "Only car washes are covered." The definition includes repair, fueling, fluid changes, body work and washing.
• "Pumping schedules are the same as a restaurant's." Gilbert's six-month minimum is written for grease removal devices in 66-244. Scottsdale, by comparison, sets a yearly pump-out for shop interceptors on its own page.