Private Sewer Lift Station and Ejector Rules by Valley City

Arizona's Type 4.01 General Permit, A.A.C. R18-9-E301, has three triggers, and any one is enough: a system that serves "downstream from the point where the daily design flow is 3000 gallons per day," "A sewage collection system that includes a manhole," or one "that includes a force main or lift station serving more than one dwelling." The last one says dwelling, so a commercial station is usually caught by the first two: the private sewer feeding it has manholes, or the flow passes 3,000 gallons a day. Construction waits for a Construction Authorization, and the station can't discharge until ADEQ issues a written Discharge Authorization (R18-9-A301).

The lift station rules set a floor every Valley city builds on:

• Two pumps. "Equip a lift station wet well with at least two pumps," with design flow met "with any one pump out of service."
• Alarms. High or low wet well levels trigger an alarm "at the wet well site and at the system control center."
• Standby power over 10,000 gallons per day. Plus redundant level controls.
• Odor and retention. No more than 30 minutes of retention in the wet well unless the sewage is aerated, chemically treated or ventilated.
• Floods and security. Nothing in a floodway, protection from the 100-year flood, and a sign with the owner's 24-hour emergency number.

• Lift station. A wet well and pumps that push sewage through a force main to a higher gravity sewer.
• Sewage ejector. A smaller pump system inside or beside one building, usually for a below-grade restroom or floor. It's building plumbing under the city's plumbing code.
• Force main. The pressurized pipe from the pumps.
• Duty and standby pumps. One pump runs; the other waits to take over. Scottsdale writes it as "one (1) duty + one (1) standby."
• Telemetry or SCADA. Remote alarms that call someone when a pump fails or the wet well rises.
• Public right-of-way and easements. City land and utility strips. Mesa, Gilbert, Avondale and Chandler keep private sewer facilities out of them.

Developers, owners and HOAs with a private lift station on a sewer system that has manholes or passes 3,000 gallons a day: business parks, shopping centers, apartment complexes and campuses. Property managers running an existing station inherit the O&M manual, the alarms and, in Gilbert, the yearly records.

This usually does not cover a single building's ejector pump. There, the city's adopted plumbing code controls. The state's single-building exception is written for gravity lines, though, so a large building pumping past the 3,000 gallon point should check with ADEQ. Scottsdale's manual adds that ejector systems "are to be owned, operated and maintained by the property owner."

A Mesa flex park below the sewer. The engineer designs a private duplex station on the owner's parcel, outside any public easement. It's built to the state rule and the adopted plumbing code, and the owner keeps the alarm contact and O&M manual current.

A Scottsdale mixed-use project. The team's first step is a pre-design meeting with Water Resources. If the city will own the station, it sits on a tract deeded to the city; if it stays private, the city recommends the same design criteria in case it's ever asked to take it over.

A Gilbert shopping center's station fails an alarm test. The town expects the yearly O&M records, so the missed check shows up on paper.

A restaurant adds a basement prep area. The answer flips: a small ejector for one building isn't a 4.01 collection system. It goes through the city plumbing permit instead.

1. 1Decide which setup you have. One building's ejector goes to the plumbing permit; a multi-building station goes to ADEQ and the city.
2. 2Book the city meeting early in Scottsdale, Peoria and Gilbert, and get the City Engineer's approval in Chandler and Mesa.
3. 3Keep the station off public right-of-way and easements where the city says so.
4. 4Have an Arizona-registered engineer design to R18-9-E301 and the city manual, then file the Notice of Intent. In Maricopa County, the county Environmental Services Department issues the Approval to Construct.
5. 5Keep the O&M manual, alarm contacts and maintenance records for the life of the facility, and send Gilbert its yearly records.
6. 6Test the alarms and swap the lead pump on a schedule so the standby pump actually runs when needed.

• "Private means unregulated." ADEQ's 4.01 covers private systems, and cities review them too.
• "A big single pump is enough." State and city rules all ask for at least two.
• "The city will take it over later." Phoenix and Scottsdale warn that private stations may need upgrades if the city is ever asked to assume them.
• "An ejector is a small lift station." For permits, it's building plumbing, not a collection system.
• "The ejector line can run down the street to a neighbor's connection." Scottsdale doesn't support private pressurized ejector lines across neighboring frontages.

Under R18-9-A301, construction can't start before the Construction Authorization, and the station can't discharge before the Discharge Authorization. Several cities won't accept a private station on public land at all, so a station in the wrong place gets redesigned before approval.

Lift station design and permitting belong to a registered civil engineer. When sewage backs up into the building, clearing and camera-inspecting the building drain and sewer lines is plumbing work, and HQ answers those calls 24/7.