Follow the station's O&M manual first. EPA's guidelines give a sound baseline: check alarms and lights weekly, take pump amp readings monthly, inspect pumps and clean floats quarterly, and pump out the wet well, check valves and inspect the electrical controls at least twice a year. Heavy grease or wipes mean more often.
The baseline schedule
EPA's 2022 guidance on collection systems and lift station maintenance lists specific intervals. Here they are in one place:
| How often | Task (per EPA's guidelines) |
|---|---|
| Weekly | Inspect the lights and alarm system |
| Monthly | Take amp readings on each pump motor |
| Quarterly | Inspect submersible pumps and impellers; clean and inspect floats |
| Twice a year | Pump out and clean the wet well; inspect check valves; inspect all electrical motor control equipment |
| Every visit | Log motor hours, dates and work done |
EPA frames its routine the same way at a higher level: daily reports and alarms from remote monitoring, a weekly inspection, a monthly visual inspection and semi-annual maintenance.
Each task has a reason:
- Weekly alarm check. EPA says "an alarm system in working order can alert you to problems immediately." An alarm that has quietly failed gives no warning at all.
- Monthly amp readings. If readings don't match the maker's specs, EPA says "it is an indication that rags or debris could be lodged in the impeller." It's the cheapest early warning a station has.
- Quarterly pump and impeller checks. EPA adds a trigger: inspect the impeller whenever "motor hours are not within 10% of each other" (EPA lift station guidelines). Two pumps should share the work, so a big gap in hours means one is struggling or not running.
- Quarterly float cleaning. EPA says "the buildup of grease prevents floats from working properly." A stuck float can keep a pump from starting when it should.
- Twice-yearly wet well cleaning. EPA says wet wells "should be pumped out and cleaned at least twice a year, or more often if necessary," because solids and grease build up, and that build-up "can create odors and damage the pump."
- Twice-yearly check valve inspection. This keeps sewage in the force main from draining back into the wet well.
- Twice-yearly electrical inspection, to find poor connections and worn parts in the motor controls.
EPA also recommends an hour meter on each motor and "a logbook of motor hours, dates and maintenance performed." That log is how you spot a pump that's wearing out before it quits.
What Arizona requires of the owner
For a station permitted under Arizona's sewage collection system rule, A.A.C. R18-9-E301 (the ADEQ 4.01 General Permit), maintenance is not optional. The owner certified that an O&M manual exists before the station went into service, and the rule says the permittee must operate the system "using the operation and maintenance manual" to meet its performance standards. Those standards include preventing releases of sewage to the ground and providing "adequate inspection, maintenance, testing, visibility, and accessibility."
The rule also requires operation under Arizona's operator certification rules and says to follow "all applicable state and federal confined space entry requirements" when working on the station. So the schedule above is work for a trained crew, not a building engineer with a flashlight.
### Who should do the work
A wet well fits OSHA's definition of a confined space: large enough to enter, with limited ways in or out, and not designed for anyone to stay in. OSHA's examples include vaults and pits. Because sewage can produce a hazardous atmosphere, a wet well is usually a permit-required confined space, which brings air testing, training and rescue planning for anyone who goes in. EPA's guidance lists the same safety basics for this work: lockout and tagout of electrical, water and pneumatic systems, confined space permitting and training, and de-energizing equipment before touching it.
For owners, that sorts the tasks into two groups. Anyone on site can look at the alarm panel, note pump run lights and write down what they see. Pulling pumps, cleaning the wet well and working inside the control panel belong to a trained operator or service company.
### What a good service visit leaves behind
Ask for a written report after every visit. At minimum it should show the date, amp readings for each pump, motor hours, the condition of the floats and check valves, and anything replaced. Compare it to the last report. Hours drifting apart, amps creeping up or a float cleaned every visit are the signs that tell you to act before an alarm does.
### Standby power needs its own schedule
Stations averaging more than 10,000 gallons per day must have a standby power source and redundant level controls under the same rule. A generator that isn't exercised and fueled isn't really standby. EPA lists generator maintenance and diesel fuel treatment among the maintenance items for a station, alongside check valves, air release valves, odor control systems and the control panel.
### Don't forget the force main
EPA's guidance calls out air release valves on the force main as "often forgotten about until the lift stations can not pump into the force main due to the pressure." Air trapped in the line makes pumps run longer. If your site has them, put them on the list.
Smaller ejector systems inside a building
A sewage pump that lifts waste from a basement restroom is a smaller cousin of a lift station. The plumbing code doesn't set a service interval for it, but it does say the level control "shall be adjusted and maintained" so sewage never rises within 2 inches of the inlet pipe (IPC 712.3.4). In practice, follow the pump maker's manual, test the alarm, and have the pit and floats cleaned when you see grease or rags building up. The same EPA logic applies at a smaller scale.
What makes a station need service more often
EPA's "at least twice a year" is a floor. Plan on more often when:
- Restaurants or food service feed the station. Grease coats floats and walls fast. A working grease interceptor upstream is the best defense, and our page on how often to pump a grease trap covers that side.
- Wipes are getting flushed. EPA lists flushable wipes among the causes of sewer overflows, and they wrap around impellers.
- The station runs long cycles or frequent alarms. That's a sign of wear, debris or a capacity problem.
- Odors show up around the station, which can point to solids building up in the wet well. EPA ties that build-up to odors directly.
Build it into your maintenance plan
Put the lift station on the same calendar as your backflow tests and water heater service. Our guide to a commercial plumbing preventive maintenance plan shows how to organize it. If an alarm does go off, what a lift station alarm means and what to do covers the first steps, and sewage lift station basics explains the parts.
Keeping the lines feeding the station clear is part of the job. HQ Plumbing and Air can camera and hydro jet commercial drain and sewer lines 24/7, with the price given up front before work starts.