Aerator & mechanical system service
One-year permits, service contracts and alarm troubleshooting.
Aerobic treatment units, usually just called aerators, are common in Delaware and Union counties, especially on lots where the clay soils couldn't support a conventional leach field, and on systems that discharge treated water. An aerator has a motor-driven air pump that keeps oxygen flowing to bacteria that break down waste more completely than a standard septic tank. Mechanical parts mean more maintenance, and Ohio's rules treat them that way.
Why aerators need annual service
In Delaware County, the Delaware Public Health District assigns a one-year O&M permit to systems with mechanical components, including aeration tanks, mound systems with pumps, drip distribution, pump stations and discharging (NPDES) systems. Union County similarly requires annual inspections for many systems, such as those with aerators or that discharge. The rules exist because a failed aerator motor or pump stops treating sewage while everything looks fine from the house.
What a service visit typically covers
- Checking the aerator or air pump, plus its filters, diffusers and alarms.
- Checking control panels, floats and any effluent pumps.
- Looking at the effluent's clarity and odor, and sampling where required (discharging systems may need samples).
- Measuring solids and recommending pumping when needed.
- Cleaning effluent filters, and checking any disinfection unit (chlorinator tablets or UV bulbs) on discharging systems.
- Filing the service report with the health district.
Service contracts
Many homeowners meet the O&M requirement with an annual service contract from a registered service provider. In Union County, keeping a contract with a registered provider is one of the three ways to comply (the others are registering to service your own system, or having the health department inspect). In Delaware County, DPHD notes that if no registered provider submits a report, the district must do the evaluation and charge a fee ($75 on the 2025 schedule). A contract typically covers the required inspections, and some include alarm calls or parts discounts. Ask exactly what's included.
Common aerator problems
| Symptom | Possible cause |
|---|---|
| Alarm light or buzzer | High water from a failed pump or float, or an aerator motor failure, or a tripped breaker |
| Strong rotten-egg smell | Aerator not running, so the system has gone anaerobic |
| Cloudy or smelly discharge | Overloaded or under-aerated system, or a clogged diffuser |
| Humming but no air | Worn diaphragm or blocked line |
| Breaker keeps tripping | Electrical fault in the motor or pump. Call a pro, and don't keep resetting it. |
Don't turn it off
Some homeowners unplug a noisy aerator. Without air, the system stops treating sewage properly and can send poorly treated effluent into the yard or a ditch. It can also fail an inspection. If the noise bothers you, a technician can often replace worn parts or fit a quieter unit.
Electricity and alarms
Aerators run around the clock. Keep the circuit on, don't plug other things into the same outlet, and make sure the alarm is somewhere you'll actually hear or see it. Many alarms have a silence button, but silencing doesn't fix the problem.
Sources
- Ohio Administrative Code 3701-29-03 (registration of installers, service providers and septage haulers): codes.ohio.gov
- OAC 3701-29-19 (operation and maintenance management): ohrules.elaws.us
- Delaware Public Health District O&M FAQ: delawarehealth.org; permit lengths by system type: delawarehealth.org; 2025 fee schedule: delawarehealth.org
- Union County Health Department, Septic Systems and Renew Sewage Permits: uchd.net/septic-systems, uchd.net/renew-sewage-permits
- HomeGuide, septic tank pumping cost: homeguide.com
How long do aerator motors last?
That varies by brand and use. Many need rebuilds or replacement after several years of continuous running. Your service provider can track wear.
Can I service my own aerator?
In Union County, homeowners can register to service their own system. Rules differ by county, so ask your health district.
Why does my discharging system need samples?
Systems that discharge off the lot may have sampling requirements under their permit, to confirm treated water meets standards.