Septic systems in Delaware and Union counties: the basics
Outside the sewered parts of Delaware, Marysville, Dublin and Powell, thousands of homes in Delaware and Union counties rely on private septic systems, which Ohio calls household sewage treatment systems. That ranges from older tank-and-leach-field systems on farm-country lots to aerators, mounds and drip systems in newer rural subdivisions. The soil is a big reason the systems vary so much. Summaries of USDA soil data rate the large majority of Delaware County's mapped land as very limited for conventional septic absorption fields, mostly because of slow-draining glacial clay and seasonally high water tables.
Ohio's 2015 sewage rules, and what they mean for you
On January 1, 2015, new statewide sewage rules (Ohio Administrative Code 3701-29) took effect. Two parts matter most to homeowners:
- Operation permits and O&M programs. Local health districts must run an operation and maintenance program so systems get evaluated periodically. Records from O&M inspections must be provided to the board of health within 60 days.
- Registered contractors. Septage haulers, service providers and installers must register with each local health district where they work. Registration requires passing the Ohio Department of Health exam, at least $500,000 of liability insurance, a statewide surety bond, and continuing education.
Delaware County at a glance
The Delaware Public Health District (DPHD) runs the O&M program for the county. According to DPHD:
| System type | O&M permit length |
|---|---|
| Septic tank plus leach field (no pump) | 5 years |
| Systems with mechanical parts: aeration tanks, mounds, drip distribution, pump stations, discharging systems | 1 year |
There's currently no charge for the DPHD O&M permit itself. If a registered service provider doesn't submit a report and the district has to do the evaluation, there's a maintenance inspection fee ($75 on the 2025 fee schedule). DPHD has been phasing existing systems into the program, south to north, and expects all known systems to be enrolled by about 2028. In practice, a registered contractor services your system and sends in the report, and you avoid the district's inspection fee.
Union County at a glance
The Union County Health Department issues operation permits on a five-year cycle, at $50 ($10 per year). The current cycle covers 2025 through 2029, and unpaid renewal fees can be added to property taxes. Many systems, such as those with aerators or that discharge, need an annual inspection. Homeowners can meet that by keeping a contract with a registered service provider, registering to service their own system, or having the health department inspect it.
How often should a septic tank be pumped?
The traditional advice is every 3 to 5 years. DPHD's O&M materials cite Ohio State University data suggesting a typical three-bedroom home with three occupants needs pumping roughly every 5.9 years. Bigger households, garbage disposals, water softeners discharging into the system and smaller tanks all shorten that interval. Aerators and other mechanical systems also need regular service under their permit conditions, not just pumping. The safest answer: have the sludge and scum layers measured during service, and pump when they say so.
What pumping costs
HomeGuide lists typical septic tank pumping at $300 to $700, and $500 to $1,000 with additional cleaning. Larger tanks, digging to find buried lids, long hose runs and extra compartments add to the price. Installing risers so lids are at ground level saves money on every future visit.
Warning signs not to ignore
- Slow drains or gurgling throughout the house, not just one sink.
- Sewage odors in the yard or house.
- Soggy ground, bright green grass or standing water over the leach field.
- An aerator alarm or warning light.
- Sewage backing up into the lowest drains.
How this service works
This website is a referral service, not a septic company or a government agency. When you send the quote form, we connect you with one independent septic contractor who serves your area and is registered with your county health district. They quote and do the work, and you're free to compare. Contractors pay us for referrals, so it's free for you. How referrals work.
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