Septic system requirements in Hardin County, Ohio
The septic rules landplan.io applies in Hardin County, what a septic tank costs there, and the parcel data we hold.
Updated
Design a septic system for an address in Hardin County
Ohio's state rules apply in Hardin County: landplan.io has no county rules of its own here. State rules: Reviewed See Ohio's rules
Septic systems allowed in Hardin County
The system types landplan.io permits in Hardin County:
- Mounded Leaching System
- Spray Distribution System
- Low Pressure Pipe System
- Drip Distribution System
- Leaching Trench System
- Infiltrator Advanced Treatment Leachfield (ATL)
- Infiltrator Advanced Enviro-Septic® (AES)
- Discharging System
Septic tank size in Hardin County
The daily design flow of a home: 120 gal/day per bedroom, at least 240 gal/day. The septic tank is sized from that flow:
| Daily design flow | Minimum tank |
|---|---|
| up to 240 gal/day | 1,000 gallons |
| 240 to 360 gal/day | 1,500 gallons |
| 360 to 600 gal/day | 2,000 gallons |
| 600 to 720 gal/day | 2,500 gallons |
| 720 to 840 gal/day | 2,750 gallons |
| 840 to 920 gal/day | 3,000 gallons |
| 920 to 1,040 gal/day | 3,250 gallons |
Septic setbacks in Hardin County
| From | To | Distance |
|---|---|---|
| LineString | Fence Line | 5 Ft |
| LineString | Gas Line | 10 Ft |
| LineString | Geothermal horizontal closed loop systems | 10 Ft |
| LineString | Grey water recycling system | 10 Ft |
| LineString | Intermittent stream | 10 Ft |
| LineString | Irrigation lines | 10 Ft |
| LineString | Perennial stream | 50 Ft |
| LineString | Property Line or Right-of-way | 10 Ft |
| LineString | River | 50 Ft |
| LineString | Road cut-banks or stream cut-banks | 50 Ft |
| LineString | Swales | 10 Ft |
| LineString | Utility Service Line | 10 Ft |
| LineString | Vertical open and closed loop geothermal heating and/or cooling system | 50 Ft |
| LineString | Water Supply Source | 50 Ft |
| Point | Sealed well | 10 Ft |
| Polygon | Buildings or other structures | 10 Ft |
| Polygon | Driveway or other Hardscape | 10 Ft |
| Polygon | Existing Septic Component to be Abandoned | 5 ft |
| Polygon | Lake | 50 Ft |
| Polygon | Recorded easements | 10 Ft |
| Polygon | Roadway or Surface | 10 Ft |
| Polygon | Surface water impoundment | 50 Ft |
| Polygon | Wetland | 50 Ft |
These are the values the landplan.io design engine applies in Hardin County. Confirm a design with the Ohio health department or your county's before you build.
Septic tank cost in Hardin County
There are too few listings in Hardin County for a county price. Across Ohio the median delivered aeration tank costs $7,235 (October 2026); most sell between $6,044 and $9,015. All septic product prices in Ohio
Parcel data in Hardin County
landplan.io has parcel boundaries for Hardin County (100% of its area): type an address and the design starts from the parcel.
Septic companies, designers and jobs in Ohio
Where the rules come from
The regulations and documents landplan.io's Hardin County, Ohio rules are read from:
- Chapter 3701-29 - Sewage Treatment Systems (Household/Small Flow On-Site Sewage Treatment Systems) (Ohio Admin. Code Chapter 3701-29)
- Rule 3701-29-15 General soil absorption standards (with Table 3 Soil Infiltration Loading Rates and Table 4 Hydraulic Linear Loading Rate Table) (Ohio Adm.Code 3701-29-15)
- Rule 3701-29-15 Appendix B - Sand mound (Ohio Adm.Code 3701-29-15, Appendix B)
- Rule 3745-9-04 Well siting (public water system well sanitary isolation radius) (Ohio Adm.Code 3745-9-04)
- Rule 3701-29-15 Appendix C - Drip distribution systems (Ohio Adm.Code 3701-29-15, Appendix C)
- Rule 3701-29-15 Appendix A - Technical standards for use of leaching trenches for soil absorption (Ohio Adm.Code 3701-29-15, Appendix A)
- Tanks Approved for use in Sewage Treatment Systems (Approval Chart of Septic Tanks) (ODH tank approval chart, updated 9/28/2026)
- Tangent - Tangent LandSaver MBR Plastic Tank up to 600 Gallon approval (ODH Pretreatment Components)
- Infiltrator Water Technologies - Presby AES Approval Chart (ODH Pretreatment Components)
- Premier Tech - Premier Tech Aqua Ecoflo Coco Filter Approval Chart (ODH Pretreatment Components)
- Infiltrator Water Technologies - Infiltrator ATL Approval Chart (ODH Pretreatment Components)
- IMET Corporation - IMET Corporation Approval Chart (ODH Pretreatment Components)
Near Hardin County
- Logan County
- Wyandot County
- Hancock County
- Allen County
- Marion County
- Union County
- Auglaize County
- Putnam County
- All of Ohio
Questions
What septic systems are allowed in Hardin County?
landplan.io designs by Ohio's state rules there and permits: Mounded Leaching System, Spray Distribution System, Low Pressure Pipe System, Drip Distribution System, Leaching Trench System, Infiltrator Advanced Treatment Leachfield (ATL), Infiltrator Advanced Enviro-Septic® (AES) and Discharging System.
What size septic tank do I need in Hardin County?
landplan.io sizes the septic tank in Hardin County from the daily design flow: up to 240 gal/day: 1,000 gallons; 240 to 360 gal/day: 1,500 gallons; 360 to 600 gal/day: 2,000 gallons; larger flows need larger tanks. A home's design flow is 120 gal/day per bedroom, at least 240 gal/day.
How far must a septic system be from a well in Hardin County?
landplan.io keeps these distances in Hardin County: Point to sealed well: 10 Ft.
How much does a septic tank cost in Hardin County?
Across Ohio the median delivered aeration tank cost $7,235 in October 2026, most between $6,044 and $9,015; there are too few listings for a Hardin County price. Installation is extra.
Does landplan.io have parcel data for Hardin County, Ohio?
Yes: parcel boundaries cover Hardin County (100% of its area).