Septic system requirements in Johnson County, Iowa
The septic rules landplan.io applies in Johnson County, what a septic tank costs there, and the parcel data we hold.
Updated
Design a septic system for an address in Johnson County
Iowa's state rules apply in Johnson County: landplan.io has no county rules of its own here. State rules: Reviewed See Iowa's rules
Septic systems allowed in Johnson County
The system types landplan.io permits in Johnson 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 Johnson County
The daily design flow of a home: 150 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 Johnson County
| From | To | Distance |
|---|---|---|
| Polygon | Existing Septic Component to be Abandoned | 5 ft |
These are the values the landplan.io design engine applies in Johnson County. Confirm a design with the Iowa health department or your county's before you build.
Parcel data in Johnson County
landplan.io has parcel boundaries for Johnson County (100% of its area): type an address and the design starts from the parcel.
Septic companies, designers and jobs in Iowa
Where the rules come from
The regulations and documents landplan.io's Johnson County, Iowa rules are read from:
- Private Sewage Disposal Systems (Iowa Admin. Code r. 567 Chapter 69)
- Iowa DNR Onsite News - Chapter 69 Legislative Session Delay (guidance on which separation distances apply) (Iowa DNR Onsite News bulletin (GovDelivery IACIO 3f26912))
- Story County Ordinance No. 287 - Chapter 65, Private Sewage Disposal Systems (signed ordinance) (Story County, Iowa, Code of Ordinances ch. 65 (Ordinance No. 287))
- Iowa DNR copy of 567 IAC 60.2(2)"c" Table I - Wastewater Separation Distances (from ch. 60, effective 6/18/2025) (Iowa Admin. Code r. 567-60.2(2)"c", Table I (DNR copy))
- Chapter 60 - Scope of Title, Definitions, Forms, Rules of Practice (Table I: Wastewater Separation Distances, 567-60.2(2)"c") (Iowa Admin. Code r. 567-60)
Near Johnson County
- Washington County
- Cedar County
- Iowa County
- Muscatine County
- Linn County
- Louisa County
- Benton County
- Keokuk County
- All of Iowa
Questions
What septic systems are allowed in Johnson County?
landplan.io designs by Iowa'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 Johnson County?
landplan.io sizes the septic tank in Johnson 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 150 gal/day per bedroom, at least 240 gal/day.
Does landplan.io have parcel data for Johnson County, Iowa?
Yes: parcel boundaries cover Johnson County (100% of its area).