How to get a septic system permit
All four states require a permit before a new septic system goes in or a failing one is replaced, with narrow exceptions such as Missouri's large-lot exemption, and a soil evaluation usually comes first.
Arkansas: permits and soil testing
An ADH Permit for Construction is required before a system is built, altered, repaired or extended, and the system may not be used until ADH or its Authorized Agent inspects it and issues a Permit for Operation. Part I of the application must be completed by a Designated Representative, and plan review fees run from $30 to $150 by house size ($30 for a repair). Homeowners keep the right to install and repair their own system under the rules, and a single residence on 10 or more acres with every part of the system more than 200 feet from any property line is exempt.
ADH relies on soil pits rather than percolation tests to judge a site, and the soil work and system design must be done by a Designated Representative (DR): a registered engineer, land surveyor or sanitarian, or a licensed master plumber, certified by ADH. Only a Soil Qualified DR may size a system from seasonal water table data. ADH publishes no fixed price for this work; state law lets DRs charge reasonable fees based on prevailing wage rates.
- Plan review fee by heated structure size: 1,500 sq ft or less $30; 1,501 to 2,000 $45; 2,001 to 3,000 $90; 3,001 to 4,000 $120; over 4,000 $150; alteration, repair or extension $30 (Rule 4.9.1).
- Construction must begin within one year of permit issuance or the permit must be re-validated (Rule 4.9).
- Installers must notify the Authorized Agent at least 24 hours before starting work; emergency repairs may start first if a permit is obtained within 10 working days (Rule 4.7).
- A permit is refused where public sewer is reasonably available (Rule 4.10.4); premises within 300 feet of an available sewer must connect (Rule 4.1).
- Apply through the county health unit's Onsite Environmental Specialist, or online at https://septictankpermitonline.adh.arkansas.gov/.
- Monitoring of seasonal water tables is done by a Professional Soil Classifier or DR (Rule 7.4.3.7).
- DR registration costs $100 a year and requires an ADH exam and annual training (Rule 13.1).
- Find DRs by selecting the 'Designated Representative' licence type in the ADH licensee search.
Sources: Arkansas State Board of Health, Rules Pertaining to Onsite Wastewater Systems (effective Sept 5, 2024), Section 4.10.3; Act 402 of 1977 as amended, Ark. Code Ann. 14-236-101 et seq. (ADH copy), 14-236-102(b)(2); ADH Onsite Wastewater FAQs
Oklahoma: permits and soil testing
Before installing a new system or modifying an existing one, the installer must obtain a DEQ Authorization to Construct (ATC), or an individual permit for an alternative design, and DEQ must review the Report for On-Site Sewage (Form 581) first. Every new installation, modification or repair must be inspected by DEQ, or self-inspected by a DEQ-certified installer, before backfill. Since November 1, 2025, a person who is not DEQ-certified may install only one system per calendar year, and DEQ must inspect it with that installer present.
A soil test is required to site and size the dispersal field for new systems and modifications, except lagoons and some spray-irrigation aerobic systems sized for Group 5 soil. Soil profile tests may be done only by DEQ or DEQ-certified soil profilers, who must also be an Oklahoma-registered engineer, land surveyor, professional sanitarian or environmental specialist, or a soil scientist; percolation tests may be used only for conventional subsurface fields. DEQ's own soil profile fee is $250 when DEQ augers the holes and $150 when the applicant digs pits (2012 base, CPI adjusted).
- Base fees in 252:641-23-1 (effective July 1, 2012, adjusted each July 1 by CPI): new system up to 1,500 gpd $250 with a self-inspecting certified installer or $350 otherwise; over 1,500 gpd $450; modification $150 or $250; alternative system plan review $200.
- DEQ raised these fees again by CPI on July 1, 2026; the current dollar amounts were not shown on the pages we read.
- DEQ may waive fees for indigents and nonprofit organizations (252:641-23-1(b)).
- Buy ATCs and soil tests online; every request needs the Section, Township and Range from the deed or county assessor.
- Certified installers must submit final inspections to DEQ within 15 days of completion.
- Percolation tests may not be performed in scenic river corridors or water body protection areas (DEQ web page).
- Soil profilers are certified yearly (Feb 1 to Jan 31); annual certification fee $200 and exam fee $150 (252:641-23-3).
- Soil profiler list: https://oklahoma.gov/deq/divisions/ecls/on-site-sewage-programs/deq-certified-soil-profilers/soil-profiler-list.html
- DEQ performs a soil profile at no charge when investigating a malfunctioning system or a third-party complaint (252:641-23-1(b)(2)).
Sources: OAC 252:641, Individual and Small Public On-Site Sewage Treatment Systems (amended through 9-15-24), 252:641-1-2.1(a); Oklahoma DEQ, On-Site Sewage Treatment; Oklahoma DEQ, FAQs for Changes Effective November 1, 2025; Oklahoma DEQ, ECLS Online Payments
Missouri: permits and soil testing
A construction permit is required before installing a system or making a major modification or major repair, except on single-family residential lots of three acres or more (and certain lots of ten acres or more) where every part of the system is more than 10 feet from any adjoining property line and no effluent reaches a neighbor's property or pollutes water; some counties do not honor that exemption. Effective August 28, 2026, Senate Bill 914 removed the $90 state permit fee from RSMo 701.046 and DHSS has temporarily suspended its application fees until new fees are set; counties with their own ordinance set their own fees. Property owners may install, modify or repair their own system if they follow the law, and need no permit to clean it.
Percolation tests and soil morphology evaluations used to design a system must be done by individuals registered with DHSS. Perc testers qualify through a DHSS course or as an engineer, geologist or soil evaluator; soil morphology evaluators must be soil scientists (15 credit hours of soils, 3 in morphology) or engineers or geologists with 10 soils hours, and pass a written and field exam at 70 percent. DHSS charges registrants a $90 processing fee but publishes no price for the test itself; a 2026 law change says a perc test may be accepted at local discretion only if a soil morphology evaluation cannot reasonably be obtained.
- Plans and specifications must be approved before a permit to install or make a major repair (19 CSR 20-3.060(1)(C)3).
- Examples of major changes that need a permit: replacing a sewage tank, or replacing or expanding an absorption field (DHSS).
- The 3-acre exclusion does not apply to lots next to lakes run by the Corps of Engineers or a public utility (RSMo 701.031).
- Generally no permit is needed to abandon a sewage tank, but check the county first (DHSS FAQ).
- Registrations last 36 months and require continuing education (19 CSR 20-3.080(7)).
- RSMo 701.040(5), effective Aug 28, 2026, requires a mandatory registration program with continuing education for perc testers before January 1, 2027; that subdivision is void after December 31, 2026.
- Find registered soil evaluators and perc testers on the DHSS Find a Professional map: https://experience.arcgis.com/experience/5c6151e541b74668bbaad632725224fe
- Counties with ordinances may require a soil morphology report for every permit.
Sources: Missouri DHSS, OWTS Construction Permit Process; Missouri DHSS, Onsite Wastewater Frequently Asked Questions; RSMo 701.055, 701.055(1); RSMo 701.046 (effective Aug 28, 2026), 701.046; 19 CSR 20-3, Missouri Code of State Regulations, DHSS General Sanitation (9/30/20 compilation), 19 CSR 20-3.080(3); RSMo 701.040 (effective Aug 28, 2026), 701.040(5)
Tennessee: permits and soil testing
Property owners and installers need a TDEC construction permit before building, altering, extending or repairing a system, and a modification permit when adding bedrooms or building over part of an existing system. A new conventional system costs $400 up to 1,000 gallons per day plus a $100 construction inspection; alternative systems are $500 plus a $200 inspection; repairs carry no permit fee but a $100 inspection, and TDEC designs the repair. Owners may install a system on their own residential property without an installer permit, but still need the construction permit.
Site suitability for a conventional system is set by a high or extra-high intensity soil map made by a TDEC-approved soil consultant, and an extra-high intensity map must be submitted before TDEC will evaluate a lot for an alternative system. Where percolation tests are used, they must be run by a Tennessee-licensed engineer or surveyor, or by an approved soil consultant or registered professional environmentalist not employed by a government agency. Soil consultants are private and TDEC does not publish their fees.
- Additional flow: $100 per extra 1,000 gpd (conventional) or $150 (alternative); experimental systems $500.
- Review generally takes 10 days and must be finished within 45 days of a complete application; the permit expires three years after issue.
- Before the site visit, stake the property lines and house corners and mow the site.
- Electrical service to a new home requires proof of a septic permit application, sewer service or an existing system (T.C.A. 68-221-414).
- Approved soil consultants need a soils-related degree, two years of soil evaluation experience and 80 percent scores on written and field mapping tests (0400-48-01-.18).
- Soil consultant list: https://www.tn.gov/content/dam/tn/environment/water/land-based-systems-unit/wr-sds-soil-consultants.pdf
- A TDEC-certified soil scientist may submit a complete permit application for systems under 750 gallons per day (T.C.A. 68-221-403(m)(12)).
Sources: Tenn. Comp. R. & Regs. 0400-48-01, Regulations to Govern Subsurface Sewage Disposal Systems (April 2014 revised), 0400-48-01-.06(1); TDEC, Online Application for Septic Related Services; TDEC, SSDS Construction Permit
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Find a licensed installerCommon questions
Do I need a permit to install a septic system in Arkansas?
An ADH Permit for Construction is required before a system is built, altered, repaired or extended, and the system may not be used until ADH or its Authorized Agent inspects it and issues a Permit for Operation. Part I of the application must be completed by a Designated Representative, and plan review fees run from $30 to $150 by house size ($30 for a repair). Homeowners keep the right to install and repair their own system under the rules, and a single residence on 10 or more acres with every part of the system more than 200 feet from any property line is exempt.
Do I need a permit to install a septic system in Oklahoma?
Before installing a new system or modifying an existing one, the installer must obtain a DEQ Authorization to Construct (ATC), or an individual permit for an alternative design, and DEQ must review the Report for On-Site Sewage (Form 581) first. Every new installation, modification or repair must be inspected by DEQ, or self-inspected by a DEQ-certified installer, before backfill. Since November 1, 2025, a person who is not DEQ-certified may install only one system per calendar year, and DEQ must inspect it with that installer present.
Do I need a permit to install a septic system in Missouri?
A construction permit is required before installing a system or making a major modification or major repair, except on single-family residential lots of three acres or more (and certain lots of ten acres or more) where every part of the system is more than 10 feet from any adjoining property line and no effluent reaches a neighbor's property or pollutes water; some counties do not honor that exemption. Effective August 28, 2026, Senate Bill 914 removed the $90 state permit fee from RSMo 701.046 and DHSS has temporarily suspended its application fees until new fees are set; counties with their own ordinance set their own fees. Property owners may install, modify or repair their own system if they follow the law, and need no permit to clean it.
Do I need a permit to install a septic system in Tennessee?
Property owners and installers need a TDEC construction permit before building, altering, extending or repairing a system, and a modification permit when adding bedrooms or building over part of an existing system. A new conventional system costs $400 up to 1,000 gallons per day plus a $100 construction inspection; alternative systems are $500 plus a $200 inspection; repairs carry no permit fee but a $100 inspection, and TDEC designs the repair. Owners may install a system on their own residential property without an installer permit, but still need the construction permit.