Septic permit rules and requirements in Connecticut
In Connecticut, the state sets the rule. The septic permit comes from your local director of health. The smallest tank allowed is 1,000 gallons. Regulations of Connecticut State Agencies §§ 19-13-B100a and 19-13-B103 · checked 2026-09-12
Environmental Engineering Program
Writes the rules
checked 2026-09-23
Your local director of health
Issues the permit
checked 2026-09-12
Who permits a septic system in Connecticut
Your local director of health issues the permit. The state sets the floor through the Environmental Engineering Program, Connecticut Department of Public Health.
Local officials issue permits for most home septic systems. The state permits larger or unusual systems instead.
Regulations of Connecticut State Agencies §§ 19-13-B100a and 19-13-B103 · checked 2026-09-12
The office publishes its own page on this: Connecticut Department of Public Health — Environmental Engineering Program.
The office's own page names this same address as its canonical link.
Connecticut Department of Public Health — Environmental Engineering Program · checked 2026-09-23
Why Connecticut has no county page
No county in Connecticut issues the septic permit. A town or a group of towns issues it instead.
The Census Bureau marks all 8 Connecticut counties as governments that do not function. This confirms no county here issues a septic permit.
U.S. Census Bureau — 2020 national county file · checked 2026-09-12
What state law requires
Does Connecticut require a percolation test?
Connecticut requires a percolation test before it approves a leaching system design.
Regulations of Connecticut State Agencies §§ 19-13-B100a and 19-13-B103, effective September 1, 2026 · checked 2026-09-23
The minimum septic tank size Connecticut allows.
1,000 gallons.
Applies to a house with 1 to 3 bedrooms.
Regulations of Connecticut State Agencies §§ 19-13-B100a and 19-13-B103, effective September 1, 2026 · checked 2026-09-23
How far a system must sit from a well in Connecticut.
75 feet.
Applies to a private well drawing less than 10 gallons a minute.
Item A covers a well.
Regulations of Connecticut State Agencies §§ 19-13-B100a and 19-13-B103, effective September 1, 2026 · checked 2026-09-23
Must the installer be licensed in Connecticut?
Connecticut licenses installers before they may build a septic system.
Chapter 393a of the General Statutes sets this rule. The department licenses installers.
Connecticut General Statutes, Chapter 393a — Subsurface Sewage Disposal System Installers and Cleaners · checked 2026-09-23
Sources
State records only. Each figure above has a government source and a checked-on date. County figures live on the county pages.
- Connecticut Department of Public Health — Environmental Engineering Program
- U.S. Census Bureau — 2020 national county file
- Regulations of Connecticut State Agencies §§ 19-13-B100a and 19-13-B103, effective September 1, 2026
- Connecticut General Statutes, Chapter 393a — Subsurface Sewage Disposal System Installers and Cleaners
Verify before you act. Septic rules are set locally and they change. Check anything here with your local director of health before you spend money on it.