State guide
Connecticut
Connecticut regulates household septic systems through the Department of Public Health's subsurface sewage rules and technical standards, but permits for systems on sites with design flows of 10,000 gallons per day or less are issued by the local Director of Health. The statewide DPH page also publishes the current local-health permit and site-investigation forms and notes revisions effective September 1, 2026.
Checked against official sources on October 4, 2026. Rules and links change; confirm with the office listed before you act.
- Who regulates septic permits
- Connecticut DPH sets the statewide subsurface sewage rules, but local health departments or districts regulate and permit most onsite systems, with DEEP involved for higher-flow or alternative systems.
- Who can do the soil or perc test
- Official Connecticut materials say the site investigation is made by the local director of health or a Connecticut-registered professional engineer representing the applicant, and the local director of health assures the accuracy of the soil tests and pits.
- Official septic permit page
- Official page →
- State fee
- Not published by an official source we could verify. Ask the office.
Official resources in Connecticut
State DPH overview page for septic regulations, technical standards, exception forms, and local-health Forms 1-4.
Use this state map and table to identify the local health department or district that actually handles your septic permit.
DPH licensing page for Registered Sanitarians and septic installers, with links to Connecticut license verification.
Key facts for Connecticut
- Systems on sites with design flows of 10,000 gpd or less are permitted by the Local Director of Health.
- Plans for septic systems serving buildings with design flows between 2,000 and 10,000 gpd must be approved by Connecticut DPH.
- Site investigations are made by the local director of health or a Connecticut-registered professional engineer representing the applicant.
- The local director of health must assure the accuracy of soil tests and deep observation pits.
- Connecticut has 59 local health agencies, so residents usually work with a town or district office rather than a county office.
- DPH posts Form 1 permit applications and Form 2 site-investigation forms for local health use on its statewide septic page.
County septic and soil-evaluation offices in Connecticut
| County office | city | phone | Details |
|---|---|---|---|
| North Central District Health Department — Windham Office Windham County | Willimantic | Not published* | This office's application form is for site investigation and seepage testing for septic repairs, replacements, additions, conversions, or use changes. |
| North Central District Health Department — Stafford Office Tolland County | Stafford Springs | Not published* | The same district form lists this office for septic site-investigation and seepage-test applications in the district's rural towns. |
| Eastern Highlands Health District Main Office Tolland County | Mansfield | (860) 429-3325 | EHHD says it oversees septic installations and repairs from site investigation and soil testing through plan review, permit approval, and construction inspection. |
| Chatham Health District Main Office – East Hampton Middlesex County | East Hampton | Not published* | Chatham says district staff handle septic inspection and approval, and its environmental-health page links online septic permits and related services. |
| Chatham Health District — Colchester Office New London County | Colchester | (860) 537-7214 | This office is listed on Chatham's contact page for one of the district's more rural service areas. |
* Not published: the official page doesn't list it. Call the office to confirm before you rely on it.
What to do next
- Start by finding your local health department or district; that office usually schedules soil testing, reviews plans, and issues the permit to discharge.
- Ask the local sanitarian whether your project is only a B100a review for an addition or a full septic site investigation and permit application.
- If a professional engineer is involved, confirm early who will dig pits, provide water, and attend the site investigation.
Not seeing your county office or county?
Not every county office publishes its rules online. Try these, in order:
- General Start with the statewide information above.
- Closest verified Nearest places where we have verified local data outside this state (distance from Connecticut's population center, for comparison only):
- Suffolk County Department of Health Services - Residential Permits, New York · about 40 miles
- Board of Health, Massachusetts · about 63 miles
- Ulster County Department of Health - Sewage Disposal Systems, New York · about 66 miles
- Call to confirm Ask the official office.Environmental Practitioner Licensure
Website →Phone: (860) 509-7559 (as listed on that page, checked Oct 4, 2026)Your city or county office: Local governments →Not sure who handles it locally? USAGov's free help line, 1-844-872-4681, or the Connecticut page on USA.gov can point you to the right office. - Know the current info? Tell us with a link to the official page.