Concrete septic tank buried in dirt and partially exposed.

Subsurface Sewage in Connecticut

Septic systems, defined as subsurface sewage disposal systems, are regulated by Sections 19-13-B100a and 19-13-B103 of the Regulations of Connecticut State Agencies and the associated Technical Standards for Subsurface Sewage Disposal Systems (Technical Standards).

  • Septic systems on sites with design flows of 10,000 gallons per day (gpd) and less are permitted by the Local Director of Health.
  • Plans for large septic systems serving buildings with design flows between 2,000 and 10,000 gpd must be approved by the Connecticut Department of Public Health.
  • Septic systems on sites with design flows exceeding 10,000 gpd and alternative treatment systems are permitted by the CT Department of Energy and Environmental Protection.

Septic System Resources for Homeowners

Use the links below to find out more about your septic system and how to care for it, as well as financial assistance options for system repairs.

Financial Assistance for Septic System Repairs

Informational Resources

Exception Application Forms

EHDW Circular Letter 2024-29 with guidance on submitting exception applications to EEP. 

All exception applications are for local health use only.

We encourage electronic completion and submission utilizing the Electronic Form (e-form) and attaching relevant scanned copies of supporting documentation.

EHDW Circular Letter 2024-29 with guidance on submitting exception applications to EEP. 

SSDS Training Opportunities

Each fall, DPH offers Phase I and Phase II courses that are open to sanitarians, local health officials, and other municipal officials currently employed by a local health department and/or a municipality. Preregistration for the training is required, and space is limited. Sessions run by DPH typically run each fall and registration is announced during the summer.

Each spring semester, Phase I is offered as part of the Environmental Health Training Program (EHTP), which is an environmental health workforce development program co-sponsored by the Southern Connecticut State University (SCSU) Public Health Program and the Connecticut Department of Public Health. The program consists of three modules: Food Protection, Subsurface Sewage Disposal, and General Environmental Health Topics.

TrainCT Webpage for Phase I (Fall Sessions – Local Health) 

Visit the TrainCT course webpage for the annual Phase I training for local health officials.

TrainCT Webpage for Phase II (Fall Sessions - Local Health) 

Visit the TrainCT course webpage for the annual Phase II training for local health officials.

SCSU Environmental Health Training Program webpage 

Learn more about Southern Connecticut State University's Environmental Health Training Program.
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Correspondence and Historical Circular Letters
Read previously issued circular letters and other correspondence related to septic systems, water treatment wastewater, exception applications, and more using the link below.

Click here to become SepticSmart!
Common household leaks can add hundreds of extra gallons of water every day, stressing your septic system. Overloading your septic system with water is a leading cause of failure. For the long-term care of your system, have your septic tank inspected and pumped out by a CT licensed septic tank cleaner or installer as needed (on average every 3-5 years). For more information on septic systems and how to care for yours, visit the SepticSmart webpage linked above.
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Subsurface Sewage Disposal System Installers and Cleaners

Read more about licensing and examination requirements for subsurface sewage disposal system installers and cleaners using the resources linked below.
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DPH Code Advisory Committee