Septic Systems

Within Ledge Light Health District, many homes rely on on-site sewage disposal systems to treat their waste water. These systems are typically comprised of a septic tank used in conjunction with a distribution system and leaching structure (s). The waste flows from the house to the septic tank, where the separation of solids and fats/oils/greases occurs. The solids accumulate in the bottom of the septic tank (and should be periodically pumped out) and the liquid is dispersed over a large area of soil through the leaching structures (galleries, drywells, trenches or proprietary products), where biological filtration takes place. Information about septic systems is available at the State of Connecticut Department of Public Health. Ledge Light Health District is responsible for:

  • Permitting all activities related to the construction or repair of any subsurface sewage disposal system.
  • Investigating any complaints related to failing septic systems.
  • Reviewing and approving plans for septic systems.
  • Conducting soil evaluations and percolation tests to assure site suitability.
  • Retaining records for all new and repaired septic systems including as-built drawings.
  • Assuring that any construction activities, or change in use of the property, do not adversely impact the on-site septic system or reduce potential repair area.

Homeowners, or their representatives (contractors), who rely on subsurface sewage disposal are required to contact Ledge Light Health District to obtain a permit if they are:

  • Altering or repairing any part of a subsurface sewage disposal system.
  • Constructing a new system served or to be served by an onsite septic system.
  • Planning to construct an addition, accessory structure (decks, etc.) or out-buildings.
  • Planning on increasing the number of bedrooms.
  • Planning to install a swimming pool.
  • Doing a lot line revision.

Click here for information about septic safety during a natural disaster.

If you have any questions or comments, please contact an LLHD Sanitarian. You can view the subsurface sewage disposal technical standards on the State Department of Public Health’s website.


Helpful Resources

For any questions regarding public sewers, please contact:

  • East Lyme Water and Sewer Department: 860-739-6931, ext. 150
  • City of Groton Engineering Department: 860-446-4166
  • Town of Groton Engineering Department: 860-448-4066
  • Ledyard Water Pollution Control Authority: 860-536-3181
  • New London Public Utilities: 860-447-5221
  • Stonington Water Pollution Control Authority: 860-535-5065
  • Waterford Utility Commission: 860-444-5886
  • CT State Subsurface Sewage Disposal Systems Exam Preparation

Applicable Statutes/Regulations

Guidance Documents

Fees