Septic Systems

The purpose of a home's subsurface sewage disposal system (septic system) is to dispose of the waste water generated by the occupants in such a manner that the soils on the property can disperse it without causing an adverse effect on groundwater and in turn on public health and the environment. In our District 12,000 homes rely on on-site sewage disposal systems.

The Chatham Health District is responsible for:

  • Issuing permits for all activities related to the construction or repair of any subsurface sewage disposal system.
  • Investigating any complaints related to failing septic systems.
  • Reviewing and approve plans for septic systems.
  • Conduct soil testing evaluations and percolation tests to assure site suitability.
  • Retain records for all new and repaired septic systems including as-built drawings.
  • Assure that any construction activities, or change in use of the property, does 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 the Chatham Health District to obtain a permit if they are:

  • Altering or repairing any part of a subsurface sewage disposal system.
  • Construct a new system.
  • Plan to construct an addition, accessory structure (decks, etc.) or outbuildings.
  • Plan on increasing the number of bedrooms.
  • Plan to install a swimming pool.
  • Approval is needed from the District before a building permit can be obtained. If you have any questions or comments, please contact a District Sanitarian. You can view the subsurface sewage disposal technical standards on the State Department of Public Health’s website.

Ground Water Monitoring
The Chatham Health District may require groundwater monitoring on any site where there is reason to believe that maximum groundwater is less than 36” below grade. In general, if there is any question that groundwater is less than 18” from the ground surface for a month or more of the year, monitoring will be required to document suitability.

Soils Testing
Soil testing for new lots generally consists of at least four deep test holes, approximately seven feet deep. This allows for a good interpretive reading of the different soil layers to determine if any limiting factors, such as groundwater, ledge, excessive slope, or soil compaction exist. Percolation tests are smaller and shallower holes which help us to determine how quickly the soil accepts water. Along with the proposed use of the structure, soil testing gives us the ability to properly size and locate a septic system.

If public sewers are not available, new lots will require soil testing to assure that the soils are suitable for the proposed development. A proper site assessment is an important first step to avoid expensive installation of public sewers. All deep test holes are observed by a representative of the Chatham Health District to determine site limitations. When properly designed, septic systems provide a safe and efficient means of treating sewage.

For proposed building additions, if soil testing is not on file, soil testing is mandatory to determine site suitability. The intent of this requirement is to prevent expansion of buildings if the land is not capable of supporting the addition.

Any questions regarding soil testing, whether you wish to schedule testing or need help interpreting the results can be directed to any of the offices the Chatham Health District maintains.