Onsite Wastewater Treatment Systems (OWTS)

An Onsite Wastewater Treatment System (OWTS), commonly called septic or sewage systems, serves approximately 15,000 homes that are located outside of areas served by municipal sewer systems in Tompkins County.

An OWTS construction permit from Tompkins County Environmental Health is required before constructing a new OWTS or prior to conducting most repairs or replacing an existing system. Environmental Health OWTS staff will design most OWTS as part of the permitting process.

A construction permit must also be obtained before installing or replacing a septic tank, pump chamber or holding tank.

Permits & Payments

Fee Schedule(PDF, 83KB)

Use our online service for:

  • OWTS Permits and Certificates of Completion
  • Permit applications and payments for New Construction or Replacement OWTS

Click for Online Service

Construction Specifications & Requirements

Construction specifications for contractors and installers to reference and are to be used with an OWTS Construction Permit are available on the Onsite Wastewater Treatment System (OWTS) Details and Specifications page. Refer to your OWTS Construction Permit for the specific Details and Specifications required for your system.

Lot Size & Dimension Requirements

The following is not a complete representation of the Tompkins County Sanitary Code or of any specific Code sections cited. What is listed here is condensed and highlighted information from Article VI of the Tompkins County Sanitary Code for unofficial reference purposes only. Minimum lot size/dimension applies to new construction on undeveloped lots (including the siting of a mobile home) or conversions on lots where public wastewater treatment is not available.

Lot Size

  1. Lots must have enough usable area to furnish adequate separation distances between such features as wells and OWTS's and to allow enough room for a replacement OWTS.
  2. Minimum lot size for an OWTS construction permit is one acre of usable area Minimum lot size must be met by a single piece. See lot dimensions below.
  3. The building or OWTS must be located within the usable area.
  4. Construction permits for lots of 30,000 square feet or more created prior to August 17, 1977 will be considered if all other Code requirements can be met.
  5. Minimum lot size may be halved if the property is served by public water supply operated by a municipality or an approved water company.
  6. Usable area is land available for siting a building, its water and OWTS; useable area excludes such areas as Department of Environmental Conservation wet lands, swamps, bogs, flood plains, highways, rights-of-way, and other features.
  7. Minimum lot size required by towns and villages within Tompkins County can vary and will not necessarily be the same as the requirements of the Tompkins County Sanitary Code. Applicants for building or construction permits are advised to investigate all code requirements that may apply to their particular project.

Lot Dimensions

  1. Lots must be shaped such that, as a minimum, a circle of 150 feet diameter can be inscribed entirely within the confines of the usable area. This does not apply to lots of 30,000 square feet or more created prior to August 17, 1977.
  2. For lots with public water and those that can be halved, a circle of 100 feet in diameter is required.
  3. The Permit Issuing Official may consider waiving minimum lot size and lot dimension if a design professional is responsible for the OWTS design, submits a detailed developmental plan acceptable to the Department, and all other parts of Article VI can be met.

Grant-funded Programs

Tompkins County Environmental Health recognizes that a failing OWTS presents not only urgent public health hazards for residents but also a significant financial burden in many cases.

NYS grant funding for eligible Tompkins County property owners can assist with OWTS replacement costs:

Additionally, financial assistance may be available through the following programs (link to external websites):

  • Ithaca Neighborhood Housing Services (INHS)
    • Funding Available to Make Residential Units Accessible - INHS has been awarded funding to make residential units accessible for low- and moderate-income persons with disabilities in Tompkins County through the New York State Access to Home program. Allowable modifications include, but are not limited to wheelchair ramps and lifts, handrails, expanded doorways, and stair glides; roll in showers with grab bars, bathtub grab bars and seats; non-skid flooring; re-locating a bathroom or bedroom to the first floor.

    • Emergency Repair Assistance for Seniors - INHS has funds available from the NYS Restore Program to help homeowners in Tompkins County aged 60 or older make emergency repairs. The program helps low-income homeowners who live in single-family and manufactured owner-occupied homes with repairs that pose a threat to life, health, or safety of the homeowner. Potential emergency repairs include resolving hazardous conditions including, but not limited to, foundations, basements with standing water, fail septic and wells, stabilize, repair or replace damaged or leaking roof, accessibility modifications, failed HVAC systems, plumbing or electrical issues, and more.

    • Email rehab@ithacanhs.org or call (607) 277-4500 ext. 511 if you have questions about either of these INHS programs.
  • US Department of Agriculture (USDA)
  • Bishop Sheen Housing Foundation, NYS Homes & Community Renewal (HCR)

General Information

Downloads & Forms

Call the Environmental Health Division for additional information: (607) 274-6688.

3/5/2026

OWTS Topics

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