On-Site Septic Systems

The purpose of the Onsite Septic System (OSS) program is to ensure proper treatment and disposal of wastewater to protect our drinking water and the environment. At Grant County Health District (GCHD) we permit, inspect, and investigate complaints associated with on-site septic systems. Other activities include site and design reviews and reviews of proposed land developments. The GCHD is responsible for overseeing the design and installation of on-site septic systems with wastewater flows under 3,500 gallons per day.

We also maintain records of existing on-site sewage systems. These can be requested through a public records request or through our online records portal. To help find your records, please add as much information as possible, including the address and parcel number. The year the OSS was installed, and the name of the owner on the original permit can also be helpful.

Please note: GCHD cannot accept new septic applications for properties under Grant County’s authority without first applying for a Grant County building permit. This process does not apply to most septic system repairs. A letter to septic professionals (PDF). Please note, that the site plan submitted with the building application must contain all septic system components, including tanks, lines, drainfield, and reserve area, as well as the well and water distribution line from the well to the building(s). This site map must match the site map submitted with the OSS application.

The current On-Site Septic (OSS) rules, went into effect on April 1, 2025. This statewide rule regulates the location, design, installation, operation, maintenance, and monitoring of OSS. All parts of the new rule, except property transfer inspections, is now in effect. For more information on changes to WAC 246-272A go to the Department of Health's website:

The new GCHD ordinance is also in effect.

Some of the key changes to GCHD's ordinance include:

  • Septic maintenance service providers must be certified through GCHD before they can do inspections for OSS.
    • Beginning January 1, 2026, septic maintenance service providers show proof of passing the Washington On-Site Sewage Association (WOSSA) O&M Level 2 (Specialist) exam before they can be certified.
  • Updated OSS setbacks to align with the state rule.
  • Installation start permits for designs approved under the new rule, will expire in 2 years instead of 1.
  • Previous design approval will expire on March 31, 2026.
  • All polyethylene, fiberglass, or other approved tanks that are assembled from 2 halves, used must be filled with water at the time of inspection to verify water tightness or provide certification of water tightness from tank manufacturer or other approved 3rd party.



Publicly available documents can be searched from our online portal. The site is for informational purposes only. The information available is provided on an “as is”, “as available” and “with all faults” basis. The information can change over time without notice.

Records, drawings, and other documents have been gathered over many decades, using differing standards for quality control, documentation and verification. While the data is generally believed to be accurate, neither Grant County Health District nor it’s officials or employees make any warranty of any kind for this information, express or implied. Information on the site is not intended to constitute advice nor is it to be used as a substitute for advice from a licensed professional. You should not act or refrain from acting based on the information on this site without independently verifying the accuracy of the information and as necessary, obtaining professional advice concerning your own situation and any specific questions you may have.

Click here for the On-Site Septic Records Public Portal.