State and Local On-Site Sewage Regulations

What are the Washington State requirements for On-Site Sewage Systems (OSS)?
How do they affect San Juan County homeowners?

Two important laws regulate the way OSS are managed in Washington.
As of July 01, 2007, state regulations (WAC 246-272A) require that homeowners properly maintain their on-site sewage systems. At a minimum, this law requires all owners of traditional gravity systems to have their systems properly inspected at least once every 3 years. It requires owners of alternative systems (those with pumps) to be inspected every year. San Juan County, like all counties state-wide, must maintain records of the inspections within its jurisdiction.

Another state law (RCW 70.118A) requires all 12 Puget Sound local health jurisdictions, including San Juan County, to identify and develop Marine Recovery Areas (MRA) for areas where OSS contribute to certain environmental problems — such as threatened or downgraded shellfish growing areas, marine water with low dissolved oxygen or fecal coliform, and marine waters where nitrogen has been identified as a contaminant of concern. For systems within an MRA, there may be more stringent requirements for homeowners.

Why did the State adopt these laws?
OSS are a very effective technology to manage human waste if they are properly maintained. However, systems that are not maintained can fail. In Washington State, failing systems have caused public health problems, and pollution of surface waters like rivers, lakes, and near-shore shellfish growing areas — as well as the groundwater we drink. Having your system inspected on a regular basis can prevent failures, preserve and enhance water quality, and keep our water sources safe from contamination. A well-maintained system can also save you money in the long-term by preventing costly repairs.

What are the homeowner’s responsibilities?
The State code requires OSS owners to obtain a complete evaluation of their system components and/or property to determine functionality, maintenance needs, and compliance with regulations and permits. Inspections must be conducted according to the following schedule:

    (a) Gravity systems need to be inspected every three years unless located in a designated sensitive area (see MRA regulations, above).
    (b) All other systems — including but not limited to pressure systems, sand filters, mound systems, gravity systems located in designated sensitive areas, and aerobic treatment systems — are required to be inspected on an annual basis.

Are homeowners allowed to inspect their own systems?
Homeowners are allowed to perform their own OSS inspections if all of the following criteria can be met:

  1. San Juan County has an existing record of the system (permit, sanitary survey, as-built record drawing).
  2. The OSS owner has successfully completed a county-approved OSS inspection training and certification program.
  3. The system is not within an MRA (see above).
  4. The system is not a proprietary system (Advantex, Multi-Flo, Nayadic, et al), as these require additional certification from the manufacturers.

If any of these criteria are not met, then your system must be inspected by a professional septic inspector.

How do I get trained to inspect my own OSS?
San Juan County Health & Community Services offers monthly classes from spring through fall on Lopez, Orcas and San Juan Islands. For more information and a schedule of classes, visit

Homeowners who successfully complete the Homeowner Training Inspection Class are certified to inspect only their own systems. You will not be able to inspect your neighbors’ systems or a system where you are the tenant of the property but are not the property’s owner.

Is there any way I can look up my own system’s inspection history?
Yes! The San Juan County Health department’s septic permit database is now online at San Juan County Environmental Health. You can search by your property’s parcel number or address, or by your system’s design or permit number. (Note that the record will show the name of the property owner at the time the permit was issued.)

If you cannot find your system online, and would like to get information about it, please contact San Juan County Health & Community Services.