Monitoring / Inspection (EES)

"Monitoring and inspection" is also known as "evaluation of existing septic system (EES)."

Summary of Septic System Inspection Requirements


If you own a septic system anywhere in Washington State, you are required by state and local code to check your septic system on a regular basis to make sure it is working properly. How often you need to check your septic system depends on the type of system you have:
  • Basic septic systems with a tank and a gravity-fed drain field must be inspected at least once every three years. These systems are called conventional gravity septic systems.
  • Other types of septic systems must be inspected at least once a year. Pump to gravity, pressurized septic systems, sand filters, mounds, aerobic treatment units and other proprietary devices are in this category. These types of systems have pumps and other mechanical or electrical parts, and they need to be inspected more often than gravity systems.
  • All food service establishments such as restaurants must have annual septic system inspections.
Inspecting and maintaining your septic system is the responsibility of the property owner. You can hire a professional Operations and Monitoring Specialist or Licensed Septic System Designer to inspect your system for you. In many cases you can do it yourself with proper training and if you meet local requirements.

All on-site sewage systems require an inspection by a certified professional at some frequency and for some actions. View a table showing the required frequency of inspection by a professional (PDF). Examples of actions that require inspection by a professional are: At the time of sale or transfer of title, at the time of application for a building permit or other land use such as subdivision, boundary line adjustment or conditional use.

Non-Professional Inspection Criteria


If you own a septic system in Jefferson County, you can inspect your own septic system if all of the following criteria can be met:
  • The septic system is a residential system serving a single family residence or duplex on property you own.
  • You successfully complete a County-approved septic system training and certification program. Training includes Septic 101 and 201. Septic 101 covers the basics of septic system operation and maintenance. Septic 201 covers a step by step inspection of the septic system and reporting the results. It includes conventional gravity septic systems, pressure distribution systems, sand filter systems, and mound systems. Other system types such as aerobic treatment units, biofilters, drip irrigation and all systems with proprietary devices are ineligible for homeowner inspections and must be evaluated by a professional at the frequency required in state code.
  • Submission of the $10 homeowner authorization fee.
  • Your system is a conventional gravity septic system, pump to conventional gravity, pressure distribution system, sand filter system, or mound system.
  • There is an adequate record of the systems location on file at Jefferson County Environmental Health.
    • If the County has no record of a septic system on your parcel you will need to work with a certified operations and monitoring specialist or licensed designer to create a system location site plan for the property. The site plan must show the septic system components such as the septic tank and general drain field area along with the well (if applicable), house, garage, sheds and other outbuildings, driveways and the adjacent roadway. Click to view a sample site plan and a blank site plan.
    • If the records we have are inadequate we will ask you to contact the Environmental Health office, and together we will try to determine if there is enough documented information about your system. If there is not enough information to determine your system type and where its components are located you will be required to submit a system location site plan developed by a certified/licensed professional before your system will be eligible for you to inspect it.
    • After submittal of the system location site plan, you may qualify to inspect your own septic system if you meet the other criteria.
  • You will need to submit a report of your inspection activities to the County within 30 days of the septic system inspection, pay the report submittal fee and also ensure that needed maintenance service or repairs to the system are accomplished.

Professional Inspection Required


A professional inspection is required in the following cases:
  • In general, community and commercial septic systems must be inspected by a professional in Jefferson County. Authorized homeowners connected to a community septic system may inspect their own individual septic tank (and pump chamber if applicable) unless a maintenance contract or Homeowners Association Agreement requires a professional inspection.
  • At the time of sale of property or transfer of title an inspection by a professional is required to be on file in compliance with the required inspection frequency.
  • At the time of application for a building permit or other governmental actions such as land divisions, conditional use permit, boundary line adjustment, an inspection by a professional, compliant with the required frequency, must be on file. An inspection that involves more than a standard monitoring inspection may be needed for some building projects.
Please visit the certified professionals page for a current list of professionals operating in Jefferson County.

Monitoring Inspection Reports completed by professionals are filed to Online Responsible Management Entity. The information is available for viewing after it is ‘locked' into the system by the inspector. You can view reports that have been entered since June 2010 by going to the site and entering either your address or parcel number.

Additional Information


For more information, see Chapter 246-272A of the Washington State Code (WAC), On-Site Sewage System Rules and Regulations and Jefferson County Code 8.15 (PDF), Jefferson County On-site Sewage System Code.

A list of individuals certified to complete the inspections can be found on the certified professionals page.

For homeowners interested in becoming authorized to complete monitoring inspections on their own septic systems info can be found on the resources for homeowners page.