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Only individuals with Certificates of Competency or licenses are authorized to perform work and maintenance on septic systems. Contact one of the following septic professionals for any work that needs to be done on your septic system.

Lists of licensed and certified professionals in King County

On-site wastewater treatment system designer or professional engineer (agricultural, civil or sanitary)

Washington State Department of Licensing (DOL) administers licenses for designers and professional engineers. You can find them in the yellow pages or you may find out if the designer or professional engineer has their license by doing a license search on DOL's website as follows:

Access the DOL license search engine

Questions for owners

Please use these questions to gather the information you need when hiring someone to work on your septic system. We recommend contacting at least three septic professionals before deciding whom to hire. You may also contact our office if you have additional questions.

This information is also available in PDF format and in other languages below.

Design new and replacement septic systems, submit applications for subdivisions and boundary line adjustments, do preconstruction meetings with an installer, submit applications for water source applications and record drawings, do inspections of septic system installations, and conduct feasibility studies.

  1. What is the price of the following? (some of these services may be included in one fee):
    1. Preliminary site evaluation
    2. Soil log digging
    3. Design
    4. Stub-out inspection
    5. Pressure test
    6. Installation inspection
    7. Backfill inspection
    8. As-built package

  2. Does this include the County fees?

  3. Does your company assist with recording a Notice on title?

    *The Notice on Title is a document in which the owner acknowledges the property is served by a septic system and is responsible for its operation and maintenance.

  4. Do you charge extra for the Homeowner's manual?

  5. Do you charge for extra visits or consultations?

  6. How quickly do you submit the final record drawing after the septic system is installed?

  7. What is your turnaround time for returning calls and emails?
  1. What is the price of the installation?
    1. Does this include electrical work?
    2. Does this include County fees?
    3. Does this include the final inspection?
    4. Does this include backfill labor and materials?

  2. How long is the bid good for and what does it include?

  3. Do you fill the tanks with water after installation?

  4. Does your company offer monitoring services? If not, who do you recommend?

  5. Does your company try to prioritize weather-sensitive systems?

  6. What is your approximate schedule for installation from the time you receive the permit?

  7. Does your company assist in the Notice on Title that needs to be recorded?

    (The Notice on Title is a document in which the owner acknowledges the property is served by a septic system and is responsible for its operation and maintenance.)

  8. Do you guarantee your work? What is your warranty period? Will you complete repairs if there is a problem?

  9. Who is your certified master installer that will be on-site to oversee the install of the septic system?

  10. What is your turnaround time for returning calls and emails?

TIP: For a repair, the installer should inspect the property and determine the cause of failure PRIOR to any proposals.

  1. What will the OSM inspection include (e.g. checking baffles and for leaks, cleaning filters, structural integrity and drainfield checks, etc.)?

  2. Can I be present for the inspection? (We recommend that you track the work done by the maintainer and learn more about how your septic system is functioning.)

  3. Do you charge extra to uncover lids that are buried?

  4. What are the benefits to installing risers to the surface (if needed)?

  5. Do you offer any discounts (e.g. senior, new customer, etc.)?

  6. Does the inspection cost include County fees?

  7. When will the report be entered in onlineRME for viewing?

  8. If repairs are needed, can you perform the repairs? Can you do electrical repairs, or do you work with an electrician?

TIP: If a maintainer finds a problem with the septic system, you will need to get that fixed. You can hire anyone who is certified to do the type of work that is needed. You can find lists of certified professionals at

  1. What is the price of the pump-out? What does the pump-out include?

  2. If the septic tank is over 1,000 gallons, will it cost extra?

  3. Do you offer any discounts (e.g. senior, new customer, etc.)?

  4. When will the report be entered in OnlineRME?

  5. Does this cost include digging to uncover the septic tank lid(s)? If not, how much do you charge to dig out:
    1. 1 septic tank lid
    2. 2 septic tank lids
    3. Pump tank lid - If there is a pump tank, it should be pumped in addition to the septic tank, rinsed with a hose, and pumped dry. If the pump tank is very full, you may be charged an extra fee.

  6. Does this cost include dumping and County fees?

  7. Does this cost include inspection of the inlet and outlet baffles in the septic tank? Do you charge extra to clean the filter baffle?

  8. Is there an additional charge for the extra water and time required to pump a tank that has an unusual amount of scum or sludge?

TIP: Let the pumper know the size, type, accessibility of lids, age of the house, and last time the system was pumped. If you have a long-distance to pump over or will require pumping up a steep slope, provide the distance and elevation to the Pumper. The Pumper will determine whether the truck can provide this type of service.

Questions for owners in other languages:

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