Lists of on-site sewage system professionals
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
- OSS designers and professional engineers
Design new and replacement septic systems, submit applications for subdivisions and boundary line adjustments
- Master installers
Install new and replacement septic systems.
- On-site system maintainers
Inspect and maintain septic systems and make limited repairs.
- Certified liquid waste pumper/haulers
Pump waste from tanks and haul it to a wastewater treatment plant.
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:
Questions to ask your septic system professional
(We recommend you contact at least three professionals before choosing who to hire.)
- What is the price of the following? (some of these services may be included in one fee):
- Preliminary site evaluation
- Soil log digging
- Stub-out inspection
- Pressure test
- Installation inspection
- Backfill inspection
- As-built package
- Does this include the County fees?
- Does your company assist with recording a Notice on title?
- Do you charge extra for the Homeowner's manual?
- Do you charge for extra visits or consultations?
- How quickly do you submit the final record drawing after the septic system is installed?
- What is the price of the installation?
- Does this include electrical work?
- Does this include County fees?
- Does this include the final inspection?
- Does this include backfill labor and materials?
- How long is the bid good for and what does it include?
- Do you fill the tanks with water after installation?
- Does your company offer monitoring services, if not who do you recommend?
- Does your company try to prioritize weather-sensitive systems?
- What is your approximate schedule for installation from the time you receive the permit?
- Do you guarantee your work? What is your warranty period? Will you complete repairs if there is a problem?
TIP: For a repair, the installer should inspect the property, look at the soil logs, and determine cause of failure PRIOR to any proposals.
- What is the price of the pump-out? What does the pump-out include?
- If the septic tank is over 1,000 gallons, will it cost extra by the gallon?
- Do you offer any discounts (e.g. senior, new customer, etc.)?
- When will the report be entered in OnlineRME?
- Does this cost include digging to uncover the septic tank lid(s)? If not, do you charge by the foot? If not by foot, how much do you charge to dig out:
- 1 septic tank lid
- 2 septic tank lids
- Pump tank lid (if you have one)
- 1 septic tank lid
- Does this cost include dumping and County fees?
- Does this cost include inspection of the inlet and outlet baffles in the septic tank? Do you charge extra to clean the filter baffle?
- Is there an additional charge for the extra water and time required to pump a tank that has not been maintained properly (for example, pumped on a regular basis)?
- Do you regularly pump the pump tank? What is the charge for this service? 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.
TIP: Let the pumper know the size, type, accessibility of lids, age of house, and last time 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.