Associate/master installer

Certification exam 

Exams that cover the necessary knowledge for the associated and master installer certifications are offered by Public Health - Seatle & King County.

If you pass the exam, orientation interviews will be scheduled for successful candidates for the associate installer, master installer, and on-site system maintainer (OSM), Certificates of Competency.

If you fail the exam, you may re-take the exam. A new application and exam fee are required.

Exam process

Exams will be proctored during the first week of the month October to June. Applications must be submitted by day 15 of the previous month. Apply for exam at SkipThePaper.com. You can view submission instructions for the on-site sewage/septic system competency exam application. Exams will be held at the Eastgate Public Health office, 14350 SE Eastgate Way, Bellevue, WA 98007.  King County Septic program staff will contact you to schedule the exam start time.

Requirements for exam application

1. Proof of successful completion (within the previous 12 months) of a health officer recognized course of instruction in the basics of septic systems and installation of septic systems.

2 (Associate only). Proof that applicant is working under a master installer, such as a letter on company letterhead.

Associate installer exam content

• The installation permit process
• Requirements for backfill procedure(s)
• Setback requirements
• Specifications for septic tanks, pump chambers
• Various drainfield configurations
• Distribution boxes and sewage piping
• Soil depth requirements
• Recommended standards and required procedures for installation and repair of on-site sewage systems

Master installer exam content

• Strong comprehension of soil treatment of pathogens, total suspended solids, fats, oils, and grease, and nutrients
• Strong comprehension of the principles of on-site sewage treatment system design, installation, and maintenance
• Tank sizing requirements and construction specifications
• Setback requirements
• Soil types, nomenclature, and site implications
• Roles and responsibilities of master and associate installers and designers specified in codes
• Permitting processes for repairs and new development
• Trouble shooting failing systems
• Repair of septic systems
• Specifications of system sizing, including design of septic systems for gravity, pressure, and public domain systems
• Installation permit process

Certification renewal

All certifications expire on December 31 of each year. To renew professional certification for the following year, a certification renewal application and fee must be submitted by December 31.

Submit associate installer or master installer certification (renew) application on SkipThePaper.com. You can view registration instructions here.

Renewal deadline and late fees

View the current fee schedule (86.5 KB)

• All certificates of competency expire December 31 of each year.
• Applications for renewal are accepted annually beginning in November. Exam re-take is not required.
• For master/associate installer and OSMs: A late fee of 25% of the renewal amount will be charged for a renewal application received after January 15. The applicant may be required to re-take the exam if the renewal application is not submitted by January 15.
• All fees are non-refundable.

Requirements for certification renewal application

Associate installer

1. Proof of successful completion of at least 1 continuing education credit (CEU) during the previous calendar year. 1 CEU = 8 contact hours

Master installer

1. Proof of successful completion of at least 1 continuing education credit (CEU) during the previous calendar year. 1 CEU = 8 contact hours

2. Proof of State of Washington minimum bonding requirements and contractor’s liability for specialty or general contractor’s license.