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Operators in training wearing yellow vests, eye protection and hard hats at a King County treatment plant. Note: photo was taken prior to Covid mask protocols. 2017 OIT class. Note: photo was taken prior to Covid mask protocols.

APPLY: 2023 Operator in Training (OIT)
Application deadline is March 5, 2023 (11:59 PM Pacific).

Open House Tour/Q&A for the OIT Program

  • Saturday, 2/18/23, South Treatment Plant (1200 Monster Rd SW, Renton)
  • 10:00-11:00 am
  • 1:00-2:00 pm
  • Please be on time (no late arrivals).
  • Wear sturdy, closed-toe walking shoes.
  • Tour will include navigating multiple stairways. This will give candidates a better understanding on the working environment or conditions of a Wastewater Treatment Plant.
  • Please note that there are no direct bus routes to the treatment plants.
  • A reliable mode of transportation or a way to arrive on time for your scheduled shift will be required.

Here is what you can expect if you are selected

Program Overview

We are looking to hire several Operator in Training (OIT) Program participants into six month short term temporary Utility Worker positions. These positions are essential paid on-the-job training positions that can lead to career service employment with King County Wastewater Treatment Division (WTD).

The initial six months in the OIT position will provide the successful candidate on-the-job and classroom training necessary to earn a Washington State Department of Ecology OIT Certification. Successful candidates who already possess a WA State OIT certification will work in the OIT role for six months as well, learning WTD plant operations and safety procedures. Those who earn their OIT Certification within their first six months may be invited to continue for an additional two years in the OIT position. After one year of wastewater treatment plant operation experience, candidates will earn their Washington State Wastewater Treatment Operator Group I certification. They can begin to apply for career service Wastewater Treatment Operator positions as they become available.

WORK SCHEDULES and LOCATIONS: The Wastewater Treatment Plants are operated 24/7. After twelve (12) weeks of a Monday-Friday, 7:00am-3:30pm weekday schedule in classroom training, all OIT’s will rotate through all the Wastewater Treatment Plants on day and rotating shift schedules. Day schedules for plant operations are four, 10-hour days. Shift schedules consist of two 11.7-hour day shifts, followed by two 11.7-hour night shifts, followed by four days off. Applicants must be available to work at ALL Wastewater Treatment locations and expected to work ALL assigned shift schedules. This position is overtime eligible; and employees do receive additional compensation for working rotating shifts and for night shifts..

These assignments may be located at any of King County Wastewater Treatment Facilities in Renton, Seattle or Snohomish County:

  • South Treatment Plant, 1200 Monster Road S.W., Renton, WA 98057 – this also includes our East off-site locations that consist of 20 pump stations and 41 structures – plus, be available to work at our 2 smaller wastewater treatment plants – Carnation and Vashon Island
  • West Point Treatment Plant, 1400 Discovery Park Blvd., Seattle, WA 98199 – this also includes our West off-site locations – which include 72 pump stations and regulators
  • Brightwater Treatment Plant, 22505 State Route 9 S.E., Woodinville, WA 98072

Within 6 months of Wastewater Treatment Training the OIT participants ARE REQUIRED to successfully pass the Washington State Department of Ecology Wastewater Operator in Training Certification exam . Once the participant achieves the State certification, they are eligible to move into the Term Limited Temporary position of an OIT and receive a wage increase.

2023 Hiring Process

  • Applications being taken online through March 5, 2023 (11:59 PM Pacific).
  • After the job posting closes, applicants will be asked to take an online written qualifying exam.
  • Applicants who successfully pass the written exam will be invited for an in-person hands-on test to be conducted at the South Treatment Plant (Renton).
  • Applicants who pass the written and hand-on test will be invited to an in-person interview (up to 30 minutes).
  • A WTD hiring team will process the interview scores, and forward a list of the top applicants to the hiring authority for approval.


  • Three months of classroom training
  • Wastewater Fundamentals Course work
  • Tours of King County Wastewater Treatment Facilities
  • In-person meetings with various staff from throughout the WTD
  • On the job training with certified wastewater treatment Operators
  • Team building exercises
  • Multiple field trips exploring a variety of facilities involved in wastewater treatment
  • Training on essential Operator skills, including but not limited to:
    • Forklift Driving
    • Defensive Driving
    • Confined Space Training
    • Hazardous Communications
    • Pumps 101
    • Plant hydraulic flows

In the field Job Training and Classroom

  • Technical Trainers Support
  • Supervisor support
  • Co-workers support


  • A well-trained, well-rounded WWTPO I (certified Washington State Wastewater Operator) within 1 year
  • Potential to obtain a King County Wastewater Career Service Wastewater Operator position
  • A motivated employee with energy, eagerness and who is excited to fill a position that is dedicated to protecting the health of our community and our environment
  • Fill a satisfying role that makes a difference
  • A Union Job providing a family living wage, excellent benefits, including a State sponsored pension for life
  • All in a workplace where supporting diversity and inclusion is the rule


2023 Utility Worker/Operator in Training Program starting wage rate:

2023 Operator in Training (OIT) Program – 6th month, program progression wage rate:

2023 Operator starting wage rate:

KC WTD --- Building Our Future Through Training

West Point Treatment Plant tour

South Treatment Plant tour