A large-scale, multi-year, scientific study
The effort began in 2012 with an extensive planning effort to gather community input and design a study to address key community questions. HDR Engineering was hired to assist with the study.
The implementation phase of the study is an ambitious multi-year effort made up of four main tasks that involve extensive planning, field work, analysis, reporting, and public involvement. Preparations for each task of the study are complex and take a considerable amount of time. Each task requires distinct phases of field work and analyses, and completion can span a year or more. Updates on study progress are provided intermittently when there are new developments to report.
Study Updates
Check here for occasional updates on study activities or sign up to receive email updates.
- May 2021 (PDF)
- June 2020 (PDF)
- November 2019 (PDF)
- January 2019 (PDF)
- January 2018 (PDF)
- October 2017 (PDF)
- May 2016 (PDF)
- May 2015 (PDF)
Study Tasks
The four main study tasks are described below, with results from each task posted as they become available.
Task 1: Water Quality Characterization – completed in 2017
Test groundwater, surface water, wastewater, and reclaimed water in the Hawks Prairie and Tumwater study areas for residual chemicals.
- Water Quality Characterization Fact Sheet (PDF) – A general overview of Task 1 activities and findings.
- Residual Chemicals in Reclaimed Water, Groundwater, and Surface Water (PDF) – A high level summary and comparison of results from the three Task 1 technical memos.
Task 2: Treatment Effectiveness Evaluation – completed in 2022
Analyze where reclaimed water infiltrated at the Hawks Prairie site goes, how quickly the water travels, and how the water quality changes over time.
- Treatment Effectiveness Evaluation Fact Sheet (PDF) – An overview of Task 2 activities and findings.
Task 3: Risk Assessment – completed in 2022
Evaluate relative risks to people and the environment that may result from infiltrating reclaimed water to replenish groundwater.
- Risk Assessment Fact Sheet (PDF) – An overview of Task 3 activities and findings.
Task 4: Cost/Benefit Analysis – completion expected in 2022
Consider long-term costs and benefits of various options for managing reclaimed water, including various levels of treatment and alternative uses of the water.
