LOTT Clean Water Alliance

Reclaimed Water Infiltration Study


Project Update

The NWRI independent advisory panel met in Olympia on October 23, 2019. LOTT's Science Task Force made presentations to the panel on topics that included groundwater modeling, fate and transport analysis, and risk assessment.

A report on the meeting will be published here when it is available.

About the Project

LOTT manages wastewater for approximately 118,000 people in the urban areas of Lacey, Olympia, and Tumwater in Thurston County, Washington. Since 2006, LOTT has produced reclaimed water that is either used for irrigation and other non-drinking purposes, or sent to infiltration basins where it recharges groundwater. The long-range plan for meeting future wastewater needs centers on producing more reclaimed water and recharging groundwater.

LOTT built a Reclaimed Water Satellite System that can produce up to 1.5 million gallons per day (mgd) of reclaimed water. The system includes the Martin Way Reclaimed Water Plant, which uses a membrane bioreactor for primary, secondary, and tertiary treatment to meet Washington State's Class A Reclaimed Water standards.


The water is piped to the Hawks Prairie Reclaimed Water Ponds and Recharge Basins, where it circulates through five constructed wetland ponds that also serve as a public park and ecosystem for local wildlife. Then the water flows into recharge basins to infiltrate into the aquifer.

LOTT also produces up to 1.5 mgd of Class A Reclaimed Water at its Budd Inlet Treatment Plant using sand filter technology. Most of this reclaimed water is used for irrigation, toilet flushing, water features, and process uses within the treatment plant.

Why an Independent Advisory Panel? 

Community members raised questions and concerns about residual chemicals from pharmaceuticals and personal care products that may remain in reclaimed water, and what happens to those chemicals when reclaimed water is used to recharge groundwater.


To address these questions, LOTT has begun a multi-year scientific study to:

  1. Provide scientific data and community perspectives to help policymakers make informed decisions about future wastewater and reclaimed water treatment and uses.

  2. Ensure that the scientific study and public involvement processes are credible, objective, transparent, responsive, and responsible.

  3. Foster meaningful, community-wide dialog about water quality, reclaimed water, groundwater recharge, risk assessment, and related watershed issues.​


  • City of Lacey Water Resources

  • City of Olympia Water Resources

  • City of Tumwater Water Resources

  • Washington State Department of Ecology: Reclaimed Water

  • Washington State Department of Health: Reclaimed Water

  • LOTT Clean Water Alliance: Programs

  • LOTT Reclaimed Water Infiltration Study


National Water Research Institute

Suzanne Sharkey, Water Resources Scientist and Project Manager

ssharkey@nwri-usa.org or (714) 378-3278


Panel Meeting Reports

Panel Meeting 1 for the LOTT RWIS was held in February 2014 at LOTT's administrative offices in Olympia.  Download the Panel's Meeting 1 Report. 


Panel Meeting 2 for the LOTT RWIS was held in November 2017 at LOTT's administrative offices in Olympia. The meeting included a site visit to see the infiltration basins.


During the meeting, the following reports and presentations were discussed:

  • NWRI Panel Meeting Introduction (Presentation)

  • LOTT RWIS Overview (Presentation)

  • Draft Hydrogeologic Characterization (Report)

  • Hydrogeologic Characterization (Presentation)

  • Draft Tracer Test Work Plan (Report)

  • Tracer Test Work Plan (Presentation)

The Panel documented their recommendations in the Meeting 2 Panel Report. In addition, the LOTT RWIS Study Team responded to the Panel's recommendations

About the Panel

In 2013, LOTT Clean Water Alliance (LOTT) contracted with NWRI to provide a credible, third-party, science-based review of a Reclaimed Water Infiltration Study (RWIS) proposed by LOTT. NWRI appointed local and national water industry experts to an Independent Advisory Panel (Panel). 

The Panel advises LOTT by:

  • Providing expert peer review of the technical, scientific, and regulatory aspects of LOTT's Reclaimed Water Infiltration Study (RWIS).

  • Reviewing the work products, such as draft work plans, technical memos, and reports that are created by the LOTT Project Team.

  • Providing feedback on these work products.

  • Considering findings from similar completed or ongoing efforts.

  • Developing the most informed recommendations.


After each meeting, the Panel prepares a report that offers the Panel’s findings and recommendations on technical, scientific, and regulatory aspects of the Project that were discussed during the meeting. Reports from Meeting 1 and 2 are archived at the bottom of this page. Meeting 3 is tentatively planned for 2019. 

The Panel comprises six experts in disciplines related to the infiltration of reclaimed water, including water reuse and public health criteria, human and environmental toxicology, environmental hydrogeology, environmental health, and other relevant fields. Panel members are:

  • Panel Chair: James Crook, PhD, PE, Water Reuse and Environmental Engineering Consultant (Boston, MA)

  • Richard Bull, PhD, MoBull Consulting (Richland, WA)

  • Edward Kolodziej, PhD, University of Washington (Seattle, WA)

  • Michael Kenrick, PE, LHG, GeoEngineers (Redmond, WA)

  • John Stark, PhD, Washington State University (Puyallup, WA)

  • David Stensel, PhD, PE, University of Washington (Seattle, WA)

Click to download a PDF containing brief biographies of the Panel members.

LOTT Panel meeting in Olympia, Washington, on October 23, 2019.

National Water Research Institute

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