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Reclaimed Water Infiltration Study

The LOTT Clean Water Alliance is conducting a multi-year study with the goal of providing local scientific data and community perspectives to help policymakers make informed decisions about future reclaimed water treatment and uses.


Addressing Community Questions

To address community questions about using reclaimed water to recharge groundwater, the LOTT Clean Water Alliance is conducting a multi-year study. Findings will help LOTT and our communities understand potential risks from infiltrating reclaimed water to groundwater and how to reduce those risks.

Why study reclaimed water? Each of us sends water down the drain every day at our homes and businesses. With that water, we also send chemicals down the drain from the many medicines and household and personal care products we use. The water must be collected and cleaned up before it is released back to the environment. It can be treated to various levels of quality, and some of it is treated to reclaimed water standards. This water can be reused in the community or infiltrated into the ground, where it eventually mixes with groundwater. Reclaimed water meets high water quality standards, but the standards do not address residual chemicals from medicines and household and personal care products.

What will the study involve? The study includes a scientific look at which chemicals, such as those from soaps, shampoos, household cleaners, medicines, and cosmetics, are present in reclaimed water and what happens to them when reclaimed water is allowed to infiltrate into groundwater. The study will also encourage community conversations about water quality, reclaimed water, groundwater recharge, residual chemicals, and related watershed issues. Together, the science and the community dialogue from the study will help inform decisions about how to treat and use reclaimed water in the future.

View Study Introductory Materials

Video Introduction to the Study

Study Framework


The study effort began in 2012 with consulting assistance from HDR Engineering Inc. The effort is divided into three phases.

  • Phase 1 is complete; it included background work to review current research and case studies from other parts of the country, forming an advisory structure for the study, including a Community Advisory Group, and developing a Public Involvement Plan.

  • Phase 2 is complete; it included developing the study design and scoping the work to be completed as part of Phase 3, the implementation phase of the study.

  • Phase 3 is underway; it involves field work, data analysis and modeling, and more public involvement. The study is expected to be complete in 2017.


Your input about the study is welcome! Please share your questions, concerns, or interests regarding the study or sign up to receive updates about study progress and opportunities for public involvement by clicking here.

Community Advisory Group

A Community Advisory Group was formed to assist the LOTT Alliance Board of Directors and study team to gain an understanding of community perspectives and questions, ensure the study is designed to address community concerns, and help identify effective ways to engage the public throughout the study. The group is currently in their third phase of work.

View Phase 3 Materials:

Meeting 3.1 – July 29, 2014

Meeting 3.2 – June 9, 2015

Mission and Roles – Phase 3

The group’s next meeting date has not yet been set, but is anticipated for early December 2015. Check back for more details. Members of the public are welcome to attend and observe meetings of the advisory group.

Current members of the Community Advisory Group are:

Maureen Canny
John Cusick
Lyle Fogg
Holly Gadbaw
Karen Janowitz
Bill Liechty
Scott Morgan
Pixie Needham

View Community Advisory Group Materials:

Final Report – Phase 2

Final Report – Phase 1

Questions regarding the Community Advisory Group can be directed to Lisa Dennis-Perez, LOTT Public Communications Manager, at (360) 528-5719 or send an email.

Design of the Study: Background and Framework

The study is designed to answer these questions:

What are the risks from infiltrating reclaimed water into groundwater because of chemicals that may remain in the water from products people use every day, and what can be done to reduce those risks?

To accomplish that, the study framework focuses on four key areas: water quality characterization; treatment effectiveness evaluation; risk assessment; and cost/benefit analysis.

View background information:

What is Reclaimed Water?

What is Infiltration?

What are Residual Chemicals?

Why the Study?

Study Structure

View videos on the design of Phase 3 work:

Part 1 Study Framework – Terms and Definitions

Part 2 Study Framework – Overview

Part 3 Study Framework – Study Activities

Study Products and Reports

Study work will result in a variety of products, resources, and reports. Check here occasionally to view additional materials as they become available.


State of the Science – Summary of the State of the Science, based on a review of existing scientific research regarding study topics.

Case Study Summary – Case studies for six different projects across the country that involve infiltrating reclaimed water into groundwater.

Study Scope of Work Phase 3 – Description of work associated with the implementation phase of the study.

Peer Review Panel Report, February 2014 – Final report from panel's review of the study design and draft Phase 3 scope of work.

Study Team Response to Panel – Responses to comments and recommendations made by Peer Review Panel regarding study design and draft scope.

Public Involvement

Public Involvement Plan – A guide that will be adjusted as the study progresses to effectively engage the public, gather input and feedback, and encourage community dialogue about the study and related issues.

Focus Group Report – Summary of three citizen focus groups conducted in the fall of 2013 to learn how best to communicate about the study and the technical topics involved.

Public Opinion Phone Survey Report – Summary of a phone survey conducted in early 2013 of 400 residents to gain an understanding of public awareness, knowledge, interest, and perceptions regarding water, wastewater, reclaimed water, groundwater recharge, and related issues.

Public Opinion Interviews Report – Summary of structured interviews conducted in early 2013 with 53 community members to gauge awareness, interest, and opinions about study related issues.


Here is a list of additional resources (presentations, documents, studies, and reports) that may be of interest. Check here occasionally as this list will be updated over time.

Videos from 2012 Symposium on Compounds of Emerging Concern - LOTT and the Washington State Department of Health co-sponsored a science symposium about compounds of emerging concern in March 2012 that featured five internationally-renowned experts in the field of chemicals in the environment.:

Safe and Sustainable Water Reuse – Shane A. Snyder, Ph.D, Professor of Chemical and Environmental Engineering in the University of Arizona's College of Engineering and Co-Director of the Arizona Laboratory for Emerging Contaminants

Toxicology and Risk Assessment for Emerging Contaminants – Richard C. Pleus, Ph.D, Toxicologist and Director of Intertox, Inc.

Margins of Exposure from Pharmaceuticals, Consumer Products, EDCs, and Other Chemicals – Joseph A. Cotruvo, Ph.D, President of Joseph Cotruvo & Associates

Fate and Transport of Compounds of Emerging Concern During Managed Aquifer Recharge – Jörg E. Drewes, Ph.D, Associate Professor of Environmental Science and Engineering and Director of the Advanced Water Technology Center at the Colorado School of Mines

Regulatory Issues and EPA Efforts Regarding Water – Robert Bastian, Senior Environmental Scientist with the Office of Wastewater Management at the U.S. Environmental Protection Agency in Washington, D.C.

Question and Answer Session with All Five Presenters – Symposium speakers respond to questions from the audience about their presentations and compounds of emerging concern.

Public Comment

LOTT welcomes public comment and input about these issues. You are invited to share any questions, concerns, or interests you may have regarding reclaimed water, residual chemicals, groundwater recharge, the Reclaimed Water Infiltration Study, or related issues. Comments can be submitted by email by clicking here .

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