More communities than ever are investigating the feasibility of undertaking potable and non-potable reuse projects to increase their available water supply and prepare for periods of drought.

By Larry Schimmoller and Mary Jo Kealy, CH2M HILL

Larry Schimmoller and Mary Jo Kealy will present their paper “Potable And Non-Potable Reuse: How Much Does It Really Cost?” on Wednesday, June 12 at 2:30 p.m., during the American Water Works Association’s Annual Conference and Exposition (ACE 13), in Denver, Colorado.  Learn more about CH2M HILL’s ACE 13 2013 participation and technical sessions.

Water scarcity, population growth and climate change are modern realities that are increasingly drawing attention to water reuse projects worldwide.  More communities than ever are investigating the feasibility of undertaking potable and non-potable reuse projects to increase their available water supply and prepare for periods of drought.  The costs associated with implementing a reuse project is a critical factor in this evaluation.  Our presentation will offer actual construction and operating costs collected from numerous full-scale reuse plants currently operating throughout the United States and Australia.

The ongoing WateReuse Research Foundation Project 10-01 “The Cost of Over-Treating Reclaimed Water” examines the sustainability of various levels of treatment for potable and non-potable reuse applications.  As part of this project we performed a triple bottom line (TBL) analysis that included financial, environmental, and social elements to help assure that the appropriate treatment process is applied for the intended use without expending unnecessary funds or adversely impacting the environment.   Included in this research is an extensive survey of utilities currently practicing water reuse to collect full-scale construction and operating cost data.

The potable reuse plants examined are producing water for groundwater recharge, seawater intrusion barrier and surface water augmentation.  Treatment technologies used at these potable reuse plants included microfiltration (MF), reverse osmosis, ultraviolet (UV) advanced oxidation, lime softening, filtration and granular activated carbon adsorption.

Non-potable reuse plants examined are using water for landscape irrigation, industry, and commercial uses.  Treatment technologies used at these non-potable reuse plants included MF, coagulation, sedimentation, granular media filtration, UV disinfection, and chlorine disinfection. In addition to cost information, detailed water quality data and design criteria information from each plant was also collected because of the significant impact these parameters can have on costs.

Probable reasons for cost differences between plants will be explored and preliminary unit costs for new potable and non-potable reuse plants will be presented.   This information will allow water practitioners interested in implementing or expanding a reuse system to conceptually estimate treatment costs.  In addition, comparison of costs among treatment processes used for the same reuse application will assist in the selecting the most appropriate treatment solution.

Mr. Schimmoller is a Vice President and senior principal technologist with CH2M HILL’s Water Business Group as well as CH2M HILL’s Global Technology Leader for water reuse. He has extensive experience in planning, piloting, process selection, design, and construction of water treatment and water reuse projects.

Dr. Kealy has more than 30 years of experience as a natural resource economist with specialized expertise in natural resource and environmental economics, benefit-cost analysis, micro-economic and macro-economic theory and public economics. As senior economist in the policy office at the U.S. EPA, she conducted research and was a technical advisor to the Assistant Administrator of Policy and the program offices including the Office of Water, Office of Solid Waste and Emergency Response, and Office of Pollution Prevention and Toxic Substances.