Hexavalent Chromium: Filling Critical Knowledge Gaps to Inform Effective Rulemaking

Jun 5, 2019

Groundwater contamination in California brought public health concerns, media attention, and ultimately increased the regulatory burden for California water utilities in the form of a new and costly Hexavalent Chromium (Cr[VI]) maximum contaminant level. With a pressing need for research on Cr(VI) removal, it became apparent that WRF needed to focus the research on specific goals relevant to a broad number of utilities. This Research Area was established in 2012 to guide and fund specific research as identified by a Technical Advisory Committee comprised of experts from utilities, academia, government, and engineering consulting firms. As each project progressed, additional research needs became apparent, such as process optimization and residuals minimization. Residuals minimization is a critical issue that strongly influences selection of treatment technology, and it also exposes the need for redundant disposal options. Costs of compliance continue to be significant for many utilities, but the tools and recommendations resulting from this Research Area and affiliated research will help utilities of all sizes plan for and comply with their regulatory requirements.


Research Area Objectives

  1. Evaluate treatment for removing Cr(VI) from drinking water systems of various sizes with different water quality conditions and potential unintended consequences of treatment
  2. Develop cost information for Cr(VI) treatment and residuals management for observed water quality conditions and scenarios
  3. Investigate the potential for water treatment and distribution practices to impact Cr(VI) concentrations in finished and distributed drinking water


Research Area Synthesis Document

Refer to our Cr(VI) Synthesis Document to find out how the Research Area results fit into the Cr(VI) regulatory landscape.


Research Area Project Timeline and Value

Impact of Water Quality on Hexavalent Chromium Removal Efficiency and Cost

  • Timeline: 2012–2014
  • Total Project Value: $870,683
  • Research Area Objectives: Removal, Cost

Sources, Chemistry, Fate, and Transport of Chromium in Drinking Water Treatment Plants and Distribution Systems

  • Timeline: 2014–2017
  • Total Project Value: $478,412
  • Research Area Objectives: Other Impacts

Cost-Effective Cr(VI) Residuals Management Strategies

  • Timeline: 2014–2017
  • Total Project Value: $291,508
  • Research Area Objectives: Other Impacts

Bench-Scale Evaluation of Alternative Cr(VI) Removal Options for Small Systems

  • Timeline: 2013–2016
  • Total Project Value: $333,500
  • Research Area Objectives: Removal

Scoping Study to Review Contributions of Chromium to Drinking Water from Corrosion in the Distribution System

  • Timeline: 2014–2016
  • Total Project Value: $51,068
  • Research Area Objectives: Other Impacts

Cumulative Project Value for Research Area: $2,025,171


Projects Funded Outside of the Research Area Program that mees a Research Area Objective

Hexavalent Chromium Treatment with Strong Base Anion Exchange and Chemical Reductive Media

  • Year Completed: 2014
  • Funding Program: TC
  • RA Objectives: Removal, Other Impacts

Assessment of Single-Pass IX and Absorptive Media for Hexavalent Chromium Removal from Drinking Water

  • Year Completed: 2015
  • Funding Program: TC
  • RA Objectives: Removal

Development of a Uniform Approach to Prepare Drinking Water Hex Chrome Compliance Plans

  • Year Completed: 2019
  • Funding Program: TC
  • RA Objectives: Removal, Cost, Other Impacts

Evaluating Reduction Coagulation Filtration and Anion Exchange Brine Optimization for Cr(VI) Removal

  • Year Completed: 2016
  • Funding Program: TC
  • RA Objectives: Removal, Other Impacts

Sources, Fate and Treatment of Hexavalent Chromium

  • Year Completed: 2017
  • Funding Program: TC/FA
  • RA Objectives: Other Impacts



TC = Tailored Collaboration

FA = Focus Area

Project Status

Year Initiated: 2012

Year Completed: 2014


Advisory Committee Members

  • John Consolvo, City of Philadelphia
  • David Mazzera, CA Dept. of Public Health
  • Laurie McNeil, Utah State University
  • Matt Corson, American Water
  • Steve Bigley, Coachella Valley Water District
  • Bruce Macler, USEPA Region 9
  • Steve Via, American Water Works Association (AWWA)
  • Michelle DeHaan, Park City Water Department
  • Tom Sorg, USEPA
  • Robert Brownwood, City of Tulsa