Hexavalent Chromium MCL (SWRCB-DDW-21-003)

Initial 45-Day Comment Period

Notice of Proposed Rulemaking, Public Hearing, and 45-day Notice Period to Consider Proposed Hexavalent Chromium MCL Regulation (English | Español)

• Revised Notice of Proposed Rulemaking | Español
• Second Revised Notice of Proposed Rulemaking
• Third Revised Notice of Proposed Rulemaking

Initial Statement of Reasons (ISOR) - ISOR Errata

• ISOR Attachment 1: Cost Tables
• ISOR Attachment 2: Standardized Regulatory Impact Assessment (SRIA) and Cost Estimating Methodology (updated)
• ISOR Attachment 3: Other Chemicals Above the PHG
• ISOR Attachment 4: DLR Surveys Summary
• ISOR Attachment 5: Cost Estimates for Individual Sources

Text of Originally Proposed Regulations

• U.S. EPA Method 218.6
• U.S. EPA Method 218.7

Office of Administrative Law (OAL) Notices:

• Notice Register Index, OAL Notice No. Z2023-0606-03
• California Regulatory Notice Register 2023, Volume No. 24-Z, pp. 783-804

Administrative Procedure Act Public Hearing

Public Hearing held on August 2, 2023

• Agenda Item, Item 5 (English | Español)
• Video Recording of Public Hearing (English | Español)
• Staff PowerPoint Presentation (English | Español)

First 15-Day Comment Period

Notice of Public Availability of Changes to Proposed Regulations (English | Spanish)

• Revised Text of Proposed Regulations
• Addendum to Initial Statement of Reasons (ISOR)

Second 15-Day Comment Period

Notice of Public Availability of Additional Documents Relied Upon (English | Español)

• OEHHA. (2023). Public Review Draft of a Proposed Health-Protective Concentration for the Noncancer Effects of Hexavalent Chromium in Drinking Water. California Environmental Protection Agency, Office of Environmental Health Hazard Assessment.
• SWRCB.(2024). Consolidation and Alternatives Analysis. State Water Resources Control Board.
• Attachment 1

External Scientific Peer Review

• Request for Peer Review
• Peer Reviewer Responses
• Reviewer 1
• Reviewer 2
• Reviewer 3
• State Water Board Responses to Reviewers

California Environmental Quality Act (CEQA)

• Notice of Preparation of a Draft Program Environmental Impact Report
• Draft Environmental Impact Report
• Appendix A
• Appendix B
• Appendix C
• Appendix D
• Appendix E
• Notice of Availability of Draft Environmental Impact Report
• Notice of Completion of Draft Environmental Impact Report
• Final Environmental Impact Report
• Revised Appendix A
• Revised Appendix C
• New Appendix F

An Excel List of Materials and Documents Relied Upon is available. However, not all documents are available online. To request a document, email Bethany.Robinson@waterboards.ca.gov.

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• Agilent Technologies, Inc. (2023). Signal, Noise, and Detection Limits in Mass Spectrometry.
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• Aqua Metrology Systems. (2021). City of Los Banos, California. Safeguard H2O Pilot Report.
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• Association for the Advancement of Cost Engineering (AACE). (2016). Cost Estimate Classification System – As Applied in Engineering, Procurement, and Construction for the Process Industries. AACE International Recommended Practice No. 18R-97. AACE International.
• Blute, N.; Wu, X.; Imamura, G.; Song, Y.; Porter, K.; Cron, C.; Fong, L.; Froelich, D.; Abueg, R; Henrie, T.; Ramesh, S.; Vallejo, F. (2015a). Assessment of Ion Exchange, Adsorptive Media, and RCF for Cr(VI) Removal. Water Research Foundation: Web Report #4423.
• Blute, N.; Wu, X.; Cron, C.; Fong, L.; Froelich, D.; Abueg,R. (2015b). Microfiltration in the RCF Process forHexavalent Chromium Removal from Drinking Water. Water Research Foundation: Web Report #4365.
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• California Manufacturers and Technology Association & Solano County Taxpayers Association v. State Water Resources Control Board. (2017). Super. Ct., Sacramento County,Case No. 34-2015-80001850.
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• Hausladen, D. M.; Alexander-Ozinskas, A.; McClain, C.; Fendorf, S. (2018). Hexavalent Chromium Sources and Distribution in California Groundwater. Environmental Science & Technology, 52(15), 8242–8251.
• Hazen and Sawyer (2013). Hexavalent Chromium Removal Research Project to the California Department of Public Health. City of Glendale Water & Power.
• Kahn, H.D.; Stralka, K. (2009). Estimated daily average per capita water ingestion by child and adult age categories based on USDA's 1994–1996 and 1998 continuing survey of food intakes by individuals. Journal of Exposure Science & Environmental Epidemiology, 19(4),396–404.
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• McNeill, L.S.; McLean, J.E.; Parks, J.L.; Edwards, M.A. (2012). Hexavalent chromium review, part 2: Chemistry, occurrence, and treatment. Journal - American Water Works Association, 104: E395-E405.
• Mohamed, A.M.O.; Maraqa, M.; Al Handhaly, J. (2005). Impact of land disposal of reject brine from desalination plants on soil and groundwater. Presented at the Conference on Desalination and the Environment, Santa Margherita, Italy, 22-26 May 2005. European Desalination Society.
• Najm, I.; Brown, N.P; Seo, E.; Gallagher, B.; Gramith, K.; Blute, N.; Wu, X.; Yoo, M.; Liang, S.; Maceiko, S.; Kader, S.; Lowry, J. (2014). Impact of Water Quality on Hexavalent Chromium Removal Efficiency and Cost. Web Report #4450.
• Najm, I.; Romero-Maraccini, O.; Maraccini, P. A.; Askenaizer, D.; Gallagher, B. (2017). Cost-Effective Cr(VI) Residuals Management Strategies. Web Report #4556.
• North Star Water Treatment Systems. (2016). Model NSRO42C4 Installation and Operation Manual. Accessed January 24, 2022.
• OEHHA. (2011). Public Health Goals for Chemicals in Drinking Water, Hexavalent Chromium, California Environmental Protection Agency, Office of Environmental Health Hazard Assessment, July 2011.
• OEHHA. (2023). Public Review Draft of a Proposed Health-Protective Concentration for the Noncancer Effects of Hexavalent Chromium in Drinking Water. California Environmental Protection Agency, Office of Environmental Health Hazard Assessment.
• Parks, J. L.; Mantha, A.; Edwards, M.; Kommineni, S.; Shim,Y.; Porter, K.; & Imamura, G. (2017). Bench-Scale Evaluation of Alternative Cr(VI) Removal Options for Small Systems (Project #4561). Water Research Foundation.
• Pierri, Agustin (2021). "Re: Cr6 MRLs." Received by Eric Miguelino.
• Puronics Water Systems, Inc. (2019). Performance Data Sheet Model: Micromax 6500 TFC. Accessed January 27, 2023.
• Rad, S.A.M.; Mirbagheri, S.A.; Mohammadi, T. (2009). Using Reverse Osmosis Membrane for Chromium Removal from Aqueous Solution. World Academy of Science: Engineering and Technology 57.
• Seidel, C.J.; Najm, I.N.; Blute, N.K.; Corwin, C.J.; Wu, X.(2013). National and California treatment costs to comply with potential hexavalent chromium MCLs. Journal-AWWA, 105.
• Seidel, C.; Gorman, C.; Ghosh, A.; Dufour, T.; Mead, C.; Henderson, J.; Li, X.; Darby, J.; Green, P.; McNeill,L.; Clifford, D. (2014). Hexavalent Chromium Treatment with Strong Base Anion Exchange. Water Research Foundation: Web Report #4488.
• Servapure. (2022). ResinTech WBMP, Weak Base Anion Exchange Resin, 1 cubic foot. Accessed September 27, 2022.
• SWRCB. (2017). SBDDW-17-003 Point-of-Use and Point-of Entry Treatment—Permanent Regulations Attachment B Cost Estimating Methodology. State Water Resources ontrol Board.
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• SWRCB. (2021c). Water Quality Information Replacement (WQIR) database. State Water Resources Control Board.Accessed July 27, 2021 (note that this is a database that cannot be transmitted electronically; a printout of the data used can be provided).
• SWRCB. (2021d). Residential Water Treatment Devices. State Water Resources Control Board. Accessed June 2021.
• SWRCB. (2021e). Peer Review Request, Peer Review, and Peer Review Responses for Best Available Technologies (BAT) for Hexavalent Chromium Treatment.
• SWRCB. (2021f). Notification of Assembly Bill (AB52) Consultation Opportunity, Pursuant to Public Resources Code Section 21080.3.1 for the State Water Resources Control Board Adoption of a Regulation for the Hexavalent Chromium Maximum Contaminant Level (Project).
• SWRCB. (2021g). Failing Water Systems: The Human Right to Water (HR2W) List Criteria.
• SWRCB. (2022a). 2022 Drinking Water Needs Assessment: Affordability Assessment. Attachment D1: 2022 Affordability Assessment Data and Results.
• SWCRB. (2022b). State of California Drinking Water State Revolving Fund Intended Use Plan: State Fiscal Year 2022-23.
• SWRCB. (2022c). Notice of Public Workshop and Opportunity for Public Comment on Administrative Draft Hexavalent Chromium Maximum Contaminant Level.
• SWRCB. (2022d). Hexavalent Chromium Workshop Public Comments.
• SWRCB. (2023). California Drinking Water State Revolving Fund Interest Rate History.
• SWRCB. (2024). Consolidation and Alternatives Analysis. State Water Resources Control Board.
• Attachment 1
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• U.S. Bureau of Labor Statistics. (2020c). Occupational Employment and Wages, May 2020, 47-2515 Plumbers, Pipefitters, and Steamfitters.
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• U.S. Bureau of Labor Statistics. (2022d). Producer Price Index by Commodity: Waste Collection and Remediation Services [WPU50]. Retrieved from FRED, Federal Reserve Bank of St. Louis.
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• U.S. EPA. (2011). Method 218.7: Determination of Hexavalent Chromium in Drinking Water by Ion chromatography with Post-Column Derivatization and UV-Visible Spectroscopic Detection.
• U.S. EPA. (2013). EPA's recommendations for enhanced monitoring for Hexavalent Chromium (Chromium-6) in Drinking Water.
• U.S. EPA. (2017). Cost Estimation: Concepts and Methodology. United States Environmental Protection Agency, Office of Air Quality Planning and Standards.
• U.S. EPA. (2021a). Chromium in Drinking Water. United States Environmental Protection Agency, Office of Ground Water and Drinking Water.
• U.S. EPA. (2021b). Work Breakdown Structure-Based Cost Model for Anion Exchange Drinking Water Treatment. United States Environmental Protection Agency, Office of Ground Water and Drinking Water.
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