Metal DLRs

This rulemaking is in progress.

Inquiries regarding the contents of these regulations may be directed to Bethany Robinson (Bethany.Robinson@waterboards.ca.gov) and Melissa Hall (Melissa.Hall@waterboards.ca.gov).

• Notice of Proposed Rulemaking Published: TBD
• Close of the 45-Day Public Comment Period: TBD
• Date of Scheduled Public Hearings: TBD
• Date filed with Office of Administrative Law: TBD
• Approved by Office of Administrative Law: TBD
• Filed with the Secretary of State: TBD
• Effective Date: TBD
• Pre-Rule Making Workshop
• Notice
• Presentation

Not all documents are available online. To request a document, email DDWRegUnit@waterboards.ca.gov.

Documents Relied Upon

1. Code of Federal Regulations. (2025). 40 C.F.R. 141.23-141.41, 141.66, and 141.89 (7-1-2025 ed.).
2. Eaton, A. (2022, November 3). Metal DLR Workshop Comment. 
3. ELAP. (2025, October 1). Table 103: Toxic Chemical Elements in Drinking Water. Environmental Laboratory Accreditation Program.
4. OCWD. (2022, November 2). Metal DLR Workshop Comment. Orange County Water District. 
5. SWRCB. (2021). November 2021 Laboratory Survey Responses. State Water Resources Control Board.
6. SWRCB. (2022a). December 2022 Laboratory Survey Responses. State Water Resources Control Board.
7. SWRCB. (2022b). February 2022 Laboratory Survey Responses. State Water Resources Control Board.
8. SWRCB. (2022c). Metal DLRs Pre-rulemaking Workshop on November 3, 2022. State Water Resources Control Board. Retrieved from https://www.waterboards.ca.gov/drinking_water/certlic/drinkingwater/docs/MetalsDLRWorkshop_slidedeck_Nov2022.pptx.
9. SWRCB. (2025a). October 2025 Laboratory Survey Responses. State Water Resources Control Board.
10. SWRCB. (2025b). State Water Resources Control Board Resolution No. 2025-0006: Adopting the Prioritization of Drinking Water Regulations Development for Calendar Year 2025. State Water Resources Control Board. Retrieved from https://www.waterboards.ca.gov/board_decisions/adopted_orders/resolutions/2025/rs2025-0006.pdf. 
11. SWRCB. (2026a). March 2026 Laboratory Survey Responses. State Water Resources Control Board.
12. SWRCB. (2026b). Safe Drinking Water Information System (SDWIS) and Water Quality Information Replacement (WQIR) Databases. State Water Resources Control Board. Retrieved 2026.
• Antimony
• Arsenic
• Beryllium
• Cadmium
• Iron
• Lead
• Manganese
• Mercury
• Nickel
• Silver
• Thallium
• Zinc
13. U.S. EPA. (1987, July 8). National Primary Drinking Water Regulations: Synthetic Organic Chemicals; Monitoring for Unregulated Contaminants; Final Rule. 52 Federal Register, p. 25699. Retrieved from https://archives.federalregister.gov/issue_slice/1987/7/8/25685-25734.pdf#page=6. 
14. U.S. EPA. (2000, December 7). National Primary Drinking Water Regulations; Radionuclides; Final Rule. 65 Federal Register, p. 76708. Retrieved from https://www.federalregister.gov/documents/2000/12/07/00-30421/national-primary-drinking-water-regulations-radionuclides-final-rule#print. 
15. U.S. EPA. (2009). Analytical Feasibility Support Document for the Second Six-Year Review of Existing National Primary Drinking Water Regulations. p. ii. Retrieved from https://www.epa.gov/sites/default/files/2014-12/documents/815b09003.pdf#page=4. 
16. U.S. EPA. (2015). UCMR 4 Laboratory Approval Requirements and Information Document, Version 1.0. p. 13. Retrieved from https://www.regulations.gov/document/EPA-HQ-OW-2015-0218-0057.
17. U.S. EPA. (2016). Definition and Procedure for the Determination of the Method Detection Limit, Revision 2. p. 1. Retrieved from https://www.epa.gov/sites/default/files/2016-12/documents/mdl-procedure_rev2_12-13-2016.pdf#page=3. 
18. U.S. EPA. (2023). PFAS National Primary Drinking Water Regulation. 88(60) Federal Register, p. 18638 - 18754. Retrieved from https://www.govinfo.gov/content/pkg/FR-2023-03-29/pdf/2023-05471.pdf.