National Primary Drinking Water Regulation for Perchlorate

On January 6, 2026, the EPA proposed a National Primary Drinking Water Regulation (NPDWR) for perchlorate, setting a health-based Maximum Contaminant Level Goal (MCLG) at 0.02 mg/L (20 µg/L). The agency is proposing enforceable Maximum Contaminant Levels (MCLs) at 0.02 mg/L, 0.04 mg/L, or 0.08 mg/L, and requires water systems to conduct monitoring, take mitigation actions if levels exceed the MCL, provide public notifications, and report to primacy agencies. Despite determining that the benefits do not justify the costs, the rule is mandated by a D.C. Circuit Court decision in NRDC v. Regan. Public comments are due by March 9, 2026, with PRA-related comments due by February 5, 2026.

PFAS Drinking Water Regulations

The EPA is extending compliance deadlines for PFOA and PFOS under the PFAS National Primary Drinking Water Regulation. A proposed rule to extend the compliance date to 2031 will be issued this fall, with a final rule expected in spring 2026. The agency is also exploring broader regulatory strategies, including effluent limitation guidelines (ELGs) for PFAS and liability reforms. The UCMR 5 data collection (2023–2025) has provided critical occurrence data, fueling ongoing regulatory development.

ADDITIONAL INFORMATION: Hank Naughton, Managing Partner, PFAS Cost Recovery Program, Napoli Shkolnik

Urgent $15 Billion PFAS Cost Recovery Program Update

Register your system in the settlement at www.napolilaw.com/nrwa-pfas. There is no obligation; Hank Naughton or Sam Wade will contact you to provide additional details and answer any questions you may have. Their contact information is below:

Sam Wade, Water Consultant: Swade@napolilaw.com | Cell: 1-580-917-1425

Hank Naughton, Managing Partner: HNaughton@napolilaw.com | Cell: 1-978-852-3643

Waters of the United States (WOTUS) Definition

The EPA and Army Corps of Engineers released a proposed rule on November 20, 2025, to narrow the definition of “waters of the United States” under the Clean Water Act, aligning with the Supreme Court’s Sackett v. EPA decision. Key changes include defining “relatively permanent” waters, requiring a “continuous surface connection” for wetlands, and excluding groundwater and ephemeral streams. The proposal would likely reduce federal jurisdiction, with only 19% of wetlands in the National Wetlands Inventory expected to be covered. Public comments were due by January 5, 2026, and a final rule is expected within six months.

Water Quality Certification (CWA Section 401) Revisions

On January 15, 2026, the EPA proposed updates to the water quality certification process under CWA Section 401, clarifying requirements for certification requests, scope, decision contents, modifications, and withdrawal/resubmittal processes. The rule also addresses “treatment as a State” (TAS) for tribes. A virtual public meeting is scheduled for January 28, 2026, with comments due by February 17, 2026. The rule aims to reduce regulatory uncertainty and improve consistency in the certification process.

Lead and Copper Rule Improvements (LCRI)

The federal government is finalizing a sweeping update to the Lead and Copper Rule, with key changes including tighter requirements for lead service line replacement, lower action levels for lead and copper, and more comprehensive testing in schools and childcare facilities. Planning for full replacement efforts must begin before 2026, with many systems required to map their service lines. These updates are critical for public health and infrastructure modernization.

Consumer Confidence Report (CCR) Rule Revisions

While enforcement begins in 2027, the first CCRs under revised rules will reflect 2026 water quality data. Key changes include making reports easier to understand, more accessible to non-English speakers, and requiring twice-yearly issuance by some systems. Reports will include clearer health risk explanations and more detailed lead information.

Industrial, Manufacturing or Transportation

Industrial facilities and construction sites are regulated by the Regional Water Quality Control Board (RWQCB) and State Water Resources Control Board (SWRCB) through general stormwater permits. Most businesses that store materials or process operations outdoors are required to obtain coverage under the SWRCB’s General Industrial Activities Stormwater Permit. These businesses are required to comply with the General Industrial Activities Stormwater Permit.

Construction

If your business conducts construction activities, including clearing, grading, stockpiling or excavation that results in soil disturbances of at least one acre, you are subject to the State Water Resources Control Board’s General Construction Activities Stormwater Permit.

Government

Cities and counties are regulated through permits issued by the Regional Boards. Since 1990, operators of large storm drain systems such as San Bernardino Counties have been required to:

• Develop a stormwater management program designed to prevent harmful pollutants from being dumped or washed by stormwater runoff, into the stormwater system, then discharged into local water bodies; and
• Obtain a National Pollutant Discharge Elimination System (NPDES) permit.

Rules and Regulations

The 1987 passage of the Water Quality Act established NPDES permit requirements for discharges of stormwater. The NPDES permit program controls water pollution by regulating point sources that discharge pollutants into waters of the United States.

To download copies of the Basin Plan, NPDES permit, Water Quality Management Plan, and other important documents, visit our Reference Materials section. (https://sbcountystormwater.org/government/resources/permittee-reference-materials/)

More Information

The NPDES permit is determined by which Regional Board oversees any given area. In the case of San Bernardino County, it is the Santa Ana Regional Water Quality Control Board. (https://www.waterboards.ca.gov/santaana/) This board is responsible for overseeing the County’s MS4 NPDES permit and ensuring compliance with the discharge of pollutants into receiving water bodies.

The Federal Water Pollution Control Act prohibits the discharge of any pollutant to navigate waters from a point source unless the discharge is authorized by a National Pollutant Discharge Elimination System (NPDES) permit.