California Drinking Water Regulations: PFAS, Permits, Enforcement

California drinking water regulations are enforced by the State Water Resources Control Board (SWRCB) through its Division of Drinking Water (DDW), which permits public water systems, sets contaminant limits that in several categories go beyond federal standards, and pursues enforcement against systems that fall short. If you operate, oversee, or advise a public water system in the state, your obligations sit at the intersection of the California Safe Drinking Water Act, the federal Safe Drinking Water Act, and Title 22 of the California Code of Regulations. California law also declares that every resident has the right to safe, clean, affordable, and accessible drinking water, and directs state agencies to weigh that right when setting policies and grant criteria.1California Legislative Information. California Health and Safety Code 116270

Who Regulates Your Water System

The DDW is the primary regulator of public drinking water in California. It issues permits, conducts inspections, and enforces both state and federal drinking water law.2California State Water Resources Control Board. Drinking Water Program

Not every system deals with the DDW directly. Smaller systems with 200 or fewer service connections are usually regulated by local primacy agencies (LPAs), typically county health departments operating under agreements with the SWRCB. LPAs handle compliance monitoring, sanitary surveys, and day-to-day oversight for those systems.3California State Water Resources Control Board. Glossary – Local Primary Agency (LPA)

The U.S. Environmental Protection Agency retains backup authority. If California’s program fails to meet federal requirements, the EPA can step into enforcement or begin proceedings to withdraw the state’s primary enforcement responsibility.4Federal Register. National Primary Drinking Water Regulations Implementation Primary Enforcement Responsibility – Final Rule

Permit To Operate a Public Water System

No one can operate a public water system in California without a permit from the SWRCB. Applications must include engineering reports, proposed water sources, system design plans, and operational procedures. DDW review looks at water supply reliability, source protection, and the system’s ability to meet contaminant limits.5California State Water Resources Control Board. Safe Drinking Water Act Turns 50

A central piece of the review is technical, managerial, and financial capacity. Technical capacity means the infrastructure and staff expertise to treat and deliver safe water. Managerial capacity covers organizational structure, staffing, and customer communication. Financial capacity means the system can generate and manage enough revenue to remain in compliance over the long term.6EPA. EPA Regional Capacity Development Coordinator’s Handbook Systems that fall short generally cannot access Drinking Water State Revolving Fund assistance, so the fundamentals need to be in place before applying.

Expansions or infrastructure changes require an amended permit before the work proceeds. Temporary permits exist for emergencies but carry strict time limits and heightened monitoring. Annual regulatory fees fund DDW oversight, and failure to obtain or renew a permit can trigger a cease-and-desist order that shuts operations down until compliance is restored.

Contaminant Limits and Where California Goes Beyond Federal Law

California sets maximum contaminant levels (MCLs) for chemicals, metals, and microorganisms, and several of those limits are stricter than what federal rules require. The clearest current example is hexavalent chromium (chromium-6). California’s MCL of 0.010 mg/L took effect October 1, 2024, with compliance deadlines staggered by system size: systems with 10,000 or more connections must comply by October 1, 2026, mid-size systems by October 2027, and smaller systems by October 2028.7California State Water Resources Control Board. Hexavalent Chromium MCL (SWRCB-DDW-21-003) There is no separate federal MCL for hexavalent chromium, so this is a California-only obligation.

For arsenic, California’s MCL of 0.010 mg/L matches the federal standard.8California State Water Resources Control Board. MCLs, DLRs, PHGs for Regulated Drinking Water Contaminants9US EPA. Drinking Water Arsenic Rule History Where California diverges most clearly is in its public health goals (PHGs), which inform future rulemaking. California’s arsenic PHG is 0.000004 mg/L, far below the enforceable MCL, and those goals often shape the direction of later regulation.

Beyond chemical contaminants, secondary drinking water standards regulate taste, odor, and color. Monitoring frequency depends on the contaminant, system classification, and compliance history. Lead and copper testing follows a schedule that accounts for prior results and system size, using action levels rather than traditional MCLs. Laboratory analyses must be performed by facilities accredited under California’s Environmental Laboratory Accreditation Program (ELAP), and out-of-state labs must meet at least equally stringent standards to qualify for reciprocity.10Legal Information Institute. California Code of Regulations Title 22, 64808.10 – Reciprocity Accreditation

PFAS Rules in 2026

PFAS regulation is the fastest-moving area of California drinking water compliance. As of early 2026, California has not yet adopted enforceable MCLs for any PFAS compound, but enforceable obligations already exist from multiple directions.

Federally, the EPA finalized MCLs for six PFAS compounds in April 2024: 4.0 nanograms per liter (ng/L) for PFOA and PFOS, and 10 ng/L for PFHxS, PFNA, and GenX chemicals.11Federal Register. PFAS National Primary Drinking Water Regulation The federal compliance deadline is April 26, 2029, and the EPA has indicated it may extend that to 2031.12US EPA. EPA Announces It Will Keep Maximum Contaminant Levels for PFOA, PFOS In May 2025, the EPA also announced its intent to rescind the regulations for PFHxS, PFNA, GenX, and PFBS while keeping the PFOA and PFOS limits in place.13California State Water Resources Control Board. Agenda Item – Prioritization of 2026 Drinking Water Regulations

California has been building its own framework alongside. The DDW has set nonregulatory notification levels of 4.0 ng/L for PFOA and PFOS, and response levels of 10 ng/L for PFOA and 40 ng/L for PFOS. When monitoring detects PFAS above the response level, the system must take the source out of service, treat the water, or provide public notification.14California State Water Resources Control Board. PFAS – Per- and Polyfluoroalkyl Substances Drinking Water Systems In December 2025, the DDW issued a general order requiring community and nontransient-noncommunity systems to begin initial PFAS monitoring in line with federal requirements. Stage 1 rulemaking to formally adopt federal PFAS standards is planned for 2026, with a second stage for California-specific PFAS regulations to follow.13California State Water Resources Control Board. Agenda Item – Prioritization of 2026 Drinking Water Regulations

The practical point: PFAS monitoring obligations are already live. Systems that wait for a final state MCL before testing or planning treatment will be short on time once deadlines arrive.

Public Notification When Something Goes Wrong

Title 22 of the California Code of Regulations organizes violations into three tiers based on the severity of the health risk, with shorter deadlines for the more dangerous situations.

All notifications must follow SWRCB-mandated language describing the violation, potential health effects, corrective actions being taken, and what consumers should do. The SWRCB can also reclassify a violation upward and require Tier 1 notice for a situation that would otherwise fall under Tier 2.

Enforcement, Penalties, and Consolidation

Enforcement usually starts informally. The SWRCB and LPAs issue compliance assistance letters or notices of violation first, giving systems a chance to fix problems before penalties begin. Persistent violations move to formal compliance orders with specified deadlines.

For serious or repeated violations, the SWRCB can impose administrative penalties of up to $1,000 per day for each day a violation occurs, with separate penalties for each distinct violation.18California Legislative Information. California Health and Safety Code 116650 In cases of willful noncompliance or immediate public health danger, regulators can issue cease-and-desist orders, mandate emergency water supply provisions, or refer cases for civil or criminal prosecution. Federal penalties run substantially higher: the inflation-adjusted maximum for Safe Drinking Water Act violations assessed in 2025 or later reaches $71,545 per day for standard violations.19eCFR. Part 19 – Adjustment of Civil Monetary Penalties for Inflation

Mandatory Consolidation

Under SB 88, enacted in 2015, the SWRCB can order a public water system or a state small system in a disadvantaged community to consolidate with a nearby receiving system if it consistently fails to provide safe drinking water. Consolidation can be physical or operational, and the SWRCB can order interim extension of service while the consolidation is being arranged.20California Legislative Information. SB 88 Senate Bill – Enrolled The tool has seen increasing use in communities with chronic water quality failures, particularly in the San Joaquin Valley and other rural areas where small systems lack the resources for treatment upgrades.

Administrator Appointments

In extreme cases, the SWRCB can appoint an administrator to take over operations of a failing system under Health and Safety Code section 116686. Appointments are considered when necessary to provide affordable, safe drinking water to disadvantaged communities and to prevent fraud, waste, and mismanagement. In emergencies involving an imminent threat of serious harm, the SWRCB can appoint an administrator without the standard public comment process. Emergencies include system abandonment, loss of water supply due to drought, and acute contamination events.21California State Water Resources Control Board. Administrator Policy Handbook

Certified Operators

Every public water system must employ operators certified through the SWRCB’s Operator Certification Program. Certification runs across five grade levels for both treatment operators (T1 through T5) and distribution operators (D1 through D5), with higher grades required for more complex systems.22Legal Information Institute. California Code of Regulations Title 22, 63770 – Distribution System Staff Certification Requirements A small groundwater system with basic disinfection needs only a T1 or D1 operator, while a large surface water treatment plant or direct potable reuse facility requires a T5 operator.23Legal Information Institute. California Code of Regulations Title 22, 64669.35 – Operator Certification

Certification requires passing an examination, meeting education and experience prerequisites, and holding at least a high school diploma or equivalent. Federal guidelines allow states to substitute relevant training or on-the-job experience for formal education at certain levels.24EPA. Operator Certification Guidelines Implementation Guidance Continuing education is required to keep credentials current. Certified operators carry direct responsibility for regulatory compliance, water quality testing, and corrective actions at their systems.

A system that fails to employ properly certified personnel can face fines and permit revocation. Operators who falsify records or show gross negligence can be suspended or lose their certification permanently.

Challenging an Agency Decision

A water system or operator that disagrees with an enforcement action, permit denial, or certification decision has a defined path to challenge it. For enforcement orders issued by DDW staff, the first step is to petition the SWRCB itself for reconsideration within 30 days. That petition must be filed before the case can move to court.25California State Water Resources Control Board. California Safe Drinking Water Laws

SWRCB hearings run as quasi-judicial proceedings. A hearing officer or board panel presides, and parties can present expert testimony, submit technical reports, and cross-examine witnesses.26California State Water Resources Control Board. Hearings Program – Hearing Regulations The board can affirm, modify, or rescind the original action.

A system dissatisfied with the SWRCB’s final decision can file a petition for a writ of mandate in California Superior Court within 30 days. Courts generally defer to the agency’s expertise but will overturn a decision that lacks substantial evidence or reflects an abuse of discretion. For federal enforcement actions under the Safe Drinking Water Act, appeals go to the U.S. Court of Appeals with a 45-day filing deadline from the date of final agency action.27Office of the Law Revision Counsel. 42 USC 300j-7 – Judicial Review

Federal Funding To Meet the Rules

Meeting expanding requirements costs money, and several federal streams help. The Bipartisan Infrastructure Law created a $5 billion grant program for small and disadvantaged communities to address emerging contaminants, with appropriations running through federal fiscal year 2026. The program is administered through states on a noncompetitive basis and covers activities like contaminant evaluation, treatment installation, and household water quality testing.28EPA. Draft National Water Program Guidance FY 2025-2026

The Drinking Water State Revolving Fund also received supplemental appropriations through the Bipartisan Infrastructure Law, including an Emerging Contaminant Supplemental that states can use for principal forgiveness and grants tied to PFAS-related infrastructure projects. For systems facing hexavalent chromium treatment upgrades or PFAS remediation, these programs are the most accessible federal financial support. Eligibility generally requires the system to demonstrate adequate technical, managerial, and financial capacity, which is the same standard the DDW evaluates during permitting.