What Is the California Safe Drinking Water Act?

The California Safe Drinking Water Act is the state law, codified in the Health and Safety Code beginning at Section 116270, that sets the rules for how public water systems deliver clean drinking water. It covers which systems are regulated, what contaminants are allowed and at what levels, how water must be tested, when customers must be told about problems, and what happens to providers that fall short. Serious violations can carry civil penalties up to $25,000 per day, and some conduct is charged as a felony.

Which Water Systems the Law Covers

The Act reaches any “public water system” that delivers water for human consumption through pipes or other built conveyances and either has 15 or more service connections or regularly serves at least 25 people daily for at least 60 days a year.¹ That pulls in municipal utilities, privately owned water companies, mobile home parks, apartment complexes, and homeowner associations that cross those thresholds.

California divides those systems into categories that determine how much regulation applies. A community water system serves at least 15 connections used by year-round residents or regularly serves 25 or more year-round residents. A transient noncommunity water system serves places like restaurants, gas stations, and campgrounds where the same 25 people are not present for more than six months a year.¹ Both types must meet treatment and monitoring requirements, but community systems face the most demanding obligations because they serve permanent populations.

Private wells that serve a single household fall outside the Act. Local health departments may impose their own rules on private wells, but the state Safe Drinking Water Act does not reach them.

Day-to-day enforcement sits with the State Water Resources Control Board (SWRCB) and its Division of Drinking Water (DDW), which exercise the primacy authority California holds under the federal Safe Drinking Water Act. California often sets stricter standards than the federal baseline, including notification and response levels for contaminants EPA has not yet regulated.

Water Quality Standards and Testing

Title 22 of the California Code of Regulations sets maximum contaminant levels (MCLs) for heavy metals, volatile organic compounds, and microbial pathogens.² An MCL is the highest concentration of a contaminant allowed in delivered drinking water. Exceeding one triggers reporting, customer notification, and corrective-action obligations.

Surface water sources such as reservoirs and rivers must receive multibarrier treatment to protect against Giardia, Cryptosporidium, viruses, and Legionella. Systems drawing from surface water face more frequent microbial testing than those relying on deep groundwater, which is better protected from surface contamination by layers of soil and rock.²

Testing frequency depends on system size, source type, and past contamination history. Every laboratory analyzing drinking water samples must hold accreditation from the Environmental Laboratory Accreditation Program (ELAP) within the SWRCB.³ Results from a non-accredited lab are invalid, and the system has to retest at its own expense.

Separate from the routine schedule, EPA uses the Unregulated Contaminant Monitoring Rule to require monitoring for a new list of unregulated contaminants every five years, feeding data on emerging threats into future regulatory decisions.⁴

When a contamination trigger occurs, such as a sudden drop in disinfectant levels or a natural disaster, immediate testing is required. A significant rise in bacterial counts must be reported to the DDW within 24 hours.⁵ Acute contaminants like E. coli or dangerous nitrate levels demand immediate corrective action, which can include boil-water notices or an alternative water supply.

PFAS and Other Emerging Contaminants

Per- and polyfluoroalkyl substances (PFAS) are one of the most active areas of drinking water regulation. California has set its own notification and response levels rather than wait for federal rules to settle. As of late 2025, the notification level for PFOA is 4.0 nanograms per liter, with a response level of 10 nanograms per liter based on a running annual average. When a response level is exceeded, the water system must either take the contaminated source offline or provide public notification within 30 days.⁶

At the federal level, the picture is unsettled. EPA’s 2024 PFAS National Primary Drinking Water Regulation set MCLs for several PFAS compounds, but the rule faces ongoing litigation. In January 2026, the D.C. Circuit denied EPA’s request to vacate standards for four of the regulated PFAS chemicals. EPA announced in May 2025 that it was pushing the compliance deadline for PFOS and PFOA standards back two years to 2031, and it has signaled it will begin rulemaking to rescind and possibly replace the portion of the rule covering a group of mixed PFAS chemicals.⁷ For California systems, the state’s own notification and response levels may end up being the binding constraint regardless of how the federal rule shakes out.

Permits and Certified Operators

Every public water system in California must hold a domestic water supply permit from the state. Under Health and Safety Code Section 116555, the owner of a public water system must ensure the system complies with primary and secondary drinking water standards, is not subject to backflow under normal conditions, and provides a reliable supply of safe drinking water.⁸

The same statute requires public water systems to employ only water treatment and distribution operators certified by the SWRCB at the grade appropriate for the system’s classification. Community water systems and nontransient noncommunity systems must place operations under the direct supervision of a certified operator whose grade equals or exceeds the system’s classification level.⁸ It is the main safeguard against an unqualified person making treatment decisions that affect thousands of customers.

Reporting and the Consumer Confidence Report

Public water systems file annual reports to the DDW through the SWRCB’s Electronic Annual Report (eAR) system, covering source capacity, population served, service connections, financial capacity, and compliance.⁹ Larger systems face more detailed reporting.

For a confirmed detection above an MCL, notification level, or response level, the system has 30 days to comply with public notification and corrective-action requirements.¹⁰ Systems with more than 10,000 service connections that detect contaminants above their public health goals must prepare exceedance reports every three years and hold public hearings on them.¹¹ Significant changes to treatment processes or new sources require engineering reports and state approval before they take effect.

Every community water system must prepare an annual Consumer Confidence Report (CCR) summarizing the quality of water delivered during the previous year. The CCR must be provided to customers, and the system must certify delivery to the DDW. For the 2025 CCR, that certification is due to the DDW district office by October 1, 2026.¹¹ If you want to see what is in your tap water, the CCR is the document to ask for.

How Customers Must Be Notified When Something Goes Wrong

When a primary drinking water standard is violated, a monitoring requirement is missed, or a variance condition is not met, the water system must notify both the DDW and its customers.⁵ The urgency depends on the severity.

For situations with the potential to immediately affect human health (Tier 1), water systems have 24 hours to notify customers through television and radio, posting in public places, personal delivery, or another method approved by the state.¹² California adds a multilingual requirement: written Tier 1 notices must be provided in English, Spanish, and any other language spoken by a non-English-speaking group that exceeds 10 percent of the people served by the system.⁵

For violations that exceed a standard but do not pose an immediate health risk (Tier 2), the system must notify customers as soon as possible but within 30 days, by mail, media, or posting.¹² All notices must identify the contaminant, describe possible health effects, and explain what vulnerable populations should do. The DDW approves the content, and the system must repeat the notice at intervals until the violation is resolved.

Penalties for Violations

Civil penalties under Section 116725 of the Health and Safety Code fall into tiers based on the type of violation:

False statements in compliance documents: up to $5,000 per day per violation.
Violating an order related to primary drinking water standards or failing to provide safe water: up to $25,000 per day per violation.
Violating other orders issued under the Act: up to $5,000 per day per violation.
Operating a public water system without a permit: up to $25,000 per day per violation.

Each civil penalty is separate from and in addition to any other penalty imposed under the Act or any other law.¹³

Criminal penalties under Section 116730 apply to anyone who knowingly falsifies compliance documents, conceals or destroys required records, withholds information about an imminent danger, violates an order presenting imminent danger, or operates without a permit. A first conviction carries a fine of up to $25,000 per day plus up to one year in county jail. For repeat offenders, the stakes rise to state prison (16, 20, or 24 months) and fines between $2,000 and $50,000 per day.¹⁰

Tampering with a public water system is a separate felony carrying three to five years in state prison and a fine of up to $30,000. Even threatening to tamper is a felony punishable by 16 months to three years and up to $20,000 in fines.¹⁴

Beyond fines and criminal charges, the SWRCB can issue compliance orders requiring infrastructure upgrades or operational changes. If a system remains noncompliant, the state can appoint an external administrator to take over operations or revoke the provider’s permit entirely, forcing another entity to step in.

What a Resident or Affected Person Can Do

The federal Safe Drinking Water Act includes a citizen suit provision at 42 U.S.C. § 300j-8 that lets any person file a civil action against a water system violating a federal drinking water requirement, or against EPA for failing to perform a non-discretionary duty. The suit goes to federal district court, and the plaintiff must give 60 days’ written notice to EPA, the alleged violator, and the state before filing. A citizen suit cannot proceed if EPA or the state is already diligently prosecuting the same violation, though any person can intervene in that ongoing case.¹⁵

Outside of that mechanism, individuals harmed by contaminated water can pursue state tort claims against negligent water providers. Class actions have been filed in cases of widespread contamination, and courts can issue injunctions requiring immediate corrective measures. The practical barrier for most individuals is proving that a specific provider’s negligence caused a particular health problem or property damage, which typically requires expert testimony and extensive sampling data.

The Human Right to Water

California codified a human right to water through Assembly Bill 685 in 2012, now at Water Code Section 106.3, declaring that every person has the right to safe, clean, affordable, and accessible water adequate for drinking, cooking, and sanitation. The declaration does not create a private right of action on its own, but it requires state agencies to consider that right when making decisions affecting water policy. The practical outgrowth is the Safe and Affordable Drinking Water Fund, created by Senate Bill 200, which directs state resources toward water systems in disadvantaged communities that cannot meet drinking water standards on their own. For communities stuck with contaminated or unreliable water, these provisions give advocacy groups and local officials a lever to pull when pushing for state funding and intervention. The SWRCB maintains a list of water systems in violation and tracks which communities are most in need of help.

1
Justia Law. California Health and Safety Code Article 1 – Pure and Safe Drinking Water
2
Legal Information Institute. California Code of Regulations Title 22 64650 – General Requirements
3
Legal Information Institute. California Code of Regulations Title 22 64801.00 – Definitions
4
U.S. Environmental Protection Agency. Fifth Unregulated Contaminant Monitoring Rule
5
California Legislative Information. California Health and Safety Code HSC 116450
6
State Water Resources Control Board. PFOA Notification Level Issuance
7
Environmental and Energy Law Program. PFAS in Drinking Water
8
State Water Resources Control Board. California Safe Drinking Water Laws
9
California State Water Resources Control Board. Electronic Annual Report
10
State Water Resources Control Board. California Safe Drinking Water Laws
11
State Water Resources Control Board. Consumer Confidence Reports (CCRs)
12
Environmental Protection Agency. Public Notification Rule
13
California Legislative Information. California Health and Safety Code 116725
14
Justia Law. California Health and Safety Code Article 11 – Crimes and Penalties
15
Office of the Law Revision Counsel. 42 U.S. Code 300j-8 – Citizens Civil Action