Legislative Mandated Reports - 2024
2024 Water Code Section 13385(o) Enforcement Report
Introduction
This report meets the requirements of Section 13385(o) of the California Water Code by sharing ongoing updates on how the Clean Water Act is enforced in California. It summarizes violations of waste discharge permits from the past year, highlights the compliance and enforcement actions taken in response; and assesses how effective current enforcement policies are, including the use of mandatory minimum penalties.
California Water Code Section 13385(o)
The state board shall continuously report and update information on its Internet Web site. The state board shall report annually on or before December 31 regarding its enforcement activities. The information shall include all of the following:
- A compilation of the number of violations of waste discharge requirements in the previous calendar year, including stormwater enforcement violations.
- A record of the formal and informal compliance and enforcement actions taken for each violation, including stormwater enforcement actions.
- An analysis of the effectiveness of current enforcement policies, including mandatory minimum penalties.
The Water Boards use two main databases to track water quality information. The California Integrated Water Quality System (CIWQS) manages permits, inspections, violations, and enforcement activities, while the Storm Water Multiple Application and Report Tracking System (SMARTS) does the same for the Storm Water Program. Together, these systems provide the data used in the Section 13385(o) report.
Most of the report’s tables are available online through the State Water Board’s website. These public reports are updated daily and give users the ability to sort and filter violation and enforcement data from regulated dischargers to find the information most relevant to them.
Facilities
Wastewater facilities covered in this report are those permitted to discharge pollutants into surface waters. These include sewage treatment plants, food processors, oil refineries, power plants, pulp and paper mills, mines, and fish hatcheries. All are regulated under National Pollutant Discharge Elimination System (NPDES) permits. Stormwater facilities in California are also regulated through NPDES permits and fall into three categories: construction, industrial, and municipal.
NPDES facilities and number of inspections
Tip! The links above display information for the current fiscal year. To view past years, use the Fiscal Year dropdown menu. Additional dropdown options are available to help you customize and refine your queries.
The total number of NPDES facilities decreased slightly (<1%) from fiscal year (FY) 23/24 to FY 24/25. Both inspections conducted and total facilities inspected declined by 10%, with wastewater facility inspections decreasing by 13%.
From FY 23/24 to FY 24/25, construction stormwater inspections decreased by 10% and industrial stormwater inspections decreased by 19%, while municipal stormwater inspections increased by 15%.
Violations
This section summarizes the violations for the NPDES Wastewater and Stormwater Programs.
Recorded violations at wastewater facilities decreased by 16.7% between calendar years 2023 and 2024. Currently, 263 wastewater facilities report more than 25 violations. Stormwater facilities experienced a 50% reduction in recorded violations during the same period.
Enforcement
This section outlines compliance and enforcement actions. The Water Boards use a progressive approach, starting with informal measures such as phone calls or staff letters and escalating to formal statutory actions if necessary. Persistent violations may lead to increasingly serious enforcement until compliance is achieved.
Enforcement under the NPDES program is higher than other water quality programs due to mandatory minimum penalties for certain violations. In FY 24/25, the Wastewater Program issued 113 penalty actions, up from 90 the prior year. The Wastewater Program also issued 173 informal actions. This represents a 17% overall increase in enforcement compared to FY 22/23, the highest among Water Board programs.
FY 24/25, the Stormwater Program issued 2,855 enforcement actions. Of these, 2,238 were formal compliance actions for reporting violations, consistent with the Notice of Noncompliance requirement under the Storm Water Enforcement Act, a 58% increase from FY 23/24. The Program also issued 533 informal actions to address other violations like those observed during inspections, such as non-compliance with Best Management Practices. This represents a 67% decrease from the prior year. Additionally, 84 penalty actions were issued, a 60% decrease from FY 23/24.
The number of wastewater facilities with violations but without corresponding enforcement actions decreased by 17% between 2023 and 2024. This change marks a significant, positive reversal in compliance trends.
The Stormwater Program is highly effective in responding to non-compliance: 96% of all violations receive an enforcement response in 2024. The program utilizes formal actions for reporting violations and also uses informal actions as appropriate.
Mandatory Minimum Penalties
This section analyzes the effectiveness of Mandatory Minimum Penalties (MMPs). California law (Water Code sections 13385(h), (i), and 13385.1) mandates MMPs for specific NPDES permit violations. Serious violations (significant effluent limit exceedances or failing to submit monitoring reports for more than 30 days) require a $3,000 penalty per violation. Non-serious violations also require a $3,000 penalty if four or more effluent limit exceedances occur within a six-month period.
The link above compiles Mandatory Minimum Penalty (MMP) violations and enforcement actions since 2010. MMPs for effluent limit violations began in 20000 and for late reports began in 2004. A 2006 statutory change expanded coverage to facilities under general NPDES permits. Since 2010, violations subject to MMPs have declined by about 37%. There were 54 MMPs for reporting violations in 2024 (up slightly from 26 in 2023). As of December 15, 2025, there were 1,428 violations subject to MMPs in 2024, down from 1,666 in 2023. Of these, 47% have received some enforcement and 22% have been fully resolved. In 2024, two facilities had 50 or more violations: Six Flags Magic Mountain in Valencia (72 outstanding) and California Men’s Colony WWTP in the Central Coast region (71 under enforcement).
Additional Resources
Tip! Links to the Annual Performance Measure in this report show limited data. For a broader inquiry, use the link to the Public Report and Data.
NOTE: This report was prepared with AI-assistance to ensure it is clear, professional, and accessible to the public. All data analysis was conducted by Water Board staff.
