Municipal Separate Storm Sewer System (MS4)

Storm Water Permit Renewal 2024

The Santa Ana Water Board is the state entity responsible for water quality in the Santa Ana River Basin. The southern portion of Claremont drains to the Santa Ana River. Parts of the Santa Ana River have high levels of bacteria, posing a risk to recreational users. The Santa Ana Water Board has set safe limits for bacteria in the river and requirements on cities to identify and reduce sources of bacteria to meet the limits. The Santa Ana Water Board issued a permit to regulate bacteria discharged from the cities of Pomona and Claremont. Other cities have a separate permit.

Now, the Santa Ana Water Board is renewing the permits according to state and federal law. The Santa Ana Water Board has created a mailing list exclusively for Pomona's and Claremont's permit to inform interested parties. By signing up, you will receive information on the permit's progress, public workshops, and opportunities to provide feedback. Whether you're a concerned citizen, a local business owner, or an environmental advocate, we welcome your participation in this important effort.

  1. Go to https:// public.govdelivery.com/accounts/CAWRCB/subscriber/new?qsp=santa_ana
  2. Enter your email address
  3. Under the "Stormwater" tab, select "Region 8 - Stormwater - Claremont-Pomona Bacteria TMDL Permit"
  4. Click "Submit"
  5. Enter your first name, last name, and county

Have questions about this notice? You can reach Santa Ana Water Board staff at RB8stormwater.comments@waterboards.ca.gov.

Stormwater Overview

Storm water is defined by US EPA as the runoff generated when precipitation from rain and snowmelt events flows over land or impervious surfaces without percolating into the ground. Stormwater is often considered a nuisance because it mobilizes pollutants such as motor oil and trash. In most cases, stormwater flows directly to water bodies through sewer systems, contributing a major source of pollution to rivers, lakes, and the ocean. Stormwater discharges in California are regulated through National Pollutant Discharge Elimination System (NPDES) permits. However, storm water may also act as a resource and recharge to groundwater when properly managed.

The Federal Clean Water Act (Clean Water Act) prohibits certain discharges of stormwater containing pollutants except in compliance with a National Pollutant Discharge Elimination System (NPDES) permit. The NPDES stormwater program regulates some stormwater discharges from three potential sources: municipal separate storm sewer systems (MS4s), construction activities, and industrial activities.

Municipal Storm Water Program

The Municipal Storm Water Program regulates stormwater discharges from municipal separate storm sewer systems (MS4s) throughout California. U.S. EPA defines an MS4 as a conveyance or system of conveyances (including roads with drainage systems, municipal streets, catch basins, curbs, gutters, ditches, man-made channels, or storm drains) owned or operated by a State.

Pursuant to the Federal Water Pollution Control Act (Clean Water Act) section 402(p), stormwater permits are required for discharges from an MS4 serving a population of 100,000 or more. The Municipal Storm Water Program manages the Phase I Permit Program (serving municipalities over 100,000 people), the Phase II Permit Program (for municipalities less than 100,000), and the Statewide Storm Water Permit for the State of California Department of Transportation. The State Water Resources Control Board (State Water Board) and Regional Water Quality Control Boards (collectively, the Water Boards) implement and enforce the Municipal Storm Water Program.

Stormwater and Water Quality Inspections 

The City of Claremont is required to perform inspections of applicable businesses every two years to comply with the Los Angeles Regional Municipal Stormwater Permit, Order No. R4-2021-0105.

Learn more about the City's Stormwater Inspections 

City of Claremont Stormwater Program Highlights

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