Storm Water Pollution / NPDES

No Dumping sign Opens in new windowIn order to prevent flooding, it is customary for urban areas to have numerous storm drains. The City of Monterey Park has approximately 735 catch basins or point of entries into the system. These storm drains channel water and other materials directly to the ocean.

National Pollutant Discharge Elimination System (NPDES)

Back in 1997, to support the federal law (National Pollutant Discharge Elimination System or NPDES), the City of Monterey Park passed a Storm Water Control Ordinance. The goal of the ordinance is to protect rivers and oceans from pollutants that are dumped or washed into storm drains. 

Under the city's ordinance (MPMC 6.30) which was updated in September 2000, it is illegal for persons to release chemicals, hazardous materials, used motor oil, machinery oils, household cleaners, pesticides, grease, leaves and debris into the streets, gutters or storm drains. Please note however that practices such as car washing, sidewalk washing, and discharges from dechlorinated swimming pools and fountains are allowed. Industrial and commercial businesses, as well as construction contractors are required to modify their operations to eliminate illegal discharge into the storm drains. 

Stormwater and Urban Runoff Pollution and the Safe, Clean Water Program

What is stormwater pollution and urban runoff?

Urban runoff is any water flowing on urban surfaces. This includes flows from storms, as well as flows in dry weather from sources such as over-irrigation and car washing. When urban runoff flows over paved areas like streets, parking lots, and roofs, it collects and carries pollutants on the ground such as litter, pet waste, pesticides, fertilizers, and motor oil. This "toxic soup" is called urban runoff pollution, and when it is caused by rain, we call it stormwater pollution.

Stormwater pollution flows through underground storm drain pipes and flood control channels into our local waterways and the ocean. In Monterey Park our local waterways are the San Gabriel River and five of its tributaries: Walnut Creek, San Jose Creek, Puente Creek, San Jose Creek, and Big Dalton Wash. The San Gabriel flows to the ocean at the San Pedro Bay, between Long Beach and Seal Beach. To protect our waterways, we must prevent and control stormwater pollution.

What are the effects of stormwater pollution?

Stormwater pollution poses a health threat to aquatic life, as well as to people who recreate in waterways and the ocean. Common stormwater pollutants include bacteria, toxic chemicals, and trash. After a rain event, high levels of bacteria in waterways and the ocean can make people sick and result in beach closures. This impacts swimming, beach tourism, fishing, and boating. Some pollutants such as pesticides and heavy metals can be toxic to marine life. Plastic trash may also degrade and accumulate toxic chemicals.  Aquatic life ingest these toxic chemicals and pass them along the food chain. This can result in the contamination of locally caught seafood, making it unsafe for consumption. Trash can also suffocate, entangle, and starve aquatic life.

How do we protect our waterways from stormwater pollution?

Follow the steps below:

  1. Do not dump waste or discharge wastewater into the storm drain system. It is a violation of state regulation and Monterey Park Municipal Code Chapter 6.30.030. Outside of pure stormwater, most discharges to the storm drains are wastewater. The exceptions include natural flows, emergency firefighting flows, and a few “conditionally” allowed discharges such as pool dewatering and residential vehicle washing. The following is the full list of conditionally allowed discharges, along with the conditions to meet: Conditionally allowed discharges to the storm drains
  2. Report spills and illicit discharges of wastewater.  To report a spill or an illicit discharge of wastewater, please contact the Los Angeles County 24-Hour Water Pollution Reporting Hotline at 1-888-CLEAN-LA (1-888-253-2652). For emergencies call 911.
  3. Follow practices to prevent or control pollution during storm events. The practice to follow depends on the source of pollution. The following are practices for residents, students, land developers, and businesses:
Follow the best pollution prevention practices illustrated in this flyer and listed below. Ensure that any companies providing services for you are following these practices as well. In addition, consider participating in a local cleanup event, such as California’s annual coastal cleanup day which is held in September.
School Children
School children can learn more through programs offered by the Los Angeles County Department of Public Works. The "Environmental Defenders" is an assembly program for local elementary schools that educates students in stormwater pollution prevention. To schedule an assembly at your school, submit an Assembly Scheduling Form, or call (310) 551-5375. The "Generation Earth" program works alongside middle and high school educators to help students explore environmental topics that include stormwater pollution prevention.
Construction and Land Use Development
  • During land disturbance activities, control erosion and prevent sediment and construction wastes from discharging to the street or storm drains.
  • Projects that require a soil disturbance permit with the City must implement at a minimum the stormwater Best Management Practices (BMPs) in Tables 7 and/or 8 of the State’s Regional Municipal NPDES Permit (where applicable). The purpose of the BMPs is to prevent erosion and sediment loss, and the discharge of construction wastes. This flyer illustrates many of these BMPs at a small construction site.
  • Sites that disturb an acre of land or more must apply for and comply with the State General NPDES Permit for Construction Activities.

Also note that certain land development projects will require the construction or installation of permanent stormwater capture and treatment systems.

Industrial Businesses (including manufacturing, production, transportation, and storage)

Commercial Businesses

Protect raw and waste material from exposure to precipitation. See the following fliers for sector-specific pollution prevention practices: Food Service, Auto Service, and General Business (English, Spanish).

Should you need assistance complying with the City’s stormwater pollution prevention program, please contact the Public Works Department at (626) 307-1320. 

What does the City do to protect our waterways from stormwater pollution?

The City runs a number of stormwater pollution prevention programs. This includes:

  • Removing pollutants through services such as street sweeping, storm drain cleaning, and litter pick-up
  • Leading or partnering in the construction of projects that capture and treat polluted urban runoff
  • Installing trash capture screens over public storm drain inlets
  • Ensuring certain land development projects capture or treat polluted stormwater
  • Ensuring businesses and construction sites implement pollution prevention practices
  • Investigating and resolving complaints of polluted discharges
  • Educating the public in pollution prevention and encouraging their participation
  • Cooperating and sharing costs with neighboring agencies for water quality monitoring, compliance reporting, and project planning

To see the implementation status of both regional and local stormwater pollution prevention projects and programs, visit Upper Los Angeles River Watershed (ULAR) website. The City pays for these projects and programs through a combination of fees, the City’s General Fund, and the Safe Clean Water Program (Measure W).

The Safe, Clean Water Program

The Safe, Clean Water (SCW) Program–also known as Measure W–provides local, dedicated funding to increase our local water supply, improve water quality, and protect public health. The funding comes from a special parcel tax of 2.5 cents per square foot of impermeable surface area on properties within the LA County Flood Control District (District). The Program is divided into a District Program, a Regional Program, and a Municipal Program.

If you are curious how the money is being spent, visit the District’s website at To see how the City is spending its SCW Municipal Program funds, view the City’s Annual Plans and Reports at the website’s Municipalities page. The City uses these funds in part to implement its Stormwater Pollution Prevention Program.

The City has flexibility on the types of projects and programs it funds under the SCW Municipal Program.


Please report sewer and/or storm water back-ups to the city as soon as possible. Call Department of Public Works at 626-307-1320 or submit a request through GoMPK.