Milpitas, CA Environmental Rules: Stormwater Management (2026)
Key Facts
- Governing chapter
- Milpitas Municipal Code Ch. XI-16
- Administering official
- City Manager (MS4 permit)
- Civil penalty
- Up to $25,000 per day per violation
- Emergency reporting
- Call 911 immediately
- Written follow-up report
- Within 5 days of discharge
- SWPPP trigger
- 3+ Stop Work/Noncompliance Notices
Summary
In the City of Milpitas, it is unlawful to discharge nonstormwater or contaminated stormwater into any City storm drain or watercourse under Chapter XI-16, which lists prohibited pollutants and requires Low Impact Development measures for regulated development projects. The City Manager administers the program under the City's MS4 permit.
It shall be unlawful to discharge nonstormwater or contaminated stormwater into any City storm drain or watercourse. Prohibited discharges include, but are not limited to refuse, solid waste, sewage, commercial and industrial wastes, petroleum products, chemicals, soaps and detergents, solvents, paints, contaminated or chlorinated water from pools, spas and fountains (including those treated with copper-based chemicals), swimming pool water, pesticides, herbicides, fertilizers, weeds, dirt, vegetables, grease, animal wastes, turbid fluids, and wastewater generated from the installation, cleaning, treating and washing of copper architectural features, unless permitted in Section XI-16-8.
Full Breakdown
Milpitas Municipal Code Chapter XI-16, Stormwater and Urban Runoff Pollution Control, implements the City's National Pollutant Discharge Elimination System (NPDES) municipal separate storm sewer system (MS4) permit issued by the California Regional Water Quality Control Board, San Francisco Region, and applies to all water entering the City's storm drain system from developed or undeveloped land (section XI-16-1). Section XI-16-5 bars discharging nonstormwater or contaminated stormwater into any City storm drain or watercourse, naming refuse, sewage, industrial waste, petroleum products, chemicals, solvents, paints, chlorinated pool and spa water, pesticides, herbicides, fertilizers, grease, animal waste and copper-cleaning wastewater as prohibited, unless exempted under section XI-16-8.
Exempt discharges include riparian and natural spring flows, uncontaminated groundwater infiltration, and NPDES-permitted discharges, while the City may conditionally exempt items like uncontaminated pumped groundwater under 10,000 gallons per day, air conditioning condensate, individual residential car washing, and irrigation water. Regulated development and redevelopment projects must design and construct Low Impact Development source control, site design and stormwater treatment measures for the life of the project, and no final building or occupancy permit issues without the City Manager's written certification that these requirements are satisfied (section XI-16-6).
Property owners with permanent stormwater treatment measures must record a maintenance obligation against the property and disclose it to any buyer (section XI-16-7). The City Manager or a designee may enter industrial and commercial properties to inspect site controls and required Best Management Practices for outdoor storage, wash areas and drainage (section XI-16-13).
Violations & Fines
Violations of Chapter XI-16 carry criminal penalties under section I-1-4.09-1 and separate civil liability of up to $25,000.00 per day for each day of intentional or negligent violation (section XI-16-14(a)-(b)). The City may issue administrative citations under sections I-21-1.01 through I-21-1.14, a Notice of Noncompliance or Stop Work Notice, and may suspend water, sewer or storm drain access without prior notice if a discharge presents imminent danger to the environment or public health (section XI-16-14(d)-(e)). A construction site with three or more Stop Work Notices or Notices of Noncompliance must hire a Qualified SWPPP Developer or Practitioner within three business days (section XI-16-14(f)), and any violation is also declared a public nuisance abatable under Title V, Chapter 500 (section XI-16-9).
Frequently Asked Questions
Can I hose pool water into the street in Milpitas?
What must I do if I accidentally spill something into a Milpitas storm drain?
How much can Milpitas fine a business for illegal stormwater discharge?
Do new developments in Milpitas need special stormwater design features?
Sources & Official References
Other rules in Milpitas
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