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Ontario, CA Environmental Rules: Stormwater Management (2026)

Significant Restrictions
Compiled from the official code textEditor Martyn O'NeillLast verified September 2026

Key Facts

Enforcing office
City Engineer
Admin. penalty ceiling
$5,000 per violation per day
Civil penalty range
$3,000 to $25,000 per day
Misdemeanor fine
$3,000 minimum, up to 6 months jail
Private drain inspection
Annually, before rainy season

Summary

Ontario bans dumping refuse, wash water, pet waste, pool chemicals and dozens of other pollutants into any street, gutter or storm drain that feeds the City's stormwater system. The City Engineer enforces the ban with administrative complaints, civil penalties up to $25,000 per day and misdemeanor prosecution.

It is prohibited to: (a) Discharge non-stormwater directly or indirectly to the City's stormwater drainage system, or any street, lined or unlined drainage channel which leads to the City's storm drain or directly or indirectly into any waters of the State unless such discharge is authorized by either a separate NPDES permit or as otherwise specified in § 6-6.207 of this chapter... (c) Throw, deposit, leave, maintain, keep, or permit to be thrown, deposited, placed, left or maintained, any refuse, garbage, sediment or other discarded or abandoned objects, articles, and accumulations, in or upon any street, alley sidewalk, storm drain, inlet, catch basin, conduit or other drainage structures, business place, or upon any public or private lot of land in the City, so that the same may be and/or may become a pollutant.

View official code

Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: 2026 S-32: Current through Ordinance 3338, passed 7-21-2026).

Full Breakdown

Ontario Municipal Code Sec. 206 prohibits discharging non-stormwater into the City's stormwater drainage system, any street or drainage channel, or waters of the State unless a NPDES permit authorizes it, and separately bans throwing or leaving refuse, garbage, sediment or discarded objects on any street, storm drain, catch basin, or public or private lot so that it becomes a pollutant. Sec. 301 adds a residential list barring animal waste, grass clippings, pesticides, concrete and paint cleanup water, motor oil and other vehicle fluids, swimming pool drainage containing chlorine, and household water-treatment brine from reaching any gutter, storm drain inlet or catch basin.

Sec. 302 makes the property owner responsible for abatement and cleanup costs when a tenant's or contractor's illegal discharge originates from the parcel and the responsible party cannot be located. Sec. 303 requires private residential storm drainage inlets, underdrains and gutters to be inspected annually and cleaned before the rainy season once sediment fills 25 percent or more of storage volume, evidence of illegal discharge appears, or hydraulic function is impaired, and private streets must be swept to keep sediment and litter out of the City system.

Enforcement runs through the City Engineer, who under Sec. 605 can issue an administrative complaint with a hearing held within 60 days, appealable to the City Council within 30 days.

Violations & Fines

Administrative civil penalties under Sec. 6-6.605 run up to $3,000 per day for missing a compliance order and up to $5,000 per day per discharge violation, becoming a property lien if unpaid after 60 days. Sec. 6-6.702 sets civil penalties of $3,000 to $25,000 per violation per day, and Sec. 6-6.703 makes willful or negligent violations a misdemeanor punishable by a fine of at least $3,000 and up to six months in jail, with each day of continuing violation a separate offense.

Frequently Asked Questions

What can't I put into an Ontario storm drain?
Sec. 6-6.206 and 6-6.301 ban refuse, sediment, wash water, motor oil and vehicle fluids, pet and yard waste, pool backwash with chlorine, and any material that could become a pollutant in the street, gutter, catch basin or storm drain, unless a NPDES permit authorizes the discharge.
Who enforces Ontario's stormwater discharge ban?
The City Engineer enforces the chapter, issuing an administrative complaint and holding a hearing within 60 days of service under Sec. 6-6.605. A person dissatisfied with the Engineer's decision can appeal to the City Council within 30 days.
What are the penalties for an illegal discharge in Ontario?
Administrative civil penalties reach $5,000 per violation per day under Sec. 6-6.605, civil penalties in court run $3,000 to $25,000 per day under Sec. 6-6.702, and willful or negligent violations are a misdemeanor carrying at least $3,000 and up to six months in jail under Sec. 6-6.703.
Am I liable if my tenant or contractor causes the discharge?
Yes. Sec. 6-6.302 makes the property owner responsible for abatement and cleanup costs when a tenant's or a hired contractor's illegal discharge originates from the parcel and the City cannot locate the responsible party.

Sources & Official References

Other rules in Ontario

All Ontario rules

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