California Penal Code 370 is the statute that defines what counts as a public nuisance under California criminal law. It covers anything that harms public health, is indecent or offensive to the senses, interferes with the comfortable enjoyment of life or property, or obstructs public spaces like streets, parks, and navigable waterways, so long as the condition affects a whole community, a neighborhood, or a considerable number of people.1California Legislative Information. California Penal Code 370 Section 370 by itself sets no penalty. The punishment comes from Penal Code 372 and 373a, which make maintaining a public nuisance a misdemeanor carrying up to six months in county jail, a fine of up to $1,000, or both.
What Qualifies as a Public Nuisance
Section 370 is a definitional statute. It draws the line between ordinary annoyances and conduct serious enough to be treated as a criminal public nuisance. Under the statute, a public nuisance is anything harmful to health, indecent, offensive to the senses, or an obstruction to the free use of property that interferes with the comfortable enjoyment of life or property. It also reaches anything that unlawfully blocks the normal use of navigable waters, public parks, squares, streets, or highways.1California Legislative Information. California Penal Code 370
In practice, that language covers a wide range of conditions: persistent foul odors from a property, loud machinery running at all hours, illegal dumping that creates health hazards, smoke or chemical emissions drifting into a residential area, or physical obstructions blocking a public road or sidewalk.
The operative phrase is “comfortable enjoyment of life or property.” Courts use it to measure whether a condition has crossed from merely annoying to legally actionable. A barking dog that bothers one neighbor for an afternoon almost certainly does not qualify. A commercial operation generating toxic fumes that sicken an entire block for weeks almost certainly does.
How Many People Must Be Affected
A nuisance only qualifies as “public” if it reaches beyond a handful of individuals. Section 370 requires that the condition affect an entire community, a neighborhood, or a considerable number of people.1California Legislative Information. California Penal Code 370 A dispute between two neighbors over a tree, a fence, or a single party typically falls into private nuisance territory and is handled through civil remedies rather than a criminal charge.
California Civil Code 3480 adds a useful clarification: a nuisance is still public even if the harm is not felt equally by everyone affected.2Justia Law. California Civil Code 3480 Residents immediately next to a contaminated site may develop serious health problems while people a few blocks away only notice an odor. The condition is still a public nuisance because it radiates from a single source across the area. What matters is the breadth of the affected population, not whether everyone suffers to the same degree.
Penalties Under Sections 372 and 373a
Section 370 defines the offense. Section 372 supplies the punishment: anyone who maintains or commits a public nuisance, or who willfully fails to perform a legal duty to remove one, is guilty of a misdemeanor.3California Legislative Information. California Penal Code 372 Because Section 372 does not set its own specific punishment, the default misdemeanor penalties in Penal Code 19 apply: up to six months in county jail, a fine of up to $1,000, or both.4California Legislative Information. California Penal Code 19
A conviction also produces a misdemeanor record, which can show up in employment, housing, and professional licensing background checks. For many defendants, that lasting record is a heavier consequence than the fine or the jail exposure.
Each Day Can Be a Separate Offense
Penal Code 373a is where exposure can escalate quickly. Once a property owner or occupant receives written notice from a health officer, district attorney, city attorney, or city prosecutor to remove or abate the nuisance, every day the nuisance continues is a separate misdemeanor offense.5California Legislative Information. California Penal Code 373a A property owner who ignores a notice for 30 days could, in theory, face 30 separate counts, each carrying its own potential jail time and fine.
Section 373a also imposes a duty on prosecutors. The district attorney or city attorney is required to continuously prosecute anyone violating the section until the nuisance is fully removed.5California Legislative Information. California Penal Code 373a Delay does not make the problem recede; it compounds it.
Who Can Be Charged
Section 373a reaches beyond property owners. It applies to anyone who maintains, permits, or allows a public nuisance on property they own, and also to anyone occupying or leasing another person’s property who lets a nuisance persist there.5California Legislative Information. California Penal Code 373a Tenants and landlords can both face charges if either allows the condition to continue after notice.
Common Defenses
Not every unpleasant condition supports a valid public nuisance charge. A few defenses come up repeatedly:
- Isolated incident. A public nuisance typically involves an ongoing or recurring condition. A single one-time event, like a loud one-night gathering, usually does not meet the threshold. Prosecutors need to show the condition is persistent or has a lasting effect.
- Too few people affected. If the alleged nuisance only bothered a couple of individuals rather than a neighborhood, it does not satisfy the “considerable number of persons” requirement in Section 370. The complaint may support a private nuisance claim, but not a criminal charge.
- No written notice. A charge under Section 373a requires reasonable written notice from a health officer, prosecutor, or city attorney. Without proof that notice was properly served, the daily-offense provision cannot apply.
- Compliance with regulations. Operating within applicable permits and zoning rules can weigh against a finding that an activity is a nuisance, though compliance is not an automatic shield.
If You Receive an Abatement Notice
Most public nuisance cases begin with a complaint to a local code enforcement office, health department, or city attorney. The agency investigates and, if it confirms a nuisance, serves the owner or occupant with written notice specifying the problem and the required corrective action. That notice is the trigger for Section 373a’s daily-offense rule, so the clock starts the day it is served.
Comply, and the matter typically ends. Ignore the notice, and the government has several escalating options. It can file criminal charges under Sections 372 and 373a. It can file a civil action in the name of the people of California under Code of Civil Procedure 731 to obtain an injunction ordering the nuisance stopped, with contempt penalties if the order is defied.6California Legislative Information. California Code of Civil Procedure 731 Civil Code 3491 confirms that criminal prosecution, civil action, and direct abatement are all available remedies for a public nuisance.7California Legislative Information. California Civil Code 3491 For hazardous conditions, the government can move faster and sometimes arrange for contractors to clean up the property directly, then recover the cost through a lien.
Waiting to see whether the government will follow through is the most expensive mistake people make in these situations. The daily-offense rule turns delay into additional misdemeanor counts, and cleanup costs billed to the owner typically run higher than voluntary compliance would have cost. If you have been served, treat the deadline in the notice as real and get legal advice before it expires.