Seismic Gas Shutoff: Altadena vs El Monte
How do seismic gas shutoff rules compare between Altadena, CA and El Monte, CA?
Altadena and El Monte have similar restriction levels.
Altadena, CA
Los Angeles County
LA County Code Title 30 (Residential Code) and Title 28 (Plumbing) require an automatic seismic gas shutoff valve on any new or substantially remodeled residence with natural gas service. Existing homes have no retrofit mandate.
View full Altadena rules →El Monte, CA
Los Angeles County
El Monte enforces California Health and Safety Code Section 19180-19204 and California Plumbing Code Section 1210.18 (as adopted by EMMC Title 15), which require automatic seismic gas shutoff valves on new construction and on certain alterations exceeding $10,000 or 10% of property value.
View full El Monte rules →Key Facts Comparison
| Fact | Altadena | El Monte |
|---|---|---|
| Code Section | LA County Code Title 30 R301.1.4 | - |
| New Construction | Required | - |
| Remodel Trigger | >$10,000 | - |
| Existing Homes | No retrofit mandate | - |
| Code Reference | - | CPC §1210.18 / H&S Code §19180 |
| Trigger for Existing Buildings | - | Alteration > $10,000 OR > 10% of value |
| Required for New Construction | - | Yes |
| Valve Standard | - | CSA-listed, Title 24 certified |
Highlighted rows indicate differences between cities.
Altadena FAQ
Do I need an earthquake gas shutoff valve in Altadena?
Only if you build new or do a remodel over $10,000 that triggers a plumbing permit — LA County Code Title 30.
El Monte FAQ
Do I need an earthquake gas valve in my El Monte home?
Required for new construction and for major remodels exceeding $10,000 or 10% of property value. Existing homes are not retroactively required but valves are strongly recommended.
Where does the seismic gas valve get installed?
Downstream of the gas meter on the building side, accessible for inspection. Must be installed by a licensed plumber and inspected per EMMC Title 15.
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