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Hayward Fault · BMC 19.34.040
Seismic Gas Shut-Off Valves in Berkeley, CA
The Hayward Fault runs right through Berkeley, and broken gas lines are one of the main fire risks after a big quake. Berkeley’s code requires a motion-activated shut-off valve on new buildings and whenever you pull a plumbing or mechanical permit. Here’s what that means for your house.
Last reviewed October 15, 2026
Quick answer: Berkeley requires a listed, motion-activated seismic gas shut-off valve in all new construction with gas piping, and on existing buildings when an addition, alteration or repair gets a plumbing or mechanical permit (BMC 19.34.040). Excess-flow valves don’t count as a substitute. The valve goes on your side of the PG&E meter and closes in a quake stronger than magnitude 5.0.
When Berkeley requires a valve
| Situation | Requirement |
|---|---|
| New building with gas piping | Motion-activated seismic valve required |
| Existing building, one gas meter, permitted addition, alteration or repair | Valve required when a plumbing or mechanical permit is issued |
| Existing building, several meters, permitted work on one unit | Valves on that unit’s meter and the common-area meter |
| Valve installed before the rule, still working | Can stay if kept operational |
In practice, that means a permitted gas water heater replacement, furnace swap, repipe or remodel is the moment the valve comes into play. If you’re planning any of those, include it in the estimate. See water heater replacement.
Motion-activated vs excess-flow valves
| Motion-activated (seismic) | Excess-flow | |
|---|---|---|
| Closes when | The building shakes beyond its set point (above M5.0 under Berkeley’s code) | Gas flow suddenly exceeds a set rate, as with a severed line |
| Berkeley code | Required type | Not accepted as a substitute |
| Where it goes | Owner’s side of the PG&E meter, rigidly mounted | Usually at the meter or an appliance |
| After it trips | Owner resets it per the manufacturer once it’s safe; relight pilots | Resets when flow conditions return to normal, depending on the model |
Code requirements beyond the type: the valve must be tested and listed by a recognized agency such as IAPMO, UL or IAS, be resettable by the owner, and be installed per the manufacturer’s instructions.
Why it matters here
The Hayward Fault has an estimated 33% chance of a magnitude 6.7 or larger earthquake by 2043, the highest of any Bay Area fault, according to USGS figures (via Temblor). Its last major rupture was on October 21, 1868, and UC Berkeley’s Memorial Stadium sits right on top of it (Berkeley News).
After a strong quake, a valve that has already closed means one less thing to find in the dark. It also protects the house while you’re away.
After a quake: what to do
- Smell gas or hear hissing? Leave the house and call 911 or PG&E at 1-800-743-5000 from outside.
- No sign of a leak? Check appliance connections and the water heater for damage.
- Reset only when it’s safe. Follow the valve maker’s reset steps.
- Relight pilots. Water heater, furnace and any other pilot appliances. PG&E can help if you’re unsure.
Other quake-ready plumbing steps
- Strap the water heater to the City’s bracing standard
- Use code-compliant flexible connectors on gas appliances
- Know where your main water and gas shutoffs are, and keep the right wrench by the gas meter
FAQ
Common Questions
Is an earthquake gas shut-off valve required in Berkeley?
It’s required in all new buildings with gas piping, and in existing buildings whenever an addition, alteration or repair gets a plumbing or mechanical permit. That includes many water heater replacements, repipes and remodels. Berkeley’s code accepts motion-activated valves only, not excess-flow valves.
Is an excess-flow valve enough in Berkeley?
No. Berkeley Municipal Code 19.34.040 says excess-flow valves can’t be installed as a substitute for a motion-activated seismic gas shut-off valve. An excess-flow valve reacts to a sudden surge in gas flow; a seismic valve reacts to shaking.
Where does the valve go?
On your side of the PG&E meter, downstream of the service tee, rigidly mounted to the building unless the manufacturer says otherwise. In buildings with several meters, permitted work on a unit means valves on that unit’s meter and the common-area meter.
Do I need a valve to sell my house?
Berkeley’s gas valve code section doesn’t list sale as a trigger; the triggers are new construction and permitted work. Sales have other requirements, such as the sewer lateral certificate and water heater bracing. Check the current rules with your agent before listing.
What happens after the valve trips?
Gas to the house stops. If you smell gas or see damage, leave and call 911 or PG&E at 1-800-743-5000 from outside. If there’s no sign of a leak, the valve can be reset following the manufacturer’s steps, and then every pilot light has to be relit.
What magnitude sets it off?
Berkeley’s code calls for valves that activate in a seismic event greater than magnitude 5.0. They have to be listed by a recognized testing agency and resettable by the owner.
Keep reading
Related Services
Water heaters
A permitted gas water heater swap triggers the valve requirement.
Emergency plumber
What to do if a quake or anything else breaks a line.
Gas line repair
Gas leak repairs, appliance hookups and testing.
Add a seismic valve to your next project
Call (510) 822-3070. The valve, permit and inspection are quoted in writing, alongside any other gas work.
Sources checked October 15, 2026: BMC 19.34.040 – Gas shut-off valves · Temblor – Hayward Fault odds · Berkeley News – Hayward Fault · City of Berkeley – Water heater bracing
Prices on this page are ranges reported by Bay Area homeowners or published by the City, not quotes. Your price comes in writing after the job is seen. Berkeley Plumbing Services connects callers with independent, licensed plumbing contractors; you can check any California contractor’s license at cslb.ca.gov.