A methane gas leak beneath a Newport Beach home forced emergency evacuations earlier this month, revealing how California’s legacy oil infrastructure continues to endanger modern neighborhoods.
CBS Los Angeles reported that residents on Marcus Avenue heard hissing noises and smelled gas coming from be
neath their home’s foundation. Investigators soon found that an abandoned private oil well, capped nearly a century ago, was venting pressurized methane roughly 800 feet below the surface.
Emergency crews evacuated seven nearby homes and set up a temporary venting system to safely release the buildup of methane and hydrogen sulfide gases. Later that day, city officials cleared most residents to return, though the affected property remains uninhabitable until long-term repairs are complete.
This incident underscores a growing issue across coastal Southern California, where historic oil fields, incomplete well closures, and expanding urban development increasingly overlap. As builders and homeowners renovate in these areas, they face renewed risks from vapor intrusion and methane migration that many assumed were long resolved.
Insights From David McAlister, Principal Geologist at McAlister GeoScience
“We are in an interesting time where legacy infrastructure such as these old oil wells are causing problems for new construction and renovation practices. Until relatively recently (within the past 10–20 years or so), ‘abandonment’ of an oil well simply meant making it so pumps could no longer be put down the well and ensuring people or children wouldn’t fall down the surface completion.
Modern building practices are trending toward energy efficiency and keeping the conditioned or heated air inside the structure. Unfortunately, this means the vapors from incompletely sealed historic oil wells venting into structures are sealed in also. This series of good-intentioned events leads to a big problem of vapors reaching cancer-threat levels or even up to explosive levels.
Many municipalities in the Southern California area have enacted methane testing requirements as part of the building-department permit process for construction, renovation, or grading of properties in certain areas commonly identified as ‘Methane Zones’ — areas where oil-well drilling activities historically were conducted or even oil seeps came up from the subsurface naturally.”
If your property lies in or near a former oil field, don’t wait until vapor intrusion becomes a safety issue. McAlister GeoScience can help you identify old wells, perform methane testing, and develop mitigation strategies tailored to your site. Contact us today to protect your investment and ensure compliance before construction or renovation begins.
References:
Hylton, C. (2025, October 23). Officials in Newport Beach issue evacuation order for several homes after methane gas was detected. CBS Los Angeles. https://www.cbsnews.com/losangeles/news/newport-beach-evacuation-order-methane-gas/