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Site History

Tank Farm Road in San Luis Obispo cuts through the center of a 332-acre former oil storage facility. Union Oil Company of California (Union Oil) built its San Luis Obispo Tank Farm at the beginning of the 20th century when the oil industry was booming and space was needed to store crude oil produced from the San Joaquin Valley and Santa Maria Valley oil fields.

In 1926, lightning sparked a massive five-day fire so intense it created its own weather system. Millions of barrels of oil were either burned or were released below the surface of the property during the fire. The disaster left some residual oil impacts to soil and groundwater that still remain at the site today.

Historical Timeline



Union Oil Company of California (Union Oil) constructed the San Luis Obispo Tank Farm to store oil produced from the San Joaquin Valley and Santa Maria fields. The oil was then transferred to Avila Tank Farm for transport to oil refineries. No refined products were made on site.



On April 7, lightning sparked a massive fire that destroyed six large oil storage reservoirs and 14 of the 19 aboveground steel tanks, releasing or burning an estimated six million barrels of oil. The fire was extinguished on April 11.


Early 1930s

San Luis Obispo Tank Farm was rebuilt and oil operations continued for five more decades.



Oil storage operations at San Luis Obispo Tank Farm ceased.



Most aboveground storage tanks were removed. Pump house and heater building were demolished.



Union Oil conducted a site assessment to determine human health and ecological risks on site.



Chevron Corporation acquired Union Oil Company of California.

2006 low res


Planning for remediation and development commenced.

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Project applications were submitted to San Luis Obispo City and San Luis Obispo County for remediation and development approvals.

2014 low res


San Luis Obispo City Council unanimously approved the San Luis Obispo Tank Farm Environmental Impact Report. San Luis Obispo County unanimously approved the Conditional Use Permit for remediation and restoration.



After obtaining the necessary construction permits from San Luis Obispo County and other agencies, remediation and restoration work began.

present low res


Remediation and restoration work continues.

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