For Immediate Release, October 19, 2021


Liz Jones, Center for Biological Diversity, (310) 612-1018,
Mary A. Ciesinski, ECOSLO Environmental Center of San Luis Obispo, (805) 710-8021,

San Luis Obispo County Approves Disputed Drilling at Arroyo Grande Oilfield

Hearing Comes After Discovery of Covert Drilling Approvals

SAN LUIS OBISPO, Calif.— The San Luis Obispo County Board of Supervisors rejected an appeal from the Center for Biological Diversity and the pleas of concerned community members today in approving dozens of new oil and gas wells at the Arroyo Grande oilfield.

The approval of Sentinel Peak Resources’ request to drill 31 new wells comes after the Center’s discovery that the county has quietly authorized 37 new wells on Sentinel’s expired permit since 2017.

Sentinel should not have drilled any new wells since 2015, when the company’s request to extend its permit was put on hold pending the Center’s appeal. Rejecting that appeal today, the board decided Sentinel can keep drilling with no further review of the harms and threats to groundwater or the climate.

“With this short-sighted decision, the board abandoned its duty to protect residents through oversight and review of drilling operations,” said Liz Jones, an attorney at the Center’s Climate Law Institute. “This decision puts communities and our climate at risk by potentially allowing Sentinel to drill in perpetuity without proper environmental review.”

In a letter to the county in August, the Center detailed its findings that the company is abandoning old wells and drilling new ones that it misleadingly labels “replacements.” In authorizing these wells, the county allowed Sentinel to blow past the limits of its original permit and avoid state environmental review for new wells.

Sixteen environmental, community and public-health groups sent a letter supporting the Center’s appeal, detailing how the county has shut the public out of its decision-making process and ignored the concerns of residents living near the oil field.

The 37 wells authorized at Arroyo Grande since 2017 include many injection wells that use large amounts of energy and water. These wells also increase the risk of spills that threaten people’s health and the environment.

“The dangerous drilling processes used in Arroyo Grande draw from the county’s already low water supplies and the resulting waste pollutes Pismo Creek and nearby groundwater supplies at a rate of over a million gallons a day,” said Mary Ciesinski, executive director of ECOSLO – the Environmental Center of San Luis Obispo.  “The board’s approval of Sentinel Peak’s application threatens our water, air, and climate at a time when we need leaders who will help our community turn away from fossil fuel production and turn toward renewable energy.”

The Center for Biological Diversity is a national, nonprofit conservation organization with more than 1.7 million members and online activists dedicated to the protection of endangered species and wild places.