Senate panel advances AB 527 to speed exploratory geothermal development, environmental groups urge tighter limits

Assemblymember Pappan’s AB 527, which would create a narrow California Environmental Quality Act (CEQA) exemption for exploratory geothermal wells that meet specified conditions, was advanced by the Senate Natural Resources and Water Committee as amended and referred to the Appropriations Committee.

The bill’s author and backers said the exemption would allow developers to drill temporary, low‑impact exploratory wells without undergoing a full CEQA review twice — once for exploration and again for project development — while opponents said the change risks environmental harm because new enhanced geothermal techniques resemble hydraulic stimulation and need full review.

AB 527 would exempt exploratory geothermal wells from separate CEQA review if they meet environmental sideboards adopted in the bill, including prohibitions on siting in wetlands or designated conservation lands, requirements for tribal and historic resource protections, and full site reclamation. The author told the committee the exemption is limited to exploration, not full project build out, and said it is intended to reduce regulatory delay that drives geothermal projects out of state.

Supporters included Myles Horton of Sonoma Clean Power, who said geothermal can provide “clean base‑load power” for times when there is “no sun, no wind” and argued that the duplicative CEQA process deters developers and raises costs. Labor witnesses, including representatives of operating engineers and building trades, told the committee geothermal projects could produce stable local jobs in rural counties such as Sonoma and Mendocino.

Opponents, including Kim Delfino of Earth Advocacy (on behalf of Defenders of Wildlife and others) and Matthew Baker of the Planning & Conservation League, said that although they support geothermal generally, the bill as drafted allowed too large a disturbance footprint and insufficient safeguards for water resources and chemical disclosure. They highlighted committee amendments that capped disturbance at 20 acres with no more than 12 acres of new ground disturbance but urged a smaller cap (they cited an average five‑acre exploration footprint) and stronger limits on temporary roads, electrical crossings, and use of stimulation techniques until environmental and public‑health risks are better understood.

Supporters pointed to a federal precedent, noting that the Bureau of Land Management and NEPA processes have treated exploratory geothermal wells differently and that, over several decades, exploratory wells have typically produced negative CEQA/NEPA findings when studied. Witnesses for industry and clean‑power purchasers described enhanced geothermal techniques as different from oil/gas hydraulic fracturing: proponents said the systems are designed as closed loops, with injection and production occurring in steel‑lined wells far below aquifers; opponents said that removing CEQA review in advance of demonstration of safe deployment raises the risk of leaks, contamination, or other harms and reduces transparency.

Committee members expressed the tension between speeding development of a reliable renewable resource and protecting water, habitat and cultural resources. Vice Chair Ciarto said California risks losing projects to other states if the permitting process is duplicative and slow, while Senator Laird pressed for assurances that water and wastewater risks are covered and noted concern that removing CEQA review reduces a check on whether designs are “properly designed.” The author and witnesses pointed to recently adopted amendments requiring pre‑surveying and directing CalGEM and other agencies to promulgate updated regulations and to public disclosure of stimulation fluid contents.

After discussion the committee took the bill under submission for a motion and later recorded a committee vote advancing AB 527 as amended to the Appropriations Committee (final committee vote recorded in the transcript as 7‑0). The committee record shows continuing engagement between the author, environmental organizations and industry on technical and disclosure questions.

Why it matters: California and local community stakeholders are weighing how to accelerate new clean‑energy technologies without foregoing environmental review that can surface risks to water, habitat and tribal cultural resources. Proponents argue AB 527 reduces delays that push geothermal investment out of state, while opponents say the proposed CEQA exemption is premature for newer stimulation techniques and should be narrowed further or tied to stronger enforceable safeguards.

Votes at hearing and next steps: The committee voted to advance AB 527 as amended to Appropriations. The author and environmental organizations signaled intent to continue negotiations on the bill’s environmental safeguards and disclosure requirements.