09790907 DX St 91 injector - The Geothermal Leasehold of the Union Oil Company at The Geysers, Sonoma County, California 07/21/1975
5 Documents in Project
Summary
SCH Number
2020040101
Lead Agency
Sonoma County
Document Title
09790907 DX St 91 injector - The Geothermal Leasehold of the Union Oil Company at The Geysers, Sonoma County, California 07/21/1975
Document Type
NOD - Notice of Determination
Received
Posted
9/10/2026
Document Description
The Geysers Power Company, LLC is proposing to drill a grass roots injection well DX-91. The well is located on an existing and fully disturbed well pad. Steam decline in the area will be addressed via the new injection well. Please refer to the attached Environmental Impact Report information and Sonoma County authorization for this proposed activity.
The proposed work summary entails the following: Drill 26" hole to 535', run 20" surface casing and cement in place. Directionally drill 17-1/2" hole to 1500', run 13-3/8" intermediate casing and cement in place. Directionally drill 12-1/4" hole to 4600', hang 9-5/8" liner and cement in place. Drill 8-1/2" hole to 8500', set on bottom 7" production liner with 8-5/8" receptacle. From surface, run 7" hangdown liner into 8-5/8" receptacle. Shut in well. Rig down.
Equipment to be utilized includes a standard drill rig that will fit within the existing well and pad footprint. Active work will be contained on the well pad that was created for equipment used to drill the original well. Other associated construction equipment may include a service vehicle, pickup trucks, and cement trucks. The project duration will be approximately 70 days.
Well Name: DX State 4596 – 91, API# 097-90907
Contact Information
Name
Maggie Harrington
Agency Name
Department of Conservation
Job Title
Analyst II
Contact Types
Responsible Agency
Phone
Email
Name
Jericho Reyes
Agency Name
Geysers Power Company, LLC
Job Title
Agent
Contact Types
Project Applicant
Phone
Name
Julia Smith
Agency Name
Permit Sonoma
Job Title
Planning Secretary
Contact Types
Lead/Public Agency
Phone
Location
Coordinates
Cities
Unincorporated Area
Counties
Sonoma
Regions
Northern California
Township
11N
Range
8W
Section
7
Base
MDBM
Other Location Info
Located in the Mayacamas Mountains approximately 72 miles north of San Francisco, California.
Notice of Determination
Approving Agency
Department of Conservation - CalGEM
Approving Agency Role
Responsible Agency
Approved On
County Clerk
Sonoma
Final Environmental Document Available at
State Clearinghouse: https://ceqanet.opr.ca.gov and/or CalGEM’s website at: http://www.conservation.ca.gov/calgem/CEQA
Determinations
(1) The project will have a significant impact on the environment
No
(2a) An Environmental Impact Report was prepared for this project pursuant to the provisions of CEQA
Yes
(2b) A Mitigated or a Negative Declaration was prepared for this project pursuant to the provisions of CEQA
No
(2c) An other document type was prepared for this project pursuant to the provisions of CEQA
No
(3) Mitigated measures were made a condition of the approval of the project
No
(4) A mitigation reporting or monitoring plan was adopted for this project
No
(5) A Statement of Overriding Considerations was adopted for this project
No
(6) Findings were made pursuant to the provisions of CEQA
No
Attachments
Notice of Determination
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