Pacific Gas and Electric Company (PG&E) submitted three Notices of Intention (NOIs) to drill three new replacement underground gas storage (UGS) wells at the McDonald Island Natural Gas Storage Facility (McDonald Island Facility) in San Joaquin County (Project). The three new replacement UGS wells will be installed in the McDonald Island Facility, an existing facility of an investor-owned utility that is used to provide natural gas services. The McDonald Island Facility is on the man-made McDonald Island, in the Sacramento-San Joaquin Delta, in San Joaquin County; approximately 40 miles south of Sacramento and 10 miles west of Stockton. McDonald Island is 5,900 acres in size and bounded on the north by San Joaquin River, on the west by Middle River and Latham Slough, and on the south by Empire Cut. The McDonald Island Facility on the island is approximately 2,760 acres. The remaining acreage is actively farmed. McDonald Island Facility is currently comprised of 88 wells: 69 active gas storage wells, 2 idle gas storage wells, 5 abandoned gas storage well, 4 out of service gas storage wells, 7 active observation wells, and 1 idle observation well.
The purpose of the proposed Project is to replace a total of 45 million cubic feet per day (MMCFD) of gas (15 MMCFD per well) deliverability of an estimated 576 MMCFD that was lost from wells being converted to tubing and packer and outage associated with the ongoing inspections in compliance with CalGEM’s 2018 UGS regulations that establish standards for the design, construction, and maintenance of all gas storage wells. The McDonald Island Facility is PG&E’s largest gas storage field and has a maximum capacity of 82 billion cubic feet (BCF). The McDonald Island Facility provides Northern California with a reliable supply of natural gas. In the winter, the McDonald Island Facility can provide up to 25 percent of Northern California’s peak-day gas demand.
In 2018, CalGEM promulgated regulations that establish standards for the design, construction, and maintenance of all gas storage wells. The regulations include stringent well construction standards that are required to ensure that gas storage wells are safe and will maintain their integrity over time. The well construction standards promote environmental safety by focusing on leak prevention.
Meeting the new well construction standards requires operators to upgrade and rework all existing gas storage wells or plug and abandon any nonconforming wells. The required well construction upgrades diminish the throughput capacity of each new or reworked gas storage well. Once the new well construction standards are complied with, the only way to maintain the overall throughput capacity of a UGS facility is to add replacement gas storage wells. The new replacement gas storage wells must comply with the regulatory standards and are necessary to make up for lost deliverability that was incurred due to wells that were permanently removed from service. If approved, the proposed Project will meet CalGEM’s UGS construction standards set forth in CalGEM’s regulations.
The proposed Project consists of CalGEM approving three permits for PG&E to install the three new replacement gas storage wells, listed below, in the McDonald Island Gas Field.
API # Well Name
0407720742 McDonald Island Farms 01A-N
0407720741 Turner Cut 01B-N
0407720743 Lil Mac 2