A South Coast Air Quality Management District (SCAQMD) hearing board last Saturday ordered the permanent closure and other steps related to Southern California Gas Co.'s (SoCalGas) leaking natural gas storage well (see Daily GPI, Jan. 19).
The SCAQMD board will conduct a follow-up hearing Feb. 20 to review the status of the utility's progress.
The action, which mandates something the Sempra Energy gas-only utility has been planning to do anyway, came at the same time the utility was getting to within 200 feet of its target in drilling a relief well for use in finally plugging the three-month-old leak at the 8,500-foot depth of the well (see Daily GPI, Dec. 16, 2015).
SoCalGas was ordered by the SCAQMD hearing board to "take immediate action to minimize odors and air pollution" from the leak, whose volumes continued to subside in readings taken last week, compared to peak levels reached last November.
In addition to the "immediate action," SoCalGas is ordered to "thoroughly inspect" all of the 114 other storage wells at the 86 Bcf capacity, 3,600-acre Aliso Canyon underground storage facility, and when the leak is plugged to permanently shut down the well.
Other steps mandated by the board include:
SoCalGas funding an independent study to assess any potential health effects on residents from the gas leak, including the effects of exposure to the odorant (mercaptan) placed in natural gas;
Development and implementation of an enhanced leak detection/reporting program for all gas storage wells;
Infrared camera monitoring of the leaking well for 30 days after the leak is stopped; and
Providing the SCAQMD with statistics on withdrawals and injections at Aliso Canyon, along with all additional statistics so a final calculation can be made on the amount of methane leaked.
The order will remain in effect until Jan. 31, 2017, according to Barry Wallerstein, SCAQMD executive officer, who said the mandates are to "help prevent another major leak in the future."
SoCalGas on Monday said its relief well has now reached a depth of 8,400 feet, but although close in terms of the distance from the leaking well's base, "the objective of this phase is to close the distance while precisely aligning the relief well with the target well. This final phase requires precision and accuracy, which takes time," said a utility spokesperson.
When the relief well reaches the target, the drilling operation will transition to a plugging operation, pumping heavy fluids and drilling mud into the target well to stop the gas flow. When that is accomplished cement will be pumped in to displace the fluids and mud providing an initial seal. Ultimately, SoCalGas will confirm with state regulators that the well is sealed and residents will be allowed to return to their homes.