Minor natural gas leak reported by SoCalGas July 2, 2016
after 2:00 p.m. on Saturday afternoon, July 2, 2016, SoCalGas notified SCAQMD
of a “minor non-hazardous [natural
gas] leak indication" discovered by SoCalGas personnel during a
routine inspection of Well SS-10. SCAQMD inspectors were dispatched to
the site immediately to investigate. No
natural gas odor complaints associated with the site were reported to SCAQMD by
the public, and SCAQMD inspectors were unable to detect natural gas odors
in the surrounding community. SoCalGas
excavated an area near Well SS-10 and confirmed that the leak originated at a
threaded coupling on a natural gas pipe running ~18 inches below the ground
surface and adjacent to the well. SCAQMD
inspectors detected and recorded the leak using a FLIR camera and collected an ambient air sample using a
SUMMA canister. SoCalGas depressurized
the line and began making repairs, which were completed by 9:30 the following
morning (Sunday), shortly before SCAQMD inspectors returned to the site for
SoCalGas determined that the buried
pipe with the leaking component led from the facility’s on-site gas processing plant to
injection/withdrawal Well FREW 5. According to SoCalGas representatives, this
line should not have been pressurized.
On further inspection, they found a leaking valve that was allowing
natural gas to pass downstream. When SCAQMD
inspectors inspected Well FREW 5, they found that the well was not
operational and had been disconnected. Inspectors
did not observe or detect emissions at Well FREW 5.
A review of ambient air data from
SCAQMD fixed air monitoring stations in the Porter Ranch community before,
during, and after the time the leak was discovered and repaired showed typical
readings, with a maximum hourly methane level of 2.15 ppm, indicating that the
leak had no appreciable effect on methane levels in the Porter Ranch area.
Southern California Gas Company (SoCalGas) operates the Aliso Canyon natural gas underground storage facility at 12801 Tampa Avenue in Northridge, CA 91326. On October 23, 2015 SoCalGas discovered that Well SS25 used to inject and withdraw natural gas from the underground storage reservoir at their Aliso Canyon facility was leaking. On February 18, 2016, the California Department of Conservation, Division of Gas and Geothermal Resources (DOGGR) provided notice to the public confirming that Well SS25 at the Aliso Canyon Gas Storage Facility has been successfully sealed.
South Coast Air Quality Management District (SCAQMD) and California Air Resources Board (CARB) staff have jointly developed a set of criteria to determine when air quality in the surrounding communities of the Aliso Canyon facility has returned to typical conditions - a checklist to determine when the air quality is no longer being impacted as a result of the leak. Click on the following links for information about:
SCAQMD staff is at the Aliso Canyon facility and the surrounding community on a daily basis to observe and monitor operations and to conduct ambient air measurements both within the facility and offsite in Porter Ranch and surrounding communities. SCAQMD will continue to monitor ambient air levels and provide updates on this website.
Information about other actions SCAQMD has taken in response to the natural gas leak from Well SS25 is available at the links below:
Links to other agencies participating in the response to the Aliso
Canyon gas leak are available here.