Imperial Irrigation District customers suffered a widespread power outage April 4 after a 7.2 earthquake struck 16 miles southwest of Guadalupe Victoria, Baja California, Mexico, at 3:40 p.m. The temblor damaged a substation, according to the California Independent System Operator. “The system held up remarkably well, considering the magnitude of the quake and its proximity to the Imperial Valley,” stated IID administrative services chief Mike Campbell. “Except for a few pockets in outlying areas of Imperial County, service was largely restored within the first several hours following the event, although isolated problems remain.” Following the quake, the district set up an emergency operations center at its headquarters to assess problems in its extensive power and water distribution systems. The temblor affected generators. Sempra Generating’s 625 MW Termoelectrica de Mexicali remained offline at presstime, according to spokesperson Scott Crider while the company investigates potential damage. InterGen’s 1,065 MW La Rosita plant was damaged by the earthquake, according to InterGen spokesperson Corbin Keirnan. The four-unit facility, 38 miles from the epicenter, was being reviewed for the extent of the damage to the switch yard at press time. The turbines are also a concern. They are “very sensitive,” noted Keirnan. She added that shifting as much as 1/8th of an inch could result in harm. The units were down for maintenance during the earthquake. There is no timeline for them to return to service, according to Keirnan. The San Onofre Nuclear Generating Station’s “Seismic Recording System activation with ground motion [was] readily felt by control room personnel. Plant inspections performed to date show no observable damage to systems or structures, according to the Nuclear Regulatory Commission. “No equipment issues [were] found” from the earth’s movement, reported primary power plant owner Southern California Edison to federal regulators. To the north, the Palo Verde nuclear power facility reported to federal regulators, “There are no challenges to fission product barriers or radiological release, and plant conditions offer no possibility of adverse impact on health and safety of the public.” The Mexicali earthquake didn’t disturb California’s grid, according to California Independent System Operator spokesperson Gregg Fishman. “We are calling on additional generation to replace the transmission capacity that is out of service due to the earthquake,” he said. Sempra Pipelines & Storage, which has natural gas lines in the area, did not return repeated calls for comment. Sempra’s LNG terminal on the West coast near Rosarito Beach was not shut down and “sustained no damage,” stated to Sempra LNG spokesperson Katheen Teora. Tangentially, on March 31, a 230 kV line went down from Imperial to Rosita, according to Richard Clark, California Public Utilities Commission Consumer Protection & Safety director.