After almost two years out of service, Southern California Gas Co. (SoCalGas) plans to restart Line 235, a 30-inch diameter pipeline that carries natural gas from the Arizona border through the high desert and into the Los Angeles Basin.

Since October 2017, when an explosion and fire ripped apart a portion of SoCalGas' Line 235 in the middle of a sparsely populated part of the high desert 150 miles northeast of Los Angeles, advocates for transitioning away from fossil fuels have called for letting the pipeline remain idle, while the Sempra Energy utility has said it is vital to energy reliability for more than 20 million people.

While the repairs have taken longer and cost more than originally contemplated, SoCalGas officials stressed that they have been dealing with a remediation plan that called for 10 job sites to collectively replace separate pipe segments totaling 3.4 miles, replacing cathodic protection and installing new mainline valves.

SoCalGas has targeted July 21 for the restart of Line 235 after the completion of work that began last summer, following a root-cause analysis by a third-party expert that took six months, and several more months to develop a detailed remediation plan.

Higher retail utility rates for gas and electricity have been attributable to the combination of the transmission pipeline outages and reduced operations at Aliso Canyon, the state's biggest underground gas storage facility. The SoCalGas storage operations have been severely restricted since a four-month storage well leak in 2015.

State regulators have estimated that customers of Southern California Edison Co. absorbed an additional $800 million in charges last year mostly due to the storage facility and pipeline outages.

Even with the prospects for bringing Line 235 back this month, SoCalGas faces continuing calls to  shut down Aliso Canyon storage operations, and it has other pipelines in the high desert that may have to be shuttered for repairs. The high desert soils are particularly corrosive for pipelines that have been in the ground for more than 50-60 years, according to gas utility engineers.

Looping of Line 235 is provided through Lines 3000 and 4000, which stretch from the state border to the metropolitan area. Line 4000 has experienced corrosion-driven leaks, SoCalGas has reported, and it may be taken out of service next for repairs.

"Crews face several challenges replacing miles of buried pipe in a remote area that is difficult to get to, has restricted access and challenging terrain, extreme weather, and rigorous environmental permit requirements," said SoCalGas spokesperson Christine Detz.

Work on Line 235 began on segments not requiring permits. For the bulk of the job, a final permit was not obtained until January. Crews have worked 12-hour days, six to seven days a week since last January, Detz said.