Southern California Gas Co. on May 7 boosted its estimated cost for the massive leak at its Aliso Canyon natural gas storage facility between October 2015 and February 2016 to around $954 million, up 4.4% from the estimate of $913 million last quarter, according to a quarterly report with U.S. financial regulators.

SoCalGas, a unit of California energy company Sempra Energy, warned the “estimate may rise significantly” due to pending lawsuits, possible fines and other costs. It said costs not covered by insurance or delays in receiving insurance payments “could have a material adverse effect on SoCalGas’s and Sempra Energy’s cash flows, financial condition and results of operations.”

The utility said the latest estimate included $928 million of costs already recovered or likely to be recovered from insurance. It said about 60% of the total cost was for temporary relocation of residents who live near the facility, which is close to the Porter Ranch neighborhood in Los Angeles, including cleanup costs.

Aliso Canyon, with a capacity of 86 billion cubic feet (bcf), is SoCalGas’ biggest storage facility. State regulators estimated 4.62 bcf of gas leaked at Aliso Canyon. One billion cubic feet is enough gas to supply about 5 million U.S. homes for a day.

The facility represents 63% of the utility’s gas storage capacity, making it a key part of the company’s ability to deliver fuel to customers, especially on the coldest days when demand for heating is highest and the hottest days when a lot of gas is used to generate power for air conditioning.

State regulators have limited the amount of gas SoCalGas can inject into Aliso Canyon to a total of 24.6 bcf. They have also said the company can only withdraw gas from the facility when other options are not available to meet demand.

Many residents and government officials want SoCalGas to shut the Aliso Canyon facility.