LOS ANGELES (KABC) -- A Los Angeles city councilman is calling for an investigation into why customers of Southern California Gas Company have seen sharply higher bills this winter.Some customers have seen bills four to six times higher than usual for this time of year, according to Councilman Mitchell Englander. He suspects the utility is passing on the costs of its Alison Canyon gas leak onto its customers across Los Angeles County."This bill spiking comes at a time when SoCal is experiencing a major disaster at its Aliso Canyon facility," Englander said. "I am simply not buying that these two incidents are not related. It appears that the entire Los Angeles basin is now feeling the effects of the Aliso Canyon Gas Leak."A spokesman for SoCal Gas said the bill increases are not related to the gas leak, but blames them instead on the region seeing a colder-than-usual winter.Englander, who is skeptical of that explanation, plans to submit a City Council resolution asking the California Public Utilities Commission to investigate the rate increases. The CPUC is already investigating the natural gas leak at the facility near Porter Ranch in the San Fernando Valley.The leak has forced thousands of people in the area to leave their homes because of odor and health concerns.Also Tuesday, U.S. Rep. Brad Sherman, D-Sherman Oaks, who lives in Porter Ranch near the site of the leak, said he plans to introduce federal legislation designed to prevent future gas leaks.Sherman's proposed Natural Gas Storage Safety Act would direct the federal Department of Transportation's Pipeline Hazardous Materials Safety Administration to implement new safety standards for natural gas storage facilities.Sherman said he has spoken to President Barack Obama and received assurances that White House staff would work with Sherman to adopt natural gas storage regulations as authorized under existing law. If that doesn't happen, Sherman said his bill would force the agency to act."This disaster could have been prevented," Sherman said. "There are currently no federal regulations for most natural gas storage facilities. State regulations are weak or non-existent. The Aliso Canyon disaster proves that we cannot leave oversight to the gas industry."