RANCHO CUAMONGA >> Higher than normal levels of methane were detected in an Alta Loma neighborhood following a gas leak, according to initial findings from the South Coast Air Quality Management District.

The leak was reported May 8 in the area of Archibald Avenue and La Gloria Drive. The Southern California Gas Co. found a leaking 3-inch natural gas pipeline located in the street on Archibald Avenue and repaired it, according to officials.

Work, however, continues in the area “to remove trace amounts of natural gas trapped in the soil,” according to a SoCalGas statement. Residents report workers are on-site 24/7.

A spokesman said the company has not determined yet how long gas was leaking.

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Although the utility did not inform the air district of the leak, a member of the public complained, and air district inspectors began investigating May 19, spokesman Sam Atwood wrote in an email to this publication. Air samples were taken to test.

“In general, results from the mobile survey measurements in Alta Loma have indicated that levels of methane are typical in the vast majority of the area,” Atwood wrote. “However, elevated levels of methane were detected in instantaneous measurements in the areas near La Gloria and Archibald, the primary area of repair work, and also Lemon and Archibald.”

Methane, a colorless and odorless gas, is the main component of natural gas. High levels of methane are known for being flammable, Atwood said, but the levels found in Alta Loma are not high enough for that to be an issue.

Resident Rebecca Davies said that Friday marked the 18th day since workers showed up to address the leak. She said gas is being channeled through large holes in the ground and being incinerated.

Davies said SoCalGas workers have assured residents that they will stay until all the gas has been removed, but it wasn’t clear when that might be.

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“They have been working very hard to remove the subterranean gas, but they can’t see under the ground to know exactly how big this plume under the ground is,” she said.

She said her trees and plants had been dying for a period of time and had to be replaced. She believes she now knows what the culprit was.

“We are pleased to finally figure out why things have been dying,” Davies said. “It wasn’t the drought, it was the gas. I’m sure of that.”

Residents will now have to deal with other problems, such as replacing dead landscaping and visiting the doctor to make sure they don’t have health problems related to the leak.

“This is just step one,” she said. “The remediation is just step one.”