Traces of Arsenic Found in Gas Pipes for Industrial Users

Traces of arsenic have been found in the pipeline system used by Southern California Gas Co. to transmit natural gas to industrial customers in Orange County, Fontana and Ontario, company officials disclosed Thursday.

Tests conducted by the gas company showed that the presence of an organic compound, consisting of arsenic and sulfur, in the gas stream poses no significant health risk to customers or the public, said Debra Reed, manager of environmental engineering for the gas company.

Problem in Lines

In the case of industrial customers, Reed said, the only concern is that a buildup of the substance may cause a failure in the gas company’s pressure control equipment or in the customers’ lines. Residential customers are unlikely to be affected by the problem, since gas pressure normally is reduced to less than 1 pound per square inch by the time it is used in the home, compared to pressures ranging from 5 pounds per square inch to several hundred pounds per square inch for industrial users, she said.

“The problem was in our lines, and we didn’t feel this was a problem that our customers would see. Unless they are breaking open a pipeline in their facility, there is no way they would encounter any material. We told them to be aware of the material during routine equipment maintenance,” Reed said.

To prevent inhalation of the substance and contact with the skin, pipeline workers should dampen the arsenic-sulfur compound and wear protective gloves, Reed said. Arsenic is highly toxic if ingested and inhaling it is a known to cause cancer.

“That’s a safety precaution we are recommending for our employees. You don’t want to get it under your fingernails and then eat,” she said.

The gas company discovered the problem in mid-February, when a malfunction in the pressure regulators showed up on its monitoring system, company officials said. On Wednesday, the company notified about 104 industrial customers by telephone and by mail and asked them to report immediately any symptoms found in their equipment, Reed said.

About 25 of those industries are in Orange County, and the rest are in the Ontario and Fontana areas, Reed said. Officials refused to release the names of the companies but said they include chemical facilities, oil companies, paper plants and major manufacturing facilities.

According to the gas company, the problem has been mostly confined to its own pipeline, but deposits of the compound have been found at one industrial site. Gas company officials refused to identify that company.

The state Public Utilities Commission has also been notified of the problem, gas company officials said.

Small deposits of the white, chalky substance have formed at or near points in the pipeline where high-pressure gas from the source is filtered and reduced to a lower pressure suitable for industrial use, Reed said. In some cases, the deposits have caused operational problems by clogging regulators inside the pipes that control the pressure, causing gas to be released at higher pressures, she said.

“The regulators in our system control the pressure. They have tiny orifices in them. And if they get clogged up, it can affect their operation. It’s like if you have a can of hair spray and over time, the hair spray clogs the hole in the nozzle and prevents the hair spray from coming through when the button is pushed,” she said.

Symptoms of the pressure problems that could occur in industrial facilities may be a popping noise when a gas burner is lighted, a high or lifting flame in the main burner or pilot, gas leakage from valves or fittings, partial gas outages and low pressure or complete loss of pressure, officials said.

“We are monitoring it now to ensure that no more is coming in. We installed additional filtration equipment on our lines and modified some existing filtration equipment to try to remove what presently is in the system, but we’re not sure if we’ve removed it all yet,” Reed said.

Southern California Gas Co. officials said they have not determined the exact origin of the compound or the cause of the deposits. Officials said, however, it is common to find small deposits of sulfur in the pipes. Sulfur generally does not pose a health threat.

Reed said she could not say exactly how much arsenic was found in the pipes, only that they are minuscule deposits. Officials said the amount of arsenic found is far below the significant risk level established by law.

“In some cases, it’s barely visible, just enough to get a sample of the material. In other cases, you can see it, but you can’t collect it,” she said.

According to Rich Puz, a gas company spokesman, the problem has affected 50 to 100 miles of the company’s 40,000-mile pipeline system.

Most of the gas used in Southern California is bought from gas producers in Texas, New Mexico and Oklahoma through these long-distance, high pressure transmission lines, he said.

“The gas comes from lots of gas producers and it is conceivable--but we don’t know--that any one of them could have had something happen to their system that could have produced the substance in the pipeline and brought it to California,” Puz said. “If it were a continuing problem, it would be easier to trace it back to the roots. But since it’s not, we don’t see much use in tracking it down.”