LOS ANGELES – Earlier this summer, thieves in Pico Rivera, Calif., made off with a 200-pound brass bell from a Catholic church. Burglars around California have torn up train tracks, carted off bleachers, nabbed park statues and helped themselves to copper wiring serving neighborhoods, hospitals and airports.

The state is in the throes of a metal theft epidemic, fueled by scrap yards’ willingness to pay high prices for copper and steel that can be resold to hungry factories in Asia.

In Southern California, a proliferation of unpermitted scrap yards — which have set up shop here to take advantage of access to the ports of Los Angeles and Long Beach — has exacerbated the problem.

Regulators acknowledge that, at times, they have been unable to keep up with the number of illegal operations and the environmental threat they pose. And in their eagerness to cash in on an export trade worth $7 billion annually, even some permitted scrap yards are ignoring laws designed to stem metal theft.

The task of ferreting out metal theft in Los Angeles County is left mainly to two men: Kevin Romine, a detective with the Los Angeles Police Department, and Detective Dave Chapman, a Los Angeles County sheriff’s deputy.

According to Romine, at least half the metal, excluding iron, in city scrap yards probably is stolen. In the year he’s been on the job, he has shut down a dozen unpermitted yards in the city of Los Angeles alone.

“I learned a long time ago, it’s more than I can handle,” Chapman said.

On a recent morning, he and a civilian investigator drove through the Alameda Corridor — a 20-mile freight rail route linking the ports to downtown Los Angeles — in search of scofflaw scrap operations. They passed one metal recycling business after another until Chapman pulled into one that didn’t appear to have a sign.

“This is a pop-up,” he said. “This wasn’t here a couple of months ago.”

Workers were loading hunks of car engines and transmission housings into a shipping container plunked down in the middle of a yard. There was no office, just a badly ventilated trailer surrounded by piles of metal. In a far corner of the yard, a worker was stripping copper wire.

“What do you call this place?” Chapman asked a man who came out of the trailer. The worker, who did not give his name, said one side of the yard was known as “S” metals; the other side had a different name.

Chapman could see no obvious signs that any of the metal there was stolen. But other times, he said, the evidence has been glaring.

He and his partner recently saw a man trying to sell bread racks right out of a bakery truck. While they were interviewing that suspect, Chapman said, another man showed up at the yard looking to sell municipal storm grates, but disappeared before officers could ask questions.

In 2007, the U.S. Department of Energy estimated that metal theft was costing businesses $1 billion a year nationwide. Copper theft, in particular, “disrupts the flow of electricity, telecommunications, transportation, water supply, heating, and security and emergency services, and presents a risk to both public safety and national security,” a 2008 FBI report said.

Four years ago, California was among the first states to pass laws requiring that sellers provide photo identifications to scrap yards and wait at least three days for payment for many metals. On the purchasing side, the yards were obligated to maintain records and make an honest effort to determine whether the sellers actually owned the material they were peddling.

But lawmakers, legitimate scrap operators and police said the laws haven’t been very effective, in part because officials were given little funding for enforcement.

“It’s a tremendous problem,” said state Sen. Anthony Cannella, who held a hearing on metal theft in California’s hard-hit Central Valley earlier this year. “It’s very expensive, and it’s very dangerous.”

In California, at least six people have electrocuted themselves in the process of pilfering copper wire in the past two years, according to media and coroners’ reports.

Cities across California are removing historical plaques for safekeeping, installing security covers on electrical boxes and embedding GPS tracking devices in coils of copper wire at often-hit locations.Modesto’s airport lost its runway lights not once but twice in the past few years, most recently in January, according to airport manager Jerome Thiele. Safety wasn’t compromised. But Thiele said he didn’t want to discuss how the thieves made off with the wiring, because “the bad guys will read this and go hit other airports.”

As the problem has increased, in part because of surging copper prices, officials in some parts of the state have cracked down.

A Contra Costa County, Calif., task force — composed of police and utility company and railroad officials — recently conducted a sting against eight recycling operations in which undercover officers offered to sell suspicious metal. Seven buyers purchased the material without following state requirements. The eighth called police, according to officials.

In Sacramento, Calif., officials secured access panels after 10,000 of the city’s 40,000 streetlights went dark because copper wire had been stolen from light boxes in the past 18 months, costing more than $1.5 million to fix.

“It was absolutely out of control,” said public works Director Jerry Way.

This year, state lawmakers have introduced seven bills to help tackle the problem. Two were approved, including one that would increase the fine to $1,000 for metal recyclers who knowingly buy material stolen from government or utilities. Several others are pending, including one that would make it a crime for recyclers to buy manhole covers, back-flow devices or fire hydrants without written proof of ownership.Established metal recyclers say their businesses help keep discarded material out of landfills and are being undercut by rogue operators. And they are pushing for tougher enforcement of existing laws.

“In other states, they have people who actually enforce the law,” said Jeff Ferrano, attorney for SA Recycling of Anaheim, Calif., one of the state’s largest metal recyclers.

In parts of the Central Valley, where farm equipment has been a particularly rich target, some residents are taking the law into their own hands.

Cannon Michael said that over the past two years, his Los Banos, Calif., farm has suffered $50,000 in losses from metal theft, including the copper wire from his irrigation pumps. Fed up, he and his neighbors bought guns and got permits to carry concealed weapons.

This spring, Michael said, he laid tire-puncturing spike strips across farm roads. The strips had been there only a few weeks when Michael’s water pump was hit again.

The tracks of the punctured car tires led police to two thieves, one of whom had been convicted in a theft six months earlier.

Some in the Central Valley say much of what is stolen there most likely finds its way to Los Angeles County, where they say operators will buy it, no questions asked.Mona Howerton, who with her husband runs Williams Recycling in the Florence-Firestone neighborhood, agreed. She said the couple often alert authorities when people show up trying to sell material that obviously is stolen.

But if they won’t buy it, there are plenty of people who will.

“It’s easy to come sell it down here because there’s so many of these little rogue operations,” Howerton said. “There’s no consequence.”