A mail box sits on an abandoned well pipe near blooming peonies, logs snag on metal casings rising out of a creek, children swing next to rusted pump jacks.

Jennifer Oldham reports for Bloomberg:

In Pennsylvania, birthplace of the U.S. oil industry, century-old abandoned oil wells have long been part of the landscape. Nobody gave much thought to it when many were left unplugged or filled haphazardly with dirt, lumber and cannon balls that slipped or rotted away.

But the holes — hundreds of thousands of them pockmark the state — are the focus of growing alarm, especially those in close proximity to new wells fracked in the Marcellus shale formation, the nation’s largest natural-gas field. They leak methane, which contaminates water, adds to global warming and occasionally explodes; four people have been killed in the past dozen years.

“We had so much methane in our water, the inspector told us not to smoke a cigar or light a candle in the bath,” said Joe Thomas, a machinist who lives with his wife, Cheryl, on a 40-acre farm with at least 60 abandoned wells. Patches of emerald-hued oil leech to the surface, transforming the ground into a soupy mess.

Hundreds like the Thomases live over lost wells.

Now the state’s attorney general is reviewing rules requiring drillers to document wells within 1,000 feet of a new fracking site. This puts Pennsylvania among states such as California, Texas, Ohio, Wyoming and Colorado confronting the environmentally catastrophic legacy of booms as fracking and home development expand over former drilling sites.

As the number of fracked wells increases, so does the chance they might interact with lost wells. Pennsylvania regulators have documented several instances of fracking too close to an abandoned hole, causing methane to leak into homes, the air or water.

At least 3.5 million wells have been drilled in America since operators plumbed the first hole in the small Pennsylvania town of Titusville back in 1859.  It was oil pumped from this rugged landscape, near the state’s western border with Ohio, that John D. Rockefeller started refining a few years later in a venture that would evolve into the Standard Oil Trust.

Today, about a quarter of the 3.5 million wells across America are active, leaving an inventory of 2.6 million that are no longer in use. The locations of some inactive wells are documented, but little is known of the whereabouts of wells drilled before permitting regulations were enacted 60 years ago. Only 10 percent of abandoned wells are recorded in state databases — meaning there are years of work ahead to locate and plug them. Seth Pelepko of Pennsylvania’s Department of Environmental Protection says the agency has plugged only 3,000 such sites in 30 years.

Regulators are ramping up detection efforts, including testing the use of drones equipped with magnetometers. For the moment, however, they rely on a low-tech solution of “citizen scientists” who hunt for leaking wells near watersheds and recreation areas in the Allegheny National Forest.

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