A construction boom of pipelines carrying explosive oil and natural gas from "fracking" fields to market -- pipes that are bigger and more dangerous than their predecessors -- poses a safety threat in rural areas, where they sometimes run within feet or yards of homes with little or no safety oversight, an NBC News investigation has found.
The rapidly expanding network of pipes, known as "gathering lines," carry oil and gas from fracking fields in many parts of the country to storage facilities and major "transmission lines." They are subject to the same risks - corrosion, earthquakes, sabotage and construction accidents -- as transmission lines. But unlike those pipelines, about 90 percent of gathering lines do not fall under federal safety or construction regulations because they run through rural areas, the Government Accountability Office reported in 2012.
Safety advocates and regulators have called for new regulations on the pipelines, but energy industry interests have pushed back. Any changes could be years away, if they happen at all, according to an analysis from the Congressional Research Service released early this month.
The risk didn't become apparent to Dave and Cheryl Goble, who live in rural Wyoming County, Pennsylvania, until long after a pipeline company land man knocked on their door in 2010 and offered to pay them to run a natural gas pipe across their property.
The Gobles signed a contract after being shown a plan where the line would run straight across their property, some distance from the house. But the pipe was ultimately buried in a trench that curves around their home, within feet of their porch, shaking their sense of well-being: If it were to fail, they now realize, their home could be destroyed.
"We'd never do it again, money or no money," said Cheryl Goble, 53, who grew up just down the dirt road where she still lives. "They think they can do anything that they want to. As long as you sign papers, they don't care about you afterward. They're gone."
The lack of oversight on rural gathering lines - historically low-pressure steel lines up to 12 inches around - was long justified by the perception that the risk of accidents was minimal. But the fracking boom has led to construction of new gathering lines that are both bigger and under higher pressure, making them virtually identical to transmission lines.
240,000 miles already laid, more on the way
More than 240,000 miles of gathering lines already exist in the U.S., moving oil and natural gas from wells and nearby storage areas to processing plants and transmission lines. And pipeline companies are rushing to get lines in the ground to meet the boom brought by the growth in horizontal drilling and hydraulic fracturing, commonly known as fracking, which has made it possible to recover oil and gas from hard shale formations. Some 414,000 additional miles of gathering lines could be built by 2035, found a 2011 report by the Interstate Natural Gas Association of America.
The Marcellus shale field, which extends across Pennsylvania, West Virginia and Ohio, accounts for 40 percent of the shale gas being produced in the U.S., according to the federal Energy Information Administration. Much of that is coming from the more than 7,000 wells drilled in Pennsylvania since 2004. Infrastructure to move it lags behind, so industry representatives arrive daily at the doors of rural Pennsylvanians, pipeline contracts in hand.
The Gobles say when they signed the contract for about $25,000, they were told the pipe would be laid some distance from their house. Then plans changed. The company ultimately placed it so it skirted the corner of the house and bent in an L-shape behind it. There was nothing the Gobles could do.
"The pipeline people might have been good to other people, but we don't agree with what they did down here," said Cheryl Goble. "I thought it was a trick."
Chief Gathering, the company that built to the pipeline, referred NBC News' request for comment to Regency Energy Partners, which purchased the line earlier this year. Regency did not address the Gobles' claims directly, but said the company was "committed to the safe construction and operation of its assets" and works "honestly and respectfully with landowners."
Pipelines are widely seen the safest way to transport natural gas. But accidents, including a 2010 explosion in San Bruno, California, that killed eight people and destroyed nearly 40 homes, have exposed ongoing issues even with regulated transmission lines, which typically connect storage facilities to large consumers like factories or to distribution centers.
And critics say that raises bigger concerns about lines that go unwatched.
"There is tremendous growth going on, and the reality is that it's really not regulated well," said Richard Kuprewicz, an independent engineer who has worked in the oil and gas industry for decades. "A 30-inch gathering rupture -- that can kill a lot of people."
There is no comprehensive record of fatalities or injuries caused by rural gathering lines, but a 2012 survey by two oil and gas industry groups reported that six people died and 16 others were seriously injured in gathering line accidents between 2007 and 2011. The causes of the accidents were not detailed in the survey.
That toll included an accident in June 2010 -- a few months before the San Bruno explosion - in which a work crew hauling rock out of a pit near Darrouzett, Texas, struck a gas pipeline. It ruptured and ignited, killing two workers.
Industry groups argue that these numbers were lower than those for regulated transmission lines, indicating gathering lines are safe.
Federal pipeline safety officials, however, have called for better oversight of the lines.
"What keeps me up at night? Gathering lines," Linda Daugherty, deputy associate administrator for field operations at the Pipeline and Hazardous Materials Safety Administration (PHMSA), the federal agency that regulates pipelines, said at a 2012 conference. "There are no safety standards applicable to those lines, and no safety agents or regulators looking at them."
Transmission lines must meet construction and welding standards, and be periodically inspected, cleaned and tested. Operators also must report all deaths and injuries and maintain integrity management plans.
Gathering lines in more populated areas or close to facilities like schools are subject to many of the same standards, but their country cousins are not.
Gathering lines in "Class 1" areas like the one where the Gobles live -- defined as having fewer than 10 habitable dwellings per mile within 220 yards of pipe's center line -- are subject to none of these rules. While states can pass their own regulations, most have not.
As of 2013 Pennsylvania had more than 2,600 miles of class 1 line and about 990 miles of other classes to move shale oil and gas, according to records obtained from the state's Public Utility Commission. And more is coming. Between 10,000 and 25,000 miles of gathering pipeline could be built by 2030, according to an estimate by The Nature Conservancy.
Safety advocates also worry that the fact that ownership of the pipes often changes after they are built, could further compromise safety. The pipeline that runs by the Gobles' home, for instance, has been sold twice since its construction in 2012.
Proposal to tighten rules stalls
PHMSA, the federal pipeline regulator, indicated in 2011 it might write new regulations on gathering lines and proposed gathering risk data as a first step. But the proposal quickly ran into resistance from the industry.
"There is little need for additional federal regulation of gathering lines," the American Petroleum Institute and the Independent Petroleum Association of America wrote in response to the rulemaking proposal. More regulations focused on rural areas could slow construction of much-needed lines, spread inspection and oversight too thin and harm operators of older wells that are only marginally profitable because they produce small amounts of gas, which that make up about 10 percent of the national supply.
PHMSA closed comments on its proposal to collect such data in 2012. There has been no action on the plan since.
In response to a query from NBC News, PHMSA Administrator Cynthia Quarterman said that the agency is "developing a long-term comprehensive solution to enhance the safety of gathering pipelines through rule making," but provided no timeline.
Other energy industry groups say new rules may be in order, but said they should focus on lines in more developed areas, such as towns or residential subdivisions.
"We don't oppose regulations, we just believe, and ask, that new regulations be risk based," Jeff Applekamp, a spokesman for the Gas Processors Suppliers Association, said in an email to NBC News.
Carl Weimer of the nonprofit Pipeline Safety Trust argues that gathering lines should be regulated like transmission lines, though with some flexibility depending on location.
"It's the same type of pipe, it's the same pressure as a transmission line, so the theoretical risk is the same," said Weimer. "If the risk is the same on paper, the regulation should be the same as well."
In the absence of expanded federal oversight, PHMSA has encouraged states to set their own rules. Some have done so.
Ohio last year passed a bill that applies federal regulations on gathering lines in populated areas to their rural counterparts. Texas, too, last year passed regulations opening the door for federal oversight of rural lines -- though not until September 2015 at the earliest.
Despite new pipeline rules passed in Pennsylvania in 2012, Class 1 lines remain unregulated, leaving landowners like the Gobles and their neighbors at risk.
Kay Gilbert, a schoolteacher who lives nearby, tries not to think about the potential danger of the 24-inch line that stretches behind the house her husband Butch built. Anticipating future development in the area, the pipeline company built that 34-mile line to higher Class 2 standards. Nevertheless, worries linger.
"First and foremost, I don't want to be blown to bits," Gilbert said. "I know it's not an imminent threat, but in the back of your mind you know it could happen, because it has."