Now an exhaustive examination of the methane problem in Western Colorado offers a strong scientific repudiation of those arguments. The study matched methane found in dozens of water wells with the same rock layer – a mile and a half underground – where gas companies are drilling. The scientists didn’t say exactly how the gas reached the water, but they indicated with more clarity than ever before that a system of interconnected natural fractures and faults could stretch from deep underground gas layers to the surface.
“It challenges the view that natural gas, and the suite of hydrocarbons that exist around it, is isolated from water supplies by its extreme depth,” said Judy Jordan, the oil and gas liaison for Garfield County, Co. and a hydrogeologist who has worked with DuPont and Pennsylvania’s DEP. “It is highly unlikely that methane would have migrated through natural faults and fractures and coincidentally arrived in domestic wells at the same time oil and gas development started, after having been down there …for over 65 million years.”
Drinking water with methane, the largest component of natural gas, isn’t necessarily harmful. The gas itself isn’t toxic – the Environmental Protection Agency doesn’t even regulate it – and it escapes from water quickly, like bubbles in a soda. But the gas becomes dangerous when it evaporates out of the water and into peoples’ homes, where it can become flammable. It can also suffocate those who breathe it. According to the Agency for Toxic Substances and Disease Registry, as the concentration of gas increases it can cause headaches, then nausea, brain damage and eventually death.
The carefully documented accident in Ohio in December, 2007 offers a step-by-step example of what can happen when drilling goes wrong.
A spark ignited natural gas that had collected in the basement of Richard and Thelma Payne’s home outside Cleveland, shattering windows, blowing doors 20 feet from their hinges and igniting a small fire in a violent flash. Fearing another explosion, firefighters evacuated 19 homes. Investigators determined that somehow gas had seeped into the drinking water aquifer and migrated up through the plumbing.
To reach natural gas, a well bore is drilled through dozens of geologic formations stacked like layers in a cake until it reaches the layer holding gas. In Ohio, gas is produced from almost 3,700 feet, or three-quarters of a mile, below. In Colorado or Pennsylvania, wells can be a mile or two deep – far below drinking water aquifers.
The deep gas layers are under extreme pressure from the weight of the earth and water above. When the drill bit sinks down, the tight seal of each layer is broken and the pressure is released.
To keep the gas and drilling fluids from leaking into the natural environment, drilling companies insert as many as three concentric rings of steel pipes inside the well bore to isolate what flows through them. When the bore passes through sensitive areas – such as drinking water aquifers – cement is pumped into the gap between the rings of pipe to ensure an impenetrable seal.
The investigation into the explosion at the Paynes’ home found that a drilling company working nearby had failed to properly build that protective cement casing. Six weeks before the explosion, the company, Ohio Valley Energy Systems, pumped cement into the well casing but couldn’t fill the gap, evidence that somewhere a crack was allowing the cement to seep out.
Eventually the company shut down the well. But the gas formation had already been punctured, and its contents were trying to escape. The gas collected inside the well until 360 pounds of pressure built against the valve at the top. That was enough, state investigators wrote, to force the gas out of the well bore by any means it could find.
Ohio Valley Energy Systems did not return calls for comment on the state’s findings.