Appalachian Basin

STUDY: Naturally-Occurring Methane “Ubiquitous” in NE Pa. Groundwater

A new study in the peer-reviewed journal Groundwater found that naturally-occurring methane is ubiquitous in northeastern Pennsylvania as the region’s groundwater is contained in a hydrocarbon bearing rock that is interspersed with water wells that lack structural integrity.

Time and again, opponents of shale development have pointed to cases of alleged methane contamination of water wells in northeastern Pennsylvania as evidence of hydraulic fracturing contaminating water.  Many examples abound, but the most recent comes from Franklin Forks, Pa., where activists claimed Marcellus Shale development caused a family’s water well to become infused with dangerous levels of the gas. Regulators eventually determined the situation was due to natural causes, but not before the claim drew widespread media acclaim, the attention of celebrities like Yoko Ono and countless activists working overtime to block the advance of responsible shale development in neighboring New York.

It’s really the same old game:  Activists make a claim that shale development impacted water before a scientific investigation shows the claim to be unfounded. In the interim, we see inflammatory headlines about water pollution and environmental damage, all based on claims of harm derived purely from ideological predisposition.  While that may have worked in the past, a new study featured in Groundwater, the peer-reviewed journal of the National Groundwater Association, provides some much needed context regarding methane “contamination” from Marcellus Shale development in northeastern Pennsylvania.

The peer-reviewed study examined over 1,700 water wells in gas-producing and non-gas producing areas, determining that “methane is ubiquitous in groundwater” in the region, and that it is unrelated to Marcellus Shale development.  In fact, the study noted that over 78 percent of the sampled water wells exhibited detectable methane concentrations.  Of these, some 3.4 percent of the sample exceeded action levels at which corrective action is recommended by the Pennsylvania Department of Environmental Protection.

The study also examined over 200 years of records, all of which pointed to the fact that methane has been present in the area’s groundwater before anyone even considered drilling a well into the Marcellus Shale.  In its review, the study highlighted just a few of the many historical examples of methane in the region’s groundwater:

  • “Historical documentation suggests that the presence of methane gas in the shallow subsurface has been observed for over 200 years in Susquehanna County…”
  • “There are several dozen instances of flammable effervescing springs and water wells dating back to the late 1700’s…”
  • “Water well drillers have frequently reported encountering gas during drilling, particularly in valleys and other low-lying areas…”

The researchers found that the primary culprits for methane concentrations are (1) the source of the region’s drinking water, (2) the structural integrity of water wells in the region, and (3) natural factors such as topography that can lead to variations in the levels of methane.

The region’s primary source of drinking water – the Catskill Formation – is actually a hydrocarbon rich rock that has been tapped for numerous gas and oil wells over the course of its history.  The study noted, “the 1881 publication ‘The Geology of Susquehanna and Wayne County’ reported significant volumes of gas during the drilling of an oil boring in the Catskill Formation to a depth of 680 feet.”  The researchers found hydrocarbon generation in shallow geology to be rather common in the region as “Several gas fields in the past century have produced from formations less than 3,000 feet below surface in northeastern Pennsylvania (e.g. Shrewsbury Gas Filed, Lovelton Gas Field, Harvey’s Lake Gas Field), and there are numerous reports of gas shows between 80 and 800 feet during the drilling of oil and natural gas wells.”

The study also noted the region’s water wells are not constructed with proper engineering standards to keep unwanted contaminants out of the water they provide.  From the study:

The great majority of water wells in Susquehanna County penetrate the fractured Catskill Formation, in which groundwater flow in unweathered bedrock appears to be controlled by secondary permeability primarily through vertical to near vertical north-south oriented fractures.  Most of the bedrock water wells are unsealed open-hole completions with casing terminating in the shallow bedrock in order to draw water from multiple horizons…” (emphasis added)

So there you have it.  Methane in northeastern Pennsylvania groundwater is actually quite common due to the fact that the rock holding the region’s water aquifer is a hydrocarbon bearing resource, which itself is intersected by water wells that lack proper engineering standards.

The researchers also noted that methane in the region, while ubiquitous, tends to reach its greatest concentration in valleys:

“[A]lthough valley wells represent only 51% of the total water well population, they comprise 88% of the water wells with methane concentrations that exceed 7000 μg/L.”

This was the case regardless of whether or not shale development had taken place in close proximity:

“Furthermore, methane concentrations in valley water wells in gas production areas (i.e., located within 1 km of an active gas well) versus valley water wells in nonproduction areas (i.e., greater than 1 km from a gas well) show no statistical difference, indicating that the regional presence of elevated methane concentrations in valleys is a natural phenomenon. This is not an original finding, as the presence of elevated methane levels in valley water wells in the Appalachian basin has also been observed in a study in West Virginia by Mathis and White (2006), which found that methane concentrations from 170 water wells that exceeded 10,000 μg/L occurred in wells located in valleys and hillsides, as opposed to hill tops (Mathis and White 2006).”

Taking all of these items into consideration, the study noted: “the use of hydraulic fracturing for shale gas in northeastern Pennsylvania has not resulted in widespread gas migration into the shallow subsurface.”

Could these natural causes shed some light onto some of the highest profile claims of water contamination, such as Franklin Forks, where activists paraded celebrities around an otherwise quiet rural community to show them the “dangers” of hydraulic fracturing?

A review of topographical surveys (featured below) very clearly indicate that Franklin Forks is in a low lying region of Susquehanna County that is surrounded by three large geographical ridges.

Franklin Forks topographical map

Franklin Forks topographical map

When taken together with isotopic testing conducted by the Pennsylvania Department of Environmental Protection (DEP), it becomes rather clear that the methane in Franklin Forks is unrelated to shale development. As DEP noted in its release:

 “Salt Springs State Park, which historically contains naturally occurring methane… is approximately one mile from the affected homes. The testing determined that the water samples taken from the private water wells contained gas of similar isotopic makeup to the gas in the water samples taken from Salt Springs State Park. Additionally, the water wells and spring exhibited similar water chemistry…DEP’s testing also determined that the gas in the water samples taken from the private water wells was not of the same origin as the natural gas in the nearby gas wells.”

The upshot:  An extensive scientific investigation shows us that methane in northeastern Pennsylvania’s groundwater, as in so many other places, has no connection to shale development.


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