Post-conventional drilling, pre-unconventional “baseline” methane in NY and UK groundwater wells

Groundwater is safe in potential N.Y. fracking area by Blaine Friedlander, July 29, 2014, Cornell Chronicle
Two Cornell hydrologists have completed a thorough groundwater examination of drinking water in a potential hydraulic fracturing area in New York’s Southern Tier. They determined that drinking water in potable wells near conventional natural gas wells in Chenango County is safe to drink and within federal guidelines. The researchers report their findings in July’s Journal of Hydrology – Regional Studies.

“In Pennsylvania, reports of natural gas in the groundwater started to occur after the state began to allow hydraulic fracturing. Nobody had thought to test the well water there beforehand [Or was it intentional by elected officials, regulators and industry, to make it more difficult for water wells owners with dangerous methane contamination to file lawsuits as appears to have been the case in numerous states and provinces?], and no one had a sense of the water quality prior to fracking. We’ve conducted a comprehensive baseline study of the water,” said Todd Walter, associate professor of biological and environmental engineering, the paper’s senior author.

“We’re verifying that the water quality here [in the Southern Tier] is pretty good,” said lead author Lauren McPhillips, doctoral candidate in the field of biological and environmental engineering. “There is some naturally occurring methane caused by geology – and not by humans – but none of the concentrations we found hit levels considered dangerous,” she said.

The researchers studied more than 100 groundwater wells in Chenango County, a rural area with conventional natural gas wells. They sought to accurately assess any potential contamination in groundwater wells located both close and afar from a conventional gas well. [What about stratigraphic test holes, suspended and abandoned wells?  Why not include them?]

“With the potential for unconventional technology (high-volume, hydraulic fracturing of horizontal wells) being used to access Marcellus Shale gas resources in New York state, it is important to gather baseline information on water quality before this contentious technology is implemented,” the researchers wrote.

In Chenango County, methane concentrations – attributable to natural geological processes – were higher in groundwater dominated by sodium chloride or sodium bicarbonate, when compared with groundwater dominated by calcium bicarbonate. This indicates that groundwater interacts with bedrock and is staying below ground for a longer period.

In nearby Pennsylvania, which allows hydraulic fracturing, one research group led by Robert Jackson of Duke University found higher groundwater methane concentrations and “thermogenic isotope signatures” (chemical fingerprints caused by deep, natural processes in the Earth) near existing gas wells, but no correlation to other factors.

Another study led by Lisa Molofsky of GSI Environmental Inc. in Houston found no relationship between dissolved methane in groundwater and proximity to gas wells, but did find methane concentrations were higher in valleys and in groundwater dominated by sodium chloride or sodium bicarbonate.

Other co-authors of the paper, “Assessing Dissolved Methane Patterns in Central New York Groundwater,” are Anne Elise Creamer ’13 and Brian G. Rahm, postdoctoral researcher with Cornell’s New York State Water Resources Institute. Research funding was provided by Cornell’s Atkinson Center for a Sustainable Future, the New York Water Resources Institute and the Cornell Engineering Learning Initiative Program. [Emphasis added]

National Methane Baseline Survey of UK groundwaters by British Geological Survey

Methane occurs naturally in the atmosphere and is commonly found at trace levels as a dissolved component of groundwater. Methane is also released by human activity and is an important greenhouse gas.

We are surveying the current distribution of methane concentrations in UK groundwater, focussing on areas where aquifers are underlain by shale units that may be exploited for shale gas. The National Methane Baseline dataset will be a reference point against which any future changes in groundwater methane concentrations can be measured.

The UK need for methane baseline data

Understanding the current distribution of methane in UK groundwaters will provide a baseline against which any future changes can be measured. This has become particularly important with increasing interest in shale gas in the UK.

Evidence from the USA has shown very high methane concentrations in some aquifers in some areas where shales are being commercially exploited for gas. However, there is considerable uncertainty and argument over the source(s) of methane and how it has entered the aquifers.

Crucially, there are no consistent baseline data on methane concentrations in groundwater in the USA collected before shale gas exploitation began, which makes it very difficult to assess and deal with the observed problems of methane in groundwater.

The need for a methane baseline in the UK was recognised in the 2012 report on shale gas extraction published by the Royal Society and Royal Academy of Engineering 7.9 MB pdf.

In the UK, BGS scientists are building on our previous work and measuring methane concentrations in groundwater in a range of aquifers before any shale gas development gets underway. This will provide a baseline against which any future environmental changes can be assessed, and will enable informed management decisions to be taken.

The methane baseline is therefore defined for this project as the current background range of methane concentrations in UK groundwaters before any significant exploitation of unconventional hydrocarbons, such as shale gas, takes place.

The measured methane may not necessarily originate naturally from geological sources — in some cases it may have been produced or released because of human activities such as coal mining or landfill operations.

Collecting groundwater samples for methane analysis is straightforward, providing certain precautions are undertaken.

To get an accurate concentration measurement, groundwater has to be sampled before it comes into contact with air so that no gas can escape. This means collecting a sample directly from a pumped borehole, by attaching a hose with an airtight connection at the top of the borehole before the pumped water enters a storage tank or is treated in any way. [Alberta Environment, companies and the AER did not do this for any of the water contamination cases in Alberta]

Special containers are used to preserve the sample until it reaches the laboratory. In addition to sampling for dissolved methane, a number of chemical parameters are measured in the field (eg groundwater temperature, dissolved oxygen and redox potential) and samples are collected for laboratory analysis of a broader range of chemical parameters.

Other web pages provide further information on the UK baseline groundwater chemistry programme.

To find suitable boreholes, BGS greatly appreciates the support provided by the Environment Agency, Natural Resources Wales, water utilities and other private borehole owners such as farms and golf courses.

Summary results from the survey (up to April 2014) and summary of existing data.

Methane data from previous BGS water quality surveys have been published in papers and reports that are available from the BGS website. The references are given below. Please note that a small amount of data from these published sources has not been used in the statistical summaries for the regions presented in the accompanying web pages because they were considered not to represent typical baseline conditions. [Emphasis added]

Gooddy, D, and Darling, W G.  2005.  The potential for methane emissions from groundwaters of the UK.  Science of the Total Environment, 339. 117–126.

Darling, W G, and Gooddy, D C.  2006.  The hydrogeochemistry of methane : evidence from English groundwaters.  Chemical Geology, 229 (4). 293–312.

Ó Dochartaigh, B E, Smedley, P L, MacDonald, A M, Darling, W G, and Homoncik, S.  2011.  Baseline Scotland: groundwater chemistry of the Carboniferous sedimentary aquifers of the Midland Valley.  British Geological Survey Open Report OR/11/021. 91pp.

Contact Dr George Darling for further information.

[Refer also to:

2012: Dissolved methane in New York groundwater, 1999—2011: U.S. Geological Survey Open-File Report 2012-1162, 6 p.

2013: Brief review of threats to Canada’s groundwater from the oil and gas industry’s methane migration and hydraulic fracturing by Ernst Environmental Service

A 2004 New York State Oil, Gas and Mineral Resources report states:

Most of the wells date before New York established a regulatory program. Many were never properly plugged or were plugged using older techniques that may not last. Abandoned wells can leak oil, gas and/or brine; underground leaks may go undiscovered for years. These substances can contaminate ground and surface water, kill vegetation and cause safety and health problems.

Historically, abandoned wells have been discovered in residential yards, playgrounds, parking lots, wooded areas, inside buildings and underwater in wetlands, creeks and ponds. Every year DEC staff discover additional abandoned wells while conducting scheduled inspections or investigating complaints. Many abandoned well issues take several years to resolve as  [the Department of Environmental Conservation (DEC)] pursues legal action against the responsible parties. [Emphasis added]

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