Marcellus natural gas trend
Chief Oil and Gas
|Start of production||2000s|
|Current production of gas||15,000×106 cu ft/d (420×106 m3/d)|
|Year of current production of gas||2014|
|Estimated gas in place||168,000×109 cu ft (4,800×109 m3)|
|Producing formations||Marcellus Formation|
The Marcellus natural gas trend is a large and prolific area of shale gas extraction from the Marcellus Formation of Devonian age in the eastern United States. The trend encompasses 104,000 square miles and stretches across Pennsylvania and West Virginia, and into southeast Ohio and upstate New York. It is the largest source of natural gas in the United States, and production was still growing rapidly in 2013. The natural gas is trapped in low-permeability shale, and requires the well completion method of hydraulic fracturing to allow the gas to flow to the well bore. The surge in drilling activity in the Marcellus Shale since 2008 has generated both economic benefits and considerable controversy.
Although before 2008 the Marcellus Shale was considered to have inconsequential natural gas potential, it is now believed to hold the largest volume of recoverable natural gas resource in the United States. In 2012, it was estimated to have 141 trillion cubic feet of technically recoverable gas by the US Energy Information Administration, and 88 trillion cubic feet by the US Geological Survey. In September 2012, the Marcellus Shale overtook the Haynesville Shale of northwest Louisiana as the leading producer of both shale gas and overall natural gas in the United States. In February 2014, Marcellus gas wells produced 14.0 billion cubic feet per day, a 42 percent increase over the year previous, and comprising 21 percent of all the dry gas produced that month in the United States.
The impervious limestone layers of the Onondaga directly below the Marcellus, and the Tully Limestone at the top of the Hamilton Group, have trapped valuable natural gas reserves in this formation. The gas is produced by thermogenic decomposition of organic materials in the sediments under the high temperature and pressure generated after the formation was buried deep below the surface of the earth. The rock holds most of the gas in the pore spaces of the shale, with vertical fractures or joints providing additional storage as well as pathways for the gas to flow; gas is also adsorbed on mineral grains, and the carbon in the shale.
The industry was long aware there was gas in the Marcellus, but it "occurred in 'pockets' and flows could not be sustained". These gas flows died down quickly, and the drillers soon began to ignore them when they encountered them...the consensus was that there was not enough to make a well." Before 2000, some low production gas wells were completed to the Marcellus, but these had a low rate of return, requiring a relatively long capital recovery period, although they did have a very long productive life. There are wells in Tioga and Broome County, New York which are 50 years old or more.
From 1976 to 1992, the U.S. Department of Energy funded the Eastern Gas Shales Project, which studied many eastern shale formations. The project drilled and cored five wells in the Marcellus in Pennsylvania. The cores established that there were enormous amounts of gas in the Marcellus, and defined fracture directions that were used in later Marcellus well drilling. Although the great volumes of trapped gas found by the project in the Marcellus and other eastern shales created excitement, the project was less successful at finding ways to recover the gas economically, especially at the low gas prices of the 1980s. "The furor over the Devonian shales faded during the early 1980s due to low gas prices and lack of sufficiently useful technologies for extracting the gas."
Range Resources drilled an unsuccessful well to the Oriskany Sandstone in 2003. Hoping to save some value by finding producible gas in the shallower formations in the wellbore, Range geologists noted that the Marcellus Formation had some of the same properties as the Barnett Shale of North Texas, which was a prolific source of gas. In late 2004 Range completed the well in the Marcellus, using hydraulic fracturing techniques developed for the Barnett, and started producing the well in 2005.
Range Resources was the first company to voluntarily disclose (2010) the chemicals used at each of their fracking sites. Early experiments in Mount Pleasant Township, 30 miles southwest of Pittsburgh led to lengthy legal battles over pollution of well water and air and the industrialization of residential areas involving one of the "first sites ever drilled in the Marcellus shale" where "three of the wells... were experimental (Lavelle 2010-10-22). Range Resources spokesperson claimed that "more than 2,100 Marcellus wells" had been drilled in Pennsylvania by 2010 and at that time of there were "thousands of landowners across the state who have signed leases allowing gas companies to produce on or under their properties" who had not complained and "numerous happy landowners among the hundreds of Range leaseholders in Washington County"  enjoying the economic benefits of leasing mineral rights on their properties. In 2013, Range allowed the two small children of the Hallowich family to talk about the Marcellus Formation.
By 2008 the Marcellus Formation had become the focus of shale gas development, starting in Pennsylvania. Only four Marcellus wells were drilled in Pennsylvania in 2005; in 2010 1,446 Marcellus wells were drilled in Pennsylvania. Leasing agents aggressively sought out acreages to lease mineral rights. The price for leasing rose from $US300 per acre in February to $2,100 in April, 2008.
To extract the shale gas at more commercially viable rates, directional drilling is done to depths of 7,000 to 10,000 ft (2,100 to 3,000 m) underground to reach the formation, and then water and a mixture of chemicals is pumped into the rock under high pressure in a process known as hydraulic fracturing to release the gas from the low permeability shale.
Several companies have carried their experience tapping the Barnett Shale of Texas into the Marcellus trend. The Marcellus covers several times more area, stretching 600 miles (970 km), compared to a linear extent of only 170 miles (270 km) for the Barnett.
As of 2008, only a few new Marcellus wells were actually in operation, with at least one reported to be producing more than 3 million cubic feet (85 thousand m³) per day. Engelder, who has studied natural rock fractures in this area for more than 25 years, noted that drilling horizontally through the Marcellus shale perpendicular to the vertical fractures better connected the natural pathways for gas flow. Early results show that horizontal wells in this formation are producing gas at a rate more than double that of vertical wells, and at slightly lower cost overall, despite the much higher initial cost of drilling.
Since parts of this region have been producing gas from wells drilled to the deeper Oriskany Formation sandstone, older wells that are no longer viable can be reused, either by fracturing the Marcellus layer in the existing well bore, or by refinishing the bore using horizontal drilling into the Marcellus. Re-use of the existing infrastructure has both environmental as well as economic benefits, because in addition to avoiding development of new drilling sites and wells, existing transportation facilities can be reused.
Researchers at the University of Pittsburgh recently released a study showing that "7 percent of Allegheny County's land has been leased for drilling and extraction since 2003" and the number of properties in the county leased for oil and gas exploration has grown exponentially in recent years.
Mergers and acquisitions
Royal Dutch Shell's $4.7 billion acquisition of East Resources in 2010, with acreage in four Marcellus states, stood out amongst a flurry of acquisitions, and by the end of the year National Geographic's special report on the developments was titled "The Great Shale Gas Rush."
Planning for infrastructure projects was reported in West Virginia, Pennsylvania, and Ohio to accommodate the growth during this period, including for pipeline and water treatment services.
Several pipeline projects completed in 2013 carry Marcellus gas to New York and New Jersey, and were expected to result in lower gas prices to consumers in those areas. A pipeline to carry Marcellus to New England, where consumer natural gas prices are higher, is not expected to be in service until 2016.
In August 2010, Kinder Morgan announced plans to construct a 230-240 mile-long underground pipeline, which would transport recovered natural gas supplies in Western Pennsylvania from West Virginia to Toledo, ultimately connecting with existing pipelines in Michigan and Southern Ontario. In September, Warren, Ohio's water treatment facility announced plans to become the first in the state to accept waste water from shale drilling, while at the 2010 Marcellus Summit in State College, Pennsylvania, state officials announced they were working with local officials on bonding issues for new infrastructure.
Laurel Mountain Midstream announced in October plans to expand its pipeline collection system, and later that month Texas-based El Paso Midstream Group and Spectra Energy signed a memorandum of understanding to construct their Marcellus Ethane Pipeline System to connect existing Ohio and Pennsylvania pipelines with Gulf Coast destinations.
The Atlantic Coast Pipeline is a 600 miles (970 km) pipeline that is planned to enter service in 2019 and will draw gas from the Marcellus formation in West Virginia and run south to North Carolina.
Estimates of recoverable natural gas in the Marcellus have, and still do, vary greatly. The first to come forward with a substantial number was Pennsylvania State University geosciences professor Terry Engelder, who announced his startling calculation of natural gas in 2008.
Estimated recoverable gas
- 2002, United States Geological Survey: 1.9 trillion cubic feet (TCF) undiscovered, technically recoverable natural gas
- 2008, Terry Engelder,: 363 trillion cubic feet (10.3 trillion cubic metres) of recoverable natural gas
- 2008, State University of New York at Fredonia geology professor Gary G. Lash: 49 TCF recoverable
- 2009, United States Department of Energy: 262 TCF of recoverable gas.
- 2011 United States Geological Survey: 84 TCF.
- 2011, US Energy Information Administration: 410 trillion cubic feet technically recoverable gas
- 2012, US Energy Information Administration: 141 trillion cubic feet technically recoverable gas
- 2010, US Energy Information Administration: 13.2 trillion cubic feet of gas
- 2011, US Energy Information Administration: 31.9 trillion cubic feet of gas
- 2012, US Energy Information Administration: 42.8 trillion cubic feet of gas
According to the Financial Post, the boom in US shale oil production, using horizontal drilling and hydraulic fracturing, created thousands of jobs and reduced United States dependence on imported gas.
During the 2012 presidential campaign, GOP Primary Candidate Rick Perry cited a study funded by the Marcellus Shale Coalition that fracking the Marcellus Formation is expected to create a quarter million jobs under the current policies of the Obama administration.
The number of permits issued by Pennsylvania tripled between 2008–2009, including $3.5 billion in land acquisitions. An industry-sponsored study (pdf) by Pennsylvania State University estimates there will be 200,000 new jobs in Pennsylvania by 2020 if shale is developed to its full potential, however since 2007 the natural gas companies have been hiring experienced crews from Texas and Oklahoma for the high-paying work on drilling rigs that operate 24 hours a day, seven days a week.
West Virginia's economy grew $1.3 billion in 2009 as a result of the rush.
In 2010, Range Resources' Marcellus Shale Division reported producing 200 million cubic feet (5.7 million cubic metres) of gas, anticipating the figure to double in 2011. The Marcellus Shale Coalition has predicted 88,000 new employment positions in 2011 as a result of the rush.
By the end of that year, it was reported that more drilling rigs were moving into Ohio, where the shale is more shallow. Chesapeake Energy was cited as making "big plans" for development in the state in 2011, as rural reports from West Virginia indicated the infrastructure was overwhelmed by the growth.
A June 2011 New York Times investigation of industrial emails and internal documents found that the financial benefits of unconventional shale gas extraction may be less than previously thought, due to companies intentionally overstating the productivity of their wells and the size of their reserves.
Marcellus gas production has lowered the price of natural gas in the Mid-Atlantic states of the US, which previously were almost entirely dependent on gas pipelined in from the US Gulf Coast. From 2005 through 2008, wholesale gas prices at Mid-Atlantic states were $0.23 to $0.33 per million BTU above prices of the main Gulf Coast trading point, the Henry Hub. The US Energy Information Administration reported in 2012 that Marcellus production had lowered regional gas prices to nearly par with Henry Hub, and projected that by 2015, Marcellus gas would drive gas prices in its area down to $0.10 below Henry Hub. In October 2013, the US EIA reported that futures markets were predicting Appalachian gas prices to dip to $0.30 below Henry Hub in 2016.
Drilling slowed in 2012 when gas prices dropped but the Nature Conservancy predicts that up to 60,000 wells will be drilled in Pennsylvania by 2030.
The environmental impacts of tapping the Marcellus Shale are hotly debated. The effects of horizontal drilling and hydraulic fracturing on the surface water, groundwater, the chemicals used in fracturing, the disposal of toxic fracturing fluid, air pollution, drilling safety, spills, forest fragmentation, encroachment on residential communities, road use, and land reclamation are all contentious issues.
Heavy trucks and tanker trucks can cause expensive road damage such as cracked pavement and potholes on roads not rated for heavy traffic. Engineers in the Pennsylvania Department of Transportation have documented damage caused by the heavy trucks and tankers. Damage includes crushing of drain pipes, potholes, rutting, and pavement fatigue failure. The cost of these repairs are often much higher than the Pennsylvania Department of Transportation is allowed to charge for road use. In addition to causing road damage, when heavy trucks and tankers drive over farmland, they compact the subsoil, which increases runoff and decreases crop productivity for years. Ecologists also have concerns about the ecological impact on forests when trees are cut down to make way for access roads. Ornithologists have documented declining populations of woodland birds.
The massive hydraulic fracturing in the Marcellus uses three to five million gallons of water per well, usually taken from surface water. In Pennsylvania, withdrawals for Marcellus fracking make up 0.2% of the total water use statewide.
The Susquehanna River Basin Commission, which oversees this other portion of the watershed, and the Pennsylvania Department of Environmental Protection, issued orders to suspend operations at several wells in May 2008 because surface water was being diverted by the drillers without the necessary permits, and precautions to protect streams from contaminated runoff were questioned. The practices of "land men" who acquire leases for drilling and extraction rights have also been widely questioned.
A large portion of the formation underlies the environmentally sensitive Chesapeake Bay Watershed as well as the Delaware River Basin. The Delaware River Basin Commission, which holds regulatory jurisdiction over water usage, extraction, or potential contamination, has made a "determination" that requires that any component of a hydro-fracking operation within the boundaries of their Special Protection Waters must be permitted by the DRBC, regardless of whether or not the operation was previously subject to permitting.
Faced with opposition to hydraulic fracturing in the New York City watershed area, Chesapeake Energy made a no-drilling pledge for five miles around the watershed; but the company opposed any legislation like that presented by Jim Brennan (D-Brooklyn), October 2009.
The Pennsylvania Department of Environmental Protection concluded that Marcellus gas wells caused dissolved methane to contaminate up to 15 domestic water wells in Dimock Township, Susquehanna County, Pennsylvania. This conclusion is disputed by Cabot Oil & Gas Corp., which was cited for causing the contamination. It is also disputed by other long-term area residents who noted that high methane levels had been present for more than 60 years prior to hydrofracking in Dimock. Northeast Pennsylvania is not the only place to experience groundwater contamination allegedly following Marcellus gas drilling operations.
Some pro-industry figures have stated that while gas drilling and production are generally safe, anti-gas views in the Marcellus trend have been increased by the industry's early mistakes and unwillingness to be open with the public. Marcellus proponent Terry Engler noted that at the start of the Marcellus boom, Pennsylvania well construction regulations, particularly for cementing, "were just inadequate to the task" of protecting groundwater; they have since been strengthened. Former Shell Oil president John Hofmeister said that the industry should not pretend that it is perfect, for while the vast majority of gas wells do not affect ground water, "everybody knows that some wells go bad." 
Pennsylvania state law sets a "rebuttable presumption" for contamination occurring in water supply wells near oil and gas wells, meaning that the law automatically holds oil and gas operators responsible for contamination in nearby water wells, unless the companies can demonstrate that they were not responsible. The new Pennsylvania oil and gas law passed in February 2012 increased the rebuttable presumption distance around each oil and gas well, from 1,000 feet to 2,500 feet, and increased the time period from 6 months to one year following drilling, completion, or alteration of a well bore.
Ronald E. Bishop, a lecturer in chemistry and biochemistry at the State University of New York, Oneonta, estimates based on a non-peer-reviewed study, that nearly 2% of gas wells may end up polluting groundwater with fracking fluids[not in citation given] In northeastern Pennsylvania and New York a study of 68 private drinking wells, which included the Dimrock Township site, the methane concentration was high in close proximity to the natural gas drilling and hydraulic fracturing. The average was within the defined action level of less than 28 mg/L and greater than 10 mg/L for hazard moderation which is recommended by the U.S. Department of the Interior but the maximum of 64 mg/L was above that threshold. The study found no evidence of contamination by Marcellus saline brines or by hydraulic fracturing fluid. John Hanger, former head of the Pennsylvania DEP, blamed the methane contamination on poor well construction, though he could not rule out fracking as the cause.
Youngstown, Ohio experienced a 4.0-magnitude earthquake on December 31, 2011, the area's 11th earthquake in 10 months. Experts believe that these were induced seismicity triggered by disposal of wastewater from Marcellus gas wells into Class II underground injection wells. The Ohio Department of Natural Resources explained their reasons for closing the Northstar 1 deep injection well, "one of 177 operational Class II deep injection wells which primarily dispose of oil and gas fluid waste deep underground using high pressure.(Ohio: Disposal Wells) Since March 2011, the Youngstown area "experienced 12 low-magnitude seismic events along a previously unknown fault line. These events ranged from 2.1- to 4.0-magnitude and were recorded by the Ohio Department of Natural Resources’ (ODNR) Ohio Seismic Network (OhioSeis).... The 2011 earthquakes are distinct from previous seismic activity in the region because of their proximity to a Class II deep injection well, known as the Northstar 1 well. In fact, all of the events were clustered less than a mile around the well."
- US Energy Information Administration, Annual energy outlook 2012.
- US Energy Information Administration, Natural Gas Weekly Update, 1 May 2014.
- Wynne, Peter (2008-03-20). "Gas-drilling misinformation causing unnecessary anxiety in Wayne County". The Weekly Almanac (Wayne County, PA).
- "Marcellus Shale Gas: New Research Results Surprise Geologists!". geology.com. Dr. Hobart M. King. Retrieved 2008-05-03.
- "Assessment of Geological Sequestration Potential in Pennsylvania" (PDF). Pennsylvania Department of Conservation and Natural Resources. 2006-09-18. Retrieved 2008-07-07.
- Harper, John A. (2008). "The Marcellus Shale - An Old "New" Gas Reservoir in Pennsylvania" (PDF). Pennsylvania Geology. Pennsylvania Bureau of Topographic and Geologic Survey. 38 (1).
- John A. Harper and Jaime Kostelnik, The Marcellus Shale play of Pennsylvania, Pennsylvania Geological Survey.
- Marianne Lavelle (October 17, 2010). "A Dream Dashed by the Rush on Gas". National Geographic News. The Great Shale Gas Rush. Retrieved February 2013. Check date values in:
- "Hallowich children not part of Marcellus Shale gag order agreement". Pittsburgh Post-Gazette. Retrieved 7 March 2015.
- Marcellus Shale Advisory Commission, Final Report, 2012, p.34.
- Clifford Krauss (April 8, 2008). "There’s Gas in Those Hills". New York Times.
- "Marcellus workforce training", WDUQ. 2 July 2010. Retrieved 13 July 2010.
- "Unconventional natural gas reservoir could boost U.S. supply". Penn State Live. Pennsylvania State University. 2008-01-17. Retrieved 2008-04-04.[permanent dead link]
- Gebhart, Rob (2001-08-12). "Texas company to search for gas in Somerset County". Daily American. Archived from the original on 2013-08-27. Retrieved 2008-04-02.
- Basim Faraj and James Duggan (2007). "Devonian Aged Shale Gas Potential of the Southern Tier of New York". 2007 AAPG Annual Meeting, Long Beach California. American Association of Petroleum Geologists.
- Chernoff, Harry (2008-03-17). "Investing in the Marcellus Shale". Seeking Alpha. Retrieved 2008-04-06.
- Durham, Louise S. (March 2008). "Appalachian Basin's Marcellus – the new target : Another Shale Making Seismic Waves". AAPG Explorer. American Association of Petroleum Geologists. Retrieved 2008-04-06.
- Gold, Russell (2008-04-02). "Gas Producers Rush to Pennsylvania : Promising Results There Spur Investment". The Wall Street Journal. p. A2.
- "Pitt Database of Oil and Gas Leases Gauges Marcellus Shale Activity in Allegheny County Since 2003, Shows Leases Up 322 Percent in 2009". University of Pittsburgh. August 16, 2010. Retrieved 9 October 2012.
- "Chesapeake announces joint venture agreement", World Oil, December 2008, p.106.
- "Royal Dutch Shell plc acquires new positions in US tight gas", Royal Dutch Shell. May 28, 2010. Accessed December 18, 2010
- "Royal Dutch Shell buys Marshall gas driller East Resources Inc. for $4.7b", Rick Stouffer. Pittsburgh Tribune. May 29, 2010. Accessed December 18, 2010
- “Natural gas drilling water treatment plant planned”, iStock News. June 17, 2010. Accessed December 18, 2010
- “Penn. natgas water treatment plant challenged”, Reuters. November 3, 2009. Accessed December 18, 2010
- “Pipelines expanding to move Marcellus shale gas”, Pipeline and Gas Technology. September 1, 2009. Accessed December 18, 2010
- “Kinder Morgan Building New Marcellus Shale Pipeline from Pennsylvania to Michigan”, Marcellus Drilling News. April 2010. Accessed December 18, 2010
- “Warren Treatment Plant Gets OK to Process Wastewater from Marcellus Drilling”, The Business Journal. December 7, 2010. Accessed December 18, 2010
- US Energy Information Administration, Marcellus natural gas pipeline projects to primarily benefit New York and New Jersey, 30 Oct. 2013.
- "New pipeline could impact Muskingum, Coshocton counties", Brian Gadd. Zanesville Times Recorder. 23 aug 2010. Retrieved 5 sept 2010.
- "Local News - Coshocton Tribune - coshoctontribune.com". Coshocton Tribune. Retrieved 7 March 2015.
- "Speakers say road work emerging issue in Marcellus development". ogj.com. Retrieved 7 March 2015.
- "PennEnergy - Energy News & Market Research Covering Oil and Gas, Power Generation and Renewable Energy". pennenergy.com. Retrieved 7 March 2015.
- El Paso and Spectra Energy announce execution of MOU to jointly develop MEPS
- "Atlantic Coast Pipeline hires main construction contractor". Oil and Gas Journal. September 22, 2016. Retrieved February 7, 2017.
- Esch, Mary (2008-11-04). "Estimated gas yield from Marcellus shale goes up". Philly.com.[dead link]
- "Got gas, lots". Pittsburgh Tribune-Review. 2008-11-05.
- Bertola, David (2008-02-08). "Researchers: Shale holds vast supply of natural gas". Business First of Buffalo. Retrieved 2008-04-02.
- US Department of Energy (April 2009): Modern shale gas development in the United States: a primer, p.17, PDF file, downloaded 11 June 2009.
- US EIA, U.S. crude oil and natural gas proved reserves, 1 Aug. 2013.
- US EIA, Proved reserves, principal shale plays.
- Ed Crooks; Ajay Makan (January 27, 2013). "Flares take shine off shale boom". Financial Post. New York and London. Retrieved February 2012. Check date values in:
- Farley, Robert. "Just the Fracking Facts." FactCheck.org, 14 October 2011.
- "The Marcellus Shale: New York is the Natural Gas Industry’s New Lab Rat", Allison Sickle. DC Bureau. December 4, 2009. Accessed December 18, 2010
- "Nat Gas Facts: New York", Independent Oil and Gas Association of New York. Accessed December 18, 2010
- "State-issued Marcellus Shale gas well drilling permits increase 300% in 2009", Ford Turner. The Patriot News. November 4, 2009. Accessed December 18, 2010
- "A Drive for New Jobs Through Energy", National Geographic. October 14, 2010. Accessed December 18, 2010
- "Gas Drilling Booms in Valley", Casey Junkins. The Intelligencer. December 25, 2010. Accessed January 6, 2011
- "Shale drillers anticipate creating more jobs", Candy Woodall. Pittsburgh Post-Gazette. December 16, 2010. Accessed January 6, 2011
- "Marcellus Shale 2010: The year the gas boom came to the region", Kristy Foster. Farm and Dairy. December 29, 2010. Accessed January 6, 2010
- "Marcellus Shale looks to be major player for natural gas", Newark Advocate. January 6, 2011. Accessed January 6, 2011
- "Business Tri-State: Ohio gov.-elect eyes gas riches of Marcellus Shale", Herald Dispatch. December 31, 2010. Accessed January 6, 2010
- "Rush to tap gas fields clogs W.Va.'s country roads", West Virginia Gazette. December 10, 2010. Accessed December 18, 2010
- Urbina, Ian (25 June 2011). "Insiders Sound an Alarm Amid a Natural Gas Rush". New York Times. Retrieved 28 June 2011.; Urbina, Ian (27 June 2011). "S.E.C. Shift Leads to Worries of Overestimation of Reserves". New York Times. Retrieved 28 June 2011.
- US EIA, Marcellus natural gas production, 24 July 2012.
- US EIA, Markets expect Marcellus growth to drive Appalachian natural gas prices below Henry Hub, 9 Oct. 2013.
- Holzman, David. "Methane Found in Well Water Near Fracking Sites". Retrieved 7 October 2013.
- Waples, David A. The Natural Gas Industry in Appalachia, (2012): p.247.
- "Marcellus Shale". Catskill Mountainkeeper. Retrieved 2008-06-09.
- "Marcellus Shale Natural Gas: Environmental Impact" (PDF). The League of Women Voters of Pennsylvania.
- Governor's Marcellus Shale Advisory Commission, Report, 22 July 2011.
- Thompson, David (2008-05-31). "Gas Drilling : Companies told to stop operations". Williamsport SunGazette. Retrieved 2008-06-09.
- Engelder, Terry (2008-03-30). "Sunday Forum: Full of gas". Post Gazette. Retrieved 2008-06-09.
- Swarthmore College :: Environmental Studies Capstone :: Natural Gas Drilling in the Marcellus Shale Uncovered: Community, Environment, and Law
- csebestyen. "Delaware River Basin Commission-Page Not Found". state.nj.us. Retrieved 7 March 2015.
- Sabrina Shankman. "Does Chesapeake’s No-Drilling Pledge Do Enough to Protect NYC’s Watershed?". ProPublica. Retrieved 7 March 2015.
- "The New York City fuel gas code" (PDF). Retrieved 9 October 2012.[unreliable source?]
- "Ordinance supplementing the Pittsburgh Code, Title Six, Conduct, Article 1 Regulated Rights and actions, by adding Chapter 618 entitled Marcellus Shale Natural Gas Drilling". Retrieved 9 October 2012.
- "Resident affidavits regarding methane in Dimock wells" (PDF). Cabot Oil & Gas. 2010-07-20.
- "Gas Cabinets". The Times Leader. 2009-03-16.
- Kevin Begos, Associated Press, "Some say industry arrogance fueled fracking anger," Deseret News, 28 July 2013.
- JD Supra, New Pennsylvania oil and gas law, Feb. 2012.
- Pacchioli, David. "Grad researcher studies impacts of Marcellus Shale development on wildlife.". Retrieved 7 October 2013.
- Stephen G. Osborn, Avner Vengosh, Nathaniel R. Warner, and Robert B. Jacksona, Methane contamination of drinking water accompanying gas-well drilling and hydraulic fracturing. Proceedings of the National Academy of Sciences USA, 17 May 2011, v.108 n.20 p.8172–8176.
- "4.0 Magnitude Earthquake Strikes Near Youngstown". WBNS-10TV Columbus, Ohio. Retrieved 7 March 2015.
- ODNR Updates Ohio Earthquake Map to Reflect Statewide Seismic Activity Since 2002 (news release), Ohio Department of Natural Resources, Division of Geological Survey (September 18, 2007)
- "Youngstown Rocks: Is Fracking Causing Earthquakes in Ohio?". The Daily Beast. Retrieved 7 March 2015.
- "Ohio earthquakes linked to deep injection of Marcellus Shale drilling waste". PennLive.com. Retrieved 7 March 2015.
- Jason Hutt; Michael Weller (July 12, 2012). "Ohio Issues Emergency Rules on Underground Injection Control Activities, Effective Immediately". Bracewell & Giuliani, Energy Legal Blog.
- Preliminary Report on the Northstar 1 Class II Injection Well in the Seismic Events in the Youngston, Ohio, Area (PDF) (Report). Ohio Department of Natural Resources. March 2012. Retrieved February 2013. Check date values in: