Prepared in cooperation with the New York State Department of Environmental Conservation

Dissolved Methane in New York Groundwater

New York State is underlain by numerous bedrock 

formations of Cambrian to Devonian age that produce 

natural gas and to a lesser extent oil. The first commercial 

gas well in the United States was dug in the early 1820s 

in Fredonia, south of Buffalo, New York, and produced 

methane from Devonian-age black shale. Methane 

naturally discharges to the land surface at some locations 

in New York. At Chestnut Ridge County Park in Erie 

County, just south of Buffalo, N.Y., several surface seeps 

of natural gas occur from Devonian black shale, including 

one behind a waterfall (fig. 1). Methane occurs locally 

in the groundwater of New York; as a result, it may be 

present in drinking-water wells, in the water produced 

from those wells, and in the associated water-supply 

systems (Eltschlager and others, 2001).

The natural gas in low-permeability bedrock 

formations has not been accessible by traditional 

extraction techniques, which have been used to tap more 

permeable sandstone and carbonate bedrock reservoirs. 

However, newly developed techniques involving 

horizontal drilling and high-volume hydraulic fracturing 

have made it possible to extract previously inaccessible 

natural gas from low-permeability bedrock such as 

the Marcellus and Utica Shales. The use of hydraulic 

fracturing to release natural gas from these shale 

formations has raised concerns with water-well owners 

and water-resource managers across the Marcellus 

and Utica Shale region (West Virginia, Pennsylvania, 

New York and parts of several other adjoining States). 

Molofsky and others (2011) documented the widespread 

natural occurrence of methane in drinking-water wells 

in Susquehanna County, Pennsylvania. In the same 

county, Osborn and others (2011) identified elevated 

methane concentrations in selected drinking-water wells 

in the vicinity of Marcellus gas-development activities, 

although pre-development samples were not available for 

comparison. In order to manage water resources in areas 

of gas-well drilling and hydraulic fracturing in New York, 

the natural occurrence of methane in the State’s aquifers 

needs to be documented. This brief report presents a 

compilation of data on dissolved methane concentrations 

in the groundwater of New York available from the U.S. 

Geological Survey (USGS) National Water Information 

System (NWIS) (http://waterdata.usgs.gov/nwis).

Methane

Methane originates from several different sources. 

Biogenic methane is produced through biologic decomposition 

of organic matter at shallow depths and low temperatures in 

places such as swamps or landfills, or within glacial deposits 

that have decomposing organic matter—often termed ”drift 

gas.” Thermogenic methane is produced from organic matter 

buried millions of years ago, which has undergone physical 

and chemical changes at great temperature and pressure; other 

hydrocarbons such as ethane, propane, and butane, or oil also 

can be produced thermogenically.

Methane is a colorless, odorless, tasteless gas that can be 

flammable or explosive. It can trigger an explosion in enclosed/

confined spaces containing oxygen, coupled with an ignition 

source (an open flame or an electrical spark). Methane can act 

as an asphyxiate by displacing air in structures and replacing 

oxygen in animal circulatory systems; burning methane also can 

produce other toxic gases such as carbon monoxide (Eltschlager 

and others, 2001).

Photograph by Matthew Conheady (www.nyfalls.com)

Figure 1. Gas flame from natural gas seep at Chestnut Ridge County Park, 

Eternal Flame Falls, Erie County, New York. 

U.S. Department of the Interior

U.S. Geological Survey

Open-File Report 2012–1162

August 2012
2

Historic Accounts of Natural 

Gas Springs in New York

Otisco Lake—Easternmost Finger Lake, Onondaga County, N.Y.

From the Skaneateles Historical Society’s Girl Scout 

Scrapbook, Skaneateles, N.Y., December, 1942.

“Troop 57 Does Out-Door Cooking in a New Way”

“We’ve heard of a lot of ways to do outdoor cooking 

but Troop 57 of Skaneateles certainly pulled a new 

one out of the bag recently. The girls hiked along 

Otisco Lake through Puddin’ Mill Gorge where they 

cooked their lunch with natural gas which came up 

through the creek bed.”

Oak Orchard Acid Springs—Northern Genesee County, N.Y.

From S.E. North, 1899, “History of Alabama, New 

York—from our county and its people a descriptive 

and biographical record of Genesee County New 

York” accessed August 2009 at: http://history.

raysplace.com/ny/alabama-ny.htm.

“Alabama Sour Springs” also called “Oak Orchard 

Acid Springs,” celebrated for their medicinal 

purposes, are located on road 7, in the southern part 

of the town, in the “swamp” on a little elevation two 

and a half to four feet above the surrounding surface, 

within a circle of 50 rods, and no two alike: eight in 

all have been discovered and analyzed, three of which 

are of an acid nature, one sulphur, one magnesia, 

one iron and one of a gaseous nature, affording gas 

enough to light 50 ordinary gas burners.”

In groundwater, methane can be dissolved or in a gaseous 

state. When methane is dissolved, it acts like the carbon dioxide 

gas used in carbonated beverages, where the gas is held within 

the fluid under the confining pressure of the sealed container. 

When the container is opened, pressure is reduced and some 

of the gas comes out of solution, which causes bubbling and 

fizzing in the beverage. In aquifers, methane may be confined 

by overlying fine-grained deposits or unfractured bedrock. 

Dissolved methane concentrations in confined aquifers can be 

much greater than the saturation concentration at atmospheric 

pressure. As groundwater enters a well at atmospheric pressure, 

the natural gas can be released from the water, which can cause 

a column of gas to form above the water surface in the well or 

be released within a pressure tank, at faucets inside a home, or 

in structures enclosing the well, where it can become flammable 

or explosive as a result (Eltschlager and others, 2001). 

Methane reaches saturation in water at 28 milligrams per 

liter (mg/L) at atmospheric pressure and becomes flammable 

in air at about 5 percent by volume (Eltschlager and others, 

2001). The Office of Surface Mining recommends that 

methane concentrations greater than 28 mg/L in well water 

should be addressed immediately by removing any potential 

ignition source and venting the gas away from confined spaces 

(Eltschlager and others, 2001). The Office of Surface Mining 

also recommends that methane concentrations ranging from 10 

to 28 mg/L in water (or 3 to 5 percent by volume in air) signify 

an action level where the situation should be closely monitored, 

and if the concentration increases, the area should be vented 

to prevent methane gas buildup. Concentrations of methane 

less than 10 mg/L in water (or 1 to 3 percent by volume in air) 

are not as great a concern, but the gas should be monitored to 

observe if the concentrations increase over time (Eltschlager 

and others, 2001). Homeowners should contact their local or 

New York State Health Department for further information 

about measuring and mitigating ”action level” methane 

concentrations (as previously defined) in their water wells or in 

their homes.

New York Bedrock and Natural Gas and 

Oil Stratigraphy

The stratigraphic column from Hill and others (2003) 

(fig. 2) shows that at least some natural gas has been developed 

from almost all the bedrock formations in New York State, 

indicating that bedrock units yielding some volume of methane 

are widespread. Therefore, any open borehole such as a water 

well, potentially could contain methane gas. Even though 

there are many gas-producing formations, relatively little data 

exist citing the occurrence, distribution, and concentration of 

methane in groundwater.

Dissolved Methane Concentration Data in New York

The collection of dissolved methane 

concentrations in groundwater by the 

USGS in New York coincided with 

groundwater age-dating applications for 

aquifer studies in the late 1990s. Various 

tracers can be used to date groundwater 

including tritium (Solomon and others, 

1993), chlorofluorocarbons (CFC) 

(Plummer and others, 2006), and sulfur 

hexafluoride (SF6) (Busenberg and 

Plummer, 2000). As part of the age-dating 

method, dissolved gas samples (nitrogen, argon, carbon dioxide, 

oxygen, and methane) are collected and analyzed to help 

determine the time when groundwater recharge occurred. When 

the age-dating results are reported, the supporting dissolved gas 

data (including methane) are sometimes included. Methane data 

from such previous age-dating studies (Komor, 2002; Yager and 

others, 2007) have been compiled for this report.

Since 2002, the USGS, in cooperation with New York 

State Department of Environmental Conservation (NYSDEC), 

has conducted groundwater-quality monitoring assessments 

in major river basins in New York (http://ny.water.usgs.gov/

projects/305b/). Since 2009, these assessments have included 

sampling for dissolved gases, including methane (Nystrom, 

2011, 2012, and Reddy and Risen, 2011). By 2011, methane 

had been sampled in 8 of the 14 major river basins in the State. 

These data, combined with those from groundwater age-dating 

analyses, yielded dissolved methane concentrations from water 

wells at 239 locations in New York from 1999 to 2011 (fig. 3).
3

Sh Shale

Ss Sandstone

Ls Limestone

Dol Dolostone

EXPLANATION

Lithology

cgl Conglomerate

gyp Gypsum

slt Siltstone

Primary bedrock Secondary bedrock

(From Hill and others, 2003)

Figure 2. Bedrock stratigraphic column for New York State, indicating time period, bedrock groups, unit names, lithology, 

average thickness, and if the unit could produce natural gas or oil.
4

EXPLANATION

Dissolved methane concentrations, in milligrams per liter

Non-detect (<0.001), Spring

Non-detect (<0.001), Bedrock

Non-detect (<0.001), Unconsolidated

0.001 to 1, Bedrock

0.001 to 1, Unconsolidated

1.01 to 10, Bedrock

1.01 to 10, Unconsolidated

10.1 to 28, Unknown

10.1 to 28, Bedrock

10.1 to 28, Unconsolidated

>28, Bedrock

>28, Unconsolidated

Marcellus and Utica shale outcrops

Other black and gray shale outcrops

Geologic age

Cretaceous and Cenozoic unconsolidated

Triassic

Devonian

Silurian

Upper and Middle Ordovician

Lower Ordovician and Upper Cambrian

Precambrian

80°00' 78°00' 76°00' 74°00' 72°00'

45°00'

44°00'

43°00'

42°00'

41°00'

0 30 60 90 MILES

0 30 60 90 KILOMETERS

Geologic ages modified from Schruben

and others, 1994: 1:2,500,00

Shale rock outcrops modified from Fisher

and others, 1970: 1:250,000

Base from U.S. Geological Survey digital data

Tompkins County area Onondaga 

County area Ulster County area

Bedrock geology

Figure 3. Location of wells and dissolved methane concentrations in New York groundwater, 1999–2011.
5

0

5

10

15

20

25

30

35

40

45

Non-detect - 113 samples

(47 percent)

>0.0 but <1.0 mg/L - 87 samples

(36 percent)

1.0 to 10.0 mg/L- 18 samples (8 percent) 

10.1 to 28.0 mg/L - 16 samples (7 percent)

>28.0 mg/L - 5 samples (2 percent)

Number of samples

Methane concentrations, in milligrams per liter (mg/L)

10 30 50 70 90 110 130 150 170 190 210 230

Figure 4. Histogram 

showing methane 

concentration by 

concentration range 

in groundwater in 

New York, 1999–2011.

Results

Samples collected through 2011 indicate that 

concentrations of methane in groundwater from most wells 

measured (91 percent of the wells) were at or below the 

Office of Surface Mining action level of 10 mg/L (Eltschlager 

and others, 2001), and a large number of wells (47 percent) 

had no detectable methane (fig. 4 and table 1). However, 

methane concentrations from several wells exceeded 10 mg/L 

(9 percent); in five cases, the measured concentrations were 

greater than 28 mg/L (2 percent). 

Methane was detected in both unconsolidated and bedrock 

aquifers across New York (table 1 and fig. 4). In unconsolidated 

aquifers, 93 percent of the wells had non-detect to low-level 

methane concentrations (methane concentrations <1 mg/L), 

and less than 1 percent of the wells (one well) was greater 

than the saturation value of 28 mg/L. The greater methane 

concentrations are most likely associated with confined glacial 

aquifers over black shale bedrock. In bedrock formation 

aquifers, 73 percent of the methane concentrations were 

less than 1 mg/L, while nearly 4 percent had concentrations 

greater than 28 mg/L across the State. Three of the four 

highest methane values in bedrock wells were associated with 

Devonian-aged black shale bedrock; in total, many of the 

greater methane concentrations were most likely associated with 

wells drilled into these shales (fig. 3). 

The 1999–2011 analysis of dissolved methane in 

groundwater in New York is meant to document the natural 

occurrence of methane in the States aquifers. The data 

describing the occurrence of methane come from a limited 

dataset collected for general groundwater quality under the 

305B program or were associated with the age-dating of 

groundwater. While many of the greater concentrations of 

dissolved methane appear to be associated with wells drilled 

in black shale bedrock or in unconsolidated deposits overlying 

black shale bedrock, the limited set of existing data does not 

allow a more concise analysis at this time. This study does 

indicate the need for continued collection of methane data 

and analysis for individual and public water-supply wells to 

document methane concentrations for water wells in New 

York State.

Table 1. Distribution of dissolved methane concentrations by geologic age.

[<, less than; >, greater than]

Geologic age of water-bearing formation

Number of wells by methane concentration (in milligrams per liter)

Nondetect < 1.0 1.0–10.0 10.1–28.0 > 28.0 Number 

of wells

Percent 

of wells

Pleistocene & Upper Cretaceous (glacial) deposits 75 45 5 3 1 129 54

Devonian 14 19 10 7 3 53 22

Silurian 2 8 1 2 0 13 5

Upper and Middle Ordovician 3 5 1 3 1 13 5

Lower Ordovician & Upper Cambrian 7 6 1 0 0 14 6

Precambrian 9 4 0 0 0 13 5

Unknown & other (springs) 3 0 0 1 0 4 2

Number of wells and springs 113 87 18 16 5 239

Percent of wells and springs 47 36 8 7 2 100
References

Busenberg, E., and Plummer, L.N., 2000, Dating young ground 

water with sulfur hexafluoride—Natural and anthropogenic 

sources of sulfur hexafluoride: Water Resources Research, 

v. 36, p. 3011–3030.

Eltschlager, K.K., Hawkins, J.W., Ehler, W.C., and Baldassare, 

Fred, 2001, Technical measures for the investigation and 

mitigation of fugitive methane hazards in areas of coal 

mining: U.S. Department of the Interior, Office of Surface 

Mining Reclamation and Enforcement, 125 p., at http://www.

techtransfer.osmre.gov/NTTMainSite/Library/hbmanual/

methane/methane.pdf.

Fisher, D.W., Isachsen, Y.W., and Rickard, L.V., 1970, Geologic 

map of New York State: Albany, N.Y., New York State 

Museum Map and Chart Series no. 15, scale 1:250,000.

Hill, D.G., Lombardi, T.E., and Martin, J.P., 2003, Fractured 

shale gas potential in New York, accessed December 2011, at 

http://www.pe.tamu.edu/wattenbarger/public_html/Selected_

papers/--Shale%20Gas/fractured%20shale%20gas%20

potential%20in%20new%20york.pdf. 

Komor, S.C., 2002, Groundwater age dating in community 

wells in Oswego County, New York: U.S. Geological Survey 

Open-File Report 01–032, 16 p., at http://ny.water.usgs.gov/

pubs/of/of01232/.

Molofsky, L., Connor, J., Wylie, A., and Wagner, T., 2011, 

Methane in Pennsylvania water wells unrelated to Marcellus 

shale fracturing: Oil and Gas Journal, v. 109, no. 49, 12 p. 

at http://www.ogj.com/1/vol-109/issue-49/explorationdevelopment/methane-in-pennsylvania-water-full.html. 

Nystrom, E.A., 2011, Groundwater quality in the Lake 

Champlain Basin, New York, 2009: U.S. Geological Survey 

Open-File Report 2011–1180, 42 p., at http://pubs.usgs.gov/

of/2011/1180/.

Nystrom, E.A., 2012, Groundwater quality in the Delaware and 

St. Lawrence River Basins, New York, 2010: U.S. Geological 

Survey Open-File Report 2011–1320, 58 p., at http://pubs.

usgs.gov/of/2011/1320/.

Osborn, S.G., Avner, Vengosh, Warner, N.R., and Jackson, 

R.B., 2011, Methane contamination of drinking water 

accompanying gas-well drilling and hydraulic fracturing: 

Proceedings of the National Academy of Sciences, 5 p., at 

www.pnas.org/cgi/doi/10.1073/pnas.1100682108.

Plummer, L.N., Busenberg, E., and Böhlke, J.K., among authors 

of the International Atomic Energy Agency (IAEA), 2006, 

Use of chlorofluorocarbons in hydrology—A guidebook, STI/

PUB/1238, 277 p., 111 figs.

Reddy, J.E., and Risen, A.J., 2012, Groundwater quality in 

the Upper Susquehanna River Basin, New York, 2009: U.S. 

Geological Survey Open-File Report 2012–1045, 29 p., at 

http://pubs.usgs.gov/of/2012/1045/.

Schruben, P.G., Arndt, R.E., Bawiec, W.J., King, P.B., and 

Beikman, H.M., 1994, Geology of the conterminous United 

States at 1:2,500,000 scale—A digital representation of the 

1974 P.B. King and H.M. Beikman Map: U.S. Geological 

Survey Digital Data Series DDS–11. 

Solomon, D.K., Schiff, S.L., Poreda, R.J., and Clarke, W.B., 

1993, A validation of the 3H/3He method for determining 

groundwater recharge: Water Resources Research, v. 29, 

no. 9, p. 2951–2962. 

Yager, R.M., Kappel, W.M., and Plummer, L.N., 2007, Halite 

brine in the Onondaga trough near Syracuse, New York—

Characterization and simulation of variable-density flow: 

U.S. Geological Survey Scientific Investigations Report 

2007–5058, 40 p., at http://pubs.usgs.gov/sir/2007/5058.

By William M. Kappel and Elizabeth A. Nystrom

For more information, please contact:

New York Water Science Center

U.S. Geological Survey

30 Brown Road 

Ithaca, New York 14850

Information request:

(518) 285-5602

or visit our Web site at:

http://ny.water.usgs.gov

For more information on the USGS—the Federal source for science about the Earth, its natural and living 

resources, natural hazards, and the environment, visit http://www.usgs.gov or call 1–888–ASK–USGS.

For an overview of USGS information products, including maps, imagery, and publications, 

visit http://www.usgs.gov/pubprod