Anschutz Exploration

Big Flats Fact Sheet
November 2010


New York State Department of Environmental Conservation
Division of Mineral Resources, Region 8
6274 East Avon-Lima Road, Avon, New York 14414-9519
Phone: (585) 226-2466 • Fax: (585) 226-6323
Website: www.dec.ny.gov


This fact sheet provides basic information obtained by DEC associated with turbidity and methane issues found in some residential water wells in a neighborhood located north of the Elmira/Corning Regional Airport in the town of Big Flats.

DEC issued permits to Anschutz Exploration Corporation (Anschutz) to drill the Dow #1 and Dow #2 natural gas wells and is responsible for overseeing these operations.  DEC has no regulatory jurisdiction regarding private drinking water wells with the sole exception of a registration process for water well drillers.

There are a number of reasons why water wells have sudden changes in quality and quantity. Seasonal variations, stress on the aquifer from water wells, mechanical failures and build-up of minerals and/or bacterial compounds are just some of the factors that must be examined when evaluating water well degradation.

When DEC was informed on September 13, 2010 of concerns from residents that a nearby drilling operation may have adversely impacted their water quality, DEC chose to investigate those private wells by checking water levels and water turbidity conditions.

Methane

Methane commonly occurs in residential water wells since it is often present in bedrock at shallow depths. Often the well owner is not aware of the presence of methane in the well. Methane is colorless, odorless, and not toxic but there could be an explosive hazard if the well is not properly vented. Water well drillers have informed DEC that they encountered naturally occurring shallow gas during drilling and have been aware of natural gas in area water wells for years. DEC was also informed by a water well driller that methane was present in one residential water well in the neighborhood currently experiencing problems for some time prior to the drilling of the nearby gas wells.  Drilling and DEC inspection records from the gas wells in question indicate that pre-existing methane was already present at shallow depths when the wells were drilled.

The way the gas wells were constructed makes it unlikely that gas from deeper formations could migrate through multiple cemented casing strings into any aquifers near the surface. Wells were constructed with three casings cemented back to surface and through all shallow fresh water zones.

DEC has provided information and urged residents with gas detected in their wells to vent their wells. Website links for guidance on proper well venting are on the following page.

Turbidity

Several homeowners experienced turbidity in their water wells. Turbidity in private water wells is rarely observed due to gas well drilling operations while using compressed air to drill the surface hole through shallow bedrock aquifers. Turbidity would be temporary and typically cease within hours after drilling through the aquifers. DEC received no complaints from residents of turbidity in the neighborhood currently experiencing problems when the surface holes were drilled in April and July 2010. Once the well casing is cemented through the aquifers, there would be no potential for further disturbance.

Depth of Wells

The water wells experiencing methane and turbidity problems were drilled into bedrock which was encountered at approximately 60 feet or more in depth, and are located more than 2,000 feet from Anschutz’s Dow #1 and Dow #2 wells. DEC has not received complaints from residents with shallower water wells that are closer to the gas wells and screened above bedrock in the sand and gravel aquifer.

Next Steps

DEC will continue to monitor water levels in the neighborhood and keep in contact with the residents about their well conditions. DEC is also coordinating with Anschutz to further evaluate and test the gas well casing and cement integrity to confirm that gas migration is not occurring in the annular space between the casing and borehole wall into the shallow bedrock aquifers.  Anschutz has recently completed testing of the casing integrity and running a series of logs to evaluate the potential for gas to migrate behind the casing on the Dow #2 well.  The results of the internal pressure testing on the casing and the log evaluations gave no indication of gas migration from zones where gas may be present either inside or outside the casing.  Similar logging and testing are currently being conducted on the Dow #1 well.

Additional Resources

For site-specific questions, contact New York State DEC Regional Mineral Resources Supervisor, Linda Collart, at (585) 226-5376 or e-mail at: lacollar@gw.dec.state.ny.us;
The Chemung County Health Department contact is: (607) 737-2019; or  
The Big Flats town contact is: Teresa Dean, Town Supervisor at (607) 562-8443.

For generic health-related information, contact the New York State Department of Health Bureau of Water Supply Protection at (518) 402-7650 or e-mail at: bpwsp@health.state.ny.us

Websites for well venting information:
drinknwaterplus.com
dmre.ky.gov