Month: November 2011

Conclusions of “Duke Paper” Not Supported By Limited Data

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The Proceedings of the National Academy of Sciences (PNAS) recently published a letter coauthored by Mark Orzechowski, P. G.,  of Civil & Environmental Consultants, Inc. and Tarek Saba, Ph. D., of Exponent, Inc.  The letter was written in response to an article published earlier this year by PNAS, entitled Methane Contamination of Drinking Water Accompanying Gas-Well Drilling and Hydraulic Fracturing, written by Osborn et al.  The article is typically referred to as the “Duke Paper” by many in the natural gas industry.  Based on the results of 68 water-well samples, Osborn et al. concluded that there was evidence of increased concentrations of thermogenic methane in water wells near active gas extraction areas compared with water wells outside active gas extraction areas.  The Osborn study also concluded that the thermogenic methane in the water wells was consistent with Marcellus Shale gas.

The response letter by Mr. Orzechowski and Dr. Saba indicates that the data set presented in the study was too limited to support the conclusions provided by the authors.  In addition, Mr. Orzechowski and Dr. Saba provide evidence that natural gas from the much shallower Lock Haven Formation is the more likely source of methane in the water wells sampled in the study (many of those water wells are completed in the Lock Haven Formation).  The studies behind the “Duke Paper” also failed to analyze for carbon and hydrogen isotopes in the methane and ethane, which would be required to determine if the methane was related to the Marcellus gas extraction operations.  The response letter concluded the limited data presented in the “Duke Paper” do not support the presence of gas from the Marcellus Formation in private water wells in the vicinity of gas extraction operations.  Click here to see the response letter.

If you have questions on the conclusions reached by Mr. Orzechowski and Dr. Saba, please contact Mark Orzechowski, P.G., (morzechowski@cecinc.com) at 800-365-2324.

Cleanup of Chlorides in Soils at Natural Gas Well Sites

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As described in our previous posting, CEC recently learned that the Pennsylvania Department of Environmental Protection (PADEP) will soon be issuing draft guidance that standardizes the regulatory requirements for reporting, remediating, and restoring areas impacted by spills or releases from oil and gas (O&G) well operations. That guidance specifies that the remediation of specific types of releases will be referred to the Bureau of Environmental Cleanup and Brownfields (BECB) for oversight of remedial activities which will be performed in accordance with the provisions of the Pennsylvania Land Recycling Program, commonly known as Act 2. Among the other provisions of Act 2, it requires that a site be remediated using one of three standards available in Act 2: Background Standard; Statewide Health Standard; or Site-Specific Standard. One parameter that must often be addressed after releases at natural gas well sites is chloride. Act 2 does not have a Media Specific Concentration (MSC) established for chlorides in soils for use in achieving the Statewide Health Standard, which could preclude the use of that cleanup standard. The lack of an established regulatory standard for chlorides in soil to guide remedial activities is also a potential concern in surrounding states.
The term “chloride” does not refer to any specific compound but is a category of substances that are either present in the deep groundwater encountered during well drilling to reach the Marcellus Shale, or are added to drilling muds or hydrofracturing fluids to facilitate development of a gas well.  The most common chlorides of interest include sodium chloride, calcium chloride, magnesium chloride, ammonium chloride, potassium chloride, and barium chloride. Act 2 established a MSC of 250 mg/l for chlorides in groundwater based on the Secondary Maximum Concentration Level (SMCL) promulgated by the United States Environmental Protection Agency (EPA). However, as stated earlier in this blog, Pennsylvania does not have a MSC for chlorides in soil. Both PADEP and industry personnel have requested guidance on how to address chlorides in soils.  As a result, PADEP is considering proposing the use of a Site-Specific Standard for chlorides in soil that would address both the potential soil-to-groundwater pathway and the ecological pathway that could impact species and habitats of concern.
The soil-to-groundwater pathway could be evaluated by submitting samples of impacted soil to a laboratory for analysis using the Synthetic Precipitation Leaching Procedure (SPLP).  Soils with a SPLP-leachable chloride concentration less than the groundwater MSC of 250 mg/l would be considered as having achieved attainment with the soil-to-groundwater MSC.  Additionally, potential surface water impacts to seeps/springs and stormwater runoff would be evaluated using the water quality standard (WQS) of 250 mg/l.  The potential for using soil to groundwater leachability calculations to derive cleanup standards for chlorides and other soluble constituents such as sulfate and bromide may also be considered since methods for performing these calculations have already been established under Act 2.
Under the existing Act 2 process, an evaluation of the ecological risk must be performed to address potential species and habitats of concern, but the evaluation does not have to consider impacts to common plant species.  PADEP is considering implementing additional requirements in an attempt to prevent the development of a Site-Specific Standard that would be considered to be protective of the species and habitats of concern specified in the Act 2 regulations while allowing residual chloride concentrations to remain in the soil that would negatively impact vegetation on the property.  These additional requirements would include an assessment of the chloride tolerance of the vegetation present at a site to develop a Site-Specific Standard.  This site-specific vegetation chloride tolerance approach could result in a large variation of chloride cleanup criteria from site to site.  For example, some agricultural crops can tolerate total chloride concentrations in soils of up to 1,500 mg/kg while more sensitive species cannot tolerate total chloride concentrations in soils at concentrations in the range of 500 to 800 mg/kg.  Proper selection and application of soil amendments can reduce the amount of chlorides and other ions (particularly sodium) in the soil that are potentially deleterious to plants, thereby reducing the potential toxicity due to residual chloride concentrations.
If you have questions on how the spill and release guidance might apply to your operations, please contact Bo Valli, P.G., (bvalli@cecinc.com) or Tom Maher, P.G., (tmaher@cecinc.com) at 800-365-2324.

PADEP to Issue Draft Guidance for Response to Releases and Spills From Gas Sites

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CEC recently learned that the Pennsylvania Department of Environmental Protection (PADEP) will soon be issuing draft guidance that standardizes the regulatory requirements for reporting, remediating, and restoring areas impacted by spills or releases from oil and gas (O&G) well operations. The guidance will be applicable to spills and releases from conventional well operations as well as unconventional shale gas exploration and production (E&P) operations involving the Marcellus and Utica Shales. The guidance is being developed to provide a consistent and uniform response program for releases and spills, and to establish a regulatory framework within which PADEP will exercise its administrative discretion when dealing with releases.

Until recently, responses to spills and releases from O&G operations were administered by the Office of Oil and Gas Management (OOGM), which was formerly referred to as the Bureau of Oil and Gas Management.   The various OOGM offices were free to exercise their discretion as to how to address each spill on a case-by-case basis. The incident reporting mechanism and overall responsibility for handling releases will remain with the OOGM, while the remediation of specific types of releases will be referred to the Bureau of Environmental Cleanup and Brownfields (BECB) for oversight of remedial activities. The practice of referring spills and releases to the BECB has already occurred with the issuance of several Notices of Violation that direct responsible parties to contact the BECB regarding procedures for conducting cleanups under the provisions of the Pennsylvania Land Recycling Program, commonly known as Act 2.  Specifically, environmental remediation standards established under Act 2 will be used whenever site remediation is required under the Clean Streams Law, the Air Pollution Control Act, the Solid Waste Management Act, the Hazardous Sites Cleanup Act, and the Storage Tank or the Spill Prevention Act.

The two types of releases specified in the guidance are based on their potential to cause environmental harm.  The first type is a release of regulated substances of less than 42 gallons that does not pose a danger of polluting waters of the Commonwealth and does not result in damage to the property. The guidance will specify that releases of that type will be cleaned up by removing visibly impacted soil.  For releases that exceed those criteria, performance of remediation of the impacted media will be required in accordance with the administrative and technical requirements of Act 2.  The cleanup standard used may be selected from three standards available in Act 2: Background Standard, Statewide Health Standard, or Site-Specific Standard. The Responsible Party would be required to follow the administrative process set forth in Act 2, including the submittal of a Notice of Intent to Remediate (NIR), publishing public notices and submitting a Final Report demonstrating attainment of the selected standard.  The submission of a NIR and public notifications can be waived under Act 2 if the final report is submitted within 90 days of the release.

Some potential concerns related to this guidance include:

  • The time needed to administratively complete the Act 2 process.  The Act 2 process will add to the administrative requirements and likely add to the time needed to obtain a release from PADEP. As indicated earlier in this posting, the administrative requirements could be reduced somewhat if a spill or release referred to the BECB is remediated to attainment of one of the remediation standards available under Act 2.
  • Potential for negative publicity: Increased negative publicity for the natural gas industry may result should the public notification portion of the Act 2 regulations be necessary.
  • Deed covenant requirement: Activities of natural gas operators are usually performed on leases and there is uncertainty about how landowners will react to the deed notification/environmental covenants required when utilizing site-specific cleanup standards under Act 2.  This would be the case for soils impacted by chlorides, a chemical of concern often associated with releases at natural gas sites.  There is no Statewide Health Standard for chloride in soil; and, as such, only the Site-Specific Standard and Background Standard are available for use under Act 2.

If you have questions on how the spill and release guidance might apply to your operations, please contact Bo Valli, P.G. (bvalli@cecinc.com) or Tom Maher, P.G. (tmaher@cecinc.com) at 800-365-2324.