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Shale Gas Greening of America?. By Ethan Bellavance, Kaylyn Hawkes, Justin Grodman, Dan Hale, Caitlin Shea. What is Shale Gas?. 95.5% Methane, 2.5% Ethane, 0.2% Propane. Large Domestic Source of energy 5.4 Tcf/year in 1998 to 8.9 Tcf/year in 2007.
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Shale GasGreening of America? By Ethan Bellavance, Kaylyn Hawkes, Justin Grodman, Dan Hale, Caitlin Shea
What is Shale Gas? • 95.5% Methane, 2.5% Ethane, 0.2% Propane. • Large Domestic Source of energy • 5.4 Tcf/year in 1998 to 8.9 Tcf/year in 2007 http://www.uniongas.com/aboutus/aboutng/composition.asp Arthur, J Daniel. (2008). An Overview of Modern Shale Gas Development in the United States. AllConsulting. http://www.all llc.com/publicdownloads/ALLShaleOverviewFINAL.pdf USGS
Natural Gas Production • Arthur, J Daniel. (2008). An Overview of Modern Shale Gas Development in the United States. AllConsulting. http://www.all llc.com/publicdownloads/ALLShaleOverviewFINAL.pdf
Types of Unconventional Natural Gas • Tight Gas Sands • Coal Bed Methane • Gas Shale’s- Most Expansive Growth, Comprise 50-60% of countries reserves growth by 2011 Arthur, J Daniel. (2008). An Overview of Modern Shale Gas Development in the United States. AllConsulting. http://www.all llc.com/publicdownloads/ALLShaleOverviewFINAL.pdf
Three factors that have created the unconventional natural gas industry. • Directional Drilling • Hydraulic Fracturing • High well prices http://www.theoildrum.com/files/perforating3_0.jpg
Marcellus Shale Deposited over 350 Million years ago. USGS
Objectives • Assess whether water release from acid fracturing is detrimental to surface water and aquifers? • Determine if the amount of water necessary for acid fracturing can be sustainably extracted from existing watershed aquifers. • Observe how the process of acid fracturing effects local ecosystems. • Analyze the national and local socioeconomic impact of acid fracturing in regard to potential job creation, US energy profile, social values, and land use.
Hydraulic Fracturing • Three treatments available • Foam • Gel • Slickwater
Slickwater Treatments • Introduction of “rock acid” - cleans out well • Slickwater plug- formed with water, sand and additives. Friction reducing chemicals to allow faster pumping. • Fracturing- over a million gallons of water, sand and chemicals. • Flush- recovery of water in pumps to allow collection of gases.
http://www.propublica.org/special/hydraulic-fracturing-nationalhttp://www.propublica.org/special/hydraulic-fracturing-national
Acid Fracturing • Each Fracture is unique • Based on local stress conditions. • Typically contains 98% water and sand, and 2% chemicals • Currently 197 products used in slickwater process, 152 products known NYS Department of Environmental Conservation, 2009).
Chemical Additives (NYS Department of Environmental Conservation, 2009)
Water Withdrawals • Variety of sources • Proximity to drill site • Three to four million gallons for typical horizontal shale gas well • 0.5 to six million gallons for hydraulic fracturing of the Marcellus Shale • Used in relatively short time period
Water Transport • Location and type of sources • Longer route distance = more expensive and less water efficiency • Reliability of source as constant supply • Rate and timing of withdrawals are key
Effects on Water Resources • Reduction in stream flow • Stream’s uses and public supplies altered • Adjacent habitats altered • Recreational uses, potable and culinary uses, fish survival and propagation, disposal of wastes
Effects Continued • Depletion of aquifers • Cumulative withdrawals • Occurs when volume extracted > recharge rate • Potentially lead to reduction to aboveground bodies of water • Translocation of water from watershed
Ecosystem Impacts • Adverse effects on local ecosystems • Natural cycles essential to ecosystems • Alterations in flow regimes affect habitat • Improper techniques and structures for withdrawing • Water uptake flow velocity • Transporting invasive species
Effects on Wetlands • Susceptibility to draining of water • Quantity withdrawn has direct impacts depending on natural dynamics of flow • Variety of species significantly affected
Produced Water (Arthur 2008) • Byproduct of the stimulation and drilling process • Before natural gas can be recovered, water that is pumped into the shale must be allowed to flow out as “produced water” • Can consist of fracturing fluids, heavy metals, brine waters, dissolved minerals or organic matter from the shale
Composition of a Fracture Fluid (Arthur 2008)
Chemical Additives No “one size fits all” percentage that are added to fracture fluid Additives in a single hydrofrac job result in approximately 15,000 gallons of chemical waste Most are proprietary All are necessary in order to ensure the success of the drilling process Risk to human and environmental health is low (Soeder 2009), (Arthur 2008), (NYSDEC 2009)
Threats to Drinking Water (Cornell University 2010) Drilling must pass through shallow drinking water aquifers Well casings made of steel and concrete can become defective or damaged Potential chemical spills Road/construction activity
Wastewater Treatment Plants (Soeder 2009) Cannot handle the quantity of water used Unsure of the chemical composition of the proprietary chemicals used in the acid fracturing process Do not successfully remove salts and other dissolved solids
Additional Treatment Methods (NYSDEC 2009), (Soeder 2009) Re-inject produced water into the ground at a shallow depth Re-inject produced water into the ground at a depth below the Marcellus Shale Allow wastewater to evaporate from open pits or tanks Dilute produced water and reuse it in future fracturing operations New technology…
Habitat Fragmentation • Inevitable consequence of all mining practices • Occurs through construction of unpaved roads, pipelines and infrastructure: • Well pads drilling rigs, storage facilities, heavy machinery necessary to mine natural gas and eventually transport it off site
Roads • Generally includes removing large rocks and vegetation, and replacing them with crushed gravel or stone • Each well-site must have an access road • According to NY DEC every 150ft of 30ft access road adds 1/10 acre to the total disturbed surface area attributed to the well site • Highly used fragments, such as access roads, significantly increase impact • Edge sensitive species affected most • Increased erosion contributes to habitat and water-quality degradation
Sedimentation and Erosion • Overflow off roads and impervious drilling pads alters slopes and soils and further ↑ surface water quality issues • Plants rooting is disrupted • Aquatic receptors are affected by increased sedimentation increasing TSS in the water column • Velocity and volume of runoff ↑ with reciprocal ↓ in infiltration (impermeable surfaces) • Chemicals and pollutants are present on impermeable surfaces • Pollutants adhere to eroded sediment particles
Ecological Receptor- Trout • Rising Stake-holder concern • Chesapeake Bay Association PA and NY trout association, land owners, fishermen • Marcellus Shale spans under the Appalachian basin which provides headwaters for numerous streams valued for trout habitat • Salinity, acidity, and toxicity in mine runoff are of concern for trout health and ability to reproduce • Increased impervious surfaces and increase acidity have been shown to negatively affect Brook Trout populations in the NorthEast (Conservation Strategy Work Group, 2005) • Mine drainage in has historically in PA and WV has drastically decreased stream ecological health • USGS records over 3,400 miles of streams and GW contaminated in PA alone due to mining practices (USEPA, 2001)
Edge-related Stress • Increased edge will affect some species more drastically than others • Life history traits, population numbers, physical size, physical size and amount of area needed per individual • Golden-winged and prairie warbler have shown increase abundance in early succession edge areas • Results NOT shown when fragmentation is maintained by constant use and traffic • Cerulean warbler – Edge sensitive species inhabitaing areas along Marcellus Shale territory • Largely impacted by habitat fragmentation due to mining
Soil Compaction & Reclamation • Overburden must be removed to gain access to bedrock • Stockpiling of this material is essential for reclamation efforts • Where overburden is not removed, continuous use of heavy machinery compacts soils • Increased bulk density rates • Creates difficult habitat for plant rooting • Lower water infiltration rates • Contributes to ↑ surface runoff
Reclamation Techniques • Open pits must be backfilled • Soils must be tested for salinity, acidity and toxicity in order to prepare restoration plan • Salinity acidity and toxicity will likely all contribute to Shale gas sites due to: • salts, hydroflouric acid, heavy metal leaching and a variety of chemicals used in the fracking liquid • Grading and scraping to loosen soils and adding Lime and fertilizer are recommended • Many mine Reclamation sites fail due to soil toxicity
Recommendations for Water Management Communicating with local water planning agencies is essential for the operators of the drills in order to manage water sources. Using several large sources of water instead of many smaller ones. Ensuring that the withdrawal of every water source used will not significantly nor permanently deplete that source. Choosing water sources in close proximity to mine site. Ensuring the safe and effective disposal of produced water from the acid fracturing process. Continue to research the proper disposal of produced water in order to create more effective methods of treatment.
Recommendations for Land Use Change In order to protect trout populations, drilling should not be permitted in areas deemed sensitive coldwater habitats. Multiple wells should be placed along the same access road, while utilizing current roads as much as possible. Areas of sensitivity such as steep slopes, wetlands, and streams should be avoided. Proper erosion controls must be implemented. Topsoil must be maintained for proper reclamation. Catch ponds and/or artificial wetlands must be provided to store, filter and monitor surface runoff from mine sites.
Works Cited Arthur, J Daniel. (2008). An Overview of Modern Shale Gas Development in the United States. All Consulting. http://www.allllc.com/publicdownloads/ALLShaleOverviewFINAL.pd Soeder, Daniel and William Kappel. (2009). Water Resources and Natural Gas Production from the Marcellus Shale. USGS. https://webmail.uvm.edu/horde/imp/view.php popup_view=1&index=11782&mailbox=INBOX&actionID=view_attach&id=2&mimecache=e6686c56f385749fe79522412f9e4d3e New York State Department of Environmental Conservation. (2009). Supplemental GenericEnvironmental Impact Statement on the Oil, Gas and Solution Mining Regulatory Program.http://www.docstoc.com/docs/12365971/OGdSGEISFull Cornell University. Water Quality Information for Consumers. http://waterquality.cce.cornell.edu/naturalgasdrilling.htm USEPA (U. S. Environmental Protection Agency). 2001. What is the State of the Environment in the Mid-Atlantic Region? Technical report EPA/903F/F-01/003. Region 3, Philadelphia, Pennsylvania. Conservation Strategy Work Group. (2005) Conserving the Eastern Brook Trout: status, threat and trends. http://www.mmbtu.org/Conserving_Eastern_Brook_Trout.pdf