Evaluation of Unconventional Natural Gas

DevelopmentPotential Impacts to

Aquatic Environments

Kathleen Patnode – PAFO

TNC Pennsylvania Chapter 2010

Resource ConcernsWATER QUANTITIY & QUALITY

Demand • 5 to 7 million gallons per well• from small streams by truck• from rivers by pipeline• need reduced by recycling of used water

Water withdrawal regulations• varies between states • varies between and within river basins

WATER QUANTITY

Chemicals added to Frac Water • Acids• Friction Reducers• Surfactants• Gelling Agent• Scale Inhibitor• pH Adjusting Agent• Oxygen Scavenger• Breaker• Crosslinkers• Iron Control• Corrosion Inhibitor• Antibacterial agent

WATER QUALITY

Wastewater Issues

Flowback Water – hydraulic fracturing fluid that flows back to surface• up to ≈ 70 % flows to surface• most recovered in first 1 to 2 weeks• TDS increases up to 200,000 ppm• frac chemicals, trace elements & NORM

Characterizing the Waste

Wastewater IssuesFlowback Water Management Options • Deep Well Injection• Discharge to POTWs• Direct Reuse for Fracking• Treatment for Reuse

Reuse Pressure to:• reduce stream and

river withdrawal • eliminate

wastewater pass-through at POTWs

Contamination of water sources

No backflow preventers installed

Contaminated water and invasive species in vac trucks can discharge into water source (well, tank, lake, stream)

Brine Treatment at Conventional Treatment Plants

• VOCs – blown off• Oil & Grease,

removed• Metals, removed• Does NOT treat

TDS salts or NORM

• TDS in = TDS out

Reusing WastewaterTreatment for Reuse • 5-7 acre impoundments for mixing• impoundments provide reuse water to multiple wells • ~2000 truck loads of wastewater on rural roads• use of reuse lines from impoundments to local wells • high risk of truck spills and waste line breaks• spills are not being reported to NRC

Potential Impacts to Natural ResourcesImpact Trust Resource

Ground water contamination public lands, water wells, T&E aquatic species, aquatic biota

Surface water contamination public lands, T&E aquatic species, aquatic biota

Flowback water disposal in evaporation ponds (COWDFs)

birds, breeding amphibians

Proppant (resin-coated sand) spills bird species(sand ingested as grit, effects unknown)

Water depletions T&E aquatic species, aquatic biota

Potential Contamination Pathways

• Well Blowouts

• Groundwater contamination• Inadequate well cementing

• Surface water contamination• Frac flowback spills• Leaking or overflowing open water impoundments• Insufficient wastewater treatment

Water quality violations: conductivity, osmotic pressure, barium, strontium, chloride, aluminum

Mortality:fish, aquatic invertebrates, amphibians

Documented Impacts to FWS Trust ResourcesFrac Flowback SpillAcorn Creek, KY in 2007

• Threatened Blackside dace• Frac flowback spilled into creek• Lowered pH from 7.5 to 5.6• Increased conductivity

• 100 to 35,000 uS/cm• Fish & aquatic invertebrate mortality

Source: Anthony Velasco, Environmental Contaminants Specialist, USFWS, KY

UNAUTHORIZED TAKE

LACK OF COORDINATION WITHOUT FEDERAL NEXUS

EROSION AND SEDIMENTATION

Extensive disturbanceInsufficient E&S controlsMultiple creek crossingsDrilling mud releases

Objective to address key science issues and data gaps

• Geological framework• Changes in water availability (groundwater and surface water)• Changes in water quality (groundwater and surface water)• Changes in air quality (stray gas and dust)• Induced seismicity• Changes in landscape and habitat condition• Effects of these changes on

• biological resources• human health• ecosystem services

Federal Interagency Team

Mussel Interagency Team (FWS, USGS, EPA)

-determine no effect concentrations for ions in flowback water-work with state to implement protective permit limits-establish injury levels for spill NRDA

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Best Management Practices – Water Quality

• Development & use of “green” chemicals

• Closed loop drilling & fracturing• No pits & reuse of frac water

• Treatment and reuse of frac water

• Development & use of dry-frac process• Liquid CO2

• Explosives

• Development of spill contingency plans• public lands / easements• Other areas with sensitive species