Related by context. Frequent words. (Click for all words.) 50 fracking fluid 46 hydraulic fracturing 46 fracking fluids 44 COGCC 44 Marcellus wells 43 Hydraulic fracturing 43 flowback 43 reinjection 43 fracking 43 methane hydrate 42 geologic formations 42 total dissolved solids 42 dissolved solids 42 fracing 42 proppant 41 Fracking 41 Neslin 41 injection wells 40 shale formations 40 drillers 40 extractable 40 hydrocarbon 40 shale 40 methane hydrates 40 coal slurry 40 subsurface 40 Marcellus shale 40 wellbore 40 desorption 39 Marcellus Shale formation 39 polluted groundwater 39 Bakken Formation 39 wells 39 frac 39 fracs 39 frack 39 natural gas 39 Ogallala Aquifer 38 geological formations 38 compressor stations 38 additive MTBE 38 coalbed methane 38 horizontal drilling 38 hydrofluoric acid 38 Bakken formation 38 poultry litter 38 Marcellus Shale 38 analyte 38 Clean Water Act 38 extraction 38 hydrofracking 37 groundwater remediation 37 brine 37 horizontal wells 37 harmful contaminants 37 frac stages 37 Barnett Shale 37 liquids 37 fly ash 37 deepwater wells 37 Petro Reef 37 hydrocarbons 36 CNX Gas 36 Barnett shale 36 livestock manure 36 gas hydrates 36 Deepwater Horizon blowout 36 groundwater contamination 36 groundwater 36 contaminants 36 Petrosearch 36 underground piping 36 Safe Drinking Water 36 chloramine 36 drilling fluids 36 oil sands 35 wellhead 35 contaminate groundwater 35 Fayetteville shale 35 gasline 35 economically recoverable 35 Fayetteville Shale 35 gasoline additive MTBE 35 producible 35 hydrogeological 35 North Slope 35 Albany Shale 35 Bcf 35 Mcf d 35 chemical additives 35 chlorides 35 wells drilled 35 aquifer 35 stage fracture stimulation 35 coal seams 35 categorical exclusion 34 MTBE 34 gravity drainage 34 Fracturing 34 hydrates 34 sedimentary basins