Antero Resources Mitigation Strategies and BMP – Wolf Springs Mesa County (TPD1211027)

Air Quality and Odor Control

• All production tank venting emissions are routed to a VOC combustor
  • Purpose is to reduce odors by controlling VOC emissions from condensate flashing and working and breathing losses
  • VOC combustors operate with auto-igniters
    • Purpose is to keep VOC combustors lit
    • Flowback gas and well flow testing gas routed to temporary flare
    • Well Pad Location Telemetry/Remote Monitoring
      • Reduces well pad location truck/pumper visits
      • Low profile antenna equipment
      • Frac/Flowback Storage Tank Hatches
        • Tank hatches are closed and latched until the tanks are being prepared to receive flowback water
          • Hatches closed but unlatched when receiving flowback fluids
• Operate with odor absorbing blanket or other similar odor control device when full
• Diesel Powered Drilling Rig Generators
  • Drill rig engines are regulated as non-road engines under the Standards of Performance for Stationary Compression Ignition Internal Combustion Engines (40CFR 60, 85)
  • Diesel engines powering the drilling rigs are certified to at least the Tier 2/3 standards
    • Ensure that engine fuel meets regulated sulfur content requirements.
    • Separators and Wellheads – Fugitive VOC emissions from valves and flanges
      • Operate with low-bleed pneumatic devices

Fugitive Dust

• Well pad location and access roads graveled to reduce dust impacts
  • Soiltac® and/or liquid dust suppressants are used to mitigate fugitive dust emissions on access roads and well pad location
  • Buried water lines to minimize fugitive dust emissions from truck traffic
  • Limiting vehicle speeds during well pad location site access
    • Road sweeping to reduce fugitive dust and mud tracking onto roadways where practicable

Groundwater and Surface Water Resources

• Closed loop (pitless) drilling systems; no reserve, drill cuttings or frac/flowback pits will be constructed
• Water used for well completions will be recycled as practicable
• Frac/Flowback tank area lined and/or tanks equipped with portable spill berm containment structures
• Production tank containment area bermed and lined with plastic
• Well pad location perimeter berms to contain unintended fluid releases
• Voluntary Water Well Testing Program
  • Pre – all water wells/springs within ½ mile radius of the surface-hole location for each well on a well pad location
  • Post – within one year a follow-up test on the pretest wells/springs or when all wells drilled and completed on a well pad location
  • Where practical water quality testing as requested by landowner for water wells, springs, potable water and agriculture water
    • Comply with provisions of water well testing in surface use agreements
    • Wetland/drainage survey and mapping conducted prior to site disturbance
      • Containment for well pad location within 500 feet of surface water is 110 percent secondary containment for any volume of fluids contained at a well pad location during drilling and completion operations

Planning Infrastructure and Development Activities which Minimize Impact

• Antero setbacks of 500 feet from dwelling units – COGCC setbacks are 150-200 feet
• Well pad location construction not to exceed 3.5 acres
• Bury all gas and water pipelines adjacent to roads whenever possible
• Water used for well completions will be recycled as practicable
  • Above-ground facilities located to minimize visual effects (e.g. production tanks will be low profile tanks and painted to mitigate visual impacts)

Spill Prevention, Control and Countermeasure (SPCC Program)

• Annual SPCC Training
• SPCC inspections conducted quarterly
• Well pad location perimeter berms will be constructed
  • Purpose is to provide tertiary spill containment for production tanks and separators
  • Provides secondary spill containment for all material activities on site not just oil storage.
  • Provides a barrier between well pad location activities and surrounding areas
  • Frac/Flowback tank area will be located in an area with down gradient well pad location perimeter berm
    • Frac/Flowback tank area lined to mitigate seepage losses from the unintended spillage of well completion fluids, or frac/flowback tanks will be placed in portable spill berms
    • Standard Operating Procedures (SOPs) training performed for handling and transfer of frac/flowback and produced fluids
    • High level overflow alarms installed on production tanks
    • Covered drip buckets for condensate and produced water tanks and loadout lines
      • Purpose is to minimize spillage and drips that occur during normal loading activities
      • Designed to catch residual liquids that remain in lines after the tank valves and truck valves have been closed
      • Covers minimize VOC emissions and exposure to storm water