Grizzly Energy LLC Grizzly Operating LLC Elk Basin

Grizzly Energy, LLC Grizzly Operating, LLC Elk Basin Gas Plant Regional Haze Four Factor Analysis

Current and Future Q/d Year Tons (PM, SO 2, NOx) Distance to N. Absaroka (Class 1 Area) 2014 2455. 6 52 km 46. 47 2018 1460. 56 52 km 28. 08 2019 1260. 79 52 km 24. 25 2028 Probable Potential to Emit (PTE) 945 52 km 18. 17 580 52 km 11. 15 2028 Probable Actual Emissions 2 Q/d • Q/d is calculated by total tons of PM, NOx and SO 2 divided by the distance to the nearest Class I Wilderness Area. The area impacted by the Elk Basin Gas Plant is the North Absaroka Wilderness area. • Decrease in emissions for report year 2019 due to using actual stack test data in the Air Emissions Inventory (AEI) instead of using the allowable emissions limit and lower Sulphur content in the gas from the field and current production decline rate that is extrapolated into the future. • Probable Q/d assumes that the proposed options will be installed at the current production rates and runtime.

Elk Basin Gas Plant Engine Compressor Stations (EC 1 -EC 9) Source/ Source Category Pollutant Analyzed Nine(9) Natural Gas Fired Lean Burn Engine Compressor Stations 11000 HP Total(5 – 1200 HP, 31000 HP & 1 -2000 HP • 3 NOx Control Considered Low Emissions Combustion Control (LEC) Cost in $/ton of pollutant reduction (Factor 1) $2, 200 per ton Compliance Energy and Non Timeframe -Air Quality Environmental (Factor 2) Impacts (Factor 3) 3 to 5 years after SIP Remaining Useful Life (Factor 4) Increase use in electricity approx. 20 to 25 years. $11, 500 in Engines annual cost per manufactured 1200 HP engine. in 1948 Potential decrease in PM due to ideal combustion. $2, 200/ton comes from the EPA Cost Manual for LEC on Lean Burn Compressor Engines. The range in the model indicates $1, 000/ton and $2, 200/ton. Industry experience demonstrates that Low NOx Burners cost approximately $300, 000 each on newer systems. The nine engines would total $2. 7 MM. This would equate to roughly $1, 500/ton with the PTE decrease from 2, 178. 6 to 385. 05 TPY NOx. Since the engines were manufactured in 1948, the assumption that additional modifications will be made increases the price to the top range of $2, 200.

Elk Basin Gas Plant Tail Gas Incinerator (INC-1) Source/ Source Category Incinerator – Natural Gas Tail Gas Combustion (INC-1) Option #1 Incinerator – Natural Gas Tail Gas Combustion (INC-1) Option #2 • • • 4 • Pollutant Analyzed SO 2 Control Considered Optimizing current 2 – Stage Claus Plant/SRU (Actual Recovery to 96. 5% annual average) Adding a 3 rd Stage to the Claus Plant and a Tail Gas Treating Unit (TGTU) (permitted recovery to 96. 5% annual average) Cost in $/ton of pollutant reduction (Factor 1) $24, 000/ton $200, 000/ton Compliance Timeframe (Factor 2) 2 -5 Years 3 – 5 Years after SIP Energy and Non. Air Quality Environmental Impacts (Factor 3) Increase use in electricity with added instrumentation. Optimizing Sulphur catalyst which would decrease the amount Sulphur catalyst being sent to the landfill. Increase use in electricity. Increase in Sulphur catalyst which would increase the amount Sulphur catalyst being sent to the landfill. Remaining Useful Life (Factor 4) 30 years Current SRU SO 2 recovery is permitted at 93. 5%. The actual annual average recovery rate is 95. 1%. Looking to increase actual to 96. 5%. $24, 000/ton assumes $1. 2 MM in engineering studies, instrumentation and automation to ensure recovery efficiencies of 96. 5% can be met for a decrease in 50 tons/year. Permitted Limit would still be 93. 5% Adding additional stages to the Claus plant will increase the permitted average to 96. 5% according to the Sulphur Recovery Regulations (Chapter 18, Table 18 -1). $200, 000/ton assumes the cost of the 3 rd or 4 th stage to the Claus plant and a TGTU will cost $16 MM and decrease actual emissions by 80 tons/year. This would trigger a permitted limit of 96. 5% recovery with actuals around 98%.

Appendix 5

6 • The summary table in this slide represents the Title V Permitted sources at the Elk Basin Gas Plant. • The Analysis focused on the nine (9) compressor engines (EC 1 – EC 9) and the tail gas incinerator (INC-1) since they are the largest emitters of PM, NOx and SO 2. • The boilers (EB 1 -EB 3) and other sources are not included in the analysis due to the low impact they have. The PTE of the boilers is just over 5 TPY combined and actual emissions with stack testing data are just over 1 TPY.