20231228Exhibit 6.pdf

Intermountain Gas Company
Capacity Enhancement Alternatives NPV by AOI
2023 – 2028
Exhibit No. 6
Intermountain Gas CompanyCanyon County AOINet Present Value
Alternative #Alternative Description Details O&M Cost Used for NPV Net Present Value Year 0 Year 1 Year 2 Year 3 Year 4 Year 5 Year 6 Year 7
N/A Ustick Phase III 4.1 miles - 12 inch HP $12,157,986.07 12,800,000$ (11,787)$ (12,023)$ (12,264)$ (12,509)$ (12,759)$ (13,014)$ (13,274)$
Year 8 Year 9 Year 10 Year 11 Year 12 Year 13 Year 14 Year 15 Year 16 Year 17 Year 18 Year 19 Year 20(13,540)$ (13,811)$ (14,087)$ (14,369)$ (14,656)$ (14,949)$ (15,248)$ (15,553)$ (15,864)$ (16,181)$ (16,505)$ (16,835)$ (17,172)$
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Intermountain Gas CompanyState Street AOINet Present Value
Alternative #Alternative Description Details O&M Cost Used for NPV Net Present Value Year 0 Year 1 Year 2 Year 3 Year 4 Year 5 Year 6 Year 7
N/A State Street Phase II Uprate ($836,769.32)(902,000)$ 4,208$ 4,293$ 4,378$ 4,466$ 4,555$ 4,646$ 4,739$
Year 8 Year 9 Year 10 Year 11 Year 12 Year 13 Year 14 Year 15 Year 16 Year 17 Year 18 Year 19 Year 204,834$ 4,931$ 5,029$ 5,130$ 5,233$ 5,337$ 5,444$ 5,553$ 5,664$ 5,777$ 5,893$ 6,011$ 6,131$
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Intermountain Gas CompanyAda County AOINet Present Value
Alternative #Alternative Description Details O&M Cost Used for NPV Net Present Value Year 0 Year 1 Year 2 Year 3 Year 4 Year 5 Year 6 Year 7
N/A 12 inch South Boise Loop ($17,163,193.12)(17,900,000)$ (10,724)$ (10,938)$ (11,157)$ (11,380)$ (11,608)$ (11,840)$ (12,077)$
Year 8 Year 9 Year 10 Year 11 Year 12 Year 13 Year 14 Year 15 Year 16 Year 17 Year 18 Year 19 Year 20
(12,318)$ (12,564)$ (12,816)$ (13,072)$ (13,333)$ (13,600)$ (13,872)$ (14,150)$ (14,433)$ (14,721)$ (15,016)$ (15,316)$ (15,622)$
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Intermountain Gas CompanySun Valley Lateral AOINet Present Value
Alternative #Alternative Description Details O&M Cost Used for NPV Net Present Value Year 0 Year 1 Year 2 Year 3 Year 4 Year 5 Year 6 Year 7
N/A Compressor
Year 8 Year 9 Year 10 Year 11 Year 12 Year 13 Year 14 Year 15 Year 16 Year 17 Year 18 Year 19 Year 20
(188,677)$ (192,451)$ (196,300)$ (200,226)$ (204,231)$ (208,315)$ (212,481)$ (216,731)$ (221,066)$ (225,487)$ (229,997)$ (234,597)$ (239,289)$
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Intermountain Gas CompanyIdaho Falls Lateral AOINet Present Value
Alternative #Alternative Description Details O&M Cost Used for NPV Net Present Value Year 0 Year 1 Year 2 Year 3 Year 4 Year 5 Year 6 Year 7
N/A
Year 8 Year 9 Year 10 Year 11 Year 12 Year 13 Year 14 Year 15 Year 16 Year 17 Year 18 Year 19 Year 20
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Intermountain Gas Company
Transmission O&M Cost per Mile per Year
From Accounting Records From FERC Form 2 From FERC Form 2
Sub Account Description 2022 2021 2020 3-Year Average
Operation Expense:
28520 Communication System Expenses 24,308.33 30,703.63$ 33,366.62
28560 Mains Expenses 1,793.54 1,805.21 2,088.74
Maintenance Expense:
28630 Maintenance of Mains 125,200.04 26,172.53 12,617.11
28631 Maintenance of Mains 142,328.11
28660 Maintenance of Communication Equip 139,601.91 131,969.39 139,345.50
Total 290,903.82$ 190,650.76$ 329,746.08$
Total Miles of Transmission Line 284 279.49 279.5
O&M Cost per Mile 1,024.31$ 682.14$ 1,179.77$ 962.07$
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Intermountain Gas Company
Distribution Main O&M Cost per Mile per Year
From FERC Form 2 From FERC Form 2
Sub Account Description 2022 2021 2020 3-Year Average
Distribution O&M Expenses 25,445,520$ 24,742,508$ 21,886,836$
28920 Less: Maintenance of Services (3,084,202)$ (3,604,219)$ (2,669,868)$
28930 Less: Maintenance of Meters and Ho (1,350,994)$ (988,180)$ (864,005)$
Total Distribution O&M Expenses 21,010,324$ 20,150,109$ 18,352,963$
Total Miles of Distribution Line 7,155.00 6,970.00 6,560.63
O&M Cost per Mile 2,936.45$ 2,890.98$ 2,797.44$ 2,874.96$
Distribution Main - Miles 6,816.95 6,672.99 6,560.63
Distribution Main - Feet 35,993,509.46 35,233,380.88 34,640,215.45
Service Lines - Miles 6,217.76 6,109.16 5,985.18
Service Lines - Feet 32,829,755.26 32,256,385.40 31,601,800.99
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Intermountain Gas CompanyCompressor Station Operations and Maintenance Estimate
Jerome Description Frequency (Yrs)Unit Price Annualized Cost NotesAnnual Service Overhaul 1 $15,000 $15,000 materials, labor and travel 15K Jerome 25K ShoshoneMisc Repair 2 $2,500 $1,250 example: Bettis actuator failure in 2016/2017, starting system repair 2020, Every 8000 hr Maintenance 10 $60,000 $6,000 est cost and frequencyOil Change 2 $1,200 $600 est cost and frequencyEmissions Test 3 $6,000 $2,000 3 year requirementMisc Maintenance 1 $5,000 $5,000 land, fence, paint, electricity *added 2900 budgeted amount electricity*
Weekly Check (winter)1 $8,960 $8,960 1 Operators for 4 hrs a week for 4 monthsMonthly Startup (Fall, winter, Spring)1 $20,160 $20,160 2 Operators for 8 hrs a month for 9 months Monthly Check (non-winter)1 $3,360 $3,360 1 Operator for 8 hrs a month for 3 monthsPeak Shaving Operators 1 $11,200 $11,200 2 Operators for 8 hrs a day for 5 days a year…Peak Shaving Operators STBY 1 $20,520 $20,520 1 Operators for 18 hours per week per CWE (2022-23 was 76 days) 50/50 Jerome and SSTest Run - NG Fuel 1 $822 $822 6 hr/month for 9 months at 50 th/hr and $0.50/th (WACOG cost of gas 2023) *updated with budgeted amounts fy'21*Peak Shaving - NG Fuel 1 $1,827 $1,827 5 days at 24 hrs/day and 50 th/hr at $0.50/th (WACOG cost of gas 2023)
Estimated Total Annual Costs: $96,700
Shoshone Description Frequency (Yrs)Unit Price Annualized Cost NotesAnnual Service Overhaul 1 $25,000 $25,000 materials, labor and travel Misc Repair 2 $10,000 $5,000 example: Bettis actuator failure in 2016/2017, starting system repair 2020, Every 8000 hr Maintenance 10 $60,000 $6,000 est cost and frequencyOil Change 2 $6,000 $3,000 est cost and frequencyEmissions Test 3 $6,000 $2,000 3 year requirement Misc Maintenance 1 $5,000 $5,000 land, fence, paint, electricity *added 3000 budgeted amount electricity*
Weekly Check (winter)1 $17,920 $17,920 1 Operators for 8 hrs a week for 4 monthsMonthly Startup (Fall, winter, Spring)1 $20,160 $20,160 2 Operators for 8 hrs a month for 9 months Monthly Check (non-winter)1 $3,360 $3,360 1 Operator for 8 hrs a month for 3 monthsPeak Shaving Operators 1 $33,600 $33,600 2 Operators for 8 hrs a day for 15 days a year…Peak Shaving Operators STBY 1 $20,520 $20,520 1 Operators for 18 hours per week per CWE (2022-23 was 76 days) 50/50 Jerome and SSTest Run - NG Fuel 1 $2,960 $2,960 6 hr/month for 9 months at 180 th/hr and $0.50/th (WACOG cost of gas 2023) *updated with budgeted amounts fy'21*Peak Shaving - NG Fuel 1 $19,735 $19,735 15 days at 24 hrs/day and 180 th/hr at $0.50/th (WACOG cost of gas 2023)
Estimated Total Annual Costs: $164,255
*Assumed Operator salary is $140/hr loaded
Wapello Compressors (2 as of 2024)Description Frequency (Yrs)Unit Price Annualized Cost NotesAnnual Service Overhaul 1 $40,000 $40,000 materials, labor and travel 20K each engineMisc Repair 2 $50,000 $25,000 example: Valve repairs, or computer tuning, or safety deviceEvery 8000 hr Maintenance 10 $60,000 $6,000 est cost and frequencyOil Change every 2,000 hours 5 $6,000 $1,200 est cost and frequencyEmissions Test 3 $10,000 $3,333 3 year requirement unless extension is grantedMisc Maintenance 1 $8,000 $8,000 land, fence, paint, electricity *added 3500 budgeted amount electricity*
Weekly Check (winter)1 $35,840 $35,840 2 Operators for 8 hrs a week for 4 monthsMonthly Startup (Fall, winter, Spring)1 $20,160 $20,160 2 Operators for 8 hrs a month for 9 months Monthly Check (non-winter)1 $3,360 $3,360 1 Operator for 8 hrs a month for 3 monthsPeak Shaving Operators 1 $31,360 $31,360 2 Operators for 8 hrs a day for 14 days a year…assuming the compressor will run every yearPeak Shaving Operators STBY 1 $45,360 $45,360 1 Operators for 18 hours per week per peak shaving times of Dec - FebTest Run - NG Fuel 1 $17,542 $17,542 6 hr/month for 9 months at 200 th/hr and $0.50/th (WACOG cost of gas 2023)*updated with budgeted amounts fy'21*Peak Shaving - NG Fuel 1 $20,466 $20,466 14 days at 24 hrs/day and 200 th/hr at $0.50/th (WACOG cost of gas 2023)
Estimated Total Annual Costs: $257,621
*Assumed Operator salary is $140/hr loaded
$518,576Idaho Estimated Total Annual Costs for 4 Compressors
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