Document jyEQ4Z9rO5kzRXkv0Mb7jN2q2

TALEN (>1 MONTANA As reflected above, B&M's estimates of annualized costs are significantly higher than EPA's 538M estimates'-' for a new FF at Colstrip, ranging from 541.7M to $104.9M (using B&M's Class 5 Estimate) and 536.6M to $90.3M (using EPA's approach), assuming that Colstrip is just able to meet the proposed 0.010 lb/MMBtu fPM limit. Further, the cost effectiveness of each of the control options that B&M evaluated arc below, where the first B&M column is based on a IPM baseline of 0.022 lb/MMI3tu, which represents Colstrip's average fPM emission rate in 2022, and the second B&M column is based on a fPM baseline of 0.0195 lb/MMBtu, which represents the average of the EPA's fPM baselines for Colstrip's Units 3 and 4. The B&M estimates arc calculated using EPA's cost approach." Table 5: Cost Effectiveness of Control Options at Colstrip Baghouse c. Upstream ESP Le.: Upstream FF a Wet ESP L) Reheat ESP Reheat FF EPA's $39,192/ton B&M 0.022 lb/MMBtu JPM baseline B&M 0.0195 lb/MMBtu fPM baseline S 1 14,900/ton 5103,200/ton S133,100/ton 553,900/ton 573,200/ton 5 I 45,000/ton . S I 30,300/ton 5168,000/ton $68,000/ton $92,400/ton As reflected above, the cost effectiveness for Colstrip to install the various controls are significantly higher than EPA's estimate of $39,192/ton (see Section 11I.A.2.c, assuming baseloaci operation), ranging from 573,156/ton to $133,104/ton (using the actual 0.022 lb/MMI3tu fPM baseline) and from S68,114/ton to 5168,132/ton (using an average of EPA's fPM baseline for the units). In the B&M scenarios, the cost per ton is calculated assuming that the units will just be able to achieve 0.010 lb/MMI3tu after controls based on the technical review to date, as opposed to EPA's unrealistic assumptions of a 90% reduction in f-PM down to 0.002 lb/MMBtu. At this preliminary stage, the downstream ("Reheat") options are the most cost-effective. The upstream options, and wet ESP option, are even more costly, and come with additional technical challenges, as outlined in the B&M memorandum attached as Attachment C. Despite the lower cost of the Reheat ESP compared to the Reheat IT, the Reheat ESP comes with more technical challenges in meeting the 0.010 lb/MMBtu standard.66 The Reheat FF has fewer technological challenges and could be the preferred alternative should Colstrip retrofit to comply with the Proposal. However, with an annualized cost of 556.5 M (using B&M's Class 5 estimates) " Note that HPA fails to provide mcaningful information as to how annuali7cd control costs wcrc estimated, how capital costs wcrc spccificallv calculated for Colstrip, or what specific control configurations were accounted for in the estimates 1I- his has made it difficult for 11-alcn Montana to fully comment on 1-.PA's cost estimates .S.upret fn 61. See Attachment See Attachment C 20 Sierra Club FOIA 2025-EPA-04883 ED_018388_00000307-00021 SC_EVERSPLIT0006117