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HomeMy WebLinkAbout20260827APPLICATION.pdf RECEIVED August 27, 2026 IDAHO PUBLIC UTILITIES COMMISSION ATEANTA ATL-E-26-01 POWER Atlanta Power Company Wildfire Mitigation Plan Page 1 Table of Contents ExecutiveSummary............................................................................................................................3 Purpose of the Wildfire Mitigation Plan...................................................................................................3 Section1 —Utility Overview..............................................................................................................4 Section 2—Geographical Risk Assessments..................................................................................5 2.1 —General Description of Service Territory and Risk Factors....................................................5 2.2—Risk Tier Methodology and Map............................................................................................5 2.3—Consideration of the Wildland-Urban Interface(WUI)................................................................7 Section 3—Preventative Actions and Programs..........................................................................7 3.1 —Current Status of Preventative Actions and Programs............................................................7 3.2—Additional System Hardening Equipment...............................................................................8 3.3—Deficiency Classification and Prioritization...................................................................................9 Section 4—Public Outreach and Engagement.............................................................................9 4.1 —General Communication Channels and Wildfire Outreach.....................................................9 4.2—Customer Communication Regarding De-Energization.............................................................10 Section 5—Government Outreach................................................................................................10 Section6—Method of Line Design................................................................................................10 6.1 —General Line Design and Construction Standards................................................................10 6.2—Construction Standards for Heightened Risk Areas....................................................................11 Section 7—Situational Awareness and Monitoring..................................................................11 7.1 —Weather and Fire Danger Monitoring Systems.....................................................................11 7.2—Integration into Operations...................................................................................................11 7.3—Enhanced Monitoring Frequency During Heightened Risk.......................................................12 Section 8—Infrastructure Inspections,De-Energization,and Vegetation Management............12 8.1 —Applicable Inspection and Vegetation Management Standards............................................12 8.2—De-Energization: Scope, Standards,and Restoration Protocol.............................................13 8.3—Heightened Fire Risk Area,Vegetation Management and Risk Tree Program.......................13 Section 9—WMP Expenditures and Cost-Benefit Analysis....................................................14 9.1 —Three-Year Expenditures Summary......................................................................................14 9.2—Cost-Benefit Analysis......................................................................................................................14 AdditionalFiling Requirements.....................................................................................................16 Attachment 1 -Notice of WMP Filing(WSCA § 61-1804(2).............................................................16 Page 2 Executive Summary Atlanta Power Company is a small, investor-owned electric distribution utility serving the isolated mountain community of Atlanta,Idaho, in Elmore County. The Company's entire 3.0-square-mile service territory is surrounded by the Boise National Forest and falls entirely within the Wildland-Urban Interface. Atlanta Power's system consists of approximately 6.0 miles of overhead distribution line operating at 2.4 kv. Atlanta Power is committed to proactive wildfire risk reduction. The utility is currently undertaking three significant infrastructure initiatives that constitute its primary mitigation strategy: (1)the ongoing relocation of Atlanta Power's distribution lines from forested areas to roadways, (2) a systematic replacement of aged poles and conductors with new infrastructure throughout the 6-mile system, and(3) a yearly system-wide vegetation management program. Purpose of the Wildfire Mitigation Plan This Plan explains how Atlanta Power designs,inspects, operates,and maintains its electrical system to reduce wildfire risk. It also covers how the Company coordinates with agencies like the U.S. Forest Service and the Atlanta Fire District on wildfire preparedness and emergency response, and how it keeps customers informed of wildfire risks and outages before, during, and after fire season. This Plan addresses system hardening,construction, inspections, and vegetation management in Sections 3 and 8. Page 3 Section 1 — Utility Overview Utility Name Atlanta Power Company Service Territory Size(sq TOTAL: 3.0 miles) Service Territory Make-up <1%Urban (Note:data are from the 5%Barren/Other national land cover database at 85%Evergreen and Mixed Forests USGS.gov;not all categories 9% Shrub are represented in this template) 1%Water Service Territory Wildland- TOTAL: 100%of the Company's service territory falls within the WUI Urban Interface(based on boundary,consistent with the WUI methodology described in Section total area) 2.3 of this plan. Utility Equipment Make-up Overhead Distribution: 6 miles of 2.4 kV (circuit miles) Have protocols been No developed to pre-emptively shut off electricity in response to elevated wildfire risks? Has electricity previously No been pre-emptively shut off in response to elevated wildfire risk? Page 4 Section 2 — Geographical Risk Assessments 2.1 — General Description of Service Territory and Risk Factors Atlanta, Idaho, is an isolated mountain community surrounded by the Boise National Forest, at roughly 5,400 feet elevation near the headwaters of the Middle Fork of the Boise River. The terrain is steep canyon country with dense surrounding timber,matching the 85%evergreen and mixed forest land cover reported in Section I. During fire season,more than one route provides access into and out of the community;however, all these routes remain unimproved dirt roads that continue to limit access, a factor relevant to both wildfire risk and emergency response. Together,these conditions place the Company's entire service territory within a Wildland-Urban Interface intermix zone,described further in Section 2.3. 2.2 — Risk Tier Methodology and Map Atlanta Power sorts all overhead electric facilities in its Idaho service territory into four risk tiers,based on a composite score covering vegetation, fuel load and type,historical fire occurrence,terrain and slope, sustained wind exposure, and structure density. As Section 2.3 explains, 100%of the Company's service territory sits within the Wildland-Urban Interface(WUI), so WUI status alone doesn't differentiate risk here the factors above do that work instead. Tier assignments also shift with the season: because wildfire risk rises during fire season, each area's baseline classification moves up one tier during that period,matching the enhanced monitoring and inspection practices in Sections 4.3 and 7.3. Each tier's baseline(non-fire-season)and fire-season classification is defined below: • Tier 1 —Extreme: The Company's 1.5-mile Heightened Fire Risk Area(see Section 8.3)during fire season, subject to the heightened inspection,vegetation management, and operational practices in Sections 6 through 8. Outside fire season,this same 1.5-mile area is Tier 2 (see below). • Tier 2—Elevated: (a)the Company's 1.5-mile Heightened Fire Risk Area outside fire season(its baseline classification, see Tier 1 above); and(b)the remainder of the system(approximately 4.5 miles)during fire season,when its baseline Tier 3 classification(see below)moves up one tier. • Tier 3—Moderate: The remainder of the system(approximately 4.5 miles)outside fire season. This is the baseline,non-fire-season tier for this portion of the system, and the floor tier for the system overall(see Tier 4 below). It moves up to Tier 2 during fire season(see above). • Tier 4—Low:Not applicable,due to the Company's entire 3.0-square-mile service territory sits within the WUI and is immediately adjacent to forested terrain(see Sections 1 and 2.3); no part of the system qualifies for the lowest risk tier. Tier 3 is therefore the lowest risk classification present on the system. Page 5 Figure 2-1,below, shows these risk tiers geographically across the Company's Idaho service territory, color-coded by tier and cross-referenced to the mileage figures cited elsewhere in this Plan(e.g.,the 1.5- mile Heightened Fire Risk Area boundary discussed in Section 8.3). 0 NIF, • • R D D2 ' s Main Line Project aPn SJ•1 F!1DC, 5 • O Pine Street Project e e Upend w """'''" "'^�^' • - Mine Hill Projectsa • • e • - e ........,,,,� Fire Mitigation Plan Legend Red----------Heightened Fire Risk Area E 0 Blue------Relocation Projects Completed esr:io------------Future We Relocation bmm Figure 2-1 shows the Company's full system, color-coded per the map's legend.Red segments mark the Company's 1.5-mile Heightened Fire Risk Area(Tier 1 &2, see Sections 2.2 and 8.3), combined across multiple segments of the system. Blue segments mark the three completed line relocation projects,labeled on the map: Main Line Project(Main Line into Town),Pine Street Project, and Mine Hill Project(Mine Hill Rebuild),each described in Section 3.2. The orange segment marks the planned future line relocation connecting the community school to Mine Hill junction, currently in the planning stage(see Section 3.1). Areas not marked in red are standard Tier 3 baseline (see Section 2.2). This risk assessment is reviewed and updated annually with each WMP filing to reflect updated fire history,vegetation conditions, and any changes to the Company's facilities. Page 6 2.3 — Consideration of the Wildland-Urban Interface (WUI) Section 1 reports that 100%of Atlanta Power's service territory falls within the Wildland-Urban Interface. Given the Company's small footprint(3.0 square miles)and land cover dominated by evergreen and mixed forest(85%), structures throughout the territory are intermixed with wildland vegetation rather than simply bordering it. That matches the WUI Intermix pattern in national WUI mapping methodologies(e.g.,the U.S. Forest Service SILVIS Lab classification),where development is interspersed within wildland vegetation with no clear dividing line,unlike the WUI Interface pattern of a development edge bordering a larger, contiguous block of wildland. Because the entire service territory is uniformly WUI,that status alone doesn't further differentiate risk within the Company's tier approach in Section 2.2: every foot of the system already reflects the elevated consequence of structures embedded in wildland vegetation. Instead,the Company differentiates risk tiers using the factors in Section 2.2 (vegetation fuel load,historical fire occurrence,terrain and slope, sustained wind exposure, and structure density), each of which varies across the territory even though WUI classification does not. The 100% WUI figure comes from the Company's review of the ArcGIS WUI Viewer, a GIs mapping tool built on the federal WUI dataset(U.S. Census housing density combined with USGS National Land Cover Data, following the Federal Register definition of WUI). That tool shows the town of Atlanta and the surrounding service territory entirely within a mapped WUI zone, confirming the Intermix characterization above. Section 3 — Preventative Actions and Programs 3.1 — Current Status of Preventative Actions and Programs This section covers preventative-action and program activity currently underway or completed,before turning to planned equipment upgrades (Section 3.2)and the Company's deficiency prioritization standards(Section 3.3). To date,the Company has completed three system hardening projects,addressing a combined 3,400 feet of aging line (since replaced with a combined 4,000 feet of new line,reflecting the longer road-following alignments used for the two relocation projects)with deficiencies matching the priority classifications in Section 3.3: rotted poles,mechanical connectors, deteriorated wooden cross arms,and leaning poles. Two projects relocated line segments out of forest canopy(in one case, out from over buildings) into road right-of-way;the third rebuilt an aging segment in place within the forest right-of-way. These are the Pine Street and Main Line into Town line replacement and relocation projects and the Mine Hill Rebuild, all described in Section 3.2. Beyond these three completed projects,the Company is planning a line extension connecting the community school to Mine Hill junction. The existing 900-foot segment runs through meadow and forest vegetation and shows rotted poles,mechanical connectors, and aging cross arms,the same deficiency criteria from Section 3.3 found in the Company's completed relocation projects, and forms part of the approximately 1 mile of system-wide aging infrastructure described in Section 6.1. This project will move the line to the adjacent road right-of-way, following the realignment strategy in Section 3.2,replacing the existing 900 feet with approximately 600 feet of new line. The Company anticipates beginning this Page 7 project in approximately November 2026; the completion date has not yet been determined. Capital and labor cost estimates are not yet available because the project is still in the early stage of planning. 3.2 —Additional System Hardening Equipment Line Realignment Out of Forested Rights-of-Way: Several of the Company's existing distribution lines were originally built on a direct, cross-country path through forested terrain,chosen at the time to minimize span length and construction cost.Where feasible,the Company is now relocating these legacy segments to follow existing road rights-of-way instead. This cuts the line's exposure to dense timber fuel loads and overhanging or leaning trees, gives crews year-round vehicle access for inspection, maintenance, and fire suppression, and shrinks the vegetation-management corridor that would otherwise need to be maintained through forest canopy. Completed Project—Pine Street Line Replacement and Relocation: The Company has completed relocation of the Pine Street line segment,previously routed on a direct,roughly 700-foot alignment through open meadow and forest canopy,with rotted poles,mechanical connectors, and deteriorated wooden cross arms with wooden pins. It's now been replaced and relocated with approximately 1,100 feet of new,upgraded powerline(new poles,new conductor, and pressed connectors)within the adjacent road right-of-way. The segment is about 400 feet longer than before but moving it out of continuous meadow and forest-canopy exposure and into the road right-of-way, combined with the equipment upgrades, meaningfully cuts vegetation-contact ignition risk and improves year-round vehicle access for inspection, maintenance, and fire suppression. Completed Project—Main Line into Town: The Company has completed replacement of the Main Line serving the town,previously routed on an approximately 1,700-foot alignment through forest canopy and built directly over buildings,with rotted poles,mechanical connectors, and deteriorated wooden cross arms with wooden pins. It's been replaced with approximately 1,900 feet of new,upgraded powerline (new poles,new conductor,pressed connectors)along the road right-of-way, feeding the main intersection of town. Moving this segment out of the forest canopy and away from directly over structures, combined with the equipment upgrades,reduces vegetation-contact ignition risk,removes the hazard of an energized line running directly above occupied buildings,and improves year-round vehicle access for inspection,maintenance, and fire suppression. Completed Project—Mine Hill Rebuild: Unlike the two relocation projects above,this one addresses an aging segment that stays within the forest right-of-way rather than moving to a road right-of-way. The Company completed replacement of an approximately 1,000-foot segment of aging powerline meeting the Priority 1 deficiency criteria in Section 3.3. The segment was rebuilt in place with new poles,new conductors, and pressed connectors,plus bi-directional guying at the poles on each end to improve structural stability and reduce the risk of pole lean or failure. Beyond line realignment,the Company's system hardening program includes replacing or installing the following equipment,where routine inspection or aging asset management identifies it as a wildfire risk mitigation measure: • Polymer(non-ceramic)insulators,rated 12 kV,in place of porcelain insulators subject to flashover or contamination-related failure Page 8 • Current-limiting fuse upgrades to reduce fault energy and arc duration in heightened risk areas • Pressed(compression) connectors in place of mechanical/bolted connectors,reducing the risk of loosening, arcing, and heating at conductor connection points • Bi-directional guying at poles on either side of forest right of way,to improve structural stability and reduce the risk of pole lean or failure 3.3 — Deficiency Classification and Prioritization Deficiencies identified during inspection(see Section 8.1)are classified and corrected under the following three-tier system, applied consistently across all infrastructure types: Priority Definition i i Condition poses an imminent risk of ignition, Priority 1 — electrocution,or other immediate public safety Corrected Immediately Emergency hazard(e.g.,broken/downed conductor,broken pole,tree through powerline) Condition presents an elevated but non-imminent Priority 2— risk(e.g., significant equipment wear, Corrected within 3 to 6 months Priority encroaching vegetation not yet in contact with conductor). Condition does not present a near-term wildfire Priority 3— or safety risk but should be corrected as part of Next scheduled maintenance Routine normal maintenance(e.g.,minor hardware wear, cycle or within 12 to 18 months routine wood pole treatment). Deficiencies in Tier 1 or Tier 2 risk areas(Section 2.2)are corrected within the shorter end of the applicable timeline above,reflecting the heightened consequence of ignition in those areas. Section 4 — Public Outreach and Engagement 4.1 — General Communication Channels and Wildfire Outreach Atlanta Power communicates with its customers through multiple channels.Wildfire mitigation has not historically been a regular topic in that communication,but going forward the Company will fold wildfire mitigation education and outreach into its ongoing customer communications, as described in this Plan. • Direct contact • Social media • Phone services • Bill inserts The Company hasn't yet decided whether to hold a dedicated public comment period or meeting on this WMP for customers, agencies,and other community organizations, and will consider this for future updates. The Company will also share this Plan with the Idaho State Forester,fire protection districts, and Page 9 fire protection associations within its service area, as described in the Notice of WMP Filing later in this document. 4.2 — Customer Communication Regarding De-Energization Because the Company has decided against proactive de-energization(PSPS)as a wildfire mitigation strategy(see Section 3.2),this Plan doesn't include a dedicated de-energization customer communication protocol. If the Company adopts proactive de-energization in a future WMP update,this subsection will be revised to describe the customer notification protocol at that time. Section 5 — Government Outreach Atlanta Power maintains an ongoing working relationship with the Atlanta Fire District for emergency response coordination and coordinates closely with the U.S. Forest Service on wildfire preparedness matters affecting the Company's service territory. This includes daily information sharing between the Atlanta Fire District and Atlanta Power, and joint training between the two organizations. Section 6 — Method of Line Design 6.1 — General Line Design and Construction Standards Outside the heightened wildfire risk areas addressed in Section 6.2,the Company's line design and construction practices follow National Electrical Safety Code(NESC)minimum requirements together with industry-standard practice for a system of this size and voltage class;the Company does not maintain a separate internal engineering or design manual. The Company's distribution system runs at 2.4 kV(see Section 1),and system-wide baseline construction typically uses Class 3 or 4 wood poles,#4 ACSR conductor, and 8-foot wood or fiberglass cross arms with standard porcelain insulators, each meeting or exceeding NESC minimum requirements as described in Section 6.2. These baseline standards are the Company's"Standard Practice"referenced in Table 6-1 of Section 6.2, against which the enhanced construction standards for heightened wildfire risk areas are compared. The Company is transitioning from porcelain to polymer(non-ceramic)insulators,rated at 12 kV, system-wide,matching the equipment upgrade described in Section 3.2. Approximately 1 mile of the Company's system outside the completed projects in Section 3.2 is more than 30 years old,and approximately 28%remains routed through forested areas. This aging infrastructure shows the same kind of conditions corrected in the Pine Street,Main Line into Town, and Mine Hill Rebuild projects: rotted or weathered poles,mechanical(bolted) conductor connectors, deteriorated wooden cross arms secured with wooden pins,and,in some locations, leaning poles. About 16% of the system currently meets the Company's replacement criteria in Section 3.3. The Company identifies and addresses these conditions through the deficiency classification and prioritization process in Section 3.3, and it expects to continue identifying and correcting additional segments through the system hardening program in Section 3.2 as resources allow. Page 10 6.2 — Construction Standards for Heightened Risk Areas New construction,rebuilds,and planned upgrades within the Company's service territory are designed and built to the NESC, 2023 Edition,along with the construction,clearance, and vegetation requirements under the Company's U.S.Forest Service special use permit(s) for rights-of-way on National Forest lands. Under the permit's"Applicable Reliability and Safety Standards"provision,the Company's facilities are subject to the NESC and standards issued by the Occupational Safety and Health Administration(OSHA). NESC construction standards are covered below in Section 8.1, and Company personnel follow applicable OSHA standards for electric power generation,transmission, and distribution work(29 CFR Part 1910.269). Table 6-1 Component d. Practice Heightened Risk Area Practice Pole Type Class 3 or 4 wood pole Full-treat poles used to replace all poles within heightened risk areas Conductor #4 ACSR conductor 12 kV-rated insulators with increased conductor spacing Cross Arms Wood or fiberglass, 8 ft Fiberglass cross arms,utilized in heavily wooded areas where access may be a challenge—see Section 3.2 Hardware/Insulators Porcelain Polymer/non-ceramic, 12 kV—see Section 111.B F Section 7 — Situational Awareness and Monitoring 7.1 — Weather and Fire Danger Monitoring Systems The Atlanta Fire District handles weather and fire danger monitoring for the Company's service territory, and the Company relies on it to track forecasts,current weather conditions, and fire danger. This matches the daily information-sharing relationship between the Atlanta Fire District and Atlanta Power described in Section 5. The Fire District's monitoring tools include NOAA weather data,the Watch Duty wildfire tracking app,and resources from the Western Fire Chiefs Association. 7.2 — Integration into Operations One of the Company's owners' reviews weather and fire-danger information from the Atlanta Fire District daily during fire season.When that review shows elevated wildfire risk,the Company responds with a weekly visual inspection of its system,matching the enhanced monitoring practices in Section 7.3. Because Atlanta Power's service territory is a small, standalone system with no other utility operating nearby,the Company doesn't currently need to monitor for de-energization events from other entities. Page 11 7.3 — Enhanced Monitoring Frequency During Heightened Risk Table 7-1 below defines,numerically,what counts as"increased"or"enhanced"monitoring and inspection frequency in both Section 6.3 (fire season)and Section 7.3 (operational practices during heightened risk), covering both in one place. Table 7-1 Activity Baseline Routine Enhanced(Fire Season Tier I- 2 Areas) Weather/fire-danger monitoring Weekly Daily during fire season(see Section 7.2) Line patrol/visual inspection Monthly Weekly during periods of elevated wildfire risk(see Section 7.2) Not applicable—given the size of the Company's system,a separate Detailed Pole Inspections Annually enhanced Detailed Pole Inspection cycle for heightened risk areas is not maintained beyond the annual baseline cycle Fire weather index/outlook review Same as"Weather/fire-danger Same as"Weather/fire-danger monitoring"row above monitoring"row above None currently in place—the Workforce operating restrictions Standard operating procedures Company does not have formal operating restrictions specific to high-risk days currently Section 8 — Infrastructure Inspections, De-Energization, and Vegetation Management 8.1 — Applicable Inspection and Vegetation Management Standards Infrastructure inspections follow the National Electrical Safety Code(NESC), 2023 Edition.Vegetation management activities in Section 8.3 follow ANSI A300 Parts I (Pruning) and 7 (Integrated Vegetation Management),most current edition.No additional inspection or construction standards apply. Beyond the standards above,vegetation management within the Company's U.S.Forest Service special use permit area(see Section 6.2)is governed by that permit's Operating Plan(Section 7,Vegetation Management). Following the Operating Plan,the Company's vegetation management program aims to(1) maintain reliability, address public safety,and eliminate the risk of vegetation-caused outages; (2) minimize the spread of invasive plant species within the permit area; (3)maintain and enhance vegetation conditions for fish,wildlife,plant,water, and soil resources; and(4)encourage low-growing vegetation where feasible. Page 12 Best management practices under the Operating Plan include compliance with Forest Service National Core BMPs(per the Forest Service's BMP Technical Guide), applicable standards and guidelines in the governing national forest land management plan,and NESC clearance factors under NESC Section 218: line voltage class, species growth rates,vegetation location relative to conductors, and potential conductor sag or movement. The Operating Plan also requires Integrated Vegetation Management(IVM)under ANSI A300,Part 7,matching the citation above; IVM aims to convert right-of-way vegetation to low- growing,non-invasive plant communities. Under the Operating Plan's routine vegetation management provisions,the Company may control vegetation within approximately 30 feet(9 meters)of powerline facilities in the permit area, or a larger perimeter where reliability, electrical,or safety standards require it,with prior written notice to and approval from the Forest Service. In practice,the Company's actual clearance perimeter, described in Section 8.3,is 15 feet,narrower than and within the 30-foot maximum the Operating Plan allows. The Company also follows the Operating Plan's emergency vegetation management provisions,notifying the Forest Service within 24 hours of starting an emergency response and filing a written report within 30 days of completion. 8.2 — De-Energization: Scope, Standards, and Restoration Protocol The Company evaluated proactive de-energization(Public Safety Power Shutoff,or PSPS)as a wildfire mitigation strategy and decided not to adopt it as part of this Plan. Given the small size and limited customer count of the service territory,along with the operational and reliability tradeoffs of proactive shutoffs compared with the system hardening and vegetation management measures already underway elsewhere in this Plan,the Company concluded those measures offer a more effective approach to wildfire risk reduction for its system right now. This decision doesn't affect the Company's existing automatic protective equipment,which will de- energize a line automatically when it detects a fault condition, as a standard part of the Company's overcurrent protection plan and normal utility practice. That automatic function isn't a discretionary wildfire mitigation tool and operates independently of this decision.After any such automatic protective operation, Company personnel visually inspect the entire system before re-energizing to confirm there's no downed conductor,vegetation contact, or other hazard,and that no fire has ignited. The Company will keep evaluating whether proactive de-energization makes sense to adopt in a future WMP update as conditions,technology, or system configuration change. 8.3 — Heightened Fire Risk Area Vegetation Management and Risk Tree Program Within the Company's designated 1.5-mile Heightened Fire Risk Area described in Section 2.2, vegetation management follows an enhanced cycle relative to the Company's routine, system-wide vegetation management program: • Enhanced clearance cycle: Annual trimming happens March through April within the Heightened Fire Risk Area,timed ahead of fire season, clearing vegetation to about 15 feet from powerline facilities,matching the clearance perimeter in Section 8.1. The Company's routine, system-wide Page 13 vegetation management cycle is also annual,but isn't tied to a specific season and is less intensive. The Heightened Fire Risk Area cycle is enhanced in two ways: (1)timing, since clearing is deliberately scheduled for March through April rather than any time during the year; and(2) scope and intensity, since trimming within the Heightened Fire Risk Area is more thorough than the routine cycle,matching the area's elevated risk classification. • Supplemental as-needed trimming: Vegetation conditions identified during any inspection (routine or enhanced)within the Heightened Fire Risk Area are addressed within 30 to 60 days regardless of the annual cycle. Risk trees—trees identified as dead, dying,diseased,or structurally compromised such that they pose a risk of falling into Company facilities—are classified and addressed as follows: • Imminent Hazard: Tree presents an immediate risk of falling into energized facilities. After identification,the Company contacts the customer and plans removal. • Elevated Risk: Tree presents a risk of falling into facilities but is not imminent—scheduled for removal within 60-90 days. The Company considers vegetation management recommendations from the U.S.Forest Service in developing and updating these standards. The Company follows the Operating Plan's general requirements(see Section 8.1)without additional case-specific input beyond those requirements. Measurable Targets: The Company's measurable vegetation management targets for the WMP term are currently under development, and a timeline for establishing them has not yet been determined. Section 9 — WMP Expenditures and Cost-Benefit Analysis 9.1 — Three-Year Expenditures Summary This section provides a full cost breakdown by year for both capital and O&M expenditures, covering the required minimum three-year rolling planning horizon. As of this filing,the Company has not yet developed detailed cost estimates specific to wildfire mitigation activities. It expects to have those ready by the first annual WMP update. 9.2 — Cost-Benefit Analysis The cost-benefit table 9-1 below includes labor costs,not just capital. Wildfire risk-reduction benefits can be shown in narrative form or numerically, as long as the approach stays consistent across projects. Atlanta Power weighs each project's total cost(capital and labor) against its expected wildfire risk- reduction benefit.Where that benefit can be reasonably measured, such as a reduction in ignition risk or miles of exposed bare conductor,the Company shows that estimate. Where it can't be reliably measured, Page 14 the Company describes the risk reduction in narrative form instead,using the same approach across all projects for comparability. Table 9-1 Project/Segment Units Capital Labor Cost Total Cost Risk Reduction Benefit (miles) Cost Pine Street line Removed line from replacement and 0.21 mi continuous meadow/forest- relocation(Section 3.2) (1,100 ft) $10,285.00 $8,415.00 $18,700.00 canopy exposure into road —completed ROW;reduces vegetation- contact ignition risk Removed line from forest- Main Line Into Town canopy exposure and over top replacement and 0.36 mi of buildings into road ROW; relocation(Section 3.2) (1,900 ft) $15,675.00 $12,825.00 $28,500.00 reduces vegetation-contact —completed and structure-overbuild ignition risk Replaced leaning poles and mechanical connectors with Mine Hill Rebuild 0.19 mi new poles, conductor,pressed (Section 3.2)— 000 ft) $7,650.00 $9,350.00 $17,000.00 connectors, and bi-directional completed (1, guying; addresses Priority 1 deficiency criteria (Section 3.3) Beyond the project-specific analysis above, Table 9-2 below provides a high-level assessment of cost against wildfire mitigation impact. Table 9-2 Program/Activity Cost Impact on Wildfire Mitigation Line realignment out of forested ROW High High Pole replacement(system hardening) High Medium Non-wooden cross arms&hardware upgrades Medium Medium Infrastructure inspections Medium Medium Vegetation management High High Public&government outreach Low Low Page 15 ATLANTA POWER Attachment 1 Template Notice August 27,2026 Via Email or Certified Mail Subject: Notice of Filing—Atlanta Power Wildfire Mitigation Plan Dear In accordance with Idaho Code 61-1804(2),Atlanta Power Company hereby notifies you that on August 27, 2026,Atlanta Power filed its Wildfire Mitigation Plan with the Idaho Public Utilities Commission for initial review. The Plan outlines Atlanta Power's operational plan to reduce wildfire risks associated with electrical infrastructure and vegetation management. How to Participate: Atlanta Power's Plan has been filed with the Commission. Copies of the filing are available for public inspection during regular business hours at the Commission's office located at 11331 W. Chinden Blvd. Building 8, Suite 201-A,Boise,ID 83714,or the Commission's website at hgps://puc.idaho.gov/. Click the "ELECTRIC" icon, select"Open Cases," and click Case No._. Interested parties may also subscribe to the Commission's RSS feed to receive periodic email updates about the case. Written comments regarding Atlanta Power's filing can be filed with the Commission; comments must be filed through the Commission's website or by email. To comment electronically,visit www.pub.idaho.gov and click on the "Case Comment Form" link on the upper left side of the page. Please use the case number when filling out the form. To comment using email,please send comments to the email addresses listed below and include the case number. Comments are required to include the commenter's name and address. For the Idaho Public Utilities Commission: Commission Secretary If sending express mail: Idaho Public Utilities Commission 11331 W. Chinden Blvd. Building 8, Suite 201A P. O. Box 83720,Boise,ID 83720-0074 Boise,ID 83714 s ecretarv@puc.idaho.go Respectfully, Nicholas Jones Owner/Operator (208)401-4114 Page 16