Chicago gas capacity: city utility reports 3% coldest-day margin, one storage field supplies 26%

By Sam Strong, Vice President of Business Development, Discovery Energy. Technical review by Tara Dugger, Chief Operating Officer. Updated October 2026.

Metro used: the Chicago-Naperville-Elgin, IL-IN metropolitan statistical area, as the federal government defined it on July 21, 2023.¹ This page reads two gas utilities, The Peoples Gas Light and Coke Company (the City of Chicago) and North Shore Gas Company (northern suburbs), and reports Northern Indiana Public Service Company LLC (NIPSCO) for its whole system, which extends beyond the metro and cannot be assigned to the Indiana counties. Northern Illinois Gas Company (Nicor Gas) is covered on a separate page that gives no outlook level, because its record gives no reserve margin.

Key takeaways

Who serves the Chicago area?

Peoples Gas serves the City of Chicago, with about 885,000 customers, and North Shore Gas serves the northern suburbs, with about 164,000 customers.² The record read does not name the counties North Shore Gas serves.²⁰ The figures on this page cover each utility's whole system. Nicor Gas serves most of the rest of northern Illinois. Its presentation lists 2.28 million customers for its whole system.¹⁸ We do not read its system on this page; its record is on the separate stress record page, which gives no outlook level. NIPSCO serves gas customers in Indiana, and the Indiana Utility Regulatory Commission's order names no county.¹⁹ The public record doesn't show its service in Jasper, Lake, Newton and Porter counties, Indiana, and has no narrower figures, so we report its whole-system figures and do not assign them to the metro. Manlove Field, Peoples Gas's storage field in Champaign County, Illinois, is not in the metro but supplies Peoples Gas and North Shore Gas.²¹ Its share of Peoples Gas's design day counts toward the rating, because it is a share of a metro utility's design day.⁵ Kenosha County, Wisconsin, is not in the federal definition of the metro, and this page reads no record for it.¹⁰⁸

Has Chicago had gas supply problems since 2020?

Peoples Gas documented storage problems at Manlove Field and some pipeline and supplier problems, but its presentation describes no supply shortfall. Peoples Gas said Manlove Field's design day capacity was reduced in 2022 because of continued water disposal issues.¹² It said the field was no longer experiencing the hydrates it had in 2021 and 2022; the testimony gives no month or heating season for either.²² Peoples Gas also said that in 2024 some suppliers failed to deliver the quantity requested, with no overrun or penalty charges as a result.²³ It said that in 2024 Natural Gas Pipeline Company of America (Natural) experienced outages and imposed restrictions.²⁴ Peoples Gas received $715.94 in reservation credits from Natural.²⁵ It incurred $107,847.32 of overrun charges for the year, which the answer does not attribute to a single cause.²⁶ Its presentation reports total deliveries of 82% of its peak day on the December 2022 winter storm and 77% on January 15, 2024.¹³ The records read for North Shore Gas and NIPSCO describe no supply event since 2020, but they are presentations and one gas cost order, not a search of event reports.²⁷

How much spare gas capacity does the Chicago area have on the coldest day?

Both Peoples Gas and North Shore Gas stated a design day reserve margin, and the record gives no coldest-day supply total.

Peoples Gas. In April 2025 testimony on its 2024 gas charge reconciliation, Peoples Gas said its 2024 design day reserve margin for physical supply was approximately 3.00%, a figure it stated for its whole system.³ It defines its design day as a January weekday at -16 degrees Fahrenheit (81 degree days) with a 22 miles per hour wind.²⁸ It said the margin was necessary in part because it is near the end of the facilities of Natural and Northern Border Pipeline Company.²⁹ Its detailed design day calculation is in its response to Staff data request ENG 1.17, which was not among the documents read.³⁰

Firm capacity each utility holds on each pipeline, in dth (dekatherms, a unit of gas energy) per day, from the September 2024 presentation.³¹ The presentation says Peoples Gas and North Shore Gas interconnect with nine interstate pipelines, with Peoples Gas contracting firm capacity on five and North Shore Gas on three.³² Peoples Gas's winter 2023-24 peak day plan shows baseload at 12%, daily purchases at 4%, storage withdrawals at 75% and third party deliveries at 9% of the plan.⁸ In the September 2024 presentation, Manlove Field's underground storage supplies 27% and its LNG facility 15% of Peoples Gas's peak day requirement.³³ The April 2025 testimony gives the field's share of the 2024 design day as about 26%.⁷ Peoples Gas said its LNG facility, part of the Manlove Field complex, was not used in 2024 to support daily or hourly deliveries.³⁴ The December 2024 presentation says Manlove Field is responsible for 41% of the Peoples Gas peak day plan.³⁵ The slide does not say whether that includes the LNG facility, so the figures are not reconciled here.³⁶ Neither Figure 1 nor the table gives a coldest-day supply total, so we make no calculation of spare capacity beyond the stated margin. North Shore Gas. North Shore Gas buys a storage service from Peoples Gas under a Commission-approved contract, and the two systems are not physically interconnected.³⁹ Its April 2025 testimony says that service accounts for 14% of its peak day demand and about 11% of its annual storage capacity portfolio.¹⁴ The September 2024 presentation says Manlove Field underground storage supplies 14% of its peak day requirement and 10% of its winter volume.⁴⁰ In its own 2024 gas charge reconciliation testimony, North Shore Gas said its 2024 design day reserve margin for physical supply was approximately 3.00%, a figure it stated for its whole system.⁴ It defines its design day as a January weekday at -19 degrees Fahrenheit (84 degree days) with a 22 miles per hour wind.⁴¹ It said the margin was necessary in part because it is located near the end of the facilities of Natural and ANR.⁴² It also said that releasing 16,114 dth per day of Natural capacity for November 2024 to March 2025 helped bring the margin closer to its targeted level of 3%.⁴³ Its design day calculation is in its response to Staff data request ENG 1.17, which was not among the documents read.⁴¹ The testimony read states no design day total. Nicor Gas. Nicor Gas's September 2024 presentation lists a design peak day for its whole northern Illinois system.⁴⁴ Its record read gives no supply total or reserve margin, so the public record doesn't show its spare capacity. NIPSCO (Indiana). The Indiana Utility Regulatory Commission's May 2024 order summarizes NIPSCO testimony that its peak season firm pipeline contracts with six pipelines total approximately 789,000 Dth per day after allocations to Choice suppliers.¹⁷ It also summarizes testimony that NIPSCO's contracted storage can withdraw approximately 512,000 Dth per day.⁴⁵ The order says NIPSCO also owns underground storage and LNG storage of 4,000,000 Dth each.⁴⁶ These are whole-system figures, and the order gives no design day or margin.

What is driving new natural gas demand?

The largest new gas load found in the records read for the metro is in Indiana. It does not change the rating, because the orders give no in-service date for the units, no gas volume, no pipeline and no remedy to compare.⁶² We found no new gas load on the Peoples Gas or North Shore Gas systems. The Indiana Utility Regulatory Commission approved on June 17, 2026 gas-fired generation for one data center customer of NIPSCO.⁴⁷ NIPSCO Generation LLC (GenCo) is converting two pairs of combustion turbines at the Schahfer Generating Station in Jasper County, Indiana to combined cycle units, for 2,600 MW (megawatts, a unit of electric generating capacity) of generating capacity.⁴⁸ GenCo expected to begin construction in the second quarter of 2026.⁴⁹ The Indiana commission approved the special contract and the power purchase agreement the same day.⁵⁰ Its order says 3,000 MW of new capacity will be built to serve an estimated 2,400 MW of electric load.⁹⁸ NIPSCO's witness said its gas system has multiple interconnection points with seven interstate pipelines.⁵¹ A witness for the NIPSCO Industrial Group recommended a study of whether the planned gas supply arrangements would affect interstate pipeline capacity or NIPSCO's gas transmission system, and NIPSCO said it would study the gas usage and identify system impacts.⁵² The order summarizes NIPSCO's statement that upgrade costs would be charged or allocated to GenCo.⁵⁴ The orders state no in-service date for the combined cycle units, no gas volume and no pipeline.¹⁶ A separate natural gas combustion turbine plant of about 400 MW at the same site was certificated on October 16, 2024.⁵⁵ It is expected to be in service by the end of 2027 and needs a 1,500-foot lateral to NIPSCO's gas system.⁵⁶ The U.S. Energy Information Administration (EIA) publishes a monthly inventory of generators; its September 2026 inventory, still its latest, lists four planned turbines at the Schahfer site, 383.2 MW, planned for December 2027, with approvals received and the units not under construction.⁵⁷ The orders and the inventory do not say whether the four turbines are the 400 MW plant, so the public record doesn't show whether they are. The same inventory lists two engines at the ITT Cogen Facility in Cook County, Illinois, 8.2 MW, planned for March 2027 and under construction.⁵⁸ It does not name the gas utility that would serve them or call them a data center load. The Midcontinent Independent System Operator's public interconnection queue (its list of power plants waiting to connect to the grid), saved October 27, 2026, lists 27 entries in the 13 metro counties.⁵⁹ Two of these are gas entries in Jasper County, both withdrawn, and none is active.⁶⁰ A search of Federal Register notices from the Federal Energy Regulatory Commission (FERC) since January 2025 for each of the 13 counties returned none.⁶¹ A FERC notice of September 9, 2026 lists GenCo as an exempt wholesale generator, which concerns electric service, not gas.¹⁰¹ The PJM interconnection queue, Illinois EPA air permits and Illinois and Indiana economic development filings were not reviewed for this page.⁶³ Data centers: As of October 28, 2026, we found no gas special contract, pipeline lateral or large-load tariff for a data center for Peoples Gas, North Shore Gas or NIPSCO in the sources reviewed, but the Commission's online docket and the Indiana commission's online services could not be reviewed, so filings there may not be reflected.¹⁰² The Indiana order says the generation serves Amazon Data Services, Inc. (Amazon), whose service is expected to begin by January 1, 2027, with its load requirements increasing through the end of 2032 to up to 2,400 MW.¹⁵ Nearby: Two pipeline expansion filings cross the metro's counties, and neither says its gas reaches Peoples Gas or North Shore Gas. Guardian Pipeline's Guardian 3 Expansion Project, filed July 1, 2026, would add about 536,903 dth per day of firm capacity, with Illinois facilities in Kendall, DeKalb, McHenry and Will counties.¹⁰⁵ Guardian's August 2026 fact sheet says five gas distribution companies support the project; it does not name them or mention data centers.¹⁰⁶ On August 12, 2026, Natural filed for a North Extension Project that would add 185,000 dth per day of firm service for Wisconsin Electric Power Company, with new compression in Lake and Will counties, Illinois and an 11.5-mile lateral to Kenosha County, Wisconsin.¹⁰⁷

Are upgrades arriving in time?

The record read names no approved or scheduled capacity project for Peoples Gas, North Shore Gas or NIPSCO, and no filed long-term gas infrastructure plan was among the documents read for them. The Commission's 2023 order directed Peoples Gas and North Shore Gas to file one every two years beginning in July 2025.⁶⁴ A July 2024 workplan outlined a supply analysis for 2026 to 2030 with a peak day resource mix.⁶⁵ The Appellate Court later vacated that requirement (see 'Policy context').⁶ Peoples Gas said no significant change to its transportation and storage portfolio affected 2024.⁶⁶ Nicor Gas's May 2025 near-final plan presentation lists storage, transmission and distribution projects over $5 million for 2026 to 2030 and gives no capacity addition.⁶⁷

Winter and market context

Regional conditions. Illinois and Indiana are in EIA's Midwest storage region, where working gas was 1,065 billion cubic feet for the week ending October 16, 2026, in EIA's weekly table released October 22, 2026; we did not read the five-year comparison EIA states in its weekly report.⁷³ National conditions and commodity prices, which are not evidence of a constraint, are given in the note to this sentence.¹¹¹ Pipeline notices. ANR Pipeline Company ("ANR") posted five cold weather episodes in winter 2025-26.⁷⁸ It also issued an order telling shippers to keep their gas flows in balance.⁷⁹ Northern Border Pipeline Company ("Northern Border") limited its Des Plaines delivery point (where the pipeline hands gas to the utility) to primary only for gas day January 24, 2026.⁸⁴ Natural posted capacity constraint and other notices, and Kinder Morgan Illinois Pipeline one gas quality notice.⁷⁶ None names a delivery point of Peoples Gas, North Shore Gas or Nicor Gas, so the public record doesn't show which events reached a utility in the metro. Six other pipelines' notice pages could not be read.⁸⁷ ANR's notices begin only in October 2025.⁸⁵

Winter weather and NOAA's outlook

Heating degree days (a measure of how cold the weather was) at the Chicago O'Hare International Airport weather station, from November to March, were below the 1991-2020 normal in winters 2023-24, 2024-25 and 2025-26.¹⁰³

Heating degree days, November to March, with the share of the 1991-2020 normal in brackets.¹¹⁰ NOAA's Climate Prediction Center outlooks issued October 15, 2026 lean toward warmer than normal for the Chicago area for November 2026 to January 2027 and December 2026 to February 2027, but they are probabilities for a three-month average, not forecasts of specific days.¹⁰⁴

Policy context

The Commission's November 16, 2023 order directed Peoples Gas and North Shore Gas to file a long-term gas infrastructure plan every two years beginning July 1, 2025.⁶⁴ On January 21, 2026 the Commission reopened the case to rescind that direction.⁸⁸ Its April 9, 2026 order says the Illinois Appellate Court, Second District, vacated the directive on March 10, 2026, finds the reopening moot and closes the docket, and quotes the Third District's December 1, 2025 decision vacating the corresponding plan for Nicor Gas.⁶ The Illinois Capital Development Board says the 2024 edition of the International Energy Conservation Code, as amended, went into effect on November 30, 2025.⁹⁰ It says the 2023 Illinois Stretch Energy Code went into effect on January 1, 2025 and applies to privately funded commercial facilities where the local municipality has adopted it.⁹¹ The pages read do not mention natural gas, and they do not say which municipalities in the metro have adopted the stretch code.

What is the outlook for Chicago-area gas capacity through 2029?

Discovery Energy rates the outlook for Chicago-area natural gas capacity through 2029 as High (confidence: Medium): the stated 2024 design day reserve margins for physical supply of Peoples Gas and North Shore Gas are both below the 5% thin-margin threshold with no approved or scheduled fix in the record read, and two documented risk factors raise the base level of Elevated by one step.⁹² Documented risk factors: concentration (F1), because Manlove Field storage supplied a large share of the Peoples Gas design day; and a recent event (F3), because Peoples Gas documented water disposal issues at Manlove Field in 2022, hydrates there in 2021 and 2022, and pipeline outages and supplier delivery failures in 2024.⁹³ Three developments would change the assessment: Peoples Gas's or North Shore Gas's responses to the Staff data request on the design day calculation, or their next annual gas charge reconciliations, showing an updated margin or Manlove Field share; a change in Manlove Field's design day capacity, a new dated event, or an approved or scheduled supply fix; and a filing-confirmed in-service date, gas volume or pipeline for the GenCo combined cycle units or the 400 MW plant at the R M Schahfer site in Jasper County, Indiana. This outlook level rests on the stated margins of Peoples Gas and North Shore Gas. The NIPSCO record read gives no reserve margin or supply-versus-requirement figure, so it neither raises nor lowers the level; Nicor Gas has no outlook level on this page. Outlook levels, from least to most concern: Stable, Watch, Elevated, High, Severe. Levels describe the public record of capacity and supply risk; confidence is reported separately. They are qualitative assessments, not forecasts of outages.

What's new (as of October 28, 2026)

Two new pipeline expansion filings, from Guardian Pipeline and Natural, cross the metro's counties. Neither says its gas reaches Peoples Gas or North Shore Gas. Details are under 'What is driving new natural gas demand?'

What should Chicago-area facilities check now?

Start with your tariffs and charges, then confirm your utility, your backup plans and the proceedings to watch. - Tariffs and charges, through a utility audit. Confirm each account is on the right rate class and tariff, and that riders, demand charges and capacity-related charges are billed correctly. Over 70% of the clients Discovery Energy has audited were billed incorrectly. An audit verifies tariffs and charges and recovers overcharges before winter costs rise. - Which utility and rate. Confirm whether each site is served by Peoples Gas, North Shore Gas, Nicor Gas or NIPSCO, and which rate class it is on. The filings read do not show which serves which community other than the City of Chicago. Sites served by Nicor Gas are covered by the separate stress record page, not by this outlook level. - Backup plans and fuel. Check that alternate-fuel and curtailment plans are current and feasible, and that fuel inventories and resupply arrangements are in place before December. - Upcoming proceedings. Track Peoples Gas's next annual gas charge reconciliation before the Commission, and any notice about Manlove Field.

Frequently asked questions

Related case studies

Discovery Energy publishes gas capacity case studies for other metros, using the same method and outlook scale.

• Milwaukee natural gas capacity case study (outlook: Watch)
• Detroit natural gas capacity case study (outlook: High)
• Lansing natural gas capacity case study (outlook: Elevated)
• Cincinnati area natural gas capacity case study (outlook: Elevated)
• Pittsburgh natural gas capacity case study (outlook: High)

All gas capacity ratings by U.S. metro

Notes

1. Office of Management and Budget, OMB Bulletin No. 23-01, Revised Delineations of Metropolitan Statistical Areas, Micropolitan Statistical Areas, and Combined Statistical Areas, July 21, 2023. The counties are Cook, DeKalb, DuPage, Grundy, Kane, Kendall, Lake, McHenry and Will counties, Illinois; and Jasper, Lake, Newton and Porter counties, Indiana.
2. Peoples Gas and North Shore Gas, Long-Term Gas Infrastructure Plan overview presentation (September 23, 2024), slide 12 (PDF 12). Utility presentation to stakeholders, not a regulatory filing. ↩
3. The Peoples Gas Light and Coke Company, PGL Ex. 1.0, Direct Testimony of Alese G. Mauermann (April 17, 2025), Illinois Commerce Commission Docket 24-0774, PDF 15 (Reserve Margin). Utility statement. ↩
4. North Shore Gas Company, NSG Ex. 1.0, Direct Testimony of Alese G. Mauermann (April 17, 2025), Illinois Commerce Commission Docket 24-0773, PDF 11 (Reserve Margin). Utility statement. ↩
5. The Peoples Gas Light and Coke Company, PGL Ex. 1.0, Direct Testimony of Alese G. Mauermann (April 17, 2025), Illinois Commerce Commission Docket 24-0774, PDF 12 (Manlove Field); and Peoples Gas and North Shore Gas, Long-Term Gas Infrastructure Plan overview presentation (September 23, 2024), slide 24 (PDF 24), which places Manlove Field in Champaign County, Illinois, outside the metro. Utility statements. ↩
6. Illinois Commerce Commission, Order on Reopening, Dockets 23-0068/23-0069 (April 9, 2026), PDF 2 (Commission analysis and conclusion). Commission order. Two files of the April 9, 2026 order were saved, with different wording in the procedural history; the findings read are the same in both. The Appellate Court vacated the requirement for Nicor Gas in December 2025 and for Peoples Gas and North Shore Gas in March 2026. ↩
7. The Peoples Gas Light and Coke Company, PGL Ex. 1.0, Direct Testimony of Alese G. Mauermann (April 17, 2025), Illinois Commerce Commission Docket 24-0774, PDF 12 (Manlove Field). Utility statement. ↩
8. Peoples Gas and North Shore Gas, Long-Term Gas Infrastructure Plan overview presentation (September 23, 2024), slide 26 (PDF 26, Peak day plan, 2023-2024 winter). Utility presentation to stakeholders, not a regulatory filing. ↩
9. Indiana Utility Regulatory Commission, Orders in Cause No. 46362 (NIPSCO Generation LLC, June 17, 2026, PDF 3 and 11). Commission order summarizing utility testimony; confidential attachments are not public.
10. Illinois Commerce Commission, Order, Docket 24-0774 (April 9, 2026), PDF 2; Direct Testimony of Brett Seagle for Commission Staff (November 5, 2025), PDF 3. A commission order and Staff testimony; neither addresses the reserve margin. The order approved Peoples Gas's 2024 gas charge reconciliation as reasonable and prudent. ↩
11. The Peoples Gas Light and Coke Company, PGL Ex. 1.0, Direct Testimony of Alese G. Mauermann (April 17, 2025), Illinois Commerce Commission Docket 24-0774, PDF 12 (Manlove Field). The testimony gives no month or heating season for the 2022 capacity reduction or for the hydrates in 2021 and 2022. Utility statement. ↩
12. The Peoples Gas Light and Coke Company, PGL Ex. 1.0, Direct Testimony of Alese G. Mauermann (April 17, 2025), Illinois Commerce Commission Docket 24-0774, PDF 12 (Manlove Field). The testimony gives no month or heating season for the 2022 capacity reduction or for the hydrates in 2021 and 2022. Utility statement. ↩
13. Peoples Gas and North Shore Gas, Long-Term Gas Infrastructure Plan overview presentation (September 23, 2024), slides 27 and 28 (PDF 27, Winter Storm Gerri, January 15, 2024; PDF 28, Winter Storm Elliot, December 23, 2022). Utility presentation to stakeholders, not a regulatory filing; it describes no supply shortfall. ↩
14. North Shore Gas Company, NSG Ex. 1.0, Direct Testimony of Alese G. Mauermann (April 17, 2025), Illinois Commerce Commission Docket 24-0773, PDF 11 (Manlove Field). Utility statement. ↩
15. Indiana Utility Regulatory Commission, Order, Cause No. 46362 (NIPSCO Generation LLC, June 17, 2026), PDF 3 (Evidence, Generation Resources). Commission order summarizing utility testimony. ↩
16. Indiana Utility Regulatory Commission, Orders in Cause No. 46362 (June 17, 2026), PDF 4, and Cause No. 46322 (June 17, 2026), PDF 19. The orders state no in-service date for the combined cycle units, no gas volume and no pipeline. Commission orders summarizing utility testimony. ↩
17. Indiana Utility Regulatory Commission, Order, Cause No. 43629 GCA 70, Northern Indiana Public Service Company LLC gas cost adjustment (May 29, 2024), PDF 2 (Source of Natural Gas). A commission order summarizing utility testimony. ↩
18. Nicor Gas, Long-Term Gas Infrastructure Plan overview presentation (September 26, 2024), slide 7 (system overview). Utility presentation. The system map extends to Springfield, Peoria, the Quad Cities, Rockford, Joliet and Bloomington. ↩
19. Indiana Utility Regulatory Commission, Order, Cause No. 43629 GCA 70, Northern Indiana Public Service Company LLC gas cost adjustment (May 29, 2024), PDF 1 (Petitioner's characteristics). The order names no county and gives no design day. ↩
20. Sources for the table: Peoples Gas and North Shore Gas, Long-Term Gas Infrastructure Plan presentation (September 23, 2024), slides 12 and 24; The Peoples Gas Light and Coke Company, Direct Testimony of Alese G. Mauermann (April 17, 2025), Docket 24-0774; Nicor Gas, Long-Term Gas Infrastructure Plan overview presentation (September 26, 2024), slide 7; Indiana Utility Regulatory Commission, Order, Cause No. 43629 GCA 70 (May 29, 2024), PDF 1. ↩
21. Peoples Gas and North Shore Gas, Long-Term Gas Infrastructure Plan overview presentation (September 23, 2024), slide 24 (PDF 24). Utility presentation to stakeholders, not a regulatory filing. ↩
22. The Peoples Gas Light and Coke Company, PGL Ex. 1.0, Direct Testimony of Alese G. Mauermann (April 17, 2025), Illinois Commerce Commission Docket 24-0774, PDF 12 (Manlove Field). The testimony gives no month or heating season for the 2022 capacity reduction or for the hydrates in 2021 and 2022. Utility statement. ↩
23. The Peoples Gas Light and Coke Company, PGL Ex. 1.0, Direct Testimony of Alese G. Mauermann (April 17, 2025), Illinois Commerce Commission Docket 24-0774, PDF 11 (Supply interruptions). Utility statement. ↩
24. The Peoples Gas Light and Coke Company, PGL Ex. 1.0, Direct Testimony of Alese G. Mauermann (April 17, 2025), Illinois Commerce Commission Docket 24-0774, PDF 11 (Pipeline outages); the testimony gives no dates or volumes for the outages. Utility statement. ↩
25. The Peoples Gas Light and Coke Company, PGL Ex. 1.0, Direct Testimony of Alese G. Mauermann (April 17, 2025), Illinois Commerce Commission Docket 24-0774, PDF 11 (Pipeline outages); the testimony gives no dates or volumes for the outages. Utility statement. ↩
26. The Peoples Gas Light and Coke Company, PGL Ex. 1.0, Direct Testimony of Alese G. Mauermann (April 17, 2025), Illinois Commerce Commission Docket 24-0774, PDF 12 (Pipeline outages), in answer to a question about charges associated with outages, cuts, restrictions or other reasons. Utility statement. ↩
27. Supply-event check only partly done: the Nicor Gas, North Shore Gas and NIPSCO records read are presentations and one gas cost order; no federal or state event report, EIA weekly archive keyword search or utility notice archive was searched for them. ↩
28. The Peoples Gas Light and Coke Company, PGL Ex. 1.0, Direct Testimony of Alese G. Mauermann (April 17, 2025), Illinois Commerce Commission Docket 24-0774, PDF 16 (Reserve Margin). Utility statement. ↩
29. The Peoples Gas Light and Coke Company, PGL Ex. 1.0, Direct Testimony of Alese G. Mauermann (April 17, 2025), Illinois Commerce Commission Docket 24-0774, PDF 16 (Reserve Margin). Utility statement. ↩
30. The Peoples Gas Light and Coke Company, PGL Ex. 1.0, Direct Testimony of Alese G. Mauermann (April 17, 2025), Illinois Commerce Commission Docket 24-0774, PDF 15 (Reserve Margin), which says the design day calculation is in its response to Staff data request ENG 1.17. The same testimony also covers citygate purchases (PDF 10), winter-only firm capacity (PDF 10), the pipelines Peoples Gas monitors (PDF 21) and electronic flow measurement locations (PDF 21), which this page does not use. Utility statement. ↩
31. Peoples Gas and North Shore Gas, Long-Term Gas Infrastructure Plan overview presentation (September 23, 2024), slide 23 (PDF 23, Interstate pipeline network). Utility presentation to stakeholders, not a regulatory filing. ↩
32. Peoples Gas and North Shore Gas, Long-Term Gas Infrastructure Plan overview presentation (September 23, 2024), slide 23 (PDF 23). Utility presentation to stakeholders, not a regulatory filing. ↩
33. Peoples Gas and North Shore Gas, Long-Term Gas Infrastructure Plan overview presentation (September 23, 2024), slide 25 (PDF 25). Utility presentation to stakeholders, not a regulatory filing. ↩
34. The Peoples Gas Light and Coke Company, PGL Ex. 1.0, Direct Testimony of Alese G. Mauermann (April 17, 2025), Illinois Commerce Commission Docket 24-0774, PDF 15 (LNG). Utility statement. ↩
35. Peoples Gas and North Shore Gas, Long-Term Gas Infrastructure Plan presentation (December 16, 2024), slide 22 (PDF 22). Utility presentation to stakeholders, not a regulatory filing. ↩
36. Peoples Gas's presentation figures are percentages of its own peak day plan or requirement, and its testimony figure is a percentage of its 2024 design day. The 26%, 27% and 41% Manlove Field figures are not reconciled: the testimony and the September 2024 presentation differ by one point and the December 2024 slide by 15 points, and none states a denominator definition. Stated as Peoples Gas's figures, not as Commission findings. ↩
37. The Peoples Gas Light and Coke Company, PGL Ex. 1.0, Direct Testimony of Alese G. Mauermann (April 17, 2025), Illinois Commerce Commission Docket 24-0774, PDF 13 (Manlove Field). Utility statement. Peoples Gas said the top gas typically cycled annually from Manlove Field is 36,500 Mdth (thousand dekatherms).
38. The Peoples Gas Light and Coke Company, PGL Ex. 1.0, Direct Testimony of Alese G. Mauermann (April 17, 2025), Illinois Commerce Commission Docket 24-0774, PDF 12 (storage use). Utility statement. Peoples Gas said that in 2024 its storage withdrawals were 13.52% below plan, which it attributed to a warm December and balancing.
39. The Peoples Gas Light and Coke Company, PGL Ex. 1.0, Direct Testimony of Alese G. Mauermann (April 17, 2025), Illinois Commerce Commission Docket 24-0774, PDF 13 (North Shore Gas storage service). Utility statement. ↩
40. Peoples Gas and North Shore Gas, Long-Term Gas Infrastructure Plan overview presentation (September 23, 2024), slide 25 (PDF 25). Utility presentation to stakeholders, not a regulatory filing. ↩
41. North Shore Gas Company, NSG Ex. 1.0, Direct Testimony of Alese G. Mauermann (April 17, 2025), Illinois Commerce Commission Docket 24-0773, PDF 11 (Reserve Margin), which points to its response to Staff data request ENG 1.17 for the calculation. Utility statement. ↩
42. North Shore Gas Company, NSG Ex. 1.0, Direct Testimony of Alese G. Mauermann (April 17, 2025), Illinois Commerce Commission Docket 24-0773, PDF 12 (Reserve Margin). Utility statement. ↩
43. North Shore Gas Company, NSG Ex. 1.0, Direct Testimony of Alese G. Mauermann (April 17, 2025), Illinois Commerce Commission Docket 24-0773, PDF 14 (Capacity releases). Utility statement. ↩
44. Nicor Gas, Long-Term Gas Infrastructure Plan overview presentation (September 26, 2024), slides 7, 9 and 10 (system overview, interstate pipelines, underground storage). Utility presentation. The design peak day total is in the slide's MMBtu column; its MWh column reads 1.48 million. ↩
45. Indiana Utility Regulatory Commission, Order, Cause No. 43629 GCA 70, Northern Indiana Public Service Company LLC gas cost adjustment (May 29, 2024), PDF 2 (Source of Natural Gas). A commission order summarizing utility testimony. ↩
46. Indiana Utility Regulatory Commission, Order, Cause No. 43629 GCA 70, Northern Indiana Public Service Company LLC gas cost adjustment (May 29, 2024), PDF 2 (Source of Natural Gas). A commission order summarizing utility testimony. ↩
47. Indiana Utility Regulatory Commission, Order, Cause No. 46362 (NIPSCO Generation LLC, June 17, 2026), PDF 3 and 11 (ordering paragraph 2). Commission order summarizing utility testimony; confidential attachments are not public. ↩
48. Indiana Utility Regulatory Commission, Order, Cause No. 46362 (NIPSCO Generation LLC, June 17, 2026), PDF 3 (Evidence, Generation Resources). Commission order summarizing utility testimony; confidential attachments are not public. ↩
49. Indiana Utility Regulatory Commission, Order, Cause No. 46362 (NIPSCO Generation LLC, June 17, 2026), PDF 4 (Evidence, Generation Resources). Commission order summarizing utility testimony; it states no in-service date for the combined cycle units. ↩
50. Indiana Utility Regulatory Commission, Order, Cause No. 46322 (NIPSCO and GenCo, June 17, 2026), PDF 41 (ordering paragraphs). Commission order. ↩
51. Indiana Utility Regulatory Commission, Order, Cause No. 46322 (NIPSCO and GenCo, June 17, 2026), PDF 19 (Evidence, rebuttal summary). The order names none of the pipelines and gives no gas volume for the new generation. Commission order summarizing utility testimony. ↩
52. Indiana Utility Regulatory Commission, Order, Cause No. 46322 (NIPSCO and GenCo, June 17, 2026), PDF 16 (Evidence, Industrial Group). Commission order summarizing Industrial Group and utility testimony. A witness for the NIPSCO Industrial Group recommended a study of whether and to what extent the planned gas supply arrangements would affect interstate pipeline capacity or NIPSCO's gas transmission system. NIPSCO said it would study the gas usage and identify system impacts. ↩
53. Indiana Utility Regulatory Commission, Order, Cause No. 46322 (NIPSCO and GenCo, June 17, 2026), PDF 16 (Evidence, Industrial Group). Commission order summarizing Industrial Group and utility testimony.
54. Indiana Utility Regulatory Commission, Order, Cause No. 46322 (NIPSCO and GenCo, June 17, 2026), PDF 19 (Evidence, rebuttal summary). Commission order summarizing utility testimony. ↩
55. Indiana Utility Regulatory Commission, Order, Cause No. 45947 (NIPSCO, October 16, 2024), PDF 1 (Verified Petition, summary). Commission order summarizing utility testimony. ↩
56. Indiana Utility Regulatory Commission, Order, Cause No. 45947 (NIPSCO, October 16, 2024), PDF 8 (Evidence, resource need) and PDF 20 (Commission discussion). Commission order summarizing utility testimony. ↩
57. U.S. Energy Information Administration, EIA-860M Preliminary Monthly Electric Generator Inventory, September 2026 (Planned sheet), filtered to the 13 metro counties; it lists 6 planned natural gas-fired generators in those counties. The EIA page saved October 27, 2026 lists September 2026 as its latest inventory and November 24, 2026 as the next release. EIA's status for the R M Schahfer units is that regulatory approvals were received and the units are not under construction. The inventory is not a filing and gives no gas volume or service date confirmed by a filing. EIA's September 2026 inventory is still its latest edition. It lists the four planned Schahfer turbines as approved and not under construction. ↩
58. U.S. Energy Information Administration, EIA-860M Preliminary Monthly Electric Generator Inventory, September 2026 (Planned sheet), filtered to the 13 metro counties. EIA's status for the ITT Cogen units is that they are under construction and more than 50 percent complete. The inventory is not a filing and gives no gas volume or service date confirmed by a filing. The inventory lists the engines as under construction and more than 50 percent complete, and does not name the gas utility that would serve them or call them a data center load. ↩
59. Midcontinent Independent System Operator, generator interconnection queue, public file (4,010 entries), saved October 27, 2026, filtered to the 13 metro counties. The queue lists generation, not data center load. ↩
60. Midcontinent Independent System Operator, generator interconnection queue, public file (4,010 entries), saved October 27, 2026, filtered to the 13 metro counties; fuel type gas or turbine, combined cycle or engine facility type, counted by status (entries J2144 and R5062, Jasper County, Indiana, both withdrawn). The queue lists generation, not data center load. ↩
61. Federal Register, Federal Energy Regulatory Commission notices since January 1, 2025, searched for each of the 13 metro counties with a CP docket number; no notices returned. ↩
62. Risk factor F4 (new load ahead of a fix) is not applied in the proposed rating because the orders give no in-service date for the combined cycle units, no gas volume and no remedy to compare. ↩
63. New-load search partly established (follow-up CHI3, October 27, 2026): the Indiana Utility Regulatory Commission orders in Causes 46362, 46322 and 45947 and the MISO public queue were read and are claimed; the PJM interconnection queue (Queue Scope is a secured application), Illinois EPA air permits (no scriptable search found), the Illinois Commerce Commission e-docket for data center or large gas load filings (disallows automated downloads) and Illinois and Indiana economic development filings were not searched; news and law firm reports are leads only and are not claimed. The orders' confidential material (cost estimates, gas supply arrangements) is not public. ↩
64. Illinois Commerce Commission, Order on Reopening, Dockets 23-0068/23-0069 (April 9, 2026), PDF 1 (procedural history, recounting the November 16, 2023 Final Order). Commission order. ↩
65. North Shore Gas and Peoples Gas, Compliance Filing: Long-Term Gas Infrastructure Plan (Workplan) (July 1, 2024), Dockets 23-0068/23-0069, PDF 7 (Outline of the Plan, Supply Analysis). Utility filing; it gives no figures. ↩
66. The Peoples Gas Light and Coke Company, PGL Ex. 1.0, Direct Testimony of Alese G. Mauermann (April 17, 2025), Illinois Commerce Commission Docket 24-0774, PDF 11 (Significant changes). Utility statement. ↩
67. Nicor Gas, Long-Term Gas Infrastructure Plan: Review of Near Final Plan presentation (May 27, 2025), slide 10 (PDF 10, major projects). Utility presentation. ↩
68. NOAA Climate Prediction Center, Prognostic Discussion for Long-Lead Seasonal Outlooks, issued October 15, 2026 (temperature outlook and ENSO discussion). The discussion names regions, not counties.
69. NOAA Climate Prediction Center, Prognostic Discussion for Long-Lead Seasonal Outlooks, issued October 15, 2026 (temperature outlook and ENSO discussion). The discussion names regions, not counties.
70. U.S. Energy Information Administration, press release, "EIA expects a mixed picture for winter fuel costs this year," October 6, 2026.
71. U.S. Energy Information Administration, Short-Term Energy Outlook, October 2026, PDF 10 (natural gas storage).
72. U.S. Energy Information Administration, press release, "EIA expects a mixed picture for winter fuel costs this year," October 6, 2026, U.S. energy market indicators table.
73. U.S. Energy Information Administration, Weekly Working Gas in Underground Storage, release of October 22, 2026 (Midwest region, six weeks ending September 11 to October 16, 2026). Context only. ↩
74. U.S. Energy Information Administration, Natural Gas Citygate Price in Illinois and in Indiana, monthly tables, July 2026 (latest month saved). Commodity prices, context only, never evidence of a constraint.
75. U.S. Energy Information Administration, Henry Hub Natural Gas Spot Price, daily table, release of October 21, 2026. Context only.
76. Natural Gas Pipeline Company of America, Critical Notices page (Kinder Morgan informational postings), saved October 26 and 27, 2026: first of 3 grid pages, 75 notices posted September 15, 2026 to October 26, 2026, of which 10 are typed capacity constraint and 4 force majeure (for example Alliance Joliet and Northern Border Harper, each primary only, October 12, 2026). The counts cover the newest notices only; none says what it means for deliveries to Peoples Gas. Context only. The page shows the first of three pages of its 90-day list, with 75 notices dated September 15, 2026 to October 26, 2026. Of these, 10 carry the notice type capacity constraint, including primary-only notices for Alliance Joliet and Northern Border Harper on October 12, 2026, and four carry the notice type force majeure (an emergency outage or repair), for its Moraine Lateral and Compressor Station 302. ↩
77. Kinder Morgan Illinois Pipeline, Critical Notices page (Kinder Morgan informational postings), saved October 26, 2026: one gas quality notice posted October 15, 2026; the page holds the whole list for the 90 days before October 26, 2026. Context only. The page holds the whole 90-day list: one gas quality notice dated October 15, 2026.
78. ANR Pipeline Company, Weather Alert Notice 25967909 (December 3, 2025) and four later episode notices, on TC eConnects: Notice 25966610 (Phase 2 cold weather conditions, Extreme Condition for fuel segments ML2, ML3 and ML7, swing percentage lowered from 10% to 5%); episode 1 Notice 25967909 (gas days November 28 to December 4, 2025); episode 2 Notice 25967925 (December 12 to December 16, 2025) with Notice 25970723 lifting it effective gas day December 15 (partial); episode 3 Notice 25972118 (December 30, 2025 to January 3, 2026) with Notice 25972126 lifting it; episode 4 Notice 25973609 (January 17 to January 22, 2026) with Notice 25974423 extending it through February 2, 2026; episode 5 Notice 25984810 (March 16 to March 17, 2026). The 33 distinct gas days are computed from the notices' stated dates for November 1 to March 31. Pipeline notices. Each episode declared an Extreme Condition that lowers the swing percentage to 5% for its fuel segments ML2, ML3 and ML7, for 33 distinct gas days in all. ↩
79. ANR Pipeline Company, Operational Flow Order Notice 25974432 (ML-7 market zone, effective gas day January 22 through January 31, 2026), with ANR's report on Notice 25978016 that the order expired as posted at the end of gas day January 31, 2026 and was implemented due to weather conditions that threatened ANR's ability to maintain line pack. Pipeline notices. The order was effective for gas days January 22 to January 31, 2026. ↩
80. ANR Pipeline Company, Notice 25975909 (underperformance called January 24, 2026 under the ML-7 Operational Flow Order, on groups named WISC GAS GRP 1 and WISC EPC GRP 1 in the notice). Pipeline notice. ANR called an underperformance on January 24 on two groups of Wisconsin delivery locations.
81. ANR Pipeline Company, Notice 25975911 (supplemental Operational Flow Order to all parties north of ANR's Sandwich Compressor Station in the ML-7 market zone, effective gas day Monday, January 26, 2026 through gas day Wednesday, January 28, 2026). Pipeline notice. ANR issued a supplemental order for parties north of its Sandwich Compressor Station for January 26 to January 28, 2026.
82. ANR Pipeline Company, Capacity Constraint Notice 25981411 (unplanned maintenance at Brandon Road Delivery, Michigan Leg South, capacity reduced to zero for February 28 to March 16, 2026, later extended) and Notice 25990124 (capacity reduction lifted April 13, 2026). Pipeline notices. ANR reported unplanned maintenance that reduced its Brandon Road Delivery location on the Michigan Leg South to zero capacity from February 28, 2026 until April 13, 2026.
83. ANR Pipeline Company, Notice 26306042, which places the Michigan Leg South area in Will County, IL. Pipeline notice. ANR's notices place the Michigan Leg South area in Will County, Illinois.
84. Northern Border Pipeline Company, critical notice 25975135 (Capacity Update, January 23, 2026), reducing Des Plaines (DESPLN) to primary only for gas day January 24, 2026. The notice names the Des Plaines delivery point and no utility. Manual browser download, October 27, 2026. The notice gives no end date. ↩
85. ANR Pipeline Company, critical notices on TC eConnects, posted October 1, 2025 to October 27, 2026 (Weather Alert, Operational Flow Order, Maintenance and Capacity Constraint notices, including Notices 25967909, 25970723, 25972126, 25974423, 25984810, 25974432, 25975909, 25975911 and 25981411): 451 notices. Manual browser download, October 27, 2026; the export holds no notice before October 1, 2025, so the public record doesn't show earlier ANR winters. ↩
86. Northern Border Pipeline Company, critical export posted August 18, 2023 to October 13, 2026: 335 notices. Manual browser download, October 27, 2026. Northern Border's critical notices begin in August 2023.
87. Pipeline notice pages, October 27, 2026: ANR and Great Lakes (TC eConnects notices not in the page, later covered for ANR and Northern Border by manual download); Northern Border, Panhandle and Trunkline (unreachable); Guardian (secure connection failed); Vector and Alliance (pages without notices). No winter count of pipeline critical notices could be made for winter 2023-24, 2024-25 and 2025-26 from the pages read. ↩
88. Illinois Commerce Commission, Order on Reopening, Dockets 23-0068/23-0069 (January 21, 2026), PDF 2 (procedural history). Commission order. ↩
89. Illinois Commerce Commission, Order on Reopening, Dockets 23-0068/23-0069 (April 9, 2026), PDF 2 (procedural history), quoting the Illinois Appellate Court, Third District, decision of December 1, 2025 on Nicor Gas's appeal. Commission order.
90. Illinois Capital Development Board, Illinois Energy Conservation Code page (20 ILCS 3125/15), saved October 27, 2026. The page does not mention natural gas. ↩
91. Illinois Capital Development Board, Illinois Stretch Energy Code page (20 ILCS 3125/55), saved October 27, 2026. The page does not say which municipalities in the metro have adopted it. ↩
92. Peoples Gas and North Shore Gas stated margins: Direct Testimony of Alese G. Mauermann (April 17, 2025), Illinois Commerce Commission Dockets 24-0774 (PDF 15) and 24-0773 (PDF 11); plan requirement vacated: Illinois Commerce Commission, Order on Reopening, Dockets 23-0068/23-0069 (April 9, 2026), PDF 2. ↩
93. The Peoples Gas Light and Coke Company, PGL Ex. 1.0, Direct Testimony of Alese G. Mauermann (April 17, 2025), Illinois Commerce Commission Docket 24-0774, PDF 11 and 12 (Manlove Field, Supply interruptions, Pipeline outages). Utility statement. ↩
94. Pipeline notices (follow-up CHI3, October 27, 2026, updated by RUN-B the same day): Natural's page was read for its first of three pages and Kinder Morgan Illinois Pipeline's for its whole list; the pages list a 90-day window, but the saved Natural page holds only 75 of its notices, so its counts are for the newest notices only. ANR and Northern Border notice exports were added from manual browser downloads (the ANR and Northern Border notices described above); Great Lakes, Panhandle and Trunkline (unreachable), Guardian (secure connection failed), and Vector and Alliance (pages without notices) were not read.
95. The ANR notices do not expand the fuel segment names ML2, ML3 and ML7 or the location group names, and do not name a utility; the mapping of these areas to the metro is an inference from the area names.
96. Policy context (follow-up CHI3): two Illinois Capital Development Board code pages and the Commission's own orders on the vacated plan requirement were read; Illinois General Assembly pages could not be fetched (secure connection failed), and the Illinois data center incentive page path searched returned not found, so no Illinois statute on data centers or gas planning was read; Indiana statutes were not searched (the brief names Illinois and Michigan). The section is context only.
97. Not established, and left out of the page: who pays (cost allocation among customer classes, which the Order on 2024 gas charge reconciliation does not address); tariff interruption priorities and penalties for Peoples Gas, North Shore Gas, Nicor Gas and NIPSCO; delivery-point utilization from pipeline postings (next capture about March 2027); the design day calculations in Peoples Gas's and North Shore Gas's responses to Staff data request ENG 1.17; Nicor Gas's and NIPSCO's reserve margins (and any rating of Nicor Gas's suburbs); the Nicor Gas, North Shore Gas and NIPSCO territories by county; Kenosha County, Wisconsin.
98. Indiana Utility Regulatory Commission, IURC Order in Cause No. 46322, dated 2026-06-17, saved 2026-10-28; PDF page 39. ↩
99. U.S. Energy Information Administration, EIA-860M September 2026, Planned generators, dated 2026-09, saved 2026-10-28; Planned sheet, R M Schahfer rows 19A, 19B, 19C and 20, Jasper County, IN.
100. U.S. Energy Information Administration, EIA-860M September 2026, Planned generators, dated 2026-09, saved 2026-10-28; Planned sheet, ITT Cogen Facility rows GEN3 and GEN4, Cook County, IL.
101. Federal Energy Regulatory Commission (Federal Register), Notice of Effectiveness of Exempt Wholesale Generator and Foreign Utility Company Status, EG26-253-000 et al., dated 2026-09-09, saved 2026-10-28; Notice of Effectiveness of EWG Status, list of entities. ↩
102. Searches of October 28, 2026: EIA-860M September 2026 (planned and canceled sheets) filtered to the nine Illinois and four Indiana metro counties; Federal Register FERC notices since July 30, 2026 for ANR, Midwestern, Vector, Guardian, Natural Gas Pipeline Company of America, Northern Border, Alliance, Northern Natural, NIPSCO, Nicor, Peoples Gas and North Shore Gas; the Indiana Utility Regulatory Commission order in Cause No. 46322. Not reviewed: Illinois Commerce Commission e-docket, Indiana commission online services, FERC eLibrary, PJM queue, Illinois EPA permit notices, pipeline informational postings. ↩
103. NOAA Regional Climate Centers, Applied Climate Information System (ACIS) StnData web service, monthly heating degree days (base 65F) and 1991-2020 normals, November to March of winters 2023-24 to 2025-26, retrieved October 26 to 28, 2026: CHICAGO OHARE INTL AP. Sums computed. ↩
104. NOAA Climate Prediction Center, seasonal temperature outlook issued October 15, 2026, shapefiles lead1 (November to January) and lead2 (December to February) from ftp.cpc.ncep.noaa.gov/GIS/us_tempprcpfcst/seastemp_202610.zip, read at each metro's coordinates. The map gives the favored category and the lower edge of its probability band; NOAA's own explanation (Link) keeps near-normal at 33.3% and gives the opposite category the rest, so the above-normal figure is a floor and the below-normal figure a ceiling. The November 2026 to January 2027 outlook gives the Chicago area at least a 40% chance of above-normal temperatures, about 33% near-normal and no more than 27% below-normal; the December 2026 to February 2027 outlook gives at least a 50% chance of above-normal temperatures, about 33% near-normal and no more than 17% below-normal. A lean toward warmer weather does not rule out cold days. ↩
105. Federal Energy Regulatory Commission (Federal Register), Guardian Pipeline, LLC; Notice of Schedule for the Preparation of an Environmental Assessment for the Guardian 3 Expansion Project, CP26-548-000, dated 2026-09-29, saved 2026-10-28; Notice, first paragraph. Federal Energy Regulatory Commission (Federal Register), Guardian Pipeline, LLC; Notice of Scoping Period Requesting Comments on Environmental Issues for the Proposed Guardian 3 Expansion Project, CP26-548-000, dated 2026-08-03, saved 2026-10-28; Notice, first paragraph. FERC's September 29, 2026 notice says Guardian Pipeline filed on July 1, 2026, and that FERC staff plan their environmental assessment for March 5, 2027. FERC's August 3, 2026 notice places the Illinois facilities in Kendall, DeKalb, McHenry and Will counties. ↩
106. DT Midstream (Guardian Pipeline), Guardian Pipeline G3 Expansion Project fact sheet, CP26-548-000, dated 2026-08-12, saved 2026-10-28; PDF page 1. ↩
107. Federal Energy Regulatory Commission (Federal Register), Natural Gas Pipeline Company of America LLC; Horizon Pipeline Company, L.L.C.; Notice of Application and Establishing Intervention Deadline, CP26-564-000, dated 2026-08-24, saved 2026-10-28; Notice of application, first paragraph. Federal Energy Regulatory Commission (Federal Register), Natural Gas Pipeline Company of America LLC; Horizon Pipeline Company, L.L.C.; Notice of Application and Establishing Intervention Deadline, CP26-564-000, dated 2026-08-24, saved 2026-10-28; Notice of application, project description. ↩
108. Method for the metro definition: the metro is the Chicago-Naperville-Elgin, IL-IN metropolitan statistical area as delineated by the Office of Management and Budget (OMB) on July 21, 2023 (note 1). The utility records on this page were sorted by whether their service area falls inside the counties of that list; Kenosha County, Wisconsin, is not on it. Sources for that sorting are in note 20. ↩
109. Method for the pipeline table totals: each total is the sum of the pipeline figures above it for that utility, added. The figures are for each utility's whole system. ↩
110. Method for the heating degree day table: totals and percentages of the 1991-2020 normal are computed from NOAA Applied Climate Information System (ACIS) data (note 103). ↩
111. National conditions and commodity prices. NOAA's Climate Prediction Center said on October 15, 2026 that its November 2026 to January 2027 outlook gives the highest odds of warmer than normal conditions to Southeast Alaska, the upper Mississippi Valley and the Great Lakes (note 68), and that the probability of at least a strong El Nino event continuing through January to March 2027 is 80% (note 69). EIA said on October 6, 2026 that it expects U.S. natural gas inventories to enter the winter 2% above the previous five-year average (note 70). EIA's October 2026 Short-Term Energy Outlook says prolonged cold could increase withdrawals beyond its forecast (note 71), and lists U.S. LNG gross exports of 15, 18 and 19 billion cubic feet per day for 2025, 2026 and 2027 (note 72). EIA's citygate price tables (the price where gas enters a local utility's system) list 3.75 dollars per thousand cubic feet for Illinois and 4.01 for Indiana for July 2026, the latest month saved (note 74). Its Henry Hub spot table, released October 21, 2026, lists 3.28 and 3.10 dollars per million Btu for the first days reported of the week of October 19, 2026 (note 75). These are commodity prices and are not evidence of a constraint. ↩

Market and weather sources

Public web sources saved and hashed on October 25 and 26, 2026. They are context, separate from the regulatory record cited in the Notes. The Climate Prediction Center issues its seasonal outlook once each month near mid-month; this section is refreshed on the publication date.

1. A1. U.S. Energy Information Administration, press release, "EIA expects a mixed picture for winter fuel costs this year," October 6, 2026. Link
2. A2. U.S. Energy Information Administration, Short-Term Energy Outlook, October 2026 (natural gas storage). Link
3. B1. NOAA Climate Prediction Center, Prognostic Discussion for Long-Lead Seasonal Outlooks, issued October 15, 2026. Link
4. C1. U.S. Energy Information Administration, Weekly Working Gas in Underground Storage, release of October 22, 2026. Link
5. C2. U.S. Energy Information Administration, Natural Gas Citygate Price in Illinois, monthly. Link
6. C3. U.S. Energy Information Administration, Henry Hub Natural Gas Spot Price, daily, release of October 21, 2026. Link
7. C4. U.S. Energy Information Administration, Natural Gas Citygate Price in Indiana, monthly. Link
8. D1. Natural, Critical Notices (Kinder Morgan informational postings), saved October 26 and 27, 2026 (first of three pages). Link
9. D2. Kinder Morgan Illinois Pipeline, Critical Notices (Kinder Morgan informational postings), saved October 26, 2026. Link

Policy sources

Official sources saved and hashed on October 26 and 27, 2026. They are context, separate from the regulatory record cited in the Notes.

1. P1. Illinois Commerce Commission, Order on Reopening, Dockets 23-0068/23-0069 (cons.), April 9, 2026. Link
2. P2. Illinois Commerce Commission, Order on Reopening, Dockets 23-0068/23-0069 (cons.), January 21, 2026. Link
3. P3. Illinois Capital Development Board, Illinois Energy Conservation Code (20 ILCS 3125/15), saved October 27, 2026. Link
4. P4. Illinois Capital Development Board, Illinois Stretch Energy Code (20 ILCS 3125/55), saved October 27, 2026. Link

Sources

1. Illinois Commerce Commission, Docket 24-0774, The Peoples Gas Light and Coke Company, reconciliation of revenues collected under gas adjustment charges with actual costs prudently incurred (2024). Link
2. Illinois Commerce Commission, Docket 24-0773, North Shore Gas Company, reconciliation of revenues collected under gas adjustment charges with actual costs prudently incurred (2024). Link
3. Illinois Commerce Commission, Dockets 23-0068/23-0069 (cons.), North Shore Gas Company and The Peoples Gas Light and Coke Company general rate case, long-term gas infrastructure plan workplan and orders on reopening. Link
4. Peoples Gas and North Shore Gas, Long-Term Gas Infrastructure Plan presentations, September 23 and December 16, 2024. Link
5. Nicor Gas, Long-Term Gas Infrastructure Plan presentations, September 26, 2024 and May 27, 2025. Link
6. Indiana Utility Regulatory Commission, Cause No. 43629 GCA 70, Order, May 29, 2024. Link
7. Office of Management and Budget, OMB Bulletin No. 23-01, Revised Delineations of Metropolitan Statistical Areas, Micropolitan Statistical Areas, and Combined Statistical Areas, July 21, 2023.
8. U.S. Energy Information Administration, EIA-860M Preliminary Monthly Electric Generator Inventory, September 2026. Link
9. Federal Register, Federal Energy Regulatory Commission notices, searched by county. Link
10. Indiana Utility Regulatory Commission, Cause No. 46362 order (June 17, 2026). Link
11. Indiana Utility Regulatory Commission, Cause No. 46322 order (June 17, 2026). Link
12. Indiana Utility Regulatory Commission, Cause No. 45947 order (October 16, 2024). Link
13. Midcontinent Independent System Operator, generator interconnection queue. Link
14. ANR Pipeline Company, critical and non-critical notices, TC eConnects, saved October 27, 2026 (manual browser download).
15. Northern Border Pipeline Company, critical and non-critical notices, TC eConnects, saved October 27, 2026 (manual browser download).