NIPSCO Industrial Group v. Northern Indiana Public Service Company, and Office of the Utility Consumer Counselor, 125 N.E.3d 617

Background

NIPSCO sought and obtained Commission approval of a base rate case settlement (including "Joint Exhibit D" allocation factors) and a multi-year TDSIC plan settlement; the Industrial Group was a signatory to both settlements and supported the allocation factors at those times.
The TDSIC statutory framework allows a utility to pre-approve multi-year transmission/distribution/storage projects (Section 10) and to file periodic Section 9 petitions to recover 80% of approved capital expenditures, requiring use of customer-class revenue allocation factors "based on firm load" from the most recent base rate order.
NIPSCO filed TDSIC-1 using the Joint Exhibit D allocation factors (no objection). NIPSCO filed TDSIC-2 using the same allocation factors; the Industrial Group objected asserting the factors were based on total load (firm + interruptible) not firm load as required by statute.
The Commission approved TDSIC-2, citing the parties’ prior settlements and orders adopting Joint Exhibit D; it concluded the settlements left no question about which factors applied.
The Court of Appeals reversed, holding the allocation factors were computed on total load and the Commission exceeded its statutory authority; the Indiana Supreme Court granted transfer, vacating the panel opinion.
The Indiana Supreme Court affirmed the Commission, holding the Industrial Group is estopped from belatedly challenging settlement terms it previously advocated and that the Commission’s order contained sufficient findings.

Issues

Issue	Industrial Group's Argument	NIPSCO/OUCC's Argument	Held
Whether allocation factors used in TDSIC-2 complied with Section 9’s requirement they be based on "firm load"	Allocation factors were computed on total load and thus violated the statute	Allocation factors in Joint Exhibit D were approved in the base-rate settlement/order and adopted by the TDSIC-plan settlement; Commission approval of TDSIC-2 was proper	Court treated the challenge as an attack on prior settlements and, applying estoppel, rejected the late statutory challenge
Whether a party to and proponent of settlements can later challenge those settlement terms in a subsequent proceeding	Industrial Group may still raise statutory compliance claims regardless of prior support	Industrial Group is estopped from reversing its earlier position after inducing reliance by others	Held: Industrial Group estopped from challenging the allocation factors now
Whether the Commission’s TDSIC-2 order contained specific findings sufficient to support its decision	Order lacked specific findings tying the allocation factors to statutory "firm load" requirement	Order contained findings describing prior settlements, approvals, and the parties’ agreements; within Commission expertise	Held: Commission’s findings were sufficient and its conclusion reasonable
Proper standard of review for mixed questions of law and fact and deference to agency expertise	Industrial Group implies court should independently resolve statutory interpretation	NIPSCO/OUCC emphasize deference to Commission on mixed fact-law matters and settlements	Held: Court gives deference to Commission on matters within its expertise and reviews reasonableness for mixed questions

Key Cases Cited

NIPSCO Indus. Grp. v. N. Ind. Pub. Serv. Co., 100 N.E.3d 234 (Ind. 2018) (describes TDSIC statutory procedure and prior related ruling)
U.S. Gypsum, Inc. v. Ind. Gas Co., 735 N.E.2d 790 (Ind. 2000) (explains scope of base-rate case review)
U.S. Steel Corp. v. N. Ind. Pub. Serv. Co., 907 N.E.2d 1012 (Ind. 2009) (establishes deference and requirement for specific findings from the Commission)
Ind. Gas Co. v. Ind. Fin. Auth., 999 N.E.2d 63 (Ind. 2013) (discusses review of mixed questions of law and fact and findings sufficiency)
Davis v. Wakelee, 156 U.S. 680 (U.S. 1895) (articulates equitable estoppel principle preventing a party from switching positions to the prejudice of others)
Speckman v. City of Indianapolis, 540 N.E.2d 1189 (Ind. 1989) (applies estoppel principles to bar inconsistent litigation positions)