Commitments and Contingencies (Tables)

9 Months Ended

Sep. 30, 2019

Commitments and Contingencies Disclosure [Abstract]

Long-term Purchase Commitment [Table Text Block]

As of September 30, 2019, minimum purchase obligations are approximately:

	CenterPoint Energy		CERC
	(in millions)
Remaining three months of 2019	$	217	$	160
2020	745		528
2021	614		429
2022	412		235
2023	330		177
2024	265		169
2025 and beyond	1,846		1,483

Schedule of Environmental Loss Contingencies by Site [Table Text Block]

MGP Sites. CenterPoint Energy, CERC and their predecessors operated MGPs in the past. In addition, certain of CenterPoint Energy’s subsidiaries acquired through the Merger operated MGPs in the past. The costs CenterPoint Energy or CERC, as applicable, expect to incur to fulfill their respective obligations are estimated by management using assumptions based on actual costs incurred, the timing of expected future payments and inflation factors, among others. While CenterPoint Energy and CERC have recorded all costs which they presently are obligated to incur in connection with activities at these sites, it is possible that future events may require remedial activities which are not presently foreseen, and those costs may not be subject to PRP or insurance recovery.

(i) Minnesota MGPs (CenterPoint Energy and CERC). With respect to certain Minnesota MGP sites, CenterPoint Energy and CERC have completed state-ordered remediation and continue state-ordered monitoring and water treatment. CenterPoint Energy and CERC recorded a liability as reflected in the table below for continued monitoring and any future remediation required by regulators in Minnesota.

(ii) Indiana MGPs (CenterPoint Energy). In the Indiana Gas service territory, the existence, location and certain general characteristics of 26 gas manufacturing and storage sites have been identified for which CenterPoint Energy may have some remedial responsibility. A remedial investigation/feasibility study was completed at one of the sites under an agreed upon order between Indiana Gas and the IDEM, and a Record of Decision was issued by the IDEM in January 2000. The remaining sites have been submitted to the IDEM’s VRP. CenterPoint Energy has also identified its involvement in five manufactured gas plant sites in SIGECO’s service territory, all of which are currently enrolled in the IDEM’s VRP. CenterPoint Energy is currently conducting some level of remedial activities, including groundwater monitoring at certain sites.

(iii) Other MGPs (CenterPoint Energy and CERC). In addition to the Minnesota and Indiana sites, the EPA and other regulators have investigated MGP sites that were owned or operated by CenterPoint Energy or CERC or may have been owned by one of their former affiliates.

Total costs that may be incurred in connection with addressing these sites cannot be determined at this time. The estimated accrued costs are limited to CenterPoint Energy’s and CERC’s share of the remediation efforts and are therefore net of exposures of other PRPs. The estimated range of possible remediation costs for the sites for which CenterPoint Energy and CERC believe they may have responsibility was based on remediation continuing for the minimum time frame given in the table below.

	September 30, 2019
	CenterPoint Energy		CERC
	(in millions, except years)
Amount accrued for remediation	$	9	$	7
Minimum estimated remediation costs	7		4
Maximum estimated remediation costs	51		32
Minimum years of remediation	5		30
Maximum years of remediation	50		50