Commitments and Contingencies (a) Natural Gas Supply Commitments (CenterPoint Energy and CERC) Natural gas supply commitments include natural gas contracts related to CenterPoint Energys and CERCs Natural Gas Distribution and Energy Services business segments, which have various quantity requirements and durations, that are not classified as non-trading derivative assets and liabilities in CenterPoint Energys and CERCs Condensed Consolidated Balance Sheets as of September 30, 2018 and December 31, 2017 as these contracts meet an exception as normal purchases contracts or do not meet the definition of a derivative. Natural gas supply commitments also include natural gas transportation contracts that do not meet the definition of a derivative. As of September 30, 2018 , minimum payment obligations for natural gas supply commitments are approximately: (in millions) Remaining three months of 2018 $ 88 2019 325 2020 303 2021 219 2022 183 2023 and beyond 1,644 (b) Legal, Environmental and Other Matters Legal Matters Gas Market Manipulation Cases (CenterPoint Energy and CERC) . CenterPoint Energy, its predecessor, Reliant Energy, and certain of their former subsidiaries were named as defendants in a large number of lawsuits filed against numerous gas market participants in a number of federal and western state courts in connection with the operation of the natural gas markets in 2000-2002. CenterPoint Energy and its affiliates were released or dismissed from all such cases, except for one case pending in federal court in Nevada in which CES, a subsidiary of CERC Corp., is a defendant. Plaintiffs in that case allege a conspiracy to inflate Wisconsin natural gas prices in 2000-2002. In May 2016, the district court granted CESs motion for summary judgment, dismissing CES from the case. In August 2018, the Ninth Circuit Court of Appeals reversed that ruling, and CES requested further appellate review of that decision. Under a master separation agreement between CenterPoint Energy and a former subsidiary, RRI, CenterPoint Energy and its subsidiaries are entitled to be indemnified by RRI and its successors for any losses, including certain attorneys fees and other costs, arising out of these lawsuits. Through a series of transactions, RRI became known as GenOn and a wholly-owned subsidiary of NRG. None of those transactions alters GenOns contractual obligations to indemnify CenterPoint Energy and its subsidiaries for certain liabilities, including their indemnification obligations regarding the gas market manipulation litigation. In June 2017, however, GenOn and various affiliates filed for protection under Chapter 11 of the U.S. Bankruptcy Code and are expected to emerge from Chapter 11 in 2018. CenterPoint Energy, CERC, and CES submitted proofs of claim in the bankruptcy proceedings to protect their indemnity rights. In October 2018, CES, GenOn, and the plaintiffs reached an agreement to settle all claims against CES and CESs indemnity claims against GenOn, subject to approvals by the bankruptcy court and the federal district court. If the settlement agreement is not approved and if GenOns bankruptcy proceedings result in it not being required to fulfill its indemnity obligations, CES could incur liability and be responsible for satisfying it. CenterPoint Energy does not expect the ultimate outcome of this matter to have a material adverse effect on its financial condition, results of operations or cash flows. Minnehaha Academy (CenterPoint Energy and CERC). On August 2, 2017, a natural gas explosion occurred at the Minnehaha Academy in Minneapolis, Minnesota, resulting in the deaths of two school employees, serious injuries to others and significant property damage to the school. CenterPoint Energy, certain of its subsidiaries, including CERC, and the contractor company working in the school have been named in litigation arising out of this incident. CenterPoint Energy has reached confidential settlement agreements with some claimants. Additionally, CenterPoint Energy is cooperating with the ongoing investigation conducted by the National Transportation Safety Board. Further, CenterPoint Energy is contesting approximately $200,000 in fines imposed by the Minnesota Office of Pipeline Safety. In early 2018, the Minnesota Occupational Safety and Health Administration concluded its investigation without any adverse findings against CenterPoint Energy. CenterPoint Energys general and excess liability insurance policies provide coverage for third party bodily injury and property damage claims. Environmental Matters MGP Sites (CenterPoint Energy and CERC). CERC and its predecessors operated MGPs in the past. With respect to certain Minnesota MGP sites, CERC has completed state-ordered remediation and continues state-ordered monitoring and water treatment. As of September 30, 2018 , CERC had a recorded liability of $7 million for continued monitoring and any future remediation required by regulators in Minnesota. The estimated range of possible remediation costs for the sites for which CERC believes it may have responsibility was $4 million to $30 million based on remediation continuing for 30 to 50 years. The cost estimates are based on studies of a site or industry average costs for remediation of sites of similar size. The actual remediation costs will depend on the number of sites to be remediated, the participation of other PRPs, if any, and the remediation methods used. In addition to the Minnesota sites, the EPA and other regulators have investigated MGP sites that were owned or operated by CERC or may have been owned by one of its former affiliates. CenterPoint Energy and CERC do not expect the ultimate outcome of these matters to have a material adverse effect on the financial condition, results of operations or cash flows of either CenterPoint Energy or CERC. Asbestos. Some facilities owned by the Registrants or their predecessors in interest contain or have contained asbestos insulation and other asbestos-containing materials. The Registrants are from time to time named, along with numerous others, as defendants in lawsuits filed by a number of individuals who claim injury due to exposure to asbestos, and the Registrants anticipate that additional claims may be asserted in the future. Although their ultimate outcome cannot be predicted at this time, the Registrants do not expect these matters, either individually or in the aggregate, to have a material adverse effect on their financial condition, results of operations or cash flows. Other Environmental. From time to time, the Registrants identify the presence of environmental contaminants during operations or on property where predecessor companies have conducted operations. Other such sites involving contaminants may be identified in the future. The Registrants have and expect to continue to remediate any identified sites consistent with state and federal legal obligations. From time to time, the Registrants have received notices, and may receive notices in the future, from regulatory authorities or others regarding status as a PRP in connection with sites found to require remediation due to the presence of environmental contaminants. In addition, the Registrants have been, or may be, named from time to time as defendants in litigation related to such sites. Although the ultimate outcome of such matters cannot be predicted at this time, the Registrants do not expect these matters, either individually or in the aggregate, to have a material adverse effect on their financial condition, results of operations or cash flows. Other Proceedings The Registrants are involved in other legal, environmental, tax and regulatory proceedings before various courts, regulatory commissions and governmental agencies regarding matters arising in the ordinary course of business. From time to time, the Registrants are also defendants in legal proceedings with respect to claims brought by various plaintiffs against broad groups of participants in the energy industry. Some of these proceedings involve substantial amounts. The Registrants regularly analyze current information and, as necessary, provide accruals for probable and reasonably estimable liabilities on the eventual disposition of these matters. The Registrants do not expect the disposition of these matters to have a material adverse effect on the Registrants financial condition, results of operations or cash flows.