13.

Variable Interest Entities

Following is a description of our financial interests in both unconsolidated and consolidated variable interest entities that we consider significant:

Low-Income Housing Properties and Refined Coal Facility Investments

We have investments in entities established to manage low-income housing properties and a refined coal facility. We support the operations of these entities in exchange for a pro-rata share of the tax credits they generate. We do not consolidate these entities as we have determined we are not the primary beneficiary of these entities as we do not have the power to individually direct the activities of these entities. Accordingly, we account for these investments under the equity method of accounting. Our aggregate investment balance in these two entities was $72 million and $84 million, as of June 30, 2017 and December 31, 2016, respectively. The debt balance related to our investment in low-income housing properties was $45 million and $57 million as of June 30, 2017 and December 31, 2016, respectively. Additional information related to these investments is discussed in Note 4.

Trust Funds for Final Capping, Closure, Post-Closure or Environmental Remediation Obligations

We have significant financial interests in trust funds that were created to settle certain of our final capping, closure, post-closure or environmental remediation obligations. These trust funds are established such that we are either the sole beneficiary of these restricted balances or we share benefit with the host community in which we operate. We have determined that these trust funds are variable interest entities; however, we are not the primary beneficiary of certain of these entities, as described further below. As the party with primary responsibility to fund the related final capping, closure, post-closure or environmental remediation activities for these trust funds, we are exposed to risk of loss if there are declines in the fair value of the assets of the trust. We currently expect the trust funds to continue to meet the statutory requirements for which they were established.

Unconsolidated Variable Interest Entities — Trust funds that are established for both the benefit of the Company and the host community in which we operate are not consolidated because we are not the primary beneficiary of these entities as we either do not have the (i) power to direct the significant activities of the trusts or (ii) power over the trusts’ significant activities is shared. Our interests in these trusts are accounted for as investments in unconsolidated entities and receivables. These amounts are recorded in other receivables, investments in unconsolidated entities and long-term other assets in our Condensed Consolidated Balance Sheets, as appropriate. We also reflect our share of the unrealized gains and losses on available-for-sale securities held by these trusts as a component of our accumulated other comprehensive income or loss. Our investments and receivables related to these trusts had an aggregate carrying value of $98 million and $93 million as of June 30, 2017 and December 31, 2016, respectively.

Consolidated Variable Interest Entities — Trust funds of which we are the sole beneficiary are consolidated because we are the primary beneficiary. We account for these trust funds as long-term other assets in our Condensed Consolidated Balance Sheets. Unrealized gains and losses on available-for-sale securities held by these trusts are recorded as a component of accumulated other comprehensive income or loss. These trusts had a fair value of $99 million and $95 million as of June 30, 2017 and December 31, 2016, respectively.