13.

Variable Interest Entities

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

Unconsolidated Variable Interest Entities

Low-Income Housing Properties and Refined Coal Facility Investments — We have significant financial interests in entities established to invest in and 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. As of March 31, 2017 and December 31, 2016, our aggregate investment balance in these two entities was $81 million and $84 million, respectively. The debt balance related to our investment in low-income housing properties was $51 million and $57 million as of March 31, 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. Certain of the funds have been established for the benefit of both the Company and the host community in which we operate. We have determined that these trust funds are variable interest entities; however, we do not consolidate these trust funds as we are not the primary beneficiary of these entities because either (i) we do not have the 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. Our investments and receivables related to these trusts had an aggregate carrying value of $95 million and $93 million as of March 31, 2017 and December 31, 2016, respectively.

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.

Consolidated Variable Interest Entities

Trust Funds for Final Capping, Closure, Post-Closure or Environmental Remediation Obligations — We also have significant financial interests in trust funds, for which we are the sole beneficiary, that were created to settle certain of our final capping, closure, post-closure or environmental remediation obligations. We have determined that these trust funds are variable interest entities, and we consolidate these trust funds because we are the primary beneficiary. We account for these trust funds as long-term other assets in our Condensed Consolidated Balance Sheets. We reflect our interests in the unrealized gains and losses on available-for-sale securities held by these trusts as a component of accumulated other comprehensive loss. These trusts had a fair value of $97 million and $95 million as of March 31, 2017 and December 31, 2016, respectively.

We also have primary responsibility to fund the related final capping, closure, post-closure or environmental remediation activities for these trust funds, and 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.