Commitments and Contingencies

Commitments. We have a variety of financial commitments, including purchase agreements, forward foreign exchange and forward sales contracts, indebtedness and letters of credit (see Note 3 and Note 10).

Rental expenses were $8.2 million, $7.4 million and $7.5 million for 2015, 2014 and 2013, respectively. There are renewal options in various operating leases subject to certain terms and conditions. Minimum rental commitments under operating leases at December 31, 2015 were as follows (in millions of dollars):



	Year Ended December 31,
	2016		2017		2018		2019		2020		2021 and Thereafter
Minimum rental commitments	$	6.2	$	5.1	$	4.1	$	3.9	$	2.2	$	25.8

Our purchase obligations at December 31, 2015 consisted of: (i) various contracts with suppliers of aluminum that require us to purchase minimum quantities of aluminum in 2016 at a price to be determined at the time of purchase based primarily on the underlying metal price at that time; (ii) energy contracts requiring us to purchase minimum quantities of energy in future years at a fixed price; and (iii) cash commitments for future equipment purchases. Amounts to be purchased in 2016 under the variable priced metal contracts totaled $140.6 million and are included in the table below based on minimum quantities at the metal price as of December 31, 2015. We believe the minimum quantities are lower than our current requirements for aluminum. Actual quantities and actual metal prices at the time of purchase could be different. All remaining amounts in the table below relate to the fixed price electricity contracts discussed above. The total amounts due under purchase obligations as of December 31, 2015 were as follows (in millions of dollars):



	Year Ended December 31,
	2016		2017		2018		2019		2020		2021 and Thereafter
Raw materials	$	179.3	$	—	$	—	$	—	$	—	$	—
Energy	10.3		9.5		5.6		0.6		0.6		1.5
Capital equipment	5.2		0.1		—		—		—		—
Total purchase obligations	$	194.8	$	9.6	$	5.6	$	0.6	$	0.6	$	1.5

Environmental Contingencies. We are subject to a number of environmental laws and regulations, to potential fines or penalties assessed for alleged breaches of such laws and regulations and to potential claims based upon such laws and regulations.

We have established procedures for regularly evaluating environmental loss contingencies. Our environmental accruals represent our undiscounted estimate of costs reasonably expected to be incurred based on presently enacted laws and regulations, existing requirements, currently available facts, existing technology and our assessment of the likely remediation actions to be taken.

The following table presents the changes in such accruals, which are primarily included in Long-term liabilities (in millions of dollars):



	Year Ended December 31,
	2015			2014			2013
Beginning balance	$	19.3		$	22.8		$	21.7
Additional accruals	1.3			0.8			4.5
Less expenditures	(2.0		)	(4.3		)	(3.4		)
Ending balance	$	18.6		$	19.3		$	22.8

In 2012, we submitted a final feasibility study to the Washington State Department of Ecology ("Washington State Ecology") that included recommendations for remediation alternatives primarily to address the historical use of oils containing polychlorinated biphenyls ("PCBs") at our Trentwood facility. We also signed an amended work order in 2012 with Washington State Ecology allowing certain remediation activities to begin the initiation of a treatability study in regards to proposed PCB remediation methods. We began implementation of certain approved sections of the work plan in 2013 and throughout 2014, completing a number of these sections in 2014 and receiving approval from Washington State Ecology. Also in cooperation with Washington State Ecology, we began construction of a pilot test facility to implement the treatability study and evaluate the feasibility of removing PCBs from ground water under the Trentwood facility. As pilot testing has only begun and the success of the new methodology cannot be reasonably determined at this time, it is possible we may need to make upward adjustments to our related accruals as facts and cost estimates regarding the groundwater treatment method become available.

During 2013, at the request of the Ohio Environmental Protection Agency ("OEPA"), we initiated an investigational study of the Newark facility related to historical on-site waste disposal. During 2014 and 2015, we completed a number of preliminary steps in the preparation of completing the final risk assessment and feasibility study, both of which are subject to review and approval by the OEPA. As work continues and progresses to a final risk assessment and feasibility study, we will establish and update estimates for probable and estimable remediation, if any. The actual and final cost for remediation will not be fully determinable until a final feasibility study is submitted and accepted by the OEPA and work plans are prepared, which is expected to occur in the next 12 to 18 months.

At December 31, 2015, our environmental accrual of $18.6 million represented our estimate of the incremental remediation cost based on: (i) proposed alternatives in the final feasibility study related to the Trentwood facility; (ii) currently available facts with respect to our Newark facility; and (iii) facts related to certain other locations owned or formally owned by us. In accordance with approved and proposed remediation action plans, we expect that the implementation and ongoing monitoring could occur over a period of 30 or more years.

As additional facts are developed, feasibility studies are completed, draft remediation plans are modified, necessary regulatory approvals for the implementation of remediation are obtained, alternative technologies are developed and/or other factors change, there may be revisions to management’s estimates and actual costs may exceed the current environmental accruals. We believe at this time that it is reasonably possible that undiscounted costs associated with these environmental matters may exceed current accruals by amounts that could be, in the aggregate, up to an estimated $24.7 million over the remediation period. It is reasonably possible that our recorded estimate will change in the next 12 months.

Other Contingencies. We are party to various lawsuits, claims, investigations and administrative proceedings that arise in connection with past and current operations. We evaluate such matters on a case-by-case basis and our policy is to vigorously contest any such claims we believe are without merit. We accrue for a legal liability when it is both probable that a liability has been incurred and the amount of the loss is reasonably estimable. Quarterly, in addition to when changes in facts and circumstances require it, we review and adjust these accruals to reflect the impacts of negotiations, settlements, rulings, advice of legal counsel and other information and events pertaining to a particular case. While uncertainties are inherent in the final outcome of such matters and it is presently impossible to determine the actual cost that may ultimately be incurred, we believe that we have sufficiently accrued for such matters and that the ultimate resolution of pending matters will not have a material impact on our consolidated financial position, operating results, or liquidity.