4. Landfill and Environmental Remediation Liabilities

Liabilities for landfill and environmental remediation costs as of December 31 are presented in the table below (in millions):


	2017						2016
			Environmental						Environmental
	Landfill		Remediation		Total		Landfill		Remediation		Total
Current (in accrued liabilities)	$	128	$	28	$	156	$	119	$	28	$	147
Long-term		1,547		223		1,770		1,457		218		1,675
	$	1,675	$	251	$	1,926	$	1,576	$	246	$	1,822

The changes to landfill and environmental remediation liabilities for the year ended December 31, 2017 are reflected in the table below (in millions):


			Environmental
	Landfill		Remediation
December 31, 2016	$	1,576	$	246
Obligations incurred and capitalized		69		—
Obligations settled		(105)		(21)
Interest accretion		92		4
Revisions in estimates and interest rate assumptions (a) (b)		33		23
Acquisitions, divestitures and other adjustments		10		(1)
December 31, 2017	$	1,675	$	251

(a)

The amount reported for our landfill liabilities includes (i) a net increase of $19 million related to our year-end annual review of landfill final capping, closure and post-closure obligations and (ii) an increase of $12 million primarily for enhancements to our gas and leachate collection systems at certain closed landfills.

(b)

Our environmental remediation liabilities include $11 million of charges to adjust our subsidiary’s estimated potential share of an environmental remediation liability and related costs for a closed site in Harris County, Texas, as discussed in Note 10.

Our recorded liabilities as of December 31, 2017 include the impacts of inflating certain of these costs based on our expectations of the timing of cash settlement and of discounting certain of these costs to present value. Anticipated payments of currently identified environmental remediation liabilities, as measured in current dollars, are $28 million in 2018, $23 million in 2019, $66 million in 2020, $36 million in 2021, $11 million in 2022 and $87 million thereafter.

At several of our landfills, we provide financial assurance by depositing cash into restricted trust funds or escrow accounts for purposes of settling final capping, closure, post-closure and environmental remediation obligations. Generally, these trust funds are established to comply with statutory requirements and operating agreements. See Notes 16 and 18 for additional information related to these trusts.