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):


	2018						2017
			Environmental						Environmental
	Landfill		Remediation		Total		Landfill		Remediation		Total
Current (in accrued liabilities)	$	143	$	26	$	169	$	128	$	28	$	156
Long-term		1,617		211		1,828		1,547		223		1,770
	$	1,760	$	237	$	1,997	$	1,675	$	251	$	1,926

The changes to landfill and environmental remediation liabilities for the year ended December 31, 2018 are reflected in the table below (in millions):


			Environmental
	Landfill		Remediation
December 31, 2017	$	1,675	$	251
Obligations incurred and capitalized		83		—
Obligations settled		(108)		(26)
Interest accretion		95		5
Revisions in estimates and interest rate assumptions (a) (b)		(3)		9
Acquisitions, divestitures and other adjustments (c)		18		(2)
December 31, 2018	$	1,760	$	237

(a)

The amount reported for our landfill liabilities includes a net decrease of $15 million primarily related to our year-end annual review of landfill final capping, closure and post-closure obligations partially offset by an increase of $12 million due to the acceleration of the expected timing of capping activities for a landfill. See Note 11 for discussion of the impairment charge related to this landfill.

(b)

The amount reported for our environmental remediation liabilities includes changes in cost estimates associated with environmental remediation projects resulting in an increase in the required obligation. These charges were partially offset by a decrease of $3 million in our environmental remediation liabilities due to an increase in the risk-free discount rate used to measure our liabilities from 2.5% at December 31, 2017 to 2.75% at December 31, 2018.

(c)

The amount reported for our landfill liabilities includes an increase of $27 million due to landfill acquisitions partially offset by landfill divestitures and other adjustments.

Our recorded liabilities as of December 31, 2018 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 $26 million in 2019, $19 million in 2020, $65 million in 2021, $37 million in 2022, $13 million in 2023 and $81 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.