2. Landfill and Environmental Remediation Liabilities

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


	September 30, 2018						December 31, 2017
			Environmental						Environmental
	Landfill		Remediation		Total		Landfill		Remediation		Total
Current (in accrued liabilities)	$	131	$	27	$	158	$	128	$	28	$	156
Long-term		1,622		210		1,832		1,547		223		1,770
	$	1,753	$	237	$	1,990	$	1,675	$	251	$	1,926

The changes to landfill and environmental remediation liabilities for the nine months ended September 30, 2018 are reflected in the table below (in millions):


			Environmental
	Landfill		Remediation
December 31, 2017	$	1,675	$	251
Obligations incurred and capitalized		62		—
Obligations settled		(71)		(18)
Interest accretion		71		4
Revisions in estimates and interest rate assumptions (a) (b)		7		2
Acquisitions, divestitures and other adjustments		9		(2)
September 30, 2018	$	1,753	$	237

(a)

The amount reported for our landfill liabilities includes an increase of $11 million due to the acceleration of the expected timing of capping activities for a landfill. See Note 10 for discussion of the impairment charge related to this landfill.

(b)

The amount reported for our environmental remediation liabilities includes the impact of an increase in the risk-free discount rate used to measure our liabilities from 2.5% at December 31, 2017 to 3.0% at September 30, 2018, resulting in a decrease of $5 million to our environmental remediation liabilities.

At several of our landfills, we provide financial assurance by depositing cash into restricted trust funds or escrow accounts for purposes of demonstrating our ability to meet our final capping, closure, post-closure and environmental remediation obligations. Generally, these trust funds are established to comply with statutory requirements and operating agreements. See Note 14 for additional information related to these trusts.