Environmental Matters (Tables)

6 Months Ended

Jun. 30, 2020

Environmental Remediation Obligations [Abstract]

Schedule of Environmental Loss Contingencies by Site

The following table summarizes information regarding liabilities related to environmental sites, which are recorded in other current liabilities and other noncurrent liabilities in NW Natural's balance sheet:



	Current Liabilities						Non-Current Liabilities
	June 30,				December 31,		June 30,				December 31,
In thousands	2020		2019		2019		2020		2019		2019
Portland Harbor site:
Gasco/Siltronic Sediments	$	10,431	$	4,403	$	11,632	$	41,945	$	44,374	$	46,082
Other Portland Harbor	2,434		2,150		2,543		6,228		5,645		6,920
Gasco/Siltronic Upland site	10,979		9,964		14,203		41,878		42,672		43,616
Central Service Center site	—		10		—		—		—		—
Front Street site	10,222		1,051		10,847		1,059		10,150		—
Oregon Steel Mills	—		—		—		179		179		179
Total	$	34,066	$	17,578	$	39,225	$	91,289	$	103,020	$	96,797

Environmental Regulatory Table

The following table presents information regarding the total regulatory asset deferred:



	June 30,						December 31,
In thousands	2020			2019			2019
Deferred costs and interest ⁽¹⁾	$	42,098		$	43,222		$	36,673
Accrued site liabilities ⁽²⁾	124,981			120,226			135,662
Insurance proceeds and interest	(81,146		)	(90,119		)	(79,949		)
Total regulatory asset deferral⁽¹⁾	$	85,933		$	73,329		$	92,386
Current regulatory assets⁽³⁾	4,176			5,089			4,762
Long-term regulatory assets⁽³⁾	81,757			68,240			87,624


⁽¹⁾	Includes pre-review and post-review deferred costs, amounts currently in amortization, and interest, net of amounts collected from customers.


⁽²⁾	Excludes 3.32% of the Front Street site liability, or $0.4 million in 2020 and $0.4 million in 2019, as the OPUC only allows recovery of 96.68% of costs for those sites allocable to Oregon, including those that historically served only Oregon customers.

⁽³⁾

Environmental costs relate to specific sites approved for regulatory deferral by the OPUC and WUTC. In Oregon, NW Natural earns a carrying charge on cash amounts paid, whereas amounts accrued but not yet paid do not earn a carrying charge until expended. It also accrues a carrying charge on insurance proceeds for amounts owed to customers. In Washington, neither the cash paid nor insurance proceeds received accrue a carrying charge. Current environmental costs represent remediation costs management expects to collect from customers in the next 12 months. Amounts included in this estimate are still subject to a prudence and earnings test review by the OPUC and do not include the $5.0 million tariff rider. The amounts allocable to Oregon are recoverable through NGD rates, subject to an earnings test.