XML 51 R35.htm IDEA: XBRL DOCUMENT v3.21.2
Environmental Matters
 6 Months Ended
Jun. 30, 2021
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 LiabilitiesNon-Current Liabilities
June 30,December 31,June 30,December 31,
In thousands202120202020202120202020
Portland Harbor site:
Gasco/Siltronic Sediments$6,658 $10,431 $7,596 $41,652 $41,945 $43,725 
Other Portland Harbor2,195 2,434 1,942 6,588 6,228 7,020 
Gasco/Siltronic Upland site12,442 10,979 14,887 38,401 41,878 40,250 
Front Street site1,219 10,222 3,816 975 1,059 1,107 
Oregon Steel Mills— — — 179 179 179 
Total$22,514 $34,066 $28,241 $87,795 $91,289 $92,281 
Environmental Regulatory Table
The following table presents information regarding the total regulatory asset deferred:
June 30,December 31,
In thousands202120202020
Deferred costs and interest (1)
$50,604 $42,098 $44,516 
Accrued site liabilities (2)
110,237 124,981 120,352 
Insurance proceeds and interest(69,730)(81,146)(69,253)
Total regulatory asset deferral(1)
$91,111 $85,933 $95,615 
Current regulatory assets(3)
5,688 4,176 4,992 
Long-term regulatory assets(3)
85,423 81,757 90,623 
(1)     Includes pre-review and post-review deferred costs, amounts currently in amortization, and interest, net of amounts collected from customers.
(2)    Excludes 3.3% of the Front Street site liability as the OPUC only allows recovery of 96.7% of costs for those sites allocable to Oregon, including those that historically served only Oregon customers. Amounts excluded from regulatory assets were $0.1 million at June 30, 2021, $0.4 million at June 30, 2020, and $0.2 million at December 31, 2020,
(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.