Northwest Natural Holding Co

Properties and Facilities

NW Natural owns, or previously owned, properties and facilities that are currently being investigated that may require environmental remediation and are subject to federal, state, and local laws and regulations related to environmental matters. These laws and regulations may require expenditures over a long time frame to address certain environmental impacts. Estimates of liabilities for environmental costs are difficult to determine with precision because of the various factors that can affect their ultimate disposition. These factors include, but are not limited to, the following:

•the complexity of the site;

•changes in environmental laws and regulations at the federal, state, and local levels;

•the number of regulatory agencies or other parties involved;

•new technology that renders previous technology obsolete, or experience with existing technology that proves ineffective;

•the level of remediation required;

•variations between the estimated and actual period of time that must be dedicated to respond to an environmentally-contaminated site; and

•the application of environmental laws that impose joint and several liabilities on all potentially responsible parties.

NW Natural has received recovery of a portion of such environmental costs through insurance proceeds, seeks the remainder of such costs through customer rates, and believes recovery of these costs is probable. In both Oregon and Washington, NW Natural has mechanisms to recover expenses. Oregon recoveries are subject to an earnings test. See Part II, Item 7, "Results of Operations—Regulatory Matters—Rate Mechanisms—Environmental Cost Deferral and Recovery", and Note 2 and Note 17 of the Consolidated Financial Statements in Item 8 of this report for more information.

Greenhouse Gas Matters

For information concerning greenhouse gas matters, see Part II, Item 7, “Results of Operations—Environmental Regulation and Legislation Matters.”