l. Intangible Assets m. Environmental Remediation n. Retirement Benefits o. Conditional Asset Retirement Obligations 48 CAROs associated with owned properties are based on estimated costs necessary for the legally required removal or remediation of various regulated materials, primarily asbestos disposal and radiological decontamination of an ordnance manufacturing facility. For leased properties, CAROs are based on the estimated cost of contractually required property restoration. Conditional asset retirement obligations ("CAROs") are legal obligations associated with the retirement of long-lived assets. These liabilities are initially recorded at fair value and the expected asset retirement costs are capitalized by increasing the carrying amount of the related assets by the same amount as the liability. Asset retirement costs are subsequently depreciated over the useful lives of the related assets. Subsequent to initial recognition, the Company records period-to-period changes in the CARO liability resulting from the passage of time and revisions to either the timing or the amount of the estimate of the undiscounted cash flows. The Company discontinued future benefit accruals for the defined benefit pension plans in 2009. The Company provides medical and life insurance benefits ("postretirement benefits") to certain eligible retired employees, with varied coverage by employee group. Annual charges are made for the cost of the plans, including interest costs on benefit obligations, and net amortization and deferrals, increased or reduced by the return on assets. The Company also sponsors a defined contribution 401(k) plan and participation in the plan is available to all employees (see Note 7). At the time a liability is recorded for future environmental costs, the Company records an asset for estimated future recoveries that are estimable and probable. Some of the Company’s environmental costs are eligible for future recovery in the pricing of its products and services to the U.S. government and under existing third party agreements. The Company considers the recovery probable based on the Global Settlement, U.S. government contracting regulations, and its long history of receiving reimbursement for such costs (see Notes 8(b) and 8(c)). The Company expenses, on a current basis, recurring costs associated with managing hazardous substances and contamination in ongoing operations. The Company reviews on a quarterly basis estimated future remediation costs and has an established practice of estimating environmental remediation costs over a fifteen-year period, except for those environmental remediation costs with a specific contractual term. Environmental liabilities at the Baldwin Park Operable Unit ("BPOU") site are currently estimated through the term of the project agreement, which expires in May 2027. In establishing reserves, the most probable estimated amount is used when determinable, and the minimum amount is used when no single amount in the range is more probable. Environmental reserves include the costs of completing remedial investigation and feasibility studies, remedial and corrective actions, regulatory oversight costs, the cost of operation and maintenance of the remedial action plan, and employee compensation costs for employees who are expected to devote a significant amount of time to remediation efforts. Calculation of environmental reserves is based on the evaluation of currently available information with respect to each individual environmental site and considers factors such as existing technology, presently enacted laws and regulations, and prior experience in remediation of contaminated sites. Such estimates are based on the expected costs of investigation and remediation and the likelihood that other potentially responsible parties will be able to fulfill their commitments at sites where the Company may be jointly or severally liable. Identifiable intangible assets, such as patents, trademarks, and licenses are recorded at cost or when acquired as part of a business combination at estimated fair value. Identifiable intangible assets are amortized based on when they provide the Company economic benefit, or using the straight-line method, over their estimated useful life. Amortization periods for identifiable intangible assets range from 7 years to 30 years. There can be no assurance that the Company’s estimates and assumptions made for purposes of its goodwill impairment testing will prove to be accurate predictions of the future. If the Company’s assumptions and estimates are incorrect, the Company may be required to record goodwill impairment charges in future periods. the fair value of a reporting unit is less than its carrying amount, the Company will proceed to the quantitative ("Step One") analysis to determine the existence and amount of any goodwill impairment. The Company may also perform a Step One analysis from time to time to augment its qualitative assessment. The Company evaluated goodwill using a Step Zero analysis as of October 1, 2020 and 2019, and determined that goodwill was not impaired.