For the Years Ended December 31, 2011, 2010 and 2009
Other long-term liabilities consist of the following:
| At December 31, | ||
| In thousands | 2011 | 2010 |
| Supplemental employees' retirement plan (SERP) | $ 11,546 | $ 10,979 |
| Deferred compensation | 11,556 | 11,903 |
| Long-term incentive plan | 5,089 | 4,705 |
| Noncurrent income taxes payable | 4,313 | 4,002 |
| Environmental remediation liability | 9,941 | 11,066 |
| Other | 14,440 | 8,862 |
| Total | $ 56,885 | $ 51,517 |
Disclosures regarding the assumptions used in the determination of the SERP liabilities are included in Note 14, Pension Plans. Discussions of our environmental remediation liabilities are in Note 10, Environmental Costs, and Note 16, Commitments and Contingencies.
The Company maintains a non-qualified deferred compensation plan for certain of its employees as well as a non-qualified deferred compensation plan for its Board of Directors. Generally, participants in these plans have the ability to defer a certain amount of their compensation, as defined in the agreement. The deferred compensation liability will be paid out either upon retirement or as requested based upon certain terms in the agreements and in accordance with Internal Revenue Code Section 409A.