NR 756.07(1)(a)(a) For the purpose of determining the amount of proof of financial responsibility that is required under s. NR 756.06, a person required to submit proof shall submit the estimated costs together with all necessary justification and documentation, as required by the department, to the department for approval as part of the initial request for approval of the plan and compliance schedule. The costs shall be based on a third party performing the work and reported on a per unit basis, as applicable. The source of estimates shall be indicated. NR 756.07(1)(b)(b) For the planned costs under s. NR 756.04 (2) (b) 1. and 3., the person required to submit proof shall estimate the annual cost in current dollars for each year of the plan and compliance schedule proof period. NR 756.07(1)(c)(c) For the additional costs under s. NR 756.04 (2) (b) 2. and 4., the person required to submit proof shall estimate costs in current dollars and shall multiply the sum of the costs by a percentage that is provided by the department and determined by the department based on all of the following criteria, as applicable: NR 756.07(1)(c)1.1. The cost of response actions taken to address contaminated sediments at the site and the cost of response actions that are part of any approved plan to address contaminated sediments for the site. NR 756.07(1)(c)2.2. The assessment of the vulnerability of any engineering controls and structural impediments to any occurrences, including third-party actions and events, that may affect the protectiveness of any engineering controls and the completion of the goals established in the plan and compliance schedule. NR 756.07(1)(c)3.d.d. Cap complexity, including use of geosynthetics, armoring, and amendments. NR 756.07(2)(a)(a) Prior to submitting a new cost estimate under par. (b), the person required to submit proof shall request in writing that the department review the length of the plan and compliance schedule and the length of the proof period for each applicable financial responsibility requirement. The department shall respond within 60 days of the request and shall provide any extensions in writing. NR 756.07(2)(b)(b) The person required to submit proof shall prepare and submit to the department a new cost estimate during the proof period at all of the following times: NR 756.07(2)(b)1.1. Once every 5 years, unless the costs are revised within the 5-year period as required under subd. 2. The new cost estimate shall use current dollars. NR 756.07(2)(b)2.2. When any change in site design or operation is approved by the department in writing. NR 756.07(3)(3) Costs for engineering control maintenance. Cost estimates for engineering control maintenance shall include all of the following, as applicable: NR 756.07(3)(a)(a) Sampling, surveying, and monitoring, including bathymetry survey, core sampling, pore water measurements, poling, surface water sampling, event-based monitoring, regular monitoring, and comparison with previous monitoring occurrences. For the purposes of preparing cost estimates, all regular monitoring requirements specified in the plan and compliance schedule shall apply over the entire proof period. NR 756.07(3)(b)(b) Modeling, including transport modeling and conceptual site modeling. NR 756.07(3)(d)(d) Repair and replacement of engineering controls. The expected operating life of all engineering controls shall be specified in the plan and compliance schedule. As each of these features reach the end of their anticipated operating life, the cost of their replacement shall be added to the estimate for the appropriate year of the proof period. NR 756.07(4)(4) Costs for site investigation and remediation following structural impediment removal. Costs estimates for inspection, the investigation of the extent of residual contamination, and performance of any necessary response actions that are needed following the removal of a structural impediment shall include all of the following, as applicable: