NR 664.0552(2)(a)(a) The department may designate a regulated unit (as defined in s. NR 664.0090 (1) (b)) as a CAMU, or may incorporate a regulated unit into a CAMU, if all of the following apply:

NR 664.0552(2)(a)1.1. The regulated unit is closed or closing, meaning it has begun the closure process under s. NR 664.0113 or 665.0113.

NR 664.0552(2)(a)2.2. Inclusion of the regulated unit will enhance implementation of effective, protective and reliable remedial actions for the facility.

NR 664.0552(2)(b)(b) The subchs. F, G and H requirements and the unit-specific requirements of this chapter or ch. NR 665 that applied to the regulated unit will continue to apply to that portion of the CAMU after incorporation into the CAMU.

NR 664.0552(3)(3) The department shall designate a CAMU that will be used for storage or treatment only in accordance with sub. (6). The department shall designate all other CAMUs in accordance with all of the following:

NR 664.0552(3)(b)(b) Waste management activities associated with the CAMU may not create unacceptable risks to humans or to the environment resulting from exposure to hazardous wastes or hazardous constituents.

NR 664.0552(3)(c)(c) The CAMU shall include uncontaminated areas of the facility, only if including the areas for the purpose of managing CAMU-eligible waste is more protective than management of the wastes at contaminated areas of the facility.

NR 664.0552(3)(d)(d) Areas within the CAMU, where wastes remain in place after closure of the CAMU, shall be managed and contained so as to minimize future releases, to the extent practicable.

NR 664.0552(3)(f)(f) The CAMU shall enable the use, when appropriate, of treatment technologies (including innovative technologies) to enhance the long-term effectiveness of remedial actions by reducing the toxicity, mobility or volume of wastes that will remain in place after closure of the CAMU.

NR 664.0552(3)(g)(g) The CAMU shall, to the extent practicable, minimize the land area of the facility upon which wastes will remain in place after closure of the CAMU.

NR 664.0552(4)(4) The owner or operator shall provide sufficient information to enable the department to designate a CAMU in accordance with the criteria in this section. This shall include, unless not reasonably available, information on all of the following:

NR 664.0552(4)(a)(a) The origin of the waste and how it was subsequently managed (including a description of the timing and circumstances surrounding the disposal or release).

NR 664.0552(4)(c)(c) Whether the disposal or release of the waste occurred before or after the land disposal requirements of ch. NR 668 were in effect for the waste listing or characteristic.

NR 664.0552(5)(b)(b) Design, operation, treatment and closure requirements. Except as provided in sub. (7), requirements for CAMU-eligible waste management to include the specification of applicable design, operation, treatment and closure requirements.

NR 664.0552(5)(c)(c) Minimum design requirements. Except as provided in sub. (6), CAMUs into which wastes are placed shall be designed in accordance with all of the following requirements:

NR 664.0552(5)(c)1.1. Unless the department approves alternate requirements under subd. 2., CAMUs that consist of new, replacement or laterally expanded units shall include a composite liner and a leachate collection system that is designed and constructed to maintain less than a 30-cm depth of leachate over the liner. In this section, “composite liner” means a system consisting of 2 components; the upper component shall consist of a minimum 30-mil flexible membrane liner (FML), and the lower component shall consist of at least a 2-foot layer of compacted soil with a hydraulic conductivity of no more than 1x10-7 cm/sec. FML components consisting of high density polyethylene (HDPE) shall be at least 60 mil thick. The FML component shall be installed in direct and uniform contact with the compacted soil component.

NR 664.0552(5)(c)2.2. The department may approve alternate requirements if any of the following apply:

NR 664.0552(5)(c)2.a.a. The department finds that alternate design and operating practices, together with location characteristics, will prevent the migration of any hazardous constituents into the groundwater or surface water at least as effectively as the liner and leachate collection systems in subd. 1.

NR 664.0552(5)(c)2.b.b. The CAMU is to be established in an area with existing significant levels of contamination, and the department finds that an alternative design, including a design that does not include a liner, would prevent migration from the unit that would exceed long-term remedial goals.

NR 664.0552(5)(d)(d) Minimum treatment requirements. Unless the wastes will be placed in a CAMU for storage or treatment only in accordance with sub. (6), CAMU-eligible wastes that, absent this section, would be subject to the treatment requirements of ch. NR 668, and that the department determines contain principal hazardous constituents shall be treated to the standards specified in subd. 3.

NR 664.0552(5)(d)1.1. Principal hazardous constituents are those constituents that the department determines pose a risk to human health and the environment substantially higher than the cleanup levels or goals at the site.