1. (1) The regulations in this section apply to owners and operators of facilities that place, store or treat hazardous waste in piles, except as section 373-2.1(a) of this Subpart provides otherwise.
2. (2) The regulations in this section do not apply to owners and operators of waste piles that are closed with wastes left in place. Such waste piles are subject to regulation under 373-2.14 of this Subpart (secure landburial facilities).

3. (3) The owner or operator of any waste pile that is inside or under a structure that provides protection from precipitation, so that neither runoff nor leachate is generated, is not subject to regulation under subdivision (b) of this section or under section 373-2.6 of this Subpart, provided that:

   1. (i) liquids or materials containing free liquids are not placed in the pile;
   2. (ii) the pile is protected from surface water run-on by the structure or in some other manner;
   3. (iii) the pile is designed and operated to control dispersal of waste by wind, where necessary, by means other than wetting; and

   4. (iv) the pile will not generate leachate through decomposition or other reactions. Note:

      Note:

      Operation of a waste pile may be subject to Part 376, Land Disposal Restrictions of this Title.

      (b) Design and operating requirements.

4. (1) A waste pile (except for an existing portion of a waste pile) must have:

   1. (i) a liner that is designed, constructed and installed to prevent any migration of wastes out of the pile into the adjacent subsurface soil or ground water or surface water at any time during the active life (including the closure period) of the waste pile. The liner may be constructed of materials that may allow waste to migrate into the liner itself (but not into the adjacent subsurface soil or ground water or surface water) during the active life of the facility. The liner must be:

      1. (a) constructed of materials that have appropriate chemical properties and sufficient strength and thickness to prevent failure due to pressure gradients (including static head and external hydrogeologic forces), physical contact with the waste or leachate to which they are exposed, climatic conditions, the stress of installation and the stress of daily operations;
      2. (b) placed upon a foundation or base capable of providing support to the liner and resistance to pressure gradients above and below the liner to prevent failure of the liner due to settlement, compression or uplift; and
      3. (c) installed to cover all surrounding earth likely to be in contact with the waste or leachate; and

   2. (ii) a leachate collection and removal system immediately above the liner that is designed, constructed, maintained and operated to collect and remove leachate from the pile. The commissioner will specify design and operating conditions in the permit to ensure that the leachate depth over the liner does not exceed 30 cm (one foot). The leachate collection and removal system must be:

      1. (a) constructed of materials that are:

         1. (1) chemically resistant to the waste managed in the pile and the leachate expected to be generated; and
         2. (2) of sufficient strength and thickness to prevent collapse under the pressure exerted by overlying wastes, waste cover materials, and by any equipment used at the pile; and
      2. (b) designed and operated to function without clogging through the scheduled closure of the waste pile.

5. (2) The owner or operator will be exempt from the requirements of paragraph (1) of this subdivision if the commissioner finds, based on a demonstration by the owner or operator, that alternate design and operating practices, together with location characteristics will prevent the migration of any hazardous constituents (see section 373-2.6[d] of this Subpart) into the ground water or surface water at any future time. In deciding whether to grant an exemption, the commissioner will consider:

   1. (i) the nature and quantity of the wastes;
   2. (ii) the proposed alternate design and operation;
   3. (iii) the hydrogeologic setting of the facility, including alternative capacity and thickness of the liners and soils present between the pile and ground water or surface water; and
   4. (iv) all other factors which would influence the quality and mobility of the leachate produced and the potential for it to migrate to ground water or surface water.

6. (3) The owner or operator of each new waste pile unit, each lateral expansion of a waste pile unit, and each replacement of an existing waste pile unit must install two or more liners and a leachate collection and removal system above and between such liners.

   1. (a) The liner system must include:

      1. (1) a top liner designed and constructed of materials (e.g., a geomembrane) to prevent the migration of hazardous constituents into such liner during the active life and post-closure care period; and
      2. (2) a composite bottom liner, consisting of at least two components. The upper component must be designed and constructed of materials (e.g., a geomembrane) to prevent the migration of hazardous constituents into this component during the active life and post-closure care period. The lower component must be designed and constructed of materials to minimize the migration of hazardous constituents if a breach in the upper component were to occur. The lower component must be constructed of at least three feet (91 cm) of compacted soil material with a hydraulic conductivity of no more than 1 × 10 ^-7 cm/sec.
   2. (b) The liners must comply with clauses (1)(i)(a), (b), and (c) of this subdivision.
   3. (ii) The leachate collection and removal system immediately above the top liner must be designed, constructed, operated, and maintained to collect and remove leachate from the waste pile during the active life and post-closure care period. The commissioner will specify design and operating conditions in the permit to ensure that the leachate depth over the liner does not exceed 30 cm (one foot). The leachate collection and removal system must comply with clauses (3)(iii)(c) and (d) of this subdivision.

   4. (iii) The leachate collection and removal system between the liners, and immediately above the bottom composite liner in the case of multiple leachate collection and removal systems, is also a leak detection system. This leak detection system must be capable of detecting, collecting, and removing leaks of hazardous constituents at the earliest practicable time through all areas of the top liner likely to be exposed to waste or leachate during the active life and post-closure care period. The requirements for a leak detection system in this paragraph are satisfied by installation of a system that is, at a minimum:

      1. (a) constructed with a bottom slope of one percent or more;
      2. (b) constructed of granular drainage materials with a hydraulic conductivity of 1 × 10^-2 cm/sec or more and a thickness of 12 inches (30.5 cm) or more; or constructed of synthetic or geonet drainage materials with a transmissivity of 3 × 10^-5 m²/sec or more;
      3. (c) constructed of materials that are chemically resistant to the waste managed in the waste pile and the leachate expected to be generated, and of sufficient strength and thickness to prevent collapse under the pressures exerted by overlying wastes, waste cover materials, and equipment used at the waste pile;
      4. (d) designed and operated to minimize clogging during the active life and post-closure care period; and
      5. (e) constructed with sumps and liquid removal methods (e.g., pumps) of sufficient size to collect and remove liquids from the sump and prevent liquids from backing up into the drainage layer. Each unit must have its own sump(s). The design of each sump and removal system must provide a method for measuring and recording the volume of liquids present in the sump and of liquids removed.
   5. (iv) The owner or operator shall collect and remove pumpable liquids in the leak detection system sumps to minimize the head on the bottom liner.
   6. (v) The owner or operator of a leak detection system that is not located completely above the seasonal high water table must demonstrate that the operation of the leak detection system will not be adversely affected by the presence of ground water.

   (i)

7. (4) The commissioner may approve alternative design or operating practices to those specified in paragraph (3) of this subdivision if the owner or operator demonstrates to the commissioner that such design and operating practices, together with location characteristics:

   1. (i) will prevent the migration of any hazardous constituent into the ground water or surface water at least as effectively as the liners and leachate collection and removal systems specified in paragraph (3) of this subdivision; and
   2. (ii) will allow detection of leaks of hazardous constituents through the top liner at least as effectively.
8. (5) Paragraph (3) of this subdivision does not apply to monofills that are granted a waiver by the commissioner in accordance with section 373-2.11(b)(5) of this Subpart.

9. (6) The owner or operator of any replacement waste pile unit is exempt from paragraph (3) of this subdivision if:

   1. (i) the existing unit was constructed in compliance with the design standards of section 3004(o)(1)(A)(i) and (o)(5) of the Resource Conservation and Recovery Act (see section 370.1[e] of this Title); and
   2. (ii) there is no reason to believe that the liner is not functioning as designed.
10. (7) The owner or operator must design, construct, operate and maintain a run-on control system capable of preventing flow onto the active portion of the pile during peak discharge from at lest a 25-year storm.
11. (8) The owner or operator must design, operate and maintain a runoff management system to collect and control at least the water volume resulting from a 24-hour, 25-year storm.
12. (9) Collection and holding facilities (e.g., tanks or basins) associated with run-on and runoff control systems must be emptied or otherwise managed expeditiously after storms to maintain design capacity of the system.
13. (10) If the pile contains any particulate matter which may be subject to wind dispersal, the owner or operator must cover or otherwise manage the pile to control wind dispersal.
14. (11) The commissioner will specify in the permit all design and operating practices that are necessary to ensure that the requirements of this subdivision are satisfied.
15. (c) Double-lined piles which are not applicable to paragraph (a)(3) of this section are not exempt from section 373-2.6 ground-water protection requirements.

16. (d) [Reserved]

    1. (1) During construction or installation, liners (except in the case of existing portions of piles exempt from paragraph [b][1] of this section) and cover systems (e.g., membranes, sheets or coatings) must be inspected for uniformity, damage and imperfections (e.g., holes, cracks, thin spots or foreign materials). Immediately after construction or installation:

       1. (i) synthetic liners and covers must be inspected to ensure tight seams and joints and the absence of tears, punctures and blisters;
       2. (ii) soil-based and admixed liners and covers must be inspected for imperfections, including lenses, cracks, channels, root holes or other structural nonuniformities that may cause an increase in the permeability of the liner or cover.

    2. (2) While a waste pile is in operation, it must be inspected weekly and after storms to detect evidence of any of the following:

       1. (i) deterioration, malfunctions, or improper operation of run-on and runoff control systems;
       2. (ii) proper functioning of wind dispersal control systems, where present; and
       3. (iii) the presence of leachate in and proper functioning of leachate collection and removal systems, where present.

    3. (3) An owner or operator required to have a leak detection system under paragraph (b)(3) of this section must record the amounts of liquids removed from each leak detection system sump at least once each week during the active life and closure period.

       (f) Special requirements for ignitable or reactive waste.

       Ignitable or reactive waste must not be placed in a waste pile unless the waste and waste pile satisfy all applicable requirements in Part 376 of this Title and:

    4. (1) the waste is treated, rendered or mixed before or immediately after placement in the pile, so that:

       1. (i) the resulting waste, mixture or dissolution of material no longer meets the definition of ignitable or reactive waste under section 371.3(b) or (d) of this Title; and
       2. (ii) section 373-2.2(i)(2) of this Subpart is complied with; or

    5. (2) the waste is managed in such a way that it is protected from any material or conditions which may cause it to ignite or react.

       (g) Special requirements for incompatible wastes.

    6. (1) Incompatible wastes, or incompatible wastes and materials (see Appendix 29 of this Title for examples), must not be placed in the same pile, unless section 373-2.2(i)(2) if this Subpart is complied with.
    7. (2) A pile of hazardous waste that is incompatible with any waste or other material placed nearby in containers, other piles, open tanks or surface impoundments must be separated from the other materials, or protected from them by means of a dike, berm, wall or other device.

    8. (3) Hazardous waste must not be plied on the same base where incompatible wastes or materials were previously piled, unless the base has been decontaminated sufficiently to ensure compliance with section 373-2.2(i)(2) of this Subpart.

       (h) Closure and post-closure care.

    9. (1) At closure, the owner or operator must remove or decontaminate all waste residues, contaminated containment system components (liners, etc.), contaminated subsoils, structures and equipment contaminated with waste and leachate, and manage them as hazardous waste unless section 371.1(d)(4) of this Title applies.

    10. (2) If, after removing or decontaminating all residues and making all reasonable efforts to effect removal or decontamination of contaminated components, subsoild, structures and equipment as required in paragraph (1) of this subdivision, the owner or operator finds that not all contaminated subsoils can be practicably removed or decontaminated, the owner or operator must close the facility and perform post-closure care in accordance with the closure and post- closure care requirements that apply to landfills (see section 373-2.14[f] of this Subpart).

        1. (i) The owner or operator of a waste pile that does not comply with the liner requirements of subparagraph (b)(1)(i) of this section, and is not exempt from them in accordance with paragraph (a)(3) or (b)(2) of this section must:

           1. (a) include, in the closure plan for the pile under section 373-2.7(c) of this Subpart, both a plan for complying with paragraph (1) of this subdivision and a contingent plan for complying with paragraph (2) in case not all contaminated subsoils can be practicably removed at closure; and
           2. (b) prepare a contingent post-closure plan under section 373-2.7(h) of this Subpart for complying with paragraph (2) of this subdivision in case not all contaminated subsoils can be practicably removed at closure.
        2. (ii) The cost estimates calculated under section 373-2.8(c) and (e) of this Subpart for closure and post-closure care of a pile subject to this section must include the costs of complying with the contingent closure plan and the contingent post-closure plan, but are not required to include the cost of expected closure under paragraph (1) of this subdivision.

        (3)

    (e) Monitoring and inspection.

17. (i) Special requirements for hazardous wastes F020, F021, F022, F023, F026 and F027.

    1. (1) Hazardous wastes F020, F021, F022, F023, F026 and F027 must not be placed in waste piles that are not enclosed (the requirements for an enclosed waste pile are described in paragraph [a][3] of this section) unless the owner or operator operates the waste pile in accordance with a management plan for these wastes that is approved by the commissioner pursuant to the standards set out in this paragraph, and in accord with all other applicable requirements of this Subpart. The factors to be considered are:

       1. (i) the volume and the physical and chemical characteristics of the wastes, including their potential to migrate through soil or to volatize or escape into the atmosphere;
       2. (ii) the attenuative properties of underlying and surrounding soils or other materials;
       3. (iii) the mobilizing properties of other materials codisposed with these wastes; and
       4. (iv) the effectiveness of additional treatment, design or monitoring techniques.

    2. (2) The commissioner may determine that additional design, operating and monitoring requirements are necessary for piles managing hazardous wastes F020, F021, F022, F023, F026, and F027 to reduce the possibility of migration of these wastes to ground water, surface water or air to protect human health and the environment.

       (j) Action leakage rate.

    3. (1) The commissioner shall approve an action leakage rate for waste pile units subject to paragraph (b)(3) or (4) of this section. The action leakage rate is the maximum design flow rate that the leak detection system (LDS) can remove without the fluid head on the bottom liner exceeding one foot. The action leakage rate must include an adequate safety margin to allow for uncertainties in the design (e.g., slope, hydraulic conductivity, thickness of drainage material), construction, operation, and location of the LDS, waste and leachate characteristics, likelihood and amounts of other sources of liquids in the LDS, and proposed response actions (e.g., the action leakage rate must allow for decreases in the flow capacity of the system over time resulting from siltation and clogging, rib layover and creep of synthetic components of the system, overburden pressures, etc.).

    4. (2) To determine if the action leakage rate has been exceeded, the owner or operator must convert the weekly flow rate from the monitoring data obtained under paragraph (e)(3) of this section to an average daily flow rate (gallons per acre per day) for each sump. Unless the commissioner approves a different calculation, the average daily flow rate for each sump must be calculated weekly during the active life and closure period.

       (k) Response actions.

    5. (1) The owner or operator of waste pile units subject to paragraph (b)(3) or (4) of this section must have an approved response action plan before receipt of waste. The response action plan must set forth the actions to be taken if the action leakage rate has been exceeded. At a minimum, the response action plan must describe the actions specified in paragraph (2) of this subdivision:

    6. (2) If the flow rate into the leak detection system exceeds the action leakage rate for any sump, the owner or operator must:

       1. (i) notify the commissioner in writing of the exceedence within seven days of the determination;
       2. (ii) submit a preliminary written assessment to the commissioner within 14 days of the determination, as to the amount of liquids, possible location, size, and cause of any leaks, and short-term actions taken and planned;
       3. (iii) determine to the extent practicable the location, size, and cause of any leak;
       4. (iv) determine whether waste receipt should cease or be curtailed, whether any waste should be removed from the unit for inspection, repairs, or controls, and whether or not the unit should be closed;
       5. (v) determine any other short-term and long-term actions to be taken to mitigate or stop any leaks; and
       6. (vi) within 30 days after the notification that the action leakage rate has been exceeded, submit to the commissioner the results of the analyses specified in subparagraphs (iii), (iv), and (v) of this paragraph, the results of actions taken, and actions planned. Monthly thereafter, as long as the flow rate in the leak detection system exceeds the action leakage rate, the owner or operator must submit to the commissioner a report summarizing the results of any remedial actions taken and actions planned.

    7. (3) To make the leak and/or remediation determinations in subparagraphs (2)(iii), (iv) and (v) of this subdivision, the owner or operator must:

       1. (a) assess the source of liquids and amounts of liquids by source;
       2. (b) conduct a fingerprint, hazardous constituent, or other analyses of the liquids in the leak detection system to identify the source of liquids and possible location of any leaks, and the hazard and mobility of the liquid; and
       3. (c) assess the seriousness of any leaks in terms of potential for escaping into the environment; or
       4. (ii) document why such assessments are not needed.

       (i)

(a) Applicability.