Section 335.170 - Design and Operating Requirements (Waste Piles)(a) A waste pile (except for an existing portion of a waste pile) must have: (1) a liner that is designed, constructed, and installed to prevent any migration of wastes out of the pile into the adjacent subsurface soil or groundwater 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 groundwater or surface water) during the active life of the facility. The liner must be: (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 operation;(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(C) installed to cover all surrounding earth likely to be in contact with the waste or leachate; and(2) 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 commission will specify design and operating conditions in the permit to ensure that the leachate depth over the liner does not exceed 30 centimeters (one foot). The leachate collection and removal system must be: (A) constructed of materials that are: (i) chemically resistant to the waste managed in the pile and the leachate expected to be generated; and(ii) of sufficient strength and thickness to prevent collapse under the pressures exerted by overlaying wastes, waste cover materials, and by any equipment used at the pile; and(B) designed and operated to function without clogging through the scheduled closure of the waste pile.(b) The owner or operator will be exempted from the requirements of subsection (a) of this section if the commission finds, based on a demonstration by the owner or operator, the alternate design and operating practices, together with location characteristics, will prevent the migration of any hazardous constituents into the groundwater or surface water at any future time. In deciding whether to grant an exemption, the commission will consider: (1) the nature and quantity of the wastes;(2) the proposed alternate design and operation;(3) the hydrogeologic setting of the facility, including attenuative capacity and thickness of the liners and soils present between the pile and groundwater or surface water; and(4) all other factors which would influence the quality and mobility of the leachate produced and the potential for it to migrate to groundwater or surface water.(c) The owner and 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 comply with the requirements of 40 CFR §264.251(c), as amended through April 4, 2006 (71 FR 16862).(d) The executive director may approve alternative design or operating practices to those specified in subsection (c) of this section if the owner or operator demonstrates to the executive director that such design and operating practices, together with location characteristics:(1) will prevent the migration of any hazardous constituent into the groundwater or surface water at least as effectively as the liners and leachate collection and removal systems specified in subsection (c) of this section; and(2) will allow detection of leaks of hazardous constituents through the top liner at least as effectively.(e) Subsection (c) of this section does not apply to monofills that are granted a waiver by the Commission in accordance with § 335.168(e) of this title (relating to Design and Operating Requirements (Surface Impoundments)).(f) The owner or operator of any replacement waste pile unit is exempt from subsection (c) of this section if:(1) The existing unit was constructed in compliance with the design standards of §3004(o)(1)(A)(i) and (o)(5) of the Resource Conservation and Recovery Act; and(2) There is no reason to believe that the liner is not functioning as designed.(g) 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 least a 100-year storm.(h) The owner or operator must design, construct, operate, and maintain a run-off management system to collect and control at least the water volume from active portions resulting from a 24-hour, 100-year storm.(i) Collection and holding facilities (e.g., tanks or basins) associated with run-on and run-off control systems must be emptied or otherwise managed expeditiously after storms to maintain design capacity of the system.(j) 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.(k) The commission will specify in the permit all design and operating practices that are necessary to ensure that the requirements of this section are satisfied.30 Tex. Admin. Code § 335.170
The provisions of this §335.170 adopted to be effective May 28, 1986, 11 TexReg 2347; amended to be effective February 26, 1996, 21 TexReg 1142; amended to be effective February 21, 2013, 38 TexReg 978