Section 4.266 - [Effective 7/1/2025] Minimum Design and Construction Information(a) A pit permitted under this division shall be designed, built, and maintained as follows. (1) The pit shall contain the material placed in the pit and prevent releases, overflow, or failure.(2) The maximum depth from the natural surface elevation shall not exceed 22 feet.(3) The foundation and interior slopes shall consist of a firm, unyielding base, smooth and free of rocks, debris, sharp edges, or irregularities to prevent the liner's rupture or tear. All interior and exterior surfaces of the pit shall be smooth drum rolled.(4) The pit sides and berms shall have interior and exterior grades no steeper than three horizontal feet to one vertical foot (3H:1V). The top of the berm shall be wide enough to provide adequate room for inspection, maintenance, and any other structural or construction requirements. (A) Fill for berms shall be placed and compacted in continuous lifts with a maximum loose lift thickness of 10 inches, compacted to eight inches.(B) Berm fill shall be compacted to at least 95% of maximum dry density determined by the Standard Proctor (ASTM D698) and at moisture content within +2% to -2% of optimum moisture content as determined by a standard proctor soil test on samples from the source area. One nuclear density test shall be conducted for each 2,500 cubic yards, and the applicant shall provide compaction testing results upon completion.(5) Both primary and secondary liners in a pit shall be geomembrane liners composed of ASTM GRI-13 compliant materials and be impervious, synthetic material that is resistant to ultraviolet light, petroleum hydrocarbons, salts, and acidic and alkaline solutions. Each pit shall incorporate, at a minimum, a liner system as follows: (A) The primary liner shall be constructed with a minimum 60-mil high density polyethylene (HDPE) for any pit under this subsection permitted after July 1, 2025.(B) A leak detection system shall be placed between the primary and secondary geomembrane liners that shall consist of 200-mil biplanar geonet or geo-composite equivalent. The leak detection system shall consist of a properly designed drainage and collection and removal system placed above the secondary geomembrane liner in depressions and sloped to facilitate the earliest possible leak detection. The leak detection system shall be designed with the capability of removing a minimum of 1,000 gallons of leachate per acre per day or an alternative action leakage rate shall be calculated.(C) The secondary liner shall be constructed with a minimum 40-mil HDPE for any pit under this subsection permitted after July 1, 2025. If the depth to groundwater is less than 100 feet below the ground surface, the secondary liner shall include a geosynthetic clay liner.(D) A geotextile (felt) liner shall be placed under the secondary liner and in contact with the prepared ground surface.(6) The edges of all liners shall be anchored in the bottom of a compacted earth-filled trench that is at least 24 inches deep and shall be performed in accordance with the manufacturer's instructions.(7) Field seams in geosynthetic material shall be performed in accordance with the manufacturer's instructions and include the following considerations: (A) Field seams in geosynthetic material shall be minimized and oriented perpendicular to the slope of the berm, not parallel.(B) Prior to field seaming, the operator shall overlap liners a minimum of four to six inches. The operator shall minimize the number of field seams and corners and irregularly shaped areas. There shall be no horizontal seams within five feet of the slope's toe. (C) Qualified personnel shall perform field seam welding and testing. Documented quality assurance/quality control testing reports shall be maintained for the life of the liner.(8) At a point of discharge into or suction from the pit, the operator shall ensure that the liner is protected from excessive hydrostatic force or mechanical damage.(9) All piping and equipment that is in contact with the liner shall be secured to prevent liner wear and damage. (10) There shall be no penetrations of the liner system.(11) The pit shall be designed to prevent run-on of any non-contact stormwater, precipitation, or surface water. The pit shall be surrounded by a berm, ditch, or other diversion to prevent run-on of any non-contact stormwater, precipitation, or surface water.(12) The pit shall be designed to operate with a minimum two feet of freeboard plus the capacity to contain the volume of precipitation from a 25-year, 24-hour rainfall event.(b) Tanks and treatment equipment shall be located within a secondary containment system.(c) A permit application for off-lease commercial recycling of fluid shall include the layout and design of the facility by including a plat drawn to scale with north arrow to top of the map showing the location and information on the design and size of all receiving, processing, and storage areas and all equipment, tanks, silos, monitor wells, dikes, fences, and access roads.(d) A permit application for off-lease commercial recycling of fluid also shall include: (1) a description of the type and thickness of liners (e.g., fiberglass, steel concrete), if any, for all tanks, silos, pits, and storage areas/cells;(2) for storage areas where tanks and/or liners are not used, credible engineering and/or geologic information demonstrating that tanks or liners are not necessary for the protection of surface and subsurface water;(3) a map view and two perpendicular cross-sectional views of pits and/or storage areas/cells to be constructed, showing the bottom, sides, and dikes, showing the dimensions of each;(4) a plan to control and manage storm water runoff and to retain incoming wastes during wet weather, including the location and dimensions of berms and/or storage basins that would collect stormwater from the facility, at a minimum, during a 25-year, 24-hour rainfall event, and all calculations made to determine the required capacity and design; and(5) a plan for the installation of monitoring wells at the facility.16 Tex. Admin. Code § 4.266
The provisions of this §4.266 adopted to be effective April 15, 2013, 38 TexReg 2334; Amended by Texas Register, Volume 50, Number 01, January 3, 2025, TexReg 0096, eff. 7/1/2025