(a) Except as provided in subsection (b) of this section, storage of biosolids and/or domestic septage at a land application unit must not exceed 90 days. Storage is allowed only when the following requirements are carried out.
  (1) Written authorization must be obtained from the executive director prior to construction of the storage area.
  (2) The storage area must be operated and maintained to prevent surface water runoff and to prevent a release to groundwater. Discharge of stormwater or wastewater which has come into contact with biosolids and/or domestic septage is prohibited. The storage area shall be designed to collect such runoff. Any runoff collected during the storage of biosolids and/or domestic septage shall be disposed in a manner to prevent a release to groundwater.
  (3) The storage area shall be designed, constructed, and operated in a manner which protects human health and the environment. Biosolids and/or domestic septage shall be stored away from odor receptors in order to prevent off-site dust migration from the storage area and to prevent nuisance odors.
  (4) For biosolids only, the storage area must be lined to prevent a release to groundwater. Natural or artificial liners are required for leachate control. A natural liner or equivalent barrier of one foot of compacted clay with a permeability coefficient of 1 x 10-7 cm/sec or less must be provided. Various flexible synthetic membrane lining materials may be used in lieu of soil liners if prior written approval has been obtained from the executive director. The applicant shall furnish certification by a licensed professional engineer or licensed professional geoscientist that the completed storage area lining meets the appropriate criteria described in this section prior to using the facilities. The certification shall be signed, sealed, and dated by a licensed professional engineer or licensed professional geoscientist.
  (5) The request for the storage area shall outline measures to be taken to minimize vectors and to avoid public health nuisances such as odors.
  (6) The storage area shall be fenced, or other methods shall be used, if necessary, to control access by humans or domestic livestock.
  (7) For biosolids only, berms or dikes shall be constructed to contain the waste without leakage.
  (8) Liquid biosolids and/or domestic septage must be stored in an enclosed vessel.
  (9) Processing of biosolids and/or domestic septage is prohibited unless a permit is obtained from the commission.
  (10) In the event a person who prepares biosolids and/or domestic septage that is land applied or who land applies biosolids and/or domestic septage, is subject to an Odor Control Plan as described in §312.44(j)(4) of this title (relating to Management Practices), that person must comply with the terms of the applicable Odor Control Plan in order to store biosolids and/or domestic septage at a land application unit.
(b) Up to an additional 90 days of storage will be allowed with the prior approval of the appropriate Texas Commission on Environmental Quality (TCEQ) regional office, for reasons associated with application area flooding, saturated soils, or frozen soils.
(c) Staging of biosolids and/or domestic septage on-site, prior to land application, is allowable without executive director approval. Staging of biosolids and/or domestic septage may only occur for a maximum of seven calendar days per each individual staging location within the land application unit. Up to an additional 14 days of staging biosolids and/or domestic septage will be allowed with the prior approval of the appropriate TCEQ regional office, for reasons associated with application area flooding, saturated soils, frozen soils, or equipment failure. Biosolids and/or domestic septage cannot be moved to another staging area to restart the timeframe allowed for staging. Written records of the location of each staging area and timeframe in which biosolids and/or domestic septage were staged shall be retained by the operator and be readily available for review by a TCEQ representative. The operator shall stage the biosolids and/or domestic septage away from odor receptors in order to prevent off-site dust migration from the staging area and to prevent nuisance odors.
(d) Recordkeeping. The person who stores or stages biosolids and/or domestic septage shall develop the following information and shall retain the information for five years:
  (1) the date, volume, and type of material deposited at the storage facility or staging area;
  (2) the date, volume, and type of material removed from the storage facility or staging area; and
  (3) if the material was not land applied on-site, the permit or registration number, location, and operator of the facility where the material that was removed from the storage facility or staging area was deposited.

Source Note: The provisions of this §312.50 adopted to be effective October 13, 1995, 20 TexReg 7840; amended to be effective September 1, 2003, 28 TexReg 6300; amended to be effective October 2, 2014, 39 TexReg 7756; amended to be effective April 23, 2020, 45 TexReg 2542