(a) The facility owner or operator shall submit his closure plan to the agency for approval with the application for registration.
(b) In the closure plan, the facility owner or operator shall address the following objectives and indicate how they will be achieved:
  (1) removal and decontamination of all structures, equipment, or improvements which will no longer be utilized at the facility;
  (2) removal and proper disposal or treatment and reuse of all petroleum-substance wastes from the facility; and
  (3) removal or treatment of any petroleum-substance waste and petroleum-substance waste constituents which exist above the established cleanup levels that have been released from the facility into the soil, groundwater, or surface water.
(c) During the closure period, the facility owner or operator of a petroleum-substance treatment facility shall:
  (1) continue the contaminant assessment or corrective action at the facility as directed by the agency;
  (2) maintain the run-on and run-off control systems required under §334.502 of this title (relating to Design and Operating Requirements of Stockpiles and Land Surface Treatment Units);
  (3) control wind dispersal of particulate matter which may be subject to wind dispersal.
(d) When closure is completed, the facility owner or operator shall submit to the agency for approval certification both by the facility owner or operator and by an independent qualified hydro geologist, geologist, or an independent registered professional engineer, that the facility has been closed in accordance with the specifications in the approved closure plan.
(e) The facility owner or operator shall prepare a written estimate, in current dollars, of the cost of closing the facility in accordance with the closure plan as specified in subsections (a) and (b) of this section. The closure cost estimate shall equal the cost of closing at the point in the facility's operating life when the extent and manner of its operation would make closure the most expensive, as indicated by its closure plan. The closure cost estimate shall be based on the costs to the facility owner or operator of hiring a third party to close the facility. A third party is a party who is neither a parent nor a subsidiary for the facility owner or operator. Notwithstanding other closure costs, such estimate shall also include the costs associated with third party removal, shipment off-site, and treatment or disposal off-site of the following wastes to an authorized storage, treatment, or disposal facility:
  (1) maximum inventory of wastes possible in storage and/or treatment units;
  (2) any contaminated soils, groundwater, or surface water generated as a result of releases at the site;
  (3) wastes generated as a result of closure activities;
  (4) contaminated storm water or leachate.
(f) The closure cost estimate may not incorporate a positive cost that may be realized by the sale of petroleum-substance wastes, facility structures or equipment, land, or other facility assets at the time of partial or final closures rather than or in addition to waste disposal and clean-up costs. The facility owner or operator may also not incorporate a zero cost for petroleum-substance waste that might have economic value rather than the waste disposal cost.
(g) The facility owner or operator shall revise the closure cost estimate whenever a change in the closure plan increases the cost of closure. The revised closure cost estimate must be adjusted for inflation as specified in Chapter 37, Subchapter B of this title (relating to Financial Assurance Requirements for Closure, Post Closure, and Corrective Action).
(h) The facility owner or operator shall keep the following at the facility during the operating life of the facility: the latest closure cost estimate prepared in accordance with subsections (e) and (f) of this section and, when this estimate has been adjusted for inflation, the latest adjusted closure cost estimate.
(i) For the remaining financial assurance requirements, see Chapter 37, Subchapter K of this title (relating to Financial Assurance Requirements for Class A or B Petroleum-Substance Contaminated Soil Storage, Treatment, or Reuse Facilities).

Source Note: The provisions of this §334.508 adopted to be effective December 27, 1996, 21 TexReg 12177; amended to be effective March 21, 2000, 25 TexReg 2390; amended to be effective November 23, 2000, 25 TexReg 11442