Section 20-6101. PERMANENT CLOSURE OR CHANGE-IN-SERVICE

 

6101.1When an UST system is to be permanently closed or is to undergo a change-in-service, the owner, or operator of the UST system, a responsible party or a remediating party shall comply with each of the requirements of this section.

 

6101.2The continued use of an UST system to store a non-regulated substance shall be considered a change-in-service. Before each change-in-service, the owner, operator, a responsible party or a remediating party shall empty and clean the tank by removing and properly disposing of all liquid and all accumulated sludge in compliance with any and all applicable laws and regulations.

 

6101.3Not less than two (2) weeks before beginning either a permanent closure or a change-in-service of an UST system, the owner and operator, a responsible party or a remediating party shall notify the Director, by submitting a UST/LUST Activity Notification form. Notice shall not be required if such action is taken pursuant to a corrective action plan approved by the Director.

 

6101.4In complying with the requirements of this section, owners or operators of UST systems, a responsible party or a remediating party shall follow a code of practice developed by a nationally recognized association or independent testing laboratory, as specified by the Director.

 

6101.5Before a UST system is removed from the ground, the owner, operator, a responsible party or a remediating party shall empty the UST system, if not already emptied during the temporary closure period, and clean it by removing and properly disposing of all liquids and all accumulated sludges in compliance with any and all applicable laws and regulations.

 

6101.6For each UST system that is to be closed permanently, the owner, operator, a responsible party or a remediating party shall provide notice to the Director as provided in § 5603, and then remove the tank from the ground, unless a tank removal variance is granted by the Director, pursuant to § 6101.7.

 

6101.7An owner, operator, a responsible party or a remediating party may apply for a tank removal variance by submitting the following documents:

 

(a)A written request for a tank removal variance;

 

(b)Written certification of the existence of the conditions stated in § 6101.7, with supporting documentation, from a registered professional engineer certified by the District of Columbia or a registered professional engineer certified in any of the states of Region III of the Environmental Protection Agency who has secured reciprocal certification in the District of Columbia;

 

(c)A Tank Interior Inspection report or the results of analysis of soil borings taken from soil adjacent to the tank if the interior cannot be inspected; and

 

(d)A Closure Assessment report.

 

6101.8A tank removal variance may be granted, in the discretion of the Director, when removal of the tank is likely to cause substantial structural damage to buildings or other improvements on the property, or there are other compelling circumstances which make removal of the tank infeasible, however, the owner, operator, a responsible party or a remediating party shall comply with all other requirements of this section and § 5600.14. Where a variance is granted, the tank shall be emptied, cleaned and filled with an inert solid material.

 

6101.9Before permanent closure or a change-in-service of a UST system is completed or a tank removal variance is granted the owner, or operator of the UST system, a responsible party or a remediating party shall conduct a Closure Assessment of the excavation zone to test for the presence of a release in the areas around the UST system where contamination is most likely to be present.

 

6101.10In selecting sample types, sample locations, and measurement methods for the Closure Assessment, the owner, operator, a responsible party or a remediating party shall consider the method of closure, the nature of the stored substance, the type of backfill, the depth to ground-water, and other factors appropriate for identifying the presence of a release and shall comply with any requirements of the Director pertaining to the number of samples and the location of soil borings or ground-water monitoring wells.

 

6101.11If contaminated soils or contaminated ground water, or vapor emissions, in excess of the mandatory clean-up criteria of §§ 6203.9(a), 6203.13 and 6204.1, are discovered during the Closure Assessment, the owner, or operator, a responsible party or a remediating party shall begin corrective action in accordance with the applicable provisions of Chapter 62, except as provided in §§ 6101.13 and 6101.14.

 

6101.12No contaminated soils, excavated during removal of a UST or in undertaking corrective action, shall be stockpiled on site. Soil that has been tested and that does not contain any contaminants shall be placed upon and covered with plastic as a soil erosion control measure. Contaminated soil shall be treated or properly disposed of at an approved facility. When approved by the Director, excavated soils may be stockpiled at the excavation site for no more than ten (10) business days pending completion of testing and analysis for contaminants.

 

6101.13No contaminated soils that exceed Tier 1 risk-based screening levels as set forth in § 6209 and that are excavated (taken from the ground) during the tank removal shall be returned to the excavation pit or used on-site without treatment.

 

6101.14At tank removal, the owner, operator, a responsible party or a remediating party shall remove, treat and properly dispose of at an approved facility:

 

(a)Grossly contaminated soils to the maximum extent practicable as determined by the Director; and

 

(b)Contaminated soils, as set forth in § 6101.13 or that have the potential to cause contaminants to leach to ground water.

 

6101.15In the case of a release of a regulated substance, an owner, an operator, another responsible party or a remediating party shall evaluate the UST system and excavation zone for permanent closure at the excavation depths and screening levels described in this section:

 

(a)After removing contaminated soils to a depth of no more than five (5) feet below the tank bottom and a width of no more than five (5) feet from the sides of the tank, if the levels of chemicals of concern in the soil do not violate the District's Tier 1 screening levels set forth in § 6209, and there is no other visible evidence of contamination (such as free product or vapors requiring initial response, initial abatement actions or free product removal pursuant to §§ 6203 or 6204), no further site assessment shall be required and the UST system shall be considered permanently closed.

 

(b)Where soil having levels of chemicals of concern below the Tier 1 screening levels for soil quality cannot be reached after excavating 5 feet below the tank bottom, the responsible party shall take at least one ground-water sample to determine whether any Chemicals of Concern in groundwater violate the Tier 1 screening levels.

 

(c)If the owner, operator, another responsible party or remediating party can achieve Tier 1 soil quality standards through the removal of additional soils in the excavation zone; the Tier 1 ground-water standards set forth in section 6210 are not violated; and there is no other visible evidence of contamination (such as free product or vapors requiring initial response, initial abatement actions, or free product removal pursuant to §§ 6203 or 6204), no further site assessment shall be required and the UST system will be considered permanently closed.

 

(d)If after excavation of soils surrounding the UST system the criteria set forth in paragraphs (a), (b) or (c) of this subsection cannot be met, then the owner, operator, another responsible party or a remediating party shall begin corrective action in accordance with the applicable provisions of Chapter 62 as directed by the Director.

 

6101.16Within thirty (30) days after completing the permanent closure or change-in-service activities, the owner, operator, a responsible party or a remediating party shall submit a Closure Assessment Report to the Director in a format provided by the Director, and include a closure notification form.

 

source

Final Rulemaking published at 40 DCR 7835, 7878 (November 12, 1993); as amended by Final Rulemaking published at 46 DCR 7699 (October 1, 1999).