Mississippi Administrative Code
Title 11 - Mississippi Department of Environmental Quality
Part 5 - Underground Storage Tank Regulations
Chapter 2 - Mississippi Commission on Environmental Quality Underground Storage Tanks Regulations Technical Standards and Corrective Action Requirements for Owners and Operators of Underground Storage Tanks (UST) (Adopted March 22, 1989; Amended August 25, 2011, Last Amended August 23, 2018)
Appendix 11-5-2-280.4 - GUIDELINES FOR THE PERMANENT CLOSURE OF PETROLEUM UNDERGROUND STORAGE TANK SYSTEMS
Section 11-5-2-280.4-4 - SAMPLING LOCATIONS FOR TANKS
Section 11-5-2-280.4-4.2 - Removal of a Single Tank
Section 11-5-2-280.4-4.2.2 - Removal of a Single Tank - Sidewall Contamination Apparent
If any of the sidewalls appear to be contaminated, sidewall samples must be collected. As shown in Figure 2 below, a minimum of three samples are required to assess the excavation when the sidewalls are contaminated. Two samples must be collected from the sidewalls and one from the floor of the excavation.
The first sidewall sample must be collected from the sidewall of the excavation that appears to be the most contaminated. The second sample must be collected from one of the three remaining sidewalls that appears to have the greatest remaining contamination. If no other sidewall appears to be contaminated, the second sample must be collected from the wall opposite of the sidewall which appears to be the most contaminated. The third sample to be collected must come from the floor of the excavation. The floor sample must be collected from the area of the floor that appears to be the most contaminated. If no area of the floor appears contaminated or if it appears uniformly contaminated the sample must be collected from the center of the excavation.
