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 11-5-2-280.4-5 - SAMPLING LOCATIONS FOR DISPENSER ISLANDS & PIPING
Section 11-5-2-280.4-5.2 - Dispenser Islands
Section 11-5-2-280.4-5.2.2 - Removal of Dispenser Islands - Sidewall Contamination Apparent
If any of the sidewalls of the excavation appear to be contaminated, the sidewalls must be sampled. At least two samples are required for dispenser islands less than 50 feet in length when sidewall sampling is necessary. One sample must be collected from the area of the sidewall that appears to be the most contaminated. The second sample must be collected from the floor of the excavation where the most contamination appears to be present. The second sample must be collected from the floor of the piping trench and at least one foot into the native soil. If no area of the floor appears contaminated or it appears uniformly contaminated, the sample must be collected as shown in Figure 8.
If the dispenser island is greater than 50 feet in length and sidewall sampling is necessary, at least three samples are required. One of the samples must be collected from the area of the sidewall that appears to be the most contaminated. The other two samples must be collected from the floor of the excavation where the most contamination appears to be present. However, you should also take into consideration the entire area of the excavation so that both of the floor samples are not collected from the same general area. If no area of the floor appears contaminated or if it appears uniformly contaminated, collected floor samples as shown in Figure 8.
