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
Appendix 11-5-2-280.4-H - DEFINITIONS

Aliquot- Part of the whole. One sampling location may require two or more discreet containers in order to qualify as an adequate sample. Each sample container is an aliquot.

Aquifer - Underground bodies of sand or gravel which contains groundwater.

Backfill - All of the soil which was placed in the excavation when the tank system was installed. In UST systems installed after 1988, the backfill is normally easy to determine since tank systems were required to be backfilled with clean sand or gravel and these materials are easily differentiated from the native soil.

BTEX - Benzene, Toluene, Ethylbenzene, and Xylenes, the four major components of gasoline.

Convex Meniscus - Curved or rounded like the outside of a circle.

Decontamination - A process in which to clean and remove contaminants from sample equipment and devices with detergent wash following a series of rinses with distilled water.

Groundwater - For the purposes of UST closures, it is the naturally occurring water that seeps into the tank excavation from the aquifer.

Headspace - The air space between the sample and the top of the closed container.

Holding time - The length of time allowed between sample collection and analysis by the laboratory.

Native soil - Soil which has been undisturbed by activities of man.

PAH - Polynuclear Aromatic Hydrocarbons.

Preservative - A chemical added to a water and/or soil samples to prevent deterioration or to maintain the original characteristics.

Repair - To restore a piping system. Repair as utilized in this document means that some minor component, such as a flex connector or a coupling/union, of the piping system has been replaced or simply tightened.

Septum cap - A sample container cap that has a membrane for extracting water with a syringe.

Stockpiling - Storing excavated materials on site. Correct stockpiling requires putting the excavated material on plastic at a height not greater than 3 feet. A berm should surround the stockpiled material in order to prevent rainwater run-off.

Teflon lined - A synthetic liner used to line the sides and caps of sample containers to prevent samples from sticking.

VOC - Volatile Organic Compounds - chemicals which readily vaporize under normal atmospheric conditions.