<< Services << Environmental Consulting << Subsurface Remediation Design and Management

Memphis-Shelby County Airport Authority Required UST Removal and Site Remediation of Soils

Issue: The Memphis-Shelby County Airport Authority (MSCAA) acquired the former LTD Air Cargo, Inc., which had a UST system consisting of two 10,000g diesel Underground Storage Tanks (USTs) and one suction type dispenser. Four borings surrounding the UST system were advanced to assess any environmental impacts; elevated contaminant levels were identified in the reserved soil and groundwater samples. The Tennessee Department of Environment and Conservation (TDEC) Division of Underground Storage Tanks (DUST) was notified, and MSCAA decided to permanently close the UST system by removal.

Approach: Once the Initial Abatement Report was approved by TDEC - DUST, UST closure activities began in January 2004. Tank pit soils were not found to contain significant contamination. However, areas surrounding the dispenser were over-excavated to remove petroleum-contaminated soils. Additionally, 63,000 gallons of light petroleum contaminated water was encountered and disposed of. Soil borings/monitoring wells were installed once the tanks and contamination was removed. Semi-annual groundwater monitoring was conducted until groundwater levels were below the DUST approved site specific clean-up levels.

Tasks: Our activities on this assignment included:

Construction Supervision and Management
UST pit sampling
Interpretation of laboratory analysis
Management of contaminated soils
Management of contaminated groundwater
Installation of wells for groundwater monitoring
Followed TDEC clean-up and reporting requirements
Abandonment/closure of wells

Timeline: January 2004 through July 2006

Result: Over 1,800 tons of contaminated soil and 63,000 gallons of contaminated groundwater were removed from around the former USTs. The cessation of the UST system, the removal of fuel from the tanks and the over-excavation of contaminated soils during tank removal actions substantially eliminated the source of contamination and reduced further groundwater contamination. After two years of groundwater monitoring, the wells were abandoned and the site received "no further action" from TDEC.