An underground storage tank (UST) and associated piping is used to store hazardous and non-hazardous substances such as petroleum at fuel stations and solvents at dry cleaning facilities. Releases from USTs can result in soil and groundwater contamination with LNAPL and DNALP and subsequent vapor intrusion into aboveground structures.

LNAPL-Update (LNAPL-3)
Section 3 (Key LNAPL Concepts)
Provides fundamental LNAPL concepts to understanding the logic used in the development of the tools and key to appropriate application of this guidance. 

Remediation Process Optimization (RPO-2)
Example 2 (UST Case Study), pages 8-12
Uses a case example of a UST release to discuss cost savings from additional remedial action.

Vapor Intrusion (PVI-1)
Appendix E (Common Types of Petroleum Sites, Gasoline and Diesel USTs)
This appendix summarizes different features that may influence the potential for petroleum vapor intrusion (PVI).