G P Wealthall, S F Thornton and D N Lerner
Groundwater Protection and Restoration Group,
University of Sheffield, UK
www.sheffield.ac.uk/gprg
Source Term
Approximately 55,000 L of unleaded fuel was accidentally released from an underground storage tank in February 1999:
- The spilled fuel contains the ether oxygenates methyl tertiary-butyl ether (MTBE) and tertiary methyl-amyl ether (TAME), at concentrations of 2.88 and 1.65% v/v., respectively
- Theoretical calculations suggest that LNAPL has penetrated along vertical fractures to at least 16 m below the rest water table. This explains the observed migration of dissolved contaminants to a depth of 40 m below forecourt level (mbfl) within 30 m distance downgradient of the site, in the absence of a significant vertical hydraulic gradient