PNEUMATIC HAMMER SOIL VAPOR PROBES AND MINIATURE PIEZOMETERS FOR GASOLINE SPILL DELINEATION AND CLEANUP

Abstract

ABSTRACT In a new twist on an old procedure, pneumatically injected miniature well points may change soil investigations much as nail guns have changed carpentry. Soil vapor analysis has increasingly gained attention as a means of locating and monitoring subsurface gasoline spills. Accurate depiction of the plume position requires reproducible vapor detection and monitoring. In addition, static water level needs to be determined to understand flow direction. Miniature aluminum slitted well points can be mass-produced by computer-aided production facilities to create low-cost identical copies about 10 cm in length. The small points can be inserted into shafts and injected into the ground. The shaft is then pulled back, leaving a flexible teflon or polypropylene tubing attached. A gasoline spill at Falmouth, Cape Cod, Massachusetts, provided an opportunity to test the use of the injected “shield” points. More than 40 vapor points were installed in two days during four transects across a product plume located 10 m below grade.