Monitoring DNAPL pumping using integrated geophysical techniques

Technical Report · Wed Jan 01 04:00:00 EST 1997

DOI:https://doi.org/10.2172/493339· OSTI ID:493339

Newmark, R L

The removal of DNAPL during pumping was monitored. At Hill AFB in Utah, a free-product DNAPL plume (predominantly TCE, with some TCA, PCE, methylene chloride) is pooled in water-wet soil on a thick clay aquitard. Groundwater pumping at Operable Unit 2 began in 1994; to date, nearly 30,000 gal DNAPL have been recovered. From Sept. 1994 through Sept. 1995, changes in the basin during DNAPL pumping were monitored using fiber optic chemical sensors, neutron logs, and electrical resistance tomography (ERT). The first two sensor types verify the presence of DNAPL in vicinity of 3 boreholes which form a cross section from the perimeter of the basin to its center. Cross borehole ERT images the changes in formation electrical properties due to removal of DNAPL, extending the understanding of DNAPL removal between the boreholes. During pumping, electrical resistivities decreased; we suggest these decreases are directly caused by the reduction in DNAPL. During ground water pumping, water with relatively low resistivity replaces some of the DNAPL pockets as the highly insulating DNAPL is removed. Results suggest that, as DNAPL is pumped from a nearby well, product slowly drains along the top of an aquitard and into the pump well, where it collects.

• Research Organization: Lawrence Livermore National Lab., CA (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 493339
• Report Number(s): UCRL-ID--122215; ON: DE97052574
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
AQUIFERS
BOREHOLES
LAND POLLUTION
MILITARY FACILITIES
MONITORING
ORGANIC COMPOUNDS
ORGANIC SOLVENTS
PUMPING
REMEDIAL ACTION
UTAH