Hydraulic testing of a single screened well to implement a multi-level purge and sampling design

Conference · Wed Oct 01 04:00:00 EDT 1997

OSTI ID:526130

Caplan, K S; Peck, T J; MacFarlane, I D; Lige, J E ^[1]

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1. EA Engineering, Science, and Technology, Inc., Sparks, MD (United States)

Vertical flowmeter testing of a fully penetrating well, screened in a confined sand and gravel aquifer, was performed to characterize the vertical variation of aquifer hydraulic conductivity. Acquired data were used to design multi-level sampling without the use of packers or nested wells. While slow pumping the well from above the screened interval, a Mount Sopris Instrument Company, Inc. Heat Pulse vertical flowmeter was used to log the cumulative contribution to vertical flow in the well at 1-ft intervals. An impeller flowmeter was also tested at higher purge rates, but could not measure low flows near the bottom of the well. An equation derived was applied to the data to solve for hydraulic conductivity at each interval using an average hydraulic conductivity calculated from slug tests. Variations of hydraulic conductivity correlated closely with sedimentary strata. Changes in the rate of cumulative flow versus depth were used to select discrete well sampling intervals for simultaneous, multi-level sampling of the well without causing in-well mixing. Peristaltic pumps and stainless steel tubing were used. Ground-water samples were analyzed for organic compounds to evaluate if contaminant concentrations resulted either from the dissolution of a bottom dense non-aqueous phase liquid (DNAPL) layer or preferential flow of contaminants from a distal DNAPL source through coarser sediment layers.

• OSTI ID: 526130
• Report Number(s): CONF-970344--
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
58 GEOSCIENCES
AQUIFERS
ECOLOGICAL CONCENTRATION
ENVIRONMENTAL TRANSPORT
FIELD TESTS
FLOWMETERS
GROUND WATER
HYDRAULIC CONDUCTIVITY
ORGANIC COMPOUNDS
REMEDIAL ACTION
SAMPLING