SYMPOSIA PAPER Published: 01 January 1992
STP19135S

A Field Investigation of Ground-Water Monitoring Well Purging Techniques

Source

A field investigation of commonly-used monitoring well purging techniques was conducted under different conditions including type of pump, pump inlet location, and the use of packers. Tracers including deionized water, fluorescent dye, and lithium chloride, were used to define the amount of stagnant water at any given time in the pump discharge. Tests were conducted in shallow 5 cm (2 in) diameter wells. The effects of drawdown were examined.

Tests conducted in the absence of drawdown with the pump inlet in a fixed position at or above the screen showed a highly variable and unpredictable inclusion of stagnant water. The use of packers did not completely prevent the inclusion of stagnant water into the pump inlet. The inclusion of stagnant water into a sample was minimized by purging from some distance above the screen followed by relocation of the pump inlet into the screen for sample collection. In wells where drawdown occurred during purging, stagnant water inclusion was minimized by reduced pumping rates to allow for sample collection during periods of well recharge. Real time monitoring of indicator parameters such as pH, temperature and specific conductance was not generally successful in indicating when purging was complete.

Author Information

Maltby, V
National Council of the Paper Industry for Air and Stream Improvement, Inc., Central-Lake States Regional Center, (NCASI), Western Michigan University, Kalamazoo, MI
Unwin, JP
National Council of the Paper Industry for Air and Stream Improvement, Inc., Central-Lake States Regional Center, (NCASI), Western Michigan University, Kalamazoo, MI
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Details
Developed by Committee: D18
Pages: 281–299
DOI: 10.1520/STP19135S
ISBN-EB: 978-0-8031-5182-6
ISBN-13: 978-0-8031-1462-3