Publication Summary

This report presents an evaluation of Cardenas and Zlotnik′s piezometer-based, constant head injection test (CHIT) for estimating the hydraulic conductivity (K) of streambed and lake-bed sediments during studies of groundwater/surface water exchange. In addition to assessing the practical application of the test, a sensitivity analysis was completed to determine the influence of field measurement errors on the K estimate.

The simplicity and speed of the test procedure can improve efforts to bracket the K variability of groundwater/surface water interface-zone sediments throughout a study area. Standardized operating procedures and recommendations are presented for future use of the CHIT method.

August 2007 update: The original version of this publication (November 2006) has been updated to reflect an erratum published for the Cardenas and Zlotnik (2003) reference. Several mathematical terms were also revised to provide consistency with that erratum.

This paper presents an evaluation of Cardenas and Zlotnik′s piezometer-based, constant head injection test (CHIT) for estimating the hydraulic conductivity (K) of streambed and lake-bed sediments during studies of groundwater/surface water exchange.

To provide experimental data for this evaluation, the CHIT was performed on 21 small-diameter, instream piezometers deployed in support of ongoing Washington State Department of Ecology (Ecology) Total Maximum Daily Load (water cleanup plan) studies. In addition to assessing the practical application of the test for future Ecology studies, a sensitivity analysis was completed to determine the influence of field measurement errors on the K estimate.

The simplicity and speed of the test procedure can improve efforts to bracket the K variability of groundwater/surface water interface-zone sediments throughout a study area.

Standardized operating procedures and recommendations are presented for future use of the CHIT in Ecology studies.