Index to Western Geo-Engineers WEB Site, Western Geo_Engineers provides a board array of enviromental geologic services:

Determination of Groundwater Hydraulic Parameters

The groundwater and aquifer parameters of most importance are:

Gradient, the change in elevation of water over distance;

(K), the hydraulic conductivity;

n, the porosity;

ne, the effective porosity;

S, the aquifer storetivity;

Aquifer thickness;

Aquifer lithology;

Aquifer carbon content.

Of these parameters, aquifer thickness and lithology can be determined while drilling the well, or from "through the casing" radiation/electric logging of completed or installed wells. Reasonably, accurate estimations of n, ne and the carbon content can be determined from laboratory analysis of samples collected during drilling. The gradient can be calculated from the groundwater elevations in a minimum of three wells. In order to determine the remaining parameters some type of aquifer testing must be done. The type and duration of the aquifer test used is dependent on the data needed.

Two types of aquifer tests are routinely performed at contaminated sites: slug/bail tests and pump tests:

Slug/Bail Test

The Groundwater parameter K, the hydraulic conductivity is determined by this test. We often use the Slug/Bail Test during Rapid Site Characterization. The K value and parameters collected during installation of the wells will allow a Tier 2 evaluation of the site.

Pump test

Groundwater parameters determined by the pump tests are:

K, the hydraulic conductivity.
S, the aquifer storativity.
T, Aquifer transmissivity.

If it is determined that the site hydrogeology is complex enough, the data collected during the pump test can be used to help develop a numeric model of the site