# Springer and Gelhar Slug Test Solution for Unconfined Aquifers

Related Solution Methods

Additional Topics

A mathematical solution by Springer and Gelhar (1991) is used to determine the hydraulic conductivity of **unconfined** aquifers. The method accounts for inertial effects in the well and oscillatory slug test response in a high-hydraulic conductivity (high-K) aquifer. Analysis involves matching a type-curve solution to water-level displacement data collected during an underdamped slug test. The Springer and Gelhar solution also incorporates frictional well loss in small-diameter wells (Butler 2002).

AQTESOLV provides visual and automatic methods for matching the Springer and Gelhar solution to slug test data. This easy-to-use and intuitive software promotes rapid and accurate determination of aquifer properties.

## Assumptions

The following assumptions apply to the use of the Springer and Gelhar slug test solution:

- aquifer has infinite areal extent
- aquifer is homogeneous and of uniform thickness
- aquifer potentiometric surface is initially horizontal
- control well is fully or partially penetrating
- a volume of water, V, is injected or discharged instantaneously from the control well
- aquifer is unconfined
- flow is steady

## Solution

Options

AQTESOLV provides the following options for the Springer and Gelhar slug test solution:

- partially penetrating wells
- correction for gravel pack porosity
- correction for frictional well loss
- hydraulic conductivity anisotropy

## Benchmark

## References

Springer, R.K. and L.W. Gelhar, 1991. Characterization of large-scale aquifer heterogeneity in glacial outwash by analysis of slug tests with oscillatory response, Cape Cod, Massachusetts, U.S. Geol. Surv. Water Res. Invest. Rep. 91-4034, pp. 36-40. [pdf]