Induced Infiltration and the Aberjona River
Module Goal:
- Understand the difficulties associated with measuring river infiltration into groundwater.
- Learn how groundwater pumping can create increases in surface water discharge to the aquifer.
- Review how the experts dealt with attempts to quantify discharge from the Aberjona River and project the resulting effects to water quality.
Overview
A significant stumble by the plaintiffs expert hydrogeologist, Dr. George Pinder, was related to the assessment of water contribution to the aquifer from the Aberjona River and accounting for the amount of river water captured by the pumping of Wells G & H. Excerpts of the testimony (see copies) clearly show the importance of this aspect of assessing hydrogeologic conditions of the Aberjona River Valley. The ambiguity presented in Dr. Pinder's testimony was identified by several jurors as their reason for skepticism of being able to conclusively identify the source and contribution of contaminants to the wells.
Understanding the effect of induced infiltration to aquifers.
Understanding how induced infiltration has to be considered as part of the value waiting either geologic budgets is an important aspect of understanding the sustainability of the resource. This topic is addressed in the USGS Circular 1186. Pages 30 through 35 illustrate how contributions of streamflow can be toward or away from water table depending on seasonal conditions and induce drawdown from pumping, as described in the section on groundwater budgets.Profile of the Aberjona River Valley
The geologic data presented in Module 3, which is taken directly from court records can be used to construct a cross-section of the Aberjona River River Valley. One of the considerations in creating a cross-sectional profile that this data is defining the effects of peatthat underlie the river, and it tills that underlie the Cryovac site. In preparing for a mock trial, a critical question which needs to be addressed is the effect of these materials on induced infiltration from the river to the Wells.
Student Assignment