Module 5: Groundwater Flow to Wells G & H

Module Goals

• Provide students with an overview of the interaction between groundwater pumping and the recharge from surface water bodies.
• Investigate the conflicting arguments made by experts regarding the role of water discharged from the Aberjona River to the aquifer.

Student Assignment

Introduction

One of the most important questions raised during the Woburn trial focused on where water pumped from Wells G & H originated. The disagreements between the plaintiffs in the defendants regarding the contribution of water from the Aberjona River, the glacial sentiments in the northeastern portion of the drainage area near the Grace Cryovac facility, and the influence of the Riley pumping well created some of the controversy and dispute during testimony.

Understanding the interaction between surface water and groundwater

Much of the dispute that occurred during the Woburn trial centered on contributions of water from the Aberjona River and other parts of the aquifer. USGS circular 1139 provides an excellent overview of the relationship between surface water, groundwater and the sustainable use of groundwater.

Evaluating sources of impacts to Wells G & H

To make arguments regarding the potential sources of TCE, the plaintiffs' expert had to define the subsurface geology, the hydrology of the area, and assemble evidence indicating that TCE was used at both the Riley / Beatrice and W.R. Grace properties. Counsel for the plaintiffs was able to identify Grace employee's who were involved with on-site TCE disposal activities. However, the plaintiffs' council were not able to directly link disposal of wastes on the Riley 15-acre property with activities at the tannery itself. Keep in mind that Judge Skinner separated the trial into three phases (more information) and proving the connection between the contaminants migrating to Wells G and H during the first phase of the trial required to proceed to the remaining two trial phases. The ATSDR report, which was prepared three years after the trial, is a good illustration of how difficult it is to conclusively assess risk from a specific source at the Woburn site.

Student Assignment

More information

Sustainability of ground-water resources|Computing stream loss by wells