Answer Happy

Introduction: In the early- to mid-eighties, residence of Woburn Massachusetts experienced a cluster of Leukemia diagnoses, which were thought to be a result of contaminated groundwater that was used for drinking purposes. As a result, a lawsuit was filed, in 1986, against Beatrice Foods [C], a tannery; W.R. Grace, a manufacturing plant [A]; and UniFirst , a laundry service. These companies were thought to have mishandled chemicals (TCE and PCE) that ultimately discharged to groundwater in the area and migrated to water production wells (G and H). This case became the basis of an award winning book and movie starring John Travolta, called A Civil Action (1998). The main goal of this laboratory is do assess who, if anyone, is responsible for the TCE plume.

Print from the Well_Head_Maps.xls file a) Pre-1967 conditions map, before wells G and H were installed and pumped b) 1967-1979 conditions, after wells G and H were installed. Questions: 1) Where is the hydraulic gradient steepest? And, where is it flat? What implication does this have for groundwater flow and contaminant migration? Explain. 2) Throughout both maps, draw several flow lines with arrows pointing in the direction of flow starting at points [A], [B), and [C] (remember that flow lines are at 90 degrees to potentiometric contours). What is the overall direction of flow from each of the starting points and for both maps?

POTENTIOMETRIC SURFACE January 3, 1986 - Wells G and H Pumping 1967 to 1979 Conditions X 46.2 В Olympia Avenue 4,000 58.0 Washington Street X Well Hw Well G C 2,000 Salem Street Riley Well Aberjona River 0 2,000 4,000

EXPLANATION Pumping well A = W.R. Grace - Cryovac Plant Monitoring well B = UniFirst Streambed piezometer C = Riley Tannery property Contours Interval = 2 ft N Х