Analysis of Ground Water Drawdowns using Field Monitoring, Computer Modeling and Theoretical Techniques at Monroe Marketplace, Hummels Wharf, PA

Abstract

A newly built shopping center called Monroe Marketplace Plaza, located in Hummels Wharf, Pennsylvania, raised concern among local residents after they heard about the high rate of two pumping wells placed in the vicinity of their homes. The study herein was conducted by monitoring 4 domestic wells from March 2008 through January 2010, theoretically by using Neuman and Witherspoon equation, and lastly by groundwater modeling. The results showed that both Neuman and Witherspoon equation and groundwater modeling results are in agreement with the observed data when a hydraulic conductivity of 9.26x10−7 ft/sec (2.78x10−7 m/sec) was used. The results indicate that the initial drawdown of 19 ft (6 m) observed during the monitoring period in well 4 was caused by a nearby well that was pumping at high rate. The location of both pumping wells has arrested the cone of depression to the center of the plaza without major effect on the well 1, 2, and 3. The groundwater level gradually increased due to high specific yield of the aquifer and has since readjusted to new hydrological condition, fluctuating only to recharge effects. Overall, all 3 methods approximate similar results or complement each other and for a practical approach makes it highly unlikely that the New Marketplace's water consumption will affect residential water supply.