Modeling long-term trends of chlorinated ethene contamination at a public supply well

Journal of the American Water Resources Association
By: , and 

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Abstract

A mass-balance solute-transport modeling approach was used to investigate the effects of dense nonaqueous phase liquid (DNAPL) volume, composition, and generation of daughter products on simulated and measured long-term trends of chlorinated ethene (CE) concentrations at a public supply well. The model was built by telescoping a calibrated regional three-dimensional MODFLOW model to the capture zone of a public supply well that has a history of CE contamination. The local model was then used to simulate the interactions between naturally occurring organic carbon that acts as an electron donor, and dissolved oxygen (DO), CEs, ferric iron, and sulfate that act as electron acceptors using the Sequential Electron Acceptor Model in three dimensions (SEAM3D) code. The modeling results indicate that asymmetry between rapidly rising and more gradual falling concentration trends over time suggests a DNAPL rather than a dissolved source of CEs. Peak concentrations of CEs are proportional to the volume and composition of the DNAPL source. The persistence of contamination, which can vary from a few years to centuries, is proportional to DNAPL volume, but is unaffected by DNAPL composition. These results show that monitoring CE concentrations in raw water produced by impacted public supply wells over time can provide useful information concerning the nature of contaminant sources and the likely future persistence of contamination.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Modeling long-term trends of chlorinated ethene contamination at a public supply well
Series title Journal of the American Water Resources Association
DOI 10.1111/jawr.12230
Volume 51
Issue 1
Year Published 2015
Language English
Publisher American Water Resources Association
Publisher location Herndon, VA
Contributing office(s) Toxic Substances Hydrology Program, South Atlantic Water Science Center
Description 13 p.
First page 1
Last page 13
Country United States
State New Jersey
Online Only (Y/N) N
Additional Online Files (Y/N) N
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