By Hydrosimulatics INC  

Dry cleaner establishments are quite common in urban settings. And so is the contamination that is associated with dry cleaning activities. Such contamination may pose serious health risks due to its nature and resistance to environmental degradation.

Use MAGNET to simulate the migration of two TCE contamination plumes at a Houston dry cleaner site in Texas. The TCE contamiantion has impacted a local neighborhood. 

Two dry cleaner facilities were located in the contaminated area at the Houston site (3500ft x 3500 ft, see figure below). The first operated from the mid 1970s until 1996, while the second opened in 1993 and is still in operation. Beneath the surficial clay in Houston, the affected aquifer is silty/sandy with a hydraulic conductivity of 5 x 10-3 cm/s. The aquifer is unconfined with water table at about 20 ft below groundwater surface, and a clay layer approximately 30-35 ft BGS. The gradient of the groundwater is approximately in a generally southward direction. A stream north/northeast of the facilities provides shallow groundwater recharge in the region. For this exercise, the facilities is assumed to be a continuous source of contamination, with a constant concentration of approximately 100 ppb.

MAGNET/Modeling Hints: 

  • Use 'Synthetic Mode' to set up your flow model ( 'Other Tools' > 'Utilities' > 'Go to Synthetic Case Area')
  • Use the ‘Distance Display’ capabilities when editing geometric features and/or the ‘Ruler’ tool to properly represent distances between model features.
  • Represent the streams as constant head line features.