Recharge Study
DEQ
has funded a recharge study since 1999.
WDEQ continues recharge study to assist Army Corps in
understanding the hydrology of the site in order to better plan clean-up
of the TCE groundwater contamination.
WDEQ staff collect monthly water level data from the aquifer.
Staff used this data to model recharge for the Missile Site and
the Belvoir Ranch.
Summary
Groundwater recharge is an incredibly important parameter for the
Belvoir Ranch.
Understanding and being able to predict recharge and its mechanisms
serves many purposes. These
purposes include: long-term aquifer response, contaminant transport,
plume dynamics, and modeling of remediation strategies.
Since the fall of 2007, WDEQ staff have been regularly collecting water
levels from approximately 40 USACE monitoring wells and 8 City of
Cheyenne test wells.
Regularly collected water level data reveal groundwater recharge trends
and quantities. The data
have been used for general observation, as well as calibration data for
a model to simulate groundwater recharge based on precipitation.
The model used to simulate current and future groundwater recharge is
called SWAT or the Soil and Water Assessment Tool.
This is a GIS based mass balance model for both surface and
subsurface water. By using
Belvoir characteristics of topography, land use, soil, weather data, and
groundwater levels the model was made to predict groundwater recharge
based on annual precipitation.
The following relationship was made with the model:
Groundwater recharge can be reasonably estimated by using this relationship.
Update on Latest Results
Groundwater levels are collected on a monthly basis. WDEQ hopes to continue this effort until the data spans at least five years. The results for the 2009 through 2010 hydrologic year (October through September) have shown higher rates of recharge than any time before in the study. These results have only been qualitatively studied. In the future, these results will be updated with the model to obtain a more accurate model for groundwater recharge.