Just as performing an angiogram allows physicians to understand any problems with blood flow prior to surgery, performing a Willowstick survey allows for improved understanding of groundwater connections before remediation. Both allow for more targeted methods to be employed. Reduce exploration and remediation costs and rest assured that you have an accurate characterization of your groundwater. In the image below the yellow lines represent preferential groundwater flow paths identified after a Willowstick Survey was completed. Imagine being an owner not knowing where to drill to identify groundwater problems to having specific targets with coordinates and knowing exactly where to drill.
2D Maps
The initial maps that are provided to our clients are 2D. These maps allow us to rapidly communicate with the client on survey results within the first day or two of starting fieldwork. This allows for collaboration on how the fieldwork should progress based on active observations. Our clients see initial results on every survey we perform before we leave the site. This puts the client in control of the investigation and avoids any surprises.
The above 2-D map shows preliminary interpretation of subsurface water seepage pathways (yellow lines) of dam seepage.
3D Models
Understanding subsurface water connections is critical to enhancing site conceptual models so that better decisions can be made regarding the monitoring and remediation of a particular site. Willowstick employs two different modeling techniques when producing 3D groundwater models. They are Electric Current Flow Models and Electric Current Distribution Models. They are explained in more detail below.
Electric Current Flow Models (ECF)
With the same magnetic field data used to generate the 2D maps, an electrical current is simulated in a modeling environment and a theoretical magnetic field contour map is created. Next, the modeler adjusts the depth and electrical current flow until he can match the theoretical magnetic field contours with the observed magnetic field contours. Once a reasonable match is achieved, the modeler can assign depths to the individual pathways.
The ECF model above depicts two seepage pathways (blue lines) and how they move through the dam or under an existing grout wall.
Electric Current Distribution Model (ECD)
The ECD model above shows the distribution of electrical current and how meteoric water was infiltrating into a deep aquifer.
These models depict the distribution of electrical current through a given site. The data is subjected to an inversion algorithm (mathematical model) designed to identify the distribution of 3D electric current flow within the study area. This modeling process provides clients detailed views of how seepage paths are connected through their site. This model is then provided to the clients for incorporation into their own site models.
