Karst Evaluations

Meiser & Earl, Inc. designed and implemented an extensive groundwater tracing study to determine the destination of groundwater that was pumped from a limestone deep mine and disposed in a nearby sinkhole.  A tracer was injected in the disposed water.  Water samples were collected from a network of monitoring points, including private wells, springs, and the deep mine, based on the hydrogeologic setting and suspected groundwater flow directions.  The samples were analyzed to determine actual groundwater flow directions, surface discharge points of the groundwater, and approximate amount of recirculation back into the deep mine.  Recommendations for future water disposal were based on the results of the study.

Meiser & Earl, Inc. evaluated the potential for sinkhole development on properties proposed for residential development, as required by local ordinances.  Meiser & Earl, Inc. reviewed published geologic literature and geologic mapping, as well as large-scale site maps and aerial photographs, to locate potential sinkholes or closed depressions and evaluate the potential for future sinkhole development.  A field inspection was then conducted for evidence of sinkhole development.  Recommendations were made for developing the site and minimizing the potential for sinkhole development.

Walker Township Water Association began work on developing a high-yield water-supply well in a carbonate aquifer.  As part of this project, Meiser & Earl, Inc. evaluated the Target Area with regard to sinkholes as potential pollution sources.  Geologic maps, aerial photographs and a field reconnaissance were utilized to identify sinkholes.  Subsequently, the sinkholes were evaluated with respect to any potential impact to the completed production well.

Meiser & Earl, Inc. conducted literature research and field evaluations of proposed wind turbine foundation locations for potential karst features.  Published geologic maps provided a first approximation of the likely site geology.  Meiser & Earl, Inc. then conducted reconnaissance of each turbine site and the surrounding area, including inspections of bedrock outcrops and float, road cuts, and quarries, to confirm the site geology.  Each proposed foundation site was qualitatively ranked for foundation stability risk and recommendations were made for additional subsurface evaluations, as necessary.

Maidencreek Township Authority wished to develop a 2-million gallon per day ground-water source from a limestone aquifer.  During drilling of the well, sinkholes began to form on an adjacent property.  As part of the hydrogeologic evaluation, the Pennsylvania Department of Environmental Protection (PADEP) requested that Meiser & Earl, Inc. evaluate the relationship of the sinkholes to the well during the pumping test.  Meiser & Earl, Inc. installed a well into the sinkhole and piezometers into the adjacent stream.  These were monitored during the 48-hour pumping test.  In addition, Meiser & Earl, Inc. conducted a bromide tracer test during the 48-hour pumping test to evaluate the relationship between the sinkholes and water pumped from the well and the associated drawdown.