Monday, March 31, 2008 : 2:00 p.m.

An Exploration of Dual Phase Extraction Pilot Testing Methodologies, Data Analysis, and Interpretation, including Implications for Radius of Influence Calculations

Ethan O. Weikel, PG and Brian P. Shedd, Kleinfelder Inc.

Dual Phase Extraction (DPE) is a remedial technique that involves the extraction of soil vapor, ground water, and liquid phase hydrocarbon (if present) simultaneously through the use of a high-vacuum pump or blower system.  This technique is intended to maximize extraction rates of both vapor and liquids but is dependent upon a wide range of parameters and the sensitivity of those parameters.

 Data from several events was analyzed to explore the influences of vapor extraction on measured water levels during dual phase extraction pilot testing.  Data from the events typically consists of fluids recovery and rates, and groundwater elevations based on pressure transducer and manual measurement data.  Variable influences were observed dependent upon the methodology used for monitoring vacuum and groundwater levels.  The data is collected through a variety of means including methodologies as simple as measurement using capsuhelic gauges and interface probes to data logging pressure transducers.

 To better understand the relationship between observed values and actual values small scale models and theoretical proxies were constructed.  Various pressures, extraction rates, and modeled aquifer materials were tested, and measurements and visual observations were used to evaluate the effects of the testing.

Ethan O. Weikel, PG, Kleinfelder Inc. Mr. Weikel received a B.S. in Structural Geology from the College of William and Mary in Virginia. At William and Mary, his focus was also on sedimentology and stratigraphy, and included field mapping for the U.S. Geological Survey in the Virginia Piedmont Province. Mr. Weikel continued his work in northern California with an emphasis on hydrogeology and water resources. Mr. Weikel is a Professional Geologist with licensure in CA, DE, PA, and VA and is currently working in the Mid-Atlantic as a Project Manager and Hydrogeologist, focusing on hydrogeologic assessment and water resources management.

Brian P. Shedd, Kleinfelder Inc. Mr. Shedd received a B.S. degree in geology with a focus in water resources from the State University of New York College at Oneonta. Mr. Shedd is currently employed by Kleinfelder, working as a hydrogeologist on complex, small-scale, hydrogeologic investigations and contaminant assessment and remediation in Maryland, Virginia, Delaware, and Washington DC.


2008 Ground Water Summit