The Purge Analyzer Tool (PAT) to Assess Optimal Pumping Parameters in the Collection of Representative Groundwater Samples from Wells
The U.S. Geological Survey (USGS), in cooperation with the U.S. Environmental Protection Agency, has developed an analytical model to assess in-well groundwater flow conditions during the collection of groundwater samples from monitoring wells. The Purge Analyzer Tool (PAT) can be used by professionals conducting groundwater sampling to compute parameters that can inform when and how to collect samples that best characterize the targeted aquifer or hydrogeologic unit.
The U.S. Geological Survey (USGS), in cooperation with the U.S. Environmental Protection Agency, has developed an analytical model to assess in-well groundwater flow conditions during the collection of groundwater samples from monitoring wells. The Purge Analyzer Tool (PAT) can be used by professionals conducting groundwater sampling to compute parameters that can inform when and how to collect samples that best characterize the targeted aquifer or hydrogeologic unit.
A primary goal of low-flow sampling of groundwater (pumping at low rates [0.1–0.5 L/min]) is to minimize the amount of water pumped from in-well storage by avoiding drawdown in the well. However, low-flow sampling does not minimize the capture of preexisting water in the screened interval (called screen storage) or mixing of water from screen storage with recent inflow of formation water induced from pumping. The PAT can help with characterizing and describing in-well flowpaths and assessing how the differences within and between rock and sediment layers affect the ability to collect representative groundwater samples.
The PAT code is available as a VBA script embedded in a macro-enabled Microsoft Excel spreadsheet. Field data have been collected to help assess the capability of the PAT to simulate in-well groundwater flow. This effort included the collection of travel time data (via tracer methods) that was compared to simulated travel times in the PAT. Test data were collected at the Stringfellow Superfund Site in California. The PAT has been applied at sites in New England, North Carolina, and Texas.
Collaborations with EPA on Contaminated Site Hydrology
Augmented Site Characterization of PFAS Manufacturing and Processing Facilities
Detailed Characterization of the Savage Superfund Site, New Hampshire
The Aqueous Flow Concentration Estimator (AFCE): Software for Estimation of Ambient Groundwater Flow in Bedrock Open Boreholes
The U.S. Geological Survey (USGS), in cooperation with the U.S. Environmental Protection Agency, has developed an analytical model to assess in-well groundwater flow conditions during the collection of groundwater samples from monitoring wells. The Purge Analyzer Tool (PAT) can be used by professionals conducting groundwater sampling to compute parameters that can inform when and how to collect samples that best characterize the targeted aquifer or hydrogeologic unit.
The U.S. Geological Survey (USGS), in cooperation with the U.S. Environmental Protection Agency, has developed an analytical model to assess in-well groundwater flow conditions during the collection of groundwater samples from monitoring wells. The Purge Analyzer Tool (PAT) can be used by professionals conducting groundwater sampling to compute parameters that can inform when and how to collect samples that best characterize the targeted aquifer or hydrogeologic unit.
A primary goal of low-flow sampling of groundwater (pumping at low rates [0.1–0.5 L/min]) is to minimize the amount of water pumped from in-well storage by avoiding drawdown in the well. However, low-flow sampling does not minimize the capture of preexisting water in the screened interval (called screen storage) or mixing of water from screen storage with recent inflow of formation water induced from pumping. The PAT can help with characterizing and describing in-well flowpaths and assessing how the differences within and between rock and sediment layers affect the ability to collect representative groundwater samples.
The PAT code is available as a VBA script embedded in a macro-enabled Microsoft Excel spreadsheet. Field data have been collected to help assess the capability of the PAT to simulate in-well groundwater flow. This effort included the collection of travel time data (via tracer methods) that was compared to simulated travel times in the PAT. Test data were collected at the Stringfellow Superfund Site in California. The PAT has been applied at sites in New England, North Carolina, and Texas.