The Purge Analyzer Tool (PAT) to Assess Optimal Pumping Parameters in the Collection of Representative Groundwater Samples from Wells Active
The U.S. Geological Survey in cooperation with the U.S. Environmental Protection Agency is developing analytical models to assess in-well groundwater flow conditions during the collection of groundwater samples from wells being pumped. This information can be used to inform groundwater samplers on when and how to collect samples that are most reflective of the targeted aquifer or hydrogeologiic unit.
Methods: In addition to the development of an easy to use analytical VBA code embedded into a spreadsheet file, field data has been collected to help asses the capability of the PAT to simulate in-well groundwater flow. The field data includes the collection of well tracer data to confirm observed travel times in wells that can be compared to simulated travel times in the PAT.
Below are data or web applications associated with this project.
Data associated with the evaluation of the PAT (Purge Analyzer Tool), Stringfellow Superfund site, Jurupa Valley, California, 2017
The concepts behind the PAT analytical program are discussed in the papers.
These papers include a discussion on the rationale for determination of in-well groundwater flow and time of travel, and on the limitations inherent in the program, which is important to ensure proper use.
Evaluation and application of the Purge Analyzer Tool (PAT) to determine in-well flow and purge criteria for sampling monitoring wells at the Stringfellow Superfund site in Jurupa Valley, California, in 2017
Borehole‐scale testing of matrix diffusion for contaminated‐rock aquifers
Instructions for running the analytical code PAT (Purge Analyzer Tool) for computation of in-well time of travel of groundwater under pumping conditions
In-well time-of-travel approach to evaluate optimal purge duration during low-flow sampling of monitoring wells
Hydraulically controlled discrete sampling from open boreholes
Below are software products associated with this project.
Software for the analytical code PAT (Purge Analyzer Tool) for computation of in-well time of travel of groundwater under pumping conditions
Purge Analyzer Tool - For computation of in-well time of travel of groundwater under pumping conditions.
Below are partners associated with this project.
- Overview
The U.S. Geological Survey in cooperation with the U.S. Environmental Protection Agency is developing analytical models to assess in-well groundwater flow conditions during the collection of groundwater samples from wells being pumped. This information can be used to inform groundwater samplers on when and how to collect samples that are most reflective of the targeted aquifer or hydrogeologiic unit.
Methods: In addition to the development of an easy to use analytical VBA code embedded into a spreadsheet file, field data has been collected to help asses the capability of the PAT to simulate in-well groundwater flow. The field data includes the collection of well tracer data to confirm observed travel times in wells that can be compared to simulated travel times in the PAT.
- Data
Below are data or web applications associated with this project.
Data associated with the evaluation of the PAT (Purge Analyzer Tool), Stringfellow Superfund site, Jurupa Valley, California, 2017
Data presented here were collected in support of analyzing the analytical model PAT (Purge Analyzer Tool). There are manual measurements of well construction, hydraulic, and chemical data for several wells from the Stringfellow Superfund site, Jurupa Valley, California. The hydraulic data includes hydraulic head. Chemical data includes physiocochemical data. Physiocochemical profiles of the well w - Publications
The concepts behind the PAT analytical program are discussed in the papers.
These papers include a discussion on the rationale for determination of in-well groundwater flow and time of travel, and on the limitations inherent in the program, which is important to ensure proper use.
Evaluation and application of the Purge Analyzer Tool (PAT) to determine in-well flow and purge criteria for sampling monitoring wells at the Stringfellow Superfund site in Jurupa Valley, California, in 2017
The U.S. Geological Survey and U.S. Environmental Protection Agency are developing analytical tools to assess the representativeness of groundwater samples from fractured-rock aquifers. As part of this effort, monitoring wells from the Stringfellow Superfund site in Jurupa Valley in Riverside County, California, approximately 50 miles east of Los Angeles, were field tested to collect information tAuthorsPhilip T. Harte, Tomas Perina, Kent Becher, Herb Levine, Daewon Rojas-Mickelson, Lesley Walther, Anthony A. BrownBorehole‐scale testing of matrix diffusion for contaminated‐rock aquifers
A new method was developed to assess the effect of matrix diffusion on contaminant transport and remediation of groundwater in fractured rock. This method utilizes monitoring wells constructed of open boreholes in fractured rock to conduct backward diffusion experiments on chlorinated volatile organic compounds (CVOCs) in groundwater. The experiments are performed on relatively unfractured zones (AuthorsPhilip Harte, William C. BrandonInstructions for running the analytical code PAT (Purge Analyzer Tool) for computation of in-well time of travel of groundwater under pumping conditions
IntroductionUnderstanding the optimal time needed to purge a well while pumping to collect a representative groundwater sample requires an understanding of groundwater flow in wells (in-well flow). Parameters that affect in-well flow include the hydraulic properties of the aquifer, well construction, drawdown from pumping, and pump rate. The time of travel relative to in-well flow is affected by tAuthorsP.T. Harte, B. J. Huffman, Tomas Perina, Herb Levine, Daewon Rojas-MickelsonIn-well time-of-travel approach to evaluate optimal purge duration during low-flow sampling of monitoring wells
A common assumption with groundwater sampling is that low (<0.5 L/min) pumping rates during well purging and sampling captures primarily lateral flow from the formation through the well-screened interval at a depth coincident with the pump intake. However, if the intake is adjacent to a low hydraulic conductivity part of the screened formation, this scenario will induce vertical groundwater flow tAuthorsPhilip T. HarteHydraulically controlled discrete sampling from open boreholes
Groundwater sampling from open boreholes in fractured-rock aquifers is particularly challenging because of mixing and dilution of fluid within the borehole from multiple fractures. This note presents an alternative to traditional sampling in open boreholes with packer assemblies. The alternative system called ZONFLO (zonal flow) is based on hydraulic control of borehole flow conditions. Fluid fromAuthorsPhilip T. Harte - Software
Below are software products associated with this project.
Software for the analytical code PAT (Purge Analyzer Tool) for computation of in-well time of travel of groundwater under pumping conditions
Purge Analyzer Tool - For computation of in-well time of travel of groundwater under pumping conditions.
- Partners
Below are partners associated with this project.