Archived
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Location
Lexington, Kentucky
Start Date
7-5-2026 11:30 AM
End Date
7-5-2026 12:00 PM
Description
This session presents a streamlined approach for pump testing of coal combustion residuals (CCR) to maximize hydraulic information with limited well installations, variable pumping rates, and short tests. Pre-test forward modeling identifies well offsets (typically 5–10 ft) and test durations (~2–6 hours) to yield measurable and analyzable drawdown at observation wells despite low pumping rates. Field execution consists of short step-drawdown testing to evaluate well specific capacity and select pumping rates for a constant rate test with one or more observation wells. Test results facilitate analysis of transmissivity and storativity of the CCR. Applied at two Midwestern sites with different CCR material, pumping rates of 0.5 to 7 gpm provide a range of transmissivity and storativity values for both low hydraulic conductivity CCR and high hydraulic conductivity CCR. Observed well drawdown response was consistent with expectations; higher pumping well drawdown (~18–19 ft) for low rates with modest observation well responses at distances of 5–10 ft in low hydraulic conductivity CCR, and minimal drawdown at similar well offsets in high hydraulic conductivity CCR which utilized higher pumping rates. Comparison of pump test results to slug tests and laboratory permeameter results indicate that the hydraulic conductivities are similar to those estimated by slug tests, whereas laboratory results may be an order of magnitude lower, underscoring hydraulic contrast between test methods, and the need to characterize CCR directly. Key lessons include: use of simple forward modeling to identify spacing and duration; leverage 0f specific capacity as a quick field diagnostic; and work within the constraints of existing piezometers. Short, well-designed tests can deliver site specific transmissivity, conductivity, and storativity values for dewatering and closure construction decisions.
Document Type
Presentation
Archival?
Archival
Included in
Energy Systems Commons, Environmental Indicators and Impact Assessment Commons, Environmental Monitoring Commons, Mining Engineering Commons, Oil, Gas, and Energy Commons, Structural Materials Commons, Sustainability Commons
Practical guidelines for pump testing of CCR: workflow, design, and lessons learned.
Lexington, Kentucky
This session presents a streamlined approach for pump testing of coal combustion residuals (CCR) to maximize hydraulic information with limited well installations, variable pumping rates, and short tests. Pre-test forward modeling identifies well offsets (typically 5–10 ft) and test durations (~2–6 hours) to yield measurable and analyzable drawdown at observation wells despite low pumping rates. Field execution consists of short step-drawdown testing to evaluate well specific capacity and select pumping rates for a constant rate test with one or more observation wells. Test results facilitate analysis of transmissivity and storativity of the CCR. Applied at two Midwestern sites with different CCR material, pumping rates of 0.5 to 7 gpm provide a range of transmissivity and storativity values for both low hydraulic conductivity CCR and high hydraulic conductivity CCR. Observed well drawdown response was consistent with expectations; higher pumping well drawdown (~18–19 ft) for low rates with modest observation well responses at distances of 5–10 ft in low hydraulic conductivity CCR, and minimal drawdown at similar well offsets in high hydraulic conductivity CCR which utilized higher pumping rates. Comparison of pump test results to slug tests and laboratory permeameter results indicate that the hydraulic conductivities are similar to those estimated by slug tests, whereas laboratory results may be an order of magnitude lower, underscoring hydraulic contrast between test methods, and the need to characterize CCR directly. Key lessons include: use of simple forward modeling to identify spacing and duration; leverage 0f specific capacity as a quick field diagnostic; and work within the constraints of existing piezometers. Short, well-designed tests can deliver site specific transmissivity, conductivity, and storativity values for dewatering and closure construction decisions.
