Post-closure Responses in Groundwater Quality.pdf

Chris Lalonde, Stantec
Jim Finley, Stantec
Paul Thomas, Tennessee Valley Authority

Description

Post-closure - Responses in Groundwater Quality and Chemistry Authors Mr. Chris Lalonde - United States - Stantec Mr. Jim Finley - United States - Stantec Mr. Paul Thomas - United States - Tennessee Valley Authority Abstract Is there a meaningful and measurable improvement in groundwater quality following closure in place of a coal combustion residuals (CCR) unit by installation of a geosynthetic cover system? Using data collected at a closed CCR unit, we examined the response of pore water levels within the CCR material and groundwater quality along the downgradient edge of the CCR unit following closure in place that included capping to prevent infiltration. Multiple lines of evidence were used to evaluate pre- and post-capping conditions to explore the effects that capping has had on pore water levels and downgradient groundwater quality approximately seven years after installation of a geosynthetic cover system. Field measurements and analytical data were evaluated using statistical, groundwater flow, and geochemical models. Findings demonstrate statistically significant decreasing trends of CCR constituent concentrations dissolved in groundwater that initiate with completion of the cover system.

 
May 15th, 1:30 PM May 15th, 2:00 PM

Post-closure Responses in Groundwater Quality.pdf

Grand Rapids, Michigan

Post-closure - Responses in Groundwater Quality and Chemistry Authors Mr. Chris Lalonde - United States - Stantec Mr. Jim Finley - United States - Stantec Mr. Paul Thomas - United States - Tennessee Valley Authority Abstract Is there a meaningful and measurable improvement in groundwater quality following closure in place of a coal combustion residuals (CCR) unit by installation of a geosynthetic cover system? Using data collected at a closed CCR unit, we examined the response of pore water levels within the CCR material and groundwater quality along the downgradient edge of the CCR unit following closure in place that included capping to prevent infiltration. Multiple lines of evidence were used to evaluate pre- and post-capping conditions to explore the effects that capping has had on pore water levels and downgradient groundwater quality approximately seven years after installation of a geosynthetic cover system. Field measurements and analytical data were evaluated using statistical, groundwater flow, and geochemical models. Findings demonstrate statistically significant decreasing trends of CCR constituent concentrations dissolved in groundwater that initiate with completion of the cover system.