The Indiana Department of Environmental Management (IDEM) approved a pH Variance for a Type III Fly Ash Landfill at a client’s station in the state of Indiana. As part of the permit, a groundwater monitoring program, which includes sampling of three (3) downgradient wells, is ongoing at the site. Because of local physiography, an upgradient monitoring well could not be installed. To obtain data regarding background concentrations, groundwater samples were collected from three (3) downgradient wells before fly ash was emplaced in the landfill. Background levels of constituents of concern were developed using analytical data from these wells.
AGES staff began work on this project over 18 years ago and have been extensively involved in the project since then. To determine if statistical increases in concentrations of constituents of concern in groundwater had occurred at the site, an intra-well approach was used to compare concentrations at each well before and after the emplacement of ash. Statistical analyses for data before and after ash emplacement were performed per IDEM guidance. Parametric and non-parametric analyses were used, including the Mann-Whitney U-test, Student’s T-test, and temporal trend analysis (as required by 329 IAC 10-29-5). Throughout the course of the project, AGES staff have negotiated with IDEM, responded to their comments on the groundwater monitoring program, and successfully negotiated a reduction in both the frequency (from quarterly to semi-annually) and in the number of analytical parameters. Using qualitative methods of evaluation, AGES has demonstrated that statistical increases in constituent concentrations have not occurred at the site. As a result, remedial action has not been required. In combination with the scope reductions in the program, this has resulted in significant cost savings to the client.
AGES has also been engaged by a regional law firm to provide litigation support for this site, including expert witness testimony, depositions, and technical review.
1.) Demonstrated expertise in the use of various statistical methods (both parametric and non-parametric) for evaluation of groundwater quality at a fly ash landfill.
2.) Negotiated with IDEM to allow for a unique, intra-well approach for monitoring that uses qualitative analyses in lieu of a classic statistical approach.
3.) Long-term (over 18 years) client relationship that resulted from implementation of a programmatic approach that includes use of AGES’ project management tools.