Mineral Saturation Indices and X-ray Diffraction analysis for groundwater and solids from extraction and monitoring wells at a confined disposal facility, East Chicago, Indiana

The U.S. Geological Survey (USGS), in cooperation with the U.S. Army Corps of Engineers (USACE), conducted a study from June 2014 through November 2014 to identify the hydrologic, chemical and microbiologic processes affecting declining pump performance and frequent pump failure at a confined disposal facility (CDF) in East Chicago, Indiana. To better understand the causes behind declining pump performance, data were collected to describe the geochemistry and microbiology of groundwater and solids collected from extraction and monitoring wells at the CDF. Mineral-saturation indices were computed using the computer program PHREEQC (Parkhurst and Appelo, 2013) to determine if chemical constituents in groundwater wells were present in sufficient concentrations to abiotically precipitate the minerals identified in SEM and x-ray analyses described in SIR 2018-5073 (Bayless and others, 2018). The PHREEQC input and output files used for this analysis are included in the model archive, "PHREEQC program used to calculate mineral-saturation indices from groundwater quality data collected at a confined disposal facility in East Chicago, Indiana". Qualitative and quantitative x-ray diffraction (XRD) analyses were done on eight samples of pump scrapings collected from five extraction wells (EW-4C, EW-4D, EW-11D, EW-20D) and one monitoring well (MW-4B). The data set, "X-ray diffraction trace analysis of solid phase samples collected from groundwater wells at a confined disposal facility in East Chicago, Indiana", includes a comma-seperated value (.csv) file of XRD data analyzed at the USGS Rock Kinetics Laboratory in Menlo Park, California. To fully understand the methods, results, and interpretations for the information presented in this data release, users are encouraged to read the original Scientific Investigations Report (Bayless and others, 2018) SIR 2018-5073, https://doi.org/10.3133/20185073. REFERENCES CITED: Bayless, E.R., Cole, T.R., Lampe, D.C., Schulz, M.S, Travis, R.E., and Buszka, P.M., 2018, Geochemistry and microbiology of groundwater and solids from extraction and monitoring wells and their relation to well efficiency at a Federally operated confined disposal facility, East Chicago, Indiana: U.S. Geological Survey Scientific Investigations Report 2018-5073, https://doi.org/10.3133/20185073. Parkhurst, D.L. and Appelo, C.A.J., 2013, Description of input and examples for PHREEQC version 3 -- A computer program for speciation, batch-reaction, one-dimensional transport and inverse geochemical calculations: U.S. Geological Survey Techniques and Methods, book 6, chap. A43, 497 p., http://pubs.usgs.gov/tm/06/a43/.