In June 2018, U.S. Geological Survey (USGS) in cooperation with the U.S. Environmental Protection Agency (EPA) collected geophysical measurements to help evaluate the suitability of a proposed landfill site for disposing mine-waste materials in Fredericktown, MO. Two survey profiles were collected, each including dipole-dipole and Wenner-Schlumberger configurations. For each survey a total of 28 electrodes spaced 1.0 meter (m) apart were used. During the ERT measurement, current is injected through two current electrodes and voltage is measured sequentially across multiple pairs of potential electrodes; the known current and the measured voltages are used to determine the apparent resistivity of the subsurface. Inverse modeling of ERT survey results provide profiles of resistivity that can be interpreted for subsurface layers. This data release provides the raw ERT data and output from inversion.

In June 2017, U.S. Geological Survey (USGS) collected geophysical measurements to help map variations in electrical properties to infer shallow flowpaths and storage zones influenced by residual spilled unconventional oil and gas (UOG). Two survey profiles were collected, each including dipole-dipole and Wenner-Schlumberger configurations. For each survey a total of 56 electrodes spaced 1.0 meter (m) apart were used. During the ERT measurement, current is injected through two current electrodes and voltage is measured sequentially across multiple pairs of potential electrodes; the known current and the measured voltages are used to determine the apparent resistivity of the subsurface. Inverse modeling of ERT survey results provide profiles of resistivity that can be interpreted for subsurface layers. This data release provides the raw ERT data and output from inversion.

In June 2017, U.S. Geological Survey (USGS) collected geophysical measurements to help map variations in electrical properties to infer shallow flowpaths and storage zones influenced by residual spilled unconventional oil and gas (UOG). Two survey profiles were collected, each including dipole-dipole and Wenner-Schlumberger configurations. For each survey a total of 56 electrodes spaced 1.0 meter (m) apart were used. During the ERT measurement, current is injected through two current electrodes and voltage is measured sequentially across multiple pairs of potential electrodes; the known current and the measured voltages are used to determine the apparent resistivity of the subsurface. Inverse modeling of ERT survey results provide profiles of resistivity that can be interpreted for subsurface layers. This data release provides the raw ERT data and output from inversion.

In June 2018, U.S. Geological Survey (USGS) in cooperation with the U.S. Environmental Protection Agency (EPA) collected geophysical measurements to help evaluate the suitability of a proposed landfill site for disposing mine-waste materials in Fredericktown, MO. Frequency domain electromagnetic (FDEM) induction data were collected along the edge of the water. The antenna was placed on a plastic frame and held approximately 1 m above the water surface. The antenna was mounted on a raft that was towed behind a canoe. All unprocessed and processed data including the in-phase and quadrature components in parts per million, electrical conductivity (EC) in milliSiemens per meter (mS/m), and magnetic susceptibility in parts per thousand are served in this data release. In addition, the data were inverted to generate depth dependent estimates of conductivity along the profiles. An analysis of the depth of investigation indicated the FDEM reliably estimated conductivity values to depths of about 3 m below the water surface. These output data are also served in this data release. All unprocessed and processed data including the in-phase and quadrature components in parts per million, electrical conductivity (EC) in milliSiemens per meter (mS/m), and magnetic susceptibility in parts per thousand are served in this data release. In addition, the data were inverted to generate depth-dependent estimates of conductivity along the profiles. An analysis of the depth of investigation indicated the FDEM reliably estimated conductivity values to depths of about 3 m below water surface. These output data are also served in this data release.

In June 2018, U.S. Geological Survey (USGS) in cooperation with the U.S. Environmental Protection Agency (EPA) collected geophysical measurements to help evaluate the suitability of a proposed landfill site for disposing mine-waste materials in Fredericktown, MO. Frequency domain electromagnetic (FDEM) induction data were collected along the edge of the water. The antenna was placed on a plastic frame and held approximately 1 m above the water surface. The antenna was mounted on a raft that was towed behind a canoe. All unprocessed and processed data including the in-phase and quadrature components in parts per million, electrical conductivity (EC) in milliSiemens per meter (mS/m), and magnetic susceptibility in parts per thousand are served in this data release. In addition, the data were inverted to generate depth dependent estimates of conductivity along the profiles. An analysis of the depth of investigation indicated the FDEM reliably estimated conductivity values to depths of about 3 m below the water surface. These output data are also served in this data release. All unprocessed and processed data including the in-phase and quadrature components in parts per million, electrical conductivity (EC) in milliSiemens per meter (mS/m), and magnetic susceptibility in parts per thousand are served in this data release. In addition, the data were inverted to generate depth-dependent estimates of conductivity along the profiles. An analysis of the depth of investigation indicated the FDEM reliably estimated conductivity values to depths of about 3 m below water surface. These output data are also served in this data release.

In June 2018, U.S. Geological Survey (USGS) in cooperation with the U.S. Environmental Protection Agency (EPA) collected geophysical measurements to help evaluate the suitability of a proposed landfill site for disposing mine-waste materials in Fredericktown, MO. Frequency domain electromagnetic (FDEM) induction data were collected above the land surface along the cleared paths through the proposed disposal cell locations. The data were collected with a hand-held, multi-frequency antenna carried approximately 1 meter (m) above the land surface at walking speeds using a multi-frequency tool. All unprocessed and processed data including the in-phase and quadrature components in parts per million, electrical conductivity (EC) in milliSiemens per meter (mS/m), and magnetic susceptibility in parts per thousand are served in this data release. In addition, the data were inverted to generate depth dependent estimates of conductivity along the profiles. An analysis of the depth of investigation indicated the FDEM reliably estimated conductivity values to depths of about 3 m below land surface. These output data are also served in this data release.

In June 2018, U.S. Geological Survey (USGS) in cooperation with the U.S. Environmental Protection Agency (EPA) collected geophysical measurements to help evaluate the suitability of a proposed landfill site for disposing mine-waste materials in Fredericktown, MO. Frequency domain electromagnetic (FDEM) induction data were collected above the land surface along the cleared paths through the proposed disposal cell locations. The data were collected with a hand-held, multi-frequency antenna carried approximately 1 meter (m) above the land surface at walking speeds using a multi-frequency tool. All unprocessed and processed data including the in-phase and quadrature components in parts per million, electrical conductivity (EC) in milliSiemens per meter (mS/m), and magnetic susceptibility in parts per thousand are served in this data release. In addition, the data were inverted to generate depth dependent estimates of conductivity along the profiles. An analysis of the depth of investigation indicated the FDEM reliably estimated conductivity values to depths of about 3 m below land surface. These output data are also served in this data release.

On May 10, 2017 an electrical resistivity tomography (ERT) profile was collected on the land along the gravel path between the water and the slime impoundment associated with the former mine activities. A total of 56 electrodes, spaced 1 m apart, extended along the base of the slope. Electrode 1 was near monitoring well MW-701 and electrode 56 was near MW-702. In the ERT measurement current is injected through two current electrodes and voltage is measured sequentially across multiple pairs of potential electrodes, which is used to determine the apparent resistivity of the subsurface. In addition, induced polarization (IP) was measured to assess the presence of chargeable layers. Two surveys were collected in dipole-dipole and combined Wenner-Schlumberger configurations. Results were also combined into a merged dataset. ERT resistivity and IP surveys can be inverted to obtain resistivity profiles that can be interpreted for subsurface layers. This data release provides the raw ERT data.

On May 10, 2017 an electrical resistivity tomography (ERT) profile was collected on the land along the gravel path between the water and the slime impoundment associated with the former mine activities. A total of 56 electrodes, spaced 1 m apart, extended along the base of the slope. Electrode 1 was near monitoring well MW-701 and electrode 56 was near MW-702. In the ERT measurement current is injected through two current electrodes and voltage is measured sequentially across multiple pairs of potential electrodes, which is used to determine the apparent resistivity of the subsurface. In addition, induced polarization (IP) was measured to assess the presence of chargeable layers. Two surveys were collected in dipole-dipole and combined Wenner-Schlumberger configurations. Results were also combined into a merged dataset. ERT resistivity and IP surveys can be inverted to obtain resistivity profiles that can be interpreted for subsurface layers. This data release provides the raw ERT data.

Electrical resistivity Tomography (ERT) is a direct current geophysical method that is used to estimate the subsurface distribution of the electrical resistivity (measured in ohm-meters, or ohm-m) of a material, and is based on the assumption that measured electric potentials (voltages) near current carrying electrodes are influenced by the electrical resistivities of the underlying material (Zohdy and others, 1974; Day-Lewis and others, 2008). Bulk resistivity is controlled by lithology, porosity, degree of saturation, chemistry of groundwater, and the conductivity of earth materials at the surface. If the degree of saturation is the only expected variable, as is the case near the groundwater replenishment and reuse project (GRRP) facility, groundwater infiltration paths can be identified with sequential ERT surveys. Data from two ERT surveys (YVHDWW_L1 and YVHDWW_L2) were collected orthogonal to each other in May and September of 2019 to determine background resistivity values downslope of the GRRP facility prior to release of reclaimed wastewater to the infiltration ponds. The resistivity data are presented in native *.stg format, as well as topographic data for each electrode in *.trn format.