Results of geophysical investigations near the Norman, Oklahoma, Municipal Landfill, 1995

Abstract

Image maps of apparent conductivity values for horizontal magnetic dipole modes for the EM31-D, (a), and EM34-3, (b) and (c), for stations on the grid near the Norman landfill west cell. The small dots in each image are the station locations ... 11. Image maps of apparent conductivity values for vertical magnetic dipole modes for the EM31-D, (a), and EM34-3, (b) and (c), for stations on the grid near the Norman landfill west cell. The small dots in each image are the station locations ..

Revealing stratigraphy in ground‐penetrating radar data using domain filtering

“…Figure 5 shows a strong reflection (between the unfilled boxes) from 30 to 40 ns. An event at this depth was observed 2 km downstream by Lucius and Bisdorf (1995) during the spring. Soil borings were used to correlate it with the top of the water table at a depth of 1 m (using a time-to-depth conversion velocity of 0.075 m/ns).…”

“…In the present survey environment, wave propagation is more significant than conduction because of the low conductivity in the subsurface. Conductivity measurements using an EM-31 system 2 km downstream from our study site show that saturated sand of the Canadian River alluvium has a conductivity of 15-20 mS/m and a dielectric constant of 9-16 (Lucius and Bisdorf, 1995). Taking the higher value for conductivity and the lower value for the dielectric constant, the transition frequency above which propagation dominates can be estimated (Annan, 1992) by…”

“…Apparent velocities are 0.30, 0.12, and 0.30 m/ns, respectively. Comparable direct ground wave velocities of 0.075-0.10 m/ns were measured by Lucius and Bisdorf (1995) in a somewhat more variable alluvial environment 2 km downstream. The separation in time of arrivals expected on the constant offset profile can be estimated from the CMP trace at 1.2 m (Figure 4a, half arrow).…”

Ground and Surface Water Developmental Toxicity at a Municipal Landfill: Description and Weather-Related Variation

“…The survey assessed the apparent conductivity of the alluvium, which is determined by several factors including the porosity, pore space saturation, and the conductivity of the water or leachate in these pore spaces. The survey indicated an area of higher conductivity downgradient of the landfill which was interpreted as being caused by leachate flowing from the landfill and mixing with the water in the alluvium (Lucius and Bisdorf, 1995;Fig. 5).…”

“…In 1985 the landfill was closed, capped with clay, and vegetated (Callender et al, 1993). In 1994 the landfill site was selected to be the focus of the Toxic Substances Hydrology Program of the United States Geological Survey (USGS), Water Resources Division (Lucius and Bisdorf, 1995). Other researchers have identified more than 40 semi-volatile and non-volatile compounds (Dunlop et al, 1976) as well as 35 volatile compounds (Scott Christenson, USGS, personal communication) (Table 1) in the groundwater downgradient from the landfill.…”