FIELD DOCUMENTS - Laserfiche WebLink

Home Browse Search

v normally occurring background concentrations as described in Summary of Typical Metals Concentrations in Soils and Surficial Materials from U.S.G.S. Professional Paper 1270 for the Conterminous United States, dated April 28, 1992. Soil samples collected from the soil cuttings of the drywells NW, SW, SE, and NE contained no detectable concentrations of VOCs, SVOCs, TPHg, TPHd, or TOG. The soil samples collected from the soil cuttings of the drywells NW, SW, SE, and NE contained low concentrations of various metals. The concentrations of metals detected in these samples were consistent with the normally occurring background concentrations described above. Analytical results of soil samples are summarized in Table 1 and laboratory data sheets are contained in Attachment 1. Borehole Backfillin¢ Once analytical results were received ATC verbally requested regulatory approval to backfill the borings from Mr. Ron Rowe of PHS/EHD on July 19, 2000. With PHS/EHD approval, the drywells were backfilled with a two-sack sand slurry from the bottom to approximately 7 to 8 feet bgs. Approximately 50 cubic yards of sand slurry was used to backfill the drywells to this depth. The drywells were then capped with a five-sack cement slurry containing no fly ash from 7 to 8 feet bgs to within approximately one foot of the surface. Approximately 9.5 cubic yards of cement slurry was used to backfill the drywells to the near surface. Both slurry mixtures were delivered to the site by an aggregate company and placed directly from the mixing truck into the boreholes. RECOMMENDATIONS Based on the analytical results and field observations, the subsurface at the site has not been impacted by the use of the drywells. ATC recommends that this site be granted closure and a No Further Action letter be issued as soon as possible. The stockpiled soil cuttings should be used to top off the borings and the remainder of the soil cuttings should be spread out on site.