6C (6) - Laserfiche WebLink

Home Browse Search

Ivy Tower Phase II February 27, 2012 Page 4 of 7 (ppm). All data associated with the field screening of VOCs will be recorded for future reference (Soil Boring Logs). In addition, a portion of each discrete sampling interval will also be collected for submittal to a laboratory. Wightman Petrie proposes to submit two (2) soil samples from each of the seven (7) boring locations based on the PID field screening results and /or other indications of the presence of potential contamination (visual or olfactory). In the event that field screening with a PID, visual or olfactory observations do not indicate the presence of contamination; the soil sample collected from the upper two (2) feet within the boring, as well as the interval immediately above the soil /groundwater interface will be submitted for laboratory analysis. Each of the soil samples selected for laboratory analysis will be analyzed for the presence of Volatile Organic Compounds (VOCs) via EPA Method 8260, and carcinogenic Polynuclear Aromatic Hydrocarbons (cPAHs). Wightman Petrie will utilize IDEM guidance Terra -Core Methods to collect soil samples from each discrete sampling interval for the analysis of VOC constituents. All soil samples will be labeled, packed on ice and forwarded to the laboratory under chain - of- custody procedures. Temporary Geoprobe Well Installation for Groundwater Sampling Wightman Petrie proposes to convert each of the seven (7) Geoprobe soil borings to temporary wells with insertion of a Geoprobe groundwater sampling device, which allows for the extension of a stainless steel slotted screen for collection of a groundwater sample from the point at which the saturated or water - bearing zone is encountered. For this proposal, Wightman Petrie has assumed that the water - bearing zone will be encountered within 25 -feet of land surface. We would also note that each of the three (3) borings /temporary wells installed within the vacant lot south of Building 113, as well as the boring /temporary well proposed for the grassy area west of Building 112 include the sampling of groundwater at various depths, based on the presence of a chlorinated solvent plume being identified in at a depth approximately 10 to 15 ft. greater than the depth at which the groundwater aquifer was originally encountered (i.e., 40 feet below ground surface). Once installed, each temporary well would be purged until such time as the water discharge becomes relatively free of solids or until at least three (3) gallons of water has been removed. Wightman Petrie proposes that groundwater from each of the temporary wells be analyzed for Volatile Organic Compounds via EPA Method 8260, and carcinogenic PAHs via EPA Method 8270 SIM. For those temporary wells at which multiple groundwater samples will be collected (total of four); Wightman Petrie proposes that groundwater sample from the deeper of the screened intervals be analyzed for the presence of VOCs only. Each groundwater sample will be appropriately labeled, packed on ice, and forwarded to the laboratory (priority overnight delivery) under chain -of- custody procedures. Analysis will also include the analysis of a water sample for QA/QC purposes (Volatile Organic Compound only). Wightman Petrie will plug the boreholes /wells with bentonite once soil and groundwater sampling activities have been completed. Reporting Upon receipt of the laboratory analyses, data will be reviewed and tabularized. Comparison of the data for each respective chemical constituent will be made to the Risk Integrated System of Closure (RISC) Default Closure Values for Residential and Industrial /Commercial Properties. Upon completion of the initial data review, a "Letter Report" will be prepared which presents the sample collection and analytical methodologies used during the field phase of the assessment. Copies of the sample location maps, tabulated data and comparison to RISC Default Closure Values will also be incorporated. Recommendations for any additional assessment activities will be made for review and comment.