COMPLIANCE INFO - Laserfiche WebLink

Home Browse Search

Proposal Workplan Page 3 TEIXEIRA SOUSA—GROUNDWATER ASSESSMENT December 18,2006 WKA No.: 3PRO6195 This work plan assumes that based on field observations, one soil sample per boring will be retained and potentially be submitted for laboratory analysis. Based on our previous experience at the Site, we assume that groundwater should be encountered at depths ranging from 10 to 15 feet below ground surface. Grab groundwater samples will be collected from the terminal depth of each boring, approximately 15 to 20 feet below ground surface, where groundwater is encountered. During the collection of grab groundwater samples, field parameters for pH, turbidity, dissolved oxygen, electrical conductivity, and temperature will be collected and recorded. The final depth-to-water of the groundwater surface will be measured using an electronic sounder with a tape graduated in 1/100ths of a foot. After sampling, each boring location will be backfilled with a bentonite slurry and capped, in accordance with SJCEHD requirements. To estimate the local direction of groundwater flow and a groundwater gradient, a limited number of the sampling locations will be marked and surveyed to establish relative ground surface elevations. Groundwater elevations and a gradient will then be calculated using the survey data in conjunction with depth-to-water measurements obtained during the soil and groundwater grab sampling. The direction of groundwater flow will also be estimated from the results of the groundwater elevation calculations. Using the proposed sampling methodologies, minimal soil cuttings and purge water will be generated, which we assume will not require profiling and off-site disposal to a local landfill. Task 3: Laboratory Analysis Selected soil and groundwater samples will be submitted to a Department of Health Services-certified laboratory and analyzed on a standard 10-day turn-around basis. All samples will be placed in an ice-chilled cooler after collection and submitted within laboratory-specified holdtimes for analysis. Per the tentative MRP, selected soil samples will be analyzed for the following parameters: • Specific conductivity(EPA 120.1) • Nitrate as nitrogen (EPA 300.0) • Ammonium as Nitrogen(EPA 300.0) • Phosphorus (EPA 365.2/SM 4500-P) • Potassium (EPA/STDM) • pH (EPA 150.1) INK WALLACE•KUHL Er ASSOCIATES INC.