REMOVAL REMOVAL 1990 - Laserfiche WebLink

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ti,#& 6N tl/rO A.) yilE nl4,W zn4o to, V, p;; 1 r, 19 da Soil samples will be obtained from beneath the tank and the tank piping system following their removal. Due to the anticipated depth NPEN excavation, sampling personnel will not enter the excavation. \/J(,PALTH samples will be collected from the excavation bottom and sidewa s using the Contractor's backhoe bucket at locations to be indicated by sampling personnel. Samples will be collected by driving a brass liner into the soil in the Contractor's backhoe bucket. The brass liners will be covered on both ends with Teflon sheets which will be secured in place with plastic end caps and duct tape. Each brass liner will be labeled to identify sampling location, date of collection, time, initials of collector, and any other pertinent information. The brass liners will then be placed in a cooled ice chest and sent to a state certified laboratory for analysis. A chain -of -custody form will be filled out concurrently with sample collection and included with the samples during shipment. Soils removed from the excavation by the Contractor will be monitored for the presence of organic vapors. This monitoring will be performed by placing samples of soil from the backhoe bucket into self-sealing plastic containers and allowing the containers to sit in a warm area for 5 to 10 minutes. Organic vapor concentrations present in the sample container headspace will be measured by inserting the probe of an organic vapor analyzer into the plastic container. If there are visible indications that the tank has leaked (stained soil, visible tank product, or holes noted in the tank), we will utilize the headspace monitoring technique to identify soils to be removed by the Contractor. If leakage has occurred, it is anticipated that soils samples from various depths will be collected for both headspace analysis and laboratory analysis to evaluate attenuation rates of tank product. If the leakage appears limited in extent and depth, we will identify soils that should be removed or sampled. If significant leakage has occurred, we will provide recommendations for interim measures such as temporary backfilling of the excavation. Analysis of four soil samples for TPH and purgeable aromatics utilizing gas chromatography with a flame -ionization detector (GC/FID) will be performed. The anticipated sample locations are as follows: two samples from the bottom of the excavation and two samples from beneath the piping. To expedite excavation and backfilling, a 48-hour laboratory analysis turn -around time is budgeted for these analyses. If the tank has leaked a significant amount of product, additional soil samples will be collected as needed to evaluate variations of product concentrations in soils with respect to depth. This information will be useful in determining the need for and extent of soil cleanup. WP015:882526.GC 882526.01 11 April 1990