REMOVAL 2011 CLOSURE IN PLACE - Laserfiche WebLink

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' 2.0 IN-PLACE UST CLOSURE This section describes the general methodology for the proposed in-place UST closure. This section also describes soil sampling activities. The objective of this section is to establish protocols for conducting the In Place Closure and assorted sampling. 2.1 IN PLACE CLOSURE In-Place UST Closure will be conducted by All Chemical Disposal, Inc. (All Chem). The following is the proposed methodology for the in-place closure. ' ➢ Remove sidewalk ➢ Excavate tank covering and expose tank top. ' ➢ Check LEL levels within the UST and apply Organic Vapor Suppressant and Dry Ice as needed to dispense any vapor from the UST. ➢ Remove any UST piping and related equipment necessary to gain access to the ' interior of the UST. Remove any debris and contaminated solids currently filling the UST, with plastic shovels and segregate within 55-gallon open top, DOT rated drums. t ➢ Clean interior of UST with a simple green and water solution with rags & a mop handle. Containerize any equipment used to clean the UST within 55-gallon open top, DOT rated drums. ➢ Backfill the cleaned UST shell, using a 1 —2 sack sand slurry (CDF) as warranted. 2.2 SOIL SAMPLING ' Following In-Place Closure, PSI will collect soil samples from beneath the closed UST. As there is an existing trench adjacent to the UST, PSI proposes that the trench be further ' advanced to the tank bottom at the two ends of the UST. PSI will then use a hand-auger to create an angle boring that will advance to two feet underneath the two ends of the UST. PSI will then collect soil samples with a drive sampler at the bottom of the boring. A total of ' two hand-auger borings would be completed. Following completion of the hand-auger borings, they will be backfilled with hydrated bentonite chips. Groundwater is not expected to be encountered, as historical groundwater levels at the site have been approximately 40 ' to 60 feet below land surface. Upon retrieval of the soil samples, the ends of the sample tube will be covered with Teflon ' sheets and capped with polyethylene end caps. The samples will be labeled and placed in a chilled cooler pending delivery to the laboratory for analysis. Soil samples will be assigned identification numbers such as 61-5, where B1 indicates the boring number and t 5 indicates that the sample was collected at 5 foot bgs. The samples will be labeled with the sampling designation, depth, date, client name, and project number. ' 2