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Mr. Chris aressel pB1072.400.0002 gcinuary 27, 2014 rrage 6 In the meantime, however, this estimate assumes that quarterly groundwater samples will be collected from all existing and newly - installed monitoring wells on- and off -pite (an estimated total of 37 monitoring wells) for 8 quarters. d roundwater samples will be collected from all newly installed monitoring wells and submitted to the laboratory for s I C analysis using r .p. En-4 Method 8260. auplicate samples will be collected at randomly selected monitoring well locations. Field /equipment blanks will also be collected and submitted along with a trip blank for analysis as part of n A/n C of field procedures. rrurge and decontamination waters will be collected and stored in r .p. al T- approved 55- gallon drums. Costs to remove, transport, and dispose of eight 55- gallon drums of containerized groundwater and drill cuttings (which are presumed to be non - hazardous) are included in this task. For the proposed sampling events, in lieu of traditional low -flow sampling methods that have been employed at the pite previously, Hull proposes to deploy passive diffusion bag (ma B) samplers in all monitoring wells, which are a significantly more cost - effective sampling methodology that has been accepted by IaEM. rraBs are polyethylene bags filled with analyte -free water that are hung in monitoring wells for approximately 14 days. Field personnel return to the monitoring well, retrieve the sampler, and collect the sample by filling sampling vials in the same manner as traditional methods. pignificant savings are realized by reducing mobilization, purging, and sampling time; by minimizing the volume (and thereby cost and environmental footprint) of field materials such as low -flow tubing; and by eliminating most equipment rental costs. iaboratory analytical subcontractor costs for this Task include the cost of moBs for each well, and for i evel Is n A/n C reporting by the laboratory. This estimate assumes that the City and Hull will succeed in gaining IaEM approval to cease sampling groundwater for metals, which should be acceptable given the proposed restriction of groundwater use as discussed in Task 5 below. A brief draft letter report documenting the results of each quarterly sampling event will be prepared and submitted to the Client for review. I nce the draft letter report is reviewed by the Client and finalized by Hull, a copy will be submitted to the IaEM s om Task 5 Evaluate GW Remedies Restrict GW Use, and Amend the RWP I nce the extent of downgradient groundwater impacts, the current status of groundwater impacts on -pite, and the potential off -pite [i.e., south and southwest (upgradient)] sources that may be contributing to groundwatHr HntHring thH 6itH's southHrn Eoundary arH better understood by the activities to be completed in steps 3 and 4 above, the prior remedy (i.e., EOST") that was pilot tested at the nearby I liver Industrial 3ark — and shown to EH HI I I -FtivH — will EH Hvaluated for additional applications. As the groundwater in- situ treatment technology market has evolved in the last 3 -4 years, we will commit to evaluating similar chemistries that may offer a cost and /or effectiveness advantage. aepending upon the results of the groundwater sampling proposed herein, the actual necessity of a groundwater remedy (i.e., beyond engineering and /or institutional controls) will be evaluated first and foremost prior to the recommendation of any groundwater remediation technology. As we have discussed previously, Hull recommends that the City effectively render incomplete the groundwater ingestion exposure pathway at and in the vicinity of the pite by ensuring that pt. g:)seph County Code 52, pection 52.042 is enforced, which prohibits the installation of wells for potable use where a municipal water source is available, and pection 52.043 is implemented for the vicinity of the pite, which governs the establishment of an Administrative Control Area (ACA). The language of pection 52.043, whereby an ACA is established, contains additional relatively far- reaching yet flexible provisions to further restrict exposure to groundwater when a threat to human health may be present. Hull and the City's outsidH FounsH haves alrHady HngagHd thH 6t. gDseph County Health aepartment to begin the process of establishing an ACA, and will continue to pursue this effort. t e are confident that once the