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16 <br /> Phase 2 Soil Sampling of Tidal Channel Alignment:Smith Island Estuary Restoration Project • <br /> June 5,2015 <br /> Page 3 of 3 <br /> directly with a waste disposal firm. It is anticipate that the waste water can be temporarily securely <br /> stored locally at the Water Pollution Control Facility for collection directly by the disposal vendor. <br /> Soil removed from the sample locations will be placed back into the borehole,as best as possible, <br /> from which the sample was collected. <br /> Number and Depth Samples <br /> Soil samples will be collected at approximately 40 locations at the project site.A 5-foot below grade <br /> sampled_tnalll�_e llected at all 401_Qcations.Additionallyta near-surface(0.5 to 1 foot below grade) <br /> sample will be collected at 20 of the 40 locations.Our objective is to spatially distribute the locations <br /> in a manner that will provide the data necessary to make informed disposal and/or reuse decisions, <br /> as per the attached draft sampling plan figure. <br /> Analytical <br /> The collected and preserved(ice)soil samples collected in the field will be delivered to an <br /> environmental testing laboratory under chain of custody protocols.Based on the findings of soil <br /> sampling conducted at the Smith Island Restoration Project we propose to limit our analytical <br /> testing to total lead and arsenic by EPA Method 6020.The samples will be analyzed on an expedited <br /> 3 to 5-day turnaround time to facilitate decisions on modifications to the 60%design based on the <br /> results. <br /> Task 2: Data Analysis and Reporting <br /> The arsenic and lead results will be placed in tables and on figures so that their horizontal and <br /> vertical distribution can be observed.The concentrations will be compared to Ecology's MCTA <br /> Method A cleanup levels for both arsenic and lead and the Washington Administrative Code(WAC) <br /> Marine Sediment Management Standard(SMS)threshold for arsenic.Arsenic's SMS threshold is a <br /> concentration or sediment cleanup level(SCL)that below which will result in no adverse effects, <br /> including no acute or chronic adverse effects on biological resources and no significant health risk to <br /> humans. <br /> A technical memorandum will be prepared that will include tables and figures,along with an <br /> interpretation of the data,and recommendations on how to best manage excavated soils whether <br /> they are used on site or disposed off-site.The recommendations will also include any additional <br /> actions that may be needed to facilitate the off-site disposal of contaminated soil should that be <br /> necessary. <br /> 79 <br />