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Mr. Chris aressel pB1072.400.0002 gcinuary 27, 2014 rrage 5 described above. Between each of the sampling locations, the drilling rods and well screen will be decontaminated by washing with Alconox and water solution and rinsing with deionized water. r p to 28 groundwater samples plus 20 n A/n C samples, collected from the temporary boreholes using direct -push technologies, will be analyzed for s I Cs. Five field blanks and five trip blanks will also be analyzed for s I Cs. Costs for the laboratory analyses assume i evel Is data packages will be provided by the laboratory, as required by the IaEM s om Following installation of the temporary sampling points, eight deep and shallow nested monitoring wells will be installed on -pite to further evaluate the potential presence of Cl Cs in groundwater along the western perimeter of the pite (along prairie Avenue /Chapin ptreet); and off -pite to further evaluate the downgradient distribution of s I Cs north and east of the pite. Final locations of permanent monitoring wells will be determined during proposed meetings with the City, its outside counsel, and Mr. Ed ptefanek of t eaver -Boos Consultants. poil borings associated with the proposed monitoring wells will be drilled using 4.25 -in., inside - diameter hollow -stem augers and continuously sampled using 24 -in. split -spoon samplers to the appropriate depth (i.e., either 30 feet bgs or 45 feet bgs). pimilar to the locations of the direct -push sampling points, the final locations of the monitoring wells may be modified based on field observations. Although the deeper boring at each location will be continuously sampled, soil samples are not proposed to be submitted for laboratory analyses as part of the monitoring well installation. Monitoring wells will be constructed of pchedule 40 rm C slotted screens and risers. I nce the targeted depth has been reached, the well column will be slowly lowered to the base of the borehole. A clean silica quartz sand filter pack will be placed around the screen and will extend no more than two feet above the top of the screen. podium bentonite chips or pellets will then be placed on top of the sand pack. Above the chips or pellets, a thick bentonite slurry will be pumped into the annular space using a tremie pipe to a depth of approximately three feet below ground surface. The remaining three feet will be filled with concrete to anchor a flush -mount manhole. Monitoring wells will be developed following installation to remove fines that may have entered the well screen or filter pack during installation. t ell development activities will continue until pH, temperature, and conductivity have stabilized for three consecutive well volumes, or until five well volumes have been removed, whichever is greater. aevelopment waters will be collected and stored in a al T approved 55- gallon drum. Costs to remove, transport, and dispose of approximately 52 55- gallon drums of containerized groundwater and drill cuttings (which are presumed to be non - hazardous) are included in this task. Following the installation of these newer monitoring wells, the top of casing and ground elevations of the new wells will be surveyed so that the groundwater elevations measured in these wells can be compared relative to the other wells in the monitoring network. Task 4 Conduct Quarterly Groundwater Monitoring Following the installation of new monitoring wells, a routine of quarterly groundwater sample collection from all monitoring wells is proposed. This will establish a baseline and, after several quarters, will begin to allow for seasonal trend analysis. After four to six quarters, a sufficient trend should be established to allow for an analysis of whether certain monitoring wells can be removed from the quarterly sampling routine, with IaEM concurrence.