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El 40 Technical Approach Page T Task 7 PREPARE AND ACQUIRE STATE LANDS LEASE(S) FOR BORROW AREAS ATM will prepare legal descriptions for the three borrow areas identified in the Sand Source Investigation and submit applications requesting State of Florida Submerged Lands Leases to the Division of State Lands. It is anticipated that the drawings and requests will be processed concurrently with the FDEP Joint Coastal permit applications. A 10 -year lease period will be requested for each borrow area. Task 8 DETAILED VIBRACORING INVESTIGATION OF NORTH BORROW AREA Task 8.1 Obtain Vibracores in Target Areas 'The number of cores will be optimized based on distance from shore, planform geometry of the candidate site(s), water depth, anticipated core lengths necessary for logging, sampling and archival, and apparent material composition. It is assumed that vibracores will be collected during 2 field days and that 12-16 vibracores will be recovered. It is estimated that, for the purposes of this study, a specifications -level spacing will initially be utilized in the areas of potential sand deposition. Should the field acquisition of vibracores reveal consistently high quality (and in -field estimates of quantity) material in one or more of the candidate sites, efforts will be intensified in those areas to reduce the grid coverage area and, in effect, produce a plans -and - specifications -level distribution of vibracores. Construction plans and specifications -level vibracores should be acquired on an approximately 500 to 1,000 ft grid completely covering the area of anticipated sand excavation. A conservative estimate of six to eight 20 -foot vibracores per field day is assumed over the course of the single mobilization effort. The vibracoring effort entails positioning a Coast Guard certified coring vessel over a previously determined (or ATM -directed) coordinate set offshore. Once in position, the coring system utilizes a pneumatic impacting piston mounted on the top of a core barrel constructed of steel or aluminum pipe and felted with an internal plastic liner to contain the sediment core sample. The core barrel is mounted on a stable platform and serves additionally as a guide to the vibrator and core barrel. The coring system is deployed to the ocean bottom and retrieved utilizing a deck -mounted hydraulic crane. DGPS positioning of the core sample retrieved is recorded along with record of the barrel penetration into the seabed. The procedure is then repeated following removal of the plastic liner from the barrel visual inspection of the material contained within the liner, and ATM acceptance or reiection of the recovered' oVli_ '�-• -5 'iM bc: �.".-u�giiircu uy file vibracoring contractor at U._t i i-.:. no additional cost to Indian River County.