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monument locations will be provided . All work performed shall be consistent with the FDEP Statewide Coastal Monitoring Program, Regional Data Collection and Processing Plan. Morgan & Eklund , Inc. will perform the survey data acquisition and data reduction under subcontract to ATM . TASK 7. 2: BATHYMETRIC SURVEYS OF THE BORROW AREA The offshore borrow area used for the beach nourishment project will be surveyed periodically to assess the infilling rate. Surveys will be conducted within 60 days post- construction (already contracted to Great Lakes Dredge & Dock Company) , and at year 3 post-construction . Soundings for the bathymetric survey will be taken at a minimum of 50-foot intervals with sounding lines no more than 500 feet apart . The survey will extend a minimum 500 feet beyond the limits of the borrow site on all sides of the borrow area . Bathymetric data will be collected in accordance with prescribed USACE standards for hydrographic surveying . For the three-year post-construction survey , ATM's 25 ' Parker survey boat, an Odom Hydrotrac Fathometer, and a Trimble Differential Global Positioning System will be utilized . The fathometer and DGPS will be interfaced to Coastal Oceanographics' HYPACK hydrographic software . Bar check calibrations of the survey fathometer will be performed daily throughout the field operation to ensure that accurate water depth data are being acquired . Tides will be monitored and recorded for post processing of the bathymetric data . The location of the tide monitoring station will be subject to field reconnaissance , survey bench mark locations, and proximity to the borrow site . The gauge will be installed in water depths sufficient to conduct vertical leveling in coordination with a shore-based survey crew. Vessel speed shall not exceed four knots to ensure optimal data signal acquisition . The deliverable for this bathymetric survey task will include reduced tide-corrected data delivered in electronic format and on a contour plot. A bathymetric contour plot will be generated from the acquired hydrographic survey data , with two-foot intervals represented as an overlay in AutoCAD at 1 " = 200' . A letter report of field methods utilized and dates of survey will be transmitted along with the referenced digital files . TASK 7. 3 : SEDIMENTATION MONITORING Potential changes in overall sedimentation will be quantified through the installation of non-corrosive stakes adjacent to selected hardbottom areas , followed by periodic measurement of sedimentation levels from a predetermined measuring point on the stake to the sediment surface. Stakes will be located inside the project area at DEP Reference Monuments R4 , R-89 R- 12 , and T-16 within the predicted equilibrium toe of fill . Additional stakes will be located outside of the project area at R- 22 and R-25 in similar cross-shore locations . This monitoring will allow for the assessment of changes in bottom sediment levels over time . Sedimentation levels will be measured coincident with the annual monitoring surveys for the first two years following construction . All appropriate safety measures will be undertaken to ensure the installation and placement of the stakes does not create a hazard to swimmers or surfers . CAWINDOMTEMPWnbersand Post-Construction Services Contract Amendment k6 - Reduced Scope 03-12-03.doc 13