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Indian River County Public Works Department Proposed North County Regional Park June 15 , 2000 Due to the likelihood of a high ground water table, the first 1 foot of fill should be a uniform free draining granular soil (clean sand containing less than 3 % material finer than the No . 200 sieve) and be placed in layers not to exceed 15 inches loose measure and compacted as outlined above . Provided a dry, stable surface is achieved, the remaining fill may contain up to 7% material finer than the No . 200 sieve. Sufficient compactive effort should be applied to obtain a minimum of 95 % density for all of the fill layers . Sufficient soil density tests should be taken to verify the density has been achieved. With the above criteria satisfied, a standard pavement section may be constructed. All methods and materials should be in accordance with the latest version of the FDOT Standard Specifications for Road and Bridge Construction, UTILIZATION OF SOIL FROM LAKE EXCAVATIONS As noted in the project description, soil to be excavated from the lakes will be used as site fill. The soils in the upper 2 to 2 . 5 feet designated on the boring logs as fine sands dry rapidly and compact easily, even under wet conditions, and have a high permeability rate . These soils are excellent for building foundation or roadway fill. The soils designated as fine sands with traces of silt and clay or slightly silty, slightly clayey will take some drying time before they can be compacted and they have a relatively slow permeability rate . Soils designated as silty, clayey fine sands contain appreciable amounts of silt and clay (we estimate combined silt/clay content in the 12% to 20% range) . They do not drain well and are difficult to compact when wet and have a very slow permeability rate . Although these soils are technically suitable for use as fill, considerable drying time in stockpiles will be necessary. Use of these soils in structural areas often results in project delays. If sand with minimal silt and clay content is needed, we recommend that dredging be considered . If the lakes are dredged, it should be feasible to perform the dredging in a manner that would remove the majority of the silt and clay from the soil. If this approach is to be taken, we recommend consulting with a contractor familiar with dredging these type soils. CLOSURE This report has been prepared in accordance with generally accepted foundation engineering practices. The recommendations presented herein are based on the data obtained from the soil borings previously described . No other warranty, expressed or implied, is made. We do not guarantee project performance in any respect, only that our work meets normal standards of professional care . This report may not account for all possible variations that may exist between conditions observed in the borings and conditions at locations that were not explored. The nature and extent of any such variations may not become evident until fin-ther explorations are made or 5 Fraser Engineering and Testing, Inc.