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fine sands, silts and clays. The placement and degree of compaction of <br />levee fill was generally uncontrolled and variable. <br />Horizon 2 is composed primarily of silty clays, sandy silts and clayey <br />silts, all with varying organic content. This horizon is intended to <br />characterize young sediments underlying levee fill but overlying the peat <br />of Horizon3. <br />Horizon 3 is a layer of black, highly compressible peat. The peat <br />varies from fibrous to highly decayed organic matter and is intermixed with <br />varying amounts of silt and clay. The top of the peat layer in its natural <br />state usually occurs below or near sea level (Elevation 0, MSL). <br />Horizon 4 underlies the peat strata and consists primarily of <br />intermixed and interbedded sands and silts with clayey and silty zones. <br />Horizon 4 sediments are generally loose to medium dense and become denser <br />or increasingly stiff with depth. <br />Horizon 5 is the deepest soil unit in the near surface soil profile, <br />and it consists of dense sands of variable silt content interbedded with <br />zones of stiff to very stiff silts and clays. Horizon S material is <br />characterized by high relative density and shear strength and low <br />compressibility. This layer is believed to be the uppermost unit in the <br />Pleistocene sedimentary sequence, and is underlain by Tertiary sedimentary <br />marine rock formations. <br />2.4 Hydrogeologic Considerations <br />The logs of existing borings and monitoring wells installed by A.L. <br />Franks (1985) drilled and installed for Arcady Oil Company suggest the <br />occurrence of the top three soil horizons discussed above (See Appendix B). <br />The borings were less than 20 feet in depth and, therefore, generally not <br />deep enough to encounter horizons 4 and 5. No specific laboratory or field <br />2-3