Lake Jesup Hydraulic Dredging Feasibility Study

Seminole County, Florida

Project Description/Services

Lake Jesup is a 23 square mile lake located in central Seminole County. The lake receives drainage from 13 basins within its defined watershed. Lake Jesup is hydraulically connected to the St. Johns River on its northeastern shore. Years of secondary wastewater treatment effluent discharge, agricultural development, and urbanization of the watershed have caused water quality degradation, accumulation of high organic flocculent sediment and the decline of the lake’s sport fishery. The Friends of Lake Jesup, working with the District, were mandated by the Florida Legislature to collect data and conduct studies and demonstration projects in an effort to produce a lake restoration and management plan for the lake. Parsons Brinckerhoff (PB) was retained by the Florida Fish and Wildlife Conservation commission to provide engineering services for sediment removal from the Lake. Parsons Brinckerhoff subcontracted the sediment sampling and testing to Madrid Engineering Group, Inc.

Because of the loose, organic flocculent nature of the sediment up to four feet thick, part of the research challenge was development of a custom-designed piston tube sampler. This was very important as representative samples were critical to the project. The effort involved collection of core samples at 30 locations and bulk samples at an additional 5 sites. Bulk samples were sent to the University of Florida for centrifuge testing.

MEG’s Laboratory Testing Services included the following tests, complete in accordance with ASTM standards: Soil description/classification, Moisture Content, Percent passing #40 Sieve, Percent passing #200 sieve, Gradation, Hydrometer, Atterberg Limits (Plasticity), Carbonate Content, Specific Gravity, and Organic Content.