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attempt to un-jam itself three times. If after the third try it is still jammed , the screen will shut down until it is manually restarted . If a conveyor fails , the set of bar screens associated with the conveyor will shut down . (3) Each conveyor will be operated 24 hours per day, 7 days per week and will have a simple "on-off' switch together with safety controls to shut the unit off in the event of a jam . A control system cannot be simpler than this design . • Ease of Operation and Maintenance — The bar screen system will be easy to operate and maintain . The self-cleaning bar screens are almost maintenance free and the other equipment is simple in design and easy to repair. • Pollution Removal Efficiency — It is very difficult to estimate the pollutant removal rates for the bar screen system. Sediment and other solids that are typically carried along the canal bottom during storm flows will deposit in the sedimentation basin and be removed daily or weekly as required , by the sediment removal pumps . Vegetation and trash will be removed by the bar screens . The scraping mechanisms on the self-cleaning bar screens travel very slow, approximately 28 inches per minute. This allows debris to accumulate on the screen before the next cleaning cycle. As debris accumulates , particles smaller than the bar screen opening will be trapped in the pile , effecting short- term removal of the smaller particles. In any event, all particles 1 /8-inch or larger will be removed with many particles smaller than 1 /8-inch being caught in the temporary mats and removed . Research indicates that in the canals , 25 percent of the total nitrogen (TN ) and 40 percent of the total phosphorus (TP) is associated with particulate matter, with the remainder being in the dissolved form . The particulate matter consists of settelable particles and plant material . Therefore, assuming that the pumped sedimentation basin and the bar screens will remove 90 percent of the TN and TP associated with particulate matter, the removal is estimated to equal 46 ,800 lbs per year TN and 11 , 500 lbs per year TP . With respect to total suspended solids (TSS), assume that the pumped sedimentation basin will remove approximately 75 percent of the TSS that a vortex treatment system would remove. Assume that a vortex system would remove 60 percent of the TSS in the canal water. Therefore, the sedimentation basin is estimated to remove 75 percent of that 60 percent, or 906 , 000 lbs per year from the Main Relief Canal . • Construction Cost — IRC estimates that the bar screen system will cost about $3.4 million . Therefore , it is clear that the bar screen system will provide the most effective use of IRC's limited construction funds . The system's simple design will be reflected in its ease of operation and maintenance. The cost savings realized by this design will allow IRC to construct other worthy stormwater pollution control projects and reduce pollution of the Indian River Lagoon . This one project provides a significant opportunity for Indian River County to make great strides in meeting the proposed TMDLs for this basin of the Indian River Lagoon and improving estuarine habitat and water quality for this segment of the Indian River Lagoon . DEP Agreement No. G0182, Attachment A- 1 , Page 4 of 12