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A TRUE COPY ,ERTIFICATION ON LAST PAGE J,R. SMITH, CLERK ATTACHMENT A GRANT WORK PLAN Project Title: Egret Marsh Stormwater Park Harvest Rake Replacement Project Location: 7295 4TH Street, Vero Beach, Indian River County, Florida 32968. Egret Marsh Stormwater Park treats water contributed by a 9,000 -acre agricultural drainage basin, a part of the approximately 50,000 acre Indian River Farms Water Control District, which discharges into the Indian River Lagoon. The Hydrologic Unit Code for the Indian River Lagoon is 03080203. Project Background: This project will replace the existing algae Harvest Rake at Egret Marsh Stormwater Park (Egret Marsh). Egret Marsh is a regional stormwater treatment facility that uses algae to remove dissolved nitrogen and phosphorus from water in the Indian River Farms Water Control District's (IRFWCD) Lateral D Canal, serving an approximate 9,000 acre watershed that discharges into the Indian River Lagoon. Periodically, algae growing on Egret Marsh's flow way must be harvested to remove captured nutrients from the system and to facilitate growth of new algae for further nutrient uptake. The harvested algae is collected by the Harvest Rake and deposited onto a concrete pad for further processing. Since the original Harvest Rake was installed, the manufacturer, Duperon Corporation, has developed a new Harvest Rake design based on recommendations from County staff's experienced with the original design. The original Harvest Rake is very prone to clogging due to its rotation - it rotates against the algae flow into it rather than with it. Because of resultant algae wrapping and clogging, significant staff time is required to babysit the Harvest Rake during harvest events. The rake frequently becomes clogged and when this occurs, significant amounts of algae bypass the Harvest Water Basin and flow into the Polishing Pond System. The cumulative Polishing Pond volume is slowly being compromised by the unnecessary algal flow into it. Duperon's new Harvest Rake design works with, not against the flow of algae into it, and the new design is expected to significantly reduce the possibility of clogging. This means that nearly all algae bypass issues will be eliminated, which will allow the Polishing Ponds to function as intended for a much longer period and also improve the wildlife habitat potential in and around the ponds due to a lowered pollutant load to them. Because algal removal rates will increase during harvest events with the implementation of the new Harvest Rake design, the Indian River Lagoon (IRL) will ultimately benefit since all water treated at Egret Marsh flows into the IRL. Project Description: The new Harvest Rake will replace an existing Harvest Rake that to collects harvested algae from Egret Marsh Stormwater Park's algal turf scrubber. The existing Harvest Rake will be removed from the harvest tank by a large crane and the new Harvest Rake will be installed in the same location using the same crane. The new Harvest Rake will be operated using the existing control system. TASK 1: Procurement of new Harvest Rake by Indian River County. Deliverable: Color photograph(s) of the Harvest Rake upon delivery. Timeline for Completion: 6 months from the date the County orders the new Harvest Rake from Duperon Corporation. Equipment Cost: $175,000 (DEP Funding) Performance Standard: The Department's Grant Manager will review the photograph(s) to ensure the Harvest Rake was purchased and received. Revised 6/13 DEP Agreement S0733, Attachment A, Page 1 of 1