Upgrading the City of Fort Myers Reverse Osmosis Water Treatment Plant

Upgrading City of Fort Myers RO WTP Carlos Corbala, 03/5/2024 11: AM Ryan Eck; Mark Martin; Mike McGee; Vasu Srinivas; Jason Sciandra; James DeCarolis Upgrading the City of Fort Myers Reverse Osmosis Water Treatment Plant to Service Growing Potable Water Demands and Address Increasing Raw Water Chloride Levels The City of Fort Myers owns and operates a brackish groundwater Reverse Osmosis (RO) Water Treatment Plant (WTP) with a permitted capacity of Million Gallons per Day (MGD). The existing treatment processes at the WTP include: Sand separators 5-micron cartridge filters Two-stage RO trains Degasifier system Post-treatment chemical addition Disinfection Cartridge Filters: Parker Hannifin Corporation Cartridge Filters Maximum vessel capacity 7. MGD Operating pressure 35 – 40 psi 100% FDA polypropylene material 5-micron rating 3-duty, 1-standby Membrane Feed Pumps: Goulds 3409S: 8×12-22L Pumps Horizontal split case, centrifugal 3, GPM 215 psi discharge pressure TDH 500 ft HP VFD 3-duty, 1-standby Degasifier System: 2 large duty, 2 small standby Large degasifier design flow of 6. MGD Small degasifier design flow of 2. MGD 99% Sulfide removal Jaeger 3.5” Tri-Pack packing type Water Quality Treatment Goals: The new RO membranes will allow for an increase to the bypass percentage, while still maintaining compliance with water quality goals. Expansion and Upgrades From MGD to MGD Capacity Expansion Main drivers: Increasing water demand Increase in chlorides and total dissolved solids (TDS) Aging plant equipment The WTP treatment processes require expansion and upgrades to meet current and future potable water demands with a target finished water capacity of MGD. Approach Three new 2-stage RO Replacing the existing Demolition of the 2nd-stage RO units with existing 1st-stage RO trains each with a two new RO trains with units and membrane permeate production a permeate production feed pumps and piping capacity of MGD Temporary capacity of MGD New 2-stage RO train to Completion will provide provide the City with 15 premanufactured RO units the City with MGD of MGD of firm capacity. to provide immediate new RO unit permeate capacity increase of 1 production capacity. Common Suction and Discharge Headers From MGD to MGD Capacity Expansion Implications: Common feed header pressure constraint Feed Pump setpoints Energy efficiency RO Unit Flushing and CIP batching From MGD to MGD Capacity Expansion Considerations: RO unit flushing: Feed water Non-degasified permeate Degasified permeate CIP batching: Non-degasified permeate Degasified permeate Summary Decisions Taken: Temporary RO Units New RO Trains 8, Gallon CIP Tanks Feed Water Flushing Non-degasified Permeate CIP Batching.