To Replace or Not to Replace?, That is the Question

Do we really need to We really could replace those use those fund membranes now??? elsewhere…. Background-Tarpon Springs RO Facility Membranes Installed in April 2015 Facility Placed in Full Time Operation September 2015 Membrane Elements > Years Old Fully Funded Membrane Replacement Fund 6. MGD, Three 2. MGD RO Skids Two Stage, 42: Array, Elements/Vessel Hybrid Load Dupont SW30XLE-440i & SW30ULE-400i Variable Permeate Flow and Variable Recovery (65-80%) Membrane Replacement Guidance Criteria Selected for Evaluation Increased Salt Passage Does Not Meet Finished Water Quality Goals/Regulations Cannot Produce Design Permeate Flow With Existing Pumping Equipment High Interstage Differential Pressure Not Corrected by Cleaning Irreversible Fouling Too Frequent Membrane Cleanings New Membrane Offerings With Lower Salt Passage and Lower Pressure Findings Increasing Cleaning Frequency Required to Maintain Differential Pressure Differential Pressure A Result of First Stage Fouling Normalized Permeate Production Decreasing with Time, More Pronounced Skids 1 and Increasing Salt Passage, Not Reversed by Cleanings Increased Salt Passage Trend Not Expected to Exceed Secondary Standards for Several Years New Membranes May Produce Energy Savings at Year 0, May Be Short-lived If Fouling Not Controlled Conclusions & Recommendations Membranes Can Be Used For Up To Another Years, Providing: TDS Does Not Exceed Design Value of 16,650 mg/L TDS Salt Passage Doesn’t Exceed Historical Trend Cleaning Restore Normalized Permeate Production Improve Pretreatment to Control First Stage Fouling Trend Salt Passage Increase and Replace Membranes If the Trend Line or Two Month Running Average Exceeds 1.9% Use Normalized Permeate Flow Decrease In Addition To Differential Pressure Increase to Determine Cleaning Frequency Replace Membranes If Decreasing Normalized Permeate Flow Trend Cannot Be Reversed Respondent Facility Information Location Florida – California – Capacities Ranged from 500 gpm to MGD Feed Water 57.1 % Intermediate/Deep Aquifer Groundwater 21.4 % Shallow Groundwater 21.4% Reclaimed Water Membrane Type 57.1% Brackish 42.9 % Nanofiltration Recovery 42.9 % Eighty Percent Recovery 57.1% Varied From 75 to 90% Membrane Life Expectancy How Many Years Do You Expect How Long Did Your Last Set of A Set of Membranes To Last? To Consider When Deciding To Factors Replace Your Membranes Most Important Second Most Important Increased Salt Passage/Low Rejection Irreversible Fouling/Scaling Increased Feed Pressure Membranes Damaged Membrane Age Feed or Source Water Changed Frequent Membrane Cleaning Required Newer Membranes Requiring Less Energy Lucie Ron Johnson, Treatment Manager, SMWD Mehul Patel, Executive Director of Operations, Orange County Water District Tom Knoell, Water Operations Superintendent, Water Replenishment District.