Upgrading and Renewing a 20 Year Old 40 MGD Nanofiltration Plant

Upgrading and Renewing a 20-Year-Old MGD Nanofiltration Plant Rick Chamness and Justin Barrington, P.E. Introduction Background Continuing NF Process Monitoring and Optimization Ten-Year WTP Upgrades Program Pilot Testing and Membrane Element Replacement Lessons-Learned and Conclusion Boca Raton, Florida Water Demands 36. MGD ADD 43. MGD MDD Glades Road Water Treatment Plant Biscayne Aquifer Supply MGD Design Capacity MGD Lime Softening MGD Nanofiltration Blend NF:LS ~ 2:1 MGD Nanofiltration Facility History 1999 2005 2015 Design Development Construction Completion Pilot Unit Pilot Testing Largest Operating NF Membrane Element Facility in the World Replacement Wellfield Rehabilitation No Chemical No Chemical Pretreatment Pretreatment Continuing NF Process Monitoring and Optimization Quarterly Basis since 2008 Review of WTP, Membrane Unit, and Raw Water Performance Data Meetings with Consultant and Membrane Element Manufacturer Ten-year Water Treatment Plant Upgrades Program Membrane Softening Process Renovation Needs Study Multi-Media Pressure Filter System 2005 2016 2024 Final Completion Upgrade and System Expansion Start-up Refurbishment Two New Dual-Cell Four Dual-Cell Manufacturer Inspection Filter Vessels Filter Vessels As-needed Repair and Decreased Loading Replacement of Internals Rate Nanofiltration Units Existing System Ten Primary Units Two Concentrator Units Two-Stage Third-Stage or Primary 3. MGD Capacity 2005 Membrane Elements Improvements (Ongoing Project) ARV and A/V Breaker Valve Replacement Valve Actuator Replacement Valve Inspection and Rebuilding Permeate Flush Isolation Valve Feed Piping Leakage Indicator Membrane Cleaning System Existing System Two Separate Clean-in-Place Systems Two Cleaning Solution Tanks Cleaning Pump 1-Micron Cartridge Filter Improvements (Potential Modifications) Cartridge Filter Replacement Inspection and As-needed Repairs to Process Piping Replacement of above-floor PVC Process Piping with Stainless Steel Piping Permeate Flush System Existing System 2, Gallon Storage Tank Permeate Flush Pump Automatically Flushes each NF Unit as Part of Shut-Down Sequence Permeate has Lower pH than Feed Water Improvements (Potential Modifications) Replacement of above-floor PVC Process Piping with Stainless Steel Piping Modifications to Tank Fill Piping to Utilize: Degasified Permeate High pH/Low TDS Permeate (Concentrator Units) Odor Control System Existing System Two Counter-Current Towers (Two Systems Total) Chemical Feed Systems and Recirculation Pumps Vessel Shells and Ductwork in Excellent Condition Improvements (Ongoing Project) Replacement of Recirculation Pump System, associated chemical piping and equipment. Pilot Testing and Membrane Element Replacement (Upcoming Project) Existing Membranes (~9 years old) Frequent Cleanings Cleaning Solutions Pilot Testing Cartridge Filter Elements Membrane Elements Routine Replacement (10 years) Lessons-Learned Continuous NF Process Monitoring Online Pilot Testing Raw Water Wellfield Monitoring Hydrogen Sulfide Mitigation Lessons-Learned Cont. NF Unit Feed Valve Leak Indicators Automatic Permeate Flush Permeate Flush Water Quality Future Proofing McCafferty Brinson Consulting, LLC Rick Chamness Andrew H.