The Journey is the Reward – Lessons Learned From a Decade of Optimizing Membrane Filtration at a Traditional SWTP

The “unicorn” of simultaneous compliance and rapid deployment:  Meet the SWTR and amendments (turbidity, micro-org’s)  Keep compliance on D/DBP Rule  Produce stable, non-aggressive finished water  Deploy quickly and predictably  No major increases in dissolved metals (Fe, Mn)  Target flow = MGD (backwash flow at the biggest WTP)  Desktop comparison of treatment tech lead to trailerized membranes (combo of rapid deploy + water quality rigor) Candidates are MF and UF.  Regulator Response – Concerns: Membrane behaviors are unknown at this site Water quality varies over the operating year  Consensus and Permit Terms: Limits operation to 3-month full-scale pilot Limit membrane effluent to MGD Use UF (predictably better log-removal of micro-org’s)  Low effluent turbidity target (0. NTU)  Daily Membrane Integrity Testing (MIT)  Water quality data to be submitted to NJDEP monthly  Two (2) consecutive NTU exceedances trigger integrity test  Summary report to be submitted to NJDEP upon trial completion Four contractors: Membrane trailer supplier GC’s: civil, electrical, controls  Big Challenge: Integrating two trailer’s worth of membrane treatment into a working WTP with zero downtime tolerance  Major “Lessons Learned” Experience: Treatment Process Line Power Membrane Commissioning DPCC Compliance Membrane Fouling Control Settings – Power Dependency Membrane Fouling: Iron Sharpens Iron  NJAW Coastal North uses Aquifer Storage and Recovery (ASR) strategies to bank treated surface water in a confined aquifer stratum during periods of low demand  Supplements source water allocation and safe yield during periods of high demand  To test flexibility of membrane treatment, NJAW flowed ASR water to membranes during Summer 2015 ASR Fe was in the 1-2 mg/L range Compare to typ. 0.5 mg/L in reservoir water  2014 operating lessons had taught us to pre-feed NaOCl, to prevent biofouling. 2017 to 2023: A Showcase of Water Quality Excellence, Predictability  Daily Membrane Reports Effl uent Turbidity Performance Consistency of operation of Membrane Modules Operation expanded to multiple seasons, (Averages and Extrema, in NTU’s) rather than limited to Summer operations Across a range of seasons 0.16 0.14  Turbidity Data 0.135 0.12 0.1 NJDEP set 0. NTU limit 0.08 0.082 No recorded excursions 0.06 0.067 0.064 0.04 0.045  Membrane Integrity Testing – Consistently 0.032 0.02 0.027 0.026 0.022 achieve and/or exceed pressure hold tests, 0.012 0.014 0.011 0 correlating to microbials log-removals at or Module Module Module Module 4 beyond permit requirements Max.