Potable Reuse in California Update on Research Topics Northern - PowerPoint PPT Presentation

Potable Reuse in California – Update on Research Topics Northern California WateReuse Chapter online Meeting August 28, 2020 Adam Olivieri, EOA, Inc. Brian Pecson, Trussell Tech Julie Minton, WRF 1

Potable Reuse in California – Update Research Topics — Background — Expert Panel Findings and Research Needs — Potable Reuse Regulation/Defined — Groundwater recharge & Surface Water Augmentation — Potable reuse via raw water and treated water augmentation — Update on Potable Reuse Investigations –Microbial Focus — Pant Performance and QMRA Tools — Pathogen Monitoring including SARS-CoV-2 — Monitoring outbreak concentration of pathogens 2

Expert Panel Findings on Direct Potable Reuse — CA State Expert Panel assessed DPR EXPERT PANEL FINAL REPORT feasibility — Concluded it is feasible to create DP DPR uniform regulations for DPR Evaluation of the Feasibility of Developing Uniform Water Recycling Criteria for Direct Potable Reuse — Expert Panel recommended 6 topics for d B o a r n t r o l e s C o o u r c r R e s further research W a t e S t a t e r n i a C a l i f o

SW SWB Grant 1: 5 D DPR Research h Projects Research addressing Pathogens Public Health Protection � DPR-1. Quantitative Microbial Risk Assessment* � DPR-2. Measure Pathogens in Wastewater* � DPR-3. Collecting Pathogens in Wastewater During Outbreaks Research addressing Chemicals � DPR-4. Treatment for Averaging Potential Chemical Peaks � DPR-5. Low Molecular Weight Unknown Compounds *Co-funded by Research implementation late 2018 – late 2020 Metropolitan Water District 7

Potable Reuse In California 5 5

ENVIRONMENTAL BARRIER – GWR and SWA (Reservoir Water Augmentation) • Benefits: • Attenuate chemical spikes • Robust pathogen barrier • Response time • Hand of Hygia 6

Research Related to Public Health Protection Pathogens 1 - Pathogen Monitoring 2 - Plant Reliability and Quantitative Microbial 3 - Outbreak Monitoring Risk Assessment 5 - Non-Targeted 4- Control of Source Control Analysis and Low Chemical Peaks Molecular Weight Compounds Chemicals

DPR Pathogen Conc, Risk and Treatment Pa Pathogen DPR-2: DP 2: Pathogen High Concentrations Co Mo Monitoring 10 5 Raw wastewater Pathogen Concentration Treatment Tr DP DPR-1: 1: 10-log 11-log 12-log Re Requirements 1 Im Implementation on of P of Prob obabilisti tic c Tr Treatment Tr Train Performance and Pe Drinking water QM QMRA RA Risk Ri 10 -5 Very Low

DPR -1 TWG and Research Team Technical Working Group Te Charles Haas Ch Ni Nick As Ashbolt Th Theresa Sl Slifko Br Brian Pe Pecson (c (chair) Drexel University University of Alberta Metropolitan Water Trussell Technologies District Re Research Team Da Dan Ge Gerrity Ed Edmund Se Seto UNLV University of Washington

DPR – 1 Investigation Topics — Understanding the Benchmark Curve — Impact of Raw Wastewater Pathogen Concentration — Impact of Treatment Redundancy — Impact of Treatment Variability and Failure Assumptions — Sensitivity Analysis ”So what’s this? I asked for a hammer ! A hammer! This is a crescent wrench! … Well, maybe it’s a hammer.… Damn these stone tools.” 10

Tools provide clear reproducible approach to help develop criteria 3. 3. Risk Characterization Ch on 1. Exposure Assessment 1. 2. Dose-Re 2. Response Raw Treatment Drinking water Drinking water Exposure Dose-response Risk Ri wastewater levels consumption Which D-R functions to use? How do we quantify performance? Which D-R functions to use? How do we quantify performance? Which D-R functions to use? Which D-R functions to use? What pathogens? Which D-R functions to use? What pathogens? How much water do people drink? How much water do people drink? How do we quantify performance? What pathogens? How do we quantify performance? How much water do people drink? What pathogens? Use surrogates or direct pathogen measurements? Use surrogates or direct pathogen measurements? What about molecular data? What about molecular data? How do we quantify performance? What about molecular data? What enumeration methods? How much water do people drink? What about molecular data? The TWG and Research Team will create tools to co consistently evaluate performance and risk What enumeration methods? Estimate with a distribution? Which one? Estimate with a distribution? Which one? What about molecular data? Use surrogates or direct pathogen measurements? What enumeration methods? How much water do people drink? Use surrogates or direct pathogen measurements? Estimate with a distribution? Which one? What enumeration methods? What data should we use? What data should we use? Use surrogates or direct pathogen measurements? What data sets should we use? Do we need new data? Estimate with a distribution? Which one? What data sets should we use? Do we need new data? Use a point estimate? Which one? Use a point estimate? Which one? What data sets should we use? Do we need new data? What data should we use? Estimate with a distribution? Which one? What data should we use? Use a point estimate? Which one? What data sets should we use? Do we need new data? DDW will be trained to use the tools to assist them with DPR regulatory development Should we use site-specific performance distributions? Should we use site-specific performance distributions? How do we use non-culture-based data? What data should we use? Which D-R functions to use? Use a point estimate? Which one? Ranges from the literature? How do we use non-culture-based data? Does it matter? How much does it matter? Ranges from the literature? Which D-R functions to use? Does it matter? How much does it matter? Should we use site-specific performance distributions? How do we use non-culture-based data? Use a point estimate? Which one? Should we use site-specific performance distributions? Does it matter? How much does it matter? How do we use non-culture-based data? Ranges from the literature? Ranges from the literature? Should we use site-specific performance distributions? Does it matter? How much does it matter? What about molecular data? What about molecular data? Ranges from the literature? Does it matter? How much does it matter?

Calculating the Benchmark Treatment Train Calculating the Benchmark Treatment Train 1. Exposure Assessment 1. 1. Exposure Assessment 1. 2. 2. Dose-Re 2. Dose-Re 2. Response Response Raw Treatment Drinking water Drinking water Exposure Raw Treatment Drinking water Drinking water Exposure Dose-response Dose-response Risk Risk wastewater wastewater levels levels consumption consumption 𝑈𝑝𝑚𝑓𝑠𝑏𝑐𝑚𝑓 𝐽𝑜𝑔𝑓𝑑𝑢𝑗𝑝𝑜 𝑆𝑗𝑡𝑙 = 1 − 𝐸 ! 𝑊 𝑦 10 "#$ % &'() * 𝑈𝑝𝑚𝑓𝑠𝑏𝑐𝑚𝑓 𝐽𝑜𝑔𝑓𝑑𝑢𝑗𝑝𝑜 𝑆𝑗𝑡𝑙 = 1 − 𝐸 ! 𝑊 𝑦 10 "#$ % &'() *

1.E+04 1.E+03 Distribution from Rose et al. 2004 1.E+02 1.E+01 Crypto concentration (organisms/L) 1.E+00 1.E-01 1.E-02 5 LRV at ~7 LRV at 9 LRV at 1 st median 99 th 1.E-03 percentil percentile e 1.E-04 1.E-05 1.E-06 Tolerable drinking water density of 1.7 x 10 -6 Crypto oocysts / L 1.E-07 0.01 0.1 1 5 10 20 30 50 70 80 90 95 99 99.9 99.99 Percent ≤

Tools can be used together to develop DPR criteria Treatment Requirements QMRA Performance Evaluation 12 / 10 / 10 12 / 10 / 10 1E-02 Crypto 1E-03 1E-04 Annual risk of Cryptosporidium infection 1E-05 1E-06 1E-07 1E-08 13 / 11 / 11 13 / 11 / 11 1E-09 1E-10 1E-11 Baseline risk - no failures 1E-12 1E-13 1E-14 1E-15 99.9 0.1 1 5 10 20 30 50 7080 90 95 99 99.9 Percent less than or equal to 14 / 12 / 12 14 / 12 / 12 If we shift the treatment requirements…. …what is the impact on public health?

Treatment Train Performance Daily Risk 10 -6 1 0.9 10 -7 0.8 LRV of 13 10 -8 LRV of 12 Daily Risk of Cryptosporidium Infection 0.7 LRV of 11 Probability Less Than or Equal To LRV of 10 SD Demo Data 10 -9 0.6 10 -10 0.5 SD Demo Data LRV of 13 0.4 LRV of 12 10 -11 LRV of 11 LRV of 10 Daily Risk Target 0.3 10 -12 0.2 10 -13 0.1 10 -14 0 0.01 0.1 1 5 10 20 30 50 70 80 90 95 99 99.9 99.99 6 8 10 12 14 16 18 20 Percent less than or equal to LRV

Redundancy is important when considering the impact of low probability failure events 1.E-02 1.E-03 1.E-04 1.E-05 1.E-06 Daily Risk of Cryptosporidium Infection 1.E-07 1.E-08 1.E-09 1.E-10 1.E-11 Moderate Redundancy 1.E-12 1.E-13 1.E-14 1.E-15 High Redundancy 1.E-16 1.E-17 0.01 0.1 1 5 10 20 30 50 70 80 90 95 99 99.9 99.99 Percent ≤

Investigate impact on risk by changing assumptions of different steps of QMRA 3. Risk 3. Ch Characterization on 1. 1. Exposure Assessment 2. 2. Dose-Re Response Raw Treatment Drinking water Drinking water Exposure Dose-response Risk wastewater levels consumption Moderate High Low Low Calculated Calculated Calculated (DPR-2) (Sensitivity (DPR-1) (Sensitivity Analysis) Analysis) Constant point estimate Constant point estimate Beta-Poisson vs. exponential? (1.5L) vs. distribution? vs. distribution?