Evaluation of Risk Reduction Principles to Direct Potable Reuse

Transcription

1 Evaluation of Risk Reduction Principles to Direct Potable Reuse WateReuse Research Association Webinar November 14, 2013 Andy Salveson, P.E. Erin Mackey, Ph.D., P.E.

2 Acknowledgements Sponsor. o WateReuse Research Foundation. Additional Funding. o o City of Ventura, California. City of San Diego, California. o City of Escondido, California. In-kind Participation. o o o o o El Paso. Oxnard. OCWD. Santa Clara Valley Water District. West Basin.

3 Acknowledgements Project Team Members Vincent Roquebert, Carollo Engineers, Inc. Graham Juby, Carollo Engineers, Inc. Dave Smith, WateReuse California Michael Flynn, NASA Matt Salveson, CSU Sacramento Dawn Guendert, GHD Project Advisory Committee Brian Bernados, CDPH Richard Sakaji, EBMUD Joe Cotruvo, Consultant James Crook, Consultant

4 SB 918 & CA s DPR Initiative Cloudcroft CRMWD Direct Potable Reuse The Time is Now

5 Better WRRF Treatment WRRF Risk & Analysis WRRF Improved 11-01, 11-10, Monitoring & WRRF Public & Outreach No Enviromental WRRF & Buffer? Direct Potable Reuse The Time is Now How Do We CA DPR Pay for Initiative!!! This???

6 Project Goal A critical initial evaluation of DPR, including treatment, monitoring, and operation.

7 Reminder - What Is DPR? Direct potable reuse is: o o Planned introduction of recycled water either directly into a public water system or into a raw water supply immediately upstream of a WTP. I.e., no environmental buffer.

8 Reminder - What Is DPR? Direct potable reuse is: o o Planned introduction of recycled water either directly into a public water system or into a raw water supply immediately upstream of a WTP. I.e., no environmental buffer.

9 Reminder - What Is DPR? Direct potable reuse is: o o Planned introduction of recycled water either directly into a public water system or into a raw water supply immediately upstream of a WTP. I.e., no environmental buffer.

10 Step 1 FAILURE ANALYSIS

11 Pre-Treatment Diurnal Flow EQ/storage MF RO UV/H 2 O 2 Secondary Effluent Concentrate Treatment Treated Water Storage Fully Advanced Treatment = RO + AOP

12 Process Errors Process upsets can throw off subsequent processes. Process failures allow undertreated water to pass to the next process. Monitoring failures can allow undertreated water to pass through. Multiple failures can lead to a Perfect Storm.

13 Human Error Potential Errors Failure to follow protocols. Mistakes. Operator doesn t know what to do.

14 Step 2 LEARN FROM OTHERS

15 Lessons Learned

16 Lessons Learned Control potential failure points relative to their risk. Look for opportunities to make things simpler &/or less tightly coupled. Monitoring is key. Monitoring is not everything. For personnel: o o Training, training, training. SOPs for critical failure events.

17 Lessons Learned Control potential failure points relative to their risk. Look for opportunities to make things simpler &/or less tightly coupled. Monitoring is key. Monitoring is not everything. For personnel: o o Training, training, training. SOPs for critical failure events.

18 Lessons Learned Control potential failure points relative to their risk. Look for opportunities to make things simpler &/or less tightly coupled. Monitoring is key. Monitoring is not everything. For personnel: o o Training, training, training. SOPs for critical failure events.

19 Lessons Learned Control potential failure points relative to their risk. Look for opportunities to make things simpler &/or less tightly coupled. Monitoring is key. Monitoring is not everything. For personnel: o o Training, training, training. SOPs for critical failure events.

20 Lessons Learned Control potential failure points relative to their risk. Look for opportunities to make things simpler &/or less tightly coupled. Monitoring is key. Monitoring is not everything. For personnel: o o Training, training, training. SOPs for critical failure events.

21 Example Application Issues qpcr Broad spectrum Time and cost pathogens Light Scatter Detects microbial activity Sufficiently sensitive? Biosensors Optical Spectroscopy Anti-body and DNA based systems Correlates particle size to pathogens In development, time and cost Cannot differentiate microbes DPR Depends Upon Improved Monitoring

22 Example Application Issues qpcr Broad spectrum Time and cost pathogens Light Scatter Detects microbial activity Sufficiently sensitive? Biosensors Optical Spectroscopy Anti-body and DNA based systems Correlates particle size to pathogens In development, time and cost Cannot differentiate microbes may be best to focus upon online monitoring of individual process performance DPR Depends Upon Improved Monitoring

23 Potential Monitoring Approaches RO Permeate. Fluorescence-based monitoring Potentially up to 6-log continuous performance verification. qpcr/rt-qpcr Can detect 1 copy of DNA but needs enrichment step. 12-hr storage, which allows: ATP testing Protein analysis, could indicate RO process failure. Bench-top but instantaneous. Rapid response microbiological viability. Disposal of flow if needed.

24 How Do We Reduce Human Error? Checklists save lives Aviation Emergency Response Plans Medicine E.g., Handwashing in hospitals (Pronovst, 2008): Death rates dropped almost in half. Serious complications dropped by more than 1/3. Sources: Atul Gawande, The Checklist, The New Yorker, 12/10/07; Maia Szalavits, A Simple Surgery Checklist Saves Lives, Time, 1/14/09.

25 Human Error Potential Hazards Failure to follow protocols. Mistakes. Control Options More training than for typical IPR applications. Exams? Standards? Detailed contingency protocols. For each high-priority contingency Routine drilling. Checklists, checklists, checklists.

26 NDMA pesticides Triclosan Ethynyl estradiol flame retardants surfactants Bisphenol-a Chronic Risks Are Important

27 NDMA pesticides Triclosan Ethynyl estradiol flame retardants surfactants Bisphenol-a Critical Risks Drive Process Management

28 NDMA pesticides Triclosan Ethynyl estradiol flame retardants surfactants Bisphenol-a Critical Risks Drive Process Management

29 Step 3 DESCRIBE A RISK ASSESSMENT APPROACH

30 Risk Management Management can involve: Transferring the risk. Avoiding the risk. Reducing the negative effect or probability of the risk. Accepting some or all of the potential or actual consequences of a particular risk.

31 Sequential Risk Analysis Characterize source water Characterize goal(s) - global Set critical limits global Set unit goal(s) & critical limits Conduct Hazard Analysis ID Control Measures or Process Modification(s) For each unit & process as a whole Verify approach Codify design & O&M plans

32 Step 4 DEVELOP DPR SCENARIOS

33 Case Study 1 Ventura, CA

34 Treatment Goals 12-log enteric virus reduction. 10-log Giardia cyst reduction. 10-log Cryptosporidium oocyst reduction. Log Credit Crypto Giardia Virus 2 o Treatment UF RO Chlorine/Storage UV/ H 2 O Total

35 Ventura Vital Stats 8 MGD 2⁰ effluent WWTP UF/MF RO Eq. Basin UV/ H 2 O MGD finished water To Distribution Storage x3 FAT+

36 Storage Provides a Buffer

37 Ventura Case Study - General Overview Potable Reuse Options IPR through groundwater injection. DPR to different locations. Continued use of existing infrastructure.

38 Option 1 Savings: 1.8 MGD Ventura River 4 MGD Mound GW Basin 5.8 MGD FAT at VWRF, Pumped 5.3 miles to Casitas #2

39 Option 2 Savings: 1.8 MGD Ventura River 4 MGD Mound GW Basin 5.8 MGD FAT at VWRF Pumped 6 miles to BTP

40 Option 3 Savings: 1.8 MGD Ventura River 4 MGD Mound GW Basin 5.8 MGD FAT at VWRF Pumped 9.3 miles to AWTP

41 Costs Ventura Options Total Construction Cost Annual O&M Annual Cost ($/AFY) Annual Cost ($/ 1,000 gal) Casitas #2 DPR $56.3M $2.6M $910 $2.80 Bailey TP DPR $57.1M $2.6M $910 $2.80 Ave. WTP DPR $62.6M $2.7M $970 $3.00 Bailey IPR $70.0M $2.9M $1,000 $3.10 Does not include credit for reduced treatment costs at WTP. Permitting and outreach efforts associated with DPR not included. Brine disposal assumed not a significant cost sector.

42 Case Study 2 Escondido, CA

43 Escondido Plan View mi, 20 force main. - Brine line back down to HARRF to outfall.

44 Treatment Goals 12-log enteric virus reduction. 10-log Giardia cyst reduction. 10-log Cryptosporidium oocyst reduction. Log Credit Crypto Giardia Virus 2⁰ Treatment UF RO Chlorine/Storage UV/ H 2 O Total

45 Escondido Alternative 1 13 MGD WWTP Effluent HARRF 9 MGD Summer 5.9 MGD Winter 7 MGD Winter 4 MGD Summer Concentrate to outfall Recycled Water Use FAT+ Dixon Lake To WTP Effluent 5 MGD Winter 2.9 MGD Summer UF/ MF RO EQ UV/ H 2 O 2 FAT+ Storage x3

46 Escondido Alternative 2 18 MGD WWTP Effluent HAARF 9 MGD Summer 12 MGD Winter 9 MGD Summer 5.9 MGD Winter Concentrate to outfall Recycled Water Use FAT+ Dixon Lake To WTP Effluent 8.6 MGD Winter 6.5 MGD Summer UF/ MF RO EQ UV/ H 2 O 2 FAT+ Storage x3

47 Costs Escondido Options Total Construction Cost Annual O&M Annual Cost ($/AFY) Annual Cost ($/1,000 gal) Alt. 1a $73.8M $2.3M $1,200 $3.70 Cap. & O&M $ for 5.6 mgd. Alt. 1b $82.6M $2.4M $1,300 $4.00 Cap. $ for 8.6 mgd inf. (5.6 mgd process), O&M for 5 mgd. Alt. 2 $18.1M ($91.9M) $4.0M $1,100 $3.40 Cap. $ to add 3.6 mgd capacity, O&M for 8.6 mgd product. Does not include credit for reduced treatment costs at WTP. Brine disposal cost assumed not significant. Permitting and outreach efforts associated with DPR not included.

48 Case Study 3 - El Paso, TX

49 Treatment Goals 12-log enteric virus reduction. 10-log Giardia cyst reduction. 10-log Cryptosporidium oocyst reduction. Log Credit Crypto Giardia Virus 2 o Treatment Denit. Filters MF RO UV/ H 2 O Treatment at WTP Total

50 El Paso Full FAT Blending with dewatering wells (5 mgd) Q = 11.1 mgd RBWWTP De-N MF RO UV/ H 2 O 2 EQ Basin Q = 1.1 mgd Q = 13.0 mgd Q = 2.0 mgd To Concentrate Disposal JRWTF To Distribution

51 El Paso Non-FAT Treatment Q = 11.1 mgd Q = 0.8 mgd To Concentrate Disposal Q = 3.9 mgd RO Q = 3.1 mgd RBWWTP De-N MF O 3 Biofilter UV/ H 2 O 2 Q = 1.1 mgd Q = 14.2 mgd EQ Basin Q = 9.2 mgd JRWTF To Distribution Blending with onsite wells (5 mgd)

52 Unlike most places, the WTP and WWTP are close together.

53 Costs El Paso Options Treatment Alternative Total Construction Cost Annual O&M Cost Annual Cost ($/AF) Annual Cost ($/1,000 gal) Alt. 1 $83.2M $6.0M $1,400 $4.16 Alt. 2 $94.2M $4.5M $1,100 $3.32 Alt 1 DWI (if needed) $17.3M $100,000 $100 $0.20 Alt 2 DWI (if needed) $6.3M $40,000 $60 $0.08

54 Conclusions Evaluating Risk Risk o Focus on eliminating acute risk due to treatment failures. Design & Operation o Other process trains besides FAT should be considered. o Focus on the goal and not specific processes. Monitoring o Push to develop better monitoring tools. Human Element o Cost o Need motivation, training, and focus. Driven by treatment train, P&P, & storage.

55 Better Treatment Improved Monitoring Risk Analysis Public Outreach No Enviromental Buffer Comments and Questions to: