ADVANCES IN UV TECHNOLOGY FOR 4-LOG VIRUS DISINFECTION

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1 ADVANCES IN UV TECHNOLOGY FOR 4-LOG VIRUS DISINFECTION KWEA/KsAWWA Joint Conference August 30, 2017

2 CURRENT REGULATIONS SURFACE WATER Surface Water Treatment Rule (1989) states 4-log virus treatment required for all surface water systems Filters might be granted only partial virus treatment UV or chlorine still required Chlorine??? Concerns about DBPs Footprint Safety and Convenience

3 CURRENT REGULATIONS GROUNDWATER Groundwater Rule (2006) GW providers must carry out triggered source water monitoring OR treat 4-log virus If TSM samples are positive for fecal indicators then treatment needed Easier to simply install treatment? GW systems can be more space constrained compared to SW systems

4 GROUNDWATER DISINFECTION Environmental Health Perspectives, September, 2012 Demonstrated epidemiological evidence that untreated bore water can lead to gastrointestinal illness in end-users Positive correlation between exposure to viruses and environmental events (i.e. rain) Increasing concerns that GW supplies are exposed to pathogens

5 WHAT IS UV LIGHT? Ultraviolet (UV) light is invisible to the human eye UV is comprised of electromagnetic radiation of wavelengths ranging from 10 nm to 400 nanometers (nm) UVA = nm UVB = nm UVC = nm 200 nm to 280 nm are germicidal

6 HOW DOES UV DISINFECT? UV light penetrates the cell wall The UV energy permanently alters the DNA structure of the microorganism Cell Wall The microorganism is inactivated and unable to reproduce or infect DNA Nucleic Acid

7 UV DISINFECTION MECHANISM A C G T A A C A T G C A T T G T G C DNA Double Strand UV (254 nm) DNA A C G T A A C A T G C A T T G T G C Dimerization of Thymine Nucleotides Dimer

8 TYPICAL UV INSTALLATIONS SURFACE WATER Surface Water Source Lake, River Coagulation Sedimentation Chemical Disinfection Filtration Storage Distribution

9 TYPICAL UV INSTALLATIONS GROUNDWATER Ground water Source Well Storage Storage Chemical Chemical Disinfection Disinfection Distribution

10 UV GUIDANCE USEPA Ultraviolet Disinfection Guidance Manual (2006) provides the necessary guidance for UV dose requirements, system validation, implementation and monitoring.

11 UV GUIDANCE Stringent UV dose requirements to treat viruses compared to other commonly targets pathogens

12 CASE STUDIES FOR APPLYING UV FOR VIRUS TREATMENT

13 SCENARIO #1 COMPLETE 4-LOG VIRUS TREATMENT WITH ONE UV SYSTEM 4-Log Virus

14 HALL ROAD, PA INSTALLATION BACKGROUND Groundwater extraction 1,080 gpm Design Flow Operated by Aqua Pennsylvania (Aqua PA) In 2009 PA State Regulators passed legislation mandating ALL groundwater providers install 4-Log virus inactivation Avoids TSM

15 HALL ROAD UV INSTALLATION OPTION #1 IMPROVE CHLORINE TREATMENT Chlorine is an effective method for the disinfection of virus BUT This often requires increasing contact time (CT) Increasing CT involves installing/expanding pipeline Can significantly increase plant footprint

16 HALL ROAD UV INSTALLATION OPTION #2 UV DISINFECTION Disinfection is instantaneous No extensive CT required Minimal additional piping required Lower capital expense Much smaller footprint No risk of DBP formation Two (2) TrojanUVSwift SC units installed

17 HALL ROAD UV INSTALLATION FOOTPRINT COMPARISON 100 Added Volumetric Footprint (m 3 ) Chemical Disinfection 3 UV Disinfection Chlorine Disinfection 430 feet of 36 pipe required to increase CT for 4-Log virus treatment UV Disinfection 2 UV reactors plus control panels

18 VALIDATING A DOSE OF 186 mj/cm 2 UV systems are validated by third-party entities using surrogate (non-pathogenic) challenge organisms Traditional surrogate organisms like MS2-Phage and T1-Phage cannot be used to measure doses of >200 mj/cm2 Would need to detect 10,000,000,000 fewer MS2 counts Validation to high doses is possible with HIGH-RESISTANCE SURROGATES Higher resistance means fewer counts would equal a dose of >200 mj/cm 2

19 DISINFECTION APPROACHES BEFORE Adenovirus Chlorine Disinfection UV Dose (mj/cm 2 ) Dual Protection E.coli Rotavirus Poliovirus Hepatitus A Streptococcus Giardia Legionella Chlorine CT UV Disinfection Crypto

20 DISINFECTION APPROACHES AFTER >186 mj/cm2 Adenovirus UV Dose (mj/cm 2 ) Rotavirus UV Disinfection Poliovirus Hepatitus A Giardia Crypto E.coli Streptococcus Legionella Chlorine CT

21 SCENARIO #2 PARTIAL VIRUS CREDIT THROUGH ONE UV SYSTEM 1-Log to 2-Log Virus

22 PARTIAL VIRUS CREDITS Many currently used UV systems are not validated with high resistance surrogates But they are not needed if only partial virus credit (~2-Log) required Virus credits are still possible with MS2-Phage validated systems D VAL > 100 mj/cm 2 possible SW and GW systems needing <4-Log virus credit (e.g. partial credit through filtration) can supplement treatment with UV to achieve full 4-log virus credit

23 BISTONE, TX UV INSTALLATION BACKGROUND Desire to reduce use of chlorine/chloramine resulted in limited CT UV considered a simple technology to make up 2-Log treatment of virus. 30-inch medium pressure UV systems installed Validated dose of 100 mj/cm 2 achieved with MS2-Phage validation

24 ACTION SPECTRUM BIAS ASCF accounts for unreliable validated performance from <240 nm. MP systems validated with MS2 Phage have very low ASCF requirements (~5% increase in dose) Water Research Foundation, 2015 MP systems validated with adenovirus (no surrogate) can be susceptible to VERY HIGH ASCF requirements

25 SCENARIO # 3 4-LOG VIRUS CREDIT THROUGH >1 SYSTEM INSTALLED IN SERIES 2-Log Virus 2-Log Virus

26 WAPPINGER S FALLS, NY Design Flow: 700 gpm Design UVT: 90% 2 Trains of 2 TrojanUVSwift 4L12 Medium- Pressure Units in Series Each unit delivers a DVAL of 100 mj/cm 2 based on MS2 validation

27 WAPPINGER S FALLS Dose additivity is accepted and employed globally, especially in wastewater treatment Installing UV reactors in series is recognized by the UVDGM Maintaining efficient hydraulics is recommended 3 pipe diameter spacing between reactors connected in series

28 SUMMARY UV emerging as mainstream option for virus treatment at drinking water plants Chemical-free treatment avoids concerns associated with byproducts and safety Several approached to using UV for virus treatment 4-Log through a single reactor 4-Log through multiple reactors connected in series <4-Log virus inactivation to complement other treatment technologies Highly resistant surrogates can be used to demonstrate high doses > 200 mj/cm 2

29 SUMMARY MS2 validations are still highly applicable to demonstrate virus treatment up to approximately 2-Log MS2 (and other surrogates) are effective for minimizing ASCF in medium-pressure UV systems Currently there are 7 states and provinces which have approved the use of UV for virus treatment Additional benefits of UV technology include but are not limited to reduced DBPs and improved safety

30 REFERENCES 1. Borchardt, M.A., Spencer, S.K., Kieker Jr., B.A., Lambertini, E.L. and Loge, F.J Viruses in Nondisinfected Drinking Water from Municipal Wells and Community Incidence of Acute Gastrointestinal Illness. Environmental Health Perspectives, 120:9, Malley Jr., J.P UV Inactivation of Viruses using Sequential Disinfection from Two UV Reactors in Series. 3. Water Research Foundation (2015). Guidance for Implementing Action Spectra Correction With Medium Pressure UV Disinfection. Denver: Water Research Foundation, pp. 2-7.

31 THANK YOU Scott Bindner Market Analyst TrojanTechnologies x 2253 sbindner@trojanuv.com