Overcoming Barriers to Better Building Management for Legionella with Water Safety Plans and Other Tidbits

Transcription

1 Overcoming Barriers to Better Building Management for Legionella with Water Safety Plans and Other Tidbits Jennifer L. Clancy, Ph.D., M.S. Law, BCES ESPRI The Environmental Science, Policy & Research Institute 4012 Ridge Avenue, Philadelphia, PA Jen Cell: (802)

2 Thank you to the NAS Panel for asking practitioners to provide insight into the NAS process

3 Legionnaires Disease and me Bellevue Stratford Hotel, Philadelphia, July cases, 29 deaths from??? Legionella pneumophila identified as cause of outbreak, January 1977 Development of CYE agar, 1979 BCYE agar, 1981 U. of Vermont, College of Medicine, Dept. of Pulmonary Medicine, Jan $2 million NSF grant to study the pathology of LD Develop an animal model of LD

4 Legionnaires Disease and me Did a Ph.D. medical microbiology Late 1980s worked in environmental microbiology on LD monitoring programs and outbreak investigations. Led into legal work in building WQ cases. Worked on cases as a consultant and expert witness over the past 25+ years. My role was always after the fact, after someone was disabled or dead. Last 3-4 years, the approach in the US has moved from reactive to proactive ASHRAE updates CDC recognition of LD as #1 waterborne disease Standards development HACCP approach for building water safety plans (developer Aaron Rosenblatt) CDC Toolkit NYC regulations for cooling towers CMS Directive Excited to see the changes over 38 years

5 Questions Posed by the NAS Panel 1. Constraints to building-level controls and how ability to control Legionnaires Disease (LD) varies from building to building vary from, region to region 2. What can water utilities do better to help prevent LD? [And what can t they do?] 3. What are weaknesses in current legal framework and how can law, policy, and practice be improved in the public and private sector to prevent LD? 4. My position on verification monitoring for L. pneumophila for legal reasons? 5. Building diagnostics that use relatively simple monitoring tools

6 Issues that make building plumbing unique and can lead to WQ problems High SA to V ratio Materials Water age (LEED) Extreme temperatures Low to no disinfectant residual Bacterial regrowth High variable velocities Proximity to service lines Cross connections Aerosol exposure Report,

7 My Goal for what the Panel will Take Away It s all about the building Unique ecosystems in the building Management of LD happens at the building Drinking water suppliers have a clear role Reiterate and build partnerships between utilities and customers Need clearly defined research plans Define most urgent needs and FUND research now Meanwhile, we do know what works to manage LD in buildings Develop programs based on the federal initiatives (CDC, CMS, VA) Educate building owners Implement water management plans

8 Constraints to building-level controls and how ability to control Legionnaires Disease varies from building to building vary from, region to region

9 Hard Constraints Constraints vary building to building and even faucet to faucet; onesize-fits-all controls not an option Building to building variation You ve seen one VA hospital you ve seen one VA hospital Dr. Shantini Gamage, Dept of Veterans Affairs Influent water quality dictates best controls Disinfectant type and concentration Organic carbon Temperature (cold isn t really cold in the summer in Southern US) Uses dictate the best controls Hospitals and health care facilities Facilities with seasonal use patterns Facilities with high use by more susceptible individuals

10 Shower (S) or Tap (T) More About Buildings and Constraints Taps/faucets: diverse & numerous Table shows % Lp positive in a hospital (Marrie et al., 1992) High variability, tap-by-tap Develop your sampling strategy carefully! Counts can vary widely, even over the course of a single day (Volker et al., 2016) Plumbing can be changed, but is a constraint L. pneumophila more prevalent in older fixtures Older showerheads have higher L. pneumophila occurrence (Collins et al., 2016) New copper pipe can exert high disinfectant demand (Drexel/ESPRI/CU Boulder study, data shown later) Site % positive A T NICU T A T A T B T A S B T A S B T EMERG T

11 Building Water Systems are Diverse Components and Seldom Designed with Water Quality in Mind Very low awareness that BWS choices have water quality impacts Insufficient data on the impacts of the wide array of materials and components on water quality In a water distribution system, every building is a dead end

12 Pipe Racks Boulder, CO Philadelphia, PA

13 Pipes and Components and Water Quality Free chlorine residual in feed about 1 mg/l Water uses High use: 12 hr stagnation time Low use: 1 wk stagnation time Pipe diameters: ½ and ¾ 13

14 Pipes and Components and Water Quality, Part 2 Competing risks: DBP v. L. pneumophila High stagnation times promote DBP formation, even in cold water Trade-offs between Legionella and OPPPs control 14

15 Soft Constraints Building owners and operators differ widely in their understanding, abilities and concern regarding LD No ready training or standards for building water system (BWS) operators Science of Legionella control not yet mature Misinformation from vendors, interest groups, under-informed scientists Conceptions of liability and responsibility Sampling for Legionella and other Opportunistic Premise Plumbing Pathogens (OPPPs) No way to interpret results of a sampling campaign (no standards to benchmark against) Difficulty communicating results of sampling campaigns to stakeholders Fear of you knew you had Legionellae in your pipes, but you didn t act (enough) on it Assessing building water system Seldom done proactively (but popular following cases/outbreaks) Fear of you knew you had problems, but didn t act on them. 15

16 Primary prevention Secondary prevention Example Standards and Sampling Protocols (from Ditomasso et al., 2010) Location Monitoring program Sample Limiting value Allegheny County, PA Y Y Yearly in all healthcare facilities Periodic sampling where persons at high risk might be exposed Hot water tank: water samples Faucets and showerheads: biofilm samples 30% samples culture positive Australia N Y Investigation of an outbreak Validation of the effectiveness of decontamination UK Y Y Weekly in system where temperature & biocide levels are not being achieved Monthly, water system treated w/ biocides Outbreak investigations Faucets and showerheads: biofilm samples & water samples Water(1L): preflushing and postflushing samples at all outlets Pre- and postflushing water samples (1L) from water faucets and showerheads 10 4 CFU/L 10 3 CFU/L

17 WHO Recommendations Legionella Conc (CFU/L) 1000 > > Assessment Corrective action Next step Tier 1: Adequate control of Legionella Tier 2: Legionella present in low concentration Tier 3: Legionella present in high concentration > Tier 4: Legionella present in very high concentration None Resample within two weeks: If still > /L: sanitize/disinfect the warm water system within one week If >10000/L: move to appropriate category If 1000/L: resample within three months Resample immediately and conduct further risk assessment of drinking-water installation: If still > /L: sanitize/disinfect the warm water system immediately, take measures to prevent recurrence based on risk assessment If >100000/L: move to appropriate category Resample immediately and conduct further risk assessment of drinking-water installation: If still >100000/L: disinfect the warm water system and restrict use (i.e. ban showering) immediately, take control measures to prevent recurrence based on risk assessment If /L: move to appropriate category Resample after one year Resample within two weeks to determine if Legionella is 1000/L Resample within one week after sanitizing/ disinfection to determine if Legionella is 1000/L Check if control measures are implemented Resample within two weeks to determine if Legionella is 1000/L Check if control measures are implemented 17

18 Summary of Standards Water samples with Legionella in a building Action at between 10 3 and 10 4 CFU/L Action when > 30% of taps positive by culture Sampling from weekly to annually No clear consensus. Need science to support data development and interpretation.

19 Buildings as Consecutive DW Systems According to the SDWA, If you treat, you re in the regulated water system club States approach this requirement differently; most taking a wait and see stance Do state agencies have the wherewithal to regulate consecutive building water systems effectively? If you are a regulated system, you Must conduct total coliform rule sampling (with concurrent disinfectant residual measurement and follow-up sampling for positives) Must maintain and monitor residual at the point of entry (POE; unclear how this is defined for a BWS) Must conduct quarterly disinfection byproduct (DBP) sampling Are subject to the Lead and Copper Rule Are subject to many other regulatory and reporting requirements (certified operator) 19

20 Summary of Constraints Hard Each tap and branch is unique and has the potential to grow Legionella Control must account for diversity in materials, components, designs All systems have stagnancy Risk trade-offs Soft Operator skill set and qualifications not defined Liability concerns promote inaction No US standards for Legionella in water systems (obstacle to monitoring) Ambiguity in regulation of BWSs as consecutive systems 20

21 What can water utilities do better to help prevent LD? And what can t they do?

22 What Water Providers can do to Help Maintain Good Building Water Quality and Control Legionella Meet disinfectant residual requirements At Building POE Maintain distribution system integrity and address potential intrusion events Provide customers solid, scientific information on how to operate their water systems WRF Customer Messaging on Plumbing System Issues Other Promote water management plans

23 Measurable and Effective Chlorine in the DS Makes a Difference Frequency E. coli present Frequency E. coli present Total Chlorine Concentration (mg/l) Free Chlorine Concentration (mg/l) Six year review data Disinfectant residual concentration of E. coli positive samples Detectable and effective residual is important for control of fecal pathogens Bacteria (including Legionellae) can be present, even when residual concentration is high

24 What Water Providers Cannot Do Ensure disinfectant residual reaches taps Eliminate Legionnaires disease and other illnesses associated with organisms that can grow in plumbing systems Dictate how customers operate their plumbing systems

25 Residual at the Building Entry Point does not Mean Residual at the Point of Use Primary loss mechanisms Decay Bulk water Pipe walls Stagnant legs Water heaters Higher temperature increases decay rates Demands from sediment Long residence times Other loss mechanisms Demand from new copper pipe Nitrification Demand New organic carbon drawn into the plumbing Old carbon in the form of biofilm and cells

26 Look at 3 Case Studies All hospitals All had positive Legionella samples but no observed cases Two of 3 referred by the water utility, who got the first call Legionella issues are often not the only issue

27 Case Study 1: Discolored Water in Hospital 150,000 ft 2 facility, commissioned in 2000 Provides ambulatory services to Navy base In 2016, discolored water was reported in taps Flushing was implemented but discolored water persisted in some locations 27

28 Findings: Discolored Water and Corrosion Some iron valves have been replaced due to corrosion No discolored water in cold water Discolored water in hot water due to accumulated particles Elevated lead in some samples Turbidities up to 186 ntu 28

29 Cause of the Corrosion and Discolored Water Clark and Edwards (2016) 29

30 Metals Results Sample Location Copper (µg/l) Secondary Standard = 1000 Iron (mg/l) Secondary Standard = 0.3 Lead (µg/l) Action Level = 15 POE ND 0.15 ND Softener In 8.9 ND ND Soft Out ND ND ND Hot Utility H 150, , H2 (post clearing) H H

31 Recommendations Conduct flushing to eliminate accumulated particles Improve material compatibility (replace dissimilar metals). oflush a second time to remove any dislodged particles Develop water management plan 31

32 Case Study 2: Legionella and Corrosion in Hospital The hospital has more than 400 beds and offers clinical, surgical, and specialty services The facility is located in California and is required to have 3 days emergency water storage The storage tank currently designed for 3 days emergency supply for an existing building and two future buildings 32

33 Hospital Water Supply Supply Water with Chloramines Storage Tanks with Ozone Disinfection Softener Hospital Building 2.5 mg/l total chlorine 0.5 mg/l total chlorine 0.2 mg/l total chlorine Nondetectable residual 33

34 Causes of Disinfectant Decay in Storage Tank Nitrification Poor mixing in tank Biofilm High water age Ozone system NH 2 Cl + 3O 3 2H + + NO 3- + Cl - + 3O 2

35 Other Identified Issues Ozone system was not operational Corrosion: ovalves have been replaced frequently oauxiliary water heater in hospital replaced 3 times in 2 years odissolved copper increased through building

36 Total chlorine, mg/l Total chlorine profiles, Nov 7-9, Building 1 Building 2 Building 3 Building Water Supply Storage Tank Out (Building 1 only) Softener Out Water Heater Out (not available at Building 2) Distal Sample Point

37 Copper (mg/l) Copper profiles, Nov 7-9, Softener Out Building 1 Heater Out Building 1 Softened Cold Water (at drinking fountain) Building 1 Hot Water Return

38 Recommendations Drain and bypass emergency water storage tank until a disinfection booster system is installed in the tank mg/l total chlorine mg/l total chlorine mg/l total chlorine Good to poor residual at POUs 38

39 Recommendations Blend softened cold water with domestic cold water for domestic hot water Improve material compatibility (replace dissimilar metals) Treat water at the storage tank Develop a water management plan for the hospital

40 Lessons Learned Storage is problematic, whether in a distribution system or a building Local regulations require 3 days storage Prime opportunity for high water age, nitrification and more Storage was designed with large dead zones, poor water exchange The building context needs to be considered when treatment is selected and designed Softening also removes residual Complex treatment process such as ozone disinfection might not be practical Staff running the treatment equipment probably not as experienced and knowledgeable as staff at a treatment plant

41 Case Study 3: Legionella pneumophila Prevalence in Water Piping and Points-of-Use (POU) at Hospital 1mL tap water, nurses station Sample type Total samples collected Number positive for L. pneumophila Percent positive for L. pneumophila Cold water supply piping Hot water supply/return piping Cold sink tap POU Hot sink tap POU Blended hot/cold sink tap POU Blended hot/cold shower tap POU All point-of-use samples All samples

42 What are weaknesses in current legal framework and how can law, policy, and practice be improved to prevent LD? The public and private sectors

43 Law, Policy, Practice to prevent LD US approach has been reactive For DW, SWTR regulates Legionella using treatment technique This probably works based on studies of occurrence in source and treated water No predictor of levels in a building Monitor only if there is a problem, case of LD or outbreak Lack of reproducible and challenging methods cited as reason not to monitor Inability to meaningfully interpret monitoring data Occurrence, risk, cases of disease Result is few data and incomplete understanding of what those data mean What do I do now? Paralysis in moving forward in understanding and managing the problem We may be moving forward

44 My position on verification monitoring for L. pneumophila for legal reasons 44

45 Monitor! From proposed European Technical Guidelines HPC (i.e. colony counts at 22 C) is not directly related to Legionella or other opportunistic pathogens meeting HPC levels is not sufficiently protective against Legionella and other opportunistic pathogens Recommend a requirement for verification monitoring of Legionella with a trigger value which is intended to prompt corrective action to prevent further Legionella proliferation A value of 1000/L seems appropriate to indicate that conditions for Legionella proliferation are present in the warm water system and require management attention to control Legionella. This is not a health-based value but a screening value to trigger action to prevent further proliferation of Legionella and the associated health risk. 45

46 From European Technical Guidelines (cont.) Suggested sampling site is water at the point of use, specifically at points of aerosolization, such as a showerheads or warm water taps. Sampling protocol should aim to sample the water from the warm water plumbing system directly (and not flush the system before sampling), as this water is most prone to harbour Legionella. Enumeration of Legionella should be according to standardized culture methods (i.e. EN ISO 11731:2017) 46

47 Building diagnostics that use relatively simple monitoring tools No substitution for boots on the ground

48 Keys to Building Water System Assessments Preparation Understand the system Use that understanding to inform a sampling plan Basic measurements First draw and flushed residual concentration Temperature Temperature of the cold water (if it s warm, indication that mixing valves are not right) Time for cold and hot to reach a steady temperature (indicator of pipe run length and mixing) Temperature of hot water (critical control) Observations Water features? Flow patterns through water heaters Backflow prevention configuration and testing

49 Other Useful (and not too difficult) Measurements Heterotrophic plate count (HPC) Iron, copper and other metals Nitrite, nitrate and ammonia (for chloraminated systems)

50 How can we prevent Legionnaires Disease? We know how to control Legionella in building water systems Keep the cold water cold (below 20 C, 68 F) and the hot water hot (60 C, 140 F) watch out for scalding Keep the water moving, avoid stagnation Maintain plumbing fixtures, clean hot water tanks Understand the building water system and how to manage it effectively (HACCP plans) Identify hazards, monitor critical control points, verify that the metrics you ve established to maintain good WQ are being met, and fix the system when problems arise May require additional water treatment to maintain WQ Manage building water quality

51 HACCP Overview Hazard Analysis and Critical Control Point (HACCP) HACCP is a systematic, flexible, science-based methodology designed to prevent hazards from harming people. Used in many industries Munitions Food Drinking water (WHO guidelines used in Europe, Australia) Building plumbing 51

52 Focus for Managing Building WQ Sediment Temperature water Age disinfectantresidual * Gordon & Rosenblatt Keep the cold water cold and the hot water hot, keep the water moving and the system clean

53 New Water Paradigm New Paradigm A set of beliefs that replaces another set which is believed no longer to apply Water that is safe to drink may not be safe to breathe The water that the utility sends to its customers is often not what is found at the tap in the building Need to move away from source to tap claims from utilities because utilities test on their side of the meter and do not have any control once water passes the meter. Water suppliers do not know what WQ their customers experience at the tap. Water users know even less about the WQ Source to tap needs to include the building and its effects on WQ

54 Learning from Crypto Responding to Cryptosporidium took Millions of dollars of research into treatment technologies, microbial methods, dose-response and more Regulations ESWTR LT ESWTR LT2 Now Crypto has been replaced by Legionella as the most common waterborne disease 1912 Tyzzer describes Cryptosporidium muris oocysts in mice 1984 to Waterborne outbreaks Braun Station, TX 1987 Carrollton, GA 1989 Swindon Oxford, UK 1993 Milwaukee, WI ASTM Method P-229 for Giardia & Cryptosporidium 1996 ICR Method for national monitoring 1998 Method 1622/ Clancy et al. - UV dose19 mj/cm 2 provided >4 log inactivation 2000 Clancy et al. - UV doses 4 mj/cm 2 provided >4 log inactivation 2003 EPA UV Guidance Manual for SW treatment 2006 Long Term 2 Surface Water Treatment Rule source water monitoring for Crypto 2013 Baker City, OR outbreak -OOPS! 2018 Crypto is recreational water pathogen 54

55 Legionella is a building water problem and managing it will take hand-to-hand combat It s a building water problem (putting this discussion to bed) Building water system influent water is not sterile and seeds building water systems with low numbers of OPPPs. How utilities can contribute to Legionella control How they can t Residual in the feed water doesn t mean residual in a building. Even more so for Dead legs and stagnant pipes (illustrated with data from EPA project) Nitrified building water systems Biofilms Organisms hiding in amoebae Epi studies and investigations routinely show high occurrence and abundance of Legionella in fixtures, despite high building water influent residual concentration (particularly for free chlorine)

56 Legionella is a building water problem and managing it will take hand-to-hand combat Legionella control requires hand-to-hand combat Every faucet is a unique ecosystem; every building is a unique assemblage of plumbing Every building is a dead end Before a big-foot intervention (e.g., boosting disinfectant), know your system Building water system operators are the ground troops. They need guidance, training and support. Secondary disinfection is only one strategy. Also consider using temperature, flushing, redesign

57 How we can promote Legionella control a safe breathing water act (SBWA)? What the NAS panel can do Advance productive research and debunk counterproductive claims Develop realistic criteria for assessing building water quality What should trigger levels for action In the absence of criteria and guidance, building operators don t want to sample How much disinfectant is enough? Managing multiple risks Legionella, NTM, DBPs, corrosion No residual is required at 60ºC Promote management of building WQ at the building level

58 How we can promote Legionella control a safe breathing water act (SBWA)? What might a SBWA look like? EU Directive as a starting point Clearly designates building operators/owners as responsible parties Applies only to the most at-risk facilities (health care facilities and others) Requires monitoring for Legionella (the end of burying heads in the sand) How the SDWA might be modified to contribute Surveillance for Legionella in distribution systems Uncouple buildings from consecutive system requirements

59 Thank You Questions