Managing Water Quality to Reduce the Risk of Exposure to

Legionella and Other Opportunistic Pathogens

Shawn P. McElmurry, PhD, PE

Associate Professor

Department Civil & Environmental Engineering

Wayne State University

With contributions from:

Dr. Nancy Love, PhD, PE, BCEE

Borchardt and Glysson Collegiate Professor

Department of Civil and Environmental Engineering,

University of Michigan

Design Life:

Bridge: 50 yrs

Federal Highway System signed into law in 1956

Design Life:

Basins: 30 yrsDeep pipes: 50 yrs

Clean Water Act signed into law in 1972Safe Drinking Water Act signed into law in 1974

http://www.foxbusiness.com/features/2016/01/28/america-s-water-infrastructure-is-in-need-major-overhaul.html

From: Nancy Love (UM)

Walton (2016)

Sources: CDC Morbidity and Mortality Weekly Report (MMWR) Surveillance Summaries: 1995-1996 [1], 1997-1998 [2], 1999-2000 [3], 2001-2002 [4], 2003-2004 [5], 2005-2006 [6], 2007-2008 [7], 2009-2010 , 2011-2012.

Credit: Audrey Zarb

https://www.cdc.gov/healthywater/surveillance/index.html

*One of the WBDOs had two predominant illnesses: acute respiratory illness and gastroenteritis. † All acute respiratory illness was attributed to Legionella spp. § All dermatitis was attributed to chemicals/toxins. ¶ Including one Legionella spp. outbreak that involved both acute respiratory and gastrointestinal illnesses. ** Each outbreak involves more than one etiologic agent.

Waterborne-disease outbreaks associated with drinking water, by illness and etiologyUnited States: 2003-2004

*All acute respiratory illness was attributed to Legionella spp.† The outbreak with multiple etiologies involved bacterial and parasitic agents

Waterborne-disease outbreaks associated with drinking water, by illness and etiologyUnited States: 2011-2012

Regulated monitoring only targets gastrointestinal indicators, not respiratory indicators

Reported cases of legionellosis in Michigan

https://www.cdc.gov/legionella/images/national-incidence.jpg

Legionnaires’ Disease (i.e. Legionellosis) Cases Increasing Nationally and in Michigan

Who is most at Risk for Legionnaires’ Disease?

• Anyone who is Aged 50 years and older

• Current or former smokers

• Anyone suffering from a chronic illness• diabetes, lung disease, cancer, kidney or liver disease

• Anyone with reduced immunity • organ transplant patients, those on special medications like

steroids

What Does Legionnaires’ Disease Look Like?

• After exposure to the bacteria, people may appear well, on average for 2 to 10 days

• At first, ill persons may feel generally unwell, lack appetite, or have a headache or muscle aches/pains

• Then, a high fever begins (up to 102—105°F)

• Next, more severe disease may appear• cough, abdominal pain, nausea/vomiting, diarrhea

Because the signs and symptoms of Legionnaires’ Disease look a lot like other diseases, it can be difficult to recognize and diagnose.

Timely diagnosis and treatment greatly improve patient outcomes!

https://www.physio-pedia.com/Legionnaire%27s_Disease

Potential sources of Legionella within water systems

• Cooling towers

• Hot tubs, spas, steam rooms, misters, decorative fountains

• Areas with high water age (new builds, shrinking cities)

• Homes with plumbing problems (home water heaters, dead ends)

“Most cases of legionellosis are the result of exposure to Legionella associated with building water systems.”

ANSI/ASHRAE 188

Legionella exposure

• Primary route of exposure is via inhalation of aerosols

• Much less common, Aspiration

• There has been one case of Person-to-person contact

https://www.cdc.gov/legionella/downloads/fs-legionnaires.pdf

Legionella: “opportunistic” pathogen

• Temperature, chemistry dependent

• Legionella is known to reside in biofilms attached to pipe walls and to replicate within predatory free-living protozoa (Falkinham et al., 2015)

• Suspended Legionella can be inactivated within 15 minutes by 0.4 mg/L chlorine (Yabuuchi et al., 1995)

• End result: much higher doses of chlorine are required to achieve disinfection

http://www.legionella-strategies.com/system-solutions.php

Typical hot water tanks are 120-140°F

Legionella growth is highly dependent on water temperature

http://www.who.int/mediacentre/news/releases/2017/bacteria-antibiotics-needed/en/ N. G. Love

Emerging pathogens: Antibiotic Resistant Bacteria

What can water system managers do?Maintain Hydraulic Integrity

Distribution system monitoring and modeling are critical to maintaining hydraulic integrity (NRC, 2006)

• Ensure positive water pressure to minimize intrusion

• “A minimum residual pressure of 20 psi under all operating conditions and at all locations (including at the system extremities) should be maintained.” (NRC, 2006)

• Where feasible, surge protection devices should be installed. (NRC, 2006)

• Minimize flow reversal

What can water system managers do?Maintain Chlorine Residual

As free chlorine increased in a census tract, probability of having a Legionnaires’ Disease case decreased

Proc Natl Acad Sci U S A. 2018 Feb 20;115(8):E1730-E1739.

What can water system managers do?Maintain Chlorine ResidualNumber of case reports of PAM by state of exposure, United States, 1962-2017.

https://www.cdc.gov/parasites/naegleria/state-map.html

Naegleria fowleri

Source: GETTY IMAGES

This case also highlights the role of adequate disinfection throughout drinking water distribution systems and the importance of maintaining vigilance when operating drinking water systems using source waters with elevated temperatures.

Cope et al. (2015)

What can water system managers do?Maintain Chlorine Residual

• If chlorine residual present and AOC <50 µg/L, then the water is biostable (LeChevallier et al. 1991)

• If chlorine is not present, AOC should be less than 10 µg/L to inhibit biofilm growth (van der Kooij, 1992)

• However, in a model hot water system (37ºC), operated using a water with low concentrations of AOC (< 10 µg/L), a biofilm formed that was sufficient to support the growth of the EOP Legionella (van der Kooijet al., 2005).

• Maintain minimum free chlorine residual of 0.2–0.5 mg/L

What can water system managers do?Reduce water age

“a primary reason for water quality problems within distribution systems is the advanced water age necessitated by the provision of adequate standby fire flow and redundant capacity.” (NRC, 2006)

• Remove unnecessary storage in system

• Minimize deadends

• Minimize stratification in storage facilities (Grayman et al. 2004)

• “a turbulent (high velocity) inlet jet, mechanical mixers, or hydraulic circulation systems” in storage tanks to prevent short circuiting

After: USEPA. 2002. Effects of Water Age on Distribution System Water Quality; The Water Industry Database, AWWA and AwwaRF, 1992.

Chemical Issues

Disinfection byproduct formationDisinfectant decay

Corrosion control effectivenessTaste and odor

Biological Issues

Disinfection byproduct degradationNitrification

Microbial regrowth/recoveryTaste and odor

Physical Issues

Temperature increasesSediment deposition

Color

Water Quality Problems Associated with Water Age

Design guidelines for water age: 72 hours maximum

Bold denotes water quality problem with direct potential public health impact

What can water system managers do?Listen to consumers• Tastes and odors detectable by the consumer are a common

indication of a loss of water quality integrity (McGuire, 1995).

• “most nuisance tastes and odors that cause customer complaints originate within customers’ premises” (NRC, 2006)

Example: Chlorophenols/bromophenols convert very odorous chloro/bromo-anisoles that have much lower thresholds of odor detection than the original compounds (Bruchet, 1999; Montiel et al., 1999)

3-Bromo-4-chloroanisole3-Bromo-4-Chlorophenol

Biological rxns

What can water system managers do?Connect with Public Health Officials

Risks, hazards, and disruptions, even minor events that typically go unnoticed, illuminate critical interdependencies

Water and Health Infrastructure Resilience and Learning (WHIRL)

Shawn McElmurry, Matt Seeger, Kristin O’Donnovan, Joanne Sobeck,Richard Smith, Paul Kilgore, Nancy G. Love, Branko Kerkez, JackieMacDonald Gibson

Award # 1832692

Resources:

• Pipeline cleaning methods

• Water main condition evaluation

• Reinstatement of Service Laterals

• when to replace a pipe rather than repair it

• how to notify all those affected and keep them informed during repairs

• how to record main-break information

• Ways to Balance Capacity and Water Age

• Microbial Growth… (Chapter 3)

• Corrosion Control (Chapter 7)

• Risk and Resiliency Evaluation (Chapter 2)

• Mutual Aid (Chapter 4)• Communications

(Chapter 5)

CDC Toolkit: Developing a Water Management Program to Reduce Legionella Growth and Spread in Buildings

https://www.cdc.gov/legionella/wmp/toolkit/index.html

CDC Emergency Water Websitewww.cdc.gov/healthywater/emergency

CDC Drinking Water Advisory Communication Toolkit

https://www.cdc.gov/healthywater/emergency/dwa-comm-toolbox/index.html

“Water, sanitation, and hygiene related emergency preparedness and outbreak response has become one of the most significant and crucial public health issues in recent history. Emergencies can include natural disasters (for example, hurricanes, floods, and droughts), man-made disasters (for example, chemical spills into waterways), and outbreaks (for example, infections linked to water exposure after a disaster).” CDC, 2018

https://www.cdc.gov/healthywater/emergency/index.html

References:ASHRAE (2018) ANSI/ASHRAE Standard 188-2018 - Legionellosis: Risk Management for Building Water Systems. Atlanta, GA 30329 www.ashrae.org

Bruchet, A. 1999. Solved and unsolved cases of taste and odor episodes in the files of Inspector Cluzeau. Water Science and Technology 40(6):15–21.

CDC (Centers for Disease Control and Prevention). 2016. Developing a Water Management Program to Reduce Legionella Growth & Spread in Buildings: A Practical Guide to Implementing Industry Standards. US Department of Health and Human Services: Atlanta, GA, USA.

Davis ML (2010) Water and Wastewater Engineering: Design Principles and Practice. Professional Edition (McGraw-Hill, New York).

Falkinham III, J. O., Hilborn, E. D., Arduino, M. J., Pruden, A., & Edwards, M. A. (2015). Epidemiology and ecology of opportunistic premise plumbing pathogens: Legionella pneumophila, Mycobacterium avium, and Pseudomonas aeruginosa. Environmental health perspectives, 123(8), 749-758.

Grayman, W. M., Rossman, L. A., Deininger, R. A., Smith, C. D., Arnold, C. N., & Smith, J. F. (2004). Mixing and aging of water in distribution system storage facilities. Journal‐American Water Works Association, 96(9), 70-80.

Jennifer R. Cope, et al.(2015) The First Association of a Primary Amebic Meningoencephalitis Death With Culturable Naegleria fowleri in Tap Water From a US Treated Public Drinking Water System, Clinical Infectious Diseases, Volume 60, Issue 8, 15 April 2015, Pages e36–e42, https://doi.org/10.1093/cid/civ017

LeChevallier, M. W., Schulz, W., & Lee, R. G. (1991). Bacterial nutrients in drinking water. Appl. Environ. Microbiol., 57(3), 857-862.

McGuire, M. J. 1995. Off-flavor as the consumer's measure of drinking water safety. Water Sci. Technol. 31(11):1–8.

Montiel, A., S. Rigal, and B. Welte. 1999. Study of the origin of musty taste in the drinking water supply. Water Science and Technology 40(6):171–177.

van der Kooij, D. (1992). Assimilable organic carbon as an indicator of bacterial regrowth. Journal American Water Works Association, 57-65.

van der Kooij, D., Veenendaal, H.R., and Scheffer, W.J.H. (2005). Biofilm formation and multiplication of Legionella in a model warm water system with pipes of copper, stainless steel and cross-linked polyethylene. Water Research 39, 2789-2798.

Walton, B. (2016). "Infographic: The Age of U.S. Drinking Water Pipes — From Civil War Era to Today " Retrieved 23 Jan. 2019, from https://www.circleofblue.org/2016/world/infographic-the-age-of-u-s-drinking-water-pipes-from-civil-war-era-to-today/.

Yabuchi E, Wang L, Yamayoshi T, Arakawa M, Yano I. (1995) Bactericidal effect of chlorine on strains of Legionella species. Kansenshogaku Zasshi. 1995 Feb;69(2):151-7.[Article in Japanese]