National Center for Emerging and Zoonotic Infectious Diseases

Water Supply and Treatment in Emergency Settings

Lee E.V. Gaeddert, PhD, EIT, REHS

Jonathan Yoder, Gouthami Rao, Amy Kahler

Waterborne Disease Prevention Branch

Centers for Disease Control and Prevention

70th Annual Environmental Engineering Conference

University of Kansas, April, 22nd, 2019

Takeaways - Water and Emergency Preparedness

▪ Water systems allow much of society to function

▪ Risk communication is critical

▪ Large populations (e.g. USVI and Puerto Rico) have unique factors that affect water-related risks

▪ Close coordination with local partners is critical to identify sustainable solutions to reducing water-related risks.

Outline

▪ Drinking water and emergencies

▪ Hurricanes Irma and Maria

▪ Water Systems in Puerto Rico and the US Virgin Islands

▪ US Virgin Islands Assessment

▪ Puerto Rico Cistern Emergency Protocol

Drinking Water Outbreaks and Emergencies

▪ Floods: NE, IA, MO, 2019

▪ Harmful algal blooms: Salem OR 2018

▪ Hurricanes: Texas, Florida, Puerto Rico, US Virgin Islands, 2017

▪ Water contamination, Flint MI, 2014 – 2016

▪ Bridger pipeline spill, Montana, 2015

▪ Legionella in water systems, NYC, 2015

▪ Naegleria in tap water, Louisiana, 2011 – 2015

▪ Harmful Algal Blooms, Toledo OH, 2014

▪ MCHM in Elk River, Charleston WV 2014

▪ Cryptosporidium, Baker City, OR, 2013

▪ Superstorm Sandy, multiple states, 2012

Water is connected to all critical infrastructure

▪ All water users will experience significantly degraded capabilities after 8 hours without water

– Even if they have emergency generators, they cannot operate without water

– Healthcare is particularly vulnerable; capability degraded 67% to 99% within two hours of loss of water services

National Infrastructure Advisory Council (NIAC) Report on Water Sector Resilience. July 2016

What is the health impact of distribution system interruption?

▪ Breaks, repairs, and maintenance

▪ ~240,000 water main breaks/year

▪ Opportunities for contaminant intrusion and biofilm disruption

▪ Public health challenge in detecting illnesses from distribution events

Resources - CDC Emergency Water Website

▪ Tools for Emergencies

– Household water treatment

– Outbreak questionnaires

– Surface cleaning

– Communication resources

– Guides and toolboxes

▪ Revised Emergency Supply Planning Guide for Healthcare Facility

www.cdc.gov/healthywater/emergency

How do we improve our communication to build trust?

▪ Crisis and Emergency Risk Communication (CERC) is a framework for dealing with public health emergencies

▪ The principles also apply to communication for water contamination– Be First– Be Right– Be Credible– Express Empathy– Promote Action– Show Respect

+

Hurricanes Irma & Maria – Sept 2017

▪ Hurricanes during 2017 caused widespread damage in Texas, Florida, Puerto Rico, and US Virgin Islands

– Historic flooding

– Wind damage to critical infrastructure

– Displacement of people

▪ Lack of power and floodwater led to increased exposure to unsafe water for drinking and other uses

▪ Lack of reliable, safe water impacted critical infrastructure, including healthcare and public health

Communicating about Emergency Water Treatment

Background – US Virgin Islands

▪ Population: ~105,000 (pre-hurricanes)

▪ Households: ~42,000 (pre-hurricanes)

▪ Three primary islands: St. Croix, St. Thomas, St. John (+ Water Island)

▪ Ethnic Groups

– Black or African American 76 %

– White 15.7%

– Asian 1.4%

– Other 4.9%

– Mixed 2.1%

▪ English, Spanish, Creole

▪ 13% pop are 65+ yrs

Background – US Virgin Islands

▪ >90% use rain catchment system; houses required to have cistern

– Majority are not linked to community system

▪ Limited USVI cistern contamination data; global data ranges from 24-90% contamination

– 1996 Cryptosporidium oocysts

▪ Drinking water source

– 90% of population also use bottled water

– 17% previously reported using cistern water

USVI Cisterns

▪ Filtration and/or

UV system

Background – Puerto Rico

▪ Population: ~3.4M (pre-hurricane)

▪ Households: ~1.26M (pre-hurricane)

▪ >90% use standard sized plastic tank, place on roof top, as a buffer for community water distribution system

▪ 1.2M households use PRASA (local utility)

▪ 65,000 households are ‘non-PRASA’

– Water provider varies (informal, community-led, private, etc.)

Puerto Rico

Puerto Rico

Cistern Design

Cistern-Based Water Systems

▪ Puerto Rico (distribution system)▪ USVI (rain catchment)

Engineering Design Concept

Water SupplyConcerns:• Quality; FCR, pH, temp,

turbidity, metals, pathogens

• Intermittent supply • Temperature differentials

(supply vs cistern water) Cistern Characteristics Concerns:• Material; biofilm growth• Material; heat generation • Leaks/closed-open• Structure; stagnant zones, water mixing/contact time,

sediment buildup, inlet/outlet location

Human-Cistern InteractionsConcerns:• Use frequency – retention time• Cistern disinfection• Water disinfection• Water access

Animal-Cistern InteractionsConcerns:• Access to openings/leaks• Fecal/urine contamination

Cistern

Water QualityConcerns:• Fecal contamination • Pathogens • pH-temp-turbidity (chlorination

factors)

Engineering Design Concept – Closed

Water SupplyConcerns:• Quality; FCR, pH, temp,

turbidity, metals, pathogens

• Intermittent supply • Temperature differentials

(supply vs cistern water) Cistern Characteristics Concerns:• Material; biofilm growth• Material; heat generation • Leaks/closed-open• Structure; stagnant zones, water mixing/contact time,

sediment buildup, inlet/outlet location

Human-Cistern InteractionsConcerns:• Use frequency – retention time• Cistern disinfection• Water disinfection• Water access

Animal-Cistern InteractionsConcerns:• Access to openings/leaks• Fecal/urine contamination

Cistern

Water QualityConcerns:• Fecal contamination • Pathogens • pH-temp-turbidity (chlorination

factors)

Engineering Design Concept – Open

Water SupplyConcerns:• Quality; FCR, pH, temp,

turbidity, metals, pathogens

• Intermittent supply • Temperature differentials

(supply vs cistern water) Cistern Characteristics Concerns:• Material; biofilm growth• Material; heat generation • Leaks/closed-open• Structure; stagnant zones, water mixing/contact time,

sediment buildup, inlet/outlet location

Human-Cistern InteractionsConcerns:• Use frequency – retention time• Cistern disinfection• Water disinfection• Water access

Animal-Cistern InteractionsConcerns:• Access to openings/leaks• Fecal/urine contamination

Cistern

Water QualityConcerns:• Fecal contamination • Pathogens • pH-temp-turbidity (chlorination

factors)

Closed Systems (within distribution system) –Non-Emergency Situations

▪ ~11-12 studies (primarily LMICs), 2 dissertations, 2 reviews, 6+ guidelines

– Majority of systems (in studies) were contaminated

– Temperature, retention times, turbidity-chlorine residual

– Mixed results on cistern material

– Inlet-outlet placement important for stagnant zones

– Cistern cleaning/disinfection, 1-3 times/yr help reduce microbial growth

Open Systems (rain harvested) –Non-Emergency Situations

▪ ~19 E. coli studies; ~22 pathogenic studies*

– 24% to 92% E. coli positive samples (n=19 studies)

– 54% (660/1222) mean E. coli positive samples (n=17 studies)

– Key factors

• Aerosol deposition (wind speed/direction), tree litter, animals, roof material, indigenous biofilm/sediment in cistern

*Hamilton et al. 2019 review

2019 USVI Cistern Study

▪ Primary question: What is the prevalence of E. coli in cisterns across USVI?

▪ Secondary questions:

– What risk factors are associated with increased levels of E. coli in cisterns?

– Is there a difference between E. coli levels between cistern and tap for different types of “treatment”?

2019 USVI Cistern Study Results

▪ Full study (~400 households)

– 80% of cistern water taken directly from the cistern hatch tested positive for E. coli

– 58% of tap water taken from kitchen taps tested positive for E. coli

▪ Current USVI activities:

– Identify primary environmental contributors to cistern water contamination

– Identify low-cost water treatment options for households

Puerto Rico

▪ Previous and current activities:

– Hospital emergency preparedness for water

– Improving communications on water to general public

• Translating material

– Household emergency water preparedness guide

• How do you prepare?

• What do you do after?

– Literature review on best practices for maintaining a rooftop cistern

Takeaways - Water and Emergency Preparedness

▪ Water systems allow much of society to function

▪ Risk communication is critical

▪ Large populations (e.g. USVI and Puerto Rico) have unique factors that affect water-related risks

▪ Close coordination with local partners is critical to identify sustainable solutions to reducing water-related risks.

For more information, contact CDC1-800-CDC-INFO (232-4636)TTY: 1-888-232-6348 www.cdc.gov

The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention.

Thank you!

www.cdc.gov/healthywaterwww.cdc.gov/healthywater/emergency

Acknowledgments:Jonathan Yoder, CDCAmy Kahler, CDCGouthami Rao, CDCJennifer Murphy, CDCMatt Lozier, CDCDavid Berendes, CDC

Lee E.V. GaeddertEmail: oxg1@cdc.gov