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Healthcare Water System Repair and Recovery Following a Boil Water Alert or Disruption of Water Supply

A close up picture of clear, clean water splashing

Excerpted from the Guidelines for Environmental Infection Control in Healthcare Facilities (2003)pdf icon [PDF – 2.31 MB]. Recommendations of CDC and the Healthcare Infection Control Practices Advisory Committee (HICPAC),  Emergency Water Supply Planning Guide for Hospitals and Healthcare Facilities (2012)pdf icon [PDF – 2.07 MB] and standards published by the Association for the Advancement of Medical Instrumentation (AAMI)external icon), United States Pharmaocopeia (USP), and manufacturers’ instructions.

The Joint Commission and the Centers for Medicare Services (CMS 2016external icon) [PDF – 1.27 MB] require all hospitals to have plans which address facility response for recovery from both internal and external disasters. The plans are required to address:

  1. general emergency preparedness.
  2. staffing.
  3. regional planning among area hospitals.
  4. emergency supply of potable water.
  5. infection control and medical services needs.
  6. climate control.
  7. remediation.

Healthcare facilities should develop an Emergency Water Supply Plan (EWSPpdf icon [PDF – 2.07 MB]) to prepare for, respond to, and recover from a total or partial interruption of the facilities’ normal water supply. Water supply interruption can be caused by several types of events such as a natural disaster, a failure of the community water system, construction damage or even an act of terrorism. Because water supplies can and do fail, it is imperative to understand and address how patient safety, quality of care, and the operations of your facility will be impacted.

Infection Control Recommendations To Be Used During a Boil Water Alert
Bottled, Sterile Water Should Be Used for the Following:
Drinking Water
  • Alert patients, families, staff, and visitors not to consume water from drinking fountains, ice, or drinks made from municipal tap water, while the advisory is in effect, unless the water has been disinfected (e.g., by bringing to a rolling boil for >1 minute) or use commercially available bottled water (Sehulster et al. 2004pdf icon [PDF – 2.31 MB]).
  • Do not use ice for drinks, or other procedures (Sehulster et al. 2004pdf icon [PDF – 2.31 MB]).
Wound Care
  • Do not use tap water. Consider using either boiled, disinfected, or bottled sterile water.
  • Restrict burn patients and patients with open sores or wounds from whirlpool treatments and hydrotherapy for debridement unless water for use is filtered or treated (boiled, disinfected).
  • For advisories without evidence of contamination, tap water may be used for patients with healthy immune systems.
  • Use bottled or boiled water for infants, young children and anyone with a weakened immune system, wounds, or abrasions.
  • For advisories with evidence of contamination (microbial/chemical) do not use tap water for bath or shower.
Humidifiers (free standing, ventilators, or other equipment)
  • Use sterile water as normal for ventilators (CDC 2003).
  • Use bottled, sterile water for isolettes (see also instructions for use).
  • Use sterile, or distilled bottled water for CPAP machines.
  • Check manufacturer’s instructions for use for type of water to be used typically they may indicate the use of sterile, distilled, or demineralized bottled water for humidifiers.
Sterile processing (CDC and AAMI)
  • Water for device reprocessing and sterilization should meet the AAMI recommended standards; see Table 1.
Table 1. Categories and recommended levels of water quality for medical device reprocessing
 Type of Water  Utility Water   Utility Water  Critical Water
 Water Use  Flushing  Washing or rinsing  Final Rinse, Steam
 Hardness  <150 mg/L  <150 mg/L  <1 mg/L
Conductivity  <500 µS/cm  <500 µS/cm  <10 µS/cm
pH  6-9  6-9  5 – 7
Total Organic Carbon (TOC)  NA  NA  <1 mg/L
Chlorides  <250 mg/L   <250 mg/L  <1 mg/L
Bacteria1  NA  <10 CFU/mL  <10 CFU/mL
Endotoxin2  NA  <20 EU/mL  <10 EU/mL

NA = not applicable.

1 Water should be drinking water quality; rinse and final rinse (for devices that are high-level disinfected) and water for sterilization should contain total cell counts <10 CFU/mL.

2 Units of measure for endotoxin in endotoxin units or EU/mL. There is no limit for endotoxin in utility/drinking water; however devices and reprocessed instruments should be nonpyrogenic, which is why rinse and final rinse, and steam have limits.

  • If water treatment is in place sterile processing may continue to operate; special attention to pretreatment may be warranted (e.g., reverse osmosis alone, reverse osmosis with deionization polishing, and filtration to remove microbes and endotoxin).
  • If no additional water treatment is in place, suspend operations until water system has been remediated and safe drinking water has been restored or consider installing point of use water treatment to meet the production of water that meets requirements for operation of the specific piece of equipment; Rutala, Weber, HICPAC, 2008; Sehulster et al. 2004pdf icon [PDF – 2.31 MB]).
  • Perform enhanced clinical surveillance for healthcare-associated infections caused by waterborne pathogens (see partial list in additional resources below including Legionella-specific considerations).
  • Use both syndromic surveillance and microbiology laboratory data.
  • If healthcare-associated cases (i.e., respiratory, blood stream, surgical site, gastrointestinal, skin and soft tissue infections) of waterborne disease occur, conduct an epidemiologic investigation to identify source and potential transmission routes.
Remediation Strategies for Healthcare Water Distribution Systems

The water management team should meet to review the situation, define goals and implement a plan to return the water system to normal operation per steps outlined in their water management program.

Extended Boil Water Alerts and Steps to Take after Alerts Are Lifted
  • If the boil water alert is for an extended period of time and microbiological contamination is suspected, consider a more aggressive remediation. Consider consulting the State Health Department and Drinking Water Administrator about implementing short term supplemental treatment.
  • Once the boil water alert has been lifted flush all fixtures (e.g., faucets, drinking fountains) and equipment and restart. Flush faucets and fixtures until detectable chlorine can be detected.
    • Flush for > 5 minutes and until residual disinfectant is detected.
    • Discard ice from ice machines and clean and sanitize per manufacturers’ instructions.
    • If chlorine cannot be detected at point of use after flushing one may need to consider supplemental disinfection (Drinking water regulations will apply, by performing supplement disinfection the institution would now be considered a small public water system).
  • Remove point of use filters and flush outlets for several minutes before installing new filters (e.g., ice-machines, sinks and showers if present).
  • Run water softeners through a regeneration cycle.
  • Drain, disinfect, flush, and refill water storage tanks if needed.
  • Change pre-treatment filters, backwash carbon tanks, regenerate softener, and clean and disinfect RO membranes, disinfect dialysis distribution loops.
  • Corrective decontamination of the hot water system might be necessary after a prolonged disruption in service or a cross-connection with sewer lines has occurred.
    • Decontaminate the system when the fewest occupants are present in the building to reduce possible exposure to waterborne pathogens (e.g., nights or weekends) (ASHRAE: 12:2000pdf iconexternal icon [PDF – 799 KB]; Sehulster et al. 2004pdf icon [PDF – 2.31 MB]).
    • If using chlorination, add enough chlorine, preferably overnight, to achieve a free chlorine residual of >2 mg/L (ppm) throughout the system (ASHRAE: 12:2000pdf iconexternal icon [PDF – 799 KB]).
      • Flush each outlet until chlorine odor is detected.
      • Maintain the elevated chlorine concentration in the system for >2 hours (but <24 hours).
    • Use a very thorough flushing of the water system instead of chlorination if a highly chlorine-resistant microorganism (e.g., Cryptosporidium spp.) is suspected as the water contaminant.
  • Check steam system if clean steam is used for autoclaves in sterile supply.
    • Check water quality used for steam generation.
    • Check with manufacturer for instructions for bring system back online following a contamination event.

Hemodialysis facilities require large amounts of water to treat their patients. It is also essential for the program to maintain clear communications with their water provider. This above link provides information for dialysis programs following disasters and includes information on:

  • Continuation of treatment during boil water advisories.
  • Safe use of tanker delivered water.
  • Technical considerations when bringing dialysis systems back online following a disaster.

Dental clinics also use water in the treatment of patients. Guidance for dental practices impacted by boil water advisories can be found at the above link from the Division of Oral Health above. In short:

  • Do not deliver potentially contaminated water to the patient through the dental unit water lines (DUWL).
  • It is okay to use the dental units for patient treatment if they are isolated from the municipal system by an FDA cleared water treatment device or reservoir.
  • Have patients rinse with bottled or distilled water until the boil water advisory is cancelled.
Environmental Monitoring
  • Consider periodic testing of disinfectant residual at point of use sites as determined by your water management program.
  • Consider using heterotrophic plate count (< 500 CFU/mL) to measure water quality.
  • For special types of water (some examples include water used in compounding pharmacy, for dialysis and clinical laboratory reagent water) follow appropriate guidelines [e.g., CLSI, AAMI, CMS participation of coverage (see references)].
  • After system remediation review and reemploy the facilities water management plan (CMS 2017pdf iconexternal icon [PDF – 121 KB]; Water System Maintenance).

AHSRAE. Minimizing the risk of Legionellosis associated with building water systemspdf iconexternal icon [PDF – 799 KB]. ASHRAE Guideline 12-2000, ASHRAE, Atlanta, GA, 2000.

CDC. Dialysis care after a disaster. (Avaliable from

CDC. Guidelines for preventing healthcare—associated pneumonia, 2003. MMWR 2004;53(RR06):1-36. (

CDC, AWWA. Emergency Water Supply Planning Guide for Hospitals and Healthcare Facilitiespdf icon [PDF – 2.07 MB]. CDC Atlanta, GA: 2012

Clinical Laboratory Standards Institute. Preparation and testing of reagent water in the clinical laboratory; approved guideline, fourth editionexternal icon. CLSI Document C3-A4. Clinical and Laboratory Standards Institute, Wayne, PA 2006.

CMS. Medicare and Medicaid Programs; Emergency Preparedness Requirements for Medicare and Medicaid Participating Providers and Suppliers. Final rule. Fed Regist. 2016;81(180):63859-4044. ( iconexternal icon [PDF – 1.27 MB])

CMS. Requirement to Reduce Legionella Risk in Healthcare Facility Water Systems to Prevent Cases and Outbreaks of Legionnaires’ Disease (LD). CMS, Baltimore, MD, June 2, 2017pdf iconexternal icon [PDF – 121 KB].

CMS. Conditions for Coverage for End-Stage Renal Disease Facilities. Federal Reg 2008;73(73): 20370-20484pdf iconexternal icon [PDF – 121 KB].

FDA. FDA Offers Tips about Medical Devices and Hurricane Disastersexternal icon. FDA, CDRH, Silver Spring, MD.

EPA. Safe Drinking Water Regulations. ( icon)

FDA. Heater-Cooler Devices: Information for Health Care Providers and Staff at Health Care Facilities.external icon FDA, CDRH, Silver Spring, MD.

Rutala WA, Weber DJ, HICPAC.   Guideline for Disinfection and Sterilization in Healthcare Facilities (2008) (

Sehulster LM, Chinn RYW, Arduino MJ, Carpenter J, Donlan R, Ashford D, Besser R, Fields B, McNeil MM, Whitney C, Wong S, Juranek D, Cleveland J. Guidelines for environmental infection control in health-care facilities. Recommendations from CDC and the Healthcare Infection Control Practices Advisory Committee (HICPAC). Chicago IL; American Society for Healthcare Engineering/American Hospital Association; 2004. [Last Update February 15, 2017; available from icon [PDF – 2.31 MB]]

General References

Hsu J, Del Rosario MC, Thomasson E, Bixler D, Haddy L, Duncan MA. Hospital impact after a chemical spill that compromised the potable water supply: West Virginia, January 2014. Disaster Med Public Health Prep. 2017;6:1-4.

Laine J, Huovinen E, Virtanen MJ, Snellman M, Lumio J, Ruutu P, Kujansuu E, Vuento R, Pitkänen T, Miettinen I, Herrala J, Lepistö O, Antonen J, Helenius J, Hänninen ML, Maunula L, Mustonen J, Kuusi M; Pirkanmaa Waterborne Outbreak Study Group. An extensive gastroenteritis outbreak after drinking-water contamination by sewage effluent, Finland. Epidemiol Infect 2011;139(7):1105-13.

Mitchell L, Anderle D, Nastally K, Sarver T, Hafner-Burton T, Owens S. Lessons learned from Hurricane Ike. AORN J 2009;89(6):1073-8.

Nates JL. Combined external and internal hospital disaster: impact and response in a Houston trauma center intensive care unit. Crit Care Med. 2004;32(3):686-90.

Norcross ED, Elliott BM, Adams DB, Crawford FA. Impact of a major hurricane on surgical services in a university hospital. Am Surg. 1993;59(1):28-33

Shelton S, Hamm J, Olatosi B, Johnson RO. Recovery of Surgical Equipment Sterile Processing During a Floodwater Boil Advisory. Disaster Med Public Health Prep 2017 Aug 14:1-4. doi: 10.1017/dmp.2017.70. [ahead of print]

Additional Resources

Food, Water, Sanitation, and Hygiene Information for Use Before and After a Disaster or Emergency:

Clusters of infections due to these organisms should alert one to suspect water as a potential source. These opportunistic pathogens are normal inhabitants of water and not considered contaminants. This list does not include those that represent contamination with sewage (typically enteric pathogens and enteric viruses)

Selected Examples (partial listing):

Gram negative bacteria

Pseudomonas and other organisms formerly belonging to the genus Pseudomonas

  • Pseudomonas aeruginosa
  • Pseudomonas putida-P. fluorescens
  • Burkholderia cepcia complex (B. cepacia, B. cenocepacia, at least 8 other genomospecies)
  • Cupriviadus (Ralstonia) pauculus
  • Herbaspirillium
  • Methylobacterium spp.
  • Ralstonia pickettii, Ralstonia mannitolilytica
  • Sphingomonas paucimobilis, Sphingomonas mucosissima, other Sphingomonas spp
  • Stenotrophomonas maltophilia

Acinetobacter baumannii, A. calcoaceticus

Alcaligenes xylosoxidans, A. faecalis,

Aeromonas hydrophila, Aeromonas spp

Elizabethkingia anaophelis, E. meningosepticum

Legionella pneumophila, Legionella spp

Non-fecal coliforms

  • Enterobacter cloacae
  • Klebseilla spp
  • Pantoae aggloerans
  • Rahnella aquatilis
  • Serratia liquifaciens, Serratia marcescens

Nontuberculous mycobacteria (NTM or Environmental Mycobacteria)

M. abscessus clade (M. abscessus, M. bolettii, M. massiliense)
M. chelonae
M. mucogenicum clade (M. mucogenicum, M. phociacum)
M. fortuitum clade (M. fortuitum, M. cosmeticum, mageritiense, M. porcinum, M. septicum)

M. smegmatis clade (M. goodii, M. wolinskyi)

M. aurum
M. simiae
M. avium complex (M. avium, M. intracellulare, M. chimaera, M avium ss hominissuis, M. columbiense)
M. scrofulaecuem

M. parascrofulaceum

M. xenopi
nonchromogenicum clade (M. nonchromogenicum, M. triviale, M. terrae)
gordonae (only among patients with severe immune deficiency)

Other bacteria/actinomyces

Microbacterium spp

Tsukamurella spp

Rhodococcus equi, Rhodococcus spp

Gordonae spp


Yeasts (eg. Candida parapsilosis, C. tropicalis)

Aspergillus fumigatus, A. niger

Fusarium spp

Exophiala spp.

Protozoa: Acanthameba spp, Vermamoeba vermiformis, Naegleria spp icon [PDF – 13.3 MB]

  • See the “Factors external to buildings that can lead to Legionella growth” section on page 4 in toolkit for a brief background on the role construction, water main breaks, and changes in municipal water quality can play in Legionella growth within buildings.
  • See the “Identifying and Investigating Legionnaires’ Disease Cases” section on page 24 in toolkit for a recommendation to test patients with healthcare-associated pneumonia if changes in water quality may lead to Legionella growth (e.g., low residual disinfectant levels, temperatures permissive to Legionella growth, nearby construction, areas of stagnation).

  • See the “Indications for Legionnaires’ Disease Testing” section for a note about testing healthcare-associated pneumonia cases when changes in water quality may lead to Legionella growth are identified in a healthcare facility.
  • See the “Preferred Diagnostic Tests” section for guidance about appropriate diagnostic testing.

CDC Legionella team (epidemiology, lab, and environmental health staff) can be reached at for questions, concerns, and technical assistance.

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