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Managing Risks of Legionella in Building Water Distribution Systems

UF TREEO 2018 Presentation Agenda

• Legionella Management• Legionella Basics

• Regulations/Guidelines Legionella Control

• Legionella Field Survey – VA Medical Site

• Suggested Best Management Practices

30+ Years in Business

250+ Municipal and Industrial/Commercial Clients

• Cross Connection Programs/Surveys

• Legionella Water Management

• Water Distribution Quality Studies

• Sampling Programs

• Pipe Labeling Studies

• System Drafting (Chilled Water, Waste Water, etc.)

One Goal We visit some neat places…

And not so neat…

Legionella Basics

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Recent Legionnaires Disease Cases

• City of Flint (2014-2015)

• VA Hospitals/Properties

• Playboy Mansion?!?!

• Hotels

• Hospitals

The Happiest Place on Earth?!?!

No, Florida is not Exempt… Oh No, Do not mess with our BEER!!!!

“Whether or not the Warsteiner brewery is

found to be the breeding ground for

the Legionella bacteria, officials have been making it clear

that the beer is completely safe to

drink.”

Legionella Basics• Bacteria which thrives in aquatic environments -

groundwater, biofilms, surface waters, soils, etc.

• Found in man made/engineered systems:

• Domestic water supplies, cooling towers, domestic hot water supplies, showers, spas, misters, decorative fountains, etc.

• Categorized in 1976 (at least 50 species today):

• Legionnaires convention

• Cooling Tower-cause of illness/death

“Legionellosis”

• Many cases of pneumonia type illnesses throughout USA – caused by Legionella bacteria (LB)• Estimated 8000 to 18,000 cases per year-likely many more1

• Legionnaire’s Disease/Pontiac Fever – caused by inhaling/aspirating Legionella bacteria

• US standard/guidelines for control, management of LB:

• Few states have guidelines (MD, TX, and PA)

• PA has highest rate of reporting disease likely due to increased vigilance/monitoring

1. Marston BJ, Plouffe JF, File TM Jr, Hackman BA, Salstrom SJ, Lipman HB, et al. Incidence of community-acquired pneumonia requiring hospitalization. Results of a population-based active surveillance Study in Ohio. The Community-Based Pneumonia Incidence Study Group. Arch Intern Med. 1997;157(15):1709–18.

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Legionellosis-Data (CDC)

• 87% of Legionellosis cases reported ages >40

• Men twice as likely to become ill vs. women

• Children < 15 years of age rarely become ill

• Most cases reported are “sporadic” – not associated with outbreak

• Age, gender, smoking, alcoholism, immunosuppression, autoimmune diseases – risk factors

Legionellosis

• Preventable, and treatable with antibiotics

• NOT “communicable”

• 90% of cases have incubation period of 3 to 14 days

• At Risk Water Systems: Hot water systems, cooling towers, high pressure wash systems, Spas, decorative fountains, irrigation systems

Legionella Bacteria Growth Requirements

1. Water pH 5 to 9

2. Growth range = 68 to 122°F (98 optimal) – Significance?

3. Moist environments

4. Oxygen

5. Iron, sediment, scale, biofilm

City Water Suppliers

• PWS must meet EPA National Primary Drinking Water Standards, BUT……

• No enforceable MCL for Legionella! Only Maximum Contaminant Level Goal (MCLG)…

• Is Legionella controlled 100% of the time in city water distribution systems? What level is safe or dangerous?

• City can mitigate legionella by:

• Chlorinating effectively

• Flushing programs/eliminate terminal end mains

• Cross Connection Control Program

• Water quality monitoring/treatment

Private Water Systems

• Private Water Users must adhere to OSHA 1910.141, Plumbing Code, Health Department for drinking water quality

OSHA General Duty Clause

• Hotels, Offices, Hospitals, Factories, Grocery Stores, etc. have had reported Legionella related illnesses

• New standard for Legionella mitigation/risk management…….

General Water Management Plan Development

1. Develop Water Process Flow Diagrams (Potable and Non-Potable Water Systems)

2. Perform Hazard Identification, Analysis and Risk Characterization

3. Identify/establish “Critical Control Points”

4. Establish control measures/limits for critical control points

5. Plan Validation (i.e., Sampling) and Verification (Program Management)

ASHRAE 188 Standard

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Legionella Field Survey – Medical Site

Project Scope

1) Developed detailed domestic hot and cold plumbing drawings -12 buildings• ID all plumbing equipment, evaluate

cross connection measures, dead legs, operating inefficiencies

2) Assist in developing LegionellaWater Management Plan for each building

3) Recommendations/Corrective Actions/Report

Basic Concept-Water Safety Plan Development

Evaluate Water Systems and ID Hazards – Biological,

Physical, Aerosol, Chemical, Radiological

Can this water system allow for Legionella bacteria to

amplify, become aerosolized and exposed to people?

Develop Water Management Plan - Establish Hazard Control Measures for “Critical Control

Points” High Risk Systems

“Validate” controls are working (Legionella

sampling, etc.)

Process Flow Diagram Sample

Pod A (POEA)

Pod B (POEB)

Pod D (POED)

Community Water Supply (CWS1)

Pod E (POEE)

Pod C (POEC)

“Heat Exchanger #2”

Central Hot Water Supply

(Pod E Mech. Room) (DHW2)

“Heat Exchanger #1”

Central Hot Water Supply

(Pod E Mech. Room) (DHW1)

Thermostatic Mixing

Valve

Personal Rooms, Bath

Rooms,

Laundry Room (POUA)

Personal Rooms, Bath

Rooms, Laundry Room

(POUB)

Personal Rooms, Bath

Rooms, Laundry Room

(POUC)

Personal Rooms, Bath

Rooms, Laundry Room

(POUD)

Personal Rooms, Bath

Rooms, Public Restroom

(POUE)

Kitchen and Cafeteria

(POUE)

Domestic Hot Water Return →

1. RECEIVING

2. COLD WATER

POINT OF ENTRYCRITICAL CONTROL POINT

6. DOMESTIC HOT

WATER MAKEUPCRITICAL CONTROL POINT

7. DOMESTIC HOT WATER

DISTRIBUTION SYSTEMCRITICAL CONTROL POINT

8. WASTE

← Domestic Hot Water Supply

Sanitary Sewer

Domestic hot water system supplies kitchen operations, bathing showers, sinks and

commercial clothes washing with no zone mixing/anti-scald valves.

Potable cold water system generally supplies bathing showers and sinks, toilets, urinals, ice machines, drinking fountains, laundry equipment, hose bibbs, utility sinks in

Pods A through D. Pod E also has makeup to heating system, eyewash, kitchen equipment, hose bibbs, and utility

sinks.

Decorative Fountain

(DEF1)

Hot Water

Heating Makeup

3. DECORATIVE

FOUNTAINCRITICAL CONTROL POINT

PROCESS STEPS

5. COLD WATER

POINT OF USECRITICAL CONTROL POINT

Domestic Hot Water

Distribution System (DHWS1)

Softened Hot Water

Supply from Building 500 (DHW3)

Domestic Soft Hot Water Supply and Return from

Building 500 to Pod E Kitchen only - not in use

Refer to “Building 100 Process Flow Diagram”

Domestic Soft Hot ←

Water Supply

Domestic Soft Hot

Water Return →

4. HOT WATER HEATING

• Building domestic cold water supply• Cross connections, dead legs, low turnover areas

• Domestic Hot Water Tanks/Plumbing Systems

• Cooling water systems

• Ice machines, eyewashes, baths/pools

• Building humidification, decorative fountains

Building Field Survey-Potential Areas of Risk for Legionella Plumbing System Risks – Legionella Growth!!!

• Dead legs/low use water lines (hot and cold)

• Low chlorine

• Heaters below 140°F and hot water piping systems below 124°F

• Recirculating/return pumps not working effectively

• Oversized tanks/vessels or piping in relation to water demand (residence time > 24 hours)

• Cross connections with sanitary sewer, irrigation, etc.

• No insulation on piping

• Cold water piping becoming heated

• Significant water hammer/ pressure fluctuations

• Old piping/tanks

• Rubber materials, plastics vs. copper pipe

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Domestic Water Heaters – StudyAlary, et. al

40% of homes with an electric water heater reported the detection of legionella in tank

0% of homes with gas heaters reported legionella in tank

Homes in older areas of community more susceptible to detection of legionella

Type, age and size – main factors

At 151° F, Legionella dies within 2 minutes

At 140 °F, Legionella dies within 32 minutes

At 122° F, Legionella can survive but do not multiply

82.2° C

76.7° C

71.1° C

65.5° C

60.0° C

54.4° C

48.9° C

43.3° C

37.8° C

32.2° C

26.7° C

21.1° C

15.6° C

10.0° C

Water Temperature and Legionella

• Water heaters need capability of

heating water to 158° F for disinfection

• Commercial water heaters have a 180° F T-stat limit

• Residential water heaters have a 160° F T-stat limit

• Instantaneous heaters typically are not capable of heating water to disinfection temperature ranges

Water Temperature effects on Legionella Bacteria

ASHRAE Guideline

1. HW Min Storage Temp = 130° F for circulated tanks

2. HW Min Storage Temp = 140° F for uncirculated tanks

3. HWR Min Temp before return to HW tank = 124° F

Ideal Growth Range 95° F -115° F

Tempered Water 85° F -110° F

Legionella Growth Range 68° F -122°F

Below 68° F, Legionella can survive, but are dormant. Cold water in storage tanks, piping, decorative fountains and other equipment, ideally, should be kept below 68° F

Disinfection Range 158° F- 176° F

180° F

170° F

160° F

150° F

140° F

130° F

120° F

110° F

100° F

90° F

80° F

70° F

60° F

50° F

Scalding Considerations

Temperature Amount of Time to Cause Serious Burn

120°F More than 5 Minutes

125°F 1.5 to 2 Minutes

130°F 30 Seconds

135°F 10 Seconds

140°F 5 Seconds

145°F <5 Seconds

150°F 1.5 Seconds

155°F 1 Second

Maintain tank temperature at >140°F

Maintain hot water piping at >124°F

Routine tank/system pasteurization

Routine system draining

Inspect/test master mixing valves

Domestic Hot Water Tank and Hot Water System Control Measures

Return pump on at all times

At least daily turnover of tank

Ensure freshest water possible supplies tank (high Cl2)

Inspect expansion tanks regularly

Install antiscald valves where required

Maintain/disinfect shower heads and hoses

Insulate hot water piping

Flush stagnant/low flow areas

Copper piping-hot water

Domestic Hot Water Tank and Hot Water System Control Measures

Mixing valves-install as close to end use as possible (i.e., sink, etc.)

Use point of use/instantaneous water heaters where possible

Cross connections (i.e., janitor sink soap dispensers)

Domestic Hot Water Systems

Domestic Hot Water Source

DHW Return Pump

Sinks, Showers, etc.

Sinks, Showers, etc.

124°F→ Hot Water Supply

←124°F Hot Water Return

Antiscald Protection Required 110°F required at outlets ASSE

1017, ASSE 1062, etc.

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Cross-ConnectionImproper BackflowPreventerHot Water Source

Inspection Items

Pipe supply material Pipe labeling Piping leaks Expansion Tanks Hot Water Vessel Temperature

Settings Hot Water Outlet Temperature Hot Water Return Temperature Check Valve Installations

Cross-ConnectionImproper BackflowPreventerHot Water Source

Inspection Items

Master Mixing Valves Hot Water Return Pumps Hot Water Vessel Recirculation Pumps Number of outlets served Types of outlets served

Showers, sinks, kitchen operations Water Supply

Soft Water, City Water Quality

Might be time for a new tank?System Leaks

• May be indicative that equipment needs maintenance or replacement

• Impacts heating capacity

Case Study- Insufficient Heat in System

Target Domestic Hot Water Piping System Temperature = 124°F

• Semi-instantaneous heat exchanger set 130-136°F (Typ. 2)

• 5 Wing - Community Living Center• Highest temperature in piping

system is 112°F, recorded 15 feet from heat source

• Why?

Case Study-Insufficient Heat in System

Target Domestic Hot Water Piping System Temperature = 124°F

• Semi-instantaneous heat discharge 130-136°F

• Recirculating and return pumps working

• Highest use is immediately downstream = Kitchen Operations = high hot water use

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Case Study-Insufficient Heat in System

Master Thermostatic Mixing Valve Downstream Heating

• Tempered water temperature gauge = 124°F

Domestic Cold Water

Domestic Tempered Hot Water

Domestic Hot Water

124°F

Case Study-Insufficient Heat in System

15 Feet Downstream of Mixing Valve Gauge = 108°F

• Mixing valve and temperature gauge malfunctioned!

• Staff assumed hot water was at 124°F

Case Study-Insufficient Heat in System

Domestic Hot Water Return Piping System Temperature = 104°F

• Temperature difference of 4 to 8°F piping system from supply to return

• May possibly need supplemental return pump – 2 separate return line systems, 1 pump

• Consider dedicated heater for kitchen operations

Maintain temperatures <67°F

Rotate booster pumps weekly

Eliminate any dead legs in cold water piping system

Flush known low use areas

Test backflow prevention assemblies

Manage expansion tanks, hammer arrestors

Domestic Cold Water System Control Measures

Flush strainers

Insulate cold water piping, run cold water pipe below hot

Maximize chlorine levels through flushing, strategic plumbing

Eliminate cross connections

New Construction – utilize backflow preventer to isolate area, chlorinate new mains (AWWA C651-14)

Cross-ConnectionImproper BackflowPreventerInspection Items

Ice Machines

Water supply - backflow prevention Filters (type, change frequency) Hands free, manual scoop Water cooled vs. air cooled condenser Population Served (high risk

population vs. general public) Ice Machines may require routine

cleaning/disinfection/inspection

Inspection Items Eye Washes

Water supply – cold vs. tempered Shared supplies Pipe supply material Shower vs. eyewash only Weekly Flushing Schedule

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Inspection ItemsDead Legs

• Pressurized sections of water piping – no use/flow

• Bacteria proliferation (i.e., Legionella) and corrosion issues

• May introduce water of poor water quality into active mains

• Dead legs should be eliminated/removed, or disconnected and capped in place

Dead Legs

Pipes Pressurized w/ Water and Capped

Dead Legs?

Pipes Pressurized w/ Water and Capped

Dead Legs

Pipe Pressurized w/ Water and Capped

Operational Dead Leg-Backup Soft Water

Domestic Soft Hot Water Backup

Domestic Hot Water Supply

X

Backflow Prevention Assemblies

• Test annually or as required• Flush strainers at least annually • Failed assemblies may allow for

contaminated water to enter distribution system (i.e., bacteria such as Legionella), thus posing hazard

• Fire Systems – take precautions during fire flow tests/assembly testing

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Chemically treated pressurized

cooling water may contain Legionella

–backflow into potable water supply

Potable water supply with

no backflow protection

Cross-Connection Subject to Backpressure Processes and Kitchen Share Supply- Hospital Domestic Water System Exposed to Process Soft Water.

What’s wrong here?

Case Study – Process Cold Soft Water

Double Check Valve Assembly (Backflow

Preventer)

Kitchen Operations

Domestic Hot Water Heat Exchanger

Water Softeners (2)

Automated Endoscope

Reprocessors

Reverse Osmosis Systems/Process Heat Exchangers Humidification

Hospital Domestic Hot Water Supply –

Backup Line

Hospital Domestic Cold Water Supply

Backup Line/Dead Leg

Ice Machine

Ice Machine Supply….look closely…….what is this?

?

Cross-ConnectionImproper BackflowPreventer

Inspection Items Cooling Towers

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Cross-ConnectionImproper BackflowPreventer

Inspection Items Cooling Towers

Water supply - backflow prevention Biofilm/growth Location of tower, relation to air intakes Chemical treatment program Dead legs/seasonal usage considerations Side stream devices Number of chillers/absorbers Free cooling

Case Study - Capacity vs. Usage

- Holding Tank – Tank supply to Cooling Tower bypassed direct, highly chlorinated city water feed- Low turnover in tank – frequent Legionella bacteria detected in samples

Decorative Fountains

Inspection Items Decorative Fountains

Water supply - backflow prevention Biofilm/growth Location of fountain Chemical treatment program, aeration Water turnover Proximity of seating Requires routine cleaning, water

turnover, biocide evaluation, etc.

Building Humidification

Softening Steam Generation

Humidification

Building Humidification

Inspection Items Building Humidification Water supply - backflow prevention Steam vs. water Water treatment (RO and chlorine

depletion, softening, etc.) Water quality (turnover, temperature,

quality, etc.) Pipe supply material Areas served

Other Systems

Systems to Evaluate/ Inspect…..

Dialysis Systems Dental Chairs/Lines Nebulizers/humidifiers Pharmacy/compounding Softeners Hydrotherapy/Baths And more……..

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FACILITY BEST MANAGEMENT PRACTICES

Best Management Practices

1. Perform an in-field assessment of building water systems for

Legionella risk to include

evaluating water equipment,

cross connections, dead legs,

plumbing materials, etc.

2. Develop a Legionella Water

Management Plan

3. Maintain accurate data management/records, training,

system drawings/information

Benefits of Water System Program Management

• Minimize Risk

• Improved Safety

• Reduced Operational Costs (accurate documentation, mapping)

• Improved efficiencies

• Regulatory & internal guideline compliance

Secondary Disinfection Methods

• Thermal Shock Treatment (Pasteurize)

• Shock Chlorination(>10mg/L residual)May require water tanks to be 20 to 50 mg/L

• Continuous Supplemental Chlorination (2-4 mg/L)

• Copper- Silver Ionization (continuous)

• Monochloramine

Point-of-use Filtration

Further Information

HydroCorp

5700 Crooks Road, Suite 100

Troy, MI 48098800.690.6651 | hydrocorpinc.com

Steve Fox

sfox@hydrocorpinc.com

301-741-7093