A Cross-Connection is a. water system and a nonpotable CROSS-CONNECTION CONTROL BACKFLOW PREVENTION CROSS-CONNECTION CROSS-CONNECTION

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CROSS-CONNECTION CONTROL

and

BACKFLOW PREVENTION

Les O’Brien, UF/TREEO Center

CROSS-CONNECTION

is any connection between a potable water system and any source of contamination through which contaminated water could enter the potable water system.

CROSS-CONNECTION

A Cross-Connection is a

b

bl

LINK

between a potable

water system and a

non-potable system.

POTENTIAL CROSS-CONNECTION

Situations in which some of the

diti f ti

conditions for a cross-connection exist, but require something else to be done to complete the

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BACKFLOW

is the flow of any water,

f

i

li

id

foreign liquids, gases, or

other substances back into

a potable water system.

BACKFLOW

The Reversal of the

l di

i

f fl

normal direction of flow.

BACKPRESSURE

is a condition in which the foreign substance is forced foreign substance is forced into a water system because it is under higher pressure than the system pressure.

BACKPRESSURE

The customer’s pressure

i

h

l

is greater than the supply

pressure.

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BACKSIPHONAGE

is a condition under which the water system pressure is less

th t h i ( )

than atmospheric (vacuum), and the foreign substance is essentially sucked into the potable water system.

BACKSIPHONAGE

Backflow caused by negative

d d i th

or reduced pressure in the supply piping.

BACKSIPHONAGE

Backflow caused by negative

d d i th

or reduced pressure in the supply piping.

CONTAINMENT

SERVICE

PROTECTION

Chapter 1 METER TO CUSTOMER

ISOLATION

INTERNAL

PROTECTION

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Chapter 1 TOXIC CONTAMINANT NON-TOXIC POLLUTANT HIGH HAZARD HEALTH HAZARD LOW HAZARD NON-HEALTH HAZARD Chapter 1

PURVEYOR

The supplier / owner

of the public water

supply.

Chapter 1

CASE HISTORIES

• 1933 Chicago World’s Fair

1969 H l C C ll

• 1969 Holy Cross College, Worcester, MA • 1976 Chattanooga, TN • 1988 Belle Glade, FL DEVICE 2 3 4 1 2 3 4 ASSEMBLY

ATMOSPHERIC

VACUUM

BREAKER

(A.V.B.)

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AIR INLET CHECK CHECK NORMAL FLOW ATMOSPHERIC VACUUM BREAKER NORMAL FLOW AIR AIR ENTERS BACKSIPHONAGE ENTERS BACKPRESSURE CAUSES AIR INLET TO STICK Atmospheric Pressure Minimum of 6” above highest outlet

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ATMOSPHERIC VACUUM BREAKER

No Valve Downstream No Backpressure

i l i li i

Single Fixture Application

Non-Continuous Use

Turn off every 12 - 14 hours

Should be Inspected Annually

Summary of Applications for Backflow Protection

AVB PVB DCVA RP AG BACKSIPHONAGE X HAZARDHIGH BACKSIPHONAGE BACKPRESSURE X LOW HAZARD HIGH HAZARD LOW HAZARD

PRESSURE

VACUUM

BREAKER

(P.V.B.)

CRITICAL CANOPY OUTLET VALVE TC #2 LEVEL INLET VALVE TC #1 PRESSURE VACUUM BREAKER CANOPY OUTLET VALVE TC #2

AIR INLET VALVE

CRITICAL INLET VALVE TC #1 CHECK VALVE LEVEL PRESSURE VACUUM BREAKER

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OUTLET VALVE TC #2 INLET VALVE TC #1 OUTLET VALVE TC #2 AIR ENTERS TC #1 BACKSIPHONAGE TC #2 Air Inlet stuck closed INLET VALVE TC #1 backpressure

PRESSURE* VACUUM BREAKER Protects against backsiphonage

ONLY!

CL must be 12 “ above downstream use CL must be 12 above downstream use

Must be tested at least once a year

* CONTINUOUS PRESSURE

AVB PVB DCVA RP AG X X HAZARDHIGH BACKSIPHONAGE BACKSIPHONAGE X X HAZARDLOW HIGH HAZARD BACKPRESSURE LOW HAZARD

DOUBLE

CHECK VALVE

ASSEMBLY

(D.C.V.A.)

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1 2 3 4 Outlet valve closed CV #1 CV #2 Outlet valve opened

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DCVA Installation

• There is no height requirement • Assembly should be easily and safely

accessible.

• Installation should conform to OSHA Regulations

• DCVA installed on low hazard ONLY!

DOUBLE CHECK VALVE ASSEMBLY

Protects against Low Hazard ONLY! Both springs same, > or = to 1.0 psi Both springs same, > or to 1.0 psi

Must be tested at least once a year Maximum pressure drop - 10 psi.

Used on some Fire Sprinkler Systems

AVB PVB DCVA RP AG

X X HAZARDHIGH

BACKSIPHONAGE

BACKSIPHONAGE X X X HAZARDLOW HIGH HAZARD BACKPRESSURE X HAZARDLOW DCDA

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REDUCED PRESSURE PRINCIPLE

= RP

BACKFLOW PREVENTION ASSEMBLY

= RP

1 3 4 2 100 psi 100 psi 95 psi

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94 psi

100 psi 95 psi

94 psi

100 psi 100 psi

DUMPS THE ZONE

SPITS

DRIPS STEADILY 100 psi 95 psi 1 3 4 CV 1 Leaks 100 psi p 95 +2 2

100 psi 95 psi 105 psi

Backpressure

95 100 psi

+2

p 100 psi 95 psi 105 psi

Backpressure and CV 2 fails 98+ +2 100 psi p

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REDUCED PRESSURE PRINCIPLE ASSEMBLY Protects against High Hazard, Backpressure & Backsiphonage

RV > or = to 2.0 psi

CV #2 > or = to 1.0 psi

Must be tested at least once a year RV Vent 12 to 36 inches above grade

CV #1 3.0 psi > RV opening

AVB PVB DCVA RP AG X X X HEALTH HAZARD BACKSIPHONAGE AVB PVB DCVA RP AG X X HAZARDHIGH BACKSIPHONAGE X BACKSIPHONAGE X X X NON-HEALTH HAZARD X HEALTH HAZARD BACKPRESSURE X X NON-HEALTH HAZARD BACKSIPHONAGE X X HAZARDLOW HIGH HAZARD BACKPRESSURE X HAZARDLOW X X X X

AIR

GAP

2 times the I.D. of the supply pipe or

Minimum of 1 inch.

Flood Rim

AIR GAP

AVB PVB DCVA RP AG HIGH HAZARD BACKSIPHONAGE X X X X BACKSIPHONAGE LOW HAZARD HIGH HAZARD BACKPRESSURE LOW HAZARD X X X X X X X X X X

WHAT SINGLE ITEM AT HOME CAUSES OVER HALF OF THE CROSS-CONNECTION

ACCIDENTS IN THIS COUNTRY?

The Common Garden Hose

Would you let your children drink from a hose that you just used to clean out your sewer line?

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Backflow Incidents

The problems: WHY CROSS-CONNECTIONS EXIST: • unaware of problem • convenience • inadequate devices

Inadequate Education and Training:

• Engineers & Architects • Contactors

• Inspectors • Health officials • Customers

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Plumbing Codes (IPC)

• Code only refers to new construction • Annual testing required only on g q y

approved, testable assemblies

• Backflow devices cannot be tested • There are no testing and maintenance

requirements for backflow devices

What are the odds that a backflow incident will

happen in your community? We need: ti backflow and a

Sometimes Murphy helps out.

cross-connection

Murphy's laws

If anything can go wrong, If anything can go wrong,

it will. it will.

If there is a possibility of If there is a possibility of several things going wrong, several things going wrong, the one that will cause the the one that will cause the most damage will be the one most damage will be the one

to go wrong. to go wrong.

If anything just cannot

go wrong, it will anyway.

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Left to themselves,

things tend to go from

bad to worse.

Quantization Revision of Quantization Revision of Murphy's Laws Murphy's Laws Everything goes Everything goes wrong all at once. wrong all at once.

How many water main breaks happen each day?

Gainesville has 45,000 metered customers and 1000 miles of water

i mains.

Gainesville averages 2 water main breaks each day.

That is…

2 neighborhoods each day that experience a drop in pressure.

BACKFLOW

Now, all we need is that cross-connection.

What single item at home causes the most backflow

incidents?

The common

Garden Hose

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Commercial products:

• There are dozens of products available to

the public

• These products can create a

cross-connection connection

• These products do not have warning

labels

• There is no control over the manufacture

and sale of these dangerous products

Commercial products:

the public

labels

Commercial products:

the public

labels

Commercial products:

the public

labels

and sale of these dangerous products.

Let’s look at some of the products the uneducated public purchase and then public purchase and then

connect to their garden hose.

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NO AIR AIR GAP

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Refill Your Dog’s Water Bowl Automatically!

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AIR GAP

NO AIR GAP

Maybe a little public education would help.

More Information: http://www.abpa.org

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The topic for the next “Buster”

may focus on may focus on reuse water for

homeowners.

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GIL0 0 3 0 2 1 4 2 3 75 14 2 2 1 19 1 6 6 22 42 47 43 6 1 4 2 16 Number of UF/TREEO Backflow Testers in each County BRAD GL BRAD GIL 55 18 6 11 6 31 86 4 2 2 0 3 4 0 2 0 3 0 2 1 4 2 3 75 14 2 1 ₁ 6 88 76 2 14 135 2 2 29 81 17 6 14 32 18 40 1 16 Number of UF/TREEO Backflow Testers in each County 17 2 14 2 14 55 1 0 11 58 1 2 48 2 0 29 81 16 Number of UF/TREEO Backflow Testers in each County 38 41 34 73

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57 7 1 1 1 2 3 1 1 1 Also: Jackson – 1 Duval – 1 Number of ASSE Backflow Testers in each County 146 19

FS/AWWA Endorsed Backflow Tester Training Organizations

1. UF/TREEO Center

2. Florida Water and Pollution Control A i ti (FW PCOA)

Association (FW-PCOA)

3. the Florida Plumbing Apprenticeship School in West Palm Beach

4. ICCC in Hollywood 5. MTI

Potential Contamination Due to Cross-Connections and Backflow and the Associated

EPA White paper:

Backflow and the Associated Health Risks http://www.epa.gov/safewater/tcr/pdf/ccrwhite.pdf Prevalence of Cross-Connections in Household Plumbing Systems http://www.usc.edu/dept/fccchr/epa/hhcc.report.pdf