BACKFLOW PREVENTION

AND

CROSS-CONNECTION CONTROL

1

1

DEFINITIONS

BACKFLOW – The undesirable reverse flow of water in a public water system.

BACKFLOW PREVENTER (BFP) – A device designed to prevent the reverse flow of water in a water system.

DOUBLE CHECK VALVE (DCV) – A backpressure type backflow prevention device designed for continuous or intermittent pressure, including backpressure, where pollutants may be involved.

DOUBLE DETECTOR CHECK (DDC) – A backpressure type backflow prevention device designed to serve also as a detector check on a fire protection system where pollutants may be involved. Including a line-sized approved (DCV) backflow preventer and a three-quarter approved (DCV) backflow preventer on the metered bypass side.

DUAL CHECK (DUC) – A backpressure type backflow prevention device designed especially for containing residential areas where pollutants only may be involved.

INTERMEDIATE ATMOSPHERIC VENT – A backpressure and back siphonage type backflow prevention device designed to operate under continuous pressure, including backpressure, where “low degree of hazard” contaminants may be involved.

REDUCED PRESSURE ZONE (RPZ) – A backpressure and back siphonage type backflow prevention device designed to operate under continuous pressure, including backpressure, where contaminants may be involved.

REDUCED PRESSURE ZONE DETECTOR CHECK (RPDC) – A backpressure and back siphonage type back flow prevention device designed to serve as a detector check on fire protection system where contaminants may be involved. It includes a line-sized reduced pressure zone backflow preventer with a metered by-pass, into which has also been incorporated an approved reduced pressure zone backflow preventer.

BACKFLOW PREVENTION – Actions designed to discover, eliminate, and prevent backflow and uncontrolled cross-connections.

BACKFLOW PREVENTION BY CROSS-CONNECTION CONTROL – Installation of a backflow control device at each cross-connection on a premises. (The First Line of Defense.)

BACKFLOW PREVENTION BY CONTAINMENT – The installation of a backflow prevention device at the service connection to the premises in order to protect the public water supply main only. (The Second Line of Defense.)

1

BACKPRESSURE – An increase in pressure in a Customer’s water system to a level above that of the public water system generally caused by pumps, thermal expansion, or reasons other than a reduction or loss of incoming pressure. Backpressure is generally more evident in a closed water system.

BACK SIPHONAGE – A reverse flow in a water system caused by a reduction in pressure in the public water system. Back siphonage is generally more evident in an open water system.

CERTIFIED TESTER – One who has successfully completed an approved training course on the proper techniques of testing backflow devices. This certification is mandatory under the AWWA Manual M-14 for Backflow Prevention. Testers must be periodically re-certified as required by law.

CLOSED WATER SYSTEM – Water System with a checking device installed at the service connection. A check valve, backflow preventer or pressure-reducing valve would create a closed system.

CONTAMINANT – Any substance that, if introduced into the potable water system, could create a health hazard.

CROSS-CONNECTION – A physical arrangement whereby a public water supply is connected, directly or indirectly, with any other water supply system, sewer, drain, conduit, pool, storage reservoir, plumbing fixture, or other device which contains or may contain contaminated water, sewage or other liquid of unknown or unsafe quality which may be capable of imparting contamination to the public water supply as the result of backflow. By-pass arrangements, jumper connections, removable sections, swivel or changeable devices, and other temporary or permanent devices through which backflow could occur are considered to be cross-connections.

CROSS-CONNECTION, NON PRESSURE TYPE – A low inlet installation where a potable water pipe is connected or extended below the overflow rim of a vessel, that contains a non-potable fluid at atmospheric pressure.

CROSS-CONNECTION, PRESSURE TYPE – An installation where potable water pipe is connected to a closed vessel, or a piping system, that contains non-potable fluid and is above atmospheric pressure.

CUSTOMER’S WATER SYSTEM – All potable water piping, valves, fittings and appurtenances on the Customer side of the service connection.

HAZARD, DEGREE OF – The range in danger or potential danger to health, due to contaminants entering the potable water system via an uncontrolled cross-connection, which can be classified from mildly toxic to lethal.

IMPURITIES – Objectionable or dangerous substances introduced into the potable water system.

INSPECTOR – An individual qualified and authorized to make inspections, interpret codes, regulations and procedures related to Backflow Prevention.

1

OPEN WATER SYSTEM – A Customer water system with no checking devices installed in the service pipe. Water from the Customer’s system is free to backflow into the main for whatever reason.

POLLUTANT – Any substance that, if introduced into the potable water system, could be objectionable but would not create a serious health hazard.

POTABLE (WATER) – Any water that is safe for human consumption.

PUBLIC WATER SYSTEM – A water system (including but not limited to supply, treatment, transmission, and distribution facilities and appurtenances) operated as a public utility that supplies potable water to the service connection of the Customer’s water system (herein defined as the City of LaGrange water distribution system).

SERVICE CONNECTION – The point of delivery of water to a Customer’s water system, the normal location of the meter. It is the end of the public water system and the beginning of the customer’s water system.

VACUUM BREAKER (VB) – A Back siphonage prevention device that uses atmospheric pressure when the system pressure drops below an acceptable level. It is designed for use where the receptacle or the environment being served is subject to atmospheric pressure only.

VACUUM BREAKER, ATMOSPHERIC TYPE (AVB) – A vacuum breaker designed for use under flow conditions not to exceed twelve (12) consecutive hours and where it will be subject to no static pressure and no backpressure.

VACUUM BREAKER, PRESSURE TYPE (PVB) – a vacuum breaker designed to operate under continuous pressure and flow, but no backpressure.

VACUUM BREAKER, HOSE TYPE (HVB) – A vacuum breaker designed for hose connections only, but not for continuous pressure.

VACUUM RELIEF VALVE – A device to limit the degree of vacuum in a vessel or pipe, but not for use in cross-connection control.

1

a)

TYPICAL BFP VAULT INSTALLATION DETAIL

TYPICAL BFP METER BOX INSTALLATION DETAIL

SECTION VIIITESTING AND MAINTENANCE

  1. All backflow prevention devices shall be maintained in a safe condition and in good working order.
  2. The Customer shall be responsible for the cost of testing, maintenance and repair of all backflow prevention devices connected to his/her water system. The City currently provides, installs, and maintains DUC protection for standard residential and small commercial ¾” services. The customer is responsible for backflow protection on larger or more hazardous service connections.
  3. Tests must be done in accordance with the lesser of the following schedule, manufacturer’s instructions, or State or Federal law:
  1. Air Gap – annually
  2. PVB – annually
  3. DUC – changed out by City when meter is replaced
  4. DCV – annually
  5. RPZ – annually
  1. Test procedures for all devices shall be as outlined by the Manufacturer, AWWA Manual 14, and other references discussed in this document.
  2. Testing must be performed by an individual who is certified and trained to understand the design and intended operation of the BFP being tested. Test results shall be sent to the City and contain the following information:
  1. Name and address of facility
  2. Name of certified tester
  3. Device type, manufacturer, model, size, serial number
  4. Date of installation
  5. Date of test
  6. Test results
  7. Repairs made

SECTION IXFIRE PROTECTION

  1. Fire protection systems are broken down into six classes as defined in AWWA Manual 14:
  2. Class 1 - DDC Assembly - Direct connection to the public water system with no pumps, tanks, other supply sources, antifreeze or additives. Sprinkler drains are discharging to atmosphere, dry wells, or other safe outlets. A fire department pumper connection may be provided on the customer side of the DDC.
  3. Class 2 – DDC Assembly – Class 1 except customer owned booster pumps might be installed from the public water system. A fire department pumper connection may be provided on the customer side of the DDC.
  4. Class 3 – DDC Assembly – Class 1 plus an elevated storage tank, fire pump with covered reservoir, and/or pressure tank.
  5. Class 4 – RPZ Assembly – Class 1 plus an auxiliary pumper connection to an auxiliary supply located on the premises.
  6. Class 5 – RPZ Assembly - Class 1 plus an auxiliary supply such as a pump with a reservoir exposed to contamination, or where antifreeze or other chemical additives are used.
  7. Class 6 – RPZ Assembly - Combined industrial process and fire protection systems on the same service line (this is not an approved configuration on the City of LaGrange system) with or without storage tanks or pumps.
  1. The BFP shall match the size of the required fire line connection.
  2. The metered bypass line on the DDC shall be a ¾” copper pipe and include a bronze detector meter and a ¾” DCV BFP.
  3. The device and valve bodies shall be equivalent to cast iron, coated inside and out with FDA approved fused epoxy coating and assembled with corrosion resistant bolts. All other components shall be of bronze or equivalent corrosion resistant materials.
  4. The BFP shall not be buried in earth but installed below ground in a concrete or other approved vault and as close as practical to the property line of the premises.
  5. Note: Under no circumstances should a domestic or other non-fire related tap be made on the fire line system.


FIRE LINE BACKFLOW PREVENTER

DDC VALVE ASSEMBLY

TYPICAL DETAIL

1

TEST & MAINTENANCE REPORT

BACKFLOW PREVENTION ASSEMBLIES

NAME OF PREMISE:

STREET ADDRESS:

LOCATION OF DEVICE:

SERVICE: POTABLE FIRE IRRIGATION OTHER

Manufacturer: Model: Serial No.: Size:  RP  DC  PVB  AVB  AG

PRESSURE DROP ACROSS FIRST CHECK VALVE PSI

CHECK VALVE #1 / CHECK VALVE #2 / DIFFERENTIAL PRESSURE RELIEF VALUE / PRESSURE VACUUM BREAKER
INITIAL TEST / 1. LEAKED 
2. CLOSED TIGHT / 1. LEAKED 
2. CLOSED TIGHT / OPENED AT LBS.
DID NOT OPEN / AIR INLET OPENED AT
PSI
DID NOT OPEN
R
E
P
A
I
R
S / CLEANED / CLEANED / CLEANED
REPLACED: / REPLACED: / REPLACED: / CHECK VALVE: PSI
RIBBER PARTS KIT / RIBBER PARTS KIT / RIBBER PARTS KIT / LEAKED
C. V. ASSEMBLY / C. V. ASSEMBLY / C. V. ASSEMBLY
OR / OR / OR / CLEANED 
DISC / DISC / DISC
O-RINGS / O-RINGS / O-RINGS / REPLACED:
SEAT / SEAT / SEAT / C. V. ASSEMBLY
SPRING / SPRING / SPRING / DISC. AIR INLET
STEM/GUIDE / STEM/GUIDE / STEM/GUIDE / DISC. C. V. 
RETAINER / RETAINER / RETAINER / SPRING
LOCK NUTS / LOCK NUTS / LOCK NUTS / RETAINER
OTHER / OTHER / OTHER / GUIDE
O-RING
OTHER
FINAL TEST / CLOSED TIGHT / CLOSED TIGHT / OPEN AT LBS
REDUCED PRESSURE / SATISFACTORY

NOTE: ALL REPAIRS/REPLACEMENT SHALL BE COMPLETED WITHIN TEN (10) DAYS.

REMARKS:

I HEREBY CERTIFY THAT THIS DATA IS ACCURATE AND REFLECTS THE PROPER OPERATION AND MAINTENANCE OF THE UNIT.

CERTIFIED TESTING COMPANY:

INITIAL TEST BY: CERTIFIED TESTER NO. DATE:

REPAIRED BY : DATE

1

FINAL TEST BY: CERTIFIED TESTER NO. DATE:

1

AIB 010 Rev 9-24-2015

1