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Cross Connection Control Programs and Backflow Preventers Are Essential Components Of

Safe Drinking Water Systems                   

June 18, 2004 -- The Backflow Prevention TechZone is a compendium of recent news, resources, and archived information from around the world, for those who are involved or interested in the safety of potable water distribution systems, and backflow prevention or cross connection control programs.  Backflow prevention or cross-connection control education, as well as training, for waterworks personnel, public health and municipal officials, architects, engineers, contractors, plumbers, backflow preventer testers, and students of all ages, will be the central point of a series of references and links to basic through advanced technical information about the appropriate use and correct installation of drinking water system backflow preventer devices, and why they are essential to drinking water plumbing safety and our health.   Historical to current, and beyond,  information, ideas, and techniques from around the world, related to backflow prevention and cross connection control between potable water plumbing, and drainage or non-potable systems, as well as other safe drinking water supply issues will be the primary focus of the Backflow Prevention TechZone.

  Plumbing system cross connections, which have been defined as existing or potential connections between potable or safe to drink and non-potable water supplies, water using equipment, or drainage systems, continue to be a serious potential public health hazard in 2004 worldwide.  Anywhere people congregate and utilize communal water supplies, water using equipment, and drainage systems, the danger of un-protected cross connections continue to threaten public health.  Public perception has been that widespread waterborne disease outbreaks have been controlled, but localized incidents have not yet been eliminated.  Last year's extensive US' power blackout related municipal water system pressure breakdowns, and subsequent "boil water" notifications for millions, however, have focused the intense spotlight of public attention on drinking water safety as never before.  As one recent result, there is a widening recognition that properly installed, maintained, and tested backflow prevention devices are critical elements of safe drinking water systems in our  communities and workplaces.

  Although the backflow prevention & cross connection problem thus seems a new development for many to consider, there have been numerous Barometric loop, late 1930's vintage historical, as well as ongoing recent incidents, where the backflow or backsiphonage of contaminated water through a cross connection has caused localized to extensive contamination of many communities'  or workplaces' drinking water systems.  Backflow preventer device development, beyond simple check valves, began to accelerate and diversify in the mid-20th century, but potable ("city") water piping systems and water using equipment,  especially inside industrial & medical buildings, have grown exponentially in complexity and are also continuously altered.  All too often, surveys over the decades have shown that water using devices and equipment which can contaminate a drinking water system, continue to be connected  to potable waterlines without properly selected, permitted, installed, maintained, and if appropriate for the device, tested & certified backflow preventer valves.   So, despite decades of new public health and occupational safety laws, as well as updated and revised plumbing codes, along with new improved backflow preventer devices, the cross connection problem  continues to be an ongoing dynamic one.

  The most universal backflow hazards are constantly re-created, i.e., cross-connections within residential & public washrooms, and the ordinary, unprotected  from backflow, hose connections.  The bathroom may be the location of several of our most taken for granted modern plumbing fixtures, yet it continues to be a repository of one of the subtle yet potentially dramatic backflow hazards found recurrently in our homes and public places (Toiletology 101).  Many local health departments have "blue water" flowing from the kitchen sink reports in their archives, which may well be only the tip of the iceberg of un-documented incidents of actual backflow from an un-approved or improperly installed fill-valve assembly....  

However, recent cross connection inspection surveys (USC/FCCCHR) continue to reveal that the most prevalent, potentially hazardous, potable water plumbing cross connection is the common hose connection (or hose bibb) (UF/IFAS, 3/95) found in virtually every  home and building with a water system. The following link to the ABPA - American Backflow Prevention Association's  Buster Backflow comic book, for students of all ages, however, may thus best illustrate the starting point for any backflow prevention or cross connection control program.  A comprehensive primary can be explored in the Backflow Introduction presented at the USC-Foundation for Cross-Connection Control and Hydraulic Research.   Here in Michigan, local municipalities have been implementing cross connection control programs since about 1972, some even earlier.  Most initially focused only on industrial, commercial, and institutional facilities, and the plumbing cross connection hazards found in such premises.  More recently, locally enforced programs encompassing residential inspections, even single family homes, have brought the struggle for cross connection control and backflow prevention home to millions of residents where they live............

Usually working behind the scenes as far as the general public is concerned, several organizations have been very active in  responding to, promoting, and widening the scope of public awareness and education about backflow prevention and the cross-connection control problem in drinking water systems. They deserve a large share of the credit (while not diminishing the contributions of the many active State & municipal programs) for where we are today, with safe drinking water mostly being taken for granted in the USA and other countries.....

  American Backflow Prevention Association (and many local chapters)

 ABPA's ALL NEW Discussion Forum, reformatted to easily find discourse on current issues and topics...

            ABPA's Previous Backflow Prevention Discussion Forum, current issues and topics (going off-line June 21st)......

  American Society of Sanitary Engineering  

  American Water Works Association  (search for "backflow")

  University of Florida Treeo Center

    University of Southern California Foundation For Cross-Connection Control And Hydraulic Research

Well coverings are the first known "backflow prevention" devices for water systems..Backflow Related Historical DocumentsWell coverings are the first known "backflow prevention" devices for water systems..
The History of Plumbing, Drinking Water,

Backflow Prevention, and Cross Connection Control

a Collection Including

Pre-Historic Practices to Modern Public Health Laws,

Plumbing, Building, and Related Codes

NYC street excavation around the early 1900's,  at a cross-connection investigation / archeological site??

Plagues & Epidemics....Perhaps the first backflow incident?..A must read summary of why backflow prevention & cross connection control programs and efforts are essential.  Plumbing & Mechanical Magazine, July 1988 at

The History of Plumbing - Babylonia    Plumbing & Mechanical Magazine, July 1989 at

  Egypt     P & M Magazine, July 1989 at

 Crete       P & M Magazine, July 1989 at

 Greece     P & M Magazine, July 1989 at

  China      (Reuters) Beijing July 26, 2000 - at

 Jerusalem   P & M Magazine, July 1989 at

  Pompeii    P & M Magazine, July 1989 at

 Roman and English Legacy   P & M Magazine, July 1989 at

A History of Plumbing Engineering, P & M Engineer, 06/09/2000

 America.........Plumbing & Mechanical Magazine, July 1987 at

California....... The High Pressure Water System, Oct. 1925, Museum of the City of San Francisco

Brief History of Drinking Water, American Water Works Association

Historic Milestones in Drinking Water History, Alaska Div. of Environmental Health 

 Evolution of Plumbing, at

History In-The-Making, Recent Centuries Ongoing Facts, Figures,

Incidents, and Events in Backflow Prevention & Cross Connection Control:

 One Hotel's unprotected Cross Connection with a sewer allowed Entomoeba histolytica to become the agent for a dramatic backflow incident at the Chicago World's Fair in 1933...1000 cases of severe illness and 58 deaths....FDA Foodborne Pathogenic Microorganisms and Natural Toxins 1992 (Bad Bug Book)

 Two instances of ethylene glycol intoxication due to contamination of water systems' cross-connections,  CDC's MMWR, 36(36);611-4

 15 Responsibilities, a Cross-connection Control Supervisor's Checklist, by Les O'Brien, CET

 25 Facts about Water, AWWA

 49 students seriously ill  with methemoglobinemia attributable to nitrite contamination of potable

       water through boiler fluid additives. Defective backflow preventer source of the  cross-connection, CDC's MMWR, 46(09);2202-204

 50 Cross-Connection Questions, Answers, & Illustrations Relating to Backflow Prevention Products & Protection of Safe Drinking Water Supply, Watts (1.8m pdf download)

  52 Backflow Preventers'   Typical Installation Drawings, Zurn-Wilkins

  64 Backflow "incidents" and recent articles, ABPA

  81 Dangerous Cross-Connections,  U of M Engineeering Bulletin, 1943

  5000 Lawn sprinkler systems to be inspected each year,  as Oakland County Michigan "Commission cracks down on sprinklers ",

Oakland Press 6/25/03

  Backflow Prevention Program Customer Brochure, Sydney Australia Water (886k pdf file),  Information here  is usefull for everyone.

  Outer Space   NASA , May 2001 at

  Report on Main Breaks.... Water distribution system safety issues discussed -- Museum of the City of San Francisco

TechZone Departments

Backflow Prevention & Cross-Connection Control Basics, Waterborne Diseases, and Chemical Contaminents

Industrial Backflow and Cross Connection Incidents, Florida Dept. of Environmental Protection

Municipal Backflow Prevention and Cross Connection Control Programs

   Backflow Prevention Education / Training Programs and Resources

 State, Provincial, or Regional Backflow Prevention & Cross Connection Control Regulations

National Backflow Prevention and Cross Connection Control Policies

Government Agencies' and Universities' related to Backflow Prevention & Water Quality Issues

Backflow Prevention and Cross-Connection Control Related Associations, Foundations and Networks

 Backflow Prevention and Cross-Connection Control Articles & References

Backflow Prevention Device Testing, Certification, Survey Education Issues, and Resources

Cross-Connection Control and Backflow Prevention Glossaries & Definitions


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