Case Histories of Backflow Accidents

These cases are not even a small amount of those reported. Cases date back from the early 1900's and would fill a Dallas phone book.

1. April 1923: Oakland, Ca. Fire dept. pumped salt water into public water
2. July 1925: Winona Lake, In. Cross-connection between town mains and contaminated lake.
3. Dec. 1942: San Francisco, Ca. Ship fire system backpressured salt water into City system.
4. Mar. 1944: Elizabethtown, Ky. Backsiphonage through frost-proof toilets into City water.
5. Aug. 1969: Worcester, Ma. Holy Cross School.THIS IS A FAMOUS CASE! 83 football team members/coaching staff stricken with infectious hepatitis via sunken hose-bibs. Chemicals had been applied to the grounds and watered. There was a fire across town which caused a backsiphonage sucking this water into the hose bibs and into the water lines at the school. The team and staff drank out of the water fountain after practice and came down with hepatitis. This could have easily been prevented with a backflow preventer.
6. Sept. 1969: Peoria, Il. Sodium Arsenate backsiphoned from a tank of weed killer on a farm into the public water supply.
7. July 1970: San Bruno, Ca. Strong detergent from a car wash pumped through a single faulty check into city main.
8. Dec. 1974: San Antonio, Tx. Chemically treated steam backpressured into potable system through faulty check valve.
9. Oct. 1977: San Antonio, Tx. "Black water" from fire sprinkler polluted major portion of hospital complex.
10. July 1978: San Antonio, Tx. Backsiphonage of 'blue water' from toilet in residence without a vacuum breaker into the city water. There have been cases of this reported each year in San Antonio!
11. Mar. 1985: New York, NY. Hospitalized woman died after being exposed to Ethyl Glycol while undergoing Hemodialysis. Backpressure from air conditioning system.
12. Sept. 1987: San Antonio, Tx. Non potable water from heat exchanger backpressured thru faulty check valve in ten story building. Numerous illnesses reported.
13. Mar. 1989: San Antonio, Tx. Diesel fuel at an asphalt manufacturing plant backpressured into internal water system. The service connection to the city water was protected by an RP.
14. Jan. 1991: San Antonio, Tx. Water from heat exchanger in office building backpressured through unprotected make up connection. The city system was protected by an RP.
15. Feb. 1991: Fountain Valley, Ca. Compressed air used for dental equipment backpressured into building water supply.
16. Aug. 1993: Superior, Az. Backflow of antifreeze solution thru fouled single check valve on fire sprinkler system at arboretum.

    Then there are the somewhat funny cases of the winery that had one of its vats backflow into the city water lines giving the town wine tasting water. The candy factory that its chocolate vat backflowed into the city water turning everyones water to brown and sweet. The list is almost endless. All of these cases could have been prevented with proper preventers and /or maintenance of existing preventers.