Backflow Incidents

Backflow Prevention Helps Protect Our Drinking Water

Backflow incidents in recent years like the ones below can threaten public health. As a community, our efforts to control cross-connections and to prevent backflow help keep our San Diego County water supply safer and more secure. When installed properly and maintained routinely, backflow preventers reduce the risk of water-borne health problems. While incidents of backflow do occur, they are happening less frequently. Click on dates for full stories, and please let us know if any links are broken.


September 12, 2017

Alameda, CA
Residents and businesses at Alameda Point complained about the look and taste of their water. The Water District found a cross-connection between the drinking water system and a non-potable irrigation well. The City issued a Do Not Drink / Do Not Use order for 268 residents and over 60 businesses over several days. Samples from the irrigation well contained elevated levels of total coliform bacteria with no measurable disinfectant, but did not contain any e. coli bacteria. The Water District permanently disconnected the well.


December 14, 2016

Corpus Christie, TX
City-wide water use ban issued when asphalt plant workers reported brown, milky, sudsy water on several occasions. After multiple efforts by city crews to flush contaminated water out of pipes, it was found that there was no backflow preventer between the potable water supply and the chemical mixing tank. Water testing at various points around the city revealed no contamination beyond the asphalt plant.


November 2, 2016

Culpeper, VA
Backflow of Antifreeze from the fire sprinkler system of a business leads to water distribution system flushing. Residents warned not to drink or cook with the water even though the propylene glyco antifreeze is non-toxic.


August 4, 2016

Jacksonville, NC
Faulty backflow prevention device allows swimming pool water to contaminate drinking water lines. Boil water advisory issued while water district flushed lines and the backflow preventer was replaced.


July 28, 2015

Corpus Christi, TX
E-coli found in the city water was traced to a neighborhood of properties which have private wells and sprinkler systems without backflow prevention assemblies. Contaminated water was able to flow into the community water system from these properties because there was no backflow protection maintained between them and the water district.


July 21, 2012

Lubbock, TX
Power Outage leads City Officials to issue boil water order.  Loss of power crippled water distribution pumps, resulting in low pressure and potential for backflow of contamination or pollution into the drinking water supply


June 1, 2011

Somerset, Mass.
Hydro-Seeding Contractor direct connects to fire hydrant, pumping seed material and chemicals into water main, poisoning City drinking water system

See also: The Herald News


May 29, 2010

Saratoga Springs, Utah
Illegal Cross Connections are the probable cause of a Bacteria Outbreak

See also: utahcountyonline.org


August 31, 2009

Lenexa, KS
Failure of Restaurant's Soda Machine Backflow Preventer was suspected of sickening customers
Update: Backflow Preventer failure ruled out. Former employee of Mi Ranchito Restaurant pleads guilty to charges of intentionally poisoning customers


June 15, 2009

Boise, ID
Four Residents sickened due to faulty Backflow Devices; 120 people affected.

See Also: Boil Water Advisory


June 3, 2009

Anson County, NC
Cross Connection through Fire Hydrant affects about 300 people with contaminated water


August 22, 2007

Chula Vista, CA
Eastlake Business Park tenants learn of Reclaimed Water flowing in Potable Pipes