A direct connection during firefighting efforts was responsible for contaminating a portion of Pittsburg in 2008. Two pumper trucks were connected to fire hydrants. The backpressure caused by the trucks overtook the city water pressure and forced the foam solution into the city’s culinary lines. Soapy water complaint calls alerted authorities to a problem. All of downtown Pittsburg could not use water until the foam was flushed from the system.
An indirect connection caused a resident to make several calls to the water company to complain about water related family illnesses with bacteriological infection. This prompted a boil water order for all 441 residents of a small Louisiana town. The customer blamed the city water supply and complained to the health department. The health department’s investigation found that the contamination was backsiphonage from the complainant’s very own swimming pool. A hose was repeatedly left hanging over the side of the pool and into the water. The customer admitted she had noticed siphoning from the pool on occasions. An airgap would have prevented this incident.