Here’s a true event reported by the Texas Commission on Environmental Quality: While mixing a batch of pesticide, a worker pushed a garden hose into the tank until it touched the bottom. Nearby, city utility workers opened a flush valve, releasing a large flow of water from a water main. Where the worker was mixing the pesticide, the water pressure dropped, and the flow in the hose reversed. Water and pesticides flowed from the pesticide tank back through the hose and into the water lines of the residence.
Fortunately, the worker mixing the pesticide realized the danger and alerted the utility workers, who closed the flush valve before the contamination reached the city’s distribution line. Still, good water and time were wasted.
The solution to this risk is to have a backflow preventer installed. TCEQ requires homeowners with external hose bib connections, irrigation systems and most commercial buildings to have one. Regular tests and inspections insure that your household plumbing and the public supply is protected.
Residents should install backflow devices on hoses bibs. Especially those used for drip irrigation or hose head sprinklers. The same opposite flow can occur if there is a drop in pressure. These hose backflow preventers are simple, inexpensive devices that provide the same protection.