What is TCEQ's preferred method for backflow prevention when health hazards are present?

TCEQ's preferred method for backflow prevention when health hazards are present is the air gap. An air gap provides the highest level of protection against backflow and contamination of the potable water supply. This method creates a physical separation between the water supply and any potential contaminants.

In situations where there is a risk of severe health hazards—such as chemicals, biological contaminants, or other pollutants entering the drinking water—an air gap effectively prevents any possibility of backflow, since there is no direct connection between the contaminated source and the potable water system.

While other devices, like reduced pressure principle devices and fixed vacuum breakers, offer significant protection and are suitable for certain applications, they do not provide the same level of safety as an air gap in situations involving health hazards. A dual check valve is typically used for less critical applications and does not meet the stringent requirements for high-risk scenarios. Therefore, the air gap stands out as the most reliable and safest method in such instances.