At what point is backflow testing typically required?

Backflow testing is typically required on a routine basis as dictated by local regulations. This is because backflow prevention devices are critical for maintaining safe drinking water and preventing contamination from non-potable sources. Local health and plumbing codes often mandate that these devices be tested regularly to ensure they are functioning properly.

Routine testing can help identify any failures or malfunctions in backflow prevention systems before they lead to serious problems, such as water contamination events. The specific frequency of testing can vary by jurisdiction, but regular monitoring is crucial for maintaining public health standards related to water quality.

On the other hand, the other options suggest testing is only necessary under specific circumstances, which does not align with the proactive approach many local regulations take to safeguard water systems.