A double check valve assembly that shows equal pressure between the check's inlet and outlet indicates what condition?

When a double check valve assembly shows equal pressure between the check's inlet and outlet, it indicates a potential failure of one or both check valves. In a properly functioning double check valve assembly, the pressure on the inlet side is typically higher than on the outlet side due to the check valves preventing backflow. Equal pressure suggests that these check valves may not be sealing correctly, which can lead to backflow conditions that compromise the water supply.

In contrast, if the pressure was within acceptable limits or backflow protection was functioning correctly, one would expect a distinct pressure differential. Water quality being compromised also does not directly correlate with this pressure observation; it is more focused on the performance of the check valves themselves. Thus, the observation of equal pressures points directly to a failure of the check valves, confirming the answer choice related to that condition.