Final answer:
A + TC sample, indicating a positive test for total coliforms, must be resampled as soon as possible, usually within 24 hours, to confirm contamination and ensure public health safety.
Step-by-step explanation:
The question "How soon must a + TC sample be resampled" refers to the protocol that must be followed when a water test yields a positive result for total coliforms (TC). In the context of water quality testing and health safety standards, it is essential to act swiftly.
The Environmental Protection Agency (EPA) recommends that a resample should be taken as soon as possible, typically within 24 hours, to confirm the presence of contamination. Immediate resampling helps to determine whether the positive result was due to an actual contamination issue or a sampling error.
It is critical for protecting public health, as total coliforms can be an indication of the presence of harmful pathogens in the water supply.