In the context of water quality, high fecal coliform levels typically indicate:

High fecal coliform levels in water are a significant indicator of contamination, primarily suggesting the presence of fecal matter from warm-blooded animals, including humans. This contamination directly correlates to the potential introduction of pathogens that can pose serious health risks to humans who come into contact with or consume the contaminated water. Fecal coliform bacteria serve as a useful indicator organism because their presence indicates that other harmful microorganisms that cause waterborne diseases may also be present.

High levels of fecal coliform do not signal clean and safe water sources, nor do they indicate effective water treatment processes. In fact, they often prompt further investigation and monitoring to evaluate the safety of the water supply and to identify the points of contamination. Thus, acknowledging the presence of fecal coliform is critical for public health and safety, underscoring why this is the correct answer.