An analyst reports that the final Fecal Coliform counts have reached 23 CFU/100 mL. Which of the following BEST describes the conditions at the sampling location?

The presence of Fecal Coliform bacteria in water is an important indicator of water quality and potential contamination, particularly from domestic sources. A count of 23 CFU (Colony Forming Units) per 100 mL suggests that fecal material from warm-blooded animals, often originating from human sources or domestic wastewater, is likely present in the water.

When analyzing water quality for recreational safety, low levels of Fecal Coliform can imply a safer condition, but the acceptable count can vary based on regulations and guidelines set by health authorities. In this case, 23 CFU/100 mL indicates a significant enough presence of these bacteria to pose a concern for safety and suggests that the water is influenced by domestic wastewater.

Other options imply different conditions: claiming the water is clean or safe overlooks the significance of any detectable fecal contamination, while suggesting excessive runoff from agriculture doesn't align with the specific indication provided by Fecal Coliform counts, which are more closely tied to human and domestic waste. Thus, the finding strongly indicates contamination from domestic sources, affirming that option accurately describes the conditions at the sampling location.