What is the EPA stream water quality standard for fecal coliform?

The EPA stream water quality standard for fecal coliform is set at a threshold to help ensure safe water practices and protect public health, especially in areas where water is used for recreation or as a drinking water source. The correct standard, which is 2 colonies per 1 ml, is established based on the understanding that higher concentrations of fecal coliform bacteria can indicate the presence of harmful pathogens, suggesting that the water may be contaminated with fecal matter from animals or humans.

Maintaining this standard helps mitigate the risk of waterborne diseases. When fecal coliform levels exceed this threshold, it prompts further investigation and possible remediation efforts to address the source of contamination, thereby maintaining water quality and safety for human use.

In terms of the incorrect options, lower colony counts would not reflect the necessary concern for public health, while higher counts would breach the standard set by the EPA, indicating unacceptable levels of contamination. Therefore, understanding the implications of the 2 colonies per 1 ml standard is critical for environmental monitoring and public safety.