What does "total coliform" testing indicate in treated wastewater?

Total coliform testing is a key indicator of the microbiological quality of treated wastewater. The presence of total coliform bacteria suggests that there could be contamination from fecal sources or other environmental contaminants, which may include harmful pathogens. Coliforms are found in the intestines of warm-blooded animals, so their detection in treated wastewater can signal a failure in the treatment process, indicating that the water might not be safe for reuse or discharge into the environment.

By measuring the levels of total coliforms, operators can assess the overall hygiene and safety of the treated water, which is crucial for maintaining public health and environmental standards. This testing is part of routine monitoring because high levels of coliform bacteria can also indicate the potential presence of other harmful microorganisms.

The other options refer to different aspects of wastewater quality; however, they do not directly relate to what total coliform testing specifically indicates. The presence of pathogens pertains to a broader category of harmful organisms, the quality of sludge is assessed through different parameters, and the level of oxygen saturation measures the ability of water to support aquatic life, none of which are the specific focus of total coliform testing.