What microorganisms are commonly found in wastewater?

The presence of various microorganisms in wastewater is essential to understand, especially in the context of on-site sewage facilities. The correct choice identifies a comprehensive range of microorganisms that are commonly found in wastewater, which includes bacteria, viruses, protozoa, and helminths.

Bacteria are the most abundant microorganisms in wastewater and play a crucial role in the decomposition of organic matter. They are instrumental in biological treatment processes, as they help break down pollutants. Viruses can also be present in wastewater, particularly those associated with human or animal waste, and they can sometimes pose health risks.

Protozoa are larger, single-celled organisms that feed on bacteria and other small particles in the wastewater. They are important for indicating the treatment efficiency of biological systems. Helminths, which are parasitic worms, can also be found in wastewater, particularly in systems that handle human or animal waste, and they can lead to health concerns if the treated effluent is not properly managed.

In comparison, the other choices either limit the variety of microorganisms listed or exclude significant groups. While options mentioning only bacteria and viruses or limiting the focus to fungi and bacteria capture some of the relevant microorganisms, they fail to encompass the full spectrum found in wastewater, which is critical for understanding the