A wastewater treatment plant touts its chlorine-based disinfection process as "the safest, simplest, most flexible process in the treatment business." Which part of the plant's claim, if any, is likely accurate? Which part of the plant's claim, if any, is likely inaccurate?
This diagram shows the treatment process used at a certain water treatment plant. Shortly after the plant is constructed, the operators discover that water treated at the plant still contains spores and other pathogens. Explain which step is missing from the treatment process, and explain how adding this step would solve the problem.