Here are the answers to the Dec. 8, 2022 edition of TPO's Exam Study Guide:

When referring to odors and odor control in wastewater treatment, what is the definition of odor threshold?

The answer to the question is C. Odor control has become an important topic in many wastewater treatment facilities due to surrounding community growth. The point where the lowest concentration at which a compound can be detected by human smell is known as the odor threshold. It is the point where you can detect the odor. Odors in wastewater treatment may be from anaerobic decay (fermentation) or the production of sulfides. Understanding odor control measures and production of odors in the treatment process is essential for proper operation of wastewater treatment facilities and being a good neighbor.

For bacteria contamination, repeat samples are required to be collected:

The correct answer is A, within 24 hours of being notified. Bacteriological samples are collected from potable water distribution systems every month. These samples help ensure the water is safe to consume. Occasionally, a system will have a sample test positive for total coliform and will be required to collect repeat samples. The repeat sample are required to be collected within 24 hours of being notified by the certified laboratory.