California Wastewater Treatment Operator Practice Exam

What does a plant influent temperature typically range in comparison to tap water?

1. Colder than tap water

2. Equal to tap water

3. Slightly warmer than tap water

4. Significantly warmer than tap water

The correct answer is: Slightly warmer than tap water

A plant influent temperature typically ranges slightly warmer than tap water due to several factors related to the wastewater treatment process. When wastewater enters a treatment facility, it may have a higher temperature primarily because it often includes contributions from industrial discharges, heated water from residential use, and the natural warming from bacterial activity during the decomposition of organic matter. While tap water is generally around 50°F to 60°F (10°C to 15°C) depending on the region and season, the influent can be influenced by these warmer sources, resulting in temperatures above this range but not excessively high. Thus, characterizing the influent temperature as slightly warmer than tap water reflects the typical conditions found in wastewater treatment facilities.