Study Guide Answer Key

Here are the answers to the June 4, 2020 edition of TPO's Exam Study Guide: 1. What is the most common type of lagoons currently in use to treat municipal wastewater? The answer to this question is D. Currently the most common lagoon treatment system in use is the facultative lagoon. These lagoons are typically 3 to 8 feet deep. They have dual layers, the upper layer is an aerobic layer and the bottom is an anaerobic layer. The algae found in the aerobic layer supply the dissolved oxygen. Light penetration determines the aerobic layers depth. The waste byproducts from the aerobic layer trickle