Exam Study Guide - August 2023


By Rick Lallish

According to U.S. EPA Part 503 regulations, which type of biosolids may be used as soil amendment and/or fertilizer for growing various crops (with some restrictions)?

A. Class A

B. Class B

C. Both/either

D. Neither

Answer: C. Class A biosolids use one of many processes to further reduce pathogen levels below detection limits (1,000 bacteria/gram). Class B biosolids may have relatively high numbers of fecal coliform bacteria (2,000,000 bacteria/gram). Class B may be applied to private land without public access, and Class A may be applied commercially or sold. Both must meet vector attraction reduction requirements. With proper analysis and controls, either classification may be used as a soil amendment for growing certain crops. Please note that many states have differing laws in lieu of or in addition to the Part 503 regulations. More information may be found in the WEF textbook: Wastewater Treatment Fundamentals II: Solids Handling and Support Systems, Chapter 1.


By Drew Hoelscher

What gallon per minute flow can an operator expect if the bonnet on a fire hydrant is painted blue?

A. 1,500+

B. 1,000 to 1,499

C. 500 to 999

D. Less than 500

Answer: A. Fire hydrants serve two main purposes, fire protection and water system maintenance. Typically, hydrants are inspected annually and flow tests are performed every five years. Inspections ensure the unit is in good working order, and flow tests help uncover infrastructure problems in the distribution system. Flow tests also help with designing fire sprinkler systems for commercial buildings. Painting the bonnet of a hydrant identifies the approximate flow in gallons per minute. Blue, 1,500+; Green, 1,000 to 1,499; Orange, 500 to 999; Red, <500

About the author(s)

Rick Lallish is water pollution control program director and Drew Hoelscher is program director of drinking water operations at the Environmental Resources Training Center of Southern Illinois University Edwardsville.  


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