Exam Study Guide


During nitrification in an aeration tank, which of the following parameters will decrease?

A. Alkalinity

B. Oxidation reduction potential, or ORP

C. Nitrate

D. Nitrite

Answer: A. As nitrification progresses through the aeration tank, nitrifying bacteria consume some of the alkalinity present in the mixed liquor for their metabolic processes. They obtain their carbon source from carbon dioxide and bicarbonate alkalinity, while at the same time, some of these bacteria produce acids. This depletion of carbonate alkalinity and acid production reduces the available alkalinity. Once the alkalinity drops to critical levels, nitrification can slow or stop, leaving ammonium or nitrite present in the mixed liquor. The other parameters listed (ORP, nitrate and nitrite) will usually increase as nitrification takes place. Nitrite is produced but should oxidize further to nitrate, provided all the necessary conditions exist. About 7.14 parts of alkalinity are consumed for each part of ammonium oxidized to nitrate.


How should consumer complaints and questions be handled in the field by water distribution system operators?

A. Crew members should answer routine questions, but direct others to the homeowners association.

B. Crew members should direct all consumer questions to the supervisor, no matter how difficult.

C. Shut off the consumers’ service until all complaints and questions are resolved.

D. Crew members should answer routine questions, but direct all other questions to their supervisor.

Answer: D. It is generally accepted practice that water distribution system personnel be able to answer routine questions from their water service customers about things like water quality, general treatment questions and billing methods. Please do not confuse this statement with the accepted practice set in place by your utility; you may have a different standard operating procedure, or SOP, when dealing with the public, and you should always follow your SOP. However, the American Water Works Association Water Distribution System Operator Training Handbook recommends the response of answer D. Always remember that the face of the utility may be the members of the distribution system field crew, as they interacts with the public much more frequently than plant operators and managers. Field crew members and supervisors should be trained to handle routine questions and situations while referring very technical questions or hostile situations to utility managers.

About the author

Ron Trygar, a certified environmental trainer, is the senior training specialist for water and wastewater programs at the University of Florida TREEO Center. He has worked in the wastewater industry for more than 30 years and holds Class A wastewater treatment operator and Class B drinking water operator licenses in Florida.


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