WASTEWATER

By Rick Lallish

What is the activated sludge collected in the secondary clarifier then sent to the aeration basin referred to as?

A. WAS

B. BOD

C. Effluent

D. RAS

Answer: D. Return activated sludge. Many modern activated sludge plants run automatically with most of the equipment programmed to operate at certain levels. Sometimes operators have to make decisions to help the plant run better. One is determining the return activated sludge flow. This can be based on current conditions, blanket levels in the clarifier, or shock load remediation. By determining RAS levels, the operator decides where the sludge or bugs are needed more (clarifier or aeration basin). More information may be found in the OWP, CSU-Sacramento textbook: Operation of Wastewater Treatment Plants, Volume 1, Eighth edition, Chapter 5. 

DRINKING WATER

By Drew Hoelscher

What requires community water systems to assess the risks and resilience of specified assets for their utility operations?

A. America’s Water Infrastructure Act

B. Consumer Confidence Report Rule

C. Surface Water Treatment Rule

D. Public Notification Rule

Answer: A. In 2018, America’s Water Infrastructure Act was signed into law. This act amended section 1433 of the Safe Drinking Water Act. The initial deadlines for updated risk and resilience and emergency response plans were in 2020 and 2021, depending on population served. The next submission cycle is approaching in 2025-26. The emergency response plan certification must be submitted within six months after the risk and resilience assessment certification. The AWIA helps utilities identify risks from malevolent acts and natural hazards, so efficient emergency response plans can be developed.

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.