When considering the surface overflow rates of primary settling tanks in a typical municipal wastewater treatment plant, which of the following statements is not correct?
A)Sizing should reflect the degree of solids removal necessary
B)Sizing is based on measured flow conditions
C)Septic conditions should be avoided during low flow periods
D)None of the above

Question

Quizplus · Accepted Answer

The statement, "Sizing is based on the measured flow conditions" is not correct when considering the surface overflow rates of primary settling tanks. Typically, the primary settling tanks are sized based on the surface area calculations performed using 1) the design average flow conditions and 2) design peak hourly flow conditions. The larger surface area of the two is used to size the primary setting tank. Specific design requirements for primary settling tanks are set by state regulating agencies.

When Considering the Surface Overflow Rates of Primary Settling Tanks