Wastewater Chapter 5 NEHA

The wastewater from the flushing of a water closet, latrine, or privy is referred to as:

• gray water

• black water

• green water

• brown water

If a septic tank is pumped during a wet period, the

• water may flow into the tank

• field may flood the tank

• tank may float out of the ground

• tank may be crushed by the wet earth

Nutrients associated with eutrophication include all of the following EXCEPT

• organic carbon

• potassium

• nitrogen

• phosphates

Which of the following is LEAST important when reducing sewage to gases?

• anaerobic bacteria

• earthworms

• protozoa

• aerobic bacteria

A septic tank maintenance worker has checked an empty tank for the presence of hydrogen sulfide (H2S). The test was negative, and there are no odors indicating the presence of other hazardous gases. Is the tank safe to enter without a respirator and supplied air?

• Yes, because hydrogen sulfide and odors were not detected

• No, because oxygen content and methane were not tested

• Yes, because the absence of odors and H2S indicates acceptable confined space entry conditions

• No, because a lack of H2S is a sign of a hazardous confined space atmosphere

All of the following are true about ozone (03) as a disinfectant EXCEPT which one?

• Non Toxic to aquatic organisms

• Source of dissolved oxygen

• Excellent viricide

• Long lasting residual

Aerobic bacteria require all of the following EXCEPT

• carbon

• magnesium

• phosphorus

• nitrogen

What does a mottled brown and red soil indicate?

• Unsuitability for absorption due to chemical composition

• Suitability for absorption due to granular structure

• Inadequate aeration methods

• Adequate agglomeration

Lime coagulation, mixed media filtration, and activated carbon filtration will greatly reduce

• heavy metals

• biological contaminants

• EPA priority pollutants

• EPA listed hazardous wates

It is known that some common pathogenic organisms found in wastewater will survive more than ______ of harsh temperature extremes

• 2 months

• 5 months

• 2 years

• 5 years