ETC Water Quality & Treatment

Question 1

Which federal law establishes Maximum Contaminant Levels (MCLs) for drinking water contaminants and is enforced by the EPA?

Accepted Answer

Safe Drinking Water Act (SDWA)

Answer

Clean Water Act (CWA)

Answer

Resource Conservation and Recovery Act (RCRA)

Answer

Toxic Substances Control Act (TSCA)

Question 2

In wastewater treatment, what is Biochemical Oxygen Demand (BOD) a measure of?

Accepted Answer

The amount of oxygen consumed by microorganisms when decomposing organic matter in water

Answer

The concentration of dissolved oxygen in treated effluent

Answer

The chemical oxygen required to oxidize all organic and inorganic matter in a sample

Answer

The oxygen demand created by nitrogen compounds during nitrification

Question 3

What is the primary treatment objective of coagulation and flocculation in a drinking water treatment plant?

Accepted Answer

To aggregate suspended particles and colloids into larger settleable masses

Answer

To disinfect water by killing pathogenic bacteria

Answer

To remove dissolved organic compounds through adsorption

Answer

To adjust pH before chlorination

Question 4

Which water quality parameter, measured in mg/L as CaCO3, indicates the water's ability to resist changes in pH?

Accepted Answer

Alkalinity

Answer

Hardness

Answer

Total Dissolved Solids (TDS)

Answer

Chloride concentration

Question 5

What is the purpose of the National Pollutant Discharge Elimination System (NPDES) permit program under the Clean Water Act?

Accepted Answer

To control point source discharges of pollutants into navigable waters of the United States

Answer

To regulate underground injection of waste fluids

Answer

To establish cleanup standards for contaminated surface water bodies

Answer

To regulate nonpoint source agricultural runoff

Question 6

In a biological wastewater treatment system using activated sludge, what is the function of the aeration basin?

Accepted Answer

To provide oxygen and contact time for microorganisms to metabolize dissolved organic matter

Answer

To settle and remove biological solids from the treated effluent

Answer

To chemically precipitate phosphorus from the wastewater

Answer

To filter out suspended solids using media filtration