SEWAGE TREATMENT EVALUATION EXAM 2025
QUESTIONS WITH ANSWERS RATED A+
✔✔>85% SS&BOD; recycle sludge; <30mg/L - ✔✔More than 85% of suspended solids
and biochemical oxygen demand removed in secondary treatment, sludge recycled, and
effluent with less than 30mg/L
✔✔Old outfall: Sand Island (1976) - ✔✔Previous location of sewage discharge in Sand
Island
✔✔Pre-diversion - ✔✔Condition before diversion of sewage
✔✔Post-diversion - ✔✔Condition after diversion of sewage
✔✔Primary and secondary water treatment - ✔✔Focuses on removal of biochemical
oxygen demand, suspended solids, and pathogens
✔✔Nutrients - ✔✔Elements such as nitrogen and phosphorus in sewage that can
stimulate growth
✔✔Aerobic respiration - ✔✔Process of breaking down organic matter using oxygen
✔✔New production - ✔✔Growth of new biomass from discharged sewage nutrients
✔✔BOD of new biomass - ✔✔Biochemical oxygen demand of the new biomass
✔✔Total N of raw sewage - ✔✔Total nitrogen content of raw sewage
✔✔Discharged N - ✔✔Nitrogen discharged in sewage
✔✔BODraw sewage - ✔✔Biochemical oxygen demand of raw sewage
✔✔Nutrient removal efficiency - ✔✔Percentage of nutrients removed in tertiary
treatment
✔✔Cost to taxpayer of POTW - ✔✔Total cost to taxpayers of publicly owned treatment
works
✔✔Land applications of 2o treated sewage - ✔✔Using secondary treated sewage for
crop irrigation
✔✔Spray irrigation studies - ✔✔Studies on the safe and practical use of spray irrigation
with sewage effluent
, ✔✔Crop yields - ✔✔Yields of different crops with and without sewage effluent
✔✔Residual pathogens - ✔✔Pathogens that remain in treated sewage effluent
✔✔Nitrate buildup - ✔✔Accumulation of nitrate in soils from land applications of sewage
✔✔Salt buildup in soils - ✔✔Accumulation of salt in soils from land applications of
sewage
✔✔Heavy metals in soils - ✔✔Presence of heavy metals in soils from industrial wastes
✔✔Salt contamination - ✔✔Contamination of soil with salt due to irrigation
✔✔Groundwater quality - ✔✔Quality of underground water sources
✔✔Fecal pathogen contamination - ✔✔Presence of pathogens in wastewater aerosols
✔✔Nutrient concentrations - ✔✔Concentrations of nutrients in wastewater
✔✔Variables controlling spray irrigation effects - ✔✔Factors that influence the effects of
spray irrigation
✔✔Wastewater spray rate - ✔✔Rate at which wastewater is sprayed
✔✔Wastewater composition - ✔✔Chemical composition of wastewater
✔✔Plant types - ✔✔Types of plants used in spray irrigation
✔✔Soil type - ✔✔Type of soil used in spray irrigation
✔✔Rainfall - ✔✔Amount of rain received in an area
✔✔Packaged waste water treatment systems - ✔✔Pre-engineered structures for
wastewater treatment
✔✔Membrane bioreactor - ✔✔Wastewater treatment system that uses membranes and
biological processes
✔✔Constructed wetlands - ✔✔Wetlands designed to treat wastewater
✔✔R-1: Tertiary treated recycled water - ✔✔Recycled water that can be used without
restrictions
QUESTIONS WITH ANSWERS RATED A+
✔✔>85% SS&BOD; recycle sludge; <30mg/L - ✔✔More than 85% of suspended solids
and biochemical oxygen demand removed in secondary treatment, sludge recycled, and
effluent with less than 30mg/L
✔✔Old outfall: Sand Island (1976) - ✔✔Previous location of sewage discharge in Sand
Island
✔✔Pre-diversion - ✔✔Condition before diversion of sewage
✔✔Post-diversion - ✔✔Condition after diversion of sewage
✔✔Primary and secondary water treatment - ✔✔Focuses on removal of biochemical
oxygen demand, suspended solids, and pathogens
✔✔Nutrients - ✔✔Elements such as nitrogen and phosphorus in sewage that can
stimulate growth
✔✔Aerobic respiration - ✔✔Process of breaking down organic matter using oxygen
✔✔New production - ✔✔Growth of new biomass from discharged sewage nutrients
✔✔BOD of new biomass - ✔✔Biochemical oxygen demand of the new biomass
✔✔Total N of raw sewage - ✔✔Total nitrogen content of raw sewage
✔✔Discharged N - ✔✔Nitrogen discharged in sewage
✔✔BODraw sewage - ✔✔Biochemical oxygen demand of raw sewage
✔✔Nutrient removal efficiency - ✔✔Percentage of nutrients removed in tertiary
treatment
✔✔Cost to taxpayer of POTW - ✔✔Total cost to taxpayers of publicly owned treatment
works
✔✔Land applications of 2o treated sewage - ✔✔Using secondary treated sewage for
crop irrigation
✔✔Spray irrigation studies - ✔✔Studies on the safe and practical use of spray irrigation
with sewage effluent
, ✔✔Crop yields - ✔✔Yields of different crops with and without sewage effluent
✔✔Residual pathogens - ✔✔Pathogens that remain in treated sewage effluent
✔✔Nitrate buildup - ✔✔Accumulation of nitrate in soils from land applications of sewage
✔✔Salt buildup in soils - ✔✔Accumulation of salt in soils from land applications of
sewage
✔✔Heavy metals in soils - ✔✔Presence of heavy metals in soils from industrial wastes
✔✔Salt contamination - ✔✔Contamination of soil with salt due to irrigation
✔✔Groundwater quality - ✔✔Quality of underground water sources
✔✔Fecal pathogen contamination - ✔✔Presence of pathogens in wastewater aerosols
✔✔Nutrient concentrations - ✔✔Concentrations of nutrients in wastewater
✔✔Variables controlling spray irrigation effects - ✔✔Factors that influence the effects of
spray irrigation
✔✔Wastewater spray rate - ✔✔Rate at which wastewater is sprayed
✔✔Wastewater composition - ✔✔Chemical composition of wastewater
✔✔Plant types - ✔✔Types of plants used in spray irrigation
✔✔Soil type - ✔✔Type of soil used in spray irrigation
✔✔Rainfall - ✔✔Amount of rain received in an area
✔✔Packaged waste water treatment systems - ✔✔Pre-engineered structures for
wastewater treatment
✔✔Membrane bioreactor - ✔✔Wastewater treatment system that uses membranes and
biological processes
✔✔Constructed wetlands - ✔✔Wetlands designed to treat wastewater
✔✔R-1: Tertiary treated recycled water - ✔✔Recycled water that can be used without
restrictions
