On-Site Sewage Treatment Basics & System
:
Design — Comprehensive Study Guide | Updated
2025 Edition
Who was our lecturer? - ANSW✔️Sara Heger
What are the 3 approaches to wastewater treatment? - ANSW✔️1) Centralized
-collection network for many homes with central treatment facility
-surface discharge (PCA permit)
2) Decentralized
-individual/small groups of homes with onsite treatment
-soil based dispersal/subsurface discharge (PCA permit)
3) Combination of the two
What four components make up an onsite wastewater treatment system? - ANSW✔️1) Wastewater
source
2) Collection and storage
3) Pretreatment compounds
4) Final treatment and dispersal components (->groundwater->well->source)
What methods are used in primary treatment of wastewater (minimum)? - ANSW✔️-stabilization
ponds
-septic tank
What methods are used in secondary treatment of wastewater? - ANSW✔️-activated sludge
-trickling filter
,-standard soil treatment area
What methods are used in disinfection of wastewater? - ANSW✔️-chlorination
-dechlorination
-UV
-ozone
What methods are used in advance wastewater treatment? - ANSW✔️-N removal
-P removal
-filtration
Where does Minneapolis's drinking water come from? - ANSW✔️Mississippi River
How many times has the water in the Mississippi River been digested once it reaches New Orleans? -
ANSW✔️8 times
What is the current goal for wastewater treatment? - ANSW✔️Dispersal
What was the past goal for wastewater treatment? - ANSW✔️Disposal
What is the limiting factor for tech advancements allowing removal of pathogens, solids, nutrients? -
ANSW✔️Cost
List advantages of decentralized systems in wastewater treatment. - ANSW✔️-cost effective
-easier maintenance
-lower O&M requirements
-lower energy requirements
-flexible design
-enhancement for reuse
, -green development
-sewer extent limited
-multiple, small discharges = enhanced assimilation
-conserves water w/in wtsd: groundwater recharge
-avoid large mass loading at outfalls
-malfunction risks smaller and more manageable
-
How many septic tanks are in MN? - ANSW✔️600,000
How many people use decentralized systems for wastewater treatment in the US? - ANSW✔️25%
How many of the decentralized systems in the US are in suburbs or cities? - ANSW✔️>50%
How many gallons of water do typical toilets use for flushing? - ANSW✔️5 gallons
How many gallons of water do newer toilets use for flushing? - ANSW✔️1.6 gallons
Why are septic systems used? - ANSW✔️-to treat/disperse of wastewater where sewers aren't
available, desirable, or affordable (biggest issue!)
Which states have >40% residents using septic systems? - ANSW✔️Maine
Vermont
New Hampshire
West Virginia
Kentucky
Mississippi
Alabama
North Carolina
:
Design — Comprehensive Study Guide | Updated
2025 Edition
Who was our lecturer? - ANSW✔️Sara Heger
What are the 3 approaches to wastewater treatment? - ANSW✔️1) Centralized
-collection network for many homes with central treatment facility
-surface discharge (PCA permit)
2) Decentralized
-individual/small groups of homes with onsite treatment
-soil based dispersal/subsurface discharge (PCA permit)
3) Combination of the two
What four components make up an onsite wastewater treatment system? - ANSW✔️1) Wastewater
source
2) Collection and storage
3) Pretreatment compounds
4) Final treatment and dispersal components (->groundwater->well->source)
What methods are used in primary treatment of wastewater (minimum)? - ANSW✔️-stabilization
ponds
-septic tank
What methods are used in secondary treatment of wastewater? - ANSW✔️-activated sludge
-trickling filter
,-standard soil treatment area
What methods are used in disinfection of wastewater? - ANSW✔️-chlorination
-dechlorination
-UV
-ozone
What methods are used in advance wastewater treatment? - ANSW✔️-N removal
-P removal
-filtration
Where does Minneapolis's drinking water come from? - ANSW✔️Mississippi River
How many times has the water in the Mississippi River been digested once it reaches New Orleans? -
ANSW✔️8 times
What is the current goal for wastewater treatment? - ANSW✔️Dispersal
What was the past goal for wastewater treatment? - ANSW✔️Disposal
What is the limiting factor for tech advancements allowing removal of pathogens, solids, nutrients? -
ANSW✔️Cost
List advantages of decentralized systems in wastewater treatment. - ANSW✔️-cost effective
-easier maintenance
-lower O&M requirements
-lower energy requirements
-flexible design
-enhancement for reuse
, -green development
-sewer extent limited
-multiple, small discharges = enhanced assimilation
-conserves water w/in wtsd: groundwater recharge
-avoid large mass loading at outfalls
-malfunction risks smaller and more manageable
-
How many septic tanks are in MN? - ANSW✔️600,000
How many people use decentralized systems for wastewater treatment in the US? - ANSW✔️25%
How many of the decentralized systems in the US are in suburbs or cities? - ANSW✔️>50%
How many gallons of water do typical toilets use for flushing? - ANSW✔️5 gallons
How many gallons of water do newer toilets use for flushing? - ANSW✔️1.6 gallons
Why are septic systems used? - ANSW✔️-to treat/disperse of wastewater where sewers aren't
available, desirable, or affordable (biggest issue!)
Which states have >40% residents using septic systems? - ANSW✔️Maine
Vermont
New Hampshire
West Virginia
Kentucky
Mississippi
Alabama
North Carolina
