1 understanding wastewater & sewers erie county department of environment & planning...
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Understanding Wastewater & Sewers
Erie County Department ofEnvironment &
Planning
Division of Sewerage
Management
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Water
Is our MostIs our MostVALUABLEVALUABLERESOURCERESOURCE
MostMostValuableValuable
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Why is Water IMPORTANT ?
Water is necessary to all living things
People can live for weeks without food, but only a few days without water
Water is a delivery system• Nutrients in soil• Blood in humans/animals• Carries off bodily wastes
Our body is water cooled
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Why Conserve Water ?
We have a limitedamount of water anda growing population!
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Who Uses Water ?
People Industry Farmers Utilities
(making electricity)
Water used in 1 day in USA - 450 billion Water used in 1 day in USA - 450 billion gallonsgallons450,000,000,000 gallons ( >7 trillion cups 450,000,000,000 gallons ( >7 trillion cups ))
WaterWaterSupplySupply
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How Much Water Do WeUse and Where ?
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Daily Water Usage
Family & Industrial
US
Japan
Ghana (W. Africa)
All of Europe
450,000,000,000 gallons
150,000,000,000 gallons
6, 400,000,000 gallons
170,000,000,000 gallons
Water Trivia: US needs 115,000,000,000 gals/day of drinking waterWater Trivia: US needs 115,000,000,000 gals/day of drinking water
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Goes down the drainGoes down the drain
What Happens to Water That’sNot Consumed ?
DirtyDirty
SmellySmelly
HiddenHidden}} OOS/OOM
&and becomesand becomeswastewaterwastewater
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“OOS/OOM”
Out OfMind
Out OfSight
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One Person, One Day:
Flush ToiletFlush Toilet
Shower/BathShower/Bath
Brush TeethBrush Teeth
Wash HandsWash Hands
15 gal15 gal
35 gal35 gal
4 gal4 gal
6 gal6 gal
(5 gal x 3 )(5 gal x 3 )
(2 gal x 2 )(2 gal x 2 )
(2 gal x 3 )(2 gal x 3 )
60 gallons/person*60 gallons/person*
JUNE15, 2006
* Range: 50-100 gallons/person-day
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Typical Family Wastewater
Total usage 14.5 billion gallons per dayTotal usage 14.5 billion gallons per day
Dishwasher(2%) Kitchen
Sink (8%)
Bathroom Sink (11%)
Bathing (20%)WashingWashing
Clothes Clothes (26%)(26%)
Toilet Toilet (33%)(33%)
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What Happens to the Wastewater From Each Source?
Where does the drain pipe lead? Connects with other drains Series of house pipes
Usually in the basement
Goes down a DRAIN
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Where Does It Go from There?
W H E R E
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Where Does It Go from There?
S E W E R S
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What is a SEWER?
Series of pipes
Below ground
Conveys wastewater
Sewer has access points
• House connections
• Manholes
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What We Should NOTPut Into Sewers ?
Paints
Solvents
Pesticides
Storm water
Oil
Gasoline
Plastics
Grease
PaintPaint
ThinnerThinner
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Why Not?
Damage Sewers Corrosive
Explosive
FireBlock Sewers
Difficult to remove
Create odors
Overload Treatment Plant Reduce Capacity
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DAMAGED SEWERS
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For Example:Blocked Sewer
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Where Should We Put Them?
Special Disposal Places(check with Erie County or local Town officials)
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HOUSEHOLD WASTE DISPOSAL
Erie County Household Hazardous Waste Drop-Off
Day
Contact: (716)858-6800Or
www.erie.gov/environment
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Wastewater Flow in Sewers
Why is the sewer pipe tilted downward?– Water flows by gravity– From high point to low point
Have you ever seen water run uphill?
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How Do We Get WastewaterUp a Hill ?
SewerSewer PumpPump
PumpedPumpedWastewaterWastewater
(Uphill)(Uphill)
GravityGravityWastewater FlowWastewater Flow
(Downhill)(Downhill)HillHill
SewerSewer
It needs to be PUMPED !
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What is Sewer Pipe Made Of ?
ClayClayNot Used - Old PipeNot Used - Old Pipe
MetalMetalSpecial CasesSpecial Cases
ConcreteConcreteLarger LinesLarger Lines
PlasticPlasticNew- Most CommonNew- Most Common
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Sewer Pipe Size
Does one size sewer pipe fit all places
NO
Pipe size is increased as more wastewater is introduced from additional homes
6” 8” 10” 12” 16” 20” 24” 30” 36”
+
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Can You See Sewer Pipes ?
No!How Do You Know They Are There ?How Do You Know They Are There ?
ManholeManholeCoversCovers
• Streets• Sidewalks• Private Property
Where
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Can You See Sewer Pipes ?
Look for the connection from your house to the sewer. Look for your Cleanout,
it’s usually in you lawn.
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Manholes - Why Do We Need Them ?
Provide access to sewers toLook atFixCleanMonitor/sample
Join pipesChange direction/
pipe size/slopeProvide venting
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Sewer View From Above
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Sewer View From Above
ManholeManhole
Manhole
JoiningPipe
IncreasingPipe Size
Changing PipeDirection
IncreasingPipe Size8”
8” 12”
12”
14”
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What Happens at a Wastewater Treatment Plant ?
Dirty waterDirty water(called wastewater or sewage)(called wastewater or sewage)
is cleaned….is cleaned….HOWHOW??
Through treatment processThrough treatment processby
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But Why Send to a Treatment
Plant
Why Not Discharge to
a River Or Lake
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Why Not Discharge to aRiver or Lake?
River/Lake• Untreated wastewater will make humans sick
• Untreated wastewater will kill fish and other aquatic life.
• Impacts water quality
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Why Not Discharge to aRiver or Lake?
Major concern –
BACTERIA/HEALTH
&
LOW OXYGEN LEVEL
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Why Not Discharge to aRiver or Lake?
Bacteria/pathogens are harmful• Humans
• Fish
Low Oxygen Level • Fish cannot survive
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Wastewater Treatment Plants
Sewers discharge to wastewater treatment plants (WWTPs)
WWTPs remove• Bacteria/Pathogens
• Organic matter
• Solids
WWTPs discharge• Cleaner water
BUT HOW?
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Wastewater Treatment Plant Summary
Bar ScreenBar Screen Grit TankGrit Tank Solids SettlingSolids Settling
1 2 3Steps
5 4
Biological TreatmentBiological TreatmentDisinfectionDisinfection
Chlorineor
UltravioletCleanCleanWaterWater
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Step 1: Bar Screens
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Bar Screens
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Step 2 - Grit Removal
Grit can be:• Egg shells
• Coffee grinds
• Nut shells
• Seeds
• Sand
• Pebbles
• Pits
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Grit Tank
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Step 3 - Solids Settling
Settling Tank
WW EffluentWW Effluent
WWWW
Solids Building Up
Settling TankSolids
Settling
SolidsSettling
Remove SolidsWas
tew
ater
Fee
d
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Step 3 - Solids Settling
Solids can be:FoodPoop
Settling Tank Removes Solids from Wastewater
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Solids Settling - Circular Clarifier
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Solids Settling - Circular Clarifier
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Step 4 - Biological Treatment
Aeration tank removes soluble organic material from wastewater• Hungry bugs eat
organic material (food)
• Clean wateris left
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AerationTank
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Step 5 - Disinfection
CleanEffluent
CleanWater
Chlorine ContactTank
ChlorineChlorine
CleanEffluent
CleanWater
(UV) Ultraviolet Bulbs(UV) Ultraviolet Bulbs
-OR-
Disinfection removes bugs from clean water before discharge Chlorine or
ultraviolet light kills bugs
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Disinfection (chlorine contact)
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Disinfection (Ultraviolet)
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Wastewater Treatment Plant Summary
Bar ScreenBar Screen Grit TankGrit Tank Solids SettlingSolids Settling
1 2 3Steps
5 4
Biological TreatmentBiological TreatmentDisinfectionDisinfection
Chlorineor
UltravioletCleanCleanWaterWater
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But What Do We Do With The Solids Collected?
Bar ScreenBar Screen Grit TankGrit Tank Solids SettlingSolids Settling
1 2 3Steps
5 4
Biological TreatmentBiological TreatmentDisinfectionDisinfection
Chlorineor
UltravioletCleanCleanWaterWater
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Dewatering
Dewatering
Why?- To reduce amount of water in solids- To reduce disposal volume- More water in solids = more cost $$$
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Plant Solids
To Landfill
AnaerobicDigester
SolidsDewatering
PrimaryClarifierSolids
FinalClarifierSolids
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THE FINAL RESULT –
CLEAN WATER & HEALTHY ENVIRONMENT
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ECDSM