1

Understanding Wastewater & Sewers

Erie County Department ofEnvironment &

Planning

Division of Sewerage

Management

2

Water

Is our MostIs our MostVALUABLEVALUABLERESOURCERESOURCE

MostMostValuableValuable

3

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

4

Why Conserve Water ?

We have a limitedamount of water anda growing population!

5

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

6

How Much Water Do WeUse and Where ?

7

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

8

Goes down the drainGoes down the drain

What Happens to Water That’sNot Consumed ?

DirtyDirty

SmellySmelly

HiddenHidden}} OOS/OOM

&and becomesand becomeswastewaterwastewater

9

“OOS/OOM”

Out OfMind

Out OfSight

10

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

11

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%)

12

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

13

Where Does It Go from There?

W H E R E

14

Where Does It Go from There?

S E W E R S

15

What is a SEWER?

Series of pipes

Below ground

Conveys wastewater

Sewer has access points

• House connections

• Manholes

16

What We Should NOTPut Into Sewers ?

Paints

Solvents

Pesticides

Storm water

Oil

Gasoline

Plastics

Grease

PaintPaint

ThinnerThinner

17

Why Not?

Damage Sewers Corrosive

Explosive

FireBlock Sewers

Difficult to remove

Create odors

Overload Treatment Plant Reduce Capacity

18

DAMAGED SEWERS

19

For Example:Blocked Sewer

20

Where Should We Put Them?

Special Disposal Places(check with Erie County or local Town officials)

21

HOUSEHOLD WASTE DISPOSAL

Erie County Household Hazardous Waste Drop-Off

Day

Contact: (716)858-6800Or

www.erie.gov/environment

22

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?

23

24

How Do We Get WastewaterUp a Hill ?

SewerSewer PumpPump

PumpedPumpedWastewaterWastewater

(Uphill)(Uphill)

GravityGravityWastewater FlowWastewater Flow

(Downhill)(Downhill)HillHill

SewerSewer

It needs to be PUMPED !

25

What is Sewer Pipe Made Of ?

ClayClayNot Used - Old PipeNot Used - Old Pipe

MetalMetalSpecial CasesSpecial Cases

ConcreteConcreteLarger LinesLarger Lines

PlasticPlasticNew- Most CommonNew- Most Common

26

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”

+

27

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

28

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.

29

Manholes - Why Do We Need Them ?

Provide access to sewers toLook atFixCleanMonitor/sample

Join pipesChange direction/

pipe size/slopeProvide venting

30

Sewer View From Above

31

Sewer View From Above

ManholeManhole

Manhole

JoiningPipe

IncreasingPipe Size

Changing PipeDirection

IncreasingPipe Size8”

8” 12”

12”

14”

32

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

33

But Why Send to a Treatment

Plant

Why Not Discharge to

a River Or Lake

34

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

35

Why Not Discharge to aRiver or Lake?

Major concern –

BACTERIA/HEALTH

&

LOW OXYGEN LEVEL

36

Why Not Discharge to aRiver or Lake?

Bacteria/pathogens are harmful• Humans

• Fish

Low Oxygen Level • Fish cannot survive

37

Wastewater Treatment Plants

Sewers discharge to wastewater treatment plants (WWTPs)

WWTPs remove• Bacteria/Pathogens

• Organic matter

• Solids

WWTPs discharge• Cleaner water

BUT HOW?

38

Wastewater Treatment Plant Summary

Bar ScreenBar Screen Grit TankGrit Tank Solids SettlingSolids Settling

1 2 3Steps

5 4

Biological TreatmentBiological TreatmentDisinfectionDisinfection

Chlorineor

UltravioletCleanCleanWaterWater

39

Step 1: Bar Screens

40

Bar Screens

41

Step 2 - Grit Removal

Grit can be:• Egg shells

• Coffee grinds

• Nut shells

• Seeds

• Sand

• Pebbles

• Pits

42

Grit Tank

43

Step 3 - Solids Settling

Settling Tank

WW EffluentWW Effluent

WWWW

Solids Building Up

Settling TankSolids

Settling

SolidsSettling

Remove SolidsWas

tew

ater

Fee

d

44

Step 3 - Solids Settling

Solids can be:FoodPoop

Settling Tank Removes Solids from Wastewater

45

Solids Settling - Circular Clarifier

46

Solids Settling - Circular Clarifier

47

Step 4 - Biological Treatment

Aeration tank removes soluble organic material from wastewater• Hungry bugs eat

organic material (food)

• Clean wateris left

48

AerationTank

49

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

50

Disinfection (chlorine contact)

51

Disinfection (Ultraviolet)

52

Wastewater Treatment Plant Summary

Bar ScreenBar Screen Grit TankGrit Tank Solids SettlingSolids Settling

1 2 3Steps

5 4

Biological TreatmentBiological TreatmentDisinfectionDisinfection

Chlorineor

UltravioletCleanCleanWaterWater

53

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

54

Dewatering

Dewatering

Why?- To reduce amount of water in solids- To reduce disposal volume- More water in solids = more cost $$$

55

Plant Solids

To Landfill

AnaerobicDigester

SolidsDewatering

PrimaryClarifierSolids

FinalClarifierSolids

56

THE FINAL RESULT –

CLEAN WATER & HEALTHY ENVIRONMENT

57

ECDSM