INTRODUCTIONWATER SUPPLY

Three kinds of supply:

1) Government Supply

2) Private Supply

- Regulated by Public Utilities Commissions (Government)

3) Self Supplied

WATER CONSUMPTION

- Consumption in USA is the double than in Central Europe.

- Large variation among states.

- Average american family spent $474 on water and sewerage charges

INTRODUCTION

Problems:

1) Water scarcity

2) Pollution

3) Backlog of investment

4) Affordability for the poorest

5) Rapidly retiring workforce

Consequence:

The cities, state government and federal government start paying attention to water conservation and start configuring programs

Source: https://en.wikipedia.org/wiki/Drinking_water_supply_and_sanitation_in_the_United_States

DESCRIPTION OF STRUCTURE AND SPECIFICSThe infrastructure in the USA consists of:

1. Dams and reservoirs

2. Well fields

3. Pumping stations

4. Aqueducts

5. Water treatment plants

6. Water towersSource: https://en.wikipedia.org/wiki/Drinking_water_supply_and_sanitation_in_the_United_States

DESCRIPTION OF STRUCTURE AND SPECIFICSFOUR CASES OF WATER SOURCES

1)Cities supplied by surface water without treatment.

a) Only need disinfection

b) Sources are protected watersheds

c) Examples: Boston and New York

2)Cities supplied by surface water with treatment.

a) Sources are polluted waters

b) Example: Las Vegas ValleySource: https://en.wikipedia.org/wiki/Drinking_water_supply_and_sanitation_in_the_United_States

PHILADELPHIA- Water Supply regulated by Philadelphia Water Department. Employees: 1,836 Average Daily Treated Water

Delivered: 928 MLD

- Seven subwatersheds:Darby-Cobbs,Delaware direct,Pennypack,Poquessing,Schuylkill,Tookany/Tacony-Frankford and Wissahickon

- Philadelphia receives 60% of its water from the Delaware River and 40% from the Schuylkill River

- Philadelphia has three drinking water treatment plants—Samuel S. Baxter on the Delaware River and Queen Lane

and Belmont on the Schuylkill.

Source:https://en.wikipedia.org/wiki/Philadelphia_Water_Department

CURRENT WATER SUPPLY IN PHILADELPHIA

Source- http://www.phila.gov/water/PublishingImages/WaterDiagramPoster.jpg

CHEMICAL REACTIONS

Coagulation- Addition of ferric chloride (FeCl3) and Lime (CaO).

FeCl3 Fe3 +3Cl H2O H + OH

Fe3 +3OH Fe(OH)3Ferric Hydroxide

CaO + H2O Ca(OH)2Calcium hydroxide/slaked lime

Disinfection- Addition of Sodium Hypochlorite (NaOCl)

NaOCl + H2O

Source-http://www.artmondo.net/printworks/articles/ferric.htmhttp://www.smart-fertilizer.com/articles/chlorine

HOCL +NaOHHypochlorous Sodium Hydroxideacid

DESIGN OF SEDIMENTATION TANKFour Major Zones

Inlet zone : Region in which flow is distributed

Outlet zone: Effluent is discharged

Settling zone : Settling In quiescent conditions

Sludge zone: Collection of sludge

Generalized Design Details

SOURCE:http://nptel.ac.in/courses/105104102/Lecture%206.htm#Design Details

● Detention Period

3-4 hours for plain and 2-2.5 hours for coagulated sedimentation.

● Velocity to flow

Not greater than 30 cm/min(horizontal flow)

● Tank dimensions

L:B=3 to 5:1 Generally L=30 m (common) max 100m.B=6-10m.Diameter=20-40(not greater than 60)

● Depth 2.5 to 5.0 (3m)

● Surface overflow rate

For flocculated 24000-30000 L/d/m2 tank area

● Slope Rectangular 1% towards inlet and Circular 8%

FILTRATIONComponents

Inlet chamber

Sand

Gravel

Sourcehttp://nptel.ac.in/courses/105104102/Lecture%2011.htm

● Maximum length of lateral

Not less than 60 times its diameter.

● Spacing of holes

6mm holes for 7.5cm c/c 13mm for 15 cmc/c

● C.S area of lateral

Not less than 2 times the area of perforations

● C.S area of manifolds

Two times the area of laterals

● Pressure of wash water at perforations

not greater than 1.05 kg/cm2

● Velocity of flow in lateral

2m/s2.25 m/s in manifold

● Amt. of washwater

0.2 to 0.4% of total filtered water

Generalised Design Details

COAGULATION AND FLOCCULATIONFactors affecting coagulation:

Type of coagulant

Quantity or dose of Coagulant

Water characteristics such as :Type and quantity of suspended matter,Temperature of water,pH of water

Time, turbulence and method of mixing

Source:http://nptel.ac.in/courses/1051041 02/Lecture%207.htm

● Depth of tank 3-4.5 m(sometimes 5)

● Detention time

10-40 min

● Velocity of flow

0.2-0.8 m/s

● Total area of paddles

10-25% of c/s area

● Velocity gradient

10to 75 s^-1

● Drag coefficient

1.8 for flat blades

● Power consumption

10-36 KWml/d

● Area of paddles

Length of blades ×width ×number of blades

Generalised Design Details:

MATERIALSParts involved in whole treatment process are

❖ Water Transmission Pipes

❖ Disinfectant Tank ( Chlorination Tank)

❖ Flocculation Tank

❖ Water Filters and Filtration Tank

❖ Final Treatment Setup

MATERIALSCOMPONENT MATERIAL PROPERTY

WATER TRANSMISSION PIPES

DUCTILE IRON WITHSTAND AT HIGH PRESSURE

TANKS FOR FILTRATION FLOCCULATION ETC.

RCC WATERTIGHT AND WITHSTAND HIGH PRESSURE

WATER FILTERS SAND AND CHARCOAL CAN TRAP FINE PARTICLES

FINAL TREATMENT FLUORIDE ZINC ORTHOPHOSPHATE AND

AMMONIA

TO AVOID TOOTH DECAY,MINIMIZE CORROSION OF PIPES AND TO MAINTAIN Cl2

Source: http://www.phila.gov/water/wu/Pages/default.aspx

WATER TRANSMISSION PIPES● Steel Pipes : Durable and strongest piping material. Easy to weld. But

expensive and gets corroded as water is in continuous contact

● Galvanised Steel or Iron Pipes : Traditional piping material but not used widely because of rust if water flow is intermittent also water gets unpalatable odour and taste.

● Concrete Pipes : Watertight. But expensive and not easy to connect two pipes.

DUCTILE IRON● 87% of water transmission pipes in Philadelphia used to be of cast iron

● But by 1960 PWD started using Ductile Iron for water transmission pipes

Properties of ductile iron

● Suitable for above and below ground applications

● Various sizes are available

● Constant performance in hydraulic flow

● Less corrosive than grey cast iron

● Zinc or Aluminium alloy coating to minimize corrosion

DUCTILE IRON Manufacturing of Ductile Iron

● Casting

● During casting process Magnesium or Cerium is added to Grey Cast Iron

● Unlike in Grey Cast Iron instead of forming flakes, graphite forms spherical or nodular structure thereby adding ductility.

Source:http://lh4.ggpht.com/-kK9Gi0601_8/VESy7UK-xjI/AAAAAAAAGPw/z0voX3-GxbE/s1600-h/image%25255B21%25255D.png

CORROSION INHIBITORSSEDIMENTATION,

FLOCCULATION AND FILTRATION TANKS

● Sedimentation, flocculation and filtration tanks are of RCC

● RCC constructions are watertight and can withstand high pressure

● To avoid corrosion of rebars normally concrete layer is thick

● But still salts and water may penetrate concrete and corrode rebars

● To avoid this coating of Corrosion Inhibitors is done on RCC construction

Source https://www.linkedin.com/pulse/protect-rebar-after-concrete-place-john-babun

FLOCCULATION AND FILTRATION● Baffle Plates are made of Fabric Reinforced Plastic (FRP) since this is light

weight material and plastic is corrosion resistant

● Filtering unit contains sand and charcoal

● In final treatment Fluoride is added to water to avoid tooth decay.

● Zinc Orthophosphate to minimize corrosion of pipes

● Ammonia is added to maintain the chlorine content

FUNDING AND ORGANISATIONA State Revolving Fund (SRF) is a fund administered by a U.S. state for the purpose of providing low-interest loans for investments in water and sanitation infrastructure. A SRF receives its initial capital from federal grants and state contributions.

1-) Clean Water State Revolving Fund created in 1987 under the Clean Water Act.The fund is administered by the Environmental Protection Agency and state agencies

2-) Drinking Water State Revolving Fund created in 1997 under the Safe Drinking Water Act.Investment needs are about $14 billion/year for drinking water. State and local governments invested 16.3 billion for drinking water supply in 2008.

Sources: https://web.archive.org/web/20090225015224/http://www.epa.gov/OGWDW/gapreport.pdfhttps://en.wikipedia.org/wiki/State_Revolving_Fund

CONSUMPTION AND PRICE-The average domestic water use per person in the U.S. is 98-US-gallon (370 L) per day. This is about 2.5 times as high as in England (150 Liter) and three times as high as in Germany (126 Liter).

-In Germany,based on an annual water and sewer bill of 196 euro per person and two persons per household.

-Each Philadelphian uses an average of 300 to 380 liter of water per day.

Sources:https://en.wikipedia.org/wiki/Water_supply_and_sanitation_in_Germany

SUSTAINABILITYGreen Initiatives of Philadelphia Water Department

•Solar Panel Installation

•Sewage Geothermal Installation

•Biosolid Recycling Center

•Green Stormwater Infrastructure

•Biogas Cogeneration Facility:It has been endorsed by EPA(Environmental Protection Agency).

It is able to meet 85% of its electrical requirements for plant operations using biogas cogeneration.

The project cost $47.5 million and was financed by Bank of America, the company which technically owns the facility though the city is leasing it for 16 years.

Sources:http://www.phila.gov/water/sustainability/Pages/default.aspx

THANK YOU !Jesus Ramirez Diaz

Prasad Jagannath Satpute

Ameya Sunil Waghmare

Shreeyog Sadanand RajopadhyeAlperen Yüce