D.Ram Mohan Rao

Associate Prof. in MJ Enagg. College, Banjara Hills, Hyd

SOFT WARE APPLICATIONS WATER SUPPLY SYSTEMS

30-06-2012

Guest Lecture

What we designWater supply(? How much is area)How many people?How much Q we supply?What we require to design & implement?What are precautions required?Is my design optimal?

Water flowOpen channel flow

Pipe flow

Peizometric HeadP/r= pressure head(1)

Z=Datum head(2)

Peizo head=(1+2)

We require elevation****Pressure (Pipe flow)Source of elevation SurveyWhat survey?Not you learned in your( BE or B.tech)Why ?

WATER SUPPLYDATAMAP OF AREAPOPULATIONDEMAND PATTERNELEVATIONS(CONTOUR MAP)ROAD NETWORK MAP

SOFT WARES

1)AUTO CAD LAND DEVRLOPMENT

2)RASTER GIS(EG SAGA – GIS)

(To- day case study)

3)EPANET(WATER SUPPLY)

4) MS – EXCEL

5) SWMM

6)SEWER 3.0

7)OTHER COMMERCIAL SOFT WARES

Pipes are aligned only along ROADSWe need road mapWe require demand & supply( source)Treatment ?(WE leave to others)Where to provide storage (Bank, money bank, may be

Yes)

1)AUTO CAD LAND DEVELOPMENTHow is different from AutocadWhat is terrain analysis?What we require?Map & x,y,z co-ordinatesBuild surface from data,ST we know z for any pointDemo?

Open new dwg & nameSave with name closeOpen again with pre hidden folder to create

project(heigher folder)Project contains many folders like cogoSave with same name

1)AUTO CAD LAND DEVRLOPMENT

1)AUTO CAD LAND DEVRLOPMENT

Import pointsImport points (x,y,z) to dwgBuild surfaceSurface has z at all(x,y)So we know z at all points & junctionsInterpolatin mistakes ?

Saga GIS

DIGITAL ELEVATION MODEL NALGONDA TOWN

ZONE OF TANDUR WITH ROAD NETWORK +LEVELS

Surface viewTIN

DEM

CONTOURS (difficult)

TIN

We will see in demo

Creation of DEM

Software for Decision Making for Design of Sewer System

GENERATION OF DEM(X,Y,Z)

FROM FILE SHAPES IMPORT TO SAGA

OBTAIN DEM FOR REQUIRED GRID SIZE

INTER POLATION -YES

DEM OF STUDY AREA

CALUCLATION OF DEMAND

EXCEL EXAMPLE SIMPLE MODELAPPLICATION ON EPANET

DESIGN OF

WATER SUPPLY SYSTEMS

Components of Water Supply SystemComponents of Water Supply System

1. 1. Intake StructureIntake Structure2. Raw water Storage (optional)2. Raw water Storage (optional)

3. Raw water conveyance3. Raw water conveyance4. Treatment Plant4. Treatment Plant

5. Clear water Storage 5. Clear water Storage 6. Clear water conveyance6. Clear water conveyance

7. Distribution System7. Distribution Systemi. Main or Trunk linei. Main or Trunk line

ii. Branch lineii. Branch lineii. Service lineii. Service line

Intake Structure

Raw Water Storage

Raw Water Conveyance

Treatment Plant

Clear Water Storage – GLSR/ELSR

Distribution Network

S. No. Component Design Period in

years

1 Storage by Dams 50

2 Infiltration Works 30

3 Pump House (Civil Works) 30

4 Pump House (Electrical Works) 15

5 WTP 15

6 Raw water and Clear Water Pipes, Pipe connections to treatment units etc

30

7 Service Reservoirs, Clear water reservoirs 15

8 Distribution System 30

Time lag between design and completion of the project should be between two to five years.

Design Period for various components

Design StepsDesign Steps

Population Estimates

Demand Estimates

Zoning

Feeder Mains

Distribution System

Filter plant with all its components

Population Forecasting Population Forecasting

Based on the following factors:

IndustrialCommercialEducationalSocialAdministrative SpheresSpecial factors like sudden immigration and influx

1. Demographic Method: Arithmetic 1. Demographic Method: Arithmetic Balancing is done by considering the births, Balancing is done by considering the births, deaths, migration. The prevailing and deaths, migration. The prevailing and anticipated birth rates and death rates and anticipated birth rates and death rates and the immigration to the city, growth of city the immigration to the city, growth of city area is taken into account.area is taken into account.

2. Arithmetical Increase Method: Applicable 2. Arithmetical Increase Method: Applicable to large and old cities. The method gives to large and old cities. The method gives low valueslow values

Population Forecasting MethodsPopulation Forecasting Methods

3. Incremental Increase Method: The increment 3. Incremental Increase Method: The increment in arithmetical increase is determined from the in arithmetical increase is determined from the past decades and the average is added to the past decades and the average is added to the average increase.average increase.

4. Geometric Increase Method: This method 4. Geometric Increase Method: This method gives much higher values and is used for gives much higher values and is used for growing towns and cities having vast scope for growing towns and cities having vast scope for expansion. In this the percentage increase is expansion. In this the percentage increase is taken as the rate of growth.taken as the rate of growth.

5. Decreasing Rate of Growth Method: Used 5. Decreasing Rate of Growth Method: Used when the rate of percentage increase when the rate of percentage increase decreases. Used in cities where rate of decreases. Used in cities where rate of growth is negativegrowth is negative

6. Graphical Method: Computed either by 6. Graphical Method: Computed either by considering the city in question alone or by considering the city in question alone or by taking similar cities into consideration. The taking similar cities into consideration. The population curve is smoothly extended for population curve is smoothly extended for getting future values. Method of least getting future values. Method of least squares may be used to get the best fit line.squares may be used to get the best fit line.

8. Logistic Method: The complete trend of 8. Logistic Method: The complete trend of growth of the city from beginning to saturation growth of the city from beginning to saturation limit is obtained as a S shaped logistic curve.limit is obtained as a S shaped logistic curve.

9. Method of Density: Sector wise trend in 9. Method of Density: Sector wise trend in rate of density increase is used to project the rate of density increase is used to project the populationpopulation

FINAL FORECAST: After projecting the FINAL FORECAST: After projecting the population a discerning judgment has to be population a discerning judgment has to be made about the zonal increase based upon made about the zonal increase based upon the master plan.the master plan.

Per capita SupplyPer capita Supply

i. Domestic needsi. Domestic needsii. Institutional Needsii. Institutional Needsiii. Public useiii. Public useiv. Industrial and Commercial iv. Industrial and Commercial UseUsev. Fire Fightingv. Fire Fightingvi. Livestock requirementvi. Livestock requirementvii. Minimum permissible vii. Minimum permissible UFWUFW

Maximum Lpcd

1 Towns with piped WS but no Sewerage System

70

2 Cities with piped WS and Sewerage System

135

3 Metropolitan and Mega Cities 150

In urban areas if water is provided through public stand posts 40 LPCD suffices

Unaccounted for Water should be limited to 15%

Demand includes supply to commercial, institutional and minor industries. Bulk supplies to be assessed separately.

Pressure Requirements Pressure Requirements 24 hour supply 24 hour supply recommendedrecommendedIntermittent supplies not Intermittent supplies not desirable from PH point of desirable from PH point of view and economy.view and economy.One Storeyed buildings – 7 One Storeyed buildings – 7 mmTwo storeyed buildings – 12 Two storeyed buildings – 12 mmThree storeyed buildings 17 Three storeyed buildings 17 mm

Transmission of WaterTransmission of Water1. Open Channel Flow1. Open Channel Flow2. Pressure Conduit Flow2. Pressure Conduit FlowMannings formula for open Mannings formula for open channel and Hazen-Williams channel and Hazen-Williams formula for pressure conduits formula for pressure conduits are popularly used.are popularly used.

Distribution System is designed for hourly variation of flow.Peak Factor

challenges

10/09/10

Thank You

51

Sewer System design

Design Period•Design period of 30 years is recommended in the Manual on sewerage And sewage Treatment by CPHEEO, Government of India. •Sewer are deigned for maximum expected discharge to meet the requirement of ultimate population of the area.•Population existing and anticipated in various zones to be served by a particular sewer is arrived at and designs will be carried for it. •Consideration should be given to the pattern of future development as indicated in town planning schemes. •Load coming on sewerage scheme from industrial units should be taken into consideration and capacities of sewer lines increased accordingly.

Population Forecast : •Forecast population for design period by using standard methods and check the same for its validity. •Where population details are not available, the Manual on sewerage, government of India recommends following densities of population

Density of Population Size of town Population

Density of population per hectare

Up to 5,000 75-1505,000-20,000 150-25020,000-50,000 250-30050,000-100,000 300-350above 100,000 350-1000

Carrying CapacityThe carrying capacity of the sewers is designed on the basis of prospective population and taking into consideration that 80% of water supply (manual of sewerage) will reach the sewer, multiplied by the peak factor (the ratio of maximum to average flows).

Peak FactorContributory Population Peak factor Up to 20,000 3.520,000-50,000 2.550,000-7,50,000 2.25Above - 7,50,000 2.0

Recommended Depth of flow in sewers Due to consideration of ventilation in waste water flow, sewers are not designed to run full. Manual on sewerage recommends the following depth of flow :

Size of Sewer Depth of Flow Up to 400mm dia 4/5 depth above 400 mm dia 4/5 depth

Sizes of sewersMinimum size of sewer : As per recommendations the minm. diameter for public sewer shall be 150mm.In hilly areas where steep slopes are prevalent, minimum size may be 100mm

Minimum And Maximum Velocity Sewers should be constructed with gradients which produce self cleaning velocities sufficient to carry forward all solids and avoid settlements. A minimum velocity of 0.6m /sec should reach at least for present peak flows.

The maximum velocity to be permitted is of the order of 3.0 m/sec.

Manholes Manholes should be provided at all places of start of sewer lines, change of direction, change of gradients, change of size and at junction of two or more sewers. The location of manholes should be at convenient places depending upon the size of the sewer lines. Along straight length of sewers, the Manual on Sewerage recommends that the manholes should be so spaced that maximum distance between manholes should not exceed

Spacing of Manholes : Size of Sewer Maximum distance between manholes

Upto 300 mm dia 30 mLarger Sewers may go upto 100 m or moreManholes shall be ensured to be water tight to exclude any infiltration.

for depth 0.8m or less : 0.75m x 0.75mfor depths between 0.8m and 2.10m : 1.20m x 0.9mfor depths more than 2.1m : Circular chambers with a

min. dia of 1.4 m or rectangular chamber with internal dimensions of 1.2m x 0.9m

Shape and Size of Manholes

The minimum internal size of manholes as recommended by IS1742 are as under:

Saga GIS - TANDUR

GENERATION OF GEM FROM POINT FILE(X,Y,Z)EG

POINT FILE FROM AUTOCAD LDDT

HOW TO ALIGN SEWER LINES ?

Saga GIS

PREPARATION OF DEM WITH HELP OF POINT FILE

SURFACE IS CREATED FROM ELEVATION DATA(FROM TOTAL STATION SURVEY(EG))

CHANGE TO X,Y,Z FORMAT WITHHELP OF

MS EXCEL

WHAT IT’S MEANS WHEN ZOOMED

GRID SIZE 50M X 50M

1) POPLLATION OF TOWN OR CITY

DATA REQUIRED

2) PECPITA WATER SUPPLY

3)ROAD LAYOUT MAP

4) Elevation data ANALYSIS ?

5) MAP OF WATER BODIES

PREPROCESSED DEM REMVAL OF PITS

CATCHMENT AREA AND CHANNEL NETWORK

MAP(EG)

SEWER LINES SHOULD FOLLOW NATURAL DRAINAGE PATTERN(EG)

PREPROCESSED DEM ? REMOVAL OF SINKS(EG)

DERIVATION OF CATCHMENTAREA MANY METHODS, PARALLEL PROCESSING

CHANNEL NETWORK RASRER FORMAT

CHANNEL NETWORK RASRER FORMAT

TRANSFERRING TO AUTOCAD

DISCHARGEON ROAD LAYOUT MAP LOCATE MANHOLESMINIMUM DISTANCECHANGE OF ALIGNMENT JUNCTION OF ROADSCEATE POINT FILE FROM AUTOCAD

LDDT,COVERT TO EXCEL

CALUCLATION OF DISCHARGE

Q/M LENGTH=AREA IN SQ KM*POPULATOIN DES/(LENGTH IN M)*C*PCC

EG AREA =10SQ KM ;L=3000M C=0.8;PD=30000/SQKM;PCC=140L/DAY

Q/M=10*30000*0.8*140/3000=1120L/(DAY*M)=1.12CUM M/(DAY*M)

AUTOCAD LDDT

DRAWING AND PROJECT

DIFFERENCE : 2D AND 3D

TERRAIN MODEL EXPLORER

SURFACE MODEL EG

SMALL DEMO

CONTOURS AND TIN

OTHER SOFTWARES

SEWER 3.0

SWMM

SEWERAGE SYSTEM DESIGN PARAMETERS

Allowable FSI : 1.0Number of persons/Ha : 0.7650 x 10000 x 1.0 / 9.0

: 850 persons /haPer capita Water Consumption : 150 lpdPeak Factor : 2.25Adopted Sewer System : SeparateMaximum allowable Velocity in Pipes For SWG pipes : 3.0 m/s For Cement Pipes : 2.5 m/s

Minm. Velocity adopted : 0.45m/s

Adopted pipes : upto 12” dia SWG Pipes: Above 12” dia Cement Pipes

Minm. Depth of Pipe Invert : 1.0mManhole spacing : maximum 40.0 m in straight run

: Average spacing of Manhole locations 15.0mMinm. Diameter adopted : 200 mmLimitation of the System : Capable of carrying only DWF Flow

SUGGESTIONS GIVEN BY THE HMWS & SB

To consider adjoining Panchayatis/ Cantonment Area load if flowing

towards Municipality

Per Capita Water Demand as 150 lpcd instead 100 lpcd for DWF

estimations (Krishna Water Support)

To treat sewage to river standards (BOD < 20mg/l ) before treated

effluent reaches open drains/ lakes)

Design Period as 2031

To ensure existing open Nallahs clear from encroachments if possible to

construct Pucca Open Drains for Storm Water and for treated water

Isolated Sewage Treatment Plants are economical if maintained properly

(Reduces Trunk and Sub Main Dias Significantly)

GREEN HYDERABAD ENVIRONMENT PROGRAMME (GHEP)

87 Lakes were selected for Development in GHEP Project

Two Lakes namely Maisamma Tank and Ranga Raidu were selected for development in Kukatpally Municipality

Development includes Construction of Sewerage Treatment Plant and open drain for surplus water to connect to downstream lake/river/ nallah.

DISPOSAL POINTS IN THE PROJECT INFLUENCE AREA

ZONING SYSTEM FOR PROJECT INFLUENCE AREA

LOCATIONS OF PROPOSED SEWERAGE TRETMENT PLANTS

CRITERIA OXIDATION POND

ASP MOVING BED REACTOR

Rating on scale of 10( Maximum)

COMPACTNESSArea Required

1 5 10

Simplicity 10 3 4

Noise free Operation

10 3 6

Odour free Operation

4 7 10

Variable Hydraulic Loading.

10 3 8

Ease of Sludge handling

4 8 6

Power consumption 10 2 2

Total Rating 7.0 4.42 6.57

STANDARDS FOR SEWERAGE TREATMENT PLANTS/PONDS

Types of Reuse Treatment Water Quality

Agricultural irrigation with restricted access of fodder,fiber, seed crops, sod farms, Pasture land, and areas with restricted public access.

Secondary and chlorination or storage ponds with 25 days of detention time

<30 mg/l BOD, <30 mg/l SS, and <200/100 ml fecal coliforms

Agricultural irrigation of food crops commercially processed and foods eaten raw and irrigation of orchards and vineyards

Surface Irrigation: Secondary,disinfection Spray Irrigation: Secondary,coagulation,filtration,disinfection

<30 mg/l Bod, <30 mg/l SS, and <23/100 ml Fecal Colifoirms <10 mg/l Bod <2 NTU, and <2.2/100 ml fecal coliforms

Urban irrigation with restricted access such as golf courses, cementeries and roadway medians

Secondary and disinfection <10 mg/l BOD, <10 mg/l SS, and <23/100 ml fecal coliforms

Urban reuse with unrestricted access, such as irrigation of parks, residential, and commercial areas

Secondary, coagulation, filtration, disinfection

<10 mg/l BOD, <2 NTU, and <2.2/100 ml fecal coliforms

Industrial reuse for cooling water, pulp and paper, textiles and similar applications

Secondary and disinfection <10 mg/l BOD, <10 mg/l SS, and <23/100 ml fecal coliforms

Groundwater recharge and potable water reuse by subsurface injection and short detention surface water

Secondary, lime coagulation, filtration, carbon adsorption, disinfection and possible reverse osmosis

<0.5 NTU, <2 TOC, <1000 TDS, zero fecal coliforms, and meeting other drinking water standards.

UNDER GROUND SEWERAGE SYSTEM FOR KUKATPALLY MUNICIPALITY

ZONEWISE LENGTHS OF PROPOSED UGD SYSTEM

Group/ Zone

900 mm dia.

750 mm dia.

600 mm dia.

450 mm dia.

300 mm dia.

250 mm dia.

200 mm dia

Total Length

1. Zone-1 11.10 1.10 3.83 6.57 12.05 21.91 23.01 41.09 109.57

2. Zone-2 7.48 0.00 0.69 2.07 6.89 17.90 16.52 24.79 68.85

3. Zone-3 7.36 0.00 0.63 1.90 6.32 16.43 15.17 22.75 63.19

4. Zone-4 7.60 0.00 0.83 2.50 8.32 21.62 19.96 29.94 83.17

5. Zone-5 2.69 0.00 0.00 0.00 4.66 8.15 9.31 16.69 38.81

6. Zone-6 1.22 0.00 0.00 0.00 1.25 2.19 2.51 4.49 10.45

7. Zone-7 0.98 0.00 0.00 0.00 1.29 2.26 2.59 4.64 10.78

8. Zone-8 4.98 0.00 0.61 1.84 6.13 15.95 14.72 22.08 61.34

TOTAL 43.41 1.10 6.60 14.87 46.91 106.43 103.79 166.46 446.16

LENGTH OF PROPOSED SEWERAGE SYSTEM (km.)Sl. No.

Area (Sq.km.)

UNDER GROUND SEWERAGE SYSTEM FOR KUKATPALLY MUNICIPALITY

ESTIMATED COST (SSR 2003-’04, Hyderabad, West Circle)Group/ Zone

900 mm dia.

750 mm dia.

600 mm dia.

450 mm dia.

300 mm dia.

250 mm dia.

200 mm dia

Total

1. Zone-1 11.10 43 141 205 225 238 178 278 1308 368 1677

2. Zone-2 7.48 0 25 64 128 195 128 168 709 248 957

3. Zone-3 7.36 0 23 59 118 179 118 154 650 244 894

4. Zone-4 7.60 0 31 78 155 235 155 202 856 252 1108

5. Zone-5 2.69 0 0 0 87 89 72 113 361 89 450

6. Zone-6 1.22 0 0 0 23 24 19 30 97 40 138

7. Zone-7 0.98 0 0 0 24 25 20 31 100 33 133

8. Zone-8 4.98 0 23 57 114 174 114 149 631 165 796

TOTAL 43.41 43 243 464 875 1158 804 1125 4712 1440 6152

STP Cost - Secondary (Rs. Lakhs)

TOTAL COST

(Rs. Lakhs)

Sl. No.

Area (Sq.km.)

COST OF PROPOSED SEWERAGE SYSTEM (Rs. In Lakhs)

Note : STP proposed is Secondary Level (BOD < 20 mg/l, river/lake standard)

Urban reuse with unrestricted access, such as irrigation of parks, residential, and commercial areas.

FINANCIAL RESOURCES MOBILISATION

Kukatpally Municipality = Rs. 12.00 Cr.

Mega City Fund = Rs. 10.00 Cr.

Users’ Contribution = Rs. 10.00 Cr.

A.P.Government Grant = Rs. 25.00 Cr(Through Sale of open land by District Collector, R.R.District )

GHEP- HUDA = Rs. 5.00 Cr.

TOTAL = Rs. 62.00 Cr.

NOMENCLATURE OF SEWERS

SLDISTANC

ECUM.

NUMBER OF

TRIBUTED

TOTAL TOTAL TOTAL SEWAGE CUMILAT

IVEGROUND

CUM GROUND

ULTIMATE

NOIN

DISTANCE

PLOTSINCREAM

ENTALCUMILAT

IVEPOPULATIO

N

CUM POPULATI

ONFLOW SEWAGE WATER WATER

AVERAGE

FROM TO

(IN Mt.) SERVING AREA AREA(@115

persons/Ha.)

(@ 115 persons/Ha.

)

INCREMNTL @80%

of 125Lt/Cap

ita.

FLOW @80% of

125 Lt/Capita

INFILTRATION @

10000 Ltr/Ha

INFILTRATION @

10000 Ltr/Ha

FLOW

(IN Mtr) (In Hect) MLD MLD IN (MLD) IN (MLD) IN (MLD)

1 2 2 3 4 5 6 7 8 9 10 11 12 13 14 151 2A2B MH12 0 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.0002 2A2B MH12 MH11 30 30.000 6.562 0.072 0.072 8.301 8.301 0.001 0.001 0.001 0.001 0.0023 2A2B MH11 MH10 30 60.000 6.562 0.072 0.144 8.301 16.601 0.001 0.002 0.001 0.001 0.0034 2A2B MH10 MH9 30 90.000 6.562 0.072 0.217 8.301 24.902 0.001 0.002 0.001 0.002 0.0055 2A2B MH9 MH8 30 120.000 6.562 0.072 0.289 8.301 33.202 0.001 0.003 0.001 0.003 0.0066 2A2B MH8 MH7 30 150.000 6.562 0.072 0.361 8.301 41.503 0.001 0.004 0.001 0.004 0.0087 2A2B MH7 MH6 30 180.000 6.562 0.072 0.433 8.301 49.803 0.001 0.005 0.001 0.004 0.0098 2A2B MH6 MH5 30 210.000 6.562 0.072 0.505 8.301 58.104 0.001 0.006 0.001 0.005 0.0119 2A2B MH5 MH4 30 240.000 6.562 0.072 0.577 8.301 66.404 0.001 0.007 0.001 0.006 0.01210 2A2B MH4 MH3 30 270.000 6.562 0.072 0.650 8.301 74.705 0.001 0.007 0.001 0.006 0.01411 2A2B MH3 MH2 30 300.000 6.562 0.072 0.722 8.301 83.005 0.001 0.008 0.001 0.007 0.01612 2B2C MH2 MH1 30 330.000 6.562 0.750 1.472 86.250 169.255 0.009 0.017 0.008 0.015 0.032

DISTANCE

PRESENT FLOW DESIGN CALCULATIONS

SLDISTANC

ECUM.

NUMBER OF

TRIBUTED

TOTAL TOTAL TOTAL SEWAGECUMILAT

IVEGROUND

CUM GROUND

ULTIMATE

NOIN

DISTANCE

PLOTSINCREAM

ENTALCUMILAT

IVEPOPULAT

IONCUMILAT

IVEFLOW SEWAGE WATER WATER

AVERAGE

FROM TO

(IN Mt.) SERVING AREA AREA(@224

persons/Ha.)

POPULATION

INCREMNTL @80%

of 150Lt/Cap

ita.

FLOW @80% of

150 Lt/Capita

INFILTRATION @ 10000 Ltr/Ha

INFILTRATION @ 10000 Ltr/Ha

FLOW

(IN Mtr) (In Hect) SERVING SERVING MLD IN (MLD) IN (MLD) IN (MLD)

1 2 2 3 4 5 6 7 8 17 18 19 20 21 22 231 2A2B MH12 0 0.000 0.000 0.000 0.000 0 0.000 0.0000 0.000 0.0000 0.000 0.00002 2A2B MH12 MH11 30 30.000 6.562 0.072 0.072 18 18.261 0.0022 0.002 0.0007 0.001 0.00293 2A2B MH11 MH10 30 60.000 6.562 0.072 0.144 18 36.522 0.0022 0.004 0.0007 0.001 0.00584 2A2B MH10 MH9 30 90.000 6.562 0.072 0.217 18 54.783 0.0022 0.007 0.0007 0.002 0.00875 2A2B MH9 MH8 30 120.000 6.562 0.072 0.289 18 73.045 0.0022 0.009 0.0007 0.003 0.01176 2A2B MH8 MH7 30 150.000 6.562 0.072 0.361 18 91.306 0.0022 0.011 0.0007 0.004 0.01467 2A2B MH7 MH6 30 180.000 6.562 0.072 0.433 18 109.567 0.0022 0.013 0.0007 0.004 0.01758 2A2B MH6 MH5 30 210.000 6.562 0.072 0.505 18 127.828 0.0022 0.015 0.0007 0.005 0.02049 2A2B MH5 MH4 30 240.000 6.562 0.072 0.577 18 146.089 0.0022 0.018 0.0007 0.006 0.023310 2A2B MH4 MH3 30 270.000 6.562 0.072 0.650 18 164.350 0.0022 0.020 0.0007 0.006 0.026211 2A2B MH3 MH2 30 300.000 6.562 0.072 0.722 18 182.612 0.0022 0.022 0.0007 0.007 0.029112 2B2C MH2 MH1 30 330.000 6.562 0.750 1.472 190 372.362 0.0228 0.045 0.0075 0.015 0.0594

DISTANCE

PROJECTED FLOW DESIGN CALCULATIONS

Column – 2: MANHOLE NUMBER OF UPSTREAM POINT – MH 12

Column – 3: MANHOLE NUMBER OF DOWNSTREAM POINT – MH 11

Column – 4: DISTANCE BETWEEN THE MANHOLES – 30 mt

Column – 5: CUMULATIVE DISTANCE BETWEEN THE POINTS – 30 mt

Column – 6: NUMBER OF PLOTS

ASSUMING EACH PLOT SIZE 40’ X 30’

FOR ONE PLOT = 30 X .3048 = 9.14 mt

NO. OF PLOTS = 30’ X .3048 X 30 mt

FOR 30 mts = 30/9.144 = 3.28 No’s

CONSIDERING PLOTS ON BOTH SIDES OF THE ROAD

SO 3.28 X 2 = 6.56 No’s

COLUMN – 7: AREA OF PLOT PER HECTARE = 30’ X 40’ X .3048 X .3048/10000 = .011 HecSO TOTAL AREA CONTRIBUTED IN THAT SEWER = .011 X 6.56 = 0.072 Hec

COLUMN – 8: CUMULATIVE AREA CONTRIBUTE

COLUMN – 9: PRESENT POPULATIONPOPULATION DENSITYTOTAL POPULATION OF THE ZONE / TOTAL AREA OF THE SLUM = TOTAL AREA IS 8000 HECTARES TOTAL POPULATION IS 70 PERSONSPOPULATION DENSITY = 80 X 70 = 115 PERSONS PER HECTARE NUMBER OF PERSONS ALONG THAT SEWER = 0.072 X 115 = 8.28 PERSONS

COLUMN – 10: CUMULATIVE POPULATIONCOLUMN – 11: CONSIDERING PERCAPITA DEMAND 150 LPCD

80% OF 150 LPCD WILL COME TO THE SEWER = 80% X 150 = 120 Lts.

COLUMN – 11: CONSIDERING PERCAPITA DEMAND 150 LPCD 80% OF 150 LPCD WILL COME TO THE SEWER = 80% X 150 = 120 Lts. TOTAL SEWER CONTRIBUTE = 120 LPCD X 8.3 = 997.2 Lts. = 0.000997 MLD

COLUMN – 12: CUMULATIVE SEWAGECOLUMN – 13: GROUND WATER INFILTRATION

CONSIDERING GROUND WATER INFILTRATION 10,000 Lts. PER HECTARE 0.072 X 10,000 = 720 Lts. PER HECTARE = 0.00072 MLD

COLUMN – 14: CUMULATIVE GROUND WATER INFILTRATIONCOLUMN – 15: TOTAL SEWAGE = COLUMN 14 + COLUMN 12COLUMN – 16: CONSIDERING PEAK FACTOR AS 2.25

ULTIMATE PEAK FLOW = COLUMN 12 X 2.25 + COLUMN 14 0.000997 X 2.25 + 0.00072 = 0.00296 MLD

CALCULATIONS FOR PROJECTED POPULATIONS

COLUMN 1 TO 8 SAME AS ABOVECOLUMN – 17: PROJECTED POPULATION

CONSIDERING RATE GROWTH AS 25% AND DESIGN PERIOD OF 30 YEARS AS PRESENT POPULATION DENSITY = 150 PERSON PER HECTARE PROJECTED POPULATION = 150 X 1.25 X 1.25 X 1.25 = 225 PERSONS PER HECTARE

COLUMN – 18: CUMULATIVE POPULATIONCOLUMN – 19: SEWAGE CONTRIBUTION FOR PROJECTED POPULATION

225 X 120 = 27,000 = 0.027 MLDCOLUMN – 20: CUMULATIVE SEWAGECOLUMN – 21: SAME AS COLUMN 13COLUMN – 22: SAME AS COLUMN 14

COLUMN – 23: ULTIMATE SEWAGE FLOWCOLUMN – 24: CONSIDERING PEAK FACTOR AS 2.25 X COLUMN 19 + COLUMN 13

= 2.25 X 0.0027 + 0.00072 = 0.0061 MLDHYDRAULIC CALCULATIONS

CALCULATE THE SLOPE ACCORDING THE GROUND CONDITIONS IN THIS CASE ASSUMING SLOPE AS 200 TAKING MINIMUM DIAMETER AS PER CPHEEO 200 mm

AS THE FLOW IS OPEN CHANNEL FLOW CONSIDER MANNINGS EQUATION I.e. V = 1/n R2/3 S1/2

n = 0.013SLOPE = 1/200 = 0.0005R = A/P A = AREA OF SEWER = 3.14 / 4 X 0.2 X 0.2 = 0.0314P = WETTED PERIMETER = 3.14 X 0.2 = 0.628A/P = 0.05A/P^2/3 = 0.135S^1/2 = 0.07V = 1/0.013 X 0.07 X 0.135 = 0.726Q FULL = DISCHARGE = V X A

0.726 X 0.0314 = 0.022 CUM / SEC

Q ACTUAL FOR PRESENT = 0.00296 X 1000/24 X 3600 = 0.000034 CUM/SECQ ACTUAL / Q FULL = 0.000034/0.022 = 0.0015 v/V = 0.3d/D = 0.07SELF CLEANING VELOCITY = v/V X V = 0.07 X 0.726 =0.22

Q ACTUAL FOR PROJECTED = 0.0061 MLD = .0061 X 1000 / 24 X 60 X 60 = 0.000072 CUM/SECQ ACTUAL / Q FULL = 0.003

FROM THE TABLE S d/D = 0.30 v/V = 0.07

SELF CLEANING VELOCITY FOR PROJECTED = 0.51 X 0.564 = 0.22

Pre-Construction Tests1. Diameter of pipe 7. Brick Size2. Length of pipe. 8. Brick Strength.3. Strength of pipe. 9. FRC Frame and Cover.4. Acid Resistance. 10. FRC Frame and Cover Strength.5. Alkali Resistance. 11. Cement Quality.6. Water Absorption. 12. Sand Quality.

Post- Construction Tests.1. Edge protection and finishing of manhole cover, /frames & Covers.2. Lifting Hooks.3. Load Test.

Scale of sampling for load test DimensionRequirment Upto 100 manholes 2 10101 to 200 3 15201 to 300 4 20301 to 500 5 30

4. Water flow test5. Ball test6. Smoke test

PRACTICAL HINTS FOR DESIGNING A SEWERAGE SCHEME

General : While designing a sewerage system, the following points should kept in view :

(a)the out –fall point should be very carefully selected first and then adhered to strictly. While selecting the out fall points, the direction of wind should also be kept in view so that waft of bad odour are avoided. All town improvement and town planning schemes should be carefully considered so that shifting of out-fall point with the growth of town in that directions is avoided.(b)The scheme should be started from out fall end so that sewers may be utilized from the beginning, thus ensuring that the functioning of scheme has not to wait for till the completion of the entire scheme.(c) The scheme should be planned in progressive stages so that investment yield benefits from the beginning. To ensure that various stages fit in the main scheme, the scheme should be planned as a whole and various stages worked out thereafter.(d)Method of treatment or disposal should be decided while preparing the project, instead of postponing it till the completion of the scheme.(e)Sewerage should not be introduced without ensuring adequate water supply.

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