“Lake Protection (Bandhwa Talab) through Decentralised

Wastewater Management”

“Lakes Bio-Remediation Project”

WIPRO Corporate Office, Sarjapura, Bangalore

25th November 2014

Presented by Andrews Jacob

Introduction to the Project

Current Sanitation Situation

Wastewater Management

Concept (DEWATS)

2

PRESENTATION OUTLINE

INTRODUCTION TO PROJECT AREA3

BANDHWA TALAB

Surface Area- 23,602 sq.mt.

Maximum depth- 230 cm

Status-

• North Eastern edge- Untreated wastewater flow

from adjacent Residential area, and surface

drains convey solid waste

• South East-an outflow drain present. Mainly

used for laundry washing, fishing and religious

activities

• Western bank- Temple complex

• South Eastern and South Western bank used

for laundry washing

• Fishing activities all around the lake.

View on the eastern bank of Bandhwa Talab with

lake water overrun at the north-eastern edge and

rampant water vegetation.

Bathing activities at the south-eastern bank. This

part is free of water vegetation.

DEMOGRAPHY & LANDUSE4

The catchment covers:

POPULATION- 916 persons

HOUSES-124

HOUSEHOLDS-171

AVERAGE HH SIZE-5

LANDUSE:

Residential-89%

Mixed-5%

Commercial- 5%

Institutional-2%

5

WASTEWATER MANAGEMENT - MAP

6

COVERAGE OF SEPTIC TANKS EFFLUENT DISPOSAL FROM SEPTIC TANK

WASTEWATER MANAGEMENT

CURRENT SANITATION SITUATION…

CONVEYANCE SYSTEM

Wastewater from households discharged into

drains constructed for carrying storm water.

Total drain length in the catchment area

approximately 1000 meters with depth varying

from 0.3 to 0.8 meter

Type of existing drains are as follows:

Open Drains- 45%

Partially covered-26%

Fully Covered-22%

The overall condition of storm water drains is

poor with more than 50% of total drain length

clogged with solid waste.

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CURRENT SANITATION SITUATION…

8

DETAILS OF WATER BALANCE IN BANDHWA TALAB

CURRENT SANITATION SITUATION…

9

QUALITY OF WASTEWATER

INFLOW AT BANDHUA TALAB:

Chemical Oxygen Demand

(COD) -310 to 1183 mg/l.

Biological Oxygen Demand

(BOD) -103 to 392 mg/l.

AT BYPASS:

COD -734 to 1550 mg/l and

BOD -234 to 512 mg/l

BANDHWA

TALAB

BYEPASS

CURRENT SANITATION SITUATION…

Wastewater quality analysis conducted

during period May-July 2012

CONCEPT FOR WASTEWATER MANAGEMENT10

Finalised Concept

The above mentioned concept was approved by RMC Officials on 20/12/2012

and the decentralised technology for wastewater treatment selected was

DEWATSTM for its low O&M cost in comparison to the other technologies.

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POTENTIAL OF DIFFERENT TREATMENT OPTIONS

Criteria SBR DEWATS FAB

Performance in Terms of Quality of Treated Sewage

Potential of Meeting the TSS, BOD, and COD

Discharge Standards

Potential of Total / Faecal Coliform Removal

Potential of DO in Effluent

Potential for Nitrogen Removal (Nitrification-

Denitrification)

Potential for Phosphorous Removal

Performance Reliability

Potential of Low Energy Requirement

Potential of Low Land Requirement

Potential of Low Capital Cost

Potential of Low Recurring Cost

Potential of Low Level of Skill in Operation

Potential of Low Level of Skill in Maintenance

Potential Low Medium High Very High

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Catchment population - 1000 people

Water Supply - 135 lpcd (based on the service level

benchmarks as mentioned in the CSP for Raipur City).

Wastewater generation - 85% of water supply i.e. 114.75 cu.m

per day (say 115 cu.m/day)

Composition of wastewater

67% greywater, 33% blackwater.

Greywater generated - 76.38 cu.m/day (say 77 cu.m)

Blackwater generated - 37.86 cu.m/day (say 38 cu.m/day)

INPUT DATA FOR DPR

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Wastewater parameters for designing of treatment unit

INPUT DATA FOR DETAILING CONCEPT

Parameter Grey Water

Blackwater

(effluent from

septic tank)

Combined

(grey+black)

Biological Oxygen Demand (BOD)

mg/L

100 - 150 300 - 450 200 - 400

Chemical Oxygen Demand (COD)

mg/L

200 - 300 600 - 900 400 - 800

Total Solids mg/L 500 - 700 800 - 1000 100 - 150

Total Nitrogen mg/L 0.05 - 0.15 0.05 – 0.15 0.15 – 0.20

Phosphates (as P) mg/L 3.00 – 5.00 5.00 – 10.00 10 - 15

Coliform (MPN/100 ml) 1600 > 1600 1000 - 1600

Based on wastewater quality analysis conducted during period May-July 2012

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locations for installation of

treatment unit

Two potential sites available for

installation of treatment unit.

Preferred location - land identified in

the northern part of Bandhwa Talab

(Site A) close to the inlet point

The other location is a low lying area

in the north eastern part of the lake

(Site B).

DETAILS OF DPR

SITE ‘A’

SITE ‘B’

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Stakeholder Workshop

“GIZ Support to the NUSP – CSP Implementation” 9th April 2013, Raipur

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Stakeholder Workshop

“GIZ Support to the NUSP – CSP Implementation” 9th April 2013, Raipur

18

Stakeholder Workshop

“GIZ Support to the NUSP – CSP Implementation” 20 December 2012, Raipur

Proposed Network for Conveying Wastewater

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Treatment and Disposal

The quantum of wastewater to be treated is estimated to be 115 cu.m.

The wastewater shall be treated using a DEWATSTM technology to a

level prescribed by PCB and shall be discharged into Bandhwa Talab

DETAILS OF FINALISED CONCEPT…

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Decentralised Wastewater

Treatment System (DEWATSTM)

The wastewater collected through the

SSS shall be conveyed through the

following modules for treatment:

Settler – Primary treatment

Anaerobic Baffled Reactor (ABR) –

secondary treatment and organic reduction

upto 90% can be achieved

Anaerobic Filter (AF) - further 70-90% of the

remaining organic load

Planted Gravel Filter (PGF) –tertiary

treatment for further removal of organic load

and nutrients present in the wastewater

DETAILS OF TREATMENT TECHNOLOGY

Collectio

n Tank

Pump wastewater to Lake

Sedimentation tank for retaining settleable particles

Dissolved and suspended matter passes untreated to

next stage of treatment

Efficiency of 25% - 40%

Desludging period of 2 years as per design for

sludge storage

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Raw

Sewage

Partially Treated

Wastewater

Sludge Sludge

Scum

Biogas

Gas

TREATMENT MODULE 1 - SETTLER

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Gas Gas Partially Treated

Wastewater

TREATMENT MODULE 2 – ANAEROBIC BAFFEL REACTOR +

ANAEROBIC FILTER

Activated

Sludge

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Anaerobic Baffle Reactor (ABR):

• Anaerobic treatment (in the absence of oxygen)

• Wastewater passes a series of up-flow chambers

• Bacteria mass (activated sludge) at bottom of each chamber

• Further treatment (degradation) of suspended and dissolved solids by

anaerobic bacteria

• Efficiency 75% - 85%

Anaerobic Filter (integrated with ABR)

• Wastewater passes in a series of up-flow chambers with carrier

material (filter material)

• The filter is made out of gravel, slag or plastic elements

• To avoid plugging pre-treatment (sedimentation) is necessary.

• Efficiency 75% - 90%

TREATMENT MODULE 2 – ANAEROBIC BAFFEL REACTOR +

ANAEROBIC FILTER…

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TREATMENT MODULE 3 – PLANTED GRAVEL FILTER

Aerobic treatment (in the presence of

oxygen)

Planted Gravel Filter (PGF) consist of plants

(reeds) & filter materials (graded gravels,

river pebbles)

The filter is permanently soaked (up to 50

cm from bottom) in water

The flow direction is horizontal

Wastewater requires pre-treatment

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O&M

Desludging of settler Wastewater Monitoring

Cleaning of filter material Plant harvesting for PGF

Treatment is based on physical and

biological (anaerobic and aerobic)

wastewater treatment component

Affordable price

Fulfillment of discharge standards

Treatment of wastewater flows from 1-1000

m3/d

Tolerance to inflow fluctuation

No dependence on external energy

Minimal and easy maintenance

Reliability and long-lasting

Reuse of wastewater

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ADVANTAGES OF DEWATS TECHNOLOGY

THANK YOU…

Consortium for DEWATS Dissemination (CDD) Society

Survey No. 205, (Opp. Beedi Workers Colony)

Kommaghatta Road, Bandemath

Kengeri Satellite Town

Bangalore 560 060 – Karnataka, India

Tel/Fax: +91-080-28486700 / 28482144

www.cddindia.org

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