Liquid Waste Management for Rural India

16 July 2016

www.wsp.org | www.worldbank.org/water | www.blogs.worldbank.org/water | @WorldBankWater

16 July 2016

Shrikant Navrekar

What is Liquid Waste ?

Water wasted as a result of various human activities at home, in businesses & in industries is called Liquid Waste

OR

2

OR

Used & unwanted waste water generated in household or Commercial activities is called Liquid Waste.

Liquid Waste is also called Waste Water

Types of Liquid Waste / Waste Water

Liquid Waste / Waste Water

Domestic Waste Water Commercial Waste Water

Black Water Grey WaterWaste Water from

1. Small scale industries2. Hotels3. Hospitals4. Slaughter houses5. Laundries

• Black Water : Water from toilets / contaminated with fecal matter

• Grey Water : All other waste water (from kitchenbathroom, cloth wash, vessel wash )

In Rural India : LWM = GWM

Source of waste water Type of waste water

1. Toilets Black water

2. Bathroom Grey water

3. Kitchen Grey water3. Kitchen Grey water

4. Washing cloth Grey water

5. Washing animals Grey water

• Generation of Grey water is almost to the tune of 70 to 80 % of the fresh water coming in a household.

Current Practices : Grey Water

• Indiscriminate disposal in the open

• Open or Surface drainage system

• Unscientific kitchen garden

• Unscientific soakage pits• Unscientific soakage pits

Current Practices : Black Water

• Effluent from Septic Tank Toilets

• Discharged in the open • Discharged in open drain

Basic Principles of Waste Water Management

1. Judicious use of fresh water : Minimum Generation of

waste water

2. Separation of Black Water (if any) & Grey Water2. Separation of Black Water (if any) & Grey Water

3. Reuse of Waste Water to maximum possible extent

4. Treatment of Waste water at nearest possible point from

the point of generation / adopt Decentralized systems.

Decentralized v/s Centralized Systems

Decentralized Systems Centralized Systems

1. Soak pits, Leach Pits, Kitchen Gardens at HH level

1. Drains + Treatment units like Waste Stabilization ponds

2. Low capital cost 2. High Capital cost2. Low capital cost 2. High Capital cost

3. Low maintenance cost 3. High Maintenance cost

4. Maintenance also decentralized : by the HH owner

4. Maintenance centralized needs to be done by GP

5. No centralized space required 5. Centralized space required for treatment unit

Criteria for selection of Technology

1. Availability of space near houses & housing pattern

2. Geophysical condition of the village including

topography, soil structure & ground water conditions

3. Sources of water & pattern of water supply (individual / 3. Sources of water & pattern of water supply (individual /

public)

4. Availability of common spaces in & around the village

5. Economic status of the GP & human resource

available with the GP

Criteria for selection of Technology

Criteria for selection of Technology

Technological Options at a Glance

Grey Water

(A) Management at Domestic level (B) Management at Community level

(B.2) Grey Water from houses managed collectively

(B.1) Grey Water at Public PlacesLike Hand pumps, stand posts,

wells etc

How to Select a Technology : General strata

Space at HH

Inadequate spaceInadequate space

Permeable SoilPermeable Soil Leach PitLeach PitPermeable SoilPermeable Soil Leach PitLeach Pit

Semi Permeable Soil / B.C. SoilSemi Permeable Soil / B.C. Soil Modified Leach PitModified Leach Pit

Impermeable SoilImpermeable Soil

Space with Space with Permeable Soil nearbyPermeable Soil nearby

No Space nearbyNo Space nearby

Community Leach pit for Community Leach pit for group of housesgroup of houses

WSP / Reed Bed System WSP / Reed Bed System / DEWATS/ DEWATS

Domestic Level Management (On site )

1. Kitchen Garden

Silt chamber /Grease trap

Nhani Trap

Domestic Level Management (On site )

Domestic Level Management (On site )

Magic Pit

Domestic Level Management (On site )

Domestic Level Management (On site )

2. Magic Pit

Domestic Level Management (On site )

2. Magic Pit

1. Anaerobic condition inside the pit

2. Periodical cleaning essential

3.Cleaning is not easy3.Cleaning is not easy

4. Gravels required

Domestic Level Management (On site )

2.Leach pit

1. Less excavation

2. No filling with gravel

3. No stagnation of water3. No stagnation of water

4. Less maintenance

Community Level Management (Off site )

Community Leach Pits for a group of houses

Community Level Management (Off site )

1. Community Leach Pits for a group of houses

2. DEWATS Systems like Reed Bed, Anaerobic Baffled Reactor etc2. DEWATS Systems like Reed Bed, Anaerobic Baffled Reactor etc

3. Waste Stabilization Ponds

Components of Community Level Management

1. Transport of Grey Water preferably through pipes

2. Intercepting chambers at intervals2. Intercepting chambers at intervals

3. Final treatment Unit

Components of Waste Stabilization System

1. Transport of Grey Water preferably through pipes

Components of Waste Stabilization System

2. Intercepting chambers at intervals

Components of Waste Stabilization System

3. Final treatment Unit

Comparison of Technologies based on Capex / Opex

Technology Capex Opex

Kitchen Garden Low Low

Leach Pit at HH Low Low

Community L.P. for a Community L.P. for a Group of Houses

Moderate Moderate

Waste Stabilization Pond

High High

DEWATS / PhytoridModerate to

highModerate to

high

Urine : The Orphaned Waste

• Urine : A principal liquid waste of human origin

• Urinal not essential in HH with toilets

• Urinals are essential at public places

- Not adequate- Not adequate

- Not maintained properly

- Urine is generally discharged in the open / open drain

- Precious source of organic manure is wasted

• Provision of Scientific urinals should be an integral part

of LWM at village level

Indicators for an Ideal LWM Village

I. Physical Indicators

a. Dry Environment

b. Mosquito Free Environment

c. Pig Free Premisesc. Pig Free Premises

Indicators for an Ideal LWM Village

Type of Waste

Water

Indicators

Black Water

1. Zero generation of black water (adoption of toilet types

which do not generate waste water)

2. If at all black water is generated

- It is not let in the open / open drainsBlack Water - It is not let in the open / open drains

- It is not flown into water bodies

- Treated properly either in individual leach pits or

common treatment units

Grey Water

1. Less quantity generated : Judicious use of fresh water

2. Not let in the open / open drains

3. Treated properly either in individual kitchen gardens /

leach pits or in community type treatment units as per the

situation.

Indicators of an Ideal LWM Village

Type of Waste

Water

Indicators

Commercial /

Industrial

1. Treated / contained / reused as per the

existing laws & rulesIndustrial

waste water

Yellow Water

(Human Urine)

1. Not let in the open / open drains / water

bodies

2. Scientific design of public urinals adopted

3. Proper containment (in leach pits / soak

pits) & or Treatment & use in agriculture

Comparison of CAPEX & OPEX for a few treatment options

S.No Wastewater treatmentCapital cost

(Rs/HH) O&M cost (Rs/HH)

1Leach pits

(individual / community)3000 – 15,000 # Negligible

2 DEWATS * 13,500 – 32,500/HH 145 – 630/HH

3Conventional sewer

and waste stabilization ponds

41,000 – 112,000(174 – 744 HH §)

400/HH

Notes:1. # - individual and serving 5 households2. * - Costs provided by CDD; 100 – 1000 households3. § - Data from Punjab

IMPLEMENTATION

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LWM through SBM (G) : Challenges

1. Ignorance at various levels

2. Negligent Attitude of the society

3.3. Inclination towards urban model

4. Sustainability- the biggest challenge

LWM through SBM (G) : How do we go ?

1. Selection of right technology

2. Strict adherence to technological standards

3. Concurrent Quality monitoring

4.4. Effective O & M

5. Involvement of people from level zero

Institutional Arrangements for LWM

1. SLWM resource team at State level:

2. SLWM resource team at District level:

3. Explore need for qualified persons/group at GP for O&M and enable GP to make provision

4. Involve SHGs, other community groups, and 4. Involve SHGs, other community groups, and private sector / entrepreneurs for SLWM as Village Level Sanitarian (service provider)

5. Enable basic monitoring/recording systems at GP level for identified indicators through SBM-G

“ It is easier to organize a seminar on sanitation

than to bend down & pick up a chocolate wrapper ”

“ Be the change that you wish to see in the society “

Thank you

Shrikant Navrekar

safaiwala@gmail.com

www.wsp.org | www.worldbank.org/water | www.blogs.worldbank.org/water | @WorldBankWater

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