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Grey WaterManagementin Rural India
Grey WaterManagementin Rural India
Ministry of Drinking Water and Sanitation
Solid and Liquid Resource Management
Solid and Liquid Resource Management
Ministry of Drinking Water and Sanitation
Grey WaterManagementin Rural India
Grey Water Management in Rural India
ii
DISCLAIMER AND NOTICE TO READER
The information provided in this book is designed to provide helpful information on the subject discussed. The comments received during consultation will be considered during the final preparation of the thematic resource book. The content, structure, form and wording of the this consultation draft are subject to change as a result of the consultation process and as a result of review, editing and correction by Ministry of Drinking Water and Sanitation.
The information contained herein is subject to change and does not commit MDWS for any factual error.
Grey Water Management in Rural India
iii
Swachh Bharat Mission has been able to achieve significant strides over the last 4 years by providing access to toilets to underserved areas and encouraging their sustainable use. More than 600 districts in India are now ODF with toilet coverage of nearly 99 % in rural India. As we chart the course ahead for SBM and increasing ODF coverage in India, it is an opportune moment to develop a comprehensive framework for one of the ODF sustainability and ODF plus activities, namely Grey Waste Management (GWM) in rural areas. It has emerged as a major problem in rural areas and the issue of its management will also become challenge overtime. As population in India is forecasted to experience an unprecedented growth from currently 1.31 billion to 1.65 billion by 2030, the management of Greywater in rural areas needs innovative solutions to address the challenge. There needs to be a development of management strategy in order to stop unsafe and hazardous methods of disposal of greywater.
Organizing grey waste management activities in rural areas will reduce the burden on the fresh water supply and augment water for non-potable domestic purposes. With appropriate policy nudges, these can be scaled up into opportunities addressing water stress in rural India. This GWM document serves as a platform for building a rural implementation framework for Greywater Management to various stakeholders from Gram Panchayats (GPs) districts and States across India. Each technological solution explored here addresses the challenges present and recommends solutions for sustainable water management. Through this document, MDWS aims to create an action plan and way forward for Greywater Management and bring forward various policy frameworks, technologies for rural areas. Implementation of suggested action plans and technologies would make an important contribution towards transforming this important sector by augmenting additional water.
Concrete and game-changing steps have to be taken for Greywater management to achieve the goals anchored in this document. Ministry would like to thank wholeheartedly the support, objectives and comprehensive action plan / way forward provided by various intellectuals, organizations, departments and institutions for Greywater management in Rural India. We would like to thank Mr. Dinesh Mehta (Professor, CEPT University), Ms. Meera Mehta (Professor, CEPT University), Dr. Rajesh Biniwale (Scientist, NEERI), Mr. M Subburaman (SCOPE, Trichy), Prof. Vivek Kumar (Associate Professor, IIT Delhi), Mr. Rajiv Mehta (ADC, Panipat) and Mr. Shrikant Navrekar (Nirmal Nirman Kendra). The Ministry would also like to acknowledge UNICEF, TATA TRUSTS and M/s Dalberg who were principally involved in framing this document.
PREFACE
Grey Water Management in Rural India
iv
Grey Water Management in Rural India
v
1. Managing Grey Water In Rural India 1
1.1 Grey Water Profile in Rural India 1
1.2 Characterisation of Waste Water 2
1.3 Quantity of Greywater Generated in Rural India 3
1.4 Effect of Greywater on Health and Environment 5
1.5 Benefits of Greywater Management 6
2. Policy Background 7
2.1 International Comparison 7
3. Key Challenges and Opportunities 9
4. Technical Options for Greywater Management 10
5. Implementing Grey Water Management in States & Districts 18
5.1 Implementation Framework for District 18
5.2 Guiding Principles 28
5.3 Guidelines for State 29
6. Grey Water Strategy 32
Annexure A 35
Annexure B 60
Annexure C 67
Annexure D 69
CONTENTS
Grey Water Management in Rural India
vi
Grey Water Management in Rural India
1
Context
Grey water is the category of waste water that is not contaminated with faecal or urinal matter. This broad category includes post-use water from most domestic purposes like bathing, washing dishes, laundry etc.
Most rural areas in the country let domestic run-offs of grey water collect in open areas, or flow into water bodies. This is, in part, responsible for an environment where diseases and pathogens breed.
While substantially less harmful than black water (water that has been contaminated by faecal matter), grey water still contains potentially hazardous chemical and biological particles. Additionally, untreated grey water is a wasted resource, that could have been used to provide relief from acute water stress in many parts of India.
If harnessed with the right scientific techniques, grey water can become a potent resource for several non-potable uses, if treated with care. This document attempts to lay the background for why grey water requires immediate attention, and how states and districts can chart their course on the journey to attaining sustainable grey water systems.
The document is organized into four sections that covers
An overview of grey water in India
Existing government policy and international landscapes
A range of technical and operational models for managing Grey water
Strategy and implementation framework for State, District and Gram panchayat levels.
1.1 Grey Water Profile in Rural India
Domestic waste water in rural areas can broadly be categorized as grey and black water, not counting agriculture or industrial waste water which tends to have a very chemical-heavy mix. At institutional and community toilets facilities, significant quantum of yellow water is generated.
MANAGING GREY WATER IN RURAL INDIA1
65-70% of the total water supply in rural areas is converted to grey water after use.
Grey Water Management in Rural India
2
Grey water in households gets generated as a by-product of processes such bathing, laundry, cooking, washing utensils, washing livestock. Black water, on the other hand, is waste water that is contaminated with faecal matter and urine. In this note, we address the challenges and opportunities of dealing with grey water.
The composition of grey water, naturally, is substantially different form black water. It contains only about a tenth of the nitrogen found in black water. There is a much decreased load of pathogens in grey water than black water. As a result, the organic content of grey water decomposes more rapidly than black water and thus treatment is easier. These features make it usable as a sustainable source of irrigation, provided it meets quality criteria.1
Source of Waste Water
Greywater is waste water from bathroom, washing of clothes and kitchen. Depending on its use.
Water can require less treatment than black water & Treated water can be reused
Generally contains fewer pathogens
Black water is water that has been mixed with waste from the toilet.
Black water requires biological or chemical treatment & Treated black water requires disinfection before re-use
Black water contains higher level of pathogens
Source of Black Water
Toilet
Source of Greywater
Washing Clothes KitchenBathroom
1 “Grey water use standards and prospects”, Oren et al, Water Research 2014
1.2 Characterisation of Waste Water
Greywater is the reflection of household activities, its main characteristics strongly depend on the factor such as cultural habits, living standard household demography, and type of household chemical use. Grey water is the least contaminated type of waste water which needs very
less degree of treatment.
Typically grey water contains Total solids (TS), Total Suspended Solids (TSS) which are bigger than 0.2µm, settleable and colloidal solids. Grey water contains 60% to 70% of readily degradable organic solids and 30% of inorganic solids. The inorganic fraction is mostly sand and grit that settles to form and inorganic sludge layer. Total suspended solids comprise both settleable solids and colloidal solids. Suspended solids can be easily removed through settling or filtration
Grey Water Management in Rural India
3
2 Format B1- Basic Habitation Information, National Rural Drinking Water Programme, MoDWS,
Organic Constituents
Biodegradable organic compounds are mainly composed of proteins, carbohydrates and fats. If discharged untreated into the environment, their biological stabilization can lead to the depletion of natural oxygen and development of septic conditions.
Inorganic Constituents
Nitrogen and Phosphorus are the two essential nutrients present in greywater. Greywater contains 10% or less than 10% of nitrogen of total water system and 10% to 30% of phosphorus of total water system. Nitrogen and Phosphorus, also known as the nutrients are essential for the growth of micro-organisms, plants and animals. When discharged into the aquatic environment, these nutrients can lead to the growth of undesirable aquatic life, which rob the water of dissolved oxygen which when discharged in excessive amounts on land they can lead to groundwater pollution.
Turbidity and organic solids deplete the oxygen level and prevent light from penetrating in to the water body, this causes death of aquatic life.
Grey water Black water
Chemical
Contaminants
Fats, Oils and toxic substance (organic compounds, Chlorides metals etc)
Micro contaminants (Heavy metals)
Biological
contaminants
Almost Sterile (If not cross contaminated by faeces
Pathogens (Bacteria, Viruses, Helminths, Protozoa)
Value Reuse potential (For irrigation or non-potable domestic use)
Good soil conditioner but only little nutrients
Potential Risk and Benefit comparison between Grey water and Black water
1.3 Quantity of Greywater Generated in Rural India
Rural area in India is supplied with an average 50 litres2 of water per capita per day. 65% to 70% of total water supplied to rural India is converted into grey water. On the basis of quantity of water supplied, rural India on an average generates about 31,000 Million litres of grey water on a daily basis. This primarily includes waste water from the kitchen, bathroom and laundry. The volume and nature of grey water varies with lifestyle of the population.
Rural India on an average generates about 31,000 million litres of grey water on a daily basis.
Grey Water Management in Rural India
4
One extremely important determinant of the volume and nature of waste water is economic status and access to water sources. In less-affluent communities with poor access to water, quantities typically range from 20 to 30 litres/person daily.3 The volume increases to approximately 100 litres/person in developing areas. In fully urbanized regions, it is in the range of 100 to 200 litres/day.4
The census 2011 revealed that only 37% of the rural households have drainage inside their premises. State-wise generation of liquid waste is given below:
9727
3124
10000
5000
0
Uttar P
rades
hBiha
r
Mad
hya P
rades
h
Gujarat
Mah
arash
tra
Wes
t Ben
gal
Andhr
a Prad
esh
Odisha
Rajasth
an
Tam
il Nad
u
Karnata
ka
NE States
Jhark
hand
Haryan
a
Kerala
Chhatt
isgarh
Hilly Stat
es
Punjab
Telan
gana UT
Goa
31222792
2013 1994 1794 1757 1744 1674 1357 1235 1186 1184 1065 1065 927 796 70553 49
Liquid waste generation by states in MLD
Total liquid waste generation in rural India– 39,337 MLD
Seven states generate ~ 2/3rd of India’s total liquid waste generation
Liquid waste generation (MLD) across stataes
Source: Format B1- Basic Habitation Information, National Rural Drinking Water Programme, MoDWS, GoI http://indiawater.gov.in/imisreports/Reports/BasicInformation/rpt_RWS_AbstractData_S.aspx?Rep=0&RP=Y&APP=IMIS, accessed on 17.2.18
Further, there are 2,55,576 Gram Panchayats in the country. A profile of liquid waste generated in these Panchayats indicates that 19% of large Gram Panchayats generate nearly 50% of the waste, as given in the figure below..
3 WHO, Ridderstolpe 20044 WHO, Crites and Tchobanoglous 1998
Note: For the purpose of comparison, liquid waste generation is considered that inter-alia includes grey water.
Grey Water Management in Rural India
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5 UN report on water-borne diseases 20106 Census 2011
1.4 Effect of Greywater on Health and Environment
Grey water is hazardous by nature and a breeding ground for diseases. Grey water, when mixed with faecal matter and other toilet waste, becomes black water, and carries a substantially greater threat of disease.
Current practices in managing grey water in rural needs improvement. There is indiscriminate disposal of liquid waste in open areas. Vector-borne diseases like malaria, polio, dengue and cholera are largely dependent on stagnant grey water. At the turn of this decade, these diseases were directly responsible for the deaths of one lakh people every year in India.5
Drains in rural areas are not common. 63% of rural households don’t have drains within their premises.6 31% of households have open drains, leaving them susceptible to dumping of other kinds of waste. Only 6% of households actually have closed drainage systems. Drain construction is often faulty and improper, leading to cracks and leaks. There is also misuse of drainage systems, as unintended leakages lead to mixing of grey water with faecal matter.
Large GPs (19%) generate nearly 50% of liquid waste
100%
50%
0%
8%
45%
47%
7%
38%
55%
28%
Population Share
53%
19%
No. of GPS – 247,00 Population – 92 Crore Liquid waste generated – 39,337 MLD
Medium GPsLarge GPs >5,000 Small GPs <1.500
Distribution of GPs Share of Liquid waste generation
Source: Format B1- Basic Habitation Information, National Rural Drinking Water Programme, MoDWS, GoI http://indiawater.gov.in/imisreports/Reports/BasicInformation/rpt_RWS_AbstractData_S.aspx?Rep=0&RP=Y&APP=IMIS, accessed on 17.2.18
Note: For the purpose of comparison, liquid waste generation is considered that inter-alia includes grey water.
GREY WATER HAS TRADITIONALLY
BEEN MANAGED IN RUDIMENTARY AND
UNSAFE WAYS IN RURAL AREAS, WITH
INDISCRIMINATE OPEN DUMPING AND
DISCHARGE INTO WATER BODIES
Grey Water Management in Rural India
6
Even where drains exist in rural areas, they often empty directly into water bodies without treatment. This, hazardous grey water poses serious risks of contamination of surface as well as ground water, particularly in areas with high water tables.
1.5 Benefits of Greywater Management
Treated grey water provides an opportunity for decreasing the water stress in the country through its reuse for non-potable purposes and for ground water recharge. This is particularly important given India’s growing need for water. Moreover, materials found in grey water become pollutants when they join larger water bodies or are allowed to stagnate, but if integrated with the soil system, they can act as a source of nutrition.
In some developed countries, households and communities are effectively able to integrate their grey water into irrigation systems in kitchen gardens as well as public parks, provided their processes meet the standards set out by agencies. The most common example is a holding tank connected to standard drainage pipes that deliver waste water (meeting the standards notified by competent authorities) to the roots of trees and other large plants. While these solutions are challenging to implement in India, they serve as an extremely useful opportunity in water-scarce rural areas. Effective policy design and technical intervention can turn the challenge of managing grey water into a resource.
Thus, grey water, if managed safely and scientifically, has the potential to be used in:
Kitchen gardens
Non-potable domestic use like washing and cleaning.
Under certain specific contexts, irrigation in agricultural fields as well
Recharging ground water.
Gap in the closed piped drainage systems in rural areas leads to mixing of waste water types and contamination of water resources and spread of pathogens.
IF HANDLED SCIENTIFICALLY, GREY
WATER COULD EASE SOME OF
THE DEMAND FROM FRESH WATER
RESOURCES, PARTICULARLY IN WATER
SCARCE AREAS
Grey Water Management in Rural India
7
Under Swachh Bharat Mission (G) and earlier guidelines, liquid waste management is part of a larger portfolio of duties meant to be enacted by the Gram Panchayats.
There are guidelines and standards regarding the treatment and reuse of blackwater.
Central Public Health and Environmental Engineering Organization (CPHEEO) has specified discharge standards for treated black water. They permit the use of this water in agriculture and horticulture.
Central Pollution Control Board (CPCB) has also issued standards for the disposal of treated black water.
Central Ground Water Board (CGWB) advocates treated black water can be used as a source of artificial ground water recharge, once it meets standards and is compatible with existing ground water.
Ministry of Environment, Forests and Climate Change has issued waste water reuse policies with discharge and reuse standards.
2.1 International Comparison
There are some important lessons from policy and technological interventions made by other countries.
United States:
Regulation on water reuse is under the jurisdiction of states and territories. The federal government released an updated document called “Guidelines for Water Reuse 2012” on the available technologies and key implementation considerations
The use of grey water hinges on standards accepted by environmental agencies, and stipulations on processes as well as design guidelines that help achieve these standards
Certain specific states like Wyoming allow for surface and sub-surface irrigation using greywater
Other states like Montana have passed bills allowing for greywater use by multi-family and commercial complexes
POLICY BACKGROUND2
Grey Water Management in Rural India
8
Governments in arid and semi-arid regions in Arizona, California and Texas have been providing financial incentives for the installation of grey water reuse systems in new residential homes.7
Australia
Australia issued “Guidelines for Water Recycling: Managing Health and Environmental Risks” to encourage the setting up of grey water management systems
The government gives grants of AUD 500 for households setting up small-scale piped systems
Regulations allow for the use of this water in gardens, lawns and laundry, depending on the level of treatment it has undergone
Other Developed Countries
In Tokyo, it is mandatory for buildings with an area of over 30,000 m2 to install grey water systems
Some municipalities in Spain have passed regulations to promote grey water reuse in multi-storeyed buildings8
Evidently, these formalized policies are largely a feature of developed countries recognizing the paucity of fresh water sources. One interesting intervention in decentralized grey water solutions in rural areas can be found in Israel and the West Bank.
The Centre for Transboundary Water Management (CTWM) is developing technologies to reduce pollution caused by unsafe disposal of grey water, as well as increasing the water supply to rural communities.
West Bank is a largely remote, extremely water scarce region. CTWM’s technologies hold the potential to reduce domestic water consumption by 40% by reusing treated grey water in irrigation.
There are six water recycling treatment centres in the area, of varying sizes and technologies. Most plants are funded through external grants and operated by families who are able to sustain growing fruits and crops that are sold in local markets.
7 Oren et al 2014 8 Ibid.
Grey Water Management in Rural India
9
Grey water management models have failed to scale up in India. There are substantial impediments to the widespread acceptance of these technologies. Some of the important barriers these interventions face are:
Behavioural barriers on reuse of greywater is to be overcome to drive household and community level technologies to success. This will require motivating the need and value for these technologies.
Though there is provision for construction of household level soak pit and leach pit for greywater management under government schemes, due to lack of awareness.
Huge stress is given on construction of drainage systems to carry greywater out of habitational area without providing a specific discharge point or treatment facility.
More and more funds have been utilised for construction of drains without preparation of master plan and without having technical knowledge to construct.
Poor or absence of solid waste management in the village has led to clogging of drains therefore making drains dysfunctional and the gram panchayat’s have been spending major portion of its fund on cleaning these drains.
In certain villages, there is direct discharge of black water directly in to drains.
There is a lack of institutional support at the GP and district level to do feasibility analyses for where these technologies are most suitable, what conditions are required for their success, and what operational models guarantee sustainability and success.
Given the intricate nature of waste water treatment technologies, community members, operators, and entrepreneurs will require training on technical and operational models.
Many grey water management technologies such as ponds, wetlands, small bore sewers, drains require frequent O&M. Typically, this has been a challenge as not enough resources or monitoring has been set aside for this at the Gram panchayat level.
KEY CHALLENGES AND OPPORTUNITIES3
Grey Water Management in Rural India
10
Grey water composition varies by region and concentration. In industrial areas, it is likely to be dominated by hazardous metallic and chemical waste that is challenging to treat for. In rural areas, the use of detergents and synthetic cleaning agents is considered to be limited. The contamination in grey water is likely to be from organic waste and fertilizers. International agencies like WHO, as well as India’s CPCB, recommend stringent safety standards for the reuse of contaminated waste water. It is imperative that these standards are met post-treatment, before this water enters food supplies and shows downstream effects.
Grey water management in rural areas requires special attention, since most of the commonly suggested urban interventions are infeasible and unlikely to be successful in these contexts. For instance, high capital investment and expenditure on maintenance of closed drain systems is perhaps unjustified given the low rates of per-household water discharge will not be able to sufficiently cater to the high end technology models. There are several feasible alternatives, including small bore drainage systems that are cheaper and less invasive.
TECHNICAL OPTIONS FOR GREYWATER MANAGEMENT4
Technology
On site
Household Community Village
Off site
Soak pit
Leach pit
Magic pit
Kitchen garden
Community Soak pit
Community Leach pit
Community level wet land
Community Kitchen garden
Small Bore System (Conveyance system)
Waste Stablisation Ponds
Duck Weed Pond System
Constructed Wetland
Soil Bio Technology (SBT)
Phytorid Technology
Anaerobic Baffled Reactor (ABR)
Moving Bed Bio-Film Reactor (MBBR)
Technology Options for Greywater Management
Grey Water Management in Rural India
11
There are menus of options available at the household, community and village level, all offering cost-effective treatment systems. While soak pits, leach pits and kitchen gardens are suggested at individual household levels, larger community pits and wet lands are suggested at the community level. At the village level, the Gram Panchayat can invest in bigger initiatives such as duck weed pond systems, Phytorid-based technologies and waste stabilization ponds.List of technology option under three implementation level for greywater management is shown below.
Deciding Parameters for Choosing Level of Greywater Technology
Solutions
Technology options for greywater management depends on various parameters, these parameters becomes significant to choose the level of technology intervention to be adopted at three implementation level such as house hold, community and village level. A compendium on these technologies is at Annexure A.
Sl.
No
Parameters for selecting level
of grey water management
intervention
Household-
level solutions
Community-
level solutions
Village-level
solutions
1 Quantity of Grey water generation Low Medium High
2 Favourable soil condition Yes Yes No
3 Ground water level condition Low Low High
4 Availability of space at individual House Hold
Yes No No
5 Availability of community space No Yes No
6 Existing drain Network No No Yes
Suitability of level technology implementation may vary according to various scenario. Given the diversity in geographical conditions and habitational density across the country, suitability of greywater management solutions also varies accordingly. The following matrix presents different technical and operational options suitable for these varied scenarios. These choices will inform the overall implementation framework for the districts.
The technical options recommended are:
1. Soak pits
2. Leach pits
3. Magic pits
4. Kitchen garden
5. Community soak pit
6. Community leach pit
7. Community wet land
Grey Water Management in Rural India
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8. Community kitchen garden
9. Waste Stabilisation Ponds
10. Duck Weed Pond System
11. Constructed Wetland
12. Soil Bio Technology (SBT)
13. Phytorid Technology
14. Anaerobic Baffled Reactor (ABR)
Scenarios9 Household-level
solutions (Soak
pits)
Community-
level solutions
Village-level
solutions
Bulk-
generator
solutions
Peri-urban, high settlement density, low availability of free land
L M H H
Rural, high-settlement density, low availability of free land
M H H M
Rural, low-settlement density, higher availability of free land
H M M L
Tribal H M L L
Mountainous H M L M
High water table area L L H M
Region with Hard rock strata L L H H
L: Low suitability, M: Medium suitability, H: High suitability
9 Peri-urban areas are more densely populated than rural areas, and it is likely that households will be closely spaced leaving very little free-space for household level grey-water solutions. Tribal areas are likely to be sparsely populated, and have little community level infrastructure such as drains. Mountainous regions need a special focus since their terrain is not suitable for several technologies.
Technology Capex Opex Management capacity
HH/community Level
Kitchen Garden
Leach Pit/Magic Pit at HH level
Community Leach Pit
OFF Site
Waste Stabilization pond
DEWATS/Phytorid
Low Medium Very HighHigh
Comparison of Technologies Based on Capex/Opex
Grey Water Management in Rural India
13
10 Dr Dinesh Mehta (2018), Current scenario of Grey water management in rural India (PPT), National consultative workshop on SLRM, MDWS, CEPT University, 23rd Feb 2018
Factors10 Deciding Offsite Treatment Technology
1 24 5
3
Distance of
treatment site Land availability
Neighbourhood Geological
parameters
Reliability of
electricity
• Long distance: costly
• A site that is too far away implies fewer trips per day, less revenue and more fuel costs to private operators
• Government land availability
• GP should also explore the possibility of developing septage treatment facility at solid waste dumping or
treatment site
• A treatment site may generate nuisance,
especially bad odours
• It should be located at an appropriate distance from
the residential areas
• Groundwater table
• Type of soil
• Flood-prone area
• If treatment technology has mechanical operated parts
Technology Summary for Grey Water Management
Technology Overview Merit Challenges
Soak Pit- Leach Pit- Magic Pits
A soak-Leach-Magic pit is a pit technology option where Pre-settled effluent from a Collection and Storage/Treatment or (Semi-) Centralized Treatment technology is discharged to the underground chamber from which it infiltrates into the surrounding soil.
Low cost and easy to construct
Dry environment: the entire wastewater from a household is absorbed by this underground structure. This results in dry premises;
One of the demerit is possibility of ground water contamination especially in the areas with high ground water table.
Grey Water Management in Rural India
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Technology Overview Merit Challenges
As wastewater percolates through the soil from the pit, small particles are filtered out by the soil matrix and organics are digested by microorganisms. Thus, soak pits are best suited for soil with good absorptive properties; clay, hard packed or rocky soil is not appropriate
Freedom from the mosquito nuisance; and Odor-free environment;
No drains required
Recharge of ground water O&M costs are low and borne by the house owner.
Pit technologies fail in the areas with hard rock due to low or zero leaching effect of water in to the ground
Operational Life of pit technology drastically decreases without provision of Nhani trap or screening medium to separate out heavy solids.
Constructed Wetlands
Constructed wetlands (Phytorid) are cost-effective engineered systems based on phytoremediation that are considered eco-friendly proposition for wastewater treatment particular at community level and in rural areas
The systems based on natural treatment methods have distinct advantages over conventional treatment plants in terms of low capital cost, easy to construct, simple to operational and maintain and are robust in performance irrespective of input variations.
The technology is suitable for varying capacities ranging from household level to 8-10 MLD.
Low O&M makes technology more applicable in rural and per urban setting besides Urban settlement
Minimum or no use of electricity
No chemical additions
Unskilled manpower required
Resembles garden and therefore adds to aesthetics
Requires larger space
Requires periodic maintenance
Waste Stabilization Pond Technology
WSPs consist of man-made ponds in which different types of wastewaters are treated by naturally occurring processes.
Easy and inexpensive to operate and maintain
Resistant to organic and hydraulic shock loads
Requires large land area
High capital cost depending on the price of land
Requires expert design and construction
Grey Water Management in Rural India
15
Technology Overview Merit Challenges
They are especially appropriate for rural communities that have large, open and unused lands, away from homes and public spaces and where it is feasible to develop a local collection system.
WSP systems comprise a single string of anaerobic, facultative and maturation ponds in series or several such series in parallel
High reduction of solids, BOD, and pathogens
No electrical energy required
No real problems with flies or odors if designed and maintained correctly
Can be built and repaired with locally available materials
Effluent can be reused in aquaculture or for irrigation in agriculture
Sludge requires proper removal and treatment
De-sludging (normally every few years)
Mosquito control required
Not always appropriate for colder climates
Ponds present the risk of becoming helminth disease reservoirs
Soil Bio-Technology (SBT)
Soil biotechnology (SBT) is a green engineering approach for wastewater treatment and recycling. It offers the wastewater treatment using bacteria, earthworms and mineral additives in a garden-like setup.
SBT is an oxygenation engine that outperforms conventional technologies like Activated Sludge Process (ASP), Sequential Batch Reactor (SBR), Membrane Bio Reactor (MBR) and Moving Bed Bio reactor (MBBR). Life of filtering media bed is long and requires minimal maintenance, more reliable and it is energy and cost efficient.
The process can be run on decentralized or centralized mode in batches or in continuous mode both.
Mechanical aeration is not required.
Cost effective compared to conventional technologies, 10000 times more effective in bacterial removal and 100 times more effective in COD removal.
100 % of treated water is being reused in horticulture. The revenue from horticulture comes to Rs. 1.5 Lakh p.a.
Marginally higher capital requirement (~1.3 times)
Bigger land area requirement
Grey Water Management in Rural India
16
Technology Overview Merit Challenges
No toxic waste and foul smell is produced.
No sludge production
Phytorid Technology
Phytorid technology is developed by NEERI for sewage treatment NEERI is a government research institute under Council of Scientific and Industrial Research.
The sub-surface flow type, Phytorid system is proposed for the treatment of sewage or domestic wastewater which will consists of a basin or a channel with a barrier to prevent seepage, but the systems / cells / beds contain a suitable depth of porous media.
The vegetation to be utilized for the said Phytorid system is very important. Various species of aquatic plants have been utilized to attain maximum efficiency in the treatment of domestic wastes.
It is a very cost effective technology when compared with the traditional wastewater treatment methods.
Since it utilizes natural vegetation and rhizosphere microorganisms, it is eco-friendly method of treating sewage.
An important factor to be considered is the aesthetic improvement that is provided by this methodology.
No mosquitoes and odour nuisance.
The treated water can be used for enhancement of environmental architecture such as roadside fountains.
The quality of treated water is comparable to irrigation standards.
Operation of Phytorid technology requires certain level of management skills
Maintaining uniform flow across the Phytorid system through inlet and outlet adjustment is extremely important to achieve the expected treatment performance.
Sampling of inlet and outlet has to be carried out for a period of 3 months every fortnight after stabilization of the treatment systems of first one year.
Grey Water Management in Rural India
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Technology Overview Merit Challenges
Duckweed Technology
The duckweed based waste water treatment system in conjunction with pisci-culture is one such technology that has the potential of offering effective waste water treatment besides providing economic returns as well as generating employment opportunities in the rural areas.
Duckweed is a small free-floating and fast growing aquatic plant.
Duckweed has the capability to purify wastewater in collaboration with both aerobic and anaerobic bacteria.
Inexpensive to construct and operate, and easy to implement.
Less sensitive to low temperature, high nutrient levels, pH fluctuations, pests and diseases compared to other aquatic plants.
Nutrient removal.
Yield of highly protein containing vegetative material (35 45%) which can be used as animal feed.
Duckweed as an excellent feed for poultry
Tangible economic returns from sale of raw or processed weed or fish
Duckweed is a prolific plant, especially in nitrogen-rich environments, and can be easily used as mulch or for natural soil (organic) enrichment.
Low pathogen removal due to reduced light penetration
Duckweed die off in cold weather condition
Treatment capacity may be lost during high floods, if the area is not protected.
Grey Water Management in Rural India
18
This section of the document outlines guidelines for grey water management at different levels:
1. The strategy for implementation of grey water at country level can focus on priority states on the basis of quantum of generation of grey water. Seven States namely Uttar Pradesh, Bihar, West Bengal, Gujarat, Andhra Pradesh, Bihar and Madhya Pradesh generate about two-thirds of the grey water generation in the country. Further, at GP level, 19% of the large GPs generate 50% of the grey water. Works in these seven States and GPs can be taken up on priority.
2. Implementation framework for District Collectors. A detailed implementation framework covers the sequence of steps district administrators need to take, and assists them with the various considerations they will have to make.
3. Guiding principles. At the outset, this document establishes key features around which specific interventions can be built.
4. Guidelines for State SBM directors and Secretary Drinking Water. This part of the document provides a template for state SBM directors to follow such that constituent districts and GPs can attain a sustainable grey water waste management system.
5.1 Implementation Framework for District
District administrators should adopt a 5-stage approach highlighted in Figure 4 below, to implement effective and sustainable grey water management in their districts and ensure successful outcomes. While the process outlined is largely uniform across districts, administrators should adapt this to local conditions as necessary.
IMPLEMENTING GREY WATER MANAGEMENT IN STATES & DISTRICTS
5
GOAL: To implement a district-wide IEC campaign that focuses on highlighting greywater waste as one the important element which effect public health in rural area and also as a key resource and gets households and farms to adopt effective practices and engage with the treatment and collection value chain.
Step 1: Implement Greywater Waste Management Focused
Iec & Bcc
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A) Current Status
a) Lack of segregation of black water, grey water, agricultural and livestock waste water, industrial waste water within GPs
b) Mixing of grey water and black water along with clean water in drains and also surface water sources (such as ponds, rivers)
c) Household and community level grey water disposed of in proximate areas without proper treatment leading to high levels of contamination and health issues
d) Low willingness to pay for grey water management services and a poor understanding of the value of grey water waste.
B) Key Challenges
Households and farms might not see immediate value (economic, environmental, or health) in carrying out effective practices for greywater management
Behavior might be difficult to switch even if awareness is built up.
Revenue model of community level grey water management may not be profitable/break even always for a GP/village and a portion of recurring operation cost need to be considered for state finance or other fund
1Implement IEC & BCC
2Selection of GP/village
3Diagnostic & Planning
5Implement
Robust Monitoring &
Evaluation
4Implementation
Phase
ImplementIn-situ Grey Water Solution
4a
Implement Grey Water Solution at
Community/Village Level
4b
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C) Technical & Operational Methods
District administrators can adopt a two-pronged approach to promote awareness and behaviour change within their district
1. IEC Campaigning
Grey water management should be part of District Communication Plan under District ODFS AIP
Introduce greywater management in ODF villages with core team or resource group for technical experts and master trainers and mentors for greywater management activities within the district
Encourage all players within district to introduce FSMto all HHs through respective channels
Sensitise and train team on greywater management as a viable option to enhance quality of living standards and as potential source of water.
Train Master Trainers and Community Mobilizers including Swachhagrahis on the concept of house hold greywater treatment technologies such construction of soak pit, leach pit and magic pit.
Build a platform for cross- learning and knowledge sharing
Approved IEC materials emphasizing the value of grey water generated by both farms and households should be created and disseminated through community radio, village level advertising on walls, posters, school curriculum, community meetings hosting by the Panchayats.
The IEC materials should also very prominently highlight the penalties associated with not carrying out appropriate waste management practices including segregation at source.
Masons:
While training masons on toilet retrofitting and augmentation campaign, additional training on integrated technologies and indigenous system of grey water management can be imparted.
Refer to greywater technology manual prepared by MDWS for right technology and design specification.
Highlight importance of Nhani trap and other key elements in the design to enhance life of pit technologies.
Build greywater solutions according to terrain and use of proper technologies
Facilitate participatory approach in designing and construction of these assets. Masons should consult with the stakeholders to minimise occurrence of faulty designs
2. Incentives & Penalties
District administrators can launch a series of incentives and penalties that would reward and recognize villages and village leaders who implement highly effective IEC programs within
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their GPs. Incentives could include “named rewards”, village development funds. Penalties could include “reverse leader boards” that would highlight the least performing GPs in the district.
The GPDP (as outlined in Section 6.1) needs to be reviewed at Block and District levels by the Officers concerned to ensure that grey water management works are included as part of the plan and funds allocated to them. Surpanches who give priority to these works can be motivated through trainings involving visits to other States for cross learning and awards.
D) Tools & Mechanisms That Can Help
IEC Activities
The IEC manuals for programs such as SBM can be used for these activities.
Educational programs undertaken at schools, Gram Sabha meetings, IVR and SMS campaigns, painting at the village level, where households that segregate waste can be recognized as well
Triggering tools used within sanitation including the transect walk in GPs and villages. These will involve community members and help identify challenges, opportunities and develop a common motivation for solid waste management.
GOAL: To decide upon criteria for selection of GPs where grey water management should be focused
Step 2: Selection of Gram Panchayat
A) Current Status
The Districts and the GPs in the districts could have different types of drinking water supply arrangement such as piped water supply, Supply through tanker, Open well, Public tap or well based on which demand for grey water management is decided
B) Typical Challenges
Seasonal variation of water supply for a GP/Village could be there due to which quantity of grey water generation could also vary therefore demand for grey water management vary accordingly
Also, coastal villages and places with higher rainfall requires certain prioritization
There are high chances of mixing of faecal matter with grey water in non ODF villages. This will increase the concentration of contaminants/Pathogens in grey water.
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C) GP Selection for Grey Water Management
The first selection criteria for the district collector/CEO to choose GPs for grey water management is, the village should be ODF and the second most important criteria is to see if there is sufficient demand for grey water management in the village. This could be known by looking at the type of water supply system the village has adopted. At the same time there should demand from GP and GP is ready to allocate a centralised place for treatment
A village having piped network water system will have more potential to generate grey water than the villages dependent on hand pump, well, pond, lakes for their daily water supply.
First priority could also be given to the GPs where natural water resources such as lake, Pond River are being polluted by discharge of untreated greywater into itmainly in the downstream of any industry which discharges effluent
D) Selection Tools
ODF status of a District/village could be known from MIS portal of Swachh Bharat Mission (Gramin)
Water supply status of a GP could be known in Format B1- Basic Habitation Information Under , National Rural Drinking Water Programme, MoDWS, GoI
Data from the VSI can be used in this assessment.
GOAL: To assess the existing status of grey water waste in the district and develop an overall plan for grey water waste.
Step 3: Diagnosis & Planning
A) Current Status
The district and GPs in the district are likely to have a large, highly variable amount of untreated grey water being disposed and mixed in local groundwater or surface water
Grey water is likely to be mixed with other types of waste water with higher levels of contamination (toilet water or agricultural waste water and even industrial waste water)
There is likely to be a lack of data around the extent of this problem
There is likely to be poor awareness and sensitization of households and farms around effective and safe grey water management practices
There is likely to be a nascent and largely informal grey water management supply chain comprising of operators and cleaners responsible for maintenance of village level drains etc.
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B) Typical Challenges
The waste mix is likely to be heterogeneous and surveyors are likely to need sharp focused questions and some calculations to determine the actual quantity of grey water
Responses from houses and farms are likely to be wide ranging in their exactness and hence sampling will become important
The informal service providers are typically not organized under an umbrella organization in the district.
C) Diagnostic Methods and Early Planning
District administrators can use a three-part diagnostic framework to carry out supply and demand side assessments that look at the extent of grey water supply, the availability of service providers for waste water management, and attitudes, behavioral patterns of the communities in order to develop implementable plans and business models.
i. Existing Situation Analysis
The district and GPs in the district should quantify the quantity of grey water generated from the GP based on the quantity of water supplied to the village and consumption pattern.
Identify discharge points in the villages where grey water is entering in to the surface water or ground water body and in open field through transit walks
Grey water is likely to be mixed with other types of waste water with higher levels of contamination such as black water from toilet.
Understand Ground water level conditions and soil type of the village to decide up on choice of technology to be implemented. Support from agriculture department could be taken to understand the soil conditions of the region.
Analyse availability of existing infrastructure such as drain coverage, land obtainability at household and at the village level, in the village to support planning of grey water management.
A sample of households and farms can be chosen to understand existing behaviours around grey water waste management, attitudes and perceptions around different aspects of grey water waste, and finally willingness to participate in different kinds of solutions that might involve expenditure of time and money.
ii. Supply Side Assessment for Grey Water
In the district, a representative sample of formal and informal workers and firms involve in the grey water waste sector can be interviewed to understand their existing work, volume of work, key challenges, financial flows, and the willingness to participate in different technical and operational models. Elements to consider would be the number of sanitation workers in the GP, number of informal workers in GPs. Also it is important understand the current grey water technology widely being used in the district and its success for better planning.
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iii. Behaviours & Attitudes Measurement
A sample of households and farms can be chosen to understand existing behaviours around grey water waste management, attitudes and perceptions around different aspects of grey water waste, and finally willingness to participate in different kinds of solutions that might involve expenditure of time and money
D) Planning Tools
District administrators can make use of
Data from the VSI can be used in this assessment
The diagnostic and planning can be carried out through the GPDP plan
Participatory Rural Appraisal techniques such as feedback sessions, transect walks, social mapping, focus group discussions, ecograms among others
GOAL: To maximize in-situ treatment of grey water waste within households and of farm grey water (cattle washing) at the local farm level in order to minimize the need for external initiatives
Step 4 (A) Implementation of Grey Water Solutions at HH and
Community Level
A) Current Status
Household and farm-level grey water (mixed with other waste) being disposed off in local water bodies, open land, leading to high-levels of environmental and health hazards.
Low-levels of grey water being treated at the household or community level
An absence of well-structured community and village level grey water management projects such as community level wet lands, small bore sewers, waste stabilization ponds, constructed wetlands, Anaerobic Baffled Reactors (ABRs)
Lack of technical know-how and a consistent set of in-situ technologies for grey water management at both the household and farm-level
B) Key Challenges
Challenging to demonstrate to households and farms the value in managing grey water from an economic, environmental, and health perspective
Existing options for in-situ disposal might require high-levels of effort and may not be cost effective
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Low “value-density” in grey water and hence low business viability of sustained grey water management services from a pure value recovery / markets perspective
District administrators can use a three-pronged approach to have their district adopting in-situ grey water management at scale. As a general principle, in-situ low-maintenance technologies should be encouraged. The three steps involved in this process are:
1) Establish Pilot Models and Showcase These Innovating Households level
technologies.
Based on the favorable conditions as mentioned in the above matrix for house hold and community based technology, district administrators should help set-up model grey water soak pits, Magic pits, kitchen gardens, and community wet lands at House hold and community level.
Dairies, animal farms, gaushalas, rural schools, religious institutions, etc. generate consistently large quantities of grey water that can be feasibly treated on-site (or at proximate treatment ponds) due to availability of space and can successfully adopt in-situ technologies.
Masons should be trained district wide to control quality of construction and ensure functionality of the system.
Use of Nhani Trap /P-Trap, which acts as filter media increases working life period of pit technologies.
Nhani/P trap, filters heavy solid particles and avoids clogging of filter media used in house-hold technology.
Similar to Nhani/P trap, community soak/leach pit should be provided with primary and secondary screening medium to separate out heavy solid particle from grey water
Must Know for House Hold and Community Level Technology!
2) District-Wide Communication & Technical Support
Once the training and communication collateral from the pilot sites is ready, District administrators should launch a district wide communication program to enlist different GPs in this program. For this the following sequence of activities can be planned
Training and planning workshops with GP officials. Administrators should call GP officials to the district headquarter for day-long grey water training and planning workshops. Each workshop should have not more than 30-40 GPs to ensure high quality interaction and absorption of training materials
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In this training workshop, high-level GP-level grey water management plans should be made (which will have other components as well) that the GPs should then be encouraged to fold into their GPDPs.
The training workshop should also include depth training of the GP-level SLRM Resource Person who would then be responsible for helping the GP implement these plans at scale.
After the training workshop, the District Administration should dedicate technical experts who will follow-up with all the participating GPs through the SLRM Resource Person providing technical assistance as needed.
3) Enforce a system of rewards and penalties
The District Administrator may enforce systems of rewards and recognition for households and farms who are delivering good results through in-situ options.
The District Administrator should strictly enforce a system of penalties to households and farms that do not carry out in-situ grey water management appropriately
GOAL: To facilitate the sustainable implementation of larger scale grey water management models at the community and village level in effective ways
4 (B) Implement Grey Water Management Models at Village
Level
GPs in the district where household or Community/decentralized systems are not feasible for treatment of grey water due to certain reasons such as inadequate space near houses due to densely located housing structure, hard strata in habitations, High water table areas and water logged conditions around houses, in such situations, it is necessary to opt for centralized systems for grey water management.
Solid waste management is must in the GPs where centralised treatment unit are being implemented. Absence of solid waste management in the region results in clogging of drains and makes it dysfunctional
Centralised treatment units should only be approved if there is high quantity grey water is generated from a village/GP
Favourable sloping conditions are necessary for transportation of greywater from source of generation to point of treatment.
District Administrators should strongly advocate for household-level separation of grey and black water and on site treatment of grey water through simple household level technology.
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1. Mobilize Informal, Formal, & Community-Based Project Participation.
District administrators should think of a three-pronged approach to setting up
community level grey water management projects
Earmark “zones” for grey water management and establish planning processes that balance efficiency and economic viability for service providers.
Villages and GPs could be organized into micro-zones based on natural slope for the development of grey water projects in ways that optimize collection efficiency and also financial viability for the project.
The district administration should model this based on population and water volume estimates
Based on this zoning, the district should develop standard operating procedures for grey water management from communities, villages, and bulk producers of grey water.
2. Develop a network of local grey water management service providers &
entrepreneurs
Service providers can be organized in the following ways:
Enterprising individuals meeting some minimum qualifications can be identified, similar to the ‘Surya Mitra’ scheme
Organize local FPOs and cooperatives and educate them on the economic opportunity linked to grey water management. Receive proposals from private operators and appoint the winning operators as service providers within specific zones
Carrying out training programs and access to finance facilitation for these operators to set up and running projects such as village wet lands, pond systems. Some of these operators could be individuals offered a small stipend.
Provide support to these operators through regular training programs
Facilitate User Participation and Standardized Fee Collection
Set standardized monthly user fees for the management of household grey water as well as grey water from bulk producers (such as cattle sheds).
Carry out sustained IEC to build awareness around the benefits from these services and the standardized rate card.
GOAL: To implement a rigorous system of measuring activities, outputs, and outcomes for grey water waste management in districts in order to carry out suitable course correction as needed.
Step 5: Implement Robust Monitoring & Evaluation
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A) Current Status
Lack of rigorous baseline data on GP-wise grey water levels, infrastructure availability, networks of service providers to run treatment processes.
B) Key Challenges
Reporting capabilities at the GP-Level
C) Monitoring Approach & Methods
District administrators should adopt a three-pronged approach to monitoring grey water waste management processes and outcomes at the GP level.
Deploy the measurement framework as specified and identify key metrics relevant to the district
Develop a data collection plan that will include a combination of self-reported statistics by the service providers, GP officials, crowdsourced data reported by end users, community meetings, spot checks by officials across the value chain of Grey water management
Develop a periodic system of follow-ups with service providers and GPs in case indicators fall outside the acceptable limits
Enforce high-quality waste management through a system of rewards and penalties for GPs who perform well. For this, district administrators can adopt some of the principles behind programs such as the Nirmal Gram Puraskar.
Carrying out quarterly reviews with the heads of the GPs and service providers to benchmark progress against the baseline VSI.
5.2 Guiding Principles
Given the challenges and key policy gaps that exist in rural grey water management, States should adopt policies that lead to the creation of a sustainable grey water ecosystem across the value chain. While specific policy interventions might vary depending on the context within the State, these key design principles should be generally applied
Develop grey water management projects at all three levels within rural India
- household-level, community-level, and the village-level: Effective grey water management requires households to manage grey water solutions (such as soak pits) at the household level, community level solutions such as well functioning drains connecting to different kinds of treatment solutions, and even village level drain network and treatment ponds.States & Districts should adopt a balanced approach that includes each of these three solutions.
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Invest substantially in IEC, behaviour change, capacity building, and convening to co-
create solutions: Grey water management, as compared to FSM or Plastics management, relies less on capital investments and infrastructure, and more on behaviour change and routines practiced by households and communities. Adequate awareness and behaviour change is an absolute must for success.
Identify viable business models that rely on innovative financing on the one-hand
and sale of by-products on the other: There are several examples where GPs have implemented grey water management solutions, such as village level ponds for grey water treatment, based on shared funding from the State Finance commission and village contributions. Projects have also involved the sale of treated grey water for partial cost recovery. Such business models should be actively promoted.
Operations & maintenance should be adequately emphasized:
Rely on convergent financing: Several pools of funds exist that can be leveraged for investment in grey water programs – MNREGA, MPLAD, SBM, SFC grants. They should also be used in convergent ways.
Invest in robust monitoring & evaluation: Grey water management, unlike asset-heavy themes such as toilet construction, is harder to measure well. Adequate attention must be given to defining performance metrics that get measured at different levels in an ongoing fashion.
5.3 Guidelines for State
Keeping these guiding principles in mind, State Mission Directors should adopt the following seven components in their planning:
Preparatory Phase
Develop the state-level strategy document for grey water management: This document
should define the goals for grey water management for the State and its districts and specify
roles and responsibilities for the PRIs based on PR provisions in Acts.
Develop and launch an incentive scheme for taking villages/ GPs up the ladder of
cleanliness: State Mission Directors should develop an incentive scheme that links GP-level
progress on the grey water ladder of cleanliness to different financial incentives provided for
within the SBM and other allied programs. These incentives can range from development
grants, preferred consideration for infrastructural investment projects, and other similar
programs.
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Develop and institutionalize an Awards Scheme for the State: SBM Mission Directors
should create a rewards and recognition program that rewards exemplary contribution and
achievement by various District and GP level stakeholders in moving towards improved grey
water management outcomes.
Appoint and operationalize State-level Advisory Committee for grey water
management: The SBM Director should appoint a solid and liquid resource management
committee at the State-level comprising of grey water management experts with appropriate
backgrounds.
Design and roll-out an effective IEC and media campaign focused on grey water: The
SBM Mission Director should work with the Advisory Committee, specialist media agencies,
and local NGOs to develop and deploy an effective media campaign that communicates the
benefits of appropriate grey water management, drives behaviour change in terms of grey
water management at the household level, community level, and the village level. Such
campaigns should focus on different technical options (soak pits, Constructed wet land,
Stabilization pond ponds etc) and their relative advantages and appropriate ways in which
to deploy them. IEC should also focus on the importance of deploying effective operating
and contractual and financing models to deploy these solutions at scale within Districts and
GPs. Key local influencers should be identified to be able to affect large-scale behaviour
change. Behaviours such as household level disposal of grey water for things such as kitchen
gardens, proper maintenance of village level drains and pipes, maintenance of treatment
ponds.
Enter into appropriate capacity development and implementation partnerships: The
Mission Director should foster partnerships with a range of PRI institutions and individuals
such as SHGs, Swachhagrahis, and Engineers, BDOs(SIRD, KRCs) to build capacity and
ensure knowledge exchange. This should be based on a robust certification system for grey
water management trainings.
Financial Convergence Plan forGrey Water Projects: Mission Directors should also prepare
a convergent financing plan for large grey water management projects especially ones at the
village level.
Implementation Phase
Triggering roll out plan in villages: Mission Directors should work with concerned
teams and develop a detailed rollout plan covering different Districts and GPs in the State.
Appropriate technical assistance to develop the rollout plan, consultations with local
stakeholders, PRIs, NGOs may be carried out as needed.
Taking-up grey water project works: Mission Directors should work with their teams,
selected agencies, GPs, private organizations to plan and implement a set of carefully
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selected grey water projects such as tanks, village level drain systems, treated water
purchase contracts.
Monitoring and Evaluation: Mission Directors should also develop a carefully considered
monitoring and evaluation plan that identifies activity, output, outcome metrics related
to overall goals and impact parameters. SBM state directors should assign monitoring
responsibilities to districts and act as third-party observers and ensure that every step in
the grey water value chain (from household segregation to community-level disposal) is
functioning optimally. MIS systems focused on SLWM can be deployed as appropriate.
Enforce rewards and penalties As stated earlier, Mission Directors, should enforce
penalties with Districts where key process parameters, such as segregation at source are
below the agreed thresholds. Conversely, high-performing districts and GPs should be
recognized and rewarded appropriately.
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GREY WATER STRATEGY6
It is often seen that a long strategy document tends to be pedantic and does not lend itself to implementation. Therefore, a brief yet implementable strategy has been delineated below:
State level strategy
1. Set up a State level Task Force (STF) which will be responsible for the whole Grey water campaign.
2. Divide State into zones based on – high water table / low water table, rocky terrain, population density (high and low). State could take up the programme in phases. It could consist of villages with PWS and / or high density villages with suitable soil, terrain and ground water levels.
3. Have a zone-wise strategy for choosing the right technology. Issue a State level advisory regarding the same.
4. Refer to technical section of the Grey Water Manual to choose the right technology mix for that zone.
5. Diagnostic Methods:
The Survey template is attached as Annexure B. The Survey template may be issued to districts for completing village level survey and for reporting on proposed action plan giving both physical and financial plan.
6. State should look at its Panchayati Raj Act for setting up a system of fines and penalties. A brief writ-up on roles and responsibilities of Gram Panchayat across the country is attached as Annexure C. SBM Mission Director to ensure Rural Development / Panchayati Raj Department issues necessary directions to the GPs to fulfill their obligations with regard to sanitation as per the Panchayati Raj Act provisions.
7. Develop a network of local grey water management service providers and entrepreneurs. Issue a RFP and empanel private operators for the State Zone-wise. Districts can take their help where community treatment plants are the only option. Support the private operators by linking them to Credit support programmes like Mudra and other MSME support programmes and also put in place a regulatory framework.
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8. Prepare an IEC strategy (Annexure D):
State Task Force should create a whole set of IEC materials in the local languages to be used throughout the State.
9. Strategy for doing capacity building of Sarpanches / Pradhans and Gram Sachivs on preparing and incorporating grey water action plans in GPDP.
10. Issuing administrative orders for constituting block level teams to prepare district grey water action plans.
11. Mason training on Grey Water technologies in SIRDs or in KRCs.
State level task force to make the training modules available and provide funding for Mason training.
12. STF – To create a system of assessment and awards by doing district visits.
State level Task Force to appraise all district action plans and rank districts on performance on the planning / preparation / implementation aspects. Use tools given in Annexure 4.
13. State level assessment of works and declaration of GP awards by Aug 15th.
District
1. District to prepare block-wise plans based on the terrain / population and water table profile of the village.
2. Districts to take up pilot villages and set up demonstration models.
3. Organize block-wise training programme for preparing a block-wise action plan. May use IEC budgets for setting demonstration models in select GPs.
4. DC/CEO/CDO to issue a time bound programme with clear responsibility matrix for preparation of grey water action plan.
– Preparation of village wise visit plan wherein triggering and other IEC activities will be taken up.
– Making an action plan – (choosing type and no. of units) specific to the village. For eg. Whether individual Soakpits should be taken or community based soak pit. Total nos. required, etc. See Anneuxre 1.
– Funding plan preparation
District to collate all plans at block level and match funds (MNERGA / DMFT / SBM) from various available sources.
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5. District to prepare DPRs and take necessary
– Administrative and technical sanctions.
6. Setting up Monitoring and Evaluation teams.
Village
(a) Take a Gram Sabha and decide on inclusion of Grey water in GPDP
(b) A village level survey to be fixed wherein villages will be motivated through triggering. Triggering can be done through a suitable mix of IEC tools.
(c) Village level action plan to be framed
– No. of units with their location (based on land availability). See Annexure 1.
(d) The funds will be provided by GP from funds available with it under 14th Finance Commission or any other and handover the plan to Block level team.
(e) Block level teams will finalize the same and get the DPRs prepared.
(f) Implementation will start once district gives approval.
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The technical options recommended are:
1. Soak pits
2. Leach pits
3. Magic pits
4. Kitchen garden
5. Community soak pit
6. Community leach pit
7. Community wet land
8. Community kitchen garden
9. Waste Stabilisation Ponds
10. Duck Weed Pond System
11. Constructed Wetland
12. Soil Bio Technology (SBT)
13. Phytorid Technology
14. Anaerobic Baffled Reactor (ABR)
1. Soak pits
A soak pit, also known as a soakaway or leach pit, is a covered, porous-walled chamber that allows water to slowly soak into the ground. A soak pit can also be used to dispose of the effluent from a septic tank. Pre-settled effluent from a Collection and Storage/Treatment or (Semi-) Centralized Treatment technology is discharged to the underground chamber from which it infiltrates into the surrounding soil.
As greywater percolates through the soil from the soak pit, small particles are filtered out by
ANNEXURE A: Compendium on Technologies for Different levels of Grey Water Management Interventions
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the soil matrix and organics are digested by microorganisms. Thus, soak pits are best suited for soil with good absorptive properties; clay, hard packed or rocky soil is not appropriate. However soakpits are easy and relatively quick to construct; and can be used on plain areas. Performance of soakpit depends on the permeability of soil. Pores of soil may get clogged with time and this can reduce the percolation capacity of a particular soak pit. Seasonal variations in the water table can also affect the performance greatly and a soak pit performs better in dry season.
Merits
Low cost and easy to construct
Dry environment: the entire wastewater from a household is absorbed by this underground structure. This results in dry premises;
Freedom from the mosquito nuisance; and Odour-free environment;
No drains required;
Recharge of ground water: the wastewater enters the natural ecosystem and finally reaches to the ground water stream thus recharging the ground water source; and
O&M costs are low and borne by individual.
Demerits
• One of the demerits is possibility of ground water contamination if grey water is contaminated with faecal substance especially in the areas with high groundwater table.
Soak pit
Dug out pit filled with stones or preferably over burnt bricks. The large numbers of stones increase the surface area over which biological and chemical action takes place.
Top of Lining Plastered in cement mortar 1:6
R.C.C. Slab 1:2:4Gound Level
Solid brick work in cement mortar 1:6
Brick work in cement mortar 1:6 with honeycombing in alternate brick courses upto invert level of pipe or drain
25mm dia A.C. or P.V.C nonpressure pipe with junction chamber
Base of pit
225225
75
7530
0H
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Magic Pit – Modified Soak pit
A Magic pit, is a covered, porous-walled chamber that allows water to slowly soak into the ground. Pre-settled effluent from a collection tank is discharged to the underground chamber.
2. Leach Pit
This is the simplest and cheapest technology for treatment of household grey water, requiring minimum space. Operation and Maintenance (O&M) of this system is also minimal and easy.
Description
This is a brick-lined pit constructed in the courtyard of a house at a convenient place. The grey water from the house (kitchen wastewater, bathing water and washing water.) should be directed to this pit. It is advisable to pass the water through a nhani trap or P trap to avoid entry of mosquitoes and exit of foul odour. A silt chamber can be an added advantage to avoid any solids entering into the pit. The pit is suitably covered with flag stones or Reinforced Concrete Cement (RCC) cover of required dimensions.
Merits
Dry environment: the entire wastewater from a household is absorbed by this underground structure. This results in dry premises;
Freedom from the mosquito nuisance;
Odour-free environment;
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No drains required;
Recharge of ground water: the wastewater enters the natural ecosystem and finally reaches to the ground water stream thus recharging the ground water source; and
O&M costs are negligible and borne by the individual.
Demerits
Site Selection
The pit should be located 3 feet (ft) away from the house wall;
It should be 10 ft away from any ground water source; and
It should be as near as possible from the source of wastewater (to save on the pipeline).
Design Considerations
Shape: preferably circular (cylindrical) to make it low cost yet durable and maximise volume;
Construction: honeycomb masonry in alternate layers to facilitate seepage of water;
Bottom of the pit: not to be cemented or concreted to facilitate seepage of water;
Inlet pipe: 63 to 75 millimetre (mm) diameter Polyvinyl Chloride (PVC) or Soil, Waste and Rain (SWR) pipe: to be connected to the pit keeping 200 mm freeboard;
Volume: effective volume to be kept: 21 cubic feet (cft)/0.78 cubic metre (m3). The volume can be increased if the wastewater generation is higher; and
Alternate construction material: the pit can be conveniently constructed using prefab cement rings with holes and an RCC or ferrocement cover.
Step-by-step Construction
1. Excavation
Dig a pit with 1.5 metre (m) diameter and 1.25 m depth
2. Construction
Construct the pit in single brick with honeycombing in alternate layers. Honeycombing should be through 6 to 8 holes of 40 mm each. Brick masonry is to be done in 1:6 cement mortar
3. Connect the pipe at a height of 1 m from the bottom. The pipe should protrude 100 mm inside the pit.
4. Cover: 40 mm thick RCC cover cast in two halves/ferrocement slabs/flag stone
5. Cover to be properly sealed to avoid vector entry
6. Cover to be covered with soil layer of about 200 mm
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Alternate Construction Material
The pit can be constructed using prefab cement rings. Four rings of 300 mm height with honeycombing can be placed one over another and covered with RCC/ferrocement slab/flag stone.
Connection with Household Wastewater
1. As described in previous paragraphs, the household wastewater must pass through a nhani trap or a P trap to avoid vector entry and odour nuisance. The nhani trap should also be covered with a suitable screen to screen out solids from the wastewater.
2. If excess amount of impurities such as ash/dirt are expected, a silt chamber see figure ) at a suitable point is advisable.
3. The pipe from the nhani trap/silt chamber should directly go to the leach pit.
4. It is always advisable to lay the pipe underground and from the periphery of the courtyard to avoid accidental damage.
Operation and Maintenance
A) Cleaning of nhani trap and silt chamber should be done weekly/fortnightly or as required; and
B) De-sludging of the leach pit should be done once in two years. If a grease trap is provided and is periodically cleaned then the pit does not require any de-sludging for five to six years or more.
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Figure 1: Domestic leach pit with silt chamber in brick masonry
Figure 2: Domestic leach pit with silt chamber in precast cement rings
Domestic Leach Pit with Silt Chamber(For a single household capacity 250-300 lit per day)
BB masonry
ESTIMATE
Sr. No.
Particulars Quantity Rate Total Cost
Material Required
1 Bricks 225 Nos2 Sand 0.18 cum3 Cement 1/3 bag4 Stone Metal 0.02 cum5 PVC Pipe
63 mm dia0.5 m (or as required)
6 Pit Covers 1200x600 mm
2 Nos
7 Cover on chamber 900x450 mm
1 Nos
Labour required
8 Exacavation 1/2 man day9 Mason 1/2 man day10 Labour
(construction1 man day
Total
Note: Fill up the local rates 'Rate' in column and calculate the total cost
Domestic Leach Pit with Silt Chamber
Precast cement rings(For a single household capacity 250-300 lit per day)
ESTIMATE
Sr. No.
Particulars Quantity Rate Total Cost
Material Required
1 Bricks 50 Nos2 Cement rings
1000 diax300 mm4 Nos
3 Sand 0.02 cum4 Cement 3 Gamlas5 PVC Pipe
63 mm dia1.5 m (or as required)
6 Pit Covers 1200x600 mm
2 Nos
7 Cover on chamber 900x450 mm
1 Nos
Labour required
8 Exacavation 1/2 man day9 Mason 1/2 man day10 Labour
(construction1/2 man day
Total
Note: Fill up the local rates 'Rate' in column and calculate the total cost
Grey Water Management in Rural India
41
3. Kitchen Garden
This is the easiest way of reusing wastewater at household level. If grey waste water is purified to some extent, it can very well be used for growing vegetables/flowers/fruits for domestic purposes.
Merits
This is the most environment-friendly way of handling wastewater.
It is the utilisation of waste and can save a large quantity of fresh water which otherwise would have been used for the same garden.
The nutrients contained in the wastewater also provide nourishment to the growing plants.
Requirements
1. Adequate space in the backyard for growing plants
2. Willingness of the householders to grow vegetation in the backyard
Design Considerations (Refer Figure 3)
The design of a kitchen garden will differ with every house. Careful planning is essential. The following factors should be taken into consideration while planning for a kitchen garden:
1. Space available for garden
2. Quantity of grey water available for gardening
3. Plant species intended to be grown
It should be seen that the grey water generated at the household level is fully utilised in the area available.
If the area is limited, grey wastewater that can support plants in the available area should be used in the garden and the rest should be suitably diverted/treated into other systems such as a leach pit.
Description
As described in previous paragraphs, the household wastewater must pass through a nhani trap or a P trap to remove impurities. The nhani trap should also be covered with a suitable screen to screen out solids from the wastewater. Additional provision of a silt chamber is also recommended to remove organic and inert matter. This will ensure clearer water in the kitchen garden and will stop the odour nuisance and vector breeding.
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The wastewater passed through nhani trap and silt chamber can either be directly used in the kitchen garden or it can be first stored in a suitable storage tank and used as per the need of the plants.
Operation and Maintenance
A) Cleaning of the nhani trap and silt chamber should be done weekly/fortnightly or as required;
B) Deposition of inert matter/organic matter/salts on the soil surface should be removed after harvesting of crops;
C) In the rainy season, grey water is not required by the garden. It should be diverted/treated in other systems such as a leach pit to avoid stagnation of water and vector breeding; and
D) Precaution should also be taken to avoid use of strong detergents and chemicals which may have a residual effect on the plants grown. If such chemicals are being used, the grey water may not be used to grow tubers (potato, onion, etc.).
Figure 3: Schematic of grey water reuse in kitchen garden
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4. Technologies for Grey Water Management at
Community Level (Semi-centralised Level)
A) Community Leach Pit for a Group of Houses
In situations where the houses are densely located and there is no space for an individual leach pit or kitchen garden, or the soil structure does not favour an individual leach pit in every house (rocky or impermeable strata), a community leach pit for a group of houses may be a desirable option.
Description
This is a brick-lined pit constructed at a convenient place for a group of houses. The number of houses to be connected should be calculated based on the grey water discharged from each house. Grey water from the houses should be carried to this pit.
Essential Components of the System
1. Nhani trap or P trap at every house
2. Primary silt chamber at every house
3. Pipeline (3 to 4 inch diameter PVC or SWR pipe) laid preferably underground but at a shallower depth
4. Secondary silt chamber near the leach pit
5. A leach pit of specific dimensions
Merits
Dry environment: the entire wastewater from a household is absorbed by this underground structure. This results in dry premises and streets;
Freedom from the mosquito nuisance;
Odour-free environment;
Recharge of ground water: the wastewater enters the natural ecosystem and finally reaches to the ground water stream thus recharging the ground water source;
A low-cost option compared to a drain + treatment unit; and
O&M costs comparatively much lower than the drain + treatment system.
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Site Selection
The pit should be located at a place where the natural gradient can be obtained for grey water flow;
It should be 5 m away from any ground water source; and
It should be as near as possible from the source of wastewater (to save on the pipeline).
Design Considerations (Refer Figure)
Shape: preferably circular (cylindrical) to make it low cost yet durable and maximise volume;
Construction: honeycomb masonry in alternate layers to facilitate seepage of water;
Bottom of the pit: not to be cemented or concreted also to facilitate seepage of water;
Inlet pipe: 75 to 100 mm diameter PVC or SWR pipe to be connected to the pit keeping 300 mm freeboard; and
Volume: effective volume to be kept equivalent to the daily discharge of grey water from the connected houses.
Step-by-step Construction (Refer Figure)
1. Excavation: dig a pit of the required dimensions
2. Construction: construct the pit with 225 mm thick brick work with honeycombing in alternate layers. Brick masonry to be done in 1:8 cement mortar
3. Piping: connect the pipe at a height keeping 300 mm freeboard. The pipe should protrude 100 mm inside the pit
4. Corbelling: the diameter of community leach pit is always larger. Hence the top portion should have corbelling to reduce the diameter of opening at the top to about 1 m (please refer figure 11)
5. Cover: 50 mm thick RCC cover cast in two halves/ferrocement slabs/flag stone
6. The cover to be properly sealed to avoid vector entry
7. The cover to be covered with a soil layer of about 300 mm
Connection with Household Wastewater
As described in previous paragraphs, the household wastewater must pass through a nhani trap or a P trap to avoid vector entry and odour nuisance. The nhani trap should also be covered with a suitable screen to screen out solids from the wastewater.
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1. If an excess amount of impurities such as ash/dirt are expected, a silt chamber (see Figure 4) at a suitable point is advisable
2. The pipe from the nhani trap/silt chamber should directly go to the leach pit
3. It is always advisable to lay the pipe underground and from the periphery of the courtyard to avoid accidental damage
Operation and Maintenance
A) Cleaning of the nhani trap and silt chamber should be done weekly/fortnightly or as found essential; and
B) De-sludging of the leach pit should be done once in two years. If the silt chamber is provided and is periodically cleaned then the pit does not require any de-sludging for five to six years or more.
Figure 4: Community leach pit with silt chamber
Domestic Leach Pit with Silt Chamber(For a group of 10-15 households / 3000 lit per day)
Also useful for community water points
ESTIMATE
Sr. No.
Particulars Quantity Rate Total Cost
Material Required
1 Bricks 1000 Nos2 Sand 0.18 cum3 Cement 1/4 bag4 Stone Metal 0.08 cum5 PVC Pipe
63 mm dia3 m (or as required)
6 Pit Covers 1200x600 mm
2 Nos
7 Cover on chamber 1000x500 mm
1 Nos
Labour required
8 Exacavation 1 man day9 Mason 2 man day10 Labour
(construction4 man day
Total
Note: Fill up the local rates 'Rate' in column and calculate the total cost
Grey Water Management in Rural India
46
B) Management of Grey Water from Public Water Points
Some GPs have provision of public water supply in the form of hand pumps, stand posts or wells. At all such places, a large quantity of water is wasted. This also needs to be managed properly, else the water from such sources flows onto roads and open spaces and causes inconvenience. This can be managed like kitchen gardens at home, wastewater from community water sources can very well be utilised in community plantations and orchards.
Requirements
1. Adequate space near the water point; if at all such space is not available in the vicinity, this water can be conveyed to the required distance through a pipeline; and
2. Some arrangement can be made at the GP level for management of the system. This task can be assigned either to Self Help Groups (SHGs), youth groups or even to some private entrepreneurs.
Design Considerations (refer figure for details)
The design of a plantation will differ with every water point. Careful planning is essential. The following factors should be taken into consideration while planning for a plantation.
1. Space available for plantation
2. Quantity of grey water available for irrigation
3. Plant species intended to be grown
Suggested Usage
1. Vegetable garden for commercial purpose
2. Orchards (fruit trees) for commercial purpose
3. Existing park/garden in the village
4. Roadside trees/other vegetation
Description
The wastewater generated at public water points is generally spilled and does not contain impurities such as organic matter, ash or other chemicals. But it invariably contains dirt and mud. Hence, it must be passed through a silt chamber (refer figure) so that solids-free water is available for end use. The silt chamber should be constructed near the water point and the solids-free water should then be carried through pipes to the plantation site. This will avoid clogging of pipes with dirty water.
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Operation and Maintenance
A) Cleaning of the silt chamber should be done weekly/fortnightly or as required;
B) Deposition of inert matter/organic matter/salts on the soil surface should be removed after harvesting of crops; and
C) In the rainy season, grey water is not required by the garden. It should be diverted to some other system to avoid stagnation and vector breeding.
2. Large Leach Pit
If it is not possible to make use of wastewater from community water points in a garden/plantation, it is advisable to construct a large leach pit and soak the wastewater in it.
Description
This is a brick-lined pit constructed at a convenient place near the water point. The design and other parameters of this leach pit will be the same as that of the community leach pit. A silt chamber of a suitable size should be constructed near the water point and all the spilled water should be directed to this chamber. From this chamber, it should be taken to the leach pit through a pipeline.
Essential Components of the System
1. A well cemented platform around the water point (hand pump, stand post or well) so that all the spilled water will conveniently be directed at one point.
2. A silt chamber near the water point (see figures)
3. A pipeline (100 mm diameter PVC or SWR pipe) from the silt chamber to the leach pit laid preferably underground but at a shallower depth
4. A leach pit of specific dimensions
Significance of a Large Size Leach Pit
Dry environment: spilled water from the water point is absorbed by this underground structure. The surrounding premises remain dry and clean;
Freedom from the mosquito nuisance;
Odour-free environment;
Recharge of ground water: the wastewater enters the natural ecosystem and finally reaches to the ground water stream thus recharging the ground water source;
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48
A low-cost option compared to a drain + treatment unit;
O&M costs comparatively much lower than for the drain + treatment system.
Site Selection
The pit should be located at a place where the natural gradient can be obtained for grey water flow; and
It should be a minimum of 5 m away from the water source.
Design Considerations (Refer Figure 5)
Shape: preferably circular (cylindrical) to make it low cost yet durable;
Construction: honeycomb masonry in alternate layers to facilitate seepage of water;
Bottom of the pit: not to be cemented or concreted also to facilitate seepage of water;
Inlet pipe: 75 to 100 mm diameter PVC or SWR pipe, to be connected to the pit keeping 300 mm freeboard; and
Volume: effective volume to be kept equivalent to the water discharge per day from the water point.
Step-by-step Construction (Refer Figure)
1. Excavation: dig a pit with the required dimensions
2. Construction: construct the pit with 225 mm thick brick work with honeycombing in alternate layers. Brick masonry to be done in 1:8 cement mortar
3. Piping: connect the pipe at a height keeping 300 mm freeboard. The pipe should protrude 100 mm inside the pit
4. Corbelling: the diameter of the community leach pit is always larger. Hence, the top portion should have corbelling to reduce the diameter of the opening at the top to about 1 m (refer figure 11)
5. Cover: 50 mm thick RCC cover cast in two halves/ferrocement slabs/flag stone
6. The cover to be properly sealed to avoid vector entry
7. The cover to be covered with a soil layer of about 300 mm
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Connection with the Water Point
1. The final outlet from the platform around the water point should be connected to the silt chamber by a 100 mm PVC/SWR pipe
2. The silt chamber should be connected to the leach pit by a 100 mm PVC/SWR pipe of a suitable length
Operation and Maintenance
A) Cleaning of the silt chamber should be done weekly/fortnightly or as found essential; and
B) De-sludging of the leach pit should be done once in a year.
5. Technologies for Grey Water Management at the
Community Level (Centralised Level)
There are GPs where decentralised or semi-centralised systems are not feasible for the following reasons:
A. No space near houses due to densely located housing structure;
B. Hard strata in habitations;
C. High water table areas; and
D. Water logged conditions around houses.
In such situations, it is necessary to opt for centralised systems for grey water management. A centralised grey water management system has the following essential components:
1. An improvised bathing cubicle or similar structure at the household with a nhani trap/P trap
2. A silt chamber at thee household
3. Transport of grey water from individual households to the final treatment unit with intermediate silt chambers
4. A final treatment unit
Transport of Grey Water
It is advisable to convey grey water from individual houses to the treatment unit through a pipeline.
The advantages of a pipeline over a conventional drain include:
a. Minimum resistance;
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50
b. Ease in implementation – laying of a pipeline is easier than constructing a drain;.
c. No clogging by indiscriminate dumping of garbage en route;
d. Maintenance easier than that of a drain; and
e. More economical than a drain.
Specifications of the Pipeline
A) Laterals: from houses to the main pipeline – 75 to 100 mm diameter PVC or SWR pipe;
B) Mains: up to the treatment unit – 150 mm diameter PVC pipe;
C) The pipeline to be laid at a shallower depth. If old drains exist, pipelines can be laid through these drains and the drains closed. It is advisable to have a contour survey of the village and lay the pipeline accordingly. This will ensure a proper flow of grey water to the treatment unit and the cost of the pipeline will also reduce;
D) From the silt chamber at the household. (Refer Figures); and
E) Intercepting chambers on the main pipelines (Refer Figures ) should be located at all junctions, at turns, curves and also on the straight pipeline at every 75 to 100 m depending upon the ground situations.
Final Treatment Unit
This is an important component of a centralised system. This can be of various types such as a grey water stabilisation pond or a reed bed system or an anaerobic baffled reactor, etc. The choice of the technology will depend upon: 1) quantity of grey water to be treated; 2) distance from habitation to the treatment unit; 3) affordability; and 4) land and human resources available with the GP.
(A) Grey Water Stabilisation Pond/Waste
Stabilization Pond
Description
This is a series of basins or ponds excavated at a suitable site away from the human habitation where grey water is treated. The treatment is almost natural which involves:
1. Stabilisation of water which results in sedimentation and separation of impurities
2. Degradation process involving bacteria, algae, sunlight and oxygen which reduces the toxicity of grey water and increases its usability
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Essential Components of the System
The system has three basic units called ponds, placed in a series and characterised by their function such as:
1. Anaerobic pond – one number
2. Facultative pond – one number
3. Aerobic pond or maturation pond – one or more in number depending upon the impurities in the grey water
Design Considerations (Refer Figure)
1. Anaerobic Pond
This is the first in the series. It receives the raw grey water along with physical impurities from the collection system; hence, it also has to act as settling pond.
Working Principle:
1) Separation of solids and inert matter and settling at the bottom
2) Anaerobic digestion of organic matter in the settled solids
Hydraulic Retention Time (HRT): one to two days
Dimensions: depth -2.5 to 3 m, length and width or the diameter to be adjusted accordingly to obtain the necessary volume to maintain the required HRT
B) Facultative Pond
This is the second pond in the series. It receives partially clarified grey water from the anaerobic pond. In this pond, aerobic as well as anaerobic digestion takes place. Hence this is called facultative pond
Working Principle:
1) Aerobic digestion takes place at the upper layer
2) Anaerobic digestion takes place at the lower layers
HRT: three to five days
Dimensions: to facilitate the maximum aeration depth of this pond, it is shallower and the surface area is increased
Depth: 1.2 to 1.5 m, length and width or the diameter to be adjusted accordingly to obtain the necessary volume to maintain the required HRT
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C) Aerobic Pond/Maturation Pond
This is the third pond in the series. It receives stabilised water from the facultative pond. In this pond, mainly aerobic digestion takes place which helps in reducing the toxicity of the grey water.
Working Principle:
1) Aerobic digestion takes place at the upper layer
2) Oxidation also takes place which further helps in reducing toxicity
HRT: three to five days
Dimensions: to facilitate the maximum aeration depth of this pond, its depth is also kept at a minimum and the surface area is increased
Depth: 1.2 to 1.5 m, length and width to be adjusted accordingly to obtain the necessary volume to maintain the required HRT
If the grey wastewater is highly polluted, then the number of maturation ponds can be increased to two or three.
Other Parameters
Shape:
• Anaerobic pond: this can be circular or rectangular in shape to facilitate better sedimentation. It can be brick-lined for better stability
• Facultative and maturation ponds: these should have a trapezoidal shape to facilitate maximum aeration. This shape can also be achieved by proper excavation and earth work. These ponds may or may not be lined depending upon the soil structure. Wherever possible, rubble pitching also helps to achieve stability;
Size, dimensions and inter-pond connections: please refer figure );
In facultative and maturation ponds, the width to length ratio should be preferably 1: 3; and
Primary screening: bar screens can be installed before the anaerobic pond to screen out the solids (debris/inert matter/plastic, etc.) carried with the grey water.
End Use of the Treated Water
The treated water from the stabilisation pond can be used for agriculture or pisiculture depending upon the purity of water. The various parameters for such reuse are (CPCB, 2015):
BOD – ≤10 milligram/litre (mg/l)
COD - ≤ 50 mg/l
Faecal coliform content (MPN/100 millilitre (ml)) ≤ 100
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Chlorination of Treated Water
At the end of the maturation pond, a pot chlorinator can be installed to achieve extra safe water for reuse. However, care should be taken to adjust and maintain the standard chlorination dosing.
Operation and Maintenance
A) Cleaning of intercepting chambers on the pipeline and bar screens before anaerobic ponds;
B) Maintenance of embankments of the ponds;
C) Periodical desludging of anaerobic pond and filter/screen, if any;
D) Removal of floating scum from all ponds;
E) Post-monsoon maintenance of the entire system; and
F) Periodical anti-mosquito spraying, as and when required.
Figure 5: Grey water stabilisation pond
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Table: Volume of Grey Water Stabilisation Pond for Different Sizes
Table 3: Dimensions of Grey Water Stabilisation Ponds for Different Capacities
Figure 14: Schematic of a Phytorid Bed
Grey water generation per day
Volume of Anaerobic Pond
Volume of Facultative Pond
Volume of Maturation Pond
15,000 30,000 75,000 75,000
30,000 60,000 1,50,000 1,50,000
60,000 1,20,000 3,00,000 3,00,000
90,000 1,80,000 4,50,000 4,50,000
Grey Water (per day)
Anaerobic Pond Facultative Pond Maturation Pond
Length (m)
Width (m)
Depth (m)
Length (m)
Width (m)
Depth (m)
Length (m)
Width (m)
Depth (m)
15,000 5 2.5 2.7 11.2 5.6 1.5 11.2 5.6 1.5
30,000 7.1 3.5 2.7 15.8 7.9 1.5 15.8 7.9 1.5
60,000 10 5 2.7 22.4 11.2 1.5 22.4 11.2 1.5
90,000 12.3 6.1 2.7 27.4 13.7 1.5 27.4 13.7 1.5
Note: Depth of all ponds includes a freeboard of 0.3 m.
(B) Reed Bed System/Phytorid SystemReed bed or phytorid systems rely on the ability of plants to purify the wastewater. The system entails solids capture to prevent carry over of solids and clogging of the reed/phytorid bed.
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Figure 6: Photographs of Wastewater Flows Through Phytorid System
The principles of phytorid system are:
i. Oxygen diffuses from the atmosphere to the wastewater
ii. Anaerobic treatment at the lower levels of the bed
iii. Nutrient and phosphorus uptake by the plants
The system is very effective in purifying wastewater as can be seen in the images in Figure 14.
Duckweed Pond Duckweed based wastewater treatment is potentially suitable for small scale application at rural level and for medium-sized facilities at community, (peri-) urban level. Duckweed is a group name belonging to botanical family Lamnaceae that consists of four genera namely - Spirodela, Lemna, Wolffia and Wolfiella; first 3 genera are commonly found in India. It is cosmopolitan and found everywhere in organic nutrients rich stagnant water. It has very high growth rate; at optimum nutrient environment it doubles within 2-3 days. It tolerates wide range of temperature - between 100-460C, depending upon the genera. Size of the plant is very small. Wolffiella is the smallest plant having pin head size, while Spirodella is the largest one, having its size of 2-3 cm only. The most important feature with this plant is that it contains up to 30% edible protein, vitamins A and C. It is a complete feed for certain species of fish like Grass carp, Silver carp, Common carp, Rehu and Mrigal. High yield of fish has a direct linkage with economic return and thus, employment avenue with the system.
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The system is being adopted in several developing countries (Sascha Iqbal, 1999). Since duckweed grow very fast in waste water, it uptakes nutrients from waste water very quickly and form green mat over water (Fig. 2.20). Thus, in addition to normal settling of waste water, there is bioaccumulation of nutrients in duckweed. Duckweed has the ability to bio accumulate upto 99% of the nutrients, dissolved solids and even heavy and toxic elements of wastewater up to certain extent. These are permanently removed from wastewater as plants are harvested. Hence, it reduces Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), suspended solids, bacterial and helminthic pathogens, some organic compounds, ions of potassium, nitrogen, phosphate and even heavy metals of wastewater to a level, quite safe for disposal.
Duckweed based pond system can be used to give further treatment to effluent from facultative pond to meet more stringent BOD and TSS regulation and can generate some financial returns from duckweed-fish cultivation. Some kind of pretreatment such as anaerobic pond/anaerobic baffled reactor and facultative pond are required for duckweed pond. Since duckweed is a free floating plant, it requires only bamboos or PVC cubicles (4m x5 m), to check drifting of duckweed to one end, along with wind.
Bamboos are more preferred as there is chance of theft of PVC articles in villages. Duckweed can be found everywhere in stagnant water in villages. No other equipment are required for this treatment process.
Required size of the pond depends on quantity of waste water generated per day. For a half mld of waste water, one hectare of pond surface area (0.5 hac for duckweed and 0.5 for fish pond) is required. It is suitable for a village having population of 4000-5000. Size of the fish pond normally should be half of the treatment pond. However, additional larger size of the fish pond is more useful to have more economic return in terms of fish production. Duckweed forms a green mat over waste water, thus reduces the chance of mosquitoes to breed in waste water.
Since duckweed grows very fast, its regular harvesting is required. 25% of the area of duckweed pond should be harvested daily. It can be harvested manually through a simple net device attached with a bamboo. Freshly harvested duckweed is filled into a wicker work basket, where it remains for some time to allow some water drainage and pathogen removal by sunlight irradiation.
Advantages of duckweed based treatment of waste water
Duckweed grows rapidly and is capable of nutrient uptake under a wide range of environmental conditions. Compared to most other aquatic plants, it is less sensitive to low temperatures, high nutrient levels, pH fluctuations, pest, and diseases (Dinges 1982)
Duckweed and its associated microorganisms are capable of absorbing and disintegrating a number of toxic compounds (Landolt and Kandeler 1987).
Duckweed has been observed to efficiently absorb heavy metals (Landolt and Kandeler 1987). This characteristic may be detrimental if duckweed is used as feed.
When grown on nutrient-rich waters, duckweed has a high protein and a relatively low fibre content and is, thereby, suitable for use as high-quality feed supplement.
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Harvesting of duckweed plants from the water surface is easy.
A complete duckweed cover on the wastewater may efficiently prevent the growth of algae in the water body and result in a clear effluent of low TSS content.
The presence of a dense duckweed mat has been reported to decrease and control the development of mosquito and odour in a wastewater body.
There is economic return and employment avenue in term of pisciculture when duckweed is used as fish feed grown on domestic sewage.
Constructed WetlandsA horizontal flow constructed wetland (horizontal flow CW) is a planted filter bed for secondary or tertiary treatment of wastewater (e.g. grey water or black water). After primary treatment for solids removal in a UASB or Anaerobic baffled reactor, the wastewater is fed at the inlet zone and flows horizontally through the porous filter medium (sand or gravel) until it reaches the outlet zone. The water is treated by a combination of biological and physical processes. The effluent of a well-functioning constructed wetland can be used for irrigation and aquaculture or safely been discharged to receiving water bodies. Horizontal flow CW are relatively inexpensive to build where land is affordable and can be maintained by the local community as no high-tech spare parts, electrical energy or chemicals are required.
A horizontal subsurface flow constructed wetland is a large gravel and sand-filled channel that is planted with aquatic vegetation. As wastewater flows horizontally through the channel, the filter material filters out particles and microorganisms degrade organics. The water level in a Horizontal Subsurface Flow Constructed Wetland is maintained at 5 to 15 cm below the surface to ensure subsurface flow (Tilley, et al 2008). To avoid clogging of the wetland, pre-treatment is necessary. It has been established that a horizontal filter bed area of about 2 m2/PE is sufficient for the complete secondary and tertiary treatment of wastewater including the removal of pathogenic germs (Sonavane et.al 2008), (CPCB, 2008).
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With the available experience the following list of species can be given:
i. Phragmitesaustralis (reed)
ii. Phragmiteskarka (reed)
iii. Arundodonax (mediteranean reed)
iv. Typhalatifolia (cattail)
v. Typhaangustifolia (cattail)
vi. Juncus (bulrush)
The vegetation is a critical component for the successful operation of wetlands. For horizontal CW, in principle, all helophytes can be used, which are deep rooted and oxygenate the Rhizosphere through the roots. The most common maintenance activities are pulling out undesirable plant species such as willow tree saplings, removing dead vegetation and cleaning pipes. Other maintenance activities include replanting, fertilizing, cleaning/ brushing screens and pipes, and installation of barriers to exclude deer.
Selection of species for Constructed wetland
Soil Bio Technology (SBT)
This technology has been developed by IIT, Mumbai. SBT engages three fundamental process of Nature – Photosynthesis, respiration and mineral weathering. This is achieved by soil micro-organisms which are regulated by soil micro–organisms (geophagus earthworms). Primary and Secondary treatments are achieved in the SBT. The organic & inorganics in wastewater is consumed and converted into useful byproducts and simultaneously water of desirable quality is produced. SBT thus removes BOD, COD, Ammonia, Nitrogen, Nitrate nitrogen suspended solids bacteria, colour, odour. The SBT is ideal for treating waste water less than 5 MLD.
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Soil Bio Technology (SBT) is an efficient process of synthesis to completely utilize solids and liquids. It is economical in capital and recurring costs. It has a simple looking construction, free from conventional electro-mechanical systems which are prone to breakdowns. It efficiently integrates the physical, chemical and biological processes into a single aerobic system based on natural biophysical and bio-chemical principles. A specified additive is added in a predefined proportion. SBT is a synthesis process which harnesses the energy, carbon and other elements of the waste and converts them to precious “Bioenergy” products like vegetation, energy rich soil, complete Bio-fertilizer and water. It offers a bacterial removal of approx. 99.99% thus ensuring a healthier environment in a sustained manner without any side effects.
Some of the salient features of SBT:
Rejuvenation/creation of soil.
Can be utilizable for all sorts of organic and inorganic molecules present in the effluents
No req. of electricity and chemical (Electricity requirement only for pumping).
Generate Bio-energy
Little space area as per requirement per person (100 litre per day) is 0.021 m2
Anaerobic Baffled Reactor (ABR)An anaerobic baffled reactor (ABR) is an improved septic tank, which, after a primary settling chamber, uses a series of baffles to force all kind of wastewater to flow under and over the baffles as it passes from the inlet to the outlet . The wastewater is introduced into the chamber at the bottom, leading to an enhanced contact with the active biomass which results in an increased retention and anaerobic degradation of suspended and dissolved organic pollutants. ABRs are robust and can treat a wide range of wastewater, but both remaining sludge and effluents still need further treatment in order to be reused or discharged properly (Tilley et al.,2008).
Anaerobic Baffled Reactor
Source: Morel & Diener 2006
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Annexure B: Survey Templates for Village Level Survey
LGD Code
1. Name of the district
2. Name of Block
4. Name of the GP
Sample MH NSK NSK GOV JUL 2017
DPR prepared by
Name Contact number
Survey done by
1 Total population (2011 census survey*) No.
2 Administrative area* Sq km
3 Density/ Sq km Population/Sq km
4 No. of Self Help Group No.
Self Help Group Member No.
5 No. of Swacchagrahis No.
6 No. of Nigrani Samiti members No.
7 No. of Village Water & Sanitation Committee members
No.
1.0 SECTOR BACKGROUND CONTEXT:
(From survey*)
Code State Dist Block GP Month Year
Sample MH NSK NSK GOV JUL 2017
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1.2
VIL
LA
GE
PR
OFIL
E
Tota
l N
o.
ward
s
Po
pu
lati
on
No.
HH
An
ganw
ad
iS
cho
ol
PH
Cs
Co
mm
erc
ial
cen
ters
Mark
et
Relig
iou
s
pla
ceS
lau
gh
ter
Ho
use
Cre
mati
on
G
rou
nd
Oth
ers
1.3
FIN
AN
CIA
LS
TA
TU
S
Fin
an
cial
Year
Inte
rnal
sou
rce
14th
Fin
an
ce
Co
mm
issi
on
/ S
tate
Fin
an
ce C
om
mis
sio
nA
nganw
ad
i
MG
N
RE
G A
MP
L
AD
SM
LA
Fu
nd
Oth
ers
Tota
l b
ud
geta
ry
allo
cati
on
% o
f exp
en
ditu
re
again
st b
ud
geta
ry
allo
cati
on
Tota
l E
xp
en
ditu
re
2016
-17
(Fro
m s
urve
y*)
Fin
an
cial
Year
Inte
rnal
sou
rce
14th
Fin
an
ce
Co
mm
issi
on
/ S
tate
Fin
an
ce C
om
mis
sio
nA
nganw
ad
i
MG
N
RE
G A
MP
L
AD
SM
LA
Fu
nd
Oth
ers
Tota
l b
ud
geta
ry
allo
cati
on
% o
f exp
en
ditu
re
again
st b
ud
geta
ry
allo
cati
on
Tota
l E
xp
en
ditu
re
2015
-16
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1.4 Overview of liquid waste management:
SL.
NoCategory Numbers
Quantity of Liquid Waste Generated
Per day (Ltr)
Grey water Black water
1 Household@
2 Commercial establishments
3 Educational Institutions
4 Medical institution
5 Religious places
Total
(From survey*)
@Rule of thumb: For 50 litres, 50 x (65/100)For 2,3,4 and 5: Water supplied x (65/100)
1.5 ABSTRACT OF DRAIN COVERAGE
Total
length
of road
Pucca
road with
drain
Pucca
Road
with no
drains
Kaccha
road with
drains
Kachha
roads
without
drains
No. HH connected to drains
Connected Not connected
(From survey*)
1.6 DISCHARGE POINT OF HH CONNECTED TO DRAINS
Discharge point
Open
landPond
Agriculture
field
Kitchen
garden
Stabilization
pondPisciculture
Any other
source
HH
connected
to drain
HH not
connected
to drain
(From survey*)
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Map showing (Roads, drains, Water sources, waste water disposal points, water logging points
)
* Vision should outline the specific features of the projects undertaken.
Example:
Gutter mukthgram
Swachhgram
2.0 VISION
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Grey Water Management
A) HH level interventions and capital cost
1. The list of interventions given in the table is exhaustive. All items are not applicable to every village.
2. Fill only the items applicable to the HH under consideration3. Confirm the rates of different items with the competent authority of your area (district)
Greywater
Proposed Intervention for Management grey water from Households
Interventions
HH leach pits
Kitchen gardens
Community plantation
Community leach pit
Centralized Treatment
Units*
Total
No. of HH
No of units
Cost/unit
Total amount
B) Institution level interventions and capitalcost
Data Source: Survey
Total capital cost of HH level intervention= …………….
Greywater
Proposed Intervention for Management grey water from Institution
Interventions
Leach pits
Kitchen gardens
Community plantation
Community leach pit
Centralized Treatment
Units*
Total
No. of Institution
No of units
Cost/unit
Total amount
Data Source: Survey
Total capital cost of commercial establishment level intervention= …….........
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D. Public spaces
(Near Hand pumps/ open wells/ Water tanks/Public toilets/ community toilets)
Proposed Intervention for Management grey water from Institution
Interventions
leach
pits
Kitchen
gardens
Community
plantation
Community
leach pit
Centralized
Treatment
Units*
Total
No. of open space
No of units
Cost/unit
Total amount
Data Source: Survey
Total capital cost for GWM in open spaces= …………….
SL.
NoLiquid Waste Management Quantity
Unit Price Total Cost
(in Rs.)(Rs.)
1 Construction of Soak Pits
2 Construction of Leach Pits
3 Construction of Drainage Facility
4 Construction of drainage channels
5 Stabilization Pond- Construction and Maintenance
6 Construction of filter beds with 2 motors
7 Pre filter chambers
8 Construction of filter beds with motor
9 Pre filter chambers
10 Other GWM Activities (Landscaping of the GP)
11 Total
Centralized treatment facility for GWM
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Estimation of annual cost for operation and maintenance
Grey Water Management
S.No. Maintenance
detail
Norm Estimation of
person days per
year
Daily Wage
(Rs. Per
Day)
Annual Labour
Cost (Rs. Per
year)Total
A B C D E = C X D
1 Community Leach pit
a Cleaning of silt chambers
Chambers to be cleaned every three weeks; i.e 18 times a year. 1 person can clean 5 chambers in a day
= (Number of chambers ÷ 5) x 18
b Cleaning of Leach pit
Community Leach pit to be cleaned once a year. 1 person can clean one leach pit in a day.
= Number of community leach pits x 1
c Removal of occasional blockages in pipelines
3 days per community leach pit per year
= 3 x number of community leach pit
Total Rs.
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ANNEXURE C: ROLE OF GRAM PANCHAYAT
There are 2,62,547 Panchyat Raj Institutions in the country. They have been constitutionally mandated to carry out mandatory, general and sectoral functions. Under the article 243G of the Constitution, Section 11 was introduced listing 29 sectoral functions that inter-alia include sanitation to achieve the mandate of Self Government, Economic Development and Social Justice at GP level. These 29 subjects are in the realm of GPs and Sarpanches can take up the grey water management works.
Model Panchayat Code 2009 states:
29. Panchayats responsibility to provide civic amenities in its jurisdiction.-
Panchayats shall have the power to:
To maintain the sanitation, conservancy, drainage, water works, source of water supply;
Panchayats’, ‘Public Health & Sanitation’ subjects of State List
1. State’s PRI Acts provide power to GPs
a. To levy & collect Sanitation fees/cess
b. To control & take action against person creating insanitary activities
2. State’s PRI Acts states duties of PRIs
a. To provide sanitation facilities, SLRM, all activities to prevent insanitary situations
For example,
Karnataka & Kerala PRI Act states - Clear roles of each tier and for Gram sabhais defined in Activity mapping. GPs are responsible for implementing sanitation plan and are also empowered to fine and regulate sanitation functions at GP level.
Karnataka Act also states GPs (Sanitation and Public Health) to
Cleaning and preservation of drains, and other public places.
Establishment and maintenance of liquid waste disposal system; Collection, segregation and transport of solid waste to multi village solid waste management plants
These works are to be taken up as part of the Gram Panchayat Development Plan. This plan is an intended action based on local priorities. Funding for implementing the grey water management works can be accessed through Finance Commission devolutions made by the State,
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convergence with programmes like MGNREGA, PMAY and NRLM. It is pertinent to mention here that the 14th Finance Commission during its period (2015 – 2020) has allocated Rs.60,687 crores to Panchayats for discharging their assigned functions.
The GPDP has a timeline for preparation and approval of plans. It starts with the planning stage at May and ends with the approval of GPDP by December. The GPDP can be prepared with the assistance of the Planning Tool Plan Plus developed by the Ministry of Panchayati Raj, Government of India. Compilation of GPDP plans of all villages at district level would result in the district level plan for grey water management.
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ANNEXURE D: IEC STUDY FOR GREY WATER MANAGEMENT IN RURAL AREAS
1 States should create an IEC tool kit
2 The campaign could be called - “Be Grey Water Smart”, or anything that the State deems fit in short, brand the campaign so that it becomes an idea which is quickly absorbed by villagers.
3 The messages communicated should be no more than 5. They should be crisp and call for action.
Messages could be on the following aspects:
Type of messages Target audienceMethod of
outreachContent
1. Advocacy – “Why” aspects of Grey Water Management.
Meant for Collectors/ CDOs/ZP Presidents
Radio Jingle, Whatsapp Videos.
Need for tackling Grey water which is a health and environment hazard and at the same time an opportunity to tackle water crisis.
2. What exactly needs to be done – “What”aspects of the Grey water strategy
BDOs/ Engineering Department/ EEs
(a) Posters
(b) Flipcharts
(c) Simple games whereby rural households can be triggered.
Triggering tools
(a) Technical Posters detailing out the technology options.The poster will give link to Website where the technology reference book is loaded. Tools like flip charts can be used to show step by step construction methods based on soil and terrain.
(b) People mobilization -“Jan Andolan” Importance of involving rural people.
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Type of messages Target audienceMethod of
outreachContent
3. How exactly should it be done
“How to do” aspects
Sarpanch, Gram Sachiv, Mason, J.E.
1. Radio talks
2. Village Wall Paintings
3. Demo models of soak pits, leach pits in select GPs and in training centers like SIRD.
Exact step by step process at village level.
(A) Involve community Jan Bhagidari for creating the vision of a clean village/triggering tools.
(B) Inform rural HHs
That grey water and black water should not mix and the health hazards associated with contamination
The message should be about the importance of not dumping solid waste in grey water as it contaminates and chokes the flow of grey water.
How to construct leach pit / soak pit insitu.
How to maintain the leach pit / soak pit.
How to construct and maintain a community grey water treatment structure.
Ministry of Drinking Water and Sanitation