Water, sanitation, and hygiene (WASH) directly impact human health and have far reaching consequences when ignored. India is one of the fastest developing economies, but when it comes to WASH indicators, it continues to lag behind. With a population of over 1.2 billion, there is a mounting and urgent need to address sanitation. Solid and Liquid Waste Management SLWM) is one of the key components of Swachh Bharat Mission (SBM) (G), launched with the objective of bringing improvement in cleanliness, hygiene and the general quality of life in rural areas. SLWM is the collection, transportation, processing, recycling, treatment, and disposal of waste material in a scientific manner.
The following guidelines presents a basic, quick introduction to Solid Liquid Waste Management (SLWM) in rural areas. It is geared, particularly for district administrators to help focus on SLWM along with Open Defecation Free (ODF) activities.
Waste is any item beyond use in its current form and discarded as unwanted. It can be solid or liquid with respective management methods.
In rural areas, examples of solid waste include wastes from kitchens, gardens, cattle sheds, agriculture, and materials such as metal, paper, plastic, cloth, and so on. They are organic and inorganic materials with no remaining economic value to the owner produced by homes, commercial and industrial establishments. Most household waste in rural areas is organic, with little inorganic material, and is non-toxic. Because of its environment - friendliness, composting is a highly suitable method of waste management in rural areas.
When water is used once and is no longer fit for human consumption or any other use, it is considered to be liquid waste . Wastewater can be sub categorised as industrial and domestic.
SBM focuses on generating awareness and providing community managed sanitation systems. To implement SLWM initiatives economically and efficiently, ownership at grassroot level and community involvement at all stages is critical.
Information, Education, and Communication (IEC) interventions should focus on SLWM to create a demand for a sustainable system. This must lead to setting up systems for waste disposal in such a way that it has tangible impact on the population. The community/Gram Panchayat (GP) has to be encouraged to come forward and demand such a system, which they can subsequently operate and maintain.
Awareness and education campaigns should aim for panchayat officials, elected representatives, schools, non - governmental organisations (NGOs ) working in villages, shop keepers, families, and general public .
The GP functionaries would be responsible for design, implementation, operation and maintenance (O&M) of SLWM systems with support from respective state governments. Mechanisms for involving third parties in construction and management activities under GP and community supervision can be explored. In such cases, absolute clarity in the roles and responsibilities of various stakeholders in managing SLWM systems is a must. Community contribution and appropriate user charges for sustainable SLWM initiatives are also desirable.
All GPs are to be targeted for coverage with an SLWM project. SLWM projects for each GP should be part of Annual Implementation Plan (AIP) of a district. The AIP should be approved by State Level Scheme Sanctioning Committee. Each individual SLWM project may be approved at the District Water and Sanitation Committee (DWSC) level according to the technical and financial rules of the individual states. Every state should have at least one SLWM consultant at the state level and one SLWM consultant in each District Water and Sanitation Mission (DWSM) / DWSC to guide preparations for SLWM projects.
Solid waste management : Composting Methods
|Technology||Description||Advantages||Disadvantages||Conditions for use|
|NADEP method||Composting takes place in a rectangular brick tank with aeration holes. Organic material is added in layers and compost is ready in almost 3 months||Composting can be done on a larger scale than using piles. All nutrients are retained in the tank so resulting compost is more nutrient rich.||Tanks work in 3 month rotations so at least 2 are needed which increases the cost. Large quantities of soil and water are needed which can be difficult to transport in some areas. The entire tank should be filled within a maximum 48 hour period (24hrs is better).||Tanks can be built in all conditions. The thatch roof protects the tank from moisture. Tank should be monitored to check for cracking of seal which would allow moisture to escape. Tanks require space and a lot of initial material so a community approach is better, using a communal space for the tank and agreeing the date for bringing material/ filling the tank.|
|Bangalore method||Waste is composted anaerobically in a pit. Compost is ready in 6 - 8 months||Can accept municipal waste and night soil. Good for dry areas and no O+M is needed||Cannot be used in wet areas as the pit may become waterlogged. Gases produced can smell and the pit requires quite a large space. Composting process is slow||Useful in areas where the use of piles is limited by severe weather conditions e.g. strong winds and sun. Can be done at the household level where space permits as no O+M is required. Very cheap compared to tank methods as no infrastructure is required|
|Indore method||Waste is cut into small pieces and spread 10 - 15cm thick above ground or in a pit. Compost is ready in 4 months||No infrastructure is needed and process is relatively quick||Nutrients are lost to the soil. Regular turning is needed (every 5 days). Cannot be used in wet areas or areas with heavy rainfall due to waterlogging||Pit/heap is unprotected so may need some protection from animals/children etc. A windbreaker can be used to reduce effects of drying out. Very cheap compared to tank methods as no infrastructure is required.|
|Vermicomposting||Composting using a specific species of worms to break down waste Compost is ready in 3 - 4 months but compost must be removed in stages as the worms process it||More efficient than normal composting and produces richer compost.||Needs a vermitank or verminbed and worms need to be bought or grown which increases cost . Needs more O+M than normal||Worms’ optimal temperature range is 15 - 35 degrees Celsius. Lower temperatures hamper reproduction and higher temperatures kill the worms or make them leave. Worms are very sensitive to drought so use in very dry areas is not recommended unless a reliable water source is available.|
|Bio gas from organic solid waste||Bio gas is created by the decomposition of organic waste in anaerobic conditions. The resulting gas can be let off into the atmosphere or it can be tapped for burning as a fuel. As well as the biogas, the process also produces a slurry which can be used as a nutrient rich fertilizer.||Gas accumulation rates are slower than rates of use but for areas reliant on wood as a fuel for cooking biogas provides an excellent alternative.||The biogas plant can be linked to the family or community toilet or it can be a standalone system to which wastes are added. There are many different designs available. The choice of design will be influenced primarily by the desired capacity, the space available to install the plant, the type of feed material (cattle dung has higher gas producing capacities than human waste) and the finances available for construction. Waste should be added daily to ensure continuous gas production. Stoves, cookers or lamps must be converted to accept biogas but the gas itself burns without odour.|
Liquid waste management : Wastewater Treatment Technologies
|Technology||Whether Natural or Built||Aerobic/ Anaerobic/ Mixed||Expected effluent quality (low, medium, high)||Area Requirement (m 2 /person)||Power requirement kWh/person/year||Prevalence in India|
|Waste Stabilisation Pond System||Natural||Mixed||Medium to High||2.0 – 3.0||Nil||All over India|
|Duckweed Pond System||Natural||Aerobic||Medium to High||2.5 – 6.0||Nil||Greater number in the state of Punjab|
|Constructed Wetland||Natural||Aerobic||Medium||1.5 – 2.5||Nil||Less Implementation experience in India|
|Upflow Anaerobic Sludge Blanket||Built||Anaerobic||Low||0.1 – 0.2||Only for pumping||All over India in urban areas, but very less experience in rural areas|
|Anaerobic Baffled Filter||Built||Anaerobic||Low||0.2 – 0.4||Nil||All over India|
|Package Aeration System||Built||Mixed||High||0.1 – 0.15||20 – 30||All over India|
|Extended Aeration System||Built||Aerobic||High||0.1 – 0.2||15 – 25||All over India|
|Sequencing Batch Reactor System||Built||Aerobic||Very High||0.05 – 0.1||10 – 20||All over India|
|Soil Bio Technology||Natural||Aerobic||Very High||0.021||40 – 50 kWh/MLD to pump wastewater for distribution across the reactor bed||All over India|
For details of technologies, visit the following.
Government of India has developed a detailed statistical analysis to identify factors that may be necessary for measuring cleanliness across India in order to raise awareness about cleanliness and to instil a sense of competitiveness amongst villages, GPs, Blocks, Districts and States. Based on several consultations with states and experts and a large survey involving over 70,000 households in 75 districts across the country, Cleanliness Index and SLWM index have been defined.
Cleanliness index captures the overall cleanliness of a village including village households which have access to and are using safe toilets and environmental friendliness. SLWM index captures environmental friendliness as evidenced by absence of litter around houses and public places and no stagnant water around house holds. SLWM index is derived out of Cleanliness index as per the following:
Village Cleanliness Index (C) is defined as C = 0.4*X1 + 0.3*X2 + 0.1*X3 + 0.2*X4
In addition, Village SLWM Index is defined as S = 0.5*X2 + 0.17*X3 + 0.33*X4 where,
X1 = % of households having access to safe sanitation
X2 = % of households having no litter around them
X3 = % of households having no stagnant waste water around them
X4 = % level of litter free around public places
Gram Sabhas are responsible to estimate the various factors defined above that comprises the cleanliness index.