Decentralized wastewater treatment system that treats used water locally using natural and low-energy processes.
Pond-based treatment systems that use sunlight and microbes to treat used water naturally.
Waste Stabilization Ponds (WSPs) are large, human-made water bodies in which used water are treated by naturally occurring processes under the influence of sun light, wind, microorganisms and algae. The ponds can be used individually, or linked in a series for improved treatment. There are three types of ponds in series (1) anaerobic, (2) facultative and (3) aerobic (maturation), each with different treatment and design characteristics.
Suitability:
Waste Stabilization Ponds (WSPs) are appropriate for towns and cities with large, open, and unused land areas, preferably located away from residential zones and public spaces. They are particularly well-suited for tropical and subtropical regions, where ample sunlight and warm temperatures enhance the natural treatment process. WSPs are especially effective for treating used water collected from drain endpoints, particularly where high volumes of used water are generated. The treated effluent is generally of a quality suitable for irrigation and agricultural reuse.
Pros/Cons:
Pros: WSPs are low capex and opex based system, can be built and repaired with locally available materials, system does not require electrical energy, basic skill requirement for O&M, can produce good quality effluent which is safe for its reuse.
Cons: WSPs require a large area. Ponds require regular sludge removal (especially anaerobic pond) to avoid excessive accumulation, as removing large volumes at once can be time-consuming and difficult to manage. They may produce undesirable odors, and mosquito control is required.
O&M requirement: Scum that builds up on the pond surface should be regularly removed, aquatic plants that are present in the pond should be removed as they may provide a breeding habitat for mosquitoes and prevent light from penetrating the water column. The anaerobic pond must be de-sludged approximately once every 2 to 5 years. De-scumming and de-sludging of ponds need to be carried out as per the schedule to avoid odor nuisance.
|
Parameter |
Design Value |
Unit |
|---|---|---|
|
Influent Characteristics |
||
|
BOD |
250 |
mg/l |
|
COD |
500 |
mg/l |
|
Pond Configuration |
||
|
Number of Anaerobic Pond (AP) |
1 |
No |
|
Number of Facultative Pond (FP) |
2 |
No |
|
Number of Maturation Pond (MP) |
3 |
No |
|
Slope of each pond |
1:1.5 |
- |
|
Effluent Characteristics |
||
|
BOD (At PGF Outlet) |
< 30 |
mg/l |
|
COD (At PGF Outlet) |
< 250 |
mg/l |
• It is assumed that the site is a fairly level site with minor variations in levels.
• The Design Water Table for the design of the civil units of the STP is assumed at 5.0m below the Natural Ground Level.
• There is vehicular access available to the site.
• The site is fairly level ground, free of any structures, large trees requiring cutting permission, any kind of underground or overhead utilities, etc. except for small shrub's, vegetation, etc.
• The soil profile of the site involves earth work excavation in soil only, excavation involving rock blasting is not necessary.
• The site is not a low-lying area or marshy land or sewage farm, etc.
• The site is with original soil profile, without deep filling or overburden.
India’s rural sanitation sector has witnessed significant progress under the Swachh Bharat Mission Grameen (SBM-G), with increasing emphasis on sustaining Open Defecation Free (ODF) outcomes and strengthening Solid and Liquid Waste Management (SLWM) systems across villages. As rural communities continue to evolve and generate higher volumes of greywater and wastewater, there is a growing need for decentralized, cost-effective, and sustainable rural used water management solutions that are technically sound and easy to implement.
Despite the availability of various treatment technologies and management approaches, Gram Panchayats, Rural Development Departments, and implementation agencies often face challenges in selecting appropriate technologies, preparing technical designs, estimating costs, and planning site-specific interventions. The lack of standardized technical resources and easy access to implementation-ready designs further slows down the execution of rural sanitation infrastructure.
To address these challenges and support the effective implementation of rural used water management systems, WASH Institute has developed this dedicated web-based Rural Used Water Management Portal. The portal is envisioned as a comprehensive technical decision-support platform to assist states, districts, blocks, Gram Panchayats, and practitioners in planning and implementing sustainable rural sanitation infrastructure.
The portal provides a curated repository of commonly adopted rural treatment technologies and management systems, including soak pits, leach pits, waste stabilization ponds, DEWATS, drain-end treatment systems, co-treatment models, FSTPs and other decentralized greywater management solutions suitable for rural contexts. Each technology package includes standard design drawings, technical specifications, implementation guidance, and quantity estimates (BoQs) that can be readily adapted for field implementation.
The technical resources available on the portal have been prepared by experienced sector experts in alignment with CPHEEO guidelines, SBM-G operational guidelines, and established field practices. The technologies featured on the portal have been successfully implemented across multiple villages and states, ensuring their practicality, scalability, and suitability for diverse rural conditions.
By making standardized designs and implementation resources easily accessible, the portal aims to strengthen planning capacities, reduce duplication of technical efforts, improve the quality of infrastructure implementation, and accelerate the adoption of safe and sustainable rural used water management systems across India.
Importantly, the portal is designed as a dynamic and evolving knowledge platform rather than a static repository. It will continue to expand through contributions from sector practitioners, government departments, and technical institutions. Future enhancements will include state-specific schedule of rates, GIS-based planning support, case studies, operation and maintenance guidance, and real-time cost estimation tools to further support rural sanitation planning and implementation.
Local governments follow staged planning for grey water management projects — planning and project formulation, DPR preparation, tendering, construction, and operation & maintenance. This portal supports the tendering stage by providing standardized technical drawings and cost estimates.
The designs, drawings, and bills of quantities (BoQs) provided on this portal are intended for reference purposes only and cannot be used directly for construction. Validate design assumptions, adopt locally applicable Schedule of Rates, and ensure compliance with applicable national or state-level standards.