Kolkata: West Bengal has formally notified its State Policy on Safe Reuse of Treated Wastewater, establishing a framework for directing treated municipal wastewater towards suitable non-drinking applications.
The Urban Development and Municipal Affairs Department issued the policy under notification number 543-WBSPMG-99099(99)/27/2025 on 14 July 2026. The final notification follows the publication of a draft policy in March 2026 for stakeholder consultation.
The policy is intended to reduce avoidable demand for freshwater by expanding the use of reclaimed water in industry, construction, residential and commercial developments, public facilities, agriculture, landscaping, road cleaning, toilet flushing and firefighting.
The policy sets a target for treated municipal wastewater to meet at least 20% of West Bengal’s overall industrial water requirement by 2030. Industry-level reuse expectations are reported to range from approximately 10% to 40%, depending on water demand, process requirements, location and the feasibility of receiving treated water.
The 20% target should be treated as a state-level policy objective rather than a measurement of current reuse. Its achievement will depend on the availability of adequately treated wastewater, proximity of industries to sewage treatment plants and the development of commercially viable supply systems.
Industrial applications may include:
Cooling systems
Equipment and floor washing
Boiler-feed preparation after additional treatment
Process-water applications where technically suitable
Landscaping and green-belt irrigation
Firewater storage
Construction and dust suppression
Toilet flushing and other utility requirements
Industries requiring higher-quality process water may need additional treatment through ultrafiltration, reverse osmosis, ion exchange, activated carbon or advanced disinfection.
The policy promotes the use of treated wastewater within residential complexes and other large developments for applications that do not require potable-quality water.
The earlier draft proposed reuse in multistorey buildings, gated communities, public institutions, commercial establishments, hotels, airports and major railway stations. It also encouraged new residential projects requiring environmental clearance to incorporate systems for recycling treated wastewater.
Such projects may require:
On-site or decentralised sewage treatment
Separate reclaimed-water storage
Dual plumbing
Clearly identified non-potable pipelines
Controls against cross-connections
Metering and consumption monitoring
Routine sampling and disinfection
Trained operation and maintenance personnel
Treated wastewater should not be connected to drinking-water systems. Its use must remain restricted to applications permitted under the applicable quality standards.
A successful reuse programme requires more than treatment capacity. Reclaimed water must be transported reliably from sewage treatment plants to industries, farms, construction sites and other users.
Implementation may therefore generate demand for:
Tertiary treatment systems
Pressure filtration and membrane technology
Ultraviolet, ozone and chlorination systems
Reclaimed-water pumping stations
Dedicated transmission pipelines
Storage reservoirs
Tanker-filling facilities
Online water-quality analysers
Flow meters and remote monitoring
Automation and supervisory control systems
Where treatment plants are located far from potential users, the cost of pumping and pipeline construction may affect commercial viability. Early demand mapping will be necessary to identify large and dependable consumers located within practical supply distances.
Treated wastewater cannot be regarded as suitable for every application solely because it has passed through a sewage treatment plant.Water used for industrial cooling, agriculture, landscaping, construction or toilet flushing may require different quality specifications. Monitoring may include
Biochemical oxygen demand
Chemical oxygen demand
Total suspended solids
Turbidity
Faecal coliform
Residual disinfectant
pH
Salinity and conductivity
Nutrients
Heavy metals
Emerging contaminants
The policy framework assigns an important monitoring role to the West Bengal Pollution Control Board, including oversight of contaminants that may affect safe reuse.Industries using reclaimed water will also need to assess compatibility with cooling towers, boilers, membranes, heat exchangers and manufacturing processes. Additional treatment may be required to control scaling, corrosion, microbial growth and product-quality risks.
The policy framework proposes the development of databases and a GIS-enabled management system to assess water demand, wastewater generation, treatment capacity and reuse performance.
Such a system could help authorities:
Map sewage treatment plants and potential users
Track treated-water production and consumption
Monitor water quality
Identify unused treatment capacity
Plan pipelines and storage infrastructure
Compare freshwater and reclaimed-water demand
Record operational interruptions
Measure progress towards reuse targets
Reliable data will be essential because the quantity of wastewater treated does not necessarily equal the volume available for reuse. Losses, inconsistent plant operation, seasonal demand and water-quality failures can reduce the amount that can be delivered to users.
The policy also considers pricing and commercialisation of treated wastewater so that urban local bodies can recover part of the cost of treatment, pumping, storage and distribution
A workable tariff will need to balance two objectives:
Reclaimed water should remain attractive compared with freshwater or tanker supplies.
Revenue should support reliable operation and maintenance of treatment and distribution systems.
Long-term purchase agreements with industrial clusters, power plants, construction agencies and other bulk users may improve project viability by creating predictable demand.Tariffs may need to reflect water quality, distance from the treatment plant, pumping requirements, additional treatment and delivery method.
The notified policy could open opportunities for technology manufacturers, EPC contractors, consultants and service providers working across municipal and industrial water management.
Potential areas include:
Upgradation of secondary treatment plants to tertiary standards
Industrial polishing and high-recovery treatment systems
Decentralised wastewater recycling
Reclaimed-water networks
Membrane filtration and disinfection
Online compliance monitoring
Sludge handling and resource recovery
Operation and maintenance contracts
Water audits and reuse feasibility studies
Public–private partnerships
Digital water-management platforms
The scale of these opportunities will depend on city-level action plans, project funding, industrial participation and the publication of detailed technical and procurement requirements.
West Bengal’s policy represents a transition towards treating municipal wastewater as a managed resource rather than solely as a waste stream.
Its long-term impact will depend on whether the state can connect treatment capacity with dependable users while maintaining appropriate water quality. Dedicated pipelines, pricing mechanisms, enforcement, transparent monitoring and competent operation will be central to implementation.
The immediate priorities are likely to include mapping supply and demand, identifying priority treatment plants, securing bulk users and preparing local reuse projects that are technically and financially sustainable.