Bengaluru: Concerned over vegetables and leafy greens cultivated using polluted water in the peri-urban belts of Bengaluru, Mysuru and other rapidly expanding cities, Karnataka horticulture department has drawn up a plan to supply scientifically treated wastewater for horticultural crops. The department has decided to initiate discussions with Bangalore Water Supply and Sewerage Board (BWSSB) and Karnataka Urban Water Supply and Drainage Board (KUWSDB) to establish additional sewage treatment plants (STPs) and create infrastructure to channel tertiary-treated water to farmers, replacing the use of untreated sewage for irrigation.The initiative comes amid repeated reports of vegetables being grown using contaminated lake water, stormwater drains and untreated sewage due to acute water shortages faced by farmers. Experts have consistently warned that such practices could expose crops to harmful contaminants, including disease-causing pathogens, heavy metals and industrial pollutants, posing potential health risks to consumers while degrading soil quality over time.Senior horticulture officials said the department intends to build a reliable network for supplying tertiary-treated wastewater that meets prescribed quality standards for agriculture. The recycled water will be used to irrigate vegetables, fruits, flowers and other horticultural crops grown around major urban centres, reducing dependence on freshwater while discouraging farmers from drawing polluted water from drains and sewage channels.Unlike KC Valley Project, where treated wastewater from Bengaluru is primarily used to recharge groundwater in Kolar and Chikkaballapur districts, the new proposal seeks to directly utilise tertiary-treated water for irrigating horticultural crops after ensuring it meets the required safety standards.“The objective is two-fold. We want to conserve precious freshwater resources while ensuring that farmers do not resort to using untreated wastewater for irrigation. We will soon hold consultations with the urban development department to explore the establishment of additional STPs and the creation of infrastructure to supply treated water to horticultural fields around major cities. We have also directed our district officials to submit detailed proposals to both BWSSB and KUWSDB. Both agencies have, in principle, agreed to establish STPs for this purpose,” said R Girish, IAS, secretary, department of horticulture.The proposal draws inspiration from a successful model already in operation at Lalbagh Botanical Garden and Cubbon Park, where tertiary-treated water supplied through BWSSB-operated STPs is used to irrigate trees, plants and lawns. Officials said borewells alone are inadequate to meet the parks’ irrigation requirements, particularly during the summer months when water scarcity intensifies. Wastewater generated from surrounding localities is collected, scientifically treated and reused within the gardens, significantly reducing dependence on freshwater.Officials believe the model can be replicated across Karnataka’s urban centres, where crores of litres of wastewater are generated every day. If recycled and safely reused for agriculture, they say, it could provide a dependable source of irrigation to hundreds of horticulture farmers, improve crop productivity and enhance the safety of vegetables reaching consumers.
