Land for Irrigation (irrigation discharge)

Land for irrigation is one of the four effluent disposal modes in India's discharge standards: treated effluent is applied to agricultural land as irrigation water rather than released into a water body or sewer. It has its own column of limits, some relaxed (suspended solids up to 200 mg/L versus 100 mg/L for inland surface water, since the soil filters particles) and some specifically controlled for soil and crop protection — parameters such as sodium, boron, and dissolved salts (electrical conductivity / TDS) matter here because they affect soil structure and crop health in ways irrelevant to a river discharge.

The logic is beneficial reuse: properly treated effluent carrying nutrients can substitute for freshwater irrigation and supply crop nutrition, turning a disposal problem into an agricultural input. But the soil and crop become the receiving environment, so the controls shift toward protecting long-term soil health (salinity, sodicity, heavy-metal accumulation) and food safety, not just immediate aquatic toxicity. Heavy metals are tightly limited because they accumulate in soil and enter the food chain.

For recyclers, the directly relevant case is the CBG/biogas sector, where the nutrient-rich liquid digestate is a natural candidate for land application — it carries ammoniacal nitrogen, phosphorus and potassium that benefit crops. The existing glossary already treats digestate as a fertiliser/soil amendment. Using digestate liquor for irrigation aligns the effluent-disposal route with the plant's product strategy, but it must meet the land-application standards and the soil-protection parameters.

The practical approach for a CBG operator is to position liquid digestate as an irrigation and fertigation input rather than a waste to be discharged, while controlling salinity (EC/TDS), pathogen content and any heavy-metal load to the land-application standards and Fertiliser Control Order requirements. This converts the cost of effluent disposal into product value, but requires monitoring the soil-relevant parameters that a water discharge would not need.