**4.5. Selection of appropriate wastewater treatment technology**

Properly planned use of municipal wastewater alleviates surface water pollution problems and not only conserves valuable water resources but also takes advantage of the nutrients contained in sewage to grow crops. Based upon the above analysis, it was evident that untreated wastewater discharge towards Rawal dam was a serious issue due to drinking nature of the storage and remedies were essential. A scientifically designed septic tank with multiple compartments was considered to be the most feasible wastewater management solution due to typical geographical and socio-economic conditions of the study area. Al‐ though over 98% area, already these were prevailing but these were just dug holes without considering any scientific justifications. If a properly planned septic tank could be developed and replaced in entire area, it can reduce the wastewater contamination issue at Rawal dam very significantly. As septic tanks can be 60%–70% efficient in reducing wastewater loads, dilution through freshwaters from Rawal watershed area will help in mitigating remaining impurities. To address these issues, conservation practices, such as conservation tillage, filter strips, land retirement, and nutrient management can be adopted [25]. Other policy level planning should be to (a) encourage reduction, recycling, and reuse of municipal and industrial solid and liquid wastes; (b) develop and enforce rules and regulations for proper management of municipal, industrial, hazardous, and hospital wastes; (c) develop environmental risk assessment guidelines for existing industries as well as new development interventions; and (d) adopt cleaner technology, implement pollution control measures, and compliance with the environmental standards.
