**5. Conclusions**

**Figure 11.** Organic nitrate generated under various scenarios.

196 Wastewater Treatment Engineering

**Figure 12.** Organic phosphorous generated in different sub-basins under three scenarios.

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

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

The issues related to water quality and quantity management involves numerous technical, socio-economic and environmental factors and coupled with complex spatial variability become highly complicated. The results of the integrated field based investigations and modeling approach exhibited variable responses of surface runoff and water quality to changing conditions of urbanization and deforestation. The concentration of the pollution parameters was found higher from the densely populated catchments containing extensive industrial and commercial activities. Temporal wastewater analysis indicated a significant impact of seasonality on the contaminants' population levels. The wet season of monsoon (July–September) has lowered almost all key parameters of pollution as compared to the dry season, except nitrate and nitrite, which indicated increasing trends during the wet period because runoff also taken animal, human, and poultry wastes dumped in or near the drainage network. Statistically, the variability was significant on the temporal scale and non-significant on the spatial scale—an indication that wastewater contamination is affected by the seasons. If planned properly, the municipal wastewater can be used not only for conserving valuable water resource, but also for taking advantage of the nutrients contained in sewage to grow crops. It is desirable to develop mathematical techniques to aid decision makers in formulating cost-effective and environment-friendly plans and policies for wastewater management. The modeling efforts using SWAT biophysical water quality model would enhance the capability of decision makers in exploring comprehensive and ambitious plans for managing water systems. The adopted approach would provide an effective decision support tool for evalu‐ ating better management options to reduce negative impacts of wastewater and contaminants for sustainable agro-environment in future.
