economic and environmental analysis of wastewater collecting and treatment

the increase in water demand and its services due to population growth and the raising of the standards of living, health, and hygiene along with the limitation of water resources, droughts, and climate change has attracted water specialists and planners to explore the use of unconventional water resources, such as sewage and saline waters. moreover, industrial and rural wastewater disposal and the penetration of their pollutants to the surface- and ground-water resources is an important concern in many countries, including iran. wastewater treatment and its application for various uses reduces the negative externalities of wastewater release on the environment and human health. accordingly, in this paper the methodology for economic and environmental evaluation of wastewater collection and treatment, and the necessary holistic view taking into account the issues that must be considered in this regard has been addressed. furthermore, the steps and framework of a modified cost-benefit analysis of the tehran wastewater collection and treatment plan have been discussed.