Kimmel Chamat November 29th, 2009
INTEGRATED APPROACH TO WASTEWATER MANAGEMENT
SAVING, RECYCLING AND CLEANING
“Sustainability is the aggregation
of what you spend and you waste”
The treatment and recycling of urban wastewater and storm water is a core issue to make our cities more sustainable. Thehistorical deterioration of freshwater resources, in addition to rapidly expanding populations -particularly in urban areas- and the environmental alterations related to climate change endanger the capacity of nature to provide freshwater for human life in many places of the world. Better and innovative manners to manage and reuse waste and storm water will reduce the pressure on freshwaterresources while enhancing the quality of water ecosystems. The aim of this research is to portray an integrated approach to wastewater and storm water management in architectural and urban spaces, on the basis that the availability of clean drinking water is closely related to the appropriate disposal of wastewater.
The negative effects of urban wastewater in aquatic environments and human health iswell known. Urban wastewater effluents can destroy the aquatic life and become a serious threat for human health. According to the United Nations, Division of Sustainable Development, untreated wastewater can result in "fish kills, destruction of aquatic habitats by sedimentation, acute and chronic toxicity to aquatic life from chemical contaminants, as well as bioaccumulation of chemicals in thefood chain" In regard to the impact in human health, "water contaminated by human, chemical or industrial wastes can cause a number of diseases through ingestion or physical contact. Water-related diseases include dengue, filariasis, malaria, onchocerciasis, trypanosomiasis and yellow fever" It is the vicious circle of pollution: people don’t manage appropriately the waste, hence waste pollutethe environment and then come back to human life with unpredictable consequences.
The situation is especially critical in the developing world. “In developing countries, 300 million urban residents have no access to sanitation and it is mainly low income dwellers who are affected by lack of sanitation infrastructure. Approximately two-thirds of the population in the developing world has nohygienic means of disposing excreta and an even greater number lack adequate means of disposing of total wastewater (Rose, 1999). “There is at present hardly any infrastructure for the effective treatment of sewage in developing countries. Municipal sewerage and the extent of domestic and industrial wastewater treatment are inadequate in most urban situations”. Uncontrolled growth, lack of urbanplanning and poverty make traditional sewage systems difficult to implement and maintain. In the city f Cali, Colombia, of instance, all the wastewater is discharged to the Cauca River with no previous treatment. After a massive discharge of waste to the river, the water, already polluted, is treated and cleaned to provide drinking water for the whole city. It is a classic example of a vicious circle ofpollution and a no closed-loop approach.
Figure 1. The vicious circle of pollution
An Integrated Approach to Wastewater Management
A sustainable approach to wastewater management will include at least three phases: saving, recycling and cleaning water after use. To achieve a proper integration of the three phases, a closed-loop method is fundamental. A closed-loop system consistsbasically in local treatment and reuse of wastewater, without depending on centralized infrastructure. It allows a continually reusing of the water in a cyclical way, upon the fact that “wastewater is composed of over 99% of water”. “Non centralized systems are more flexible and can adapt easily to the local conditions of the urban area as well as grow with the community as the populations increases...