Managing wastewater is intrinsically linked to management of the entire water chain. How we use and reuse water is the key to successfully meeting the vast water requirements of an urban population twice its current size, expanding agriculture to feed another three billion people and satisfy rising demand for meat, while coping with increasing food waste. (UNEP 2000)
Wastewater management refers to the process in which wastes and wastewater are managed from the point of generation to the point of use or ultimate disposal. The hardware answer to wastewater management are sanitation systems (on-site and off-site). Sanitation systems are a combination of different functional units that together allow managing and reusing or disposing the different waste flows from households, institutions, agriculture or industries in order to protect people and the environment. The systems are designed to address the whole water cycle as well as the nutrients cycle, from the toilet where wastewater is generated, over the collection, treatment up to reuse or discharge. In order that sanitation systems function reliably, the technical expertise for the installation of functional units as well as their management, operation and maintenance must be guaranteed. (SSWM 2016e)
Wastewater is already being used for irrigation and fertilization and can continue to expand this role, particularly for peri-urban or urban agriculture and home gardens. However, maximizing water efficiency in the entire water chain including before water enters the cities, and reducing production of wastewater should be a primary goal throughout the entire management scheme. With proper management, wastewater can be an essential resource for supporting livelihoods. Wastewater treatment and reuse in agriculture can provide benefits to farmers in conserving fresh water resources, improving soil integrity, preventing discharge to surface and groundwater waters, and improving economic efficiency.
Defusing the wastewater crisis is achievable and measurable, but requires an entirely new dimension of investments. Currently, most of the wastewater infrastructure in many of the fastest growing cities is either non-existent, inadequate or outdated and therefore, entirely unable to keep pace with the demands of rising urban populations. Experience has shown that substantial investments done in the right manner can provide the required returns. However, finding a solution will require not only investment but also carefully integrated national to municipal water and wastewater planning that addresses the entire water chain – drinking water supply, production and treatment of wastewater, ecosystem management, agricultural efficiency and urban planning. (UNEP 2000)
Wastewater management has many associated environmental benefits, enabling ecosystems within watersheds and the productive coastal zone to thrive and deliver services on which healthy communities and economies depend. Inadequate management in turn incurs heaving costs, threatening to undermine these ecosystems. However, often the value of these benefits is not calculated, because they are not determined by the market due to inadequate property rights, the presence of externalities and the lack of adequate information. Valuation of these benefits is nevertheless necessary to justify suitable investment policies and financing mechanisms. (Hernández-Shancho et al. 2010)