Construction of nine wastewater treatment plants and sewage network in the counties of Tehran Province will start in the next Iranian calendar year (March 2021), managing director of Tehran Province Water and Wastewater Company said.
“The counties include Qarchak, Varamin, Pakdasht, Qods City, Rudehen, Baharestan, Rudbar-e Qasran, Damavand and Firuzkuh,” Mohammadreza Bakhtiari was quoted as saying by Mehr News Agency.
“If we really want a decent future for Tehran Province, it is crucial to seal water wells used by farmers and supply their needs with treated wastewater,” Bakhtiari said.
Expansion of wastewater network has been a priority in the sprawling capital in recent decades, but lack of funds in addition to rapid expansion of urban areas has slowed, and at times hampered, the process, the official noted.
He warned that water wells in Tehran are in bad shape and the situation cannot improve with good rains in one or two years.
Surveys of groundwater sources in the plains show that the situation is worsening across the board and creating serious concern among the people conservationists, environmentalists and experts.
The steep decline in groundwater levels is having devastating consequences. Excessive pumping is harming groundwater tables and stopping wells from reaching groundwater. When groundwater is overused, lakes, streams and rivers connected to groundwater also start diminishing.
Land Subsidence
Groundwater overdraft leads to land subsidence as it occurs when there is loss of support below the ground. Destruction of vegetation, increasing possibility of dust storms and higher salt content in groundwater are other grave consequences of overconsumption.
Land subsidence is defined by scientific references as a gradual settling or sudden sinking of the earth's surface owing to subsurface movement of earth materials. Many provinces, including Hamedan, Markazi, Tehran, Qazvin, Isfahan, Fars, Kerman, Sistan-Baluchestan, Hormozgan as well as South and North Khorasan and Khorasan Razavi, among those severely struggling with the phenomenon.
Last year about 170 million cubic meters of treated wastewater was transferred from the South Tehran Wastewater Treatment Complex to farms in the Varamin Plain 40km southeast of the capital.
While 48% of the country’s treated wastewater is used in the farming sector, 45% enters surface waters, less than 0.5% is used by industries and 5% to irrigate urban green spaces. The population covered by the national wastewater network has reached 30 million.
A total of 220 wastewater treatment plants are operating across Iran and total sewage treatment capacity has reached 11 million cubic meters per day.
An additional 32 plants are in different stages of construction and should come on stream within two years.
Over 7.5 billion cubic meters of usable water is produced annually of which 4.3 bcm is wasted. Barely 25% of wastewater is recycled -- a situation that demands improvement, focus and responsibility from those in charge of water affairs.
