Sixty wastewater plants are under construction in the country and should be operational by next August, deputy energy minister for water affairs said.
Work is in progress and in four decades the number of plants has increased 40 times, IRNA reported Ghasem Taghizadeh Khamesi as saying
“There were four sewage treatment plants in the late 1970s. Now it is 235 and 65 were built in the past seven years,” he said.
Referring to the sewerage system in the capital city, he said: “In Tehran 7,000 kilometers of wastewater pipelines were laid and covers 85% of its population”.
“Efforts are being made to complete Tehran's largest wastewater treatment plant in the south of the city with a capacity of 529 cubic meters of sewage per day by next March.”
The treatment plant will cover 2.8 million people in Tehran and part of the output will be used by the Tehran Municipality for green spaces, Taqizadeh Khamesi said.
Approximately 7.5 billion cubic meters of usable water is produced annually of which 4.3 bcm is wasted and less than 25% is recycled.
While 48% of the 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 is 30 million.
There are 222 wastewater treatment plants in Iran and total sewage treatment capacity has surpassed 11 million cubic meters a day. Over 66,000 km of wastewater pipelines have been laid across the country and 300 cities are connected to the rapidly expanding system.
The World Health Organization has said that more than two billion people worldwide do not have access to sewage systems.
Mainly in low-income areas of cities and towns within developing countries, a large proportion of wastewater is discharged directly into the closest surface water drain or informal drainage channel, sometime without or with very little treatment.
In addition to household effluent and human waste, urban-based hospitals and industries such as small-scale mining and motor garages, often dump highly toxic chemicals and medical waste into the wastewater system.
Insufficient treatment of wastewater and fecal sludge spreads disease and is a driver of antimicrobial resistance. Demand for wastewater as a reliable source of water and nutrients for agriculture is growing in response to population growth, urbanization, increasing water scarcity and the effects of climate change.
Safe sanitation systems are fundamental to protect public health. WHO is leading efforts to monitor the global the burden of sanitation-related disease and access to safely managed sanitation and wastewater treatment and factors that enable or hinder progress under the sustainable development agenda.
Given the limited fresh water resources in many countries (including Iran), people are forced to use the precious resource prudently by adopting a variety of ways, one of which is tapping into unconventional sources like greywater.
This method, however, remains a far cry in Iran.
“Using greywater can help reduce extraction of underground water by up to 40%,” Khamesi said, adding that 80% of urban wastewater can be treated and reused.
Greywater is defined as any domestic wastewater produced, excluding sewage. The main difference between greywater and sewage (blackwater) is the organic loading.
