EghtesadOnline: The quality of tap water in Tehran differs from one district to another, managing director of Tehran Regional Water Company said.
“So long as South Wastewater Treatment Plant in the capital is not developed, at least 30% of tap water in these regions should be supplied from underground resources that have lower quality compared to dam water,” Seyed Hassan Razavi was quoted as saying by ILNA.
Unlike the southern end of the city, tap water in uptown Tehran is not mixed with underground water and comes (mostly) from surface waters (dams) and has better quality, Financial Tribune quoted him as saying.
South Wastewater Treatment Plant in the ancient city of Rey is the biggest of its kind in the country. Six units of the plant are in operation, but due to population density in southern areas there is need for two more units.
The functioning units now cover 3.15 million people and treat 246 million cubic meters of wastewater per annum. With the two new units the plant will offer service to 4.2 million people.
He concurred that wells are more vulnerable to nitrate contamination than dams. Nitrate contamination can occur particularly in shallow wells, dug wells with casing that are not watertight and wells with damaged leaking casing or fittings. Too much nitrate in potable water poses risk to infants less than six months oold.
Tehran water quality was better in the past due to greater use of surface water and dams than well water. “However, at present (regardless of quality) the water is safe.”
Work is underway at the Firouz Bahram Wastewater Treatment Plant in west Tehran and is the second largest in the country after the South Wastewater Treatment Plant, he added. Firouz Bahram plant is set to come online by 2021 and will be used by 2.8 million people.
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 annually produced, of which 4.3 bcm is wasted. Less than 25% of wastewater is recycled -- a situation that demands focus and responsibility from those in charge of water affairs.
Tehran dams, namely Taleqan, Latyan, Mamlou, Karaj and Lar together can hold 1.93 bcm of water.