Discharges from Manchhar Lake raise levels of impurities in Indus River waters
HYDERABAD: The Water and Sanitation Agency’s test reports on the quality of Indus River water have indicated increase in the values of total dissolved solids (TDS) apparently due to discharges from Manchhar Lake into the river.
Wasa lifts water from the river and supplies it to Hyderabad city after purifying it at its lagoons.
The lake’s discharges through Aral Wah had reportedly been stopped on Tuesday on the advice of water technologist Dr Ahsan Siddiqui following Wasa’s complaints, causing water shortage in Latifabad and other parts of the city.
In view of the emerging situation, Hyderabad deputy commissioner Tariq Qureshi sent a letter to secretary of irrigation on Tuesday to ensure release of freshwater for Wasa to mitigate effects of “toxic water spillage” into its lagoons.
Wasa lifts water from up and downstream Kotri barrage for its two large lagoons in Karan Khan Shoro village near the barrage from where water travels to new and old filtration plants located off Jamshoro road.
“Values of TDS increased at [30MGD] new filtration plant of Wasa over last couple of days apparently due to releases of water from Manchhar into the river,” said acting Wasa managing director, Zishan Malik.
According to the DC’s March 26 letter seen by Dawn, TDS limits started increasing from March 20 and jumped from 500mg/l to 720mg/l whereas Mr Malik said the TDS level had risen to 770mg/l on Tuesday and dropped to 730mg/l on Wednesday morning.
“When it reaches 800mg/l we stop filling our lagoons because at this level water develops a different taste and people find it unfit for drinking,” he said.
The DC informed the secretary in his March 26 letter that Sindh High Court’s Hyderabad circuit bench had expressed concern over lack of provision of clean drinking water to Johi, Khairpur Nathan Shah and Mehar talukas in Dadu district.
Sugar mills waste
Water technologist Dr Ahsan Siddiqui, who monitored quality of Manchhar water before it was released into the river and ensured required dilution formula, said the WHO recommended 1000mg/l TDs was within permissible limits and the TDS was recorded at 548mg/l as per Tuesday’s finding at A.D Baloch point where it admixed the river water. “We have stopped releasing water from the lake following Wasa’s test reports,” said Siddiqui.
He attributed current increase in TDS value at Wasa’s laboratory to releases of wastewater from Matiari sugar mills into the river. It had been reported time and again that the mills’ waste went into the river and Wasa needed to keep an eye on it, he said.
“Values get disturbed due to the mills’ waste that is mixing with river water. We release 200-300 cusecs of lake’s water into the river. The lake’s level is 110.6RL and we have to maintain it at 107RL or 108RL by July to avoid threat to the lake’s safety in rains,” he remarked.
Water shortage
Drinking water shortage was being reported in parts of Latifabad and city for multiple reasons. Wasa’s three pumping stations located near Unit-4 river dyke downstream Kotri barrage were not fully functional.
One of the pumping stations showed zero working due to heavy deposits of silt. The three pumping stations cater to the needs of unit numbers 8, 4, 10, 11 and also feed unit-4 6MGD filtration plant.
Similarly, Effendi Town, Vishan Nagar, Tando Agha, Islamabad etc were not getting water due to load-shedding.
According to the Wasa MD, since Hala Naka facility is not getting electricity from Miani forests feeder, it is causing shortage. “We need 10 hours uninterrupted power from 6 am to 8 pm and we made such a request to Hesco but in vain,” he said.
Testing and monitoring of the lake had started following 2004 water crisis which had led to deaths of around 40-50 persons in Hyderabad and adjoining districts from consumption of contaminated river water and the lake’s toxic water was released into the river without any dilution formula. The matter landed in Sindh High Court and then Supreme Court.
Published in Dawn, March 29th, 2024