KARACHI: A majority of water samples collected from surface and underground sources in 13 districts of Sindh, including all six Karachi districts, by a federal institution in a recent survey have been found to be unfit for human consumption, it emerged on Saturday.
The Pakistan Council of Research in Water Resources (PCRWR) collected 300 water samples from Sukkur, Larkana, Shikarpur, Tando Mohammad Khan, Badin, Tharparkar, Hyderabad and Karachi’s six districts — East, West, South, Central, Malir and Korangi — and tested the same for a detailed physiochemical and bacterial analysis. Later, the findings were compared with the World Health Organisation and the National Environmental Quality Standards on safe drinking water.
“We have been regularly carrying out analysis of water samples for the past many years in Sindh and I can say with authority that there hasn’t been any improvement in the quality of water being supplied to the various parts of the province,” said Dr Ghulam Murtaza of the PCRWR.
According to him, the poor quality of water being supplied to Karachi, Hyderabad and Sukkur — the three districts whose water quality has continuously been monitored since 2005 — can be gauged from the fact that the number of unsafe water samples have usually ranged between 80 and 90 per cent.
Around 80pc of potable water samples in Karachi have bacterial contamination
“Improvement [in the quality of water] can only come when the factors contaminating water are addressed. They include mixing of sewage in the drinking water supply line, lack of treatment [where source of contamination is high levels of subsoil minerals] and filter plants [to disinfect and reduce turbidity], improper chlorination [in places where filter plants exist] and contamination by industrial and domestic sewage at the drinking water source [for instance Keenjhar lake supplying water to Karachi],” Dr Murtaza explained.
In the recent analysis, over 70 per cent of water samples in Sindh were found unfit for human consumption, he added.
The sampling, he said, was focused on urban areas, which largely did not have arsenic contamination in their water supply.
“This issue has been found in the groundwater of Khairpur, Tando Mohammad Khan, Tando Allah Yar, Gambat, Thatta, Jamshoro and Naushehro Feroz in previous studies,” he said.
Around 80pc samples had bacterial contamination in Karachi. Of them, 30pc samples had faecal contamination. The samples, more than half, also showed elevated turbidity levels and high concentration of total dissolved solids (TDS), hardness and sulphate, sodium and chloride and were unfit for human consumption.
Only 20pc samples were found safe in Karachi.
The water samples collected from Hyderabad, Larkana and Sukkur showed similar results; more than 80pc samples were found unfit for human consumption on account of bacterial contamination, whereas many samples had TDS, sulphate, hardness, calcium, chloride and iron content beyond permissible limits.
In case of Tando Mohammad Khan and Badin districts, more than half of the collected samples were found unsafe due to high TDS and bacterial contamination, whereas many were found with hardness beyond permissible limits and had elevated levels of calcium, magnesium, sodium, sulphate, chloride and iron content.
Between 50pc and 60pc of water samples were found unsafe due to bacterial contamination in Tando Mohammad Khan and Badin. Thirty per cent to 40pc samples in these districts were found safe.
More than half of the water samples collected from reverse osmosis plants installed in Tharparkar were found unsafe due to bacterial contamination and high TDS.
A significant number of samples were unsafe on account of high sodium and chloride.
According to experts at the PCRWR, these results were more or less similar to those published last year in a report titled Multiple Indicator Cluster Survey.
In 2014, the PCRWR conducted the water analysis of five districts of Sindh (which are not included in the present analysis) — Jacobabad, Kashmore-Kandhkot, Shikarpur, Khairpur and Ghotki. Out of 1,661 samples collected from subsoil sources of these districts, 970 (58pc) were found unsafe.
The major contaminants were turbidity, bacterial contamination, TDS, hardness, calcium, sodium, potassium, chloride, sulphate, fluoride, nitrate, iron, etc.
Published in Dawn, March 5th, 2017
For more live updates, follow Dawn.com's official news Instagram account @dawn.today