KARACHI: More than 80 per cent of water samples collected from surface and groundwater sources in 14 districts of Sindh for an analysis have shown that water quality in these areas has worsened over the past few months, it emerged on Saturday.

Earlier, 75pc drinking water samples collected from 13 districts were found unfit for human consumption.

The Pakistan Council of Research in Water Resources (PCRWR) had conducted a bacterial and chemical analysis of water samples collected in Karachi, Thatta, Hyderabad, Jamshoro, Tando Mohammad Khan, Tando Allahyar, Badin, Mirpurkhas, Tharparkar, Nawabshah, Khairpur, Sukkur, Shikarpur and Larkana districts.

Sewage found mixed with water supply in many districts

Of the 460 samples, 232 were collected from surface water sources (canals, water supply schemes, pumping stations), 46 from reverse osmosis/filtration plants and three from mixed (ground plus surface water) sources.

Collection spots for water samples included educational institutions, public points and tertiary care hospitals. The results were analysed in the light of World Health Organisation (WHO) and Sindh Environmental Quality Standards on drinking water.

Thar fares better than Karachi

A total of 118 drinking water samples were collected from Karachi, of which 99 samples were collected from surface water sources, including water supply system, filtration plants and pumping stations and 13 samples from reverse osmosis plants.

According to the report, 107 (90.7pc) of the 118 samples were found unsafe for human consumption, which means only 11 samples were suitable for drinking.

Around 104 samples had bacterial contamination. Of them, 40pc samples had faecal contamination. High turbidity and higher levels of sulphate, nitrate-nitrogen, total hardness, calcium, magnesium and potassium were also found in water.

In comparison, of the 28 samples collected from Tharparkar district, 10 samples (35.7pc) were found unfit for human consumption.

“Most samples were found safe from bacteriological contamination when collected directly from the reverse osmosis plant. Samples collected from community storage tanks/ponds, however, were found severely contaminated with coliforms and E.coli,” the report says.

The study team observed the same situation at the Misri Shah reverse osmosis plant in Mithi and another plant installed in Islamkot.

The water quality situation was found poorer in Larkana district where only three of 25 samples were found fit for human consumption.

Sixteen samples were collected from Thatta district, of which 14 were found unfit for human consumption. Out of a total of 40 samples collected in Hyderabad, 35 were found unfit for human consumption.

Tando Allahyar and Jamshoro districts had only one sample fit for human consumption out of 11 and 30 samples collected, respectively. Similar results were reported from Tando Mohammad Khan district where 17 of 20 samples were found contaminated.

In Badin district, 29 of 36 samples were found unfit for human consumption. Samples collected from underground water sources had a high content of salts as well as bacterial contamination whereas surface water had high turbidity with the presence of E.coli and coliform, indicating mixing of sewage with supply line water. Eighteen of 20 samples were found unsafe in Mirpurkhas. Underground water was also found contaminated with sewage in the district.

Overall data of Nawabshah district shows that 11 of 26 samples were found safe for drinking purposes. In comparison, however, Khairpur had only eight samples out of 28 that were safe.

Five of 30 samples collected from Sukkur district were found safe. Severe bacterial contamination was detected in half of the samples. Shikarpur had seven of 32 samples safe.

The PCRWR team collected 87 samples from 71 hospitals in 14 districts and found 68 (78pc) unfit for human consumption.

“Overall analytical data shows that out of 460 water samples, 384 (83.5pc) were found unsafe and 76 (16.5pc) safe,” the study concludes.

Reasons for unsafe results were improper or the absence of filtration and chlorination, mixing of sewage with supply line water and silting of pumping stations and water tanks.

Published in Dawn, July 16th, 2017