Around 25% of water samples collected from wells in the flood-hit regions of Ernakulam have been found highly contaminated in a study conducted by the School of Environmental Studies at Cochin University of Science and Technology (Cusat).
Worst-hit regions
The wells are located in the worst-hit regions of Aluva, North Paravur, Kalamassery, Manjummel, Angamaly, Kalady, Kanjoor, and Perumbavoor.
“Of the 172 wells from which samples were taken, 43 were found contaminated with faecal coliform. The most probable number (MPN) of coliform count per 100 ml in these samples was above 1,100,” said V. Sivanandan Achari, Director of the School of Environmental Studies, Cusat.
Dr. Achari said that the total coliform count should be 50 or less per 100 ml in water found fit for consumption, according to the Central Pollution Control Board (CPCB) norms.
“This is part of the criteria for Class A of water [drinking water source without conventional treatment but after disinfection],” he said.
Of the 172 wells from which samples were collected, three wells were found having water with a total coliform organism count higher than 50 MPN and below 1,100 in 100 ml, while nine wells had coliform content in the range of 1,100. Around 34.3% of wells had coliform presence slightly above 50 MPN in 100 ml. Water drawn from these wells could be used after continuous chlorination for three to four days. It also has to be boiled before use. The total coliform count in water collected from 47 wells was below 50, while there was no coliform presence in 11 wells.
Free of cost
Dr. Achari said that the water samples were tested free of cost as part of an extension activity of the school under the rehabilitation programme for the flood-affected people launched by the varsity. “We usually submit our report to the flood-hit families, whose wells were polluted, stating that the water is unfit for consumption,” he said.
Researchers at the school have already received around 500 samples from the flood-hit regions in Ernakulam. The physical and chemical parameters of 459 samples have been ascertained as on Friday. Of this, the team has finished the complete analysis (including microbiological analysis) for 172 samples.
Dr. Achari said that leakage from septic tanks had resulted in the contamination of well water with faecal coliform.
It could also have been caused by the presence of slaughter waste dumping sites, chemical factories, and chemical storage facilities near drinking water sources.
Samples could be collected after a week to confirm whether the total coliform presence has come to 50 or less in 100 ml, they added.
Extension of service
Dr. Achari said that the water testing facility at the school could be used for carrying out sample analysis of drinking water from drinking water sources across the State. “As of now, we have reached full capacity. We could extend our services with additional government and outside support,” he added.