THIRUVANANTHAPURAM: With the city facing one of the worst summers, the taps in various areas such as Jawahar Nagar is going dry for hours due to the lower water output from Aruvikkara necessitated by higher iron content in the water in the dam.
Though annually, water from Peppara storage dam feeds yellow coloured, iron-laden water to Aruvikkara reservoir for a few days, this summer
the water has continued to be yellow for some weeks now.
“There is an estimated reduction of 5 million litres per day (MLD) from filtration plants because of a higher iron content in water that is purified. We have to add more chemicals to water to clear the iron content. This chokes the filter bed and therefore water output from purification plants are on the lower side. Water with slightly high iron content is consumable but Trivandrumites panic when they notice a yellow colour. But we will not compromise on water quality in the city for quantity,” said a senior official of Kerala Water Authority .
Two filtration plants that generate 84 and 74 MLD respectively now generate less than 82 and 72 MLD respectively. A 5 MLD output means slower replenishment of storage tanks across the city and that leads to water crisis that extends for hours.
The maximum colour hazen unit (hu) permissible in drinking water is 20 whereas the variation in water coming to Aruvikkara is up to 15. However, similar colour variation in tap water that happened the previous year, lasted for five days had caused panic in the city.
Iron content in water happens due to increased decay of plant matter present in and around the dam. Aruvikkara reservoir which has a very small drawable water limit is replenished at least once a day with water from Peppara.
