Manganese content way above permissible levels
TEAM HERALD
[email protected]
PANJIM: High manganese content has been detected in the Selaulim water reservoir once again, but for the first time it has surfaced in the month of March. Normally, the increase in manganese content happens in July and November, where it rises above safe limits.
Manganese content (which comes from mining dumps nearby) from 0 .1 mg per litre is permissible and upto 0.6 mg/litre is manageable. Higher levels could be hazardous to health and cause water shortages due to extra time, effort and expenditure required during the filtration process to make the water safe.
Chief Minister Manohar Parrikar while admitting that the manganese content in the dam waters has been found to be as high as 0.7 milligram per million cubic litres of water said Mormugao and Salcete talukas could be heading towards restricted water supply for the next couple of days as a result of this development.
Engineers monitoring the manganese levels on an hourly basis said that on Thursday morning the levels were 1.5 mg/litre while by around 3 pm it had reduced to 1.2 mg/litre. The increase has been noticed from March 15, but had also taken place in January and February, they disclosed.
PWD engineer S R Paranjpe said “Usually in this period there is no increase. But this year it had increased,” he said, adding that they are expecting it to reduce and were trying to bring things back under control.
The Selaulim dam is the biggest one on Zuari river and supplies water to whole of South Goa and parts of North Goa, with storage capacity of 234.36 million cubic metres. The plant normally treats 180-185 mld of water.
“When water for irrigation is released there is an upswelling which results in manganese levels rising,” Parrikar explained adding that engineers are working overtime to ensure that the manganese content in the water is lowered. “We expect the problem to be solved in two days. In the meantime, there will be water shortage in Mormugao and Salcete talukas,” he added.
This is for the second time in last eight months, when the manganese content in the reservoir has gone up. In July last year, the manganese content had gone up six fold to 3.5 mg. Experts say that the manganese in the rejects stored as mining dumps and the submerged mines have led to the manganese entering the reservoir..
Goa State Pollution Control Board (GSPCB) Chairman Jose Manuel Noronha said the board would be be collecting water samples to check the manganese content as part of our routine exercise,” he said.
The chief minister who is also the mines minister in a written reply to an unstarred question said “There are altogether 13 mining leases located within 500 metres from this reservoir, pointing out that three of these leases are located within a 200-metre radius from the Selaulim reservoir.
PWD Minister Ramakrishna Dhavalikar had on July 12, 2012 told the House that because of the high manganese content in raw water and its hazardous effect on the health of consumers, the government had directed authorities to remove all mining dumps existing in the area, on a priority basis.
