A team of four from Jharkhand State Pollution Control Board (JSPCB) inspected the Getalsud Dam on Sunday, June 24, 2018, because hundreds of dead fish floated to the surface on Saturday.
It was discovered that the water, normally a pH of 7, was extremely alkaline at 12.5 pH.
Carbonate ions, from compounds like calcium and magnesium carbonate increases the alkalinity of the water and that is detrimental to aquatic life. However, it is subject to evaluation whether untreated chemicals from a private steel wire manufacturing plan is part of the high pH issue. The District Fisheries Department will be serving notice to the plant, according to Usha Martin.
As many as 300 fish were removed from the surface of the water, in Angara block, 30 km from the city. A member of the pollution monitor said that the level of dissolved oxygen was not the problem at the Getalsud Dam.
According to fishermen, “the water is being polluted by discharge of the intreated effluents from the steel wire manufacturing unit. We tested the water at the outfall of the unit. It was highly alkaline with a pH value of 12.5. A pH range of 6.5 to 9 is more acceptable,” said Martin.
Extreme pH can kill adult fish and invertebrates directly, according to experts. The severe alkalinity can also damage developing juvenile fish. The water strips the fish of their slimy coats and chaps the skin. If the pH of the freshwater rises above 9.6, the effects on the fish include damage to the gills, eyes or skin, the inability to dispose of metabolic waste, and death.
High pH also increases the toxicity of other substances. For instance, ammonia is 10 times more severe at a pH of 8, than at 7. It is directly dangerous to aquatic life when it appears in alkaline conditions. Low concentrations of ammonia are generally permitted for discharge.
The manager of Ranchi fisheries, Manoj Thakur, said that most of the dead fish were Indian carps. They cannot survive in extremely acidic or alkaline conditions. “The fish most probably succumbed to some descaling disease (because of the high alkalinity). We are going to contact the water resources department tomorrow (Monday). The manufacturing unit will be served a notice.”
Thakur spoke on remedial measures, saying there is no easy way to treat a reservoir that spans over 700 acres. Using chemical treatments to balance the pH is possible in small catchment areas. Another option is to rescue the affected aquatic species. They can be dipped in a special solution and then released back into the water. However, this technique is not feasible.
Rajeev Lochan Bakshi, the member-secretary of the JSPCB, said they had a zero-tolerance policy toward pollution. If the industrial unit is causing pollution the agency will take action. If necessary, the plant will be shut down.
Nearly 5,000 people rely on fishing at Getalsud as their single source of livelihood. “We are asking people not to take the dead fish home for cooking because they might be poisonous for consumption. We have urged the fisheries department to collect fish samples for tests.”
By Jeanette Smith
The Telegraph: Alkaline water suspected killer
Image by Skmishraindia Courtesy of Wikimedia Commons - Public Domain License