The Times of India                  10.04.2013

HYDERABAD: The Sewage Treatment Plants (STP) installed near 14 lakes of the city are not good enough to get rid of pollutants and most of the 'treated water' cannot sustain aquatic life and is poisonous enough to kill thirsty domestic animals.

A latest report by the Pollution Control Board (PCB) on STPs revealed that water in lakes still contain pollutants much higher than the permissible limits even after treatment. Readings of the treated water of STP at Khairatabad and at the Hussainsagar lake, between June, 2012 and February 2013, show the presence of high levels of BOD (Biological Oxygen Demand) and COD (Chemical Oxygen Demand) in the treated water.

The permissible levels of BOD are not more than 30 ms/l and that of COD is 250 ms/l. However, BOD levels were found to be as high as 116 ms/l and those of COD were found to be touching 284 ms/l in some of the monthly readings, which means the water still cannot support aquatic life.

Another analysis conducted at the Amberpet STP in February this year showed that the pH value of the treated water was 9.4, whereas the permissible range is between 5.5 and 9, which means the water is alkaline in nature. "The high levels of COD and BOD in Hussainsagar prove that it is highly contaminated and not fit for anything. Not only is this water poisonous to aquatic animals but also a great threat to domestic animals like cattle and dogs which may quench their thirst with the lake water," said K Babu Rao, an environmentalist and scientist.

The high alkaline levels at Amberpet STP is also pose a grave threat to the people of the surrounding areas as the Musi lake water may percolate into ground water, environmentalists say. "The usage of highly alkaline water even for domestic purpose may result in a various health conditions including skin infections to respiratory disorders," Babu Rao added.

Even in the past, environmentalists criticized about the low capacity of these STPs which render it ineffective in completely treating waste water. The existing capacities of the STPs range from 4 mld to 339 mld.

A senior official of pollution board said that only a small part of waste water is being treated at the STPs whereas most of it is getting routed back into the lake. "These STPs have low capacity and hence, it is not possible to store and hold large volumes of waste water," he said on condition of anonymity.

Power disruptions are also adding to the problem with the STPs not functioning for at least three hours everyday, thanks to the power cuts. "The administration has absolutely no back-up mechanism in place to ensure that STPs function continuously," said Thakur Rajkumar, covenor, SOUL (Save Our Urban Lakes). "These plants cannot run with generators or inverters since they need a lot of power and the result is untreated water keeps flowing into the lakes for hours together. If this goes on throughout summer, then the condition of lakes will only worsen," he added.