Bhubaneswar, May 10: Potable water sources of a city that recently emerged high on the nationwide cleanliness chart are not clean at all.
Drinking water for Bhubaneswar is sourced from rivers and canals, but the high level of pollution in these water bodies has become a major health concern.
In its report to the state government, the Odisha State Pollution Control Board has said water of the Gangua and Dayasetu canals and the Daya river was highly polluted.
The Daya starts as a branch of Kuakhai at Saradeipur and flows through Khurda and Puri districts before merging in the Chilika lake. The Gangua emanates from Gadakana and meets Daya near Kanti village on the outskirts of the city.
The city depends on the Mahanadi, Daya and the Kuakhai for its drinking water and the public health engineering organisation fetches and supplies it to households. Eighty per cent of the city's daily demand of drinking water is met from surface sources, while the rest is procured from wells and tube wells.
What has caused the pollution board to sit up and take note is the alarming levels of dissolved oxygen, biochemical oxygen and coliform in water samples procured from the Gangua and Dayasetu canals and the Daya river.
Dissolved oxygen is the amount of gaseous oxygen dissolved in the water and it can be directly absorbed from the atmosphere or from plants. On the other hand, biochemical oxygen demand (BOD) provides an index to assess the effect discharged wastewater will have on the environment. The greater the BOD, the more rapidly oxygen is depleted in the stream. This means less oxygen is available to higher forms of aquatic life.
On the other hand, coliforms are bacteria found in our environment, including the faeces of humans and other animals. The presence of the bacteria hints at the possibility of having disease-causing organisms in drinking water.
According to the findings, the annual average of dissolved oxygen in the Gangua remains at 3.5mg per litre, while it is 6.9mg for biochemical oxygen and the total coliform presence is 100 per cent.
Similarly in the Daya river, the annual average of dissolved oxygen is 4.6mg/litre, while for Dayasetu water the count is 5.1mg/litre. The BOD at these sources is 4.7mg/litre in the Daya river and 4mg/litre in the Dayasetu. The violation of total coliform stands at 100 per cent at both the water bodies.
"We have collected the samples from both the upstream and downstream levels. The findings are horrific. The average dissolved and biochemical oxygen demand should remain below 3mg/litre. The water remains polluted beyond the use of humans or animals. The reason behind the pollution could be the discharge of untreated wastewater to the rivers," said environmental scientist D.K. Behera.
The city has 10 major natural drainage channels. While drain No. 1 opens to the Kuakhai, the remaining nine drainage channels flow into the Gangua, which carries the river water and the pollution load to the Daya. In most places, sewage is discharged into open drains without any treatment and it ultimately flows into the Gangua.
"The high level of pollution stems from the discharge of untreated water into the drainage channels. We are in the process of setting up treatment plants at various places in collaboration with other implementing agencies. We have also decided to enforce strict guidelines for septage management, which would also tackle this growing problem," said mayor Ananta Narayan Jena.
He said implementation of the new septage management guidelines had already been started to ensure that households do not discharge wastewater into open drains, but contain it in soak pits. "We will take care of the septage using cesspool emptier vehicle. We have also identified land at Kalinga Nagar to construct a septage management plant, and the executing agency will begin the work in a month or two," said Jena.
Expressing concern over the quality of water and the slow pace of administrative action, environmentalist AlokMohanty said: "Coliforms are bacteria that are present in the digestive tracts of a living being and found in their wastes. The availability of coliform in water is due to discharge of waste through drains. It could be fatal."