BOD level in treated water found above permissible limit
While the councillors and city residents are raising questions on the quality of tertiary-treated water, the Chandigarh Pollution Control Committee has detected various shortcomings in sewage treatment plants (STPs) of the UT Administration and the Municipal Corporation.
A CPCC team recently visited STPs at Diggian Mohali, 3 BRD, Raipur Kalan, Raipur Khurd and Dhanas and found some shortcomings. The committee has now sought reply from the UT Administration and the MC on these shortcomings.
Sources revealed that the team found that many of these plants had been releasing treated water with much higher bio-chemical oxygen demand (BOD) than the permissible level of the maximum 30 mg/litre.
The BOD is the quantity of dissolved oxygen needed by aerobic biological organisms in a water body to break down organic material. High BOD is an indicator of the level of organic pollution of water.
Sources added that sludge was not treated with chemicals before it was being disposed into drains.
On the tertiary-treated water project, the civic body has already spent over Rs 15 crore. Besides, the MC is also spending Rs 1 crore every year on the operation and maintenance of three STPs. Expenditure apart, the quality of the tertiary-treated water is poor.
New CPCB norms to reduce BOD level
- Last year, the Central Pollution Control Board (CPCB) had notified stringent norms for STPs so that their discharge matches global parameters on water quality. As per the new norms, the BOD level has to be reduced from 30 mg/litre to 10 mg/litre. The CPCB had given two-year time to states and UTs to prepare an action plan to adopt the new norms. However, sources revealed that the MC was yet to prepare its action plan.
Few takers for tertiary-treated water connections
- The MC has spent over Rs 15 crore on the project to supply tertiary-treated water to houses measuring one kanal and above in various sectors and green belts. However, the MC has found a few takers among residents for new connections. Though there are around 6,000 such houses, owners of only 700 houses have applied for these connections during the past four years.