New Delhi, Jan 25 (PTI) Delhi Deputy Chief Minister Manish Sisodia on Wednesday approved a project to provide sewer line connections in three villages and 29 unauthorised colonies of Wazirabad, Bhalswa and Swaroop Nagar that will help reduce the Yamuna's pollution load.
Around five lakh people will benefit from the Rs 77-crore project, according to a statement.
The 22-kilometre stretch of the Yamuna between Wazirabad and Okhla in Delhi, which is less than 2 per cent of the river's length, accounts for around 80 per cent of its pollution load.
Untapped wastewater from unauthorised colonies and jhuggi-jhopri clusters and poor quality of treated wastewater discharged from sewage treatment plants (STPs) and common effluent treatment plants (CETPs) is the main reason behind high levels of pollution in the river.
There are a total 1,799 unauthorised colonies in Delhi. Of these, 725 have been connected to the sewer network, while work is underway in 573 others.
Sewage from unauthorised colonies not connected to the sewer network flows directly into the Yamuna, increasing its pollution load.
The Delhi government has promised to clean the Yamuna to bathing standards by February 2025.
The river can be considered fit for bathing if biological oxygen demand (BOD) is less than 3 milligram per litre and dissolved oxygen is greater than 5 milligram per litre.
BOD, an important parameter for assessing water quality, is the amount of oxygen required by aerobic microorganisms to decompose organic material present in a water body. A BOD level less than 3 milligram per litre is considered good. PTI GVS SZM