Biological Oxygen Demand Levels in River Ganga

2019 ias preliminary exam test series

In Namami Gange project total number of 155 projects for various activities such as sewage infrastructure, river front development, ghat and crematoria, ghat cleaning, rural sanitation etc. has been sanctioned.

Out of 155 projects 39 numbers of projects have been completed so far.

Cleaning of river Ganga is being carried out through various activities including treatment of municipal sewage, treatment of industrial effluent, river surface cleaning, rural sanitation, afforestation and biodiversity etc.

The municipal sewage being generated in cities on the banks of Ganga is being managed by a mix of Interception & Diversion projects, sewerage network and sewage treatment plant (STP) projects.

The four stretches of river Ganga where Biological Oxygen Demand (BOD) levels are more than permissible limits, as monitored by Central Pollution Control Board (CPCB) is given in table below:

State Stretch Identified Length of Stretch (Km) BOD range/ max value (mg/l)
Uttarakhand Haridwar to Sultanpur Adampur 10 4.2-5.8
Uttar Pradesh Kannauj to Varanasi 450 3.8-16.9
Bihar Buxar to Bhagalpur 40 7.8-27
West Bengal Tribeni to Diamond Harbour 50 3.1-5.8

In other stretches, BOD levels are within permissible limits i.e. =<3 mg/l. However, as per monitoring reports of CPCB, entire stretch of river Ganga has high levels of faecal coliform against the prescribed limits.

Biochemical oxygen demand (BOD, also called biological oxygen demand) is the amount of dissolved oxygen needed (i.e., demanded) by aerobic biological organisms to break down organic material present in a given water sample at certain temperature over a specific time period.

The BOD value is most commonly expressed in milligrams of oxygen consumed per litre of sample during 5 days of incubation at 20 °C and is often used as a surrogate of the degree of organic pollution of water.

BOD can be used as a gauge of the effectiveness of wastewater treatment plants. It is listed as a conventional pollutant.

BOD is similar in function to chemical oxygen demand (COD), in that both measure the amount of organic compounds in water. However, COD is less specific, since it measures everything that can be chemically oxidized, rather than just levels of biodegradable organic matter.

The detailed status of break-up of funds spent/released to the states from Financial Year 2014-15 to 2017-18 till 30.06.2017 are given below.                        Rs. in crores

States 2014-15 2015-16 2016-17 2017-18 Grand Total
Bihar   120.23 82.03 0.20 202.46
Jharkhand 0.97 27.83 46.18 2.47 77.45
UP 74.58 147.58 587.17 38.22 847.55
Uttarakhand 4.26 30.26 30.66 16.26 81.44
West Bengal 73.85 185.79 114.25 0.11 374.00
Haryana 30.00 52.73 0.00 82.73
Delhi   4.96 2.17 2.66 9.79

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