Pollution from thermal power plant
Thermal power plants contribute to 13% of air pollution. The main pollutants are stack emissions; fly ash generations and fugitive emission in coal handling. All thee thermal power plants Delhi need better use of their emission control devices and the fly ash that they generate.
Industrial air pollution
The air pollution generated from industrial activity in Delhi is about 12% of total air pollution. More than 1,300 industrial units that were not allowed to operate under the MPD - 2001 norms have been closed.
The 1991 reports by the National Environmental Engineering Research Institute (NEERI), Nagpur documents the amount of pollution that is contributed by different sectors in Delhi:
In relative terms, the quantum industrial air pollution has decreased over the years. However, vehicular pollution has increased rapidly. The drop in share of domestic air pollution is due to the increased number of LPG connections in Delhi, which have replaced other forms of fuel.
Noise levels in Delhi exceed permissible levels in all areas except industrial areas according to a study by the Delhi Pollution Control Committee. Since noise is measured on a logarithmic scale, an increase of every 3-4 dBA has twice the effect on humans. Diesels generating sets and vehicles, particularly auto rickshaws, have been identified as major sources of noise pollution of Delhi.
Water pollution (surface water pollution)
Around 1393 mld of sewerage finds its way into river Yamuna through 19 major drains. Out falling into the river carrying 218 mls which includes 48 mgd of industrial effluent. BOD content of this water is 587 mld in all the 5 sewerage zones of Delhi. 64% of total BOD is from domestic sources. 10-15% of nutrients added to the soils through fertilizers eventually find their surface water system.
The highest load occurs from the NCT Delhi (about 152 MT/day of BOD load) as compared to the loads of other cities which vary from 1 mt/day) as per Yamuna Action Plan. Everyday about 1880 mld of waste water is discharge into the river from Delhi through 18 drains. More than 95% waster water in Delhi is drained by 5 drains viz. Nazafgarh, Sen Nursing home, and power house drain.
Ground water pollution
There is progressive increase in bicarbonate sulphate and chloride ions with increase in salinity, predominant in ground water from areas with high salinity at deeper levels to the tine of EC 10,00 micro siemens/cm. North western and south western part of NCT have saline water at all levels. The NCT of Delhi has 428.07 mcm utilizable. Ground water resources and balance available is 140.79.
Fluoride concentration is more than 1.5 mg/litre which is the permissible concentration, nitrate concentration is more than 45 mg/litre and at some places it is even more than 100mg/litre.
Lead emission in Delhi and other metros
| Delhi |
Gasoline
consumption(mt) |
Lead content(gm/I) |
Total lead emission
(mt) |
| 94-95 |
65,799 |
0.56 |
86 |
| Post '95 |
340,663 |
0.15 |
---- |
Domestic waste water pollution
The increase in population has resulted in a corresponding increase in the volume of domestic waste water that is generated. Sewage treatment capacity is about 344 MGD at present against 470 MGD wastewater that is generated each day in Delhi. The sewage treatment capacity is not fully utilized due to malfunctioning of the trunk sewer system.
Industrial wastewater
The industrial waste water generated in Delhi is about 70 MGD. Although some industrial units have provided facilities to treat wastewater, most small scale industries do not have such facilities.
The 48 km stretch of the Yamuna River in Delhi is heavily polluted by domestic and industrial wastewater. The river water upstream of Wazirabad is fit for drinking after it has been treated, but after the confluence of Najafgarh drain and 18 other major drains, the water quality becomes heavily degraded and is unfit even for animal consumption and irrigation.
There are 28 industrial areas in Delhi. Most of the small and tiny industries do not have individual facilities to treat liquid waste. The Supreme Court has ordered that 15 common Effluent Treatment Plants (CETPs) be constructed. Action has been taken against 2,300 industrial units in Delhi so far (January 2000) and is continuing to cover all such water polluting units.
Pollution by sector of origin
| |
70-71 |
80-81 |
90-91 |
99-00 |
00-01 |
Industrial
(incl. thermal) |
56% |
40% |
29% |
25% |
20% |
| Vehicular |
23% |
42% |
63% |
70% |
72% |
| Domestic |
21% |
18% |
8% |
5% |
8% |