There has been a significant deterioration in the quality of air during seven days prior to Deepavali and seven days after the festival, says the Annual Environment Survey Report 2018.
The report, which was released by Chief Minister V. Narayanasamy a few days ago, said monitoring of air quality conducted at Balaji Nagar, Reddiarpalayam and Bharathi Street, Nainarmandapam pointed towards high presence of particulate matter, which is a mixture of solids and liquids in the air.
The concentration of particulate matter less than or equal to 10 microns (PM10) were higher than the prescribed standard limit of 100 per cubic metre (ug/m3). Nickel and arsenic were present in PM10 at both the locations, the report said.
The concentration of sulphur was found higher on the day of Deepavali for which standards were yet to be proposed. Deterioration in air quality was noticed during Bhogi festival also, the report added.
Water quality
On the section on water quality, the report said the biochemical oxygen demand (BOD) of water collected from the Chunnambar, Kanaganeri lake and Oussudu were slightly higher than the primary water quality criteria of 3 mg/l. While the BOD in Chunnambar was 5 mg/l and Kanaganeri 6 mg/l, the demand level was 4.2 mg/l in Ousssudu.
The BOD indicate presence of putrescible organic matter.
A high level of BOD indicated contamination of water, said an official with the Department of Science, Technology and Environment, which prepared the report.
The report pointed towards high presence of total dissoluble solids in water collected from Uruvaiyar borewell. The turbidity in Eachengadu borewell was 49.2 nephelometric turbidity unit (NTU) while the permissible limit was 5 NTU.
On the solid waste management front, the report said solid waste management possessed great challenge to the administration. In spite of continuous efforts source segregation could not be placed in the system.
As per the report, on an average day the two municipalities together produced 425 tonnes a day.
The Local Administration Department in April has constituted a special task force to finalise the scientific way of disposal of solid waste in the Union Territory, the report said.