The grades on the city’s annual environmental report card are slipping with drinking water getting more contaminated than last year, decibel levels shooting up and air showing high level of pollutants in some areas.

These are the finding of the Environmental Status Report (ESR) to be released by the BMC next month. The exhaustive report was prepared with data compiled from different departments of the BMC, state and Central governments, the Maharashtra Pollution Control Board and the National Environmental Engineering Research Institute (NEERI).

Water contamination for the year 2007-08 has been recorded at 12.47 per cent as against 9.05 per cent last year. A total of 37,939 samples were tested for end user water quality over this period. The findings show that owing to the ingress of foul water through leaky pipelines, unfit samples have increased by 37 per cent last year.

“Measures undertaken by the BMC such as pipeline replacements, fixing of leakages and removal of slums along pipelines will yield results in the long term,” said RA Rajeev, additional municipal commissioner in charge of environment.

In each of the 24 wards, water contamination levels are higher than last year. For instance, in 2006-07 only C ward (Marine Lines) recorded a high contamination level of 15 per cent . This year, C, A (Fort, Colaba), E (Byculla), L (Kurla, Kalina) and S (Bhandup) wards have a high degree of water contamination from 15 per cent to 17 per cent. Only one ward, P North (Malad) has recorded a contamination level less than 6 pc, down from last year’s seven wards.

The report also states that all over Mumbai, noise levels have not only exceeded Central Pollution Control Board (CPCB) standards but are also higher than last year.

As far as the quality of ambient air is concerned, the report points out that of the six air monitoring stations, four have recorded heavy pollution levels — Maravali (Chembur), Andheri, Bhandup and Khar.

While levels of sulphur dioxide, nitrogen dioxide and lead are within limits, ammonia has exceeded prescribed standards at Maravali. Like every year, levels of SPM have exceeded standards at all sites except Borivali.

The report also notes that traffic density at peak hours is so high that vehicles move at 5 km to 8 km per hour and ambulances are unable to move during emergencies at strategic places like Sion, Bandra and Dadar. The number of vehicles plying on the city’s streets have increased by 6 pc over last year and with 384 vehicles being added every day, the report predicts that it is only going to get worse.