Lakhs of people assembled at the beaches -- Dadar, Girgaum, Mahim, Gorai, Marve and others -- to immerse the idols. In Mumbai, the idols are immersed in 448 spots in the western suburbs and 595 in the eastern suburbs. As many as 3,500 public Ganesh idols and 80,000 household ones were immersed today.

``Debris is not a major problem since most idols are made of clay which is soluable. However, since idols are increasingly being made of plaster of Paris, this sometimes creates a problem. But we collect them and deposit them out at sea since they are considered to be holy and cannot be taken anywhere else,'' says S S Bhagwat, BMC's Officeron Special Duty (OSD), whose job includes taking care of the tonnes of nirmalya (flower offerings) churned out every year.

Says environmentalist Debi Goenka, ``The plaster of Paris is not a major problem since it is inert and does not dissolve easily in the sea. Though it takes longer to dissolve than clay eventually it does so after a few days. Paints and other chemicals, which are toxic, cause the greatest problem. This can affect marine life and ecosystem. Other than the sea, the idols are also immersed in fresh water lakes, which pollutes the water used for various purposes.''

Since 1997, the nirmalya from all over the city is collected for vermiculture. Last year, the Somaiya College at Sion was the collection point for the 1,100 tonnes nirmalya. However, this year, it is being collected at all the 24 wards from where they are taken to vermiculture pits in different Area Locality Management schemes.

A serious problem, however, is posed by the plastic bags generated during thisperiod. ``Every ward throws up almost two to three tempos of plastic bags at the end of 10 days. We separate these from the wet material and hand them over to the ragpickers,'' adds Bhagwat. ``We have appealed to people through newspapers and the television to use the facilities provided by the BMC.''

Civic officials say though the administration provides a number of facilities for the revellers, they are not used. Bins or daan petis are positioned near all beaches and ponds but people usually throw the nirmalya and plastic bags all over the place. Says a civic official, ``It is the BMC's job to put them back into the bin. At times, even the plastic bins are stolen. Apart from tankers at every immersion point, we also provide for mobile medical vans and first aid kits to attend to injuries''.

Last year, the BMC provided lighting facilities at 1,935 spots, of which 15 places had generators and 12 had searchlights. More than Rs 73 lakh were spent on these as well as lifeboats.