Why do municipality workers burn the garbage they collect?

I often notice that the municipality workers who clean the roads burn the garbage they collect by the road side. This act of burning emanates heavy smoke and leads to pollution. Today, I stopped them in between and asked them to not burn the garbage and dispose it off in the dumping station. All they said to me was ' Nee Pani nuvvu chusko sir, na Pani nenu cheskunta' I'm not offended or angered but I'm really surprised by the lack of awareness they have. I'm really curious to know the reason for burning the garbage and not disposing it off in a proper manner. Sigh!!