As announced in this news item http://www.channelnewsasia.com/stori...269297/1/.html , this abandoned quarry which is now totally unproductive and filled with things like pitcher plants, jungle fowl, lush vegetation and birds will soon be a bustling hub of industry and pollution.
And with the quarry currently filled with fresh water, all this liquid and whatever that's swimming in it (fish, otters, monitor lizards) will have to be pumped out and flushed into the sea. After that the real fun begins with clearing of the surrounding vegetation and weekday blasting for granite (until it's all gone and quarrying starts at some other place)
And if you don't have the opportunity to see the place, check out this last ditch report on the quarry area:
Pulau Ubin has its own blog here http://pulauubinstories.blogspot.com/ and for first timers, here's some other sites on activities on the island: