2003 Toyota Corolla There Kind Leakage Underneath Radiator On Driver Side

There is some kind of leakage underneath the radiator on the driver side. It is mildly sticky. I have attached a photo of the drippage, which is green in color. The antifreeze coolant is also green in color. Hence, my guess is that it is the coolant leakage. Since it is mildly sticky, I am curious as to what else it could be. Could the leak be from anything else? How serious this issue could turn into? Thanks in advance!!