UPDATE (April 7, 2018 at 5:05 p.m.):
The semi-truck that overturned was carrying chicken.
Officials with California Highway Patrol say the driver of that truck was driving on southbound on the 99 and attempted to get on the Highway 58 ramp when they lost control.
Environmental Health was also called out due to the rain carrying motor oil into some nearby drain.
Two lanes have been able to reopen.
The California Highway Patrol reported a crash on SB 99 that was causing major delays.
A semi-truck overturned on Saturday afternoon just after 1 p.m. near Stockdale Highway.
We will continue to update this story as more information comes into the newsroom.