Solution for Low College Attendance
I have the same problem.
One (not perfect) solution is to build all higher education like university to bypass the college problem. Make sure you have some housing for workers not too far away from the landfill and outside connections that can provide education for people not living near the school in the center.
Try to at least give first level of school education to further outside communities on the mapedge – they will find a way to higher education after that if it available somewhere. Not a perfect solution but what worked for me so far.
Also education takes for ages to develop so make sure to grow your city slowly or try to hold out at some point of growth until education has catched up with population sizes.