how to remove unwanted wifi networks

Device: iPad Air (Wifi)

Model: ME906B/A

OS:10.1.1

Problem:

It seems to be taking longer and longer to connect with wifi when I boot up. I am wondering if this is because of gradually collecting a large number of networks over the years and the OS is searching through them all to find one that it can connect with. Is there any way to remove old networks that are no longer valid?