I am an hourly employee and have now been told that my my entire department must take a phone to be on-call for the weekend and evening hours. My hours are basically booked with my children's activities on the weekends and evenings, at times I may not be able to get a signal depending on where the activity is. My question is do I have to do this? - and yes they do pay for it.

If this is now one of the requirements of your postition then yes, you have to do it or risk being disciplined or even fired.

I have been here for a year and they are just now instituting this. I just can't believe that I have to put my personal life on hold after working 8 hours to still answer more calls - which must be returned within 30 minutes. What happens when I am in a place where there is no signal? I have four children so we are pretty active with all of their activities and now I can actually lose my job by not returning a call within 30 minutes after working all day.

It doesn't matter that they only just implemented it. It's still legal.