Laundry facilities are located at the quiet pools. We used quarters, so I don't remember for certain if the machines took dollar bills, but I think I remember change machines!
All POR laundry facilities are at the quiet pools (not the main pool). For example, I used the laundry facilities in Alligator Bayou section 24-28. It had 8 washers and 10 dryers. Washers are $2 for 30 minutes. Dryers are $2 for 30 minutes. I did a load of darks and whites each day. I often found that I had a few items that I had to pay another $2 to dry longer. The change machines definitely change $1 and $5 bills, but if you bring your own quarter rolls that will save you time. Definitely bring your own soap - the new tabs by Tide, Purex, etc. are wonderful! Also, bring dryer sheets. Some of the machines's softener lights did not light up so the dryer sheets are definitely the way to go. It is very convenient having the facilities near the pool. I usually do the wash in the afternoon when the family is enjoying the pool