Would I be able to fill up my 8 gallon water jugs here or anywhere in Primm for that matter? Ill be camping in the area and have a portable shower but no means to carry enough water at once to last the trip.

There are many ways to fill ur water jugs at that location,,

There is an rv park at the flying j

This location is next to a casino and the bathrooms are big, there's also sinks in the store area to use. May need a hose with a funnel leading to the 8 gallon hugs or outside of the fuel lines are water services. Don't think it would be for consuming though.

Flying j have station for rv whit water.suver.gas.disel

There is usually water on the fuel islands.

Yep