You didn't list the model number for your trailer, so finding the "exact specs" is only a "best guess". On the trailer sidewall, next to the entry door, just under the grab bar/handle is a metal foil decal with the model number.
Anyway, from the Keystone website, https://www.keystonerv.com/travel-tr...ingdale/specs/
When you go to that link, in the upper right corner you'll find "select year". Use the pulldown menu to select 2006 and look up your trailer by model number. The 2006 Springdale trailers in the 32' range all look to have a 50 gallon fresh water tank and those with three holding tanks, the black tank ranges from 28-32 gallons and the two gray tanks range from 28-32 gallons as well. So, my guess would be that your 2006 Springdale has about a 30 gallon black tank and two gray tanks with a total capacity of 56-64 gallons.