Alright, despite varying answers from all of the CSRs at Wells Fargo, I believe I have their fee structure for international ATM withdrawals figured out...
$5 flat fee for any ATM withdrawal plus any charges added by the ATM itself. The 3% "conversion fee" on purchases made with a debit card does not apply to ATM withdrawals.
My question is what exchange rate can I expect to get when I withdraw Euros from an international ATM? Is the rate established by the banks that owns the ATM or by Wells Fargo?
Will it be the market rate (http://www.xe.com) or the markup rate quoted by Wells Fargo for in-store cash transfer (https://www.foreignexchangeservices.com/cfx/todaysrates)?
I have made some purchases in Euros with my Capital One credit card and have confirmed that the exchange is at the market rate and they do not add any fees.