Saturday is the due date to pay the first half of property taxes. Marion County Treasurer Denise Emal says the deadline mainly affects people that have paid off their home or people that have a mortgage without an Escrow. You can pay via mail, at the Treasurer’s Office, or online at the Iowa Treasurer’s website. Payments need to be made or postmarked by the end of September, or a 1.5 percent penalty will be assessed.