This was probably caused years ago (2007) because off applying the script from commit 89c9a3b4 migration-historic/320-330/postgresql/001_add_brazilian_states.sql without the proper NLS_LANG variable set in oracle
It is important, when applying this script to set the NLS_LANG properly, suggested value is:
export NLS_LANG=AMERICAN_AMERICA.UTF8
Carlos Ruiz