Oregon constitution
article XI-h: pollution control
Section 2

The facilities for which funds are advanced and for which bonds, notes or other obligations are issued or made and acquired pursuant to this Article shall be only such facilities as conservatively appear to the agency designated by law to make the determination to be not less than 70 percent self-supporting and self-liquidating from revenues, gifts, grants from the Federal Government, user charges, assessments and other fees. This section shall not apply to any activities for which funds are advanced and shall not apply to facilities for the collection, treatment, dilution, removal and disposal of hazardous substances.