Good idea to document determination. - Particularly if you conclude you are not subject to the rule. - Not a rule requirement. See Section 2.4 of SPCC guidance document. http://www.epa.gov/emergencies/docs/oil/spcc/guidance/2_Applicability.pdf.
The age of consent is eighteen. With parental consent, parties can marry at age seventeen with the exception that if one party does not have a parent who resides in the state and one party has been a resident in Oregon for at least six months, then no permission is necessary.
There are several federal statutes related to protecting minors from sexual predators, but laws regarding specific age requirements for sexual consent are left to individual states, territories, and the District of Columbia. Depending on the jurisdiction, legal age of consent ranges from 16 to 18 years old.