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.
However, each state has their own law on sexual consent. This law states that a relationship cannot turn sexually until both is of legal age (age of consent). If a person is an adult and have sex with someone under the age of consent, that person of age could go to jail. Most states have the age of consent set at 16.