Oregon Revised Statutes Public Health and Safety § 448.271

(1) In any transaction for the sale or exchange of real estate that includes a well that supplies ground water for domestic purposes, the seller of the real estate shall, upon accepting an offer to purchase that real estate, have the well tested for arsenic, nitrates and total coliform bacteria. The Oregon Health Authority also may, by rule, require additional tests for specific contaminants in specific areas of public health concern. The seller shall submit the results of the tests required under this section to the authority and to the buyer within 90 days of receiving the results of the tests.

(2) The failure of a seller to comply with the provisions of this section does not invalidate an instrument of conveyance executed in the transaction.