Application of a Copper Boron Paste, or a Copper Naphthenate solution to the area under an in-service tie plate, will greatly prolong the service life of railroad ties. Some ties are removed from service in a main line, re-classified, then returned to service in a spur or secondary line. The adzed area of these ties should be treated before they are reinstalled. Anytime a drill hole, end-cut, or other modification is made to a treated wood tie, an approved AWPA M-4 preservative should be applied to the exposed area. Tenino Copper Naphthenate meets this specification for ground contact.