Service life of treated and untreated Black Hills ponderosa pine fenceposts

Service-life tests indicate that ponderosa pine fenceposts treated with preservatives performed well after field exposure of 30 years. Treating plants in the Black Hills area used commercial methods to treat the posts with creosote, pentachlorophenol, and waterborne arsenicals. Test sites were in the northern Great Plains-one in the semiarid western portion near Scenic, South Dakota, the other in the more humid eastern portion near Brookings. The annual service cost of the untreated posts ranged from $1.06 to $1.18 per post depending upon test plot location. The lowest annual cost of the treated posts was $0.85 per post.