It's estimated that there are approximately 150 million wood poles in service in the United States. Each year, approximately 4 million of those poles are replaced as they reach the end of their service life. Wood poles are traditionally considered to have an effective service life of 40 years; however, there is an increasing body of evidence that shows poles can last more than 80 years if they are properly inspected and remedially treated on a cyclical basis. Given that evidence, it's not unrealistic to assume that 2 million (50%) of those 4 million poles would still be in service had they been inspected and remedially treated on a regular basis*.
Extending pole life promotes the efficient use of trees and reduces the potential waste of this important resource. Forestalling the replacement of two million poles saves two million large trees:
Improve Air Quality
Avoiding the unnecessary harvest of two million trees each year means those trees are still in our forests producing oxygen and absorbing carbon dioxide (CO2) - an estimated 96,000,000 lbs of CO2 each year!
Reduce Chemical Use
Reducing the need for new poles also reduces the need for chemicals and petroleum carriers used in their manufacture. The typical distribution pole contains approximately 6.4 pounds of chemical/active and 128 pounds of oil. Forestalling the replacement of two million poles each year may save more than 35 million6 gallons of fuel oil per year.
The expense associated with replacing an in-service wood utility pole is estimated at more than $3,000. The cost to replace 2,000,000 poles is approximately $6 billion dollars! Net the $6 billion figure down by the cost of inspecting and remedially treating those two million poles8 over their useful service life of 80 years, and there is still a surplus of $5.4 billion.
When poles no longer meet code requirements as a result of decay or damage, steel reinforcement or composite restoration can restore bending capacity and add years of additional service life at a FRACTION of the cost of replacement.
Pole restoration programs and proper inspection and treatment programs can significantly extend the useful life of wood poles. As a result, many utilities are presently capitalizing pole restoration and some portion of the inspection/treatment cost, allowing them to realize substantial operating benefits and a positive impact on earnings.
Empire State Electric Energy Research Corporation (ESEERCO) commissioned O'Brien & Gere Engineers, Inc. to conduct an independent field study and associated risk assessment of remedial pole treatments and evaluate the potential ecological and human health impacts related to the application of five remedial wood preservatives to electric utility distribution poles. Among those five preservatives were four Osmose products: Osmoplastic® (preservative paste), Woodfume® (liquid fumigant), Hollow Heart® (liquid internal treatment), and Cop-R-Nap® (liquid internal treatment).
The study, conducted in the Adirondack Park wetlands, demonstrated that (when applied as directed) remedial wood preservatives have a unique affinity for wood and do not pose a significant environmental risk.
Since that study was published many years ago, Osmose has continued to search for ways to increase the efficacy of its remedial treatments while optimizing the level of active ingredients. In 2008, Osmose released MP400-EXT, a highly-effective waterborne remedial paste with the lowest toxicity rating of any paste on the market at the time. In 2014, we released the next generation of preservative technology - MP500-EXT. MP500-EXT delivers broad-spectrum control of wood-destroying decay fungi with an even further improved environmental profile.
*Assumptions regarding the remaining 50% (2 million) poles: Assume 1 million did have an inspection and treatment program in place; they had simply reached the end of their useful life (60-80 years) despite maintenance efforts. Assume that the remaining 1 million were replaced due to circumstances beyond the control of treatment (storm damage, automobile damage, etc).
1 Building a 2,000 square foot home requires approximately 11,120 board feet of lumber according to Penn State's Sustainable Forestry Department. A 42' X 20" tree can produce 274 board feet of lumber. You would need approximately 41 42' X20" trees to build a 2,000 square foot home.
2 The average home burns 2.5 cords of wood per year. One cord of wood contains 128 cubic feet of wood. Three cords of wood contains 320 cubic feet. There are 22.9 cubic feet of wood in one 42' X 20" tree. Therefore, it takes 14 trees to produce 2.5 cords of wood.
3 A single large tree absorbs approximately 48 lbs of CO2 each year.
4 According to figures obtained from the Environmental Protection Agency (EPA) and the Federal Highway Administration (FHWA), the average automobile (mid-size sedan) emits 10,534 lbs of carbon each year.
5 According to the U.S. Energy Information Administration (EIA), one ton (2,000 lbs) of bituminous coal produces 4,931 lbs of carbon.
6 A gallon of fuel oil weighs approximately 7 pounds. The fuel oil used in the manufacture of utility poles is most similar to diesel oil. A pound of diesel oil weighs 7.3 pounds.
7 According to the FHWA, the average automobile gets 22.1 miles per gallon of gasoline. The number of miles driven per year is assumed to be 12,000 miles for all passenger vehicles. Therefore, the average automobile uses 418 gallons of gasoline per year. The FHWA gives an average value of 22.1 MPG for passenger cars. Since diesel cars are considered to be 30-35% more fuel efficient than gasoline-fueled cars, we used 28.73 as the average MPG for diesel vehicles.
8 The average cost for inspection and remedial treatment is $40 per pole. Assuming the pole is treated 7 times (once every 10 years, beginning at 10 years) over its useful life of 80 years, the lifetime cost for inspection and maintenance would be $280 per pole.