Preservative migration from treated wood products has raised concerns among regulators, especially when the biocides move into surface waters. In most cases, chemical levels are well below the acceptable minimum level, but can become a concern if large quantities of treated wood are stored in one location. One such case would be a location where utility poles are stored for use in emergency repairs. The potential for preservative migration from copper naphthenate treated poles in storage was evaluated over a 2 year period. Copper was always present in rainfall runoff from the poles at levels mostly ranging from 2 to 12 ppm. Neither rainfall amount nor the interval between rainfall events had a large effect on copper levels in runoff, suggesting that metal migration could be modeled using the extent of wood surface exposed to precipitation. The data were used to model three different storage scenarios and these results were used to predict copper levels at various depths in the soil beneath stored poles. The results can be used to manage pole storage to minimize migration.

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