Wood Chips as a Soil Cover for Construction Sites With Steep Slopes

Wood chips were studied for their efficacy in controlling soil erosion on a steep construction site with disturbedsoils. The purpose of the research was twofold: to determine if wood chips could be used to reduce the offsite movement ofsoil during construction activities, and to find an environmentally sound alternative to the landfill disposal of wood wastesgenerated in the urban forest. The research was conducted on field plots that received natural precipitation. Twelve erodibleplots were established on an embankment with a 55% slope and an elevation change of nearly 12 m. Each plot had a widthof 3 m and a horizontal slope length of 10 m. A series of flow dividers was installed at the toe of each plot to measure runoffand sediment. Four treatments were studied: large wood chips, small wood chips, a mixture of wood chip sizes, and a controlwith no chips. The mixture of wood chip sizes represented the size distribution that was found to occur from chippers. Thewood chips were applied at a rate that covered 80% of the soil surface. The erosion rate for the small wood chip treatment was not significantly different from the zerocover plots. The erosionrates from the large wood chip and mixture of chip sizes were not significantly different from one another, but were significantlydifferent from the zerocover treatment. Overall, in comparison to the zerocover treatment, the small wood chip treatmentreduced erosion by 22%, the large wood chips reduced erosion by 78%, and the mixture of chip sizes reduced erosion by 86%.The results of this project indicate that wood chips (as produced by a chipper) should be utilized as a soil cover and need notbe discarded as solid waste.