It is important to prevent sediment contained in construction site runoff, such as highway construction, from flowing offsite, where it can contaminate wetlands and other receiving waters. Hay bales and silt fence are typical practice for sedimentation control. An alternative sedimentation control method is the use of compost application, in the form of blanket or berm applications, which also provides erosion control. Presented herein is a comparison of the chemical characteristics of leachate taken from the effluent of hay and compost. The comparison can be used as a means to evaluate the potential impact of the sedimentation control method on nearby wetlands and surface water. The purpose of this research presented in this paper is to determine the environmental acceptability of wood wastes and composted materials from various sources throughout Massachusetts to control sedimentation. Nutrient analytes consisted of total organic carbon, total nitrogen, and total phosphorus. Chemical analytes included nitrate, nitrite, and ammonia. Biological analytes included enterococci and E. coli. The total suspended solids and pH were also measured. Forty total samples were collected. Synthetic precipitation was passed through each sample and the effluent was collected at various time intervals for analysis. To establish acceptability thresholds, the measured concentrations and parameters were compared with those of hay from hay bales as the current use of hay bales is considered acceptable. Overall, concentrations decreased with leaching time, and hay samples were generally higher than compost samples in all categories. It is significant to mention that the average compost nitrogen-carbon ratio was 1:10, typical for plant organic material. Unlike compost, hay samples supported significant amounts of microbial re-growth. The compost leachate was more buffered than the hay leachate. Replicate sample data for both total organic carbon (TOC) and total nitrogen (TN) are supportive of repeatability in test methodology.
Abstract