USE OF YARD WASTE COMPOST: EROSION REDUCTION FOR STORMWATER QUALITY PROTECTION

In recent years, improving storm water quality from construction sites has been a concern for federal, state, and local regulatory agencies. A demonstration study was proposed by the City of Lincoln, Nebraska and the Lower Platte South Natural Resources District to compare the water quality improvement characteristics of yard waste compost with other erosion treatments.Six different test plots, each approximately 37-m2, were constructed on a north-facing 3:1 slope in Lincoln, Nebraska. The plots were tested for water quality and vegetation supporting parameters from April 23 to November 1, 2004 using natural events and simulated rainfall. Rainfall, runoff, total suspended solids (TSS), mass erosion, biomass, and cost comparisons were conducted.The natural events and simulated rainfall that were recorded during the study period was close to the local average. It was observed that a 5-cm pneumatically blown compost blanket was approximately 11 times more effective at reducing runoff and approximately 5 times more effective at reducing sediment transport when compared to a straw mat and silt fence treatment.A study of the above-ground biomass in the compost treatments showed that the compost helped to support 10 times more vegetation than the straw mat treatments. Compost performs similarly in cost comparisons to straw mat with silt fence treatments when the compost is applied using a blower truck. The cost of installing compost blankets with a manure spreader was approximately 33-percent of straw mat with silt fence treatments when applied over larger areas.The benefits of yard waste compost use are derived from increased water retention, reduced sediment load, improved fescue growth, and installation costs similar to straw mat with silt fence.