Applying livestock manures to agricultural cropland continues to contribute significant levels of sediment and nutrient pollutants to streams and other water bodies. Vegetative buffers have been extensively demonstrated to reduce surface runoff flow, sediment, and nutrient losses. The coal-fired combustion by- product fly ash also has been shown to exhibit significant water-absorption and phosphorus-sorbing properties. This study investigated a vegetative buffer and fly ash pad surface material system for reducing runoff flow and water quality effects from a livestock manure windrow composting facility. Surface runoff, runoff percent of rainfall, total solids, nitrate-nitrogen, ortho-phosphorus, and total phosphorus were researched during 2002-2004 at a central Iowa dairy cow manure windrow composting research facility. Three compost windrow vegetative buffer area ratios comprised the surface runoff treatments that included 1:1, 1:0.5, and 1:0 (no buffer control) area ratios, respectively. The 1:1 and 1:0.5 area ratios represented a 6.0 m-wide x 23 m-long fly ash composting pad area compared to vegetative buffer areas of equal and one-half size, respectively, with three replications of each treatment for a total of nine runoff plots in a randomized complete block design. Results from this study showed significantly  high levels of runoff flow, sediment, and nutrients from the 1:0 control plots compared to the 1:1 and 1:0.5 vegetative buffer plots. The 1:1 and 1:0.5 vegetative buffer treatments were not significantly different and average runoff loss reductions from the 1:1 and 1:0.5 vegetative buffer plots were 98% and 93%, respectively, when compared to the 1:0 control plots. These findings underscore the efficacy of vegetative buffers in reducing surface runoff flow, sediment, and nutrient losses from a livestock manure windrow composting operation. Mass balance analysis results also indicated 41% and 26% of ortho-phosphorus were lost from the compost windrows during the 2004 early season and late season composting periods, respectively. However, only 0.1% and 0.4% of ortho-phosphorus were lost to runoff from the 1:0 control plots during the respective 2004 early season and late season composting periods. These results indicate the significantly lower ortho-phosphorus losses in runoff are attributed to the inherent chemical and physical phosphorus-sorption characteristics of the fly ash composting pad surface material. This vegetative buffer and fly ash pad surface material system application can significantly reduce surface runoff flow, sediment, and nutrient losses from a livestock manure windrow composting facility.