Submitted to: Journal of Environmental Monitoring
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/7/2010
Publication Date: 6/4/2010
Publication URL: http://handle.nal.usda.gov/10113/54156
Citation: King, K.W., Balogh, J.C. 2010. Chlorothalonil and 2,4-D Losses in Surface Water Discharge From a Managed Turf Watershed. Journal of Environmental Monitoring. 12(8):1601-1612. Interpretive Summary: Agrichemical application is a necessary practice for maintenance of both production and recreational turf facilities. Quantification of agrichemicals from managed turf watersheds is rare. We measured water quantity and quality for a six year period at a golf course in Duluth, MN to quantify the surface losses of two commonly used pesticides, chlorothalonil and 2,4-D. The results indicate that chlorothanil and 2,4-D mass losses were small with respect to mass applied. However, concentrations of chlorothalonil occasionally exceeded acute toxicity levels for aquatic organisms. Maximum 2,4-D concentrations approached the maximum contaminant level. These results highlight the need for watershed stakeholders to develop and adhere to watershed management plans that integrate best management practices for managed turf systems.
Technical Abstract: Managed turf sites (golf courses) are the most intensively managed landscapes in the urban environment. Yet, long-term watershed scale studies documenting the environmental transport of agrichemicals applied to these systems are rare. The objective of this study was to quantify the surface runoff losses of two commonly applied pesticides (chlorothalonil and 2,4-D) resulting from prevailing practices on a managed golf course. Inflow and outflow discharge waters on a subarea of Northland Country Club located in Duluth, MN were measured for both quantity and quality from April through November from 2003 to 2008. The median chlorothalonil outflow concentration (0.58 ppb) was significantly greater (p<0.05) than the inflow concentration, which was below the detection limit (0.07 ppb). Similarly, the median outflow 2,4-D concentration (0.85 ppb) was significantly greater (p<0.05) than the inflow concentration (0.31 ppb). Chlorothalonil concentrations occasionally exceeded acute toxicity levels (7.6 ppb) reported for rainbow trout. No 2,4-D concentrations exceeded any human or aquatic species published toxicity level; however, the maximum measured 2,4-D concentration (67.1 ppb), which rarely occurs, did approach the 70 ppb maximum contaminant level (MCL) for that compound. Losses of both pesticides were detectable throughout the annual sampling period. Mean annual chlorothalonil loading was 10.5 g/ha or 0.3% of applied, while mean annual 2,4-D loading was 4.9 g/ha or 0.5 % of applied. The findings of this study provide quantifiable evidence of agrichemical transport resulting from typical turfgrass management and highlight the need for implementation of best management practices to combat the offsite transport of agrichemicals used in professional turf management.