02-10-1997 Council Packet - Laserfiche WebLink

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any of the samples. Overall, at least one fungicide was found in approximately 60 percent of all samples. The Minikahda inlei site had detectable concentrations of either Chlorothalonil or Propiconazole in 6 of 10 samples. The source of the fungicide Is uncertain. It may originate in the watershed upstream of the course or from a small (less than 5 acre) watershed of the course upstream of the corrugated metal ppe discharge point. The Minikahda outlet site had the lowest frequency of detectable fungicide concentrations, 40 percent. This occurred despite the fact that fungicide application was heaviest on this course fTable 5). During at least one runoff event, DACONIL® was detected at the Minikahda inlet site, but not at the outlet site. Presumably, physical and/or biological processes in the drainage ditch or the ponds along the ditch reduced the concentrations of fungicides in the stream flow. The concentrations of the fungicides In the runoff water were low, with a mean of 0.48 ug/l, 0.58 ug/l, and 0.29 ug/l for Chlorothalonil, Propiconazole and Iprodione respectively, (Table 6). The median concentration for all fungicides and herbicides was 0,00 ug/l. There were no significant differences between the mean fungicide concentration at the different sample sites as determined by ANOVA procedures, (p<0.05). Only one of three herbicides, 2,4-D, was detected in runoff from the golf course sites. The chemical was detected on only one occasion in runoff water from the Baker National Golf Course. However, 2,4-D was also detected in one sample at the Minikahda inlet site. The detection frequency is significant lower than the 67 percent occurrence for 2,4-D in stormwater runoff reported by Bannerman, (1990). The difference may be due to a lower detection level used by Bannerman as compared to this study. Neither MCPP or Dicamba was detected in any of the runoff samples. Mercury and cadmium were found in 20 and 8 percent of samples respectively. Only two of the sites, Woodhill and Meadowbrook, had detectable concentrations of the two metals. The mean concentrations for the two heavy metals were 0.348 ug/l and 0.63 ug/l respectively for mercury and cadmium. Presumably the mercury export is from residue from applications of a fungicide which is no longer in use. Mercury export would be expected to decrease over time since the metal is no longer used on golf courses. POLLUTANT EXPORT Export of nutrients from the golf courses in 1994 Is shown in Table 9. There was no significant difference between the export amounts calculated by the various methodologies described earlier. The export rates for phosphorus and nitrogen from three of the sites. Baker, Minikahda, and Woodhill were an order of magnitude less