02-10-1997 Council Packet - Laserfiche WebLink

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I I I I I I I I I I I EXECUTIVE SUMMARY Automatic samplers were installed at four golf courses in the TCMA, (Baker National, Woodhill Country Club, Meadowbiook, and the Minikahda Club) in 1994 to monitor rainfall, rainfall runoff, and collect runoff samples. A total of 67 samples from the four golf courses in the Twin Cities Metropolitan Area were collected and analyzed for the presence of selected nutrients, fungicides, herbicides, and heavy metals. The quantity of runoff leaving the four courses was monitored for all rainfall events, and the total loss of chemicals leaving the courses was calculated. The amounts of pesticides and nutrients applied to the golf courses was recorded. Application of fertilizer, in particular phosphorus, to the golf courses in 1994 was 20 percent of the amounts typically applied to urban lawns. Rve different fungicides were applied to the four courses during the summer. Application frequency was less than normal because of the cool weather. The TCMA experienced only 4 days above 90 degrees Fahrenheit in 1994, significantly less than the average of 14 days. Rainfall in the area was 6 percent above the 136 year average during the study period. The percent of rainfall leaving the courses as runoff was similar at all four sites, 5.8, 7.8, 5.0, and 5.2 percent at Baker, Meadowbrook, Woodhill, and Minikahda respectively. The mean concentrations of total phosphorus, soluble reactive phosphorus, total l^eldahl nitrogen, ammonia nitrogen and nitrate and nitrite nitrogen were 0.521, 0.335, 3.104, 0.724, and 1.307 respectively. Nutrient export from the four courses was very small, an order of magnitude less than export rates reported for urban residential areas. The nutrient export rate cf the four golf courses was similar to the rates reported for undeveloped land. Detectable concentrations of fungicides were observed in 40 of 59 (60 percent) of runoff water samples. The most frequently observed fungicide, chlorothalonil (DACONIL®), was observed in 58 percent of runoff samples. DACONIL® was also the ^ngicide applied in the largest quantity to the golf courses. The concentration of fungicides in runoff water was very low, typically sightly above the detection limits. The median concentration for all fungicides was 0.00 ug/l. As a result, only very small quantities of fungicides were lost from the golf courses in 1994. Approximately 99.5 percent of the fungicides applied to the courses remained on the turf. Only one of three herbicides, 2,4-D, was detected In the 59 golf course runoff samples, and was found in only one sample. Mercury and cadmium were found in 20 and 8 percent of samples respectively. Tlie median concentration of both metals was 0.00 ug/l.