Nitrate Impacts by Golf Courses

Interest in water quality impacts by golf courses has grown significantly in the last two decades, due in part to the intense public scrutiny proposed golf courses receive during the local permitting process. Results from permit-driven studies are frequently not published nor is there usually widespread knowledge about them. This study provides results for the data collected from 80 golf courses in the U.S. and Canada. Forty-four studies (‘44’ included GW, SW, and GW & SW) involving 80 courses from a 20 year period passed our quality control and other review criteria and were incorporated into a detailed data review. Although the underlying database includes 38,717 data points (database entries) from pesticides, pesticide metabolites, total phosphorus, and nitrate analyses of surface water and ground water. This presentation focuses on the results of nitrate with 4,176 data entries combined for surface water and ground water. Widespread and/or repeated water quality impacts by golf courses had not occurred at the sites studied. The MCL (10 mg/L) for nitrate-nitrogen in surface water was exceeded in 20 entries (0.8%). In the ecoregions with exceedances, there was an average of approximately 46 ecocriteria exceedances for surface water. Sixteen of the data entries (1.2%) exceeded the MCL of 10 mg/L in ground water. The inclusion of the EPA’s nitrate ecoregional criteria for surface water, specific ground water regions, and climate zones for data from golf courses provide a comprehensive analysis of water quality impacts of nitrate by golf courses.