Urban Pesticides Risk Assessment and Management Review QUANTITATIVE ANALYSIS OF OVER 20 YEARS OF GOLF COURSE MONITORING STUDIES REUBEN D. BARIS,STUART Z. COHEN,* N. LAJAN BARNES,JULEEN LAM, and QINGLI MA Environmental & Turf Services, 11141 Georgia Avenue, Suite 208, Wheaton, Maryland 20902, USA (Submitted 17 February 2009; Returned for Revision 29 August 2009; Accepted 3 February 2010) Abstract —The purpose of the present study was to comprehensively evaluate available golf course water quality data and assess the extent of impacts, as determined by comparisons with toxicologic and ecologic reference points. Most water quality monitoring studies for pesticides have focused on agriculture and often the legacy chemicals. There has been increased focus on turf pesticides since the early 1990s, due to the intense public scrutiny proposed golf courses receive during the local permitting process, as well as pesticide registration evaluations by the U.S. Environmental Protection Agency under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). Results from permit-driven studies are frequently not published and knowledge about them is usually not widespread. Forty- four studies involving 80 courses from a 20-year period passed our quality control and other review criteria. A total of 38,827 data entries (where one analysis for one substance in one sample equals a data entry) from pesticide, pesticide metabolite, total phosphorus, and nitrate analyses of surface water and groundwater were evaluated. Analytes included 161 turf-related pesticides and pesticide metabolites. Widespread and/or repeated water quality impacts by golf courses had not occurred at the sites studied, although concerns are raised herein about phosphorus. Individual pesticide database entries that exceed toxicity reference points for groundwater and surface water are 0.15 and 0.56%, respectively. These percentages would be higher if they could be expressed in terms of samples collected rather than chemicals analyzed. The maximum contaminant level ([MCL]; 10 mg/L) for nitrate-nitrogen was exceeded in 16/ 1,683 (0.95%) of the groundwater samples. There were 1,236 exceedances of the total phosphorus ecoregional criteria in five ecoregions for 1,429 (86.5%) data entries. (This comparison is conservative because many of the results in the database are derived from storm flow events.) Thus, phosphorus appears to present the greatest water quality problem in these studies. Pesticides detected in wells had longer soil metabolism half-lives (49 d) compared with those not detected (22 d), although the means were not significantly different. Environ. Toxicol. Chem. 2010;29:1224–1236. # 2010 SETAC Keywords —Pesticide Nitrate Phosphorus Golf Water INTRODUCTION The subject of golf course design, construction, and manage- ment raises many environmental issues that are frequently discussed among government officials and the general public, particularly in the context of reviews of land development permit applications. This issue has practically no limitation in scope, geographically or in subject matter. For example, comprehensive environmental impact assessments are required for proposed golf courses in China and Korea [1]. Avian impacts had been noted for turf insecticides whose turf use has since been banned in the USA (e.g., [2]). Concerns about aquatic macroinvertebrate impacts have been documented in Canada [3] (although these investigators did not use upstream reference points), and analogous concerns about amphibians have been studied elsewhere [4–6]. Pesticide use on golf courses has been examined in comparison with agricultural pesticide use on more than 80 crops [7]. Proactive environ- mental stewardship approaches for golf course development and management have been written and recommended for overall environmental protection (e.g., [8–10]), as well as for protection of amphibians and their habitats [11]. A key focus of many discussions regarding known or potential golf course impacts has been water quality. Thus comprehensive data and assessments of golf course water quality impacts in several regulatory and scientific con- texts are needed. Regulatory decisions regarding environmental permitting at the local scale, as well as pesticide registration decisions at the state and national scales, could be better advised by such an analysis. Researchers could use such information to guide the filling of data gaps and/or could use the data as one component of ecosystem impact analyses. We had previously obtained water quality monitoring data from 17 studies of 36 golf courses, and conducted a meta- analysis of the data [12]. The previous review did not include phosphorus (P), and the U.S. Environmental Protection Agency (U.S. EPA) has since published ecoregional criteria for total phosphorus (TP) and total nitrogen (TN) that are very low, i.e., typically 0.2 ppm or less for TP in lakes and reservoirs (U.S. Environmental Protection Agency, Office of Water; http:// www.epa.gov/waterscience/criteria/nutrient/ecoregions), con- centrations that are often below background in our experience. Data from large areas of the North American continent were also lacking. Finally, data were insufficient for evaluating temporal trends of the analytes. Many more monitoring studies were in progress at the time of our 1999 paper. Thus, the purpose of the present study is to update the data collection from the previous effort [12] and expand the analyses of the data to include TP, as well as the evaluation of temporal and spatial trends in the data. The original data set had several limitations. A number of these limitations were mentioned in the 1999 publication [12], such as the inability to conclude that the reported concentrations provided true national estimates for golf course impacts on Environmental Toxicology and Chemistry, Vol. 29, No. 6, pp. 1224–1236, 2010 # 2010 SETAC Printed in the USA DOI: 10.1002/etc.185 All Supplemental Data may be found in the online version of this article. * To whom correspondence may be addressed (ets@ets-md.com). Published online in Wiley InterScience (www.interscience.wiley.com). 1224