No abstract

The authors gratefully acknowledge the cooperation of numerous property owners who provided access to sampling locations on their land. We also wish to acknowledge the numerous organizations and individuals who have helped distribute our publications to the interested public. Appreciation also is extended to the following personnel of the U.S. Geological Survey: James B. McConnell for his tireless efforts to provide technical review of many of the NAWQA reports; Maurice D. Winner for his thoughtful reviews and approval of untried report products; and finally Caryl J. Wipperfurth, and Carolyn A. Casteel of the Georgia District publications unit for their timeliness and attention to quality. Photographs without credit listed were taken by one of the report authors. • Front Cover-Photograph of downtown, Atlanta, Ga., March 30, 1997, reprinted from Georgia Aerial Surveys, Inc., and published with permission. • Back Cover-Photographs of Horse Trough Falls in the headwaters of the Chattahoochee River (photograph by Alan M. Cressler, USGS); Morgan Falls Dam on the Chattahoochee River, built in 1904 to power trolley cars in downtown Atlanta; and the Apalachicola Bay Estuary, located at the mouth of the ACF River Basin-the bay is prized for commercial fishing and oyster and shrimp harvesting. From its headwaters on the forested slopes of the Blue Ridge Mountains, the Chattahoochee River begins its course toward the Gulf of Mexico. Along the way, the river flows through poultry production areas of northern Georgia, the growing metropolis of Atlanta, and numerous reservoirs surrounded by rolling forests and farmlands of Georgia and Alabama. The Flint River begins beneath the runways of Atlanta's Hartsfield Airport, but is quickly surrounded by rolling forests and farmlands, as well. Where Georgia, Alabama, and Florida meet, the Flint and Chattahoochee Rivers join to form the Apalachicola River. The Apalachicola River finishes the journey to the Gulf of Mexico winding its way through large expanses of coastal forests of the Florida Panhandle. The seemingly untouched headwaters and mouth of this river system give few hints to its role as a vital source of water for drinking, generating power, recreation, assimilating wastes, irrigating crops, transportation, and producing seafood. The action is in between.

Modern agricultural practices in the United States have resulted in nearly unrivaled efficiency and productivity. Unfortunately, there is also the potential for release of these compounds to the environment and consequent adverse affects on wildlife and human populations. Since 1993, the National Water-Quality Assessment (NAWQA) program of the U.S. Geological Survey has evaluated water quality in agricultural areas to address these concerns. The objective of this study is to evaluate trends in pesticide concentrations from 1993-2005 in the surficial and Upper Floridan aquifers of southwest Georgia using pesticide and pesticide degradate data collected for the NAWQA program. There were six compounds-five herbicides and one degradate-that were detected in more than 20% of samples: atrazine, deethylatrazine (DEA), metolachlor, alachlor, floumeturon, and tebuthiuron. Of the 128 wells sampled during the study, only eight wells had pesticide concentrations that either increased (7) or decreased (1) on a decadal time scale. Most of the significant trends were increasing concentrations of pesticides in older water; median pesticide concentrations did not differ between the surficial and Upper Floridan aquifers from 1993 and 2005. Deethylatrazine, in the Upper Floridan aquifer, was the only compound that had a significant change (increase) in concentration during the study. The limited number of wells with increases in pesticide concentrations suggest that ground-water sources of these compounds are not increasing in concentration over the time scale represented in this study.

No abstract

The Chattahoochee River National Recreation Area (CRNRA) attracted approximately 2.9 million visitors in 1999 with nearly 30 percent of the visitors participating in water-based activities such as fishing and boating (William J. Carroll, National Park Service, oral commun., 2000). The CRNRA contains about three-fourths of all public green space in a 10-county area of Metropolitan Atlanta (Kunkle and Vana-Miller, 2000). 20 85 B u fo rd D a m