Water Quality in the Apalachicola-ChattahoocheeFlint River Basin

Georgia, Alabama, and Florida, 1992–95

U.S. Department of the Interior

U.S. Geological Survey Circular 1164

science for a changing world
Chief, NAWQA Program

U.S. Geological Survey

Water Resources Division

12201 Sunrise Valley Drive, M.S. 413

Reston, VA 20192

FOR ADDITIONAL INFORMATION ON THE 

NATIONAL WATER-QUALITY ASSESSMENT (NAWQA) PROGRAM:

• 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.

Apalachicola–Chattahoochee–Flint Study Unit, contact: 

District Chief

U.S. Geological Survey

Water Resources Division

3039 Amwiler Road, Suite 130

Atlanta, GA 30360–2824

Information on the NAWQA Program is also available on the Internet via the World Wide Web. You may connect to 

the NAWQA Home Page using the Universal Resources Locator (URL):

http://wwwrvares.er.usgs.gov/nawqa/nawqa_home.html

The Apalachicola–Chattahoochee–Flint Study Unit’s Home Page is at URL: http://wwwga.usgs.gov/nawqa
U.S. GEOLOGICAL SURVEY CIRCULAR

Water Quality in the Apalachicola–

Chattahoochee–Flint River Basin, Georgia, 

Alabama, and Florida, 1992–95

1164

By Elizabeth A. Frick, Daniel J. Hippe, Gary R. Buell, 

Carol A. Couch, Evelyn H. Hopkins, David J. Wangsness, 

and Jerry W. Garrett

CONTENTS

National water-quality assessment program ................ 1

Summary of major issues and findings ......................... 2

Environmental setting....................................................... 4

Study design and data collection..................................... 6

Hydrologic conditions....................................................... 8

Water-quality conditions during flooding caused 

by Tropical Storm Alberto, July 1994 ............................ 9

Major issues and findings:

Pesticides in streams ................................................... 10

Pesticides in ground water ......................................... 13

Nutrients and suspended sediment in streams ....... 14

Nutrients in ground water ......................................... 17

Trace elements and organic compounds in 

bed sediment ............................................................ 18

Historical trends in water quality determined 

from reservoir cores ................................................. 21

Biological indicators of water quality ....................... 24

Water-quality conditions in a national context............ 26

Summary of compound detections and 

concentrations ............................................................... 30

References ........................................................................ 35

Glossary............................................................................. 36
Library of Congress Cataloging in Publications Data

The use of firm, trade, and brand names in this report is for identification purposes only and

does not constitute endorsement by the U.S. Government

Free on application to the

U.S. Geological Survey

Information Services

Box 25286 Federal Center

Denver, CO 80225

U.S. DEPARTMENT OF THE INTERIOR

BRUCE BABBITT, Secretary

U.S. GEOLOGICAL SURVEY

Thomas J. Casadevall, Acting Director

Water quality of the Apalachicola-Chattahoochee-Flint River Basin, Georgia, Alabama, and Florida, 

 1992-95 / Elizabeth A. Frick . . . [et al.].

 38 p. cm. -- U.S. Geological Survey Circular : 1164

 Includes bibliographical references.

 ISBN 0-607-89340-0

 1. Water quality--Florida--Apalachicola River Watershed. 2. Water quality--Chattahoochee River

 Watershed. 3. Water-quality--Georgia-Flint River Watershed. I. Series.

 TD223.5.W38 1998

 363.739’42’0975--dc21 98-14001

 CIP

1998
U.S. Geological Survey Circular 1164 1

NAWQA Program helps U.S. Environmental Protection Agency (USEPA) 

implement new pesticide law

Since the enactment of the Food Quality 

Protection Act (FQPA), passed in August 

1996, USEPA has been required to factor 

potential exposures to pesticides through 

drinking water into already complex procedures used to set pesticide “tolerance levels” 

in foods.

Incorporating potential drinking-water 

exposures into the pesticide tolerance-setting 

process has presented USEPA with many scientific challenges including:

• What reliable data are available on pesticide 

concentrations in surface and ground water 

in the U.S.? How do these concentrations 

vary with location and time?

• How can USEPA account for the considerable geographic variability in geology, hydrology, land use, and agronomic practices in 

estimating profiles of pesticide drinking water 

exposures in various regions across the U.S.?

• What “real world” data are available to 

evaluate and improve computational models 

that USEPA uses to estimate pesticide drinking-water residues for new pesticides entering 

the market?

• What types of surface- and ground-water 

monitoring should USEPA require pesticide 

makers to conduct after new pesticides (or 

significant changes in use areas or practices) 

are approved to verify that actual pesticide 

levels do not exceed those estimated through 

USEPA’s screening procedures?

Building on many years of productive collaboration between USEPA and USGS, the 

NAWQA Program marshaled a wide range of 

its data and expertise to help USEPA address 

these and other questions.

We do not have all of the answers yet by any 

means, but we in USEPA who are charged 

with implementing this part of the new FQPA 

are greatly impressed with the knowledge and 

expertise contributed by NAWQA Program 

scientists and managers to assist USEPA in 

addressing these questions. This collaboration has been facilitated by NAWQA’s dedicating one of its senior hydrologists to work 

with USEPA to help both organizations better 

understand how NAWQA data and tools can 

help USEPA.

USEPA’s Office of Pesticide Programs is a 

very satisfied “customer” of USGS and 

NAWQA water-resources programs.

Joseph J. Merenda, Director

Environmental Fate and Effects Division

Office of Pesticide Programs

U.S. Environmental Protection Agency

Knowledge of the quality of the Nation's streams and aquifers is important

because of the implications to human and aquatic health and because of the

significant costs associated with decisions involving land and water management, conservation, and regulation. In 1991, the U.S. Congress appropriated

funds for the U.S. Geological Survey (USGS) to begin the National WaterQuality Assessment (NAWQA) Program to help meet the continuing need for

sound, scientific information on the areal extent of the water-quality problems,

how these problems are changing with time, and an understanding of the

effects of human actions and natural factors on water-quality conditions. 

The NAWQA Program is assessing the water-quality conditions of more

than 50 of the Nation's largest river basins and aquifers, known as Study Units.

Collectively, these Study Units cover about one-half of the United States and

include sources of drinking water used by about 70 percent of the U.S. population. Comprehensive assessments of about one-third of the Study Units are

ongoing at a given time. Each Study Unit is scheduled to be revisited every

decade to evaluate changes in water-quality conditions. NAWQA assessments

rely heavily on existing information collected by the USGS and many other

agencies as well as the use of nationally consistent study designs and methods

of sampling and analysis. Such consistency simultaneously provides information about the status and trends in water-quality conditions in a particular

stream or aquifer and, more importantly, provides the basis to make comparisons among watersheds and improve our understanding of the factors that

affect water-quality conditions regionally and nationally. 

This report is intended to summarize major findings that emerged between

1992 and 1995 from the water-quality assessment of the Apalachicola–Chattahoochee–Flint River Basin Study Unit and to relate these findings to waterquality issues of regional and national concern. The information is primarily

intended for those who are involved in water-resource management. Indeed,

this report addresses many of the concerns raised by regulators, water-utility

managers, industry representatives, and other scientists, engineers, public officials, and members of stakeholder groups who provided advice and input to

the USGS during this NAWQA Study-Unit investigation. Yet, the information

contained here may also interest those who simply wish to know more about

the quality of water in the rivers and aquifers in the area where they live. 

 Robert M. Hirsch, Chief Hydrologist

Began in 1991

Began in 1994

Began in 1997

Not scheduled yet

EXPLANATION

NATIONAL WATER-QUALITY ASSESSMENT PROGRAM
2 Water Quality in the Apalachicola–Chattahoochee–Flint River Basin, Georgia, Alabama, and Florida, 1992–95

SUMMARY OF MAJOR ISSUES AND FINDINGS

IN THE APALACHICOLA–CHATTAHOOCHEE–FLINT (ACF) RIVER BASIN

PESTICIDES IN STREAMS AND GROUND WATER

• Pesticide concentrations in stream-water samples from all major land uses in the Study Unit were less than current drinkingwater standards and guidelines for lifetime exposure. However, concentrations of one or more insecticides in streams 

draining areas of urban and suburban land use often exceeded chronic exposure criteria for protection of aquatic life. The 

highest measured pesticide concentrations in stream-water samples generally coincided with the growing season when most 

pesticides are applied. However, some pesticides were present at lower concentrations throughout the year (pages 10–11). 

• Herbicides that provide selective preemergence weed control are the predominant type of pesticide detected in small streams 

draining agricultural areas and in large rivers located in the Coastal Plain. Small streams draining urban and suburban areas, 

and large rivers located downstream from urban areas contain a more diverse mixture of pesticides including compounds 

used for insect control, selective preemergence and postemergence weed control, and nonselective weed control (page 10).

• Storm runoff carries much of the total quantity of pesticides present in streams in both agricultural and urban areas of the 

Study Unit. However, the quantities of pesticides transported by streams are low relative to the quantities applied, because 

pesticides are retained in the soil, degraded, or transported by other pathways (page 12).

• Pesticide (and VOC) concentrations in ground-water samples generally were less than U.S. Environmental Protection 

Agency (USEPA) drinking-water standards and guidelines. However, in water samples from shallow ground water in 

Metropolitan Atlanta 14 percent of dieldrin concentrations exceeded drinking-water guidelines (and 5 percent of benzene 

and PCE concentrations exceeded drinking-water standards). These exceedances indicate a potential water-quality concern 

for developing future public-drinking water supplies in the fractured-rock aquifer underlying Metropolitan Atlanta. 

Pesticides were detected least frequently in water samples from shallow ground-water monitoring wells located adjacent to 

cropland and most frequently in samples from springs and wells located in the recharge area to the Upper Floridan aquifer, a 

karst aquifer that is susceptible to contamination (pages 13 and 29).

• Many pesticides detected in ground-water samples either are no longer in use or were in much greater use a decade or more 

prior to the sampling period. Because ground water moves slowly through the subsurface, pesticides currently detected in 

ground water lag changes in crop production and pesticide use patterns (page 13).

NUTRIENTS IN STREAMS AND GROUND WATER

• Nutrient concentrations and yields in streams within the ACF River Basin are generally highest in tributaries draining 

watersheds predominated by poultry, urban, and suburban land use, particularly during stormflow conditions, and in the 

Chattahoochee River downstream from Atlanta. USEPA criteria for total-phosphorus was most often exceeded during stormflow conditions at each of these settings. In general, lower nutrient concentrations and yields are indicative of good water 

quality in watersheds predominated by cropland and forests, the Chattahoochee River upstream from Atlanta, and the 

Apalachicola River near its mouth (pages 14–16).

• In tributary streams studied, more than 60 percent of most nutrient yield occurs during stormflows. In the urban watershed, 

which has the highest percentage of impervious area, more than 80 percent of runoff and nutrient yields occur during 

stormflows. The predominance of stormflow transport is indicative of nonpoint sources of nutrients (pages 15–16).

• Improvements to wastewater-treatment facilities and restrictions on the use of phosphate detergents have significantly 

decreased phosphorus loads in municipal-wastewater effluent discharged to the Chattahoochee River near and downstream 

from Atlanta and in reservoir sediments downstream from Atlanta. However, point sources of phosphorus from wastewatertreatment facilities to the Chattahoochee River and overflows from sanitary and combined sewer overflows to tributaries 

contribute to exceedances of USEPA criteria for total phosphorus. Nonpoint sources of phosphorus continue to increase 

throughout Metropolitan Atlanta as indicated by data upstream from Atlanta (page 16).

• Although nitrate generally is present in low concentrations in ground water in most urban and agricultural areas and in the 

Upper Floridan aquifer, nitrate concentrations only rarely exceed the drinking-water standard. In the major crop-producing 

areas of the ACF River Basin, clay-rich upland soils and extensive flood plains reduce the risk of nitrate contamination of 

ground water and streams, respectively. Nitrate concentrations in tile drains are very high, and where tile drains are present,

they represent an important pathway for transport of nitrate and other agricultural chemicals to streams (page 17).

TRACE ELEMENTS AND ORGANIC COMPOUNDS IN BED SEDIMENTS AND RESERVOIR CORES

• The largest enrichments of trace elements and the highest concentrations of organic compounds in bed sediments are in the 

urban and suburban watersheds draining portions of Metropolitan Atlanta and Columbus, and in main-stem and reservoir 

settings on the Chattahoochee River downstream from Atlanta. Concentrations of mercury, cadmium, lead, and zinc in bed 

sediments of these urban and suburban watersheds increased in direct proportion to the amount of industrial land and 
U.S. Geological Survey Circular 1164 3

SUMMARY OF MAJOR ISSUES AND FINDINGS

IN THE APALACHICOLA–CHATTAHOOCHEE–FLINT (ACF) RIVER BASIN

transportation corridors in these watersheds. Much of the current pollutant load of trace elements and organic compounds is 

from stormwater runoff from impervious surfaces in urban and suburban areas and local and regional industrial emissions 

(pages 18–20).

• In reservoirs located downstream from urban areas, concentrations of lead, zinc, chromium, and copper in sediment cores 

reached maximum concentrations during the late 1960’s and mid-1970’s in response to urban growth and industrial 

development, but have declined as a result of compliance with environmental laws enacted during the mid-1970’s. This is 

particularly true for lead. Atmospheric sources of lead peaked in 1972, when use of leaded gasoline peaked, and have 

continued to decline to present. Concentrations of lead in cores from reservoirs downstream from Atlanta closely mirror 

changes in atmospheric sources and related storm-runoff sources of lead (page 22).

• Concentrations of organochlorine insecticides, particularly DDT and chlordane, and PCB’s in reservoir cores correlate with 

regional use patterns. Although, concentrations of these compounds have declined significantly since being banned, they 

continue to be present in sediments deposited as recently as 1994. The slow rate of decline of chlordane and PCB 

concentrations in sediments deposited in West Point Lake indicate that fish-consumption advisories in the Chattahoochee 

River downstream from Metropolitan Atlanta may continue into the future (page 23).

BIOLOGICAL INDICATORS OF WATER QUALITY

• Within the Piedmont, the health and composition of fish communities are best in streams draining watersheds 

predominanted by forested land use; followed by streams draining watersheds predominated by poultry and suburban land 

use. Streams draining watersheds predominated by urban land use have severely degraded fish communities (page 24).

• The macroinvertebrate status of streams draining watersheds predominated by poultry and forest land use were relatively 

good on the basis of the abundance of pollution-sensitive insects. High stormflows, poor habitat, and the presence of 

chemical contaminants such as insecticides, contribute to severely degraded macroinvertebrate communities in streams 

draining watersheds predominated by suburban and urban land use (page 24).

Although urban and suburban land use accounts for only 5 percent of the ACF River Basin, it has the most 

important effect on stream-water quality. The intensity of the land-use effect on water quality varies in proportion to various measures of urbanization such as impervious area, population density, and percent industrial 

and transportation land use. As the percentage of urban land use increases within a watershed, nutrients, pesticides, trace elements, and organic compounds are more prevalent and occur at higher concentrations in 

streams. Watersheds in the Piedmont with higher population densities generally are drained by streams dominated by a few species of pollution tolerant, mostly non-native fishes, indicating poorer biological condition 

and potentially poorer water quality. Data indicate that the continued urbanization of forested and pasture land 

surrounding Metropolitan Atlanta are likely to be accompanied by increasing detrimental effects on water 

quality in area streams, including the area’s source of drinking water (pages 5, 10–12, 14–16, and 18–25).

In the Coastal Plain of the ACF River Basin, cropland and silvicultural land in upland areas are separated 

from streams by relatively undisturbed riparian flood-plain and wetland habitats. This is in contrast to many 

intensively farmed areas of the United States where wetlands have been drained, channelized or filled, and 

little or no riparian buffers remain between cropland and streams. Several water-quality implications that can 

partially be attributed to these wetland buffer areas to streams include (1) fewer pesticides detected and lower 

pesticide and nutrient concentrations in streams than in other areas of the Nation, (2) lower nitrate concentrations in ground water underlying forested flood plains than in ground water underlying upgradient cropland, 

and (3) reduced disturbance of fish communities during and after large floods (pages 5, 9, 11, 13, 17, and 25).

Despite widespread alteration of the ACF River Basin environment, the basin is noteworthy for its 

remaining biological diversity and support of commercial fisheries for oysters, shrimp, blue crabs, and a 

variety of fin fish in Apalachicola Bay (page 4).
Urban and suburban, 5 percent

EXPLANATION

EXPLANATION

 Land use—Number is percentage 

 of ACF River Basin

 Land use

Agriculture—Includes Piedmont 

 poultry and Coastal Plain

 cropland, 29 percent

Forest, 58 percent

Forested wetland, 5 percent

Water, 3 percent

Atlanta

Columbus

Albany

Dothan

Apalachicola Bay

Flint River

Chattahoochee River

Apalachicola River

Lake Seminole

PIEDMONT

BLUE RIDGE

COASTAL PLAIN

Total

Public supply

Domestic supply

Commercial and 

 industrial

 Irrigation and 

 livestock 

WATER WITHDRAWALS, IN

MILLIONS OF GALLONS PER DAY

1,734

1,734

558

205 144

600

400

200

0

Population served,

 in thousands

Ground

water

Surface

water

PiedmontCoastal

Plain

1990 WATER USE

ENVIRONMENTAL SETTING

4 Water Quality in the Apalachicola–Chattahoochee–Flint River Basin, Georgia, Alabama, and Florida, 1992–95 

The ACF River Basin covers approximately 20,000 square miles in the 

Blue Ridge, Piedmont, and Coastal 

Plain Physiographic Provinces. The 

Chattahoochee and Flint Rivers 

converge at Lake Seminole to form 

the Apalachicola River, which flows 

into Apalachicola Bay and the Gulf 

of Mexico. Basin hydrology, water 

quality, and aquatic ecosystems are 

influenced by 16 main-stem reservoirs 

(13 of which are on the Chattahoochee 

River), 14 associated hydropower 

operations, and dredged navigational 

channels. The reservoirs and dams 

transform riverine environments into 

lacustrine environments, impede 

migration of many aquatic species, 

and trap transported sediment and 

sediment-bound contaminants.

Physiography, climate, and hydrology 

in the ACF River Basin provide 

natural conditions that support a rich 

and abundant diversity of plants and 

animals. Despite widespread alteration 

by people, the basin’s environment is 

noteworthy for its remaining biological 

diversity and support of commercial 

fisheries for oysters, shrimp, blue crabs, 

and a variety of fin fish in Apalachicola 

Bay (Couch and others, 1996).

Urban area as of mid-1970's

Other land use, predominantly 

 forested

Urban area developed 

 from mid-1970's to 1995

Data from U.S. Geological Survey, 1977–80; U.S. Bureau of the Census, 1991; Atlanta Regional Commission,

digital data, 1995; http://www.census.gov/population/www/estimates/countypop.html

Flint River

Chattahoochee River

 Lake Sidney 

 Lanier

Area of Metropolitan Atlanta 

map shown 

below

Metropolitan

Atlanta

Data from U.S. Geological 

Survey, 1977–80; U.S. 

Bureau of the Census, 1991

ALABAMA

GEORGIA FLORIDA

Gulf of Mexico

ACF

Forest land is the predominant 

land use in the ACF River Basin 

and consists mainly of secondgrowth hardwoods and planted 

pine. Agricultural land is used for 

poultry production and pasture in 

the headwaters and for cropland 

in the Coastal Plain. Most wetlands are forested and located in 

flood plains of the Flint and Apalachicola Rivers and their tributaries.

Although urban and suburban land 

use accounts for only 5 percent of 

the basin, it has the most significant effect on stream-water quality. 

Metropolitan Atlanta, the largest 

and fastest growing metropolitan 

area in the Southeast, is in the 

basin’s headwaters. 

Metropolitan Atlanta suburbs 

continue to expand into the head 

waters of the Chattahoochee River, 

the region's main source of drinking 

water. Population in the 13-county 

area (shown to the left) increased 

97 percent from 1970 to 3.1 million 

people in 1995; land area devoted 

to residential, commercial, and 

other urban uses more than tripled 

during the same period.

Surface-water quality in the Piedmont 

of the ACF River Basin is of utmost 

importance because surface water 

provides about 93 percent of public 

water supplied to more than 1.7 million 

people. Rapidly spreading urban 

development and poultry production 

in headwater watersheds create added 

stresses in maintaining sufficient 

surface-water supplies of good quality. 

In the Coastal Plain, ground water provides more than 50 percent of publicwater supply and more than 70 percent 

of irrigation water. Forty-four percent of 

all ground water used within the basin 

was from the Upper Floridan aquifer, a 

karst limestone aquifer that is susceptible to contamination.

Data from: http://h2o.usgs.gov/public/watuse

0

0 20 40 KILOMETERS

20 40 MILES
Since the 1930's, large areas of agricultural 

land in the Piedmont have been abandoned 

and have reverted to forests. The remaining 

agricultural land currently is used for poultry 

production and livestock grazing. Nutrient inputs 

from poultry litter applied to sloping pasture land 

and soil erosion are water-quality issues in the 

headwaters of the Chattahoochee River.

Urban land use within the Study Unit is defined as dense commercial areas and transportation networks associated primarily with 

the city of Atlanta. Urban watersheds contain substantial impervious areas that are 

connected to streams by storm sewers. 

Streams also receive inputs from combined 

sewers and leaking or overflowing sanitary 

sewers. Chemical and microbial contaminants 

from point and nonpoint sources are the primary 

water-quality issues within the urban watersheds.

Suburban land use within the Study Unit 

is defined as established and developing 

residential areas, associated commercial 

areas, and transportation networks. It differs 

from urban land use by the amount of impervious land cover 

and the lack of known point sources but has the same waterquality issues of contaminants from nonpoint sources.

Unlike parts of the United States 

where large, continuous tracts of 

land often are farmed to streambanks, cropland in the ACF River 

Basin generally is limited to well-drained upland areas. The 

long growing season and center-pivot irrigation support a 

broad range of cash crops and several plantings of some 

crops on the same fields during the year. Cropland commonly 

is bordered by extensive forested wetlands (inset). In this 

study, cropland was further subdivided into areas underlain 

by clastic deposits (sands and shales) and carbonate bedrock (karst) to investigate any differences in water quality that 

might be attributed to differences in hydrogeology. Excess 

nutrients and pesticides in ground water and streams are the 

primary water-quality issues within this land use. (Photograph 

of cotton field is by L. Elliott Jones, USGS.)

U.S. Geological Survey Circular 1164 5

Most forested land in the ACF River Basin is silvicultural 

land owned and managed by individuals or corporations for 

pulp and lumber production. These mostly second-growth 

forests are the best available representation of background water-quality conditions in the Study Unit. 

Erosion, sedimentation, and release of nutrients 

following timber harvests are the primary waterquality issues in these forested watersheds. 

(Photograph of Chattahoochee National Forest 

is by Alan M. Cressler, USGS.)

ENVIRONMENTAL SETTING
EXPLANATION

SUBURBAN AND URBAN 

Study area 

Wells 21

Springs 19

CROPLAND 

Study area 

Wells 42 

Study-Unit Survey

Study area

Wells 26

Springs 15

Flow-System Study

Study area 38

Land-Use Study Areas 

GROUND-WATER SAMPLING 

 SITES—Number is sites 

 sampled

Poultry 4

Suburban 4

Urban 5

Forest 6

Cropland, clastic 4

Cropland, karst 4

EXPLANATION

Predominant land 

 use—Number is 

 watersheds studied

Large rivers with mixed 

 land use—3 Basic (B) 

EXPLANATION

STREAM-WATER SAMPLING 

 SITES—Number is sites sampled 

Reservoir cores 8

Tributaries with one pre- 

 dominant land use—

 3 Basic (BT) and 

 3 Intensive (I) 

Basinwide synoptic 70

Bed sediment 48 

 or tissue 33

6 Water Quality in the Apalachicola–Chattahoochee–Flint River Basin, Georgia, Alabama, and Florida, 1992–95

 Snake

Creek (BT)

Chattahoochee River downstream

 from Atlanta (B)

Lime Creek (I)

Peachtree Creek (BT)

Sope Creek (I)

West Fork

Little River

(BT)

 Chattahoochee

 River upstream

from Atlanta (B)

Apalachicola River near

 the mouth (B)

Aycocks Creek (I)

Fall Line

PIEDMONT

COASTAL PLAIN

The primary objectives of NAWQA's 

ACF River Basin study were to document and describe natural and human 

influences on water quality and the 

health of aquatic ecosystems in the 

basin. A nested monitoring network 

was designed to maximize understanding of spatial and temporal 

variability of water quality among 

various physiographic, hydrogeologic, 

and land-use settings within the basin 

(Wangsness, 1997). Additional information about the study design, the 

water-quality and quality-control data, 

and results are available on the Internet 

at: http://wwwga.usgs.gov/nawqa/ . 

Land-Use Effects on 

Stream Quality

The sampling network was designed 

to characterize the effects of land use 

on stream quality at various scales 

and physiographic settings. Water 

chemistry, community-assemblage 

(fish and invertebrates), habitat, bedsediment, aquatic-organism tissue, 

and reservoir-core data were used as 

indicators of stream quality. Basic 

Fixed Sites on large rivers were 

upstream and downstream from 

Atlanta and near the mouth 

of the Apalachicola 

River. Basic and Intensive Fixed Sites were 

chosen on tributaries 

that represent effects of 

poultry, suburban, urban, 

forest, and cropland, 

respectively. Basinwide 

synoptic sites were 

located within watersheds with similar predominant land uses, in 

larger tributaries with mixed land uses, 

and along the three main-stem rivers. 

Focused synoptics were conducted to 

evaluate stream quality in relatively 

small areas. Bed-sediment and aquaticorganism tissue sites are fewer in number but have a similar distribution to 

basinwide synoptic sites. Reservoir 

cores were collected and analyzed 

from all major reservoirs (page 21).

Land-Use Effects on GroundWater Quality

The ground-water network was designed to characterize the effects of 

land use on ground-water quality at 

various scales and hydrogeologic settings. Land-Use 

Studies characterized shallow ground water underlying predominantly suburban and urban land use in 

Metropolitan Atlanta and 

underlying cropland in the 

Coastal Plain. The StudyUnit Survey characterized 

ground-water quality in the 

Upper Floridan aquifer, the 

most used aquifer within 

the ACF River Basin. The 

Flow-System Study was 

located in the Lime Creek 

watershed, a predominantly 

agricultural basin. Wells, tile 

drains, and springs were 

sampled to examine the fate of agricultural chemicals in ground water.

STUDY DESIGN AND DATA COLLECTION

Chattahoochee

River Basin

Flint

River

Basin

Apalachicola

River Basin
U.S. Geological Survey Circular 1164 7

STUDY DESIGN AND DATA COLLECTION

Study 

component Objectives and brief description

Number

of sites

Frequency 

sampled

Constituents 

sampled1/

1/ 1, streamflow; Community assemblage survey: 2, fish; 3, macroinvertebrates; 4, algae; 5, habitat; Bed sediment and reservoir cores: 6, semivolatile 

organic compounds (SVOCs); 7, organochlorine compounds and polychlorinated biphenyls (PCBs), major ions, and trace elements (TE); Tissue: 8, SVOCs, 

organochlorine compounds, and PCBs; 9, major ions and TE; 10, bed material; Water column: 11, suspended sediment; 12, turbidity; 13, field parameters and 

nutrients; 14, major ions; 15, organic carbon; 16, pesticides; 17, volatile organic compounds (VOCs); 18, TE; 19, radon; 20, oxygen 18/16 ratio, hydrogen 2/1 

ratio; Age dating: 21, tritium; 22, chlorofluorocarbons (CFCs); 23, water levels; constituents sampled at small subset of ‘Number of sites’ are in parentheses.

Land-use effects on stream quality

Basic Fixed Sites—

Large rivers with 

mixed land use

Measure concentrations and estimate loads (1) in the Chattahoochee River upstream 

and downstream from Metropolitan Atlanta to better understand suburban and urban 

inputs to the river; and (2) near the mouth of the Apalachicola River to better 

understand outflow from the basin and inflow to the Apalachicola Bay.

3 monthly, 

(March 1993 

through Sept. 

1995)

1, 6, 7, (8), 9, 

11-15, (16)

Basic and Intensive 

Fixed Sites—

Tributaries with one 

predominant land use

Measure concentrations and estimate loads in 18- to 105-square-mile watersheds 

having a predominant land use: poultry, suburban, urban, forest, or cropland. Use 

community-assemblage and habitat data as indicators of surface-water quality. At 

intensive sites, also determine concentration and timing of pesticides in streams in 

watersheds dominated by suburban land use and cropland.

3 Basic monthly, for 

2.5 years

1-9, 11-16

3 Intensive same as above 

plus weeklybiweekly for 

13 months

1-9, 11-16

Basinwide-synoptic 

studies—

Tributaries with one 

predominant land use 

(37), large tributaries 

(19), and main-stem 

rivers (14)

Describe basinwide presence and distribution of nutrients and pesticides during 

primary periods of nutrient and pesticide applications to urban and agricultural lands. 

Use community-assemblage and habitat data as indicators of surface-water quality at 

basic and intensive tributary sites; and a subset of these ecological indicators at 

comparison watersheds with similar predominant land use and at tributary sites to 

Basic and Intensive Sites. Determine variability of water-quality and ecological 

indicators within and among watersheds having similar predominant land use. 

Compare indices among watersheds having different predominant land uses.

70

(includes 

Basic and 

Intensive 

Fixed 

Sites)

3

(June 1993, 

March 1994, 

May 1994)

1, (2), (3), 

(5)-(9),11-13, 

(14), 15, (18)

Focused-synoptic 

studies

(not differentiated on 

opposite page)

Poultry— (1) Evaluate nutrient concentrations and algal community assemblage data 

to understand eutrophication in watersheds predominated by poultry production. 

(2) Evaluate nutrients and turbidity under base-flow and stormflow conditions.

11 1

(May 1995)

4, 13, (14), 15

31 2 (1992-93) 12, 13

Suburban—Evaluate presence and distribution of nutrients and pesticides within Sope 

Creek watershed, the intensively monitored suburban watershed in Metropolitan 

Atlanta, with respect to differences in suburban land use. Also sampled three 

suburban watersheds larger than Sope Creek for comparison in May 1995.

14 3

(Aug 1994, 

Dec 1994, 

May 1995)

1, 12-16

Metropolitan Atlanta and Columbus—Evaluate the presence and distribution of 

nutrients and pesticides across the land-use gradient from heavily urbanized to 

urbanizing watersheds. Twenty sites were within Peachtree Creek.

41 1

(July-August 

1995)

1, (11), 12-16

Tropical Storm Alberto—Determine concentrations in tributaries to the Flint River, 

and the Flint and Apalachicola Rivers during 100- to 500-year flood. Determine 

nutrient and pesticide loads near the mouth of the Flint River. Evaluate post-flood 

effects on fish communities in Lime Creek.

10 1-20

(July 4-27, 

1994)

1, (2), (6), (7), 

(10), 11-16, (17)

Trace-element and 

organic-compound 

occurrence and 

distribution 

survey—Bed 

sediment and tissue

Determine the recent (at the time of sampling) occurrence and distribution of 

potentially toxic compounds in depositional zones of tributaries, main-stem rivers, 

and reservoirs. Streambed and reservoir sediments were analyzed for trace elements 

and hydrophobic organic compounds; and where available, aquatic-organism tissues 

(Asiatic clam, Corbicula, or mosquito fish, Gambusia) were analyzed for trace 

elements and lipophilic organic compounds.

48 1 or 2

(1992-94)

1, 6, 7, (8), (9), 

13

Reservoir core study Determine the historical (from the filling of each reservoir through 1994) occurrence 

and distribution of major ions, trace elements, and organochlorine compounds in 

depositional zones in six major reservoirs.

8 cores,

23 soil 

samples

1 or 2

(1994)

7

Land-use effects on ground-water quality

Land-use studies Agricultural— (1) Describe shallow water quality beneath cropland in the most 

intensively farmed part of the ACF River Basin (includes four forested areas as 

reference sites). (2) Limited study of nutrients beneath poultry and pasture land use 

(Peck and Garrett, 1994).

4 forest,

37 cropland 

wells

2

(1993, 1994)

12-17, 19, (20), 

(21), 23

24 wells 1 (March 1993) 13

Suburban and urban—Describe shallow water quality beneath suburban and urban 

land use. Compare ground-water and surface-water quality in the Metropolitan 

Atlanta part of the Chattahoochee River watershed.

21 wells,

19 springs

1

(1994-95)

12-19, (21), 23

Study-unit survey Describe water quality in the Upper Floridan aquifer, a principal source of irrigation 

and drinking water in the Coastal Plain.

26 wells,

15 springs

1

(1995)

12-21, 23

Flow-system study Evaluate the fate of agricultural chemicals through the shallow ground-water flow 

system that underlies cropland and the adjacent forested flood plain, to areas of 

discharge in ditches, springs, and streams. 

32 wells,

3 springs,

3 drains

1-6

(1993-97)

12-16, (17), 

(20)-(22), 23
Temporal data collection

Spatial data

collection

1992 1993 1994 1995

0

1,000

200

400

600

800

0

100

200

300

400

500

0

800

100

200

300

400

500

600

700

1992 1993 1994 1995

0

15,000

5,000

10,000

DAILY STREAMFLOW, IN

CUBIC FEET PER SECOND

DAILY STREAMFLOW, IN

CUBIC FEET PER SECOND

MONTHLY

STREAMFLOW,

AS PERCENTAGE

OF NORMAL

MONTHLY 

STREAMFLOW,

AS PERCENTAGE

OF NORMAL

Snake Creek—a small watershed (36 square miles)

located in southwest of Atlanta

Spring Creek—a large watershed (485 square miles)

located in southwest Georgia

Normal

Normal

Unusual hydrologic conditions 

such as droughts or floods may 

cause substantial changes in 

stream and ground-water quality 

and in aquatic communities. 

Although the water quality associated with these conditions may 

be of great interest, the short-term 

changes in water quality caused 

by droughts or floods can alter or 

mask the effects on water quality 

from other human and environmental factors being studied.

The ACF River Basin was subjected to periods of unusually dry and wet weather 

during the study period.

Dry weather from the summer of 1993 

through the winter of 1994 caused many 

streams, such as Aycocks Creek—a 

tributary to Spring Creek (hydrograph 

shown above)—to cease flowing.

Rainfall from Tropical Storm Alberto 

caused devastating floods in parts of 

the ACF River Basin. (Photograph of 

the Flint River at Newton, Georgia, is 

by Timothy W. Hale, USGS, July 1994.)

The ACF River Basin has a warm, 

humid, temperate climate. Average 

annual precipitation ranges from 45 

to 60 inches. During the period of 

intensive data collection (1993–95), 

average annual precipitation ranged 

from about 85 to 155 percent of normal. An extended period of dry 

weather from the summer of 1993 

through the winter of 1994 resulted 

in below normal streamflows 

throughout much of the watershed. 

In contrast, rainfall from Tropical 

Storm Alberto caused extreme 

flooding in July 1994—primarily 

in the Flint River Basin. 

Stable streamflow conditions existed 

during spatial surveys, shown by 

arrows (three basinwide synoptic 

surveys and bed sediment and tissue 

surveys, pages 6 and 7), so that differences in water quality among 

sampled sites relate to human and 

environmental factors. However, 

the extended period of dry weather 

coincided with the data-collection 

period to evaluate temporal changes 

in water quality at stream locations 

representing various land uses (Basic 

and Intensive Fixed Sites, pages 6 

and 7). The temporal data-collection 

period is shown by shading on the 

adjacent graph. Aycocks Creek, 

located in an area of cropland underlain by karst bedrock, ceased to 

flow for 6 months from June to 

December 1993, thus limiting comparisons among Aycocks Creek and 

other sites. 

Tropical

Storm

Alberto

HYDROLOGIC CONDITIONS

8 Water Quality in the Apalachicola–Chattahoochee–Flint River Basin, Georgia, Alabama, and Florida, 1992–95
0

2

4

6

8

CONCENTRATION, IN MILLIGRAMS PER LITER AS N

CONCENTRATION, IN MILLIGRAMS PER LITER AS P

FORMS OF

NITROGEN

Nitrate

Organic

0

0.1

0.2

0.3

0.4

FORMS OF 

PHOSPHORUS

Dissolved

Suspended

0

2.5

0

0.05

1.0

1.5

2.0

CONCENTRATION, IN MICROGRAMS PER LITER

HERBICIDES

Alachlor

Atrazine

Cyanazine

Metolachlor

Simazine

Vertically

exaggerated

FLINT

RIVER

DES

MOINES

RIVER

FLINT

RIVER

DES

MOINES

RIVER

FLINT

RIVER

DES MOINES

RIVER

0.5

EXPLANATION

Rainfall, in inches

1-5

5-10

10-15

15-20

20-25

25-28

Chattahoochee

River Basin

Flint River Basin

GEORGIA

River

Chattahoochee

River

Flint

Flint

River

l

Montezuma

Albany

Newton

Columbus

Atlanta

Bainbridge

Americus

For much of the Flint River Basin 

upstream of Albany, Georgia, 10 

or more inches of rain fell during 

Tropical Storm Alberto (July 4–7, 

1994). The worst flooding in the 

Basin occurred between Atlanta 

and Newton, Georgia.

Nutrient and pesticide concentrations were substantially lower during flooding of the Flint 

River following Tropical Storm Alberto in July 1994, than during flooding of tributary 

streams in the Upper Mississippi River Basin in July 1993 (Emitt C. Witt, II, USGS, written 

communication, 1994). Less intensive crop production and more extensive buffering of 

stream sides by forests and wetlands may have contributed to lower nutrient and pesticide concentrations in floodwaters in the Flint River.

The slow rise and fall of floodwaters submerged some cropland and communities 

located near streams for up to a week 

(Photographs are by Timothy W. Hale, 

USGS, July 1994.)

Cropland along Flint River near Oakfield, Georgia

Flint River in Albany, Georgia

 WATER-QUALITY CONDITIONS DURING FLOODING CAUSED BY TROPICAL STORM ALBERTO, JULY 1994

In July 1994, rainfall from Tropical 

Storm Alberto caused devastating 

flooding over a large part of the ACF 

River Basin. Streamflows exceeded a 

100-year recurrence interval throughout much of the Flint River Basin and 

exceeded a 500-year recurrence interval for more than 75 miles of the Flint 

River from Montezuma to Albany, 

Georgia (Stamey, 1995; 1996). 

Floodwaters caused dam breaks; damaged roads, culverts, and bridges; and 

inundated several communities and 

large areas of prime agricultural land. 

Although nutrients and pesticides 

were present in floodwaters, the large 

volume of runoff and redeposition of 

sediment and associated contaminants 

in flood plains may have greatly 

reduced concentrations and downstream transport in floodwaters.

Nitrogen and phosphorus concentrations during flooding were similar to 

long-term average concentrations 

observed at monitoring sites in the 

Flint River Basin. The predominant 

forms of nitrogen and phosphorus in 

floodwaters are associated with 

transported organic detritus and finegrained sediments eroded from upland 

areas, rather than forms that can be 

directly attributed to fertilizer applications and wastewater discharges. The 

quantity of nitrogen and phosphorus 

in floodwaters of the Flint River 

represent just 4.5 and 2.8 percent, 

respectively, of estimated annual point 

and nonpoint sources of these nutrients 

from wastewater discharges, animal 

manure, and fertilizer in the affected 

area (Frick and others, 1996).

Pesticide concentrations in the Flint 

River peaked 4 to 6 days prior to the 

flood crest. Throughout the flood, 

pesticide concentrations in the Flint 

River and its tributaries were well 

below present USEPA drinking-water 

criteria (Nowell and Resek, 1994); 

only the insecticides carbaryl, diazinon, and chlorpyrifos approached 

or exceeded existing guidelines for 

protecting aquatic life. Herbicides 

used for selective preemergence weed 

control for cotton, corn, and peanuts 

were detected at higher concentrations 

than pesticides registered for other 

uses. However, the quantities present 

in floodwaters represented just 0.09 

to 2.4 percent of the estimated annual 

use of these compounds on cropland 

within the affected area (Hippe and 

Garrett, 1995).

Data from U.S. Weather Service,

written communication, 1994

U.S. Geological Survey Circular 1164 9
Pesticides are widely used to control 

weeds, insects, and plant diseases in 

the ACF River Basin. 

0

10

2

4

6

8

AVERAGE NUMBER OF PESTICIDES

DETECTED PER SITE

Insecticides

Forest

 Poultry

Suburban

Urban

 Cropland

(Clastic deposits)

 Cropland

(Carbonate bedrock)

0

2.0

0.5

1.0

1.5

AVERAGE SUMMED PESTICIDE

CONCENTRATION PER SITE,

IN MICROGRAMS PER LITER

Upstream

 from Atlanta

Near Atlanta

Downstream

 from Atlanta

All sites

Piedmont Piedmont Coastal Plain Coastal Plain

Nonselective herbicides

Selective preemergence

 herbicides

Selective postemergence

 herbicides

TRIBUTARIES WITH ONE 

PREDOMINANT LAND USE

LARGE RIVERS WITH

MIXED LAND USE

Herbicides that provide selective preemergence weed control are widely used in the 

ACF River Basin; they are the predominant type of pesticide detected in streams 

draining forested and agricultural areas. Streams draining suburban and urban areas, 

and large rivers located near and downstream from urban areas contain a more 

diverse mixture and higher concentrations of pesticides than other areas of the ACF 

River Basin, and includes compounds that are used for insect control and selective 

preemergence and postemergence weed control and nonselective weed control.

 PREDOMINANT LAND USE SITE LOCATION

MAJOR ISSUES AND FINDINGS

Pesticides in Streams

Pesticides are used to control 

weeds, insects, and plant diseases 

in each of the major land-use areas 

of the ACF River Basin (Stell and 

others, 1995). An estimated 17 

million pounds of 147 different 

pesticide active ingredients are 

applied annually to agricultural land 

in the 20,000-square-mile study 

area (Anderson and Gianessi, 

1995). Unlike much of the Nation, 

pesticides are applied throughout 

much of the year in the ACF River 

Basin and include similar quantities 

of herbicides, insecticides, 

fungicides, soil fumigants, and 

harvest aids.

In the ACF River Basin, spatial surveys (results shown above) indicate 

that pesticides are most prevalent in 

streams draining areas of suburban 

and urban land use. Streams in these 

areas contain compounds used to 

control a broad range of pests, 

including: herbicides used for selective preemergence and postemergence 

weed control on turf; herbicides used 

for nonselective control of weeds, 

shrubs, and trees in transportation and 

utility right-of-way; and insecticides 

used to control pests in gardens, 

grass, ornamental shrubs, trees, and 

structures. In streams draining 

agricultural areas, herbicides used for 

selective preemergence weed control 

predominate, despite the extensive use 

of other types of pesticides. The spatial data indicate that the continued 

urbanization of forested and pasture 

land surrounding Metropolitan Atlanta 

(page 4) are likely to be accompanied 

by increasing numbers and concentrations of pesticides in area streams, 

including the area's source of 

drinking water. 

Pesticide concentrations in streamwater samples from all major land uses 

in the ACF River Basin were less than 

The land-use-based design of the ACF 

River Basin NAWQA study and use of 

highly sensitive analytical methods 

have provided an improved understanding of the occurrence and distribution of a broad range of pesticides 

in streams and selected aquifers in the 

ACF River Basin. Spatial and temporal patterns of pesticide occurrence 

in streams and ground water are 

described and associated in part 

with land use and pesticide use. The 

pesticides used have a broad range of 

chemical and physical properties that 

also control their temporal and spatial 

occurrence in the basin. 

10 Water Quality in the Apalachicola–Chattahoochee–Flint River Basin, Georgia, Alabama, and Florida, 1992–95
Compound

detected*

Frequency of detection,

in percent

Frequency of detection,

in percent

Maximum

concentration

(μg/L)

JanuaryFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecember

Selective preemergence herbicides

Atrazine 96 .38

Benfluralin 14 .022

Metolachlor 15 .068

Pendimethalin 42 .24

Pronamide 10 .021

Simazine 94 8.2

Trifluralin 15 .019

Selective postemergence herbicides

MCPA 19 .42

2,4-D 20 .63

Nonselective herbicides (no particular application period)

Prometon 59 .86

Tebuthiuron 68 .16

Insecticides

Carbaryl 63 .24

Chlorpyrifos 61 .051

Diazinon 92 .45

Malathion 14 .14

*Additional pesticides that were less frequently detected (less than 10 percent of 71 samples 

analyzed): DCPA, deethylatrazine, napropamide, oryzalin, propanil, trichlopyr, 2,4-DB, 

bromacil, diuron, terbacil, p,p-DDE, ethoprop, lindane, parathion, propoxur

Was detected Detected at highest 

 concentration

Application is

 recommended

Compound

detected*

Maximum

concentration

(μg/L)

JanuaryFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecember

Selective preemergence herbicides

Alachlor 21 0.011

Atrazine 64 0.21

Cyanazine 12 0.77

Deethylatrazine 25 .007

Fluometuron 21 1.6

Metolachlor 66 0.34

Norflurazon 14 1.4

Simazine 47 0.16

Trifluralin 21 0.20

Nonselective herbicide (no particular application period)

Tebuthiuron 23 0.050

Insecticide

Fonofos 10 1.2

*Additional pesticides that were less frequently detected (less than 10 percent of 73 samples 

analyzed): benfluralin, bentazon, butylate, ethylfluralin, metribuzin, pendimethalin, 2,4-D, 

p,p-DDE, malathion, ethoprop, carbaryl, and chlorothalonil 

MAJOR ISSUES AND FINDINGS

Pesticides in Streams

Sope Creek—a predominantly suburban watershed 

(29 square miles) in Metropolitan Atlanta 

Lime Creek—a predominantly cropland watershed

(62 square miles) in southwest Georgia

Month when pesticide:

EXPLANATION

Maximum measured concentrations of most pesticides coincided with application periods to turf in the suburban watershed and to 

peanuts, cotton, and corn in the watershed dominated by cropland. Pesticide concentrations generally decreased to less than detectable levels during other parts of the year. However, several compounds persisted throughout the year in the suburban watershed.

USEPA standards and guidelines for 

lifetime exposure in drinking water 

(Nowell and Resek, 1994). However, 

concentrations of one or more insecticides in streams draining areas of 

suburban and urban land use often 

exceeded existing chronic exposure 

criteria for protection of freshwater 

aquatic life. Insecticides are but one of 

several potential chemical and physical 

stressors that exist in these streams.

The highest measured concentrations 

of most pesticides coincided with the 

growing season, from March through 

October, when many of these compounds are used. However, the highest 

measured concentrations of several 

herbicides used for selective preemergence weed control in suburban and 

urban areas peaked during the winter 

months—these compounds are applied to lawns during fall and winter 

months to control winter weeds. 

Winter applications of selective preemergence herbicides on turf coincide 

with periods of high base flow and 

frequent stormflows and may contribute to higher concentrations and quantities of these pesticides in streams 

relative to other pesticides applied 

during the growing season.

Some pesticides persisted in streams 

within the ACF River Basin well beyond their normal application periods. 

These compounds include some selective preemergence herbicides, nonselective herbicides, and insecticides used 

on suburban and urban land; and some 

selective preemergence herbicides used 

on agricultural land. Insecticides commonly were present throughout the 

year in streams draining areas of suburban and urban land use, and in large 

streams that receive runoff from urban 

areas. Concentrations of one or more 

of these insecticides (primarily diazinon, carbaryl, chlorpyrifos, and malathion) exceeded existing guidelines for 

protection of aquatic life throughout 

the year in streams draining these 

areas (Hippe and others, 1995).

Most pesticides present in streams 

draining major land uses in the ACF 

River Basin have chemical and soil 

properties that cause them to have a 

greater potential to run off than other 

less frequently detected compounds. 

Pesticides used for selective preemergence weed control and nonselective 

weed control, in particular, are rather 

water soluble and persist in soils following applications to provide seasonal or longer term weed control— 

these properties also increase their 

potential to run off to streams relative 

to other compounds. Herbicides that 

are used for nonselective weed control 

are applied at up to 10 times the rate 

of similar compounds used for 

selective weed control—these higher 

rates also may increase their potential 

to be present in nearby streams. 

U.S. Geological Survey Circular 1164 11
Stormflows transport from 60 to 90 

percent of the total quantity of pesticides carried by streams draining 

urban and agricultural land in the 

ACF River Basin. Large storms that 

coincide with pesticide application 

periods in particular transport much 

of the annual pesticide loads in 

streams within the basin.

Metolachlor

Simazine

Fluometuron

Atrazine

Alachlor

0

5

10

15

 AVERAGE ANNUAL LOAD, IN

POUNDS OF ACTIVE INGREDIENT

Stormflow

Base flow

Simazine

Atrazine

Pendimethalin

Prometon

Tebuthiuron

Carbaryl

Diazinon

Chlorpyrifos

0

25

5

10

15

20

0.66%

0.31%

0.48%

0.05%

51

16

8.6

4.4 9.2

7.5

.20

.12

14%*

Number is

equivalent

to acreage

with bareground

applications

SELECTIVE

PREEMERGENCE

HERBICIDES

SELECTIVE

PREEMERGENCE

HERBICIDES

NONSELECTIVE

HERBICIDES

INSECTICIDES

Number is percentage of annual pounds 

used. *High percentage probably 

indicates usage is underestimated

EXPLANATION

Number is equivalent to applications 

to an average size yard 

(12,000 square feet)

1970 1975 1980 1985 1990 1995

GROWING SEASON

100,000

0

20,000

40,000

60,000

80,000

ACRES PLANTED

Cotton

Soybeans

Corn

Sorghum

Small grains

Peanuts

CROP STATISTICS FOR MILLER COUNTY, GEORGIA

Data from Georgia Agricultural Statistics Service, 1997

Rye

Oats

Wheat

Soybeans

Sorghum

Corn

Peanuts

Cotton

ROWCROPS

0

5

10

15

20

AVERAGE AMOUNT OF PESTICIDES USED, IN

POUNDS OF ACTIVE INGREDIENT PER ACRE

Harvest aids

Soil fumigants

Fungicides

Insecticides

Herbicides

PESTICIDE USE ON MAJOR

CROPS IN THE ACF RIVER BASIN

Data from Anderson and Gianessi, 1995

SMALL

GRAINS

Sope Creek—a predominantly

suburban watershed 

(29 square miles)

Lime Creek—a predominantly

cropland watershed

(62 square miles)

In the ACF River Basin, plantings of cash crops vary from year to year in response to changing weather and market conditions. From 

1992 to 1995, cotton plantings increased by over 400 percent in many counties, in response to increasing demand for cotton lint and 

improved cotton yields resulting from eradication of the boll weevil. Because cotton acreage generally uses more pesticides than the 

corn and soybean acreage it displaced, the recent changes in crop patterns have caused a substantial increase in the quantity and 

number of pesticides applied to cropland in the basin.

Storm runoff carries much of the pesticides transported by streams draining 

cropland and suburban land. The quantities of pesticides transported are 

low relative to the quantities applied because pesticides are primarily 

retained in the soil and degraded or are transported from these watersheds 

by other pathways.

Several minor crops are grown in the 

ACF River Basin including pecans 

(shown above), peaches, melons, cucumbers, squash, tomatoes, snap beans, 

sweet peppers, and collard greens. 

About 3.2 million pounds of pesticides 

are used annually on these crops 

(Anderson and Gianessi, 1995). (Photograph is by Debbie Warner, USGS.)

MAJOR ISSUES AND FINDINGS

Pesticides in Streams

12 Water Quality in the Apalachicola–Chattahoochee–Flint River Basin, Georgia, Alabama, and Florida, 1992–95
Atrazine in the

Upper Floridan 

aquifer

(detected at 23 

of 41 sites)

0

40

10

20

30

NUMBER OF SITES WHERE ONE OR MORE

PESTICIDES WERE DETECTED

5

0

6

5

5

0 0 00

Insecticides

Nonselective herbicides

Soil fumigants

Selective preemergence herbicides

Number of compounds detected

Suburban and urban 

(detected at 23 

of 37 sites)

Forest 

(detected at 

0 of 4 sites)

5

00

3

7

4

1 1

Cropland 

(detected at 

17 of 37 sites)

Mixed

(detected at 33 

of 41 sites)

PIEDMONT COASTAL PLAIN

SURFICIAL AQUIFER

UPPER

FLORIDAN

AQUIFER

PREDOMINANT LAND USE

Measured concentrations of atrazine, 

the most commonly detected compound in the Upper Floridan aquifer, 

were far below the USEPA drinkingwater standard (Nowell and Resek, 

1994). Measured concentrations of 

dieldrin, the most commonly detected 

pesticide in shallow ground water in 

Metropolitan Atlanta, exceeded the 

USEPA Health Advisory Level at 

14 percent of sites sampled.

Pesticides were detected in ground water in each land-use study area, except for 

wells situated in mostly forested parts of the Coastal Plain. Herbicides used for 

selective preemergence weed control were most commonly detected in shallow 

ground water near cropland and in the Upper Floridan aquifer. Dieldrin, an insecticide, was the most commonly detected pesticide in shallow ground water in 

areas of suburban and urban land use. 

0.0005

5

0.001

0.01

0.1

1

CONCENTRATION, IN MICROGRAMS PER LITER

Dieldrin in

shallow ground water

in areas of suburban

and urban land use

(detected at 14

of 37 sites)

Detection limit

Median

75th percentile

Maximum value 37 Number of observations

Atrazine drinkingwater standard

 Dieldrin Health

Advisory Level

41

37

Several of the pesticides detected 

in ground-water samples are now 

banned from use (dieldrin and 1,2-

dichloropropane) or were in much 

greater use a decade or more prior to 

the sampling period (page 12). Atrazine and alachlor were commonly 

detected in surficial aquifers adjacent 

to cropland and the Upper Floridan 

aquifer, but probably were in greater 

use in the 1970’s and 1980’s (prior to 

the resurgence of cotton) when corn 

and soybeans were a large percentage 

of the planted acreage. Ground water 

and associated contaminants commonly are in the subsurface for years 

or decades between the time they 

enter the aquifers and the time they 

discharge to springs and streams. 

Because of the long residence time, 

the occurrence of pesticides in 

ground water from wells often lag 

any changes in pesticide-use patterns 

by years or occasionally decades.

samples collected several years after 

being banned is indicative of the 

compound's persistence in soils and 

ground water.

Ground-water samples collected from 

the recharge area of the Upper 

Floridan aquifer and from surficial 

aquifers located in areas of suburban 

and urban land use contained a 

broader variety of pesticides than 

samples collected from shallow 

ground water adjacent to cropland. 

Pesticides detected in these study 

areas include insecticides used for 

structural and turf insect control and 

herbicides used for selective preemergence and nonselective weed control. 

Herbicides used for selective preemergence weed control are the predominant type of pesticide present in 

ground-water samples from wells 

adjacent to cropland. Pesticides 

detected in ground-water samples 

generally have a larger potential to 

leach into ground water than many 

other currently used pesticides that 

were not detected.

From 8 to 16 pesticides were detected 

in water samples collected from each 

of the three ground-water study areas 

(Frick and Crandall, 1995; Frick, 

1997; Hippe, 1997). Pesticides were 

detected with least frequency in water 

from surficial aquifers sampled adjacent to cropland and most frequently 

in samples from springs and wells 

located in the recharge area of the 

Upper Floridan aquifer, a karst 

aquifer that is susceptible to contamination from bacteria and 

agricultural chemicals.

Pesticide concentrations in groundwater samples generally were less 

than current human health criteria for 

drinking-water safety. However, dieldrin concentrations in water samples 

collected during 1994–95 from 5 

of 37 sites in Metropolitan Atlanta 

exceeded the USEPA Health Advisory 

Level. Dieldrin had been used on 

agricultural land prior to 1975 and for 

structural termite control until 1987 

(Buell and Couch, 1995). The presence of dieldrin in ground-water 

MAJOR ISSUES AND FINDINGS

Pesticides in Ground Water

U.S. Geological Survey Circular 1164 13
Nitrogen and phosphorus are 

essential nutrients for plant life but 

when present in water at high concentrations they accelerate eutrophication of rivers and lakes. High 

concentrations of ammonia are 

toxic to aquatic life, and high 

concentrations of nitrate, primarily 

in ground water, are toxic to 

humans and other animals.

Sources of nutrients in the ACF 

River Basin include:

• Point sources: municipal and 

industrial wastewater effluent, 

and sanitary and combined 

sewer overflows. 

• Nonpoint sources: animal manure, primarily chicken litter; 

fertilizer; runoff from agricultural, urban, and suburban 

areas; septic systems; atmospheric deposition; and decomposition of organic matter.

Do not discharge into lakes or reservoirs

Discharge directly into lakes or reservoirs Detection limit

Minimum value

25th percentile

Median

75th percentile

Maximum value

30 Number of 

 observations

USEPA (1986) criteria for total phosphorus 

to control eutrophication in flowing 

rivers that:

EXPLANATION

Data collected from March 1, 1993, through September 30, 1995,

at Basic and Intensive Fixed Sites (pages 6 and 7)

Base

flow

StormflowMain

channel

Flood

plain

USEPA (1986) criteria for chronic exposure of aquatic organisms to ammonia 

depends on water temperature and pH

The land-use based design of the ACF 

River Basin NAWQA study provides 

an improved understanding of nutrient 

and suspended-sediment concentrations and yields in streams in the ACF 

River Basin. Differences in nutrient 

concentrations and yields among 

predominant land-use settings provide 

preliminary guidance for waterresource managers to focus efforts to 

control nutrients and suspended 

sediment in varying land-use settings. 

Analysis of data for the years 1972 

to 1990 from stream-water-quality 

monitoring networks provided a good 

understanding of the occurrence and 

distribution of nutrients in main-stem 

rivers and, to a lesser extent, in reservoirs and large tributaries (Frick and 

others, 1996). However, because these 

networks focused on regulatory compliance upstream from drinking-watersupply intakes and downstream from 

wastewater-treatment plant outfalls, 

some monitoring sites were affected 

by point sources that tend to mask 

land-use effects on water quality.

14 Water Quality in the Apalachicola–Chattahoochee–Flint River Basin, Georgia, Alabama, and Florida, 1992–95

MAJOR ISSUES AND FINDINGS 

Nutrients and Suspended Sediment in Streams

28 18 51 30 27 19 29 15 47 34 31 16

0.01

10

0.1

1

NITRATE

CONCENTRATION,

IN MILLIGRAMS

PER LITER AS N

28 18 51 30 27 19 29 15 47 34 31 16

0.01

10

0.1

1

AMMONIA

CONCENTRATION,

IN MILLIGRAMS

PER LITER AS N

28 18 52 30 27 19 29 15 52 35 31 16

0.006

10

0.01

0.1

1

TOTAL-PHOSPHORUS

CONCENTRATION,

IN MILLIGRAMS

PER LITER AS P 

TRIBUTARIES WITH ONE

PREDOMINANT LAND USE

26 18 37 28 25 19 27 26 38 32 25 15

1

10,000

10

100

1,000

SUSPENDED-SEDIMENT

CONCENTRATION,

IN MILLIGRAMS

PER LITER

Poultry

Suburban

Urban

Forest

 Cropland

(Clastic deposits)

Chattahoochee River

 upstream from Atlanta

 Chattahoochee River

downstream from Atlanta

 Cropland

(Carbonate bedrock)

PREDOMINANT LAND USE SITE LOCATION

PIEDMONT COASTAL

PLAIN PIEDMONT COASTALPLAIN

2232 2734

2232 2734

2232 2734

LARGE RIVERS WITH

MIXED LAND USE

1229 2654

Apalachicola River

 near mouth

Maximum Contaminant Level (USEPA 1990)

Criteria for chronic exposure of aquatic organisms

Concentrations during stormflows were significantly higher than during base flows 

for total phosphorus and suspended sediment at all tributary sites and for ammonia 

at poultry, suburban, and urban sites. Nitrate concentrations were highest in baseflow samples at the poultry site, indicating relatively high nitrate concentrations in 

ground water (page 17) that discharges to streams. Nutrient and suspendedsediment concentrations were significantly higher in the Chattahoochee River 

downstream than upstream from Atlanta. USEPA criteria for total phosphorus was 

most often exceeded during stormflow conditions at the poultry, urban, and suburban sites, and in the Chattahoochee River downstream from Atlanta. No ACF 

River Basin samples exceeded the ammonia criteria.
Yields are calculated by dividing the amount of a compound 

flowing out of a watershed by the drainage area to facilitate 

comparisons among watersheds of different sizes. Within 

the ACF River Basin, highest nitrate yields are primarily the 

result of elevated nitrate concentrations in ground water in 

the watershed characterized by poultry land use and wastewater effluent in the Chattahoochee River downstream from 

Atlanta. Highest ammonia yields are associated with discharges of untreated wastewater upstream from the urban 

site, high ammonia concentrations during stormflow upstream from the poultry site, and wastewater in the Chattahoochee River downstream from Atlanta. Highest total-phosphorus yields are primarily the result of total-phosphorus 

concentrations during stormflow at the poultry site, and 

phosphorus associated with organic detritus, rather than as 

forms that can be directly linked to fertilizer applications, at 

the cropland site (watershed underlain by clastic deposits).

Stormflow

Base flow

NITRATE YIELD, IN

POUNDS PER SQUARE

MILE PER YEAR

AMMONIA YIELD, IN

POUNDS PER SQUARE

MILE PER YEAR

TOTAL-PHOSPHORUS

YIELD, IN POUNDS PER

SQUARE MILE PER YEAR

SUSPENDED-SEDIMENT

YIELD, IN TONS PER

SQUARE MILE PER YEAR 

Main

channel

TRIBUTARIES WITH

ONE PREDOMINANT

LAND USE

LARGE RIVERS

WITH MIXED

LAND USE

5,000

4,000

3,000

2,000

1,000

0

2,500

2,000

1,500

1,000

500

0

2,000

1,500

1,000

500

0

700

600

500

400

300

200

100

0

Chattahoochee River

 upstream from Atlanta

 Chattahoochee River

downstream from Atlanta

Apalachicola River

 near mouth

Poultry

Suburban

Urban

Forest

 Cropland 

(Clastic deposits)

 Cropland

(Carbonate bedrock)

PREDOMINANT LAND USE SITE LOCATION

Flood plain

Since the early 1970's, substantial progress has been made 

toward reducing point sources 

of nutrients throughout much of 

the ACF River Basin (Frick and 

others, 1996). However, there 

are limited historical waterquality data from tributary 

streams to estimate nonpointsource inputs of nutrients from 

individual land uses. 

In streams, nutrient and suspended-sediment concentrations 

(page 14) and yields (page 15) 

are highly dependent on inputs 

from point and nonpoint sources, 

land-disturbing activities, and 

basin hydrology. The six Fixed 

Sites representing one predominant land use have no treatedwastewater outfalls upstream; 

however, there are two combined 

sewer overflows upstream from 

the urban site. During the study 

period, stormflow accounted for 

as low as 36 percent of annual 

volume of water at the poultry 

site, to as high as 82 percent at 

the urban site. Daily water 

releases from Lake Sidney 

Lanier account for much of the 

streamflow in the Chattahoochee 

River; therefore, streamflows 

were not separated into base flow 

and stormflow at sites upstream 

and downstream from Atlanta. 

Near the mouth of the Apalachicola River, approximately 40 

percent of the flow is in the flood 

plain during high river stages.

The Basic Fixed Site at which 

poultry production was the predominant land use within the 

watershed had the highest concentrations and yields of nitrate, 

total phosphorus, and suspended 

sediment and the second highest 

concentrations and yield of 

ammonia of all Fixed Sites in the 

ACF River Basin. The primary 

nutrient source within this watershed and in most of the Chattahoochee River Basin upstream 

from Lake Sidney Lanier is 

poultry litter applied as fertilizer 

to pasture land (Frick and others, 

1996). The base-flow component 

of nitrate yield at the poultry site 

is the only nutrient or suspendedsediment base-flow component 

that accounts for more than 

50 percent of the annual yield. 

Water recharging shallow 

ground water in the area is 

enriched in nitrate primarily 

from poultry litter, which in 

turn enriches nitrate concentrations in ground water, the source 

of most base flow. In contrast to 

other nutrients and suspended 

sediment in various land-use 

settings, reducing nitrate yields 

in streams in watersheds characterized by poultry land use will 

involve reducing nitrate concentrations in ground water in addition to reducing concentrations 

in runoff during stormflow. 

The predominantly urban and 

suburban sites and the Chattahoochee River downstream from 

Atlanta have relatively high 

nutrient concentrations and 

yields. Nutrient concentrations 

and yields at the suburban site 

are similar but slightly lower 

than at the urban site, with two 

exceptions. The first is that 

ammonia concentrations and 

yield are significantly lower at 

the suburban site because there 

are no combined sewer overflows. The second is that, 

although suspended-sediment 

concentrations are slightly lower 

at the suburban site, yield is 

slightly higher, probably as a 

result of more construction and 

development throughout the 

predominantly suburban watershed or construction at the sampling site, or both. High nitrate 

concentrations and yield in the 

Chattahoochee River downstream from Atlanta are primarily the result of nitrogen 

in wastewater effluent. 

U.S. Geological Survey Circular 1164 15

Data collected from March 1, 1993, through September 30, 1995, at Basic and 

Intensive Fixed Sites (pages 6 and 7). Load estimates based on computer program by Charles Crawford (USGS, written communication, 1998)

MAJOR ISSUES AND FINDINGS

Nutrients and Suspended Sediment in Streams
Although total-phosphorus concentrations of sediment deposited in reservoirs (page 21) 

throughout the ACF River Basin has increased slightly in the last half of the 20th century, 

the largest increases occurred downstream from Metropolitan Atlanta. Total-phosphorus 

concentrations of sediment in Lake Harding began declining after 1974 when West Point 

Lake was built upstream. Total-phosphorus concentrations in West Point Lake sediment 

increased until approximately 1988 when a relatively rapid decrease coincided with 

restrictions on (1) the use of phosphate detergents in Georgia, and (2) the concentration 

of phosphorus discharged by major wastewater-treatment facilities into the Chattahoochee River between Lake Sidney Lanier and West Point Lake.

Total-phosphorus loads in the Chattahoochee River downstream from Metropolitan Atlanta decreased by about 77 

percent from the highest level in 1984 

because of reductions in point-source 

loads. However, point sources continue 

to contribute a major part of the phosphorus load to the river. Between Lake 

Sidney Lanier and the upstream site 

shown in the above graph, there are 

no municipal or industrial discharges 

greater than 1 million gallons per day. 

Therefore, most of the increase in 

phosphorus loads in the Chattahoochee 

River upstream from Atlanta are from 

increasing nonpoint-source loads.

Wastewater discharge to the Chattahoochee River from the six largest 

Metropolitan Atlanta wastewatertreatment facilities increased by about 

50 percent from 1980 to 1995; however, 

the total-phosphorus load from these 

facilities decreased by about 83 percent 

from the largest load in 1988. Improved 

wastewater treatment accounts for 

about two-thirds of the decrease, and 

restrictions on phosphate detergents 

accounts for about one-third of the 

decrease (Hippe and others, 1997).

At tributary sites studied with one predominant land use, more than 60 percent of 

most nutrient yields occurs during stormflows. At the urban site, which has the 

highest percentage of impervious area in it's watershed, more than 80 percent of 

runoff and nutrient and suspended-sediment yields occur during stormflows. The 

predominance of stormflow transport is indicative of primarily nonpoint sources of 

nutrients and suspended sediment. 

1925 

1935 

1945 

1955 

1965 

1975 

1985 

1995 

0 0.25 0 0.25 0 0.25 0 0.25 0 0.25 0 0.25 0.5

CONCENTRATION OF TOTAL PHOSPHORUS IN RESERVOIR CORES,

IN PERCENTAGE OF DRY WEIGHT

Lake Sidney

Lanier

West Point

Lake

Lake

Harding

Walter F. George

Reservoir

Lake

Blackshear

Lake Seminole,

Flint arm

Dam completion

UPSTREAM

FROM ATLANTA DOWNSTREAM FROM ATLANTA

CHATTAHOOCHEE RIVER FLINT RIVER

19801982198419861988199019921994

0

100

200

300

400

TOTAL-PHOSPHORUS LOAD,

IN TONS PER YEAR

DISCHARGE, IN MILLIONS OF 

GALLONS PER DAY

PHOSPHORUS 

LOAD IN

WASTEWATER 

WASTEWATER

DISCHARGE 

Voluntary

restriction

on use of 

phosphate

detergent

Voluntary

restriction

on use of 

phosphate

detergent

Mandatory 

restriction

on use of

phosphate

detergent

Mandatory 

restriction

on use of

phosphate

detergent

Incomplete

data set 

for 1985 

1,600

1,200

800

400

0

1995

198019821984

1986

19881990199219941995

MAJOR ISSUES AND FINDINGS

Nutrients and Suspended Sediment in Streams

Percentage transported 

 during stormflow 

 conditions

21-40

41-60

61-80

81-100

ANNUAL

RUNOFF

PREDOMINANT

LAND USE, 

IN TRIBUTARIES

ANNUAL YIELD

Nitrate Ammonia Total

phosphorus

Suspended

sediment

Poultry

Suburban

Urban

Forest

Agriculture (clastic)

Agriculture (karst)

EXPLANATION

Low nutrient concentrations and yields 

at the forested and cropland sites, the 

Chattahoochee River upstream from 

Atlanta, and the Apalachicola River 

near its mouth are indicative of good 

water quality. Suspended-sediment 

concentrations at the forested site are 

similar to those at the urban site; 

however, the annual yield at the 

forested site is much lower because 

only 47 percent of the annual runoff 

occurs during stormflow compared 

with 82 percent of the annual runoff 

at the urban site. A large number of 

reservoirs upstream, relatively slow 

stream velocities, intact riparian 

vegetation in wide flood plains, long 

travel times from upstream nutrient 

and suspended-sediment sources, and 

low population densities all contribute 

to the good water quality near the 

mouth of the Apalachicola River.

High nutrient and suspended-sediment 

yields from stormflows are indicative 

of primarily nonpoint sources of 

these constituents. Thus, more 

extensive control of stormwater 

runoff from poultry production, 

suburban, and urban areas would be 

needed to significantly reduce eutrophication of lakes and reservoirs in 

the ACF River Basin.

CHATTAHOOCHEE 

RIVER UPSTREAM 

FROM ATLANTA

CHATTAHOOCHEE 

RIVER DOWNSTREAM 

FROM ATLANTA

TOTAL-PHOSPHORUS LOAD, 

IN TONS PER YEAR1,600

1,200

800

400

0

16 Water Quality in the Apalachicola–Chattahoochee–Flint River Basin, Georgia, Alabama, and Florida, 1992–95
MAJOR ISSUES AND FINDINGS

Nutrients in Ground Water

3933 81459 13

Shallow sand 

Tile drains

 aquifer

Springs

Flood-plain

 deposits

Streambed

Stream

12

0

2

4

6

8

10

NITRATE CONCENTRATION, 

IN MILLIGRAMS PER LITER

AS NITROGEN

Maximum

Contaminant

Level

0

20

5

10

15

NITRATE CONCENTRATION,

IN MILLIGRAMS PER LITER AS NITROGEN

 Poultry

Suburban 

 and urban

Cropland

Forest

Mixed (Upper 

Floridan aquifer) 

2

24

24

0

0

40 4

1

40

2

2

38

PREDOMINANT LAND USE

Upland soils in the Coastal 

Plain of the ACF River Basin 

commonly contain thick, continuous, clay layers. These clay 

layers impede the transport of 

agricultural chemicals to shallow and deeper aquifers.

Tile drains and ditch networks 

in farm fields are designed to 

drain areas where ground water 

is perched above clay layers. 

Runoff carried to streams by 

these drainage networks have 

higher concentrations of 

agricultural chemicals than (1) 

ground-water discharge from 

springs located along the edges 

of flood plains and 

(2) ground-water 

discharge to 

streams that first 

passes through 

organic-rich floodplain deposits.

Although nitrate generally is present 

in ground water in each of the landuse settings and in the Upper Floridan aquifer, concentrations only 

rarely exceed the USEPA drinkingwater standard of 10 milligrams per 

liter as nitrogen.

33 Number of 

observations

75th percentile

Median

25th percentile

Minimum value

Maximum value

Number of observations

75th percentile

Median

25th percentile

Minimum value

Maximum

Contaminant

Level

Maximum value

Sites that exceeded MCL

U.S. Geological Survey Circular 1164 17

In some areas of the Nation, prolonged 

use of fertilizers or manure for crop 

production has led to high nitrate concentrations in shallow ground water 

that renders it unsafe for consumption 

by pregnant and nursing mothers, 

young infants, and young farm animals. In major crop-producing areas 

of the ACF River Basin, however, 

clay-rich upland soils and extensive 

forested flood-plain areas may reduce 

the risk of nitrate contamination of 

ground water and streams, respectively. A ground-water flow-system 

study site with these landscape and 

soil characteristics was studied to 

characterize (1) the spatial distribution 

of ground-water quality in relation 

to subsurface conditions and (2) the 

quality of water of the predominant 

ground-water discharge zones relative 

to that of the receiving stream.

Three distinctive subsurface environments were delineated on the basis 

of nitrate concentrations and other 

chemical indicators: (1) clay-rich soil, 

(2) shallow aquifer, and (3) flood plain 

deposits (see generalized cross section). 

In the farmed upland area, nitrate was 

present in ground water both above 

and below clay-rich soil layers. However, tile drainage from above the 

restrictive soil layers has higher nitrate 

and lower dissolved-solids concentrations than water from wells screened 

in the shallow aquifer located below 

these soil layers. The clay-rich soil 

layers impede the downward flow of 

water, so agricultural chemicals that 

are applied to cropland tend to stay in 

shallow soil layers where they are used 

by crops or degraded. In water from 

wells screened in flood-plain deposits, 

nitrate was absent or present at significantly lower concentrations than in 

the upland areas. Organic-rich layers 

within flood-plain deposits rarely contained nitrate because nitrate is chemically unstable in the reducing conditions that characterize these layers.

Three ground-water discharge zones 

also were delineated: (1) tile drains 

and ditches in upland draws, (2) a line 

of intermittent and perennial springs 

at the edge of the flood plain, and 

(3) seepage zones through the bed of 

the stream channel. Tile drains and 

ditches were sustained by a perennial 

discharge of ground water derived 

locally from the shallow subsurface 

overlying restrictive clay layers. 

Ground-water flow from the shallow 

aquifer sustains a line of springs as 

well as seepage through the streambed 

to the stream; however, seepage 

through the streambed only rarely 

contained detectable nitrate. Median 

nitrate concentrations of water samples analyzed from each discharge 

zone are 7.3, 1.2, and less than 0.05 

milligrams per liter as nitrogen, 

respectively, or about 17, 2.7, and less 

than 0.10 times that of the median 

nitrate concentration of the receiving 

stream. Nitrate loadings from tile 

drains are very high relative to their 

discharge volumes, and where tile 

drains are present they represent an 

important pathway for transport of 

nitrate and other agricultural chemicals to streams during base-flow 

conditions (ground-water discharge) 

and during periods of storm runoff.

Clay-rich soil

Shallow sand aquifer

Confining layer

Flood-plain

deposits

Upland

Flood plain

Slope

Tile drains

Springs Stream

NOT TO SCALE
Industry As Cd Hg Cu Pb Zn Phenols

Phthalates PAHs

Food preparation 5 44 33

Textiles 300 0 4 9 24 2 11

Lumber and wood 65

48

65 20 18 6930000

Paper products 800000 5 31 81

Chemicals 6 1 5 46 28 86 54 55 45

Petroleum and coal 4 3 9 11 000 72 0

Rubber and plastics 1 6 1 3 12 47 4 5 28

Stone, clay, glass 3000 6 10 12 49 6

Metal products 6 011

11

109

1,200

95

960

93 185

4,900 4,500 4,400 1,600

21 28 4

Industrial machinery 11 16600 0 512 2

Electronics 3 0 00 3

41

83 21 332 192 328 142 165 1109

31 25 6015 6

Transportation equipment

Total emission 1987-93,

 in thousands of pounds

Total facilities

0 7 10 13 13 13 200

Total1

metals

12

48

121

59

7,200

630

29

31

35

9

16

40

5

6

Total1

organics

36

0000000

123

37

10,500

357

19

Facilities reporting releases of metals and organics to the atmosphere within 300 miles 

of Albany, Georgia, from 1987 to 1993. Data from: http://www.epa.gov/opptintr/tri

TRACE ELEMENTS ORGANICS

1 The totals may not equal the sum of the parts because a particular industry may emit more than one trace element 

 or organic compound.

Spatial surveys of bed and bottom 

sediments in rivers, reservoirs, and 

wetlands of the ACF River Basin were 

performed (see maps on pages 26–27) 

to determine the extent of environmental contamination by trace 

elements (mostly heavy metals) and 

synthetic organic compounds. Samples 

from 48 sites were analyzed to compare contaminant concentrations in the 

recently deposited sediments of watersheds with different predominant land 

uses and hydrogeology. Contaminant 

concentrations also were compared to 

quantities of the contaminants released 

to the atmosphere from permitted 

facilities located within and around 

the Study Unit. Twenty-one sites are 

located on main-stem rivers or reservoirs, five sites are on large tributaries 

to the Flint River, and 22 sites are on 

streams draining smaller watersheds 

with a predominant land use.

The largest trace-element enrichment 

(summarized in illustration on page 

19) was in (1) urban and suburban 

watersheds draining portions of 

Metropolitan Atlanta and Columbus, 

(2) main-stem and reservoir settings 

on the Chattahoochee River downstream from Atlanta, and (3) the Flint 

River downstream from Albany. Some 

exceptions to this pattern are evident, 

including: (1) copper enrichment 

throughout the Piedmont, (2) mercury 

and lead enrichment in small forested 

watersheds in the Coastal Plain, 

(3) mercury and copper enrichment 

in the Chattahoochee River upstream 

from Atlanta, and (4) cadmium and 

mercury enrichment in the large 

Coastal Plain tributaries to the 

Flint River. 

Much of the transport and deposition 

of trace-element contaminants to 

receiving watersheds may occur along 

regional atmospheric pathways. However, urban landscapes with high 

percentages of impervious areas, such 

as industrial and transportation areas, 

enhance the movement of airborne 

trace elements to waterways. 

Regional transport of trace elements and organic compounds

SOURCES AND TRANSPORT OF TRACE ELEMENTS AND ORGANIC COMPOUNDS

Air emissions from 

industrial facilities 

inside and outside of 

the watershed are a 

major source of 

trace elements and 

organic compounds.

Suburban and urban areas 

contain additional nonpoint 

sources of trace elements 

and organic compounds. 

Impervious surfaces collect 

pollutants, and storm runoff 

delivers them to area streams.

Forest and agricultural 

land have few local 

sources of trace elements 

and organic compounds. 

Most deposited contaminants are retained in soils 

rather than being transported to streams.

MAJOR ISSUES AND FINDINGS

Trace Elements and Organic Compounds in Bed Sediment

Toxic Release Inventory (TRI) release-to-air data for industrial facilities within 300 miles 

of Albany, Georgia, are summarized for the years 1987–93 for six toxic trace elements 

and three categories of organic compounds that are toxic, carcinogenic, or both. The 

300-mile-radius airshed was conservatively chosen as a potential contributing area to 

the ACF River Basin. Releases to air of arsenic, cadmium, mercury, copper, lead, and 

zinc were reported for 630 facilities representing 12 industrial categories. Copper, lead, 

and zinc accounted for 99 percent of the total load of 7.2 million pounds during 1987–93, 

whereas arsenic, cadmium, and mercury accounted for only 1 percent of that load. 

Polycyclic aromatic hydrocarbons (PAHs), phenols, and phthalates accounted for the 

release of 10.5 million pounds of organic compounds by 357 facilities during 1987–93. 

Exposure to high concentrations of trace elements and organic compounds in aquatic 

sediments are a health risk both to the aquatic life and terrestrial animals (including 

people) that consume food resources taken from our waterways. Although soils and 

rocks contain low concentrations of most trace elements, much of the current pollutant 

load of these contaminants is derived from industrial emissions and urban nonpoint 

sources. The dominant pathways involve regional atmospheric transport and 

deposition on land. Urban land areas have high percentages of impervious surfaces 

that collect pollutants and storm drains that carry pollutants to nearby streams.

18 Water Quality in the Apalachicola–Chattahoochee–Flint River Basin, Georgia, Alabama, and Florida, 1992–95
Arsenic

Number

of sites

Cadmium

Mercury

Copper

Lead

Zinc

6

.3

.04

17

22

85

18

5.6

2.3

3.8

.5

<.1

.56

.08

.04

420

29

11

360

38

17

1700

130

73

9.35

.16

<.01

1.83

.05

<.01

1.34

.05

<.01

.010

.003

<.001

.010

.001

<.001

15 6 2 24 333 352 7

TRACE-ELEMENT CONCENTRATIONS

RELATIVE TO BACKGROUND

PIEDMONT

 Small basins

COASTAL PLAIN

 Small basins

CHATTAHOOCHEE RIVER

 Main stem and reservoirs

FLINT RIVER

 Main stem, reservoirs, 

 and large tributaries

APALACHICOLA RIVER

 Main stem, flood plain, 

 and large tributaries

Background

(Applies

only to 

trace

elements)

Maximum

Median

Minimum

PAHs

Phthalates

Phenols

Chlordane

DDT

 Poultry

Suburban

Urban

Forest

Forest

Cropland

 Upstream from Atlanta

 Downstream from Atlanta

 Downstream from Atlanta

 Downstream from Albany

 Large tributaries

 Downstream from Columbus

ORGANIC COMPOUND

CONCENTRATIONS RELATIVE 

TO THE SAMPLE MEDIAN

PREDOMINANT LAND USE

U.S. Geological Survey Circular 1164 19

SITE LOCATION

An Index of Geoaccumulation (Muller, 1979) 

was developed for the toxic trace elements 

arsenic, cadmium, mercury, copper, lead, and 

zinc and the results are shown here as circles 

with different diameters. The smallest circle 

represents index values of zero (no enrichment 

relative to background), and each increase in 

circle diameter represents up to twice the enrichment of the previous level. The Index 

of Geoaccumulation was modified slightly for organic compounds so that the variations 

in circle diameter represent positive departures from the median compound concentrations for the data set. Organic-compound concentrations that are equal to the 

median of the data set are shown at the smallest circle diameter; each increase in 

circle diameter is equal to concentrations twice that of the previous level. No circle is 

shown for locations where organic compounds were not detected. For trace elements, 

the maximum, median, minimum, and background concentrations are reported in 

micrograms per gram. For organic compounds, the maximum, median, and minimum 

concentrations are reported in micrograms per kilogram.

Bed-sediment samples are sieved and 

the silt and clay fractions are analyzed 

to minimize effects of grain size on patterns in trace-element chemistry.

 ̈

Among organic compounds present 

in streambed sediments, polycyclic 

aromatic hydrocarbons (PAHs) and 

phthalates were at highest concentrations in (1) suburban and urban 

watersheds in Metropolitan Atlanta 

and Columbus, (2) main-stem reaches 

of the Chattahoochee River downstream from Atlanta and Columbus, 

and (3) the Flint River downstream 

from Albany. Unlike the trace elements that naturally occur at background concentrations in most soils 

and sediments, PAHs and phthalates 

are present in sediments as contaminants from industrial activity, fossilfuel combustion, or waste incineration. 

PAHs are released from wood and 

other plant material by fires. Phthalates are used for production of plastics 

and plastic products. Phenols have 

many industrial and natural sources 

and are widely distributed in sediments of the ACF River Basin.

Although most organochlorine insecticides such as chlordane and DDT have 

been banned from use, residual quantities of these compounds and their 

degradation products are common in 

the sediments of the ACF River Basin. 

Chlordane and DDT were at highest 

concentrations in urban watersheds of 

Atlanta and Columbus, but also were 

present in watersheds draining cropland and in main-stem and reservoir 

sites. Chlordane was used as an insecticide on cropland until the mid-1970's 

and for building and foundation proMAJOR ISSUES AND FINDINGS

Trace Elements and Organic Compounds in Bed Sediment

tection against termite damage until 

the late 1980's. DDT was used through

the early 1970's as an insecticide, both 

in agricultural and urban settings. 

None x2 x4 x8 x16 x32

Magnitude of enrichment

EXPLANATION
ADJUSTED TRACE-ELEMENT

CONCENTRATIONS*

PERCENTAGE OF INDUSTRIAL AND TRANSPORTATION

LAND USE IN SAMPLED WATERSHED

0 5 10 15 20

10

1

0.1

0.01 0 5 10 15 20

1,000

100

10

Although much of the transport of 

airborne pollutants is regional, stormwater runoff from impervious areas is 

a major factor in increasing traceelement concentrations in receiving 

streams. Concentrations of mercury, 

cadmium, lead, and zinc in the streambed sediments of suburban and urban 

watersheds in Metropolitan Atlanta 

and Columbus increased in direct 

proportion to the percentage of industrial transportation land use in these 

watersheds. This direct response likely 

is the result of deposition of emissions 

from regional and local sources on 

impervious surfaces and subsequent 

transport of these pollutants in 

stormwater runoff to streams.

MAJOR ISSUES AND FINDINGS

Trace Elements and Organic Compounds in Bed Sediment

20 Water Quality in the Apalachicola–Chattahoochee–Flint River Basin, Georgia, Alabama, and Florida, 1992–95

Lead Zinc

Suburban

Urban

CadmiumMercury

Trace elements

Land use

EXPLANATION

*Trace-element concentrations are adjusted for organic 

carbon and titanium to minimize effects of varying grain size

Stormwater runoff from impervious 

areas in Metropolitan Atlanta and 

Columbus is a significant factor in 

delivering metals to streams, as 

indicated by increasing adjusted 

concentrations of mercury, cadmium, lead, and zinc with increasing 

percentages of industrial transportation land use in these watersheds.

Urban areas have additional local sources of trace elements and organic compounds. The USEPA Toxic Release Inventory (TRI) 

data base (http://www.epa.gov/opptintr/tri) contains annual emissions to air, land, and water of more than 600 toxic chemicals. 

Industries and Federal facilities that either manufacture more than 25,000 pounds of, or use more than 10,000 pounds of, any 

designated chemical per year are required to report their releases. Currently, reported releases to water are minimal and releases to 

land are to landfills or other secured areas with low potential for transport to waterways. Therefore, releases to air provide the best 

available estimate of trace-element and organic-compound inputs for regional assessments. However, smaller industrial producers 

and users of trace elements and organic compounds, wastewater-treatment plants, and coal- and oil-burning power plants do not 

contribute emissions information to the TRI data base. Also, the quantities of local inputs of trace elements and organic compounds 

from nonpoint sources, such as automobile emissions and litter and debris disposed along roadways and streams, are not known. 

(Photograph of power plant is by Steve Kandell, Atlanta Regional Commission.)

Wastewater-treatment plant Coal-burning power plant Litter and debris in an urban stream
MAJOR ISSUES AND FINDINGS

Historical Trends in Water Quality Determined from Reservoir Cores

In 1994, six reservoirs located in the 

ACF River Basin were selected for 

sediment coring as part of a NAWQA 

pilot program designed to relate effects 

of land-use changes through time to 

historical water quality of the impounded watersheds. The reservoirs 

sampled are situated along the main 

stems of the Chattahoochee and Flint 

Rivers. Their watersheds have different predominant land uses and dates 

of dam completion. Thus, not only can 

the temporal history of the age-dated 

cores be related to historical land-use 

changes, but the effects of upstream 

impoundments on the sediment 

chemistry in older reservoirs located 

downstream can be used to infer the 

source areas for selected pollutants. 

Sediment cores were collected and 

age-dated by methods described in 

Van Metre and others (1997) and 

analyzed for organochlorine compounds and trace elements. The years 

1952 and 1963–64 were assigned to 

depths in sediment cores from the 

four older reservoirs on the basis of 

patterns in radioactive cesium (137Cs) 

concentrations; higher concentrations 

correspond to past periods of aboveground hydrogen-bomb testing. 

Ages of dam completion were 

assigned to cores from all the reservoirs (except Lake Harding) by 

locating transitions between stream 

and reservoir sediments.

U.S. Geological Survey Circular 1164 21

Reservoirs are efficient sediment 

traps. Sediments deposited in a 

reservoir retain a physical and 

chemical history of the effects of 

human activities on the reservoir 

watershed. Detailed analysis of 

sediment cores collected from 

reservoirs allow scientists to reconstruct historical trends in streamwater quality. When accompanied 

by historic patterns of urban growth, 

industrial activity, and agricultural 

land-use, the results of this synthesis 

provide an invaluable tool for longterm environmental assessment.

Six major reservoirs in the ACF River Basin were used 

to evaluate historical trends in water quality. Lake 

Sidney Lanier, which is on the Chattahoochee River 

about 45 miles upstream from Atlanta, was impounded 

by the U.S. Army Corps of Engineers (Corps) in 1956, 

primarily for flood control and hydropower generation. 

Although the predominant land uses are forest and 

pasture, much of the pasture land is used for the 

disposal of chicken litter. Urban growth in the Lake 

Sidney Lanier watershed has increased pollutant loads 

to the reservoir, as has extensive land clearing for 

subdivisions in rapidly developing suburban settings. 

West Point Lake was constructed by the Corps in 

1974 and is located approximately 60 miles downstream from Atlanta. Urban and suburban growth in 

the Metropolitan Atlanta area accelerated beginning in 

the late 1970's and has continued at a rapid pace to 

the present. 

Lake Harding, on the Chattahoochee River downstream from Atlanta (105 miles) and upstream from 

Columbus (18 miles), is the oldest reservoir of the six 

ACF reservoirs studied. Georgia Power Company 

constructed the Lake Harding dam in 1926 for 

hydropower generation. 

The Chattahoochee River is a navigable waterway 

from Columbus downstream to Lake Seminole. Part of 

this navigation channel includes Walter F. George 

Reservoir, located approximately 35 miles downstream from Columbus and constructed by the Corps in 1963 for flood control, hydropower 

generation, and navigation. Although the surrounding land largely is forested with some 

cropland and pasture, the urban influence of Columbus also affects the water quality and 

sediment chemistry of this reservoir.

Lake Blackshear, the first impoundment on the Flint River, is almost 200 miles downstream from the Flint River's headwaters at Atlanta's Hartsfield International Airport. This 

reservoir was filled in 1927 upon completion of Warwick Dam by the Crisp County Power 

Commission. Although the Flint River watershed begins in Atlanta, Lake Blackshear's 

water quality is little affected by urban land use. The Piedmont portion of the Lake 

Blackshear watershed largely is a patchwork of forest, cropland, and pasture; the Coastal 

Plain portion is predominantly cropland and pecan groves. However, extensive wetland 

riparian buffers intercept runoff along most of the Coastal Plain reach of the Flint River, 

thus mitigating the impact of agriculture on the reservoir's water quality.

The terminal reaches of both the Chattahoochee and Flint Rivers are impounded behind 

Jim Woodruff Dam, completed in 1954 by the Corps to form Lake Seminole, approximately 133 miles downstream from Columbus and 74 miles downstream from Albany. 

Bainbridge is located on the Flint River arm of the reservoir. Lake Seminole is used for 

flood control, hydropower generation, and navigation. Although much of Lake Seminole's 

watershed is predominantly cropland, the land area adjacent to the reservoir largely is 

forested. There is some urban influence on the water quality of the Flint arm from Albany 

and Bainbridge.

Columbus

Atlanta

Albany

Bainbridge

West Point

Lake

Flint R

Walter F

 George

Reservoir

Apalachicola R Lake

Seminole

Lake

Blackshear

Lake

Harding

Chattahoochee R

 Lake

 Sidney

Lanier

BLUE 

RIDGE

PIEDMONT 

COASTAL PLAIN

CORE

THICKNESS,

IN INCHES

PREDOMINANT

LAND USE

SEDIMENTATION

RATE, IN INCHES

PER YEAR1

RESERVOIR

(YEAR COMPLETED)

8.7Forested, poultry

Urban

Urban

Urban

Cropland

Cropland

27.6

88.6

58.3

27.6

38.6

0.22

1.41

1.35

1.82

0.41

0.96

West Point Lake (1974)

Lake Sidney Lanier (1956)—

 Chattahoochee River arm 

Lake Harding2 (1926)

Walter F. George Reservoir (1962)

Lake Blackshear (1927)

Lake Seminole (1954)—Flint River arm 

1 Sedimentation rates are assumed to be linear and are based on core length (not dry mass of deposited material).

2 Pre-reservoir surface was not reached in Lake Harding. An age was assigned to the bottom of the core on the basis 

 of the deposition rate for the 1952 to 1963–64 core interval.
West Point Lake Lake Sidney Lanier Lake

Harding Walter F. George Reservoir Lake Blackshear Lake Seminole, Flint arm

DOWNSTREAM

FROM ATLANTA UPSTREAM

FROM ATLANTA

CHATTAHOOCHEE RIVER FLINT RIVER

ATMOSPHERIC

LEAD INPUTS

RELATIVE

UNITS

1925 

1935 

1945 

1955 

1965 

1975 

1985 

1995 

0 2,000 4,000

Dam completion

1925 

1935 

1945 

1955 

1965 

1975 

1985 

1995 

0 150 0 150 0 150 0 150 0 150 0 150 300

Dam completion

CONCENTRATIONS IN RESERVOIR CORES, IN MICROGRAMS PER KILOGRAM

Lead in cores

Lead in 

 atmosphere

Zinc

Chromium

Copper

DOWNSTREAM

FROM

COLUMBUS

UPSTREAM

FROM

ALBANY

DOWNSTREAM

FROM

ALBANY

EXPLANATION

Trace elements

MAJOR ISSUES AND FINDINGS

Historical Trends in Water Quality Determined from Reservoir Cores

22 Water Quality in the Apalachicola–Chattahoochee–Flint River Basin, Georgia, Alabama, and Florida, 1992–95

Age-dated depth profiles of lead, zinc, 

chromium, and copper concentrations 

in sediment cores show historical 

patterns of upstream urban and industrial activity, upstream reservoir construction, and regional atmospheric 

deposition. West Point Lake, Lake 

Harding, and Walter F. George Reservoir reveal a more complex history of 

trace-element pollution because they 

are most directly affected by upstream 

urban and industrial activities. 

In Lake Harding sediments, lead and 

zinc concentrations began to increase 

beginning in the mid-1940's and more 

than doubled by the mid-1970's. Copper concentrations gradually increased 

through this same period. However, 

chromium concentrations peaked 

about 1945, during the mid-1950's, 

and again during the mid-1970's, with 

the highest concentrations measured 

during this latter period. Although 

industrial growth and development in 

Metropolitan Atlanta is a source for 

much of the increased deposition of 

metals to Lake Harding, additional 

emissions outside the ACF River 

Basin also contributed through 

regional atmospheric transport and 

deposition. Concentrations of all four 

metals generally decreased between 

the mid-1970's and the time the cores 

were collected in 1994. This recent 

trend coincides with the completion 

of West Point Dam and provides evidence that, with the exception of chromium, much of the pollutant load to 

Lake Harding prior to West Point's 

completion was derived from Metropolitan Atlanta.

Chromium concentrations in Lake 

Harding and Walter F. George Reservoir cores were the highest among the 

six reservoirs sampled. Concentrations 

in the Walter F. George core peaked 

during the late 1960's and again during 

the mid-1970's and then decreased in 

similar fashion to the pattern described 

for Lake Harding. However, concentrations of chromium in post-1975 

sediments in both of these reservoirs 

are larger than those measured in West 

particularly true for lead. Leaded 

gasoline use peaked in 1972 and then 

declined through 1982 when lead 

compounds were banned from use in 

all new vehicles sold in the United 

States. This trend is shown by atmospheric lead inputs (Eisenreich and 

others, 1986) and in the reservoir 

cores, particularly West Point Lake 

and Lake Harding. The largest lead 

concentrations in reservoir sediments 

and the steepest lead declines are seen 

in the reservoirs closest to urban areas 

or with urban land areas upstream 

(Callender and Van Metre, 1997).

Lake Sidney Lanier, Lake Blackshear, 

and Lake Seminole, in contrast with 

the urban reservoirs, are less directly 

affected by local sources of pollutants. 

Historical trends in trace-element 

concentrations in these reservoirs 

largely relate to changes in the regional patterns of atmospheric deposition.

Point Lake, indicating that local 

sources downstream from Atlanta are 

contributing part of the chromium 

load. Industrial effluent from the 

textile industry has been a major 

source of chromium (Förstner and 

Wittman, 1979), and there are several 

textile mills that discharge to the 

Chattahoochee River just upstream 

from Lake Harding and Walter F. 

George Reservoir.

Except for zinc in West Point Lake 

and zinc and copper in Walter F. 

George Reservoir, trace-element concentrations generally decreased after 

1975 in all three urban reservoirs. The 

Clean Air and Clean Water Act legislation, requiring improved waste 

treatment and reduction strategies, 

were enacted about this time. Thus, 

some of the decrease in trace-element 

deposition to these reservoirs relates 

to compliance with these laws. This is 

Sediments in reservoirs located downstream from urban areas reveal a more complex 

history of trace-element deposition and generally higher concentrations than sediments 

in reservoirs with primarily rural land uses. Changes in lead concentrations in sediment 

cores closely track historical lead inputs to the atmosphere.
1925 

1935 

1945 

1955 

1965 

1975 

1985 

1995 

1 10 100 1 10 100 1 10 100 1 10 100 1 10 100 1,000

Dam completion

West Point

Lake

Lake

Harding

Walter F. George

Reservoir

Lake

Blackshear

Lake Seminole,

Flint arm

DOWNSTREAM

FROM

COLUMBUS

UPSTREAM

FROM

ALBANY

DOWNSTREAM

FROM

ALBANY

DOWNSTREAM

FROM ATLANTA

CHATTAHOOCHEE RIVER FLINT RIVER

CONCENTRATIONS IN RESERVOIR CORES,

IN MICROGRAMS PER KILOGRAM OF DRY WEIGHT

Although organochlorine-pesticide and 

PCB concentrations in reservoirs sediments have declined significantly since 

being banned, they continue to be present in sediments deposited as recently 

as 1994. Concentrations of chlordane 

and PCBs in some fish species in the 

Chattahoochee River downstream from 

Metropolitan Atlanta currently exceed safe levels for human consumption 

(Georgia Department of Natural Resources, 1997). The slow rate of decline of 

chlordane and PCB concentrations in sediments deposited in West Point Lake 

indicate that these fish-consumption advisories may continue into the future.

MAJOR ISSUES AND FINDINGS

Historical Trends in Water Quality Determined from Reservoir Cores

Sediment cores were analyzed for 

organochlorine insecticides, polychlorinated naphthalenes (PCNs), and 

polychlorinated biphenyls (PCBs). 

The only compounds detected in the 

cores were chlordane, DDT and its 

degradation products (DDD and 

DDE), and PCBs. Historical patterns 

in reservoir sediment concentrations 

of these compounds provide a record 

of changes in their use in urban and 

agricultural settings within the ACF 

River Basin.

Chlordane was extensively used 

through the late 1980's as a termiticide. Measurable concentrations of 

chlordane in the Lake Harding core 

first occurred during the early 1940's, 

indicating that chlordane use in Metropolitan Atlanta began shortly after it 

was first produced as an insecticide. 

Chlordane concentrations in Lake 

Harding sediments increased through 

the early 1950's, remained at their 

highest levels through the early 

1970's, and then decreased by about a 

factor of 10 between the mid-1980's 

and the time of sampling. Although 

use of chlordane was banned in 1988, 

the decrease in the recent section of 

core from Lake Harding probably is 

related more to the completion of 

West Point Dam and subsequent 

trapping of chlordane-contaminated 

sediments in West Point Lake. This 

interpretation is consistent with 

chlordane concentrations in the West 

Point Lake core being larger than 

post-1975 concentrations in the Lake 

Harding core. The Walter F. George 

Reservoir core had smaller but still 

measurable concentrations of chlordane, indicating that chlordane was 

also used in the Columbus area. Sale 

of chlordane for agricultural use 

ceased in 1974, and only one sample 

from Lake Blackshear and no samples 

from Lake Seminole had detectable 

concentrations of chlordane.

DDT was widely used throughout the 

ACF River Basin as an insecticide in 

urban and agricultural settings until its 

use was banned in 1973. Based on 

historical patterns in the cores 

(excluding West Point Lake), it 

appears that urban and agricultural 

use of DDT peaked in the early 1950's 

and late 1960's, respectively. However, DDT continues to be deposited 

at similar concentrations in each of 

the reservoirs.

PCBs were first commercially produced in 1929 and widely used in 

transformers, capacitors, and electromagnets and as heat-transfer and 

hydraulic fluids until their manufacture was banned in 1979. PCB concentrations in the Lake Harding core 

began to increase shortly after the 

reservoir was created, reached maximum levels during the late 1940's 

through the late 1960's, and then 

decreased to much lower concenrations by the mid-1980's. The largest 

PCB concentration in the West Point 

U.S. Geological Survey Circular 1164 23

Lake core occurred about 1976. 

Concentrations in more recent sections of the core were approximately 

one-third of the maximum, indicating 

that PCB use was prevalent in Metropolitan Atlanta up to the time of the 

ban. Concentrations of PCBs in the 

Walter F. George Reservoir core 

decreased during the late 1970's. The 

patterns in these three urban reservoirs 

could be due to a combination of local 

sources and regional atmospheric 

transport. One of the two facilities that 

manufactured PCBs in the United 

States was located in Anniston, 

Alabama, to the northwest of these 

reservoirs. Historical patterns in the 

much smaller concentrations measured 

in the Lake Blackshear and Lake 

Seminole cores probably relate to 

regional patterns in atmospheric 

transport and deposition of PCBs. Organic compounds

Chlordane

Sum DDT 

Total PCBs

Detected Not detected

Concentration

EXPLANATION
Poultry

Suburban

Urban

Forest

10

35

15

20

25

30

FISH INDEX OF BIOTIC INTEGRITY (IBI)

0

12

2

4

6

8

10

MACROINVERTEBRATE STATUS (EPT)

IBI EPT

PREDOMINANT LAND USE 

In the Piedmont Physiographic 

Province of ACF River Basin, 

stream biological communities 

are most degraded in areas of 

suburban and urban land use. 

Fish communities show the most 

degradation in streams draining 

areas of urban land use, whereas macroinvertebrate communities are degraded in streams 

draining areas of suburban and 

urban land use. 

MAJOR ISSUES AND FINDINGS

Biological Indicators of Water Quality

Aquatic biological communities commonly are sensitive indicators of streamwater quality. In highly populated areas, evaluations of aquatic biological 

communities commonly are the only assessment approach that can account 

for (1) highly transient water-quality problems stemming from urban runoff, 

accidental spills, or periodic sewer overflows, and (2) the cumulative effects of 

a potentially wide range of chemical contaminants.

The biological condition of streams is evaluated within water-quality assessment programs by comparing the type, number, or abundance of species that 

comprise aquatic biological communities to that of streams known to be 

pristine or to be least influenced by human activities. In this study, the biological condition of streams was measured using fish and benthic macroinvertebrate (adult and larval insects, crustaceans) communities in stream reaches 

representing predominant land uses in the watershed.

Two separate indices were used. The first index, an Index of Biotic Integrity

(IBI), is based on fish community data. IBI scores for a given stream were 

derived by summing scores of several separate factors that describe fish 

communities (DeVivo and others, 1997). Examples of such factors are the 

number of insect-eating and omnivorous (generalized-feeding) fish, the 

number of native sucker and minnow species, and the number of non-native 

species. The second index, an EPT Index, is based on the abundance of 

selected orders of pollution-sensitive insect larvae. It is the sum of the number 

of families within the insect orders of mayflies (Ephemeroptera), stoneflies 

(Plecoptera), and caddisflies (Trichoptera) found in a stream reach. Streams 

with higher IBI and EPT index scores are indicative of better biological 

conditions than streams with lower scores.

In the Piedmont Province, poultry 

production, suburban and urban land 

uses, and silviculture are human activities that influence the water quality of 

tributaries to the Chattahoochee and 

Flint Rivers. The biological condition 

of these tributaries are influenced by 

water-quality and hydrologic conditions that vary, depending on the type 

and intensity of human activities. 

Forested watersheds in the ACF River 

Basin are subject to less human activities than the other land uses studied, 

and although not pristine, the biological condition in streams draining 

forested watersheds may be the best 

attainable in the ACF River Basin.

Tributaries of the Chattahoochee River 

in the Piedmont are inhabited by 42 

native and 8 non-native (introduced) 

fish species (Couch and others, 1995). 

Because fish distribute themselves in 

streams relative to the location of their 

preferred habitats, not all 50 species 

live in any one stream reach. In 

streams with forested watersheds, 

about 20 fish species may live in a 

typical stream reach. In comparison 

to streams draining watersheds with 

predominantly poultry, suburban, or 

urban land use, streams with forested 

land use had the best biological condition as shown by the Index of Biotic 

Integrity (IBI, described above). 

Although streams in predominantly 

forested watersheds are periodically 

disturbed by timber harvesting, these 

watersheds do not have high yields of 

nutrients or sediments (page 15) that 

influence biological conditions by 

altering stream habitats or food 

resources and do not contain the wide 

range of chemical and microbial contaminants present in streams draining 

predominantly suburban and urban 

watersheds (page 10). IBI scores 

indicate a similar level of degraded 

biological conditions for steams draining watersheds with predominantly 

poultry and suburban land use. 

Streams draining watersheds with 

predominantly urban land use had severely degraded biological conditions. 

The macroinvertebrate status of 

streams draining watersheds with 

predominantly forested and poultry 

land use were relatively high as measured by the EPT Index (described 

above) scores, indicating markedly 

better biological conditions in these 

streams than in streams draining 

watersheds with predominantly 

suburban or urban land use. Poor 

habitat, high stormflows, and the 

presence of chemical contaminants, 

such as insecticides, may contribute 

to the loss of pollution-intolerant 

insect species in the streams draining 

watersheds with predominantly 

suburban and urban land use. The 

higher EPT Index scores in streams 

draining watersheds with predominately poultry land use may be 

related to high nutrient inputs that 

increase the availability or variety of 

food resources beyond what is present in streams draining watersheds 

with predominantly forested land use.

24 Water Quality in the Apalachicola–Chattahoochee–Flint River Basin, Georgia, Alabama, and Florida, 1992–95
40

35

30

25

20

15

10

5

0

0 100 200 300 400 500 600

WATERSHED POPULATION,

 PER SQUARE MILE

FISH IBI SCORE

Developed suburban/

urban watersheds 

Forested watersheds

Undergoing suburban/urban

 development

FAIR

TO

GOOD

POOR

In the Piedmont, fish communities 

are degraded by increasing urban 

development. In forested watersheds, streams have fish communities that are represented by a 

diversity of mostly native species 

with varied tolerance to pollution. 

As watersheds are developed, fish 

communities in streams are dominated by pollution-tolerant, mostly 

non-native species.

Lime Creek watershed and other 

watersheds in the Coastal Plain of the 

ACF River Basin have broad, forested 

flood plains that separate streams 

from farmed upland areas. These 

relatively undisturbed flood plains 

have an important role in maintaining 

stream-water quality and the integrity 

of aquatic biological communities in 

areas that otherwise are extensively 

used for cropland.

MAJOR ISSUES AND FINDINGS

Biological Indicators of Water Quality

As the human population of Metropolitan Atlanta continues to increase, 

forest and pasture land is being 

developed for suburban or urban use. 

Fish IBI scores for 21 tributaries of 

the Chattahoochee River that varied 

in the extent of urban development 

as measured by human population 

density show an immediate decline in 

biological condition with the onset of 

suburban and urban development 

(DeVivo and others, 1997).

Watersheds with higher population 

densities generally had lower fish IBI 

scores, indicating poorer biological 

condition. Streams in areas of predominantly suburban or urban land 

use generally had less than one-half 

the number of fish species present in 

streams in areas of predominantly 

forested land use, and as many as 90 

percent of the fish in urban streams 

were introduced. Species that survive 

outside of their native streams often 

thrive where water quality or habitat is 

degraded. Native minnow and sucker 

species were all but absent in urban 

streams. Minnows are important in the 

aquatic food chain as prey for larger

fish, aquatic snakes, turtles, and 

wading birds. Although suckers are 

not popular game fish, they are 

ecologically important because they 

often account for the largest fish biomass in healthy Piedmont streams. 

Streams draining urban lands in 

Metropolitan Atlanta contain elevated 

concentrations of nutrients (page 14) 

and a variety of chemical contaminants 

such as pesticides and trace elements 

(pages 10–11 and 19). Periodic discharges from combined sewers or 

broken or clogged sanitary sewers 

carry additional chemical and microbial contaminants into nearby streams. 

However, most nutrients and chemical 

contaminants enter streams as storm 

runoff from impervious surfaces 

(streets, parking lots) or as groundwater discharge that has percolated 

through landscaped areas. The 

degraded biological condition of 

urban streams results from the cumulative effects of high stormflows and 

exposure to a variety of contaminants. 

The Coastal Plain of the ACF River 

Basin is composed of cropland and 

silvicultural land in upland areas and 

extensive and continuous forested 

wetlands in river bottoms. Relatively 

undisturbed riparian flood-plain and 

wetland habitats are present throughout this area. This contrasts to many 

other intensively farmed areas of the 

Nation where wetlands have been 

drained, channelized, or filled, and 

little or no riparian buffers remain 

between cropland and streams.

Flood-plain wetlands provide many 

ecological benefits such as dissipating 

the energy of floods, reducing erosion, 

and stabilizing the streamside environment. Winter and spring flooding is a 

normal occurrence in Coastal Plain 

streams, and many fish species use the 

flood plains as spawning, nursery, and 

foraging areas. 

In July 1994, flooding from Tropical 

Storm Alberto resulted in streamflows 

that exceeded the 100-year recurrence 

interval throughout the Flint River 

Basin (page 9). The flood occurred 

outside of the normal period of seasonal flooding. The ACF River Basin 

NAWQA investigated the influence of 

this flood on the fish community of 

Lime Creek, a stream located in the 

area that received a large amount of 

rainfall from Tropical Storm Alberto. 

The fish-community surveys were 

performed before the flood and for a 

2-year period after the flood. 

Thirty-two fish species were identified 

during the sampling period. Although 

an IBI has not been developed for 

Coastal Plain fish communities, the 

number and diversity of fish species 

in Lime Creek indicate a healthy fish 

community. The flood did not result in 

a catastrophic loss of fish species. All 

but one fish species present in Lime 

Creek before the flood were also 

present after the flood. The potential 

disturbance to the fish community 

was lessened by the forested floodplain wetlands that remain intact in 

a watershed that is otherwise predominately cropland.

U.S. Geological Survey Circular 1164 25

Cropland

Forest

Young planted pine

Forested wetlands

Water

Lime Creek

EXPLANATION

Land use
EXPLANATION

Ranking of stream quality relative to 

 all NAWQA stream sites—Darker 

 colored circles generally indicate 

 poorer quality. Bold outline of circle 

 indicates one or more aquatic life 

 criteria were exceeded.

 Greater than the 75th percentile 

 (among the highest 25 percent of 

 NAWQA stream water studies)

Between the median and the 

 75th percentile

Between the 25th percentile 

 and the median

Less than the 25th percentile 

 (among the lowest 25 percent 

 of NAWQA stream water studies)

NUTRIENTS IN WATER

Median nutrient concentrations at 

nine streams were generally lower in 

the ACF River Basin than for 219 

NAWQA sites ranked nationally. 

Median phosphorus concentrations 

were only above national medians 

downstream from Atlanta. Nitrate 

concentrations were highest at the 

poultry site (West Fork Little River) 

and the Chattahoochee River downstream from Atlanta. Like most of 

the United States (Mueller and 

others, 1995), all nitrate concentrations in surface water in the ACF 

River Basin were well below the 

drinking-water standard. Ammonia 

concentrations were highest downstream from Atlanta and at the urban 

site (Peachtree Creek). Aquatic-life 

criteria for ammonia were not 

exceeded at these nine sites 

during the study period.

PESTICIDES IN WATER

Pesticide levels at the urban 

(Peachtree Creek) and suburban 

(Sope Creek) sites were in the 

third quartile of 61 NAWQA 

sites ranked nationally, primarily 

because insecticides were 

frequently detected. Median 

monthly concentrations of the 

insecticides diazinon and 

carbaryl exceeded aquatic-life 

criteria at the urban and 

suburban sites, and chlorpyrifos 

exceeded aquatic-life criteria at 

the urban site. Pesticide scores 

at the cropland sites (Lime and 

Aycocks Creeks) were in the 

lowest quartile of NAWQA 

sites, although pesticide use is 

widespread in these areas.

ORGANOCHLORINE PESTICIDES AND PCBs IN 

BED SEDIMENT AND BIOLOGICAL TISSUE

The scores for organochlorine pesticides and PCBs (sediment 

and tissue data combined) at 71 percent of ACF River Basin 

sites were higher than the median score of 202 NAWQA sites. 

Higher scores in the ACF River Basin were primarily at urban, 

cropland, and mixed land-use sites. DDT* or its degradation 

products (DDD, DDE) were detected in 41 percent of tissue 

samples and 52 percent of bed-sediment samples; however, 

concentrations measured in 1992–94 generally were lower than 

those reported in historical data (1965–91). The termiticides 

chlordane* and dieldrin* were primarily detected at sites associated with urban areas. The fire-ant-control insecticide mirex* 

was detected at four agricultural sites in the Coastal Plain. 

Organochlorine pesticides and PCBs* were not detected in 

poultry, forested, and six of seven suburban sites sampled. 

West Point Lake bed sediment had the only exceedances of 

aquatic-life criteria for organochlorine insecticides (total 

chlordane) and PCBs within the ACF River Basin. 

*Used extensively in the Southeastern United States prior to legal 

uses being banned: DDT, 1973; chlordane, 1974 (agriculture), 1988 

(termiticide); dieldrin, 1974 (agriculture), 1987 (termiticide); mirex, 

1976; and PCBs, 1979.

downstream 

Snake

Creek

Chattahoochee River

Lime Creek

Peachtree Creek

Sope Creek Chattahoochee 

 from Atlanta

Apalachicola River

 near Mouth

Aycocks Creek

West Fork

Little River

River upstream

from Atlanta

Albany

Seven major water-quality characteristics were evaluated for stream sites in each NAWQA Study Unit. Summary scores for 

each characteristic were computed for all sites that had adequate data. Scores for each site in the ACF River Basin were 

compared with scores for all sites sampled in the 20 NAWQA Study Units during 1992–95. 

Results are summarized by percentiles; higher percentile values generally indicate poorer 

quality compared with other NAWQA sites. Water-quality conditions at each site also are 

compared to established criteria for protection of aquatic life. Applicable criteria are limited 

to nutrients and pesticides in water, and semivolatile organic compounds, organochlorine 

pesticides and PCBs in sediment. (Methods used to compute rankings and evaluate aquaticlife criteria are described by Gilliom and others, in press.)

WATER-QUALITY CONDITIONS IN A NATIONAL CONTEXT

Comparison of Stream-Water Quality in the Apalachicola–Chattahoochee–Flint River Basin

with Nationwide NAWQA Findings

26 Water Quality in the Apalachicola–Chattahoochee–Flint River Basin, Georgia, Alabama, and Florida, 1992–95

PIEDMONT

COASTAL PLAIN
FISH COMMUNITY 

DEGRADATION

Increasing percentages of 

diseased, pollution-tolerant, 

omnivorous, and non-native fish 

are generally associated with 

degraded fish communities. The 

status of fish communities at five 

out of six sites in the ACF River 

Basin were ranked better than the 

median for 172 NAWQA sites. 

The fish community at the urban 

site (Peachtree Creek) was 

among the most degraded of 

sites across the Nation. Fish 

communities were not evaluated 

at large river sites within the 

ACF River Basin. 

STREAM HABITAT DEGRADATION 

The capacity of a stream to support biological 

communities is influenced by physical habitat 

characteristics including the stability of streambanks, the presence of riparian buffers, and 

modifications such as channelization. In 

comparison to 181 NAWQA sites across the 

Nation, two agricultural sites (Aycocks Creek 

and West Fork Little River) and one forested 

site (Snake Creek) in the ACF River Basin had 

among the best and one urban site (Peachtree 

Creek) had among the worst stream-habitat 

conditions. Two sites were not among the best 

in the Nation because an agricultural site (Lime 

Creek) was channelized and the suburban site 

(Sope Creek) had eroding streambanks. Stream 

habitat was not evaluated at large river sites 

within the ACF River Basin.

CONCLUSIONS

Compared with other NAWQA Study Units, in the Apalachicola-Chattahoochee-Flint (ACF) River Basin: 

• Urban tributaries and the Chattahoochee River downstream from Atlanta were among the most degraded 

sites evaluated by NAWQA during 1992–95. Suburban and agricultural (cropland and poultry) tributaries 

and the Chattahoochee River upstream from Atlanta showed varying degrees of degradation that were 

comparable to many sites evaluated in the Nation. A forested tributary and the Apalachicola River were 

among the least-degraded sites evaluated in the Nation.

• Aquatic-life criteria for bed sediment were exceeded downstream from Atlanta in West Point Lake 

(chlordane and PCBs). 

• Aquatic-life criteria for surface water were exceeded by median monthly concentrations of insecticides in 

the urban site, Peachtree Creek (three insecticides), and the suburban site, Sope Creek (two insecticides).

U.S. Geological Survey Circular 1164 27

TRACE ELEMENTS IN BED SEDIMENT 

Trace-element concentrations of zinc, 

cadmium, lead, copper, and mercury 

in bed sediment were highest downstream from urban areas in the ACF 

River Basin. Concentrations of 

arsenic, nickel, and chromium were 

elevated at some agricultural sites in 

the Coastal Plain. The trace-element 

scores for 41 of 48 sites (85 percent) 

in the ACF River Basin were above 

the median for 198 NAWQA sites. 

Although trace elements occur 

naturally in rocks and sediments, 

measured concentrations in bed 

sediments at many of these sites 

were enriched relative to background conditions.

SEMIVOLATILE ORGANIC 

COMPOUNDS IN BED SEDIMENT 

Semivolatile organic compound 

(SVOC) concentrations in the ACF 

River Basin were highest in tributary 

streams in areas of urban land use 

and in main-stem rivers downstream 

from Metropolitan Atlanta and 

Albany. SVOC concentrations were 

relatively low at poultry, suburban, 

forested, and cropland sites. The 

distribution of SVOC standardized 

scores in the ACF River Basin are 

similar to 198 NAWQA sites ranked 

across the Nation. No exceedances 

of aquatic-life criteria for SVOCs 

were measured within the ACF 

River Basin.

WATER-QUALITY CONDITIONS IN A NATIONAL CONTEXT

Comparison of Stream-Water Quality in the Apalachicola–Chattahoochee–Flint River Basin

with Nationwide NAWQA Findings
Five major water-quality characteristics were evaluated for ground-water studies in each NAWQA Study Unit. Ground-water 

resources were divided into two categories: (1) drinking-water aquifers, and (2) shallow ground water underlying agricultural 

or urban areas. Summary scores were computed for each characteristic for all aquifers and shallow ground-water areas that 

had adequate data. Scores for each aquifer and shallow ground-water area in the ACF River Basin were compared with 

scores for all aquifers and shallow ground-water areas sampled in the 20 NAWQA Study 

Units during 1992–95. Results are summarized by percentiles; higher percentile values 

may indicate poorer quality compared with other NAWQA ground-water studies. Waterquality conditions for each drinking-water aquifer also are compared to established 

drinking-water standards and criteria for protection of human health. (Methods used to 

compute rankings and evaluate standards and criteria are described by Gilliom and 

others, in press.)

NITRATE

Nitrate generally is present in shallow 

aquifers in the ACF River Basin. 

Median nitrate concentrations in the 

ACF River Basin were typical of 

those in other NAWQA ground-water 

study areas. Drinking-water standards 

for nitrate were exceeded in water 

samples from less than 10 percent of 

wells near poultry production and 

cropland and the recharge area to the 

Upper Floridan aquifer. No exceedances occurred in ground-water 

samples from wells and springs in 

Metropolitan Atlanta or in springs 

from the Upper Floridan aquifer.

PESTICIDES

For five ground-water study components 

in the ACF River Basin, one or more 

pesticides were detected at 57 to 81 

percent of sites sampled, placing these 

components in the highest two quartiles 

compared to other NAWQA groundwater study areas. Highly sensitive 

analytical methods have shown that 

low concentrations of some widely 

used pesticides are present in shallow 

ground water underlying urban and 

suburban areas, cropland, and the 

Upper Floridan aquifer. However, 

pesticide concentrations in ground 

water rarely exceeded drinking-water 

standards or guidelines. The banned 

insecticide, dieldrin, exceeded the 

current drinking-water guideline in 

water samples from 5 of 37 locations 

in suburban and urban land use in 

Metropolitan Atlanta. The source of 

this persistent compound probably is 

residual quantities of dieldrin and aldrin 

that were applied prior to 1987 for 

termite control of homes and 

commercial buildings.

EXPLANATION

Drinking-water aquifer

Upper Floridan aquifer

Shallow ground-water areas

Cropland—Darker color represents area

 with a higher density of wells sampled

Urban and suburban

Ranking of ground-water quality relative to all NAWQA 

 ground-water studies—Darker colored circles generally 

 indicate poorer quality. Bold outline of circle indicates one 

 or more standards or criteria were exceeded. 

 "S" indicates spring data

Greater than the 75th percentile (among the highest 

 25 percent of NAWQA ground-water studies)

Between the median and the 75th percentile

Between the 25th percentile and the median

Less than the 25th percentile (among the lowest 

 25 percent of NAWQA ground-water studies)

WATER-QUALITY CONDITIONS IN A NATIONAL CONTEXT

Comparison of Ground-Water Quality in the Apalachicola–Chattahoochee–Flint River Basin

with Nationwide NAWQA Findings

28 Water Quality in the Apalachicola–Chattahoochee–Flint River Basin, Georgia, Alabama, and Florida, 1992–95

S

S

S

S

PIEDMONT

COASTAL PLAIN
S

S

S

S

S

S

WATER-QUALITY CONDITIONS IN A NATIONAL CONTEXT

Comparison of Ground-Water Quality in the Apalachicola–Chattahoochee–Flint River Basin

with Nationwide NAWQA Findings

VOLATILE ORGANIC COMPOUND (VOCs)

In Metropolitan Atlanta, VOCs were detected in 

ground-water samples from slightly more than 

50 percent of the sites sampled, placing 

this study area in the highest quartile for 

springs and wells compared to other 

NAWQA ground-water study areas. 

Twenty-six VOCs commonly associated 

with fuel products, industrial chemicals, 

solvents, and degreasers were detected. 

Chloroform, the most commonly detected 

VOC, is a by-product of disinfecting 

drinking water with chlorine and may be 

present in ground-water recharge from 

septic systems and leaking water and sewer 

lines. Concentrations of tetrachloroethene 

(used extensively in the dry cleaning 

industry) and benzene and napthalene 

(components of gasoline) exceeded 

drinking-water standards in ground-water 

samples from 3 of 37 sites sampled. 

In the Coastal Plain, VOCs were detected 

in ground-water samples from approximately 15 percent of wells and springs in 

the Upper Floridan aquifer and in only 1 of 

37 wells in shallow ground-water areas near 

cropland, placing these study components in 

the third and first quartiles, respectively. 

VOCs detected include compounds present 

in gasoline, compounds used as degreasers 

or solvents, and the banned soil fumigant 

1,2-dichloropropane. 

DISSOLVED SOLIDS

Low dissolved-solids concentrations placed all the ACF 

ground-water study areas in 

the lowest quartile compared 

to other NAWQA study areas. 

Dissolved-solids concentrations in ground water are 

generally related to climatic 

conditions and the composition of rocks and soils more 

than land use. Dissolvedsolids concentrations generally are low in the ACF River 

Basin because there is 

plentiful rainfall and most 

aquifer materials are only 

slightly soluble in water.

RADON

Radon is a short-lived radioactive 

gas that is common in ground water. 

It is introduced into ground water by 

the radioactive decay of uranium 

present in aquifer materials and 

soils. Therefore, the occurrence of 

radon is controlled to a great extent 

by bedrock geology—not land use. 

Metropolitan Atlanta is underlain by 

igneous and metamorphic rocks that 

generally contain higher concentrations of uranium than most other 

rock types in the Study Unit and the 

Nation. Median radon concentrations 

in shallow ground water in Metropolitan Atlanta were in the highest 

quartile for springs and the third 

quartile for wells compared to other 

NAWQA ground-water study areas. 

Median radon concentrations in the 

studies within sediments of the 

Coastal Plain Physiographic Province were in the lowest quartile.

U.S. Geological Survey Circular 1164 29

CONCLUSIONS

Compared with other NAWQA Study Units, in the 

Apalachicola–Chattahoochee–Flint River Basin:

• Median nitrate concentrations in the ground-water 

study areas varied from the lowest to the third 

highest quartile of the NAWQA study areas 

across the Nation; however, nitrate concentrations 

only rarely exceeded the drinking-water standard 

in samples from wells (located near cropland and 

in the Upper Floridan aquifer) and did not exceed 

the standard in samples from springs.

• Pesticides and VOCs were detected more 

frequently in ground-water samples from Metropolitan Atlanta and the Upper Floridan aquifer 

than in most NAWQA study areas across the 

Nation. Although traces of these compounds 

are widely distributed in ground water from 

these study areas, the only exceedances of 

drinking-water standards occurred in samples 

from three springs and five wells located in 

Metropolitan Atlanta. These exceedances in 

shallow ground water in Metropolitan Atlanta 

indicate a potential water-quality concern for 

developing future public drinking-water supplies 

in the underlying fractured-rock aquifer.
SUMMARY OF COMPOUND DETECTIONS AND CONCENTRATIONS 

The following tables summarize data collected for NAWQA studies from 1992-1995 by showing results for the ApalachicolaChattahoochee-Flint River Basin Study Unit compared to the NAWQA national range for each compound detected. In order to represent the wide concentration ranges observed among Study Units, logarithmic scales are used to emphasize the general magnitude of 

concentrations-such as 10, 100, or 1,000-rather than the precise number. The complete dataset used to construct these tables is available upon request. 

Concentrations of herbicides, insecticides, volatile organic compounds, nutrients, and radon detected in ground and surface waters of 

the Apalachicola-Chattahoochee-Flint River Basin Study Unit 

[mg/L, milligrams per liter; μg/L, micrograms per liter; pCi/L, picocuries per liter; %, percent; <, less than; -, not measured] 

EXPLANATION , Freshwater-chronic criterion for the protection of aquatic life a 

Drinking water standard or guideline a 

Range of surface-water detections in all 20 Study Units 

Range of ground-water detections in all 20 Study Units 

Detection in the Apalachicola-Chattahoochee-Flint River Basin Study Unit 

Herbicide Rate Concentration, in μg/L Herbicide Rate Concentration, in μg/L 

of of 

detec- detection b tionb 

I 

30 Water Quality In the Apalachicola-Chattahoochee-Flint River Basin, Georgia, Alabama, and Florida, 1992-95 
SUMMARY OF COMPOUND DETECTIONS AND CONCENTRATIONS 

Herbicide Rate Concentration, in μg/L Volatile organic Rate Concentration, in μg/L 

of compound of 

detec- detection b tion b 

Triclopyr 

Trifluralin 

Insecticide Rate Concentration, in μg/L 

of 

detec- 0.001 0.01 0.1 1 10 100 1,000 

tionb 

I I 

erbufos 

<1% 

U.S. Geological Survey Circular 1164 31 
SUMMARY OF COMPOUND DETECTIONS AND CONCENTRATIONS 

Volatile Organic Rate Concentration, in μg/L Nutrient Rate Concentration, in mg/L 

detec- detection b tion b 

-Propylbenzene Dissolved ammonia 94% 

57% 

compound of of 

Dissolved ammonia 

plus organic nitrogen 48% as nitrogen 11% 

sec-Butylbenzene 

Dissolved phospho- 49% 

rus as phosphorus 40% 

Dissolved nitrite plus 98% 

Volatile organic Rate Concentration, in μg/L nitrate 91% 

compound of 

Other Rate Concentration, in pCi/L detecof 

ethyl tert-butyl detecTetrachloroethene don 222 

(Radon) 

Herbicides, insecticides, and volatile organic compounds not detected in ground and surface waters of the Apalachicola-ChattahoocheeFlint River Basin Study Unit. 

Herbicides Molinate Methyl parathion 1,2,3-Trichlorobenzene Bromochloromethane 

2.4.5-T Neburon Oxamyl 1,2,3-Trichloropropane Bromethane 

Pebulate Phorate 1,2,4-Trichlorobenzene Chloroethane 

Acetochlor Picloram Propargite 1,2-Dibromo-3-chloropro- Chloroethene 

Propham cis-Permethrin pane Dibromomethane Acifluorfen 

Thiobencarb 1,2-Dibromoethane Dichloromethane Bromoxynil 

Triallate Volatile organic 1,2-Dichlorobezene Ethenylbenzene Chloramben compounds 

Clopyralid 1,3-Dichlorobenzene Hexachlorobutadiene 

Insecticides Dacthal mono-acid 

(Dacthal metabolite) 3-H y drox ycarbofuran 1-Chloro-2-methylbenzene tert-Butylbenzene 

Dichlorprop 

Dinoseb 

EPTC 

Fenuron 

2,4,5-TP 

1 , 1 , 1,2-Tetrachloroethane 1,3-Dichloropropane cis- 1.3-Dichloropropene 

1,1,2,2-Tetrachloroethane 

1-Chloro-4-methylbenzene trans- 1,2-Dichloroethene oroethane 

1,1,2-Trichloroethane 

1,1-Dichloropropene 

(Carbofuran metabolite) 1,1,2-Trichloro-1,2,2-trifluAldicarb 2,2-Dichloropropane trans- 1.3-Dichloropropene 

Methiocarb Bromobenzene 

Methomyl 

a Selected water-quality standards and guidelines and sediment-quality guidelines (Gilliom and others, in press). 

b Rates of detection are based on the number of analyses and detections in the Study Unit, not on national data. Rates of detection for herbicides and 

insecticides were computed by only counting detections equal to or greater than 0.01 μg/L in order to facilitate equal comparisons among compounds, which had widely varying detection limits. For herbicides and insecticides, a detection rate of "<1%” means that all detections are less than 

0.01 μg/L, or the detection rate rounds to less than I percent. For other compound groups, all detections were counted and minimum detection limits 

for most compounds were similar to the lower end of the national ranges shown. Method detection limits for all compounds in these tables are summarized in Gilliom and others (in press). 

c Detections of these compounds are reliable, but concentrations are determined with greater uncertainty than for the other Compounds and are reported 

as estimated values (Zaugg and others, 1995). 

d The guideline for methyl tert-butyl ether is between 20 and 40 μg/L; if the tentative cancer classification C is accepted, the lifetime health advisory will 

be 20 μg/L (Gilliom and others, in press). 

32 Water Quality In the Apalachicola-Chattahoochee-Flint River Basin, Georgia, Alabama, and Florida, 1992-95 
SUMMARY OF COMPOUND DETECTIONS AND CONCENTRATIONS 

Concentrations of semivolatile organic compounds, organochlorine compounds, and trace elements detected in clam and fish tissue and 

bed sediment of the Apalachicola-Chattahoochee-Flint River Basin Study Unit 

[μg/g, micrograms per gram; μg/kg, micrograms per kilogram; %, percent; <, less than; -, not measured] 

EXPLANATION Guideline for the protection of aquatic life a 

Range of detections in fish and clam tissue in all 20 Study Units 

Range of detections in bed sediment in all 20 Study Units 

Detection in bed sediment in the Apalachicola-Chattahoochee-Flint River Basin Study Unit 

Detection in clam or fish tissue in the Apalachicola-Chattahoochee-Flint River Basin Study Unit 

Semivolatile Rate of Concentration, in μg/kg Semivolatile Rate of Concentration, in μg/kg 

organic compound detec- organic compound detection b tion b 

U.S. Geological Survey Circular 1164 33 
SUMMARY OF COMPOUND DETECTIONS AND CONCENTRATIONS 

Semivolatile Trace element Rate Concentration, in μg/g 

organic compound detec- of 

Rate of Concentration, in μg/kg 

tion b detection b 

Semivolatile organic compounds and organochlorine compounds not 

detected in clam and fish tissue and bed sediment of the 

Apalachicola-Chattahoochee-Flint River Basin Study Unit. 

Semivolatile organic Benzo [c] cinnoline Isodrin 

compounds C8-Alkylphenol Pentachloroanisole 

pentachlorophenol 1,2,4-Trichlorobenzene Nitrobenzene 

metabolite) 1,2-Dichlorobenzene Pentachloronitrobenzene 

1,3-Dichlorobenzene Quinoline Toxaphene 

Organochlorine Rate Concentration, 1,4-Dichlorobenzene Organochlorine alpha-HCH in μg/kg 

of 

compound 2,4-Dinimotoluene detection b 2-Chloronaphthalene Chloroneb 

compounds cis-Permethrin 

delta-HCH 

gamma-HCH 2-Chlorophenol DCPA 

4-Bromophenyl-phenylethr Endin o,p '-Methoxychlor 

4-Chloro-3-methylphenol Heptachlor p,p '-Methoxychlor 

4-Chlorophenyl-phenylether Hexachlorobenzene trans-Permethrin 

3,s-Dimethylphenol Endosulfan I 

a Selected water-quality standards and guidelines and sediment-quality 

guidelines (Gilliom and others, in press). 

b Rates of detection are based on the number of analyses and detections in 

the Study Unit, not on national data. Rates of detection for herbicides 

and insecticides were computed by only counting detections qual to or 

greater than 0.01 μg/L in order to facilitate equal comparisons among 

compounds, which had widely varying detection limits. For herbicides 

and insecticides, a detection rate of "<1%” means that all detections are 

less than 0.01 μg/L, or the detection rate rounds to less than 1percent. 

For other compound groups, all detections were counted and minimum 

detection limits for most compounds were similar to the lower end of the 

national ranges shown. Method detection limits for all compounds in 

these tables are summarized in Gilliom and others (in press). 

34 Water Quality In the Apalachicola-Chattahoochee-Flint River Basin, Georgia, Alabama, and Florida, 1992-95 
U.S. Geological Survey Circular 1164 35

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watersheds, White County, Georgia, 

1992-93: U.S. Geological Survey 

Open-File Report 94-540, 31 p.

Stamey, T.C., 1995, Floods in central and 

southwestern Georgia in July 1994, in 

Hatcher, K.J. ed., proceedings, 1995 

Georgia Water Resources Conference: 

Athens, Ga., Vinson Institute of 

Government, The University of 

Georgia, p. 313-316.

——1996, Summary of data-collection 

activities and effects of flooding from 

Tropical Storm Alberto in parts of 

Georgia, Alabama, and Florida, July 

1994: U.S. Geological Survey OpenFile Report 96-228, 23 p

Stell, S.M., Hopkins, E.H., Buell, G.R., and 

Hippe, D.J., 1995, Use and occurrence 

of pesticides in the ApalachicolaChattahoochee-Flint River basin, 
36 Water Quality in the Apalachicola-Chattahoochee-Flint River Basin, Georgia, Alabama, and Florida, 1992-95

REFERENCES AND GLOSSARY

Georgia, Alabama, and Florida, 1960-

91: U.S. Geological Survey Open-File 

Report 95-739, 65 p.

U.S. Bureau of the Census, 1991, Census of 

population and housing, 1990: Public 

Law 94-171 (Alabama, Florida, and 

Georgia): Washington, D.C., U.S. 

Department of Commerce, Bureau of 

the Census, digital data series, 

CD-ROM.

U.S. Environmental Protection Agency, 

1986, Quality criteria for water 1986: 

Washington, D.C., U.S. Environmental 

Protection Agency Report 440/5-86-

001, Office of Water [variously paged].

——1990, Maximum contaminant levels 

(subpart B of 141, National primary 

drinking water regulations) (revised 

July 1, 1990): U.S. Code of Federal 

Regulations, Title 40, Parts 100-149, p. 

559-563.

U.S. Geological Survey, 1977–80, Land use 

and land cover digital data, 1972–78, 

Apalachicola, Atlanta, Athens, Dothan, 

Greenville, Macon, Phenix City, 

Rome, Tallahassee, and Waycross 

quadrangles: U.S. Geological Survey, 

scale 1:250,000.

Van Metre, P.C., Callender, Edward, and 

Fuller, C.C., 1997, Historical trends in 

organochlorine compounds in river 

basins identified using sediment cores 

from reservoirs: Environmental 

Science and Technology, v. 31, no. 8, 

p. 2339-2344.

Wangsness, D.J., 1997, The National 

Water-Quality Assessment 

Program—Example of study unit 

design for the ApalachicolaChattahoochee-Flint River basin in 

Georgia, Alabama, and Florida, 1991-

97: U.S. Geological Survey Open-File 

Report 97-48, 29 p.

Zaugg, S.D., Sandstrom, M.W., Smith, 

S.G., and Fehlberg, K.M., 1995, 

Methods of analysis by the U.S. 

Geological Survey National Water 

Quality Laboratory—Determination of 

pesticides in water by C-18 solid-phase 

extraction and capillary-column gas 

chromatography/mass spectrometry 

with selected-ion monitoring: U.S. 

Geological Survey Open-File Report 

95-181, 49 p.

GLOSSARY

Ammonia—A compound of nitrogen and 

hydrogen (NH3) that is a common byproduct of animal waste. Ammonia readily 

converts to nitrate in soils 

and streams.

Aquatic guidelines—Specific levels of 

water quality which, if reached, may 

adversely affect aquatic life. These are 

nonenforceable guidelines issued by a 

governmental agency or other institution.

Aquifer—A water-bearing layer of soil, 

sand, gravel, or rock that will yield usable 

quantities of water to a well.

Atmospheric deposition—The transfer of 

substances from the air to the surface of 

the Earth, either in wet form (rain, fog, 

snow, dew, frost, hail) or in dry form 

(gases, aerosols, particles).

Background concentration—A 

concentration of a substance in a particular 

environment that is indicative of minimal 

influence by human (anthropogenic) 

sources.

Base flow—Sustained, low flow in a 

stream; ground-water discharge is the 

source of base flow in most places.

Basic Fixed Sites—Sites on streams at 

which streamflow is measured and samples 

are collected for temperature, salinity, 

suspended sediment, major ions and 

metals, nutrients, and organic carbon to 

assess the broad-scale spatial and temporal 

character and transport of inorganic 

constituents of streamwater in relation to 

hydrologic conditions and environmental 

settings. 

Basin—See Watershed.

Bed sediment—The material that 

temporarily is stationary in the bottom of a 

stream or other water course.

Benthic invertebrates—Insects, mollusks, 

crustaceans, worms, and other organisms 

without a backbone that live in, on, or near 

the bottom of lakes, streams, or oceans.

Carbonate—Rock or sediment composed 

of more than 50 percent carbonate 

minerals such as limestone or dolomite.

Clastic—Rock or sediment composed 

principally of broken fragments that are 

derived from preexisting rocks which have 

been transported from their place of origin, 

as in sandstone.

Combined sewer overflow—A discharge 

of untreated sewage and stormwater to a 

stream when the capacity of a combined 

storm/sanitary sewer system is exceeded 

by storm runoff.

Community—In ecology, the species that 

interact in a common area.

Concentration—The amount or mass of a 

substance present in a given volume or 

mass of sample. Usually expressed as 

microgram per liter (water sample) or 

micrograms per kilogram (sediment or 

tissue sample).

Denitrification—A process by which 

oxidized forms of nitrogen such as nitrate 

(NO3

-

) are reduced to form nitrites, nitrogen oxides, ammonia, or free nitrogen: 

commonly brought about by the action of 

denitrifying bacteria and usually resulting 

in the escape of nitrogen to the air.

Detect—To determine the presence of 

a compound.

Detection limit—The concentration below 

which a particular analytical method 

cannot determine, with a high degree of 

certainty, a concentration.

Dieldrin—An organochlorine insecticide 

no longer registered for use in the United 

States. Also a degradation product of the 

insecticide aldrin.

Discharge—Rate of fluid flow passing a 

given point at a given moment in time, 

expressed as volume per unit of time.

Drinking-water standard or 

guideline—A threshold concentration in a 

public drinking-water supply, designed to 

protect human health. As defined here, 

standards are U.S. Environmental 

Protection Agency regulations that specify 

the maximum contamination levels for 

public water systems required to protect 

the public welfare; guidelines have no 

regulatory status and are issued in an 

advisory capacity.

Effluent—Outflow from a particular 

source, such as a stream that flows from a 

lake or liquid waste that flows from a 

factory or sewage-treatment plant.

EPT richness index—An index based on 

the sum of the number of taxa in three 

insect orders, Ephemeroptera (mayflies), 

Plecoptera (stoneflies), and Trichoptera 

(caddisflies), that are composed primarily 

of species considered to be relatively 

intolerant to environmental alterations.
U.S. Geological Survey Circular 1164 37

GLOSSARY

Eutrophication—The process by which 

water becomes enriched with plant 

nutrients, most commonly phosphorus 

and nitrogen.

Fertilizer—Any of a large number of 

natural or synthetic materials, including 

manure and nitrogen, phosphorus, and 

potassium compounds, spread on or 

worked into soil to increase its fertility.

Flood plain—The relatively level area of 

land bordering a stream channel and 

inundated during moderate to 

severe floods.

Fumigant—A substance or mixture of 

substances that produces gas, vapor, fume, 

or smoke intended to destroy insects, 

bacteria, or rodents.

Ground water—In general, any water that 

exists beneath the land surface, but more 

commonly applied to water in fully 

saturated soils and geologic formations.

Habitat—The part of the physical 

environment where plants and 

animals live.

Headwaters—The source and upper part 

of a stream.

Herbicide—A chemical or other agent 

applied for the purpose of killing 

undesirable plants. See also Pesticide.

Index of Biotic Integrity (IBI)—An 

aggregated number, or index, based on 

several attributes or metrics of a fish 

community that provides an assessment of 

biological conditions.

Insecticide—A substance or mixture of 

substances intended to destroy or 

repel insects.

Intensive Fixed Sites—Basic Fixed Sites 

with increased sampling frequency during 

selected seasonal periods and analysis of 

dissolved pesticides for 1 year. Most 

NAWQA Study Units have one to two 

integrator Intensive Fixed Sites and one to 

four indicator Intensive Fixed Sites.

Intolerant organisms—Organisms that 

are not adaptable to human alterations to 

the environment and thus decline in 

numbers where human alterations occur.

Intensive Fixed Sites—Basic Fixed Sites 

with increased sampling frequency during 

selected seasonal periods and analysis of 

dissolved pesticides for 1 year. Most 

NAWQA Study Units have one to two 

integrator Intensive Fixed Sites and one to 

four indicator Intensive Fixed Sites.

Karst—A type of topography that results 

from dissolution and collapse of 

carbonate rocks such as limestone and 

dolomite, and characterized by closed 

depressions or sinkholes, caves, and 

underground drainage.

Load—General term that refers to a 

material or constituent in solution, in 

suspension, or in transport; usually 

expressed in terms of mass or volume.

Macroinvertebrate—An animal that is 

large enough to be seen without 

magnification and has no backbone or 

spinal column.

Main stem—The principal course of a 

river or a stream.

Median—The middle or central value in a 

distribution of data ranked in order of 

magnitude. The median is also known as 

the 50th percentile.

Micrograms per liter (μg/L)—A unit 

expressing the concentration of 

constituents in solution as weight 

(micrograms) of solute per unit volume 

(liter) of water; equivalent to one part per 

billion in most streamwater and ground 

water. One thousand micrograms per liter 

equals 1 mg/L.

Milligrams per liter (mg/L)—A unit 

expressing the concentration of chemical 

constituents in solution as weight 

(milligrams) of solute per unit volume 

(liter) of water; equivalent to one part per 

million in most streamwater and ground 

water. One thousand micrograms per liter 

equals 1 mg/L.

Nitrate—An ion consisting of nitrogen 

and oxygen (NO3

-

). Nitrate is a plant 

nutrient and is very mobile in soils.

Nonpoint source—A pollution source that 

cannot be defined as originating from 

discrete points such as pipe discharge. 

Areas of fertilizer and pesticide 

applications, atmospheric deposition, 

manure, and natural inputs from plants and 

trees are types of nonpoint 

source pollution.

Nonselective herbicide—Kills or 

significantly retards growth of most higher 

plant species.

Nutrient—Element or compound essential 

for animal and plant growth. Common 

nutrients in fertilizer include nitrogen, 

phosphorus, and potassium.

Occurrence and distribution 

assessment—Characterization of the 

broad-scale spatial and temporal 

distributions of water-quality conditions in 

relation to major contaminant sources and 

background conditions for surface water 

and ground water.

Organic compound—A compound 

containing at least one carbon-carbon bond 

(C—C) or one carbon-hydrogen bond 

(C—H).

Organic detritus—Any loose organic 

material in streams—such as leaves, bark, 

or twigs—removed and transported by 

mechanical means, such as disintegration 

or abrasion.

Perched ground water—Water in an 

isolated, saturated zone overlying a layer 

of material with low hydraulic 

conductivity and separated from the main 

body of ground water by unsaturated 

sediment or rock. Perched ground water 

has a perched water table.

Pesticide—A chemical applied to crops, 

rights of way, lawns, or residences to 

control weeds, insects, fungi, nematodes, 

rodents or other "pests".

pH—The logarithm of the reciprocal of 

the hydrogen ion concentration (activity) 

of a solution; a measure of the acidity (pH 

less than 7) or alkalinity (pH greater than 

7) of a solution; a pH of 7 is neutral.

Phenols—A class of organic compounds 

containing C6H5OH and its derivatives. 

Used to make resins, weed killers, and as a 

solvent, disinfectant, and chemical 

intermediate. Some phenols occur 

naturally in the environment.

Phosphorus—A nutrient essential for 

growth that can play a key role in 

stimulating aquatic growth in lakes 

and streams.

Phthalates—A class of organic 

compounds containing phthalic acid esters 

[C6H4(COOR)2] and derivatives. Used as 

plasticizer in plastics. Also used in many 

other products (such as detergents, 

cosmetics) and industrial processes (such 

as defoaming agents during paper and 

paperboard manufacture, and dielectrics 

in capacitors).
38 Water Quality in the Apalachicola-Chattahoochee-Flint River Basin, Georgia, Alabama, and Florida, 1992-95

GLOSSARY

Point source—A source at a discrete 

location such as a discharge pipe, drainage 

ditch, tunnel, well, concentrated livestock 

operation, or floating craft.

Polychlorinated biphenyls (PCBs)—A 

mixture of chlorinated derivatives of 

biphenyl, marketed under the trade name 

Aroclor with a number designating the 

chlorine content (such as Aroclor 1260). 

PCBs were used in transformers and 

capacitors for insulating purposes and in 

gas pipeline systems as a lubricant. Further 

sale for new use was banned by law in 

1979.

Polycyclic aromatic hydrocarbon 

(PAH)—A class of organic compounds 

with a fused-ring aromatic structure. PAHs 

result from incomplete combustion of 

organic carbon (including wood), 

municipal solid waste, and fossil fuels, as 

well as from natural or anthropogenic 

introduction of uncombusted coal and oil. 

PAHs include benzo(a)pyrene, 

fluoranthene, and pyrene.

Preemergence herbicide—Herbicide 

applied to bare ground after planting the 

crop but prior to the crop sprouting above 

ground to kill or significantly retard the 

growth of weed seedlings.

Postemergence herbicide—Herbicide 

applied to foliage after the crop has 

sprouted to kill or significantly retard the 

growth of weeds.

Recurrence interval—The average time 

interval between occurrences of a 

hydrologic event, such as a flood, of a 

given or greater magnitude.

Runoff—Excess rainwater or snowmelt 

that is transported to streams by overland 

flow, tile drains, or ground water.

Sanitary sewer overflow—A discharge of 

untreated sewage resulting from clogged 

sewer pipes or inoperative pumping 

stations. Untreated sewage overflows from 

manholes and leaky pipes into nearby 

streams rather than backing up into homes 

or businesses.

Selective herbicide—Kills or significantly 

retards growth of an unwanted plant 

species without significantly damaging 

desired 

plant species.

Semivolatile organic compound 

(SVOC)—Operationally defined as a 

group of synthetic organic compounds that 

are solvent-extractable and can be 

determined by gas chromatography/mass 

spectrometry. SVOCs include phenols, 

phthalates, and Polycyclic aromatic 

hydrocarbons (PAHs).

Surface water—An open body of water, 

such as a lake, river, or stream.

Suspended sediment—Particles of rock, 

sand, soil, and organic detritus carried in 

suspension in a water column, in 

contrast to sediment that moves on or near 

a streambed.

Synoptic sites—Sites sampled during a 

short-term investigation of specific waterquality conditions during selected seasonal 

or hydrologic conditions to provide 

improved spatial resolution for critical 

water-quality conditions. 

Tile drain—A buried perforated pipe 

designed to remove excess water

from soils.

Total concentration—Refers to the 

concentration of a constituent regardless of 

its form (dissolved or bound) in 

a sample.

Trace element—An element found in only 

minor amounts (concentrations less than 

1.0 milligram per liter) in water or 

sediment; includes arsenic, cadmium, 

chromium, copper, lead, mercury, nickel, 

and zinc.

Upland—Elevated land above low areas 

along a stream or between hills; elevated 

region from which rivers gather drainage.

Volatile organic compounds (VOCs)— 

Organic chemicals that have a high vapor 

pressure relative to their water solubility. 

VOCs include components of gasoline, 

fuel oils, and lubricants, as well as organic 

solvents, fumigants, some inert ingredients 

in pesticides, and some by-products of 

chlorine disinfection.

Watershed—The portion of the surface of 

the Earth that contributes water to a stream 

through overland run-off, including 

tributaries and impoundments.

Wetlands—Ecosystems whose soil is 

saturated for long periods seasonally or 

continuously, including marshes, swamps, 

and ephemeral ponds.

Yield—The mass of material or 

constituent transported by a river in a 

specified period of time divided by the 

drainage area of the river basin.
Frick and others • Water Quality in the Apalachicola-Chattahoochee-Flint River Basin

USGS Circular 1164 • 1998

National Water-Quality Assessment (NAWQA) Program

Apalachicola-Chattahoochee-Flint River Basin

NAWQA

Columbus

Albany

Dothan

Lake Blackshear

Lake Seminole

Walter F.

 George Reservoir

West Point Lake

Lake Sidney Lanier

Chattahoochee R.

Flint

Rive r

Apa al ch icola R .

GEORGIA

ALABAMA

FLORIDA

Atlanta