NATIONAL WATER-QUALITY ASSESSMENT PROGRAM Basin

MAJOR WATER-QUALITY WHAT IS THE NATIONAL WATER-QUALITY ASSESSMENT PROGRAM? ISSUES IN THE MOBILE RIVER During the past 25 years, industry and government made large financial investments BASIN intended to improve water quality across the Nation; however, many water-quality issues Assessing water quality in the remain. To address the need for consistent and scientifically sound information for man- Mobile River Basin is important for the aging the Nation’s water resources, the U.S. Geological Survey began a full-scale protection and efficient use of water and National Water-Quality Assessment (NAWQA) Program in 1991. This program is other aquatic resources. The Mobile unique compared to other national water-quality assessment studies in that it integrates River Basin NAWQA study is intended the monitoring of the quality of surface and ground waters with the study of aquatic eco- to increase the scientific understanding systems. The goals of the NAWQA Program are to (1) describe current water-quality of surface- and ground-water quality conditions for a large part of the Nation’s freshwater streams and aquifers (water-bearing within the basin and the factors that sediments and rocks), (2) describe how water quality is changing over time, and influence water quality. (3) improve our understanding of the primary natural and human factors affecting water quality.

The blue shiner is listed as a threatened species in . (Photograph courtesy of Malcolm Pierson) Assessing the quality of water in every location in the Nation would not be practi- cal; therefore, NAWQA Program studies are conducted within a set of areas called study This NAWQA study also provides units. These study units are composed of 59 important river and aquifer systems that rep- information needed by water-resource resent the diverse geography, water resources, and land and water uses of the Nation. The managers to implement effective water- Mobile River Basin is one such study unit, designed to address issues relevant to the quality management actions and evalu- Mobile River Basin while supplementing water-quality information collected in other ate long-term changes in water quality. study units across the Nation. The U.S. Geological Survey began the Mobile River Basin During the planning process, the follow- NAWQA study in 1997. ing water-quality issues that currently face water-resource managers in the to urbanization, agriculture, and ¥ Effects of acid-mine drainage Mobile River Basin were prioritized: silviculture. on surface-water quality. ¥ Pesticides and toxics compounds ¥ Bacterial contamination of sur- ¥ Nutrient enrichment of ground in surface and ground water from face and ground waters. and surface waters from human agricultural, industrial, and urban and animal wastes and runoff from activities. ¥ The quality of surface- and urban and agricultural areas. ¥ Degradation of instream and ground-water discharges to ¥ Sedimentation and increased con- riparian habitats and the subse- and how they relate centrations of sediment in streams quent impacts upon native species to the health of the estuarine and reservoirs from erosion related and water quality. environment and its fisheries.

U.S. Department of the Interior USGS Fact Sheet FSÐ100Ð98 U.S. Geological Survey October 1998 STUDY UNIT DESCRIPTION and Tombigbee Rivers is gen- erally regulated by upstream The Mobile River Basin encompasses reservoirs, flood-control and 2 44,000 square miles (mi ) in Georgia, Tennes- navigational locks and dams, see, Alabama, and and comprises and hydroelectric plants. In the Alabama and Tombigbee Rivers that meet 1985, the Tennessee-Tombigbee to form the Mobile River. The Mobile River Waterway was opened. It flows south into Mobile Bay, which discharges joined the Tennessee and Tom- into the . Approximately bigbee Rivers to provide a new 71 percent of the study unit lies within Ala- trade route connecting Mobile bama, 14 percent in Mississippi, 13 percent in and the Gulf Coast with the Georgia, and 2 percent in Tennessee. An esti- mid-section of the Nation. Res- mated 4.9 million people lived in the study unit ervoirs on the Alabama and in 1990. The largest population centers in the Tombigbee Rivers and their study unit (populations greater than 100,000) tributaries are also used for © Alabama Air Foto include Birmingham, Mobile, Montgomery, Birmingham is the largest city in the study unit. Continued and Tuscaloosa. drinking water and recreational residential development may stress the aquatic habitats of activities such as fishing, suburban streams. The major land use in the Mobile River swimming, and boating. Basin is forested land, which covers approxi- Landforms in the Mobile River Basin primarily underlain by sand and gravel aqui- mately 69 percent of the study unit. The study unit range from rugged mountains to fer systems which are important sources for remaining land uses include agricultural land coastal lowlands and are included in five phys- drinking water. Water in the Coastal Plain is (18 percent), urban (2 percent), and other uses iographic provinces. The Blue Ridge and Pied- produced from shallow ground water and such as wetlands, streams, lakes, and reservoirs mont, located in the northeast corner of the from deep ground water which is confined (11 percent). Agricultural activities include row study unit, are characterized by igneous and by impermeable layers of chalk and clay crops such as cotton, corn, hay, and soybeans, metamorphic rocks and encompass 16 percent deposits. as well as aquaculture, and poultry and cattle of the basin. To the east, the Valley and Ridge production. Major industries include silvicul- consists of a series of parallel ridges and val- Based on 1995 water-use data, approxi- ture, chemical, pulp and paper, iron and steel, leys, all having a northeast trend. It is under- mately 1,340 million gallons per day coal, textile manufacturing, and hydroelectric- lain by sandstone, shale, limestone, and (Mgal/d) were withdrawn from surface- power. dolomite rocks. The Valley and Ridge includes and ground-water sources for public, com- 16 percent of the basin. The Appalachian Pla- mercial, and domestic supplies and for teaus, which encompasses 12 percent of the industrial and agricultural uses in the Mobile basin, is dominated by relatively flat plateaus Riber Basin. Surface water is the principal and is underlain largely by nearly flat-lying source, accounting for about 76 percent of sandstones, limestones, and shales. The the water withdrawn (1,020 Mgal/d); about remaining 56 percent of the study unit is 42 percent is used for public-water supplies included in the Coastal Plain, which is prima- (430 Mgal/d) and 44 percent is used for rily underlain by unconsolidated or poorly industrial purposes (453 Mgal/d). Approxi- consolidated sands, gravels, clays, and lime- mately 76 percent of the ground-water with- stones. Elevations in the study unit range from drawals were used for public and domestic near sea level along the Mobile River in the drinking-water supplies (198 and 49 Mgal/d, respectively). More than 80 percent of the U.S. Geological Survey photo Coastal Plain to greater than 3,000 feet above public-water supplies were from surface- Silviculture is the largest industry in Alabama. sea level in the Blue Ridge Mountains of Geor- gia. Average annual precipitation ranges from water sources in the non-Coastal Plain Prov- The Mobile River basin is the sixth larg- 50 to greater than 60 inches, with higher inces, whereas nearly 60 percent of the est basin in the Nation and the fourth largest in amounts in the mountainous regions; average public-water supplies were from ground- terms of streamflow. The mean annual stream- annual runoff ranges from 18 to 30 inches. water sources in the Coastal Plain. flow of the Mobile River is about 64,000 cubic Average annual air temperatures vary from feet per second (ft3/s). The about 60 degrees Fahrenheit (o F) in the north Basin, which drains 22,800 mi2, annually con- to about 70o F in the south. tributes 33,600 ft3/s of streamflow to the Mobile River, whereas the Tombigbee River The Blue Ridge and Piedmont are under- Basin (20,200 mi2) annually contributes lain by a fractured, crystalline-rock aquifer 30,200 ft3/s. Major tributaries to the Alabama characterized by little or no pore spaces and River are the Coosa (10,161 mi2), Tallapoosa openings and the overlying unconsolidated, (4,675 mi2), and Cahaba (1,825 mi2) River weathered rock remnants and soil. The Valley Basins, which have a combined mean annual and Ridge and Appalachian Plateaus are streamflow of 24,000 ft3/s, or 71 percent of the underlain by fractured-rock systems in the mean annual streamflow from the Alabama well-consolidated sandstones and intercon- River Basin. The principal tributary to the nected fractured rock systems in the cavernous Tombigbee River is the limestone and dolomite rocks which become Basin (6,276 mi2), which has a mean annual enlarged as water flows through them. Caves streamflow of 9,800 ft3/s and is about 32 per- Fishing is one of the recreational uses and sinkholes in the limestone rocks increase of reservoirs in the Mobile River Basin. cent of the mean annual streamflow from the the susceptibility of ground water to contami- (Photo courtesy of the Alabama Bureau Tombigbee River Basin. Flow in the Alabama nation from surface water. The Coastal Plain is of Tourism and Travel) 85O TN O EXPLANATION 35 AL ELEVATION IN FEET

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SCHEDULE OF STUDY ACTIVITIES

Activity 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010

Plan and review Intensive data collection Reports Low-intensity monitoring

The Mobile River Basin study is one During the planning period, exist- the study unit. Measurements will be of several NAWQA studies that began ing data and results from previous made to determine water chemistry in in Federal fiscal year 1997 (October studies will be reviewed to understand streams and aquifers; the quantity of sus- 1996). Study planning and design, and the primary physical, chemical, and pended sediment and the quality of bot- analysis of existing data will be done biological factors that affect water tom sediments in streams; the variety during the first 2 years, which is consis- quality in the study unit and to iden- and number of fish, benthic inverte- tent with all NAWQA studies. After the tify gaps in the current data. Informa- 2-year planning period, surface- and tion obtained from reviews of previous brates, and algae in streams; and the ground-water and biological data will studies, along with field checks of presence of contaminants in fish tissues. be collected intensively for 3 years dur- existing monitoring stations and candi- Individual streams and aquifers, chemi- ing a high-intensity phase. A low- date sampling sites and field recon- cal constituents, and biological species intensity phase follows for 6 years, dur- naissance data, will be used to design a will be selected for sampling to represent ing which water quality will be moni- sampling program for the study unit. the important water resources and tored at a selected number of sites and water-quality concerns in the study unit areas assessed during the high-intensity During the high-intensity phase, and the Nation. A series of technical and phase. This combination of high- and new chemical, physical, and biological low-intensity-monitoring phases data will be collected from selected nontechnical reports describing results of allows the NAWQA Program to exam- areas on local and regional scales to high- and low-intensity-phase data ine trends in water quality over time. describe the quality of water throughout collection and analysis are planned. ASSESSING WATER QUALITY IN THE river basin or to provide greater spatial cover- MOBILE RIVER BASIN STUDY UNIT age and allow investigators to assess relations of fixed sites to streams throughout the study COMMUNICATION AND The NAWQA Program is designed to unit. Synoptic surface-water sampling involves COORDINATION assess the status of and trends in the quality short-term investigations of specific water- Communication and coordination of the Nation’s ground- and surface-water quality conditions at numerous sites during between the U.S. Geological Survey and resources and to link the status and trends selected hydrologic periods, such as periods of other scientific and land- and water- with an understanding of the natural and low streamflow. management organizations are critical human factors that affect the quality of components of the NAWQA Program. water. Consistent data-collection and assess- Ecology Each study unit maintains a liaison com- ment methods in all NAWQA studies make mittee consisting of representatives from this possible and are critical for providing Ecological studies in conjunction with Federal, State, and local agencies, uni- uniform and comparable information on surface-water sampling activities are conducted versities, the private sector, watershed water quality for the nation. Surface-water, to provide insight into ecological variability organizations, and those who have ecological, and ground-water studies are over time, relations between water quality and water-resource responsibilities and inter- done on local (a few square miles to hun- community structure and stability, and ecologi- ests. Committee activities include the dreds of square miles) and regional (thou- cal differences with respect to various environ- exchange of information about regional sands of square miles) scales to understand mental settings. Aquatic biological communi- and local water-quality issues, identifica- the water-quality conditions and issues ties are surveyed at basic- and intensive-fixed tion of sources of data and information, within a study unit. NAWQA study-unit data sites during the 3-year high-intensity phase. assistance in the design and scope of collected using this multiscale, interdiscipli- These investigations are conducted along delin- study products, and the review of study nary approach will be aggregated to provide eated stream reaches and include aquatic and planning documents and reports. The national-scale water-quality assessments. riparian habitat assessments and annual surveys liaison committee for the Mobile River Partnerships and cooperative studies of fish, algal, and benthic invertebrate commu- Basin study met for the first time in between local, State, and Federal agencies nities. Trace elements and synthetic organic October 1997. can be developed to help meet specific compounds are analyzed in bed sediment and needs. The basic design for the Mobile River fish tissue at selected sites to determine their The overall success of the Mobile Basin study unit described in the following occurrence and distribution and relation to land River Basin NAWQA study will depend sections is similar among NAWQA study use and environmental setting. Ecological syn- on the advice, cooperation, and informa- tion from many Federal, State, regional, units nationwide. optic studies are conducted to evaluate spatial and local agencies, and the public con- variability of biological communities or address Surface Water cerned about the basin’s water resources. issues of special concern within the study unit. Surface-water quality is monitored at The assistance and suggestions of all are two types of sites, basic-fixed sites and welcomed. Ground Water intensive-fixed sites, which are determined by the frequency of the sampling. Most Ground-water studies in the NAWQA NAWQA study units have about eight basic- SUGGESTIONS FOR FURTHER READING fixed and four intensive-fixed sites. Basic- Program are typically composed of three com- ponents: (1) study-unit survey, (2) land-use fixed sites are sampled on a regular basis, Gilliom, R.J., Alley, W.M., and Gurtz, M.E., usually monthly, for 2 years during the studies, and (3) an optional flow-path study. 1995, Design of the National Water- 3-year high-intensity phase. Intensive-fixed The study-unit survey is intended to character- Quality Assessment Program: Occurrence sites are monitored more frequently for at ize water quality in the major aquifers of the and distribution of water-quality least 1 year to characterize short-term varia- study unit without targeting specific land uses. conditions: U.S. Geological Survey tions of water quality. Both types of sites are About 30 wells are randomly selected for sam- Circular 1112, 33 p. used to monitor water-quality constituents, pling in each major aquifer subunit in the study such as basic field properties, major ions, unit. Ground-water samples are analyzed for Leahy, P.P., Rosenshein, J.S., and Knopman, nutrients, and pesticides. Volatile organic major ions, nutrients, and pesticides. Trace ele- D.S., 1990, Implementation plan for the compounds (VOC’s) and trace elements also ments and VOC’s also may be monitored. National Water-Quality Assessment may be monitored at selected sites. Monitor- Program: U.S. Geological Survey Open- ing sites are selected to determine represen- Land-use studies attempt to characterize File Report 90-174, 10 p. tative water-quality conditions in relation to the quality of shallow ground water associated important environmental settings in the with a particular land-use setting. Land-use FOR MORE INFORMATION study unit. studies emphasize recently recharge ground water so that the influences of land-use prac- Information on technical reports and hydrologic data Basic-fixed or intensive-fixed sites are tices and environmental settings can be related to the NAWQA Program can be obtained further classified as either indicator or inte- assessed. About 30 wells are randomly selected from: grator sites. Indicator sites represent rela- within a selected land-use setting for an aqui- tively homogeneous and usually small fer. Results from land-use studies will be com- J. Brian Atkins, Study Chief basins associated with environmental set- pared with results from study-unit surveys to Mobile River NAWQA tings, such as a specific land use that is con- determine the effect of land use on ground- U.S. Geological Survey sidered to be important for understanding water quality. 2350 Fairlane Drive, Suite 120 water-quality in the study unit. Integrator Montgomery, Alabama 36116 sites are established at downstream points in (334) 213Ð2332 Flow-path studies are intended to help large drainage basins that incorporate com- identify and quantify processes controlling Email: [email protected] plex combinations of land-use settings. shallow ground-water movement and quality. Internet: http://wwwrvares.er.usgs.gov/nawqa/ Water quality at integrator sites reflects the These studies, performed in selected study nawqa_home.html effects of multiple land uses and transport in the basin. units, are designed to trace chemical changes By: J. Brian Atkins that occur in water as it enters the ground-water Synoptic surface-water sampling can flow system, travels along a flow path, and Masthead photograph courtesy of the Alabama be used to address a selected issue in one eventually discharges into surface waters. Bureau of Tourism and Travel