U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2014–3044

August 2014

Prepared in cooperation with the Louisiana Department of Transportation and Development 

Water Resources of Caldwell Parish, Louisiana

Introduction

Information concerning the availability, use, and quality 

of water in Caldwell Parish, Louisiana (fig. 1), is critical for 

proper water-supply management. The purpose of this fact 

sheet is to present information that can be used by water 

managers, parish residents, and others for stewardship of this 

vital resource. Information on the availability, past and current 

use, use trends, and water quality from groundwater and 

surface-water sources in the parish is presented. Previously 

published reports (see References Cited section) and data 

stored in the U.S. Geological Survey’s National Water 

Information System (http://waterdata.usgs.gov/nwis) are the 

primary sources of the information presented here. 

In 2010, about 4.39 million gallons per day (Mgal/d) of 

water were withdrawn in Caldwell Parish, including about 

2.67 Mgal/d from surface-water sources and 1.73 Mgal/d from 

groundwater sources1

 (table 1). Withdrawals for various use 

categories are presented in table 2. Water-use data collected at 

5-year intervals from 1960 to 2010 (fig. 2) indicated that water 

withdrawals peaked in 1980. 

1

Tabulation of numbers in text and tables may result in different totals 

because of rounding; nonrounded numbers are used for calculation of totals. 

bia

A

A'

Mississippi 

River 

alluvial

 aquifer

Sparta

aquifer

Cockfield

aquifer

Bayou

Lafourche

Ouachita River

Boeuf River

Beaucoup

Creek

Castor Creek

Bills Creek

Riverton

Fort Necessity

Columbia

Grayson

Clarks

4

165

EXPLANATION

Approximate altitude of base of fresh

 groundwater, in feet below National

 Geodetic Vertical Datum of 1929

 (modified from Smoot, 1988)

 0 to 49

 50 to 499

 500 to 899

Approximate area where no major aquifer

 contains freshwater

Approximate boundary of area showing deepest

 freshwater contained within Mississippi River

 alluvial, Cockfield, and Sparta aquifers 

Line of section (see fig. 3)

Well for which hydrograph is shown

 (see fig. 4)

U.S. Geological Survey surface-water 

 discharge site and number (see table 4)

U.S. Geological Survey surface-water 

 quality site and number (see table 4)

Ca-86A,B

A'A

07367630

07367640

O

C

CALDWELL

PARISH

FRANKLIN

PARISH

RICHLAND

PARISH

OUACHITA PARISH

JACKSON

PARISH

WINN

PARISH

LA SALLE

PARISH

CATAHOULA

PARISH

TEXAS

ARKANSAS MISSISSIPPI

LOUISIANA

CALDWELL

PARISH

07369000

C

Ca-86A,B

07367630

07370500 07367640

07369150

C

C

O

O

Base modified from U.S. Geological Survey digital data

Albers Equal-Area Conic projection

North American Datum of 1983

92°10' 92°00'

32°10'

32°00'

10 KILOMETERS

0

0 2 4 6 8

2 4 6 8 10 MILES

Figure 1. Location of study area, Caldwell Parish, Louisiana. 
Table 1. Water withdrawals, in million gallons per day, by source 

in Caldwell Parish, Louisiana, 2010 (modified from Sargent, 2011).

Aquifer or surfacewater body Groundwater Surface water

Mississippi River

alluvial aquifer

0.61

Cockfield aquifer 1.09

Sparta aquifer 0.02

Miscellaneous 

streams

2.67

Total 1.73 2.67

Table 2. Water withdrawals, in million gallons per day, by use 

category in Caldwell Parish, Louisiana, 2010 (modified from 

Sargent, 2011).

Use category Groundwater Surface 

water Total

Public supply 1.07 0.00 1.07

Rural domestic 0.07 0.00 0.07

Livestock 0.03 0.03 0.05

Rice irrigation 0.57 1.32 1.88

General irrigation 0.00 1.32 1.32

Total 1.73 2.67 4.39

0

2

4

6

8

10

12

14

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

Year

Groundwater

Surface water

EXPLANATION

Annual withdrawals, in million gallons per day

(Sargent, 2011).

Figure 2. Water withdrawals in Caldwell Parish, Louisiana, 1960–2010 

Groundwater Resources

Fresh groundwater (water with a chloride concentration of 250 

milligrams per liter [mg/L] or less) is available throughout Caldwell 

Parish except near the extreme southeastern corner of the parish. 

The base of freshwater is present at depths generally ranging from 

less than 100 to 800 feet (ft) below the National Geodetic Vertical 

Datum of 1929 (NGVD 29) (Smoot, 1988). The primary sources 

of fresh groundwater in Caldwell Parish are the Mississippi River 

alluvial aquifer and the Cockfield aquifer. A minor source of fresh 

groundwater underlying the parish is the Sparta aquifer (fig. 3, table 

1). Recharge to aquifers in the parish is from precipitation, leakage 

from adjacent aquifers, and seasonal input from streams. Discharge 

from the aquifers is by evapotranspiration, natural seasonal flow into 

streams, leakage into adjacent aquifers, and withdrawals from wells. 

State well-registration records listed 208 active water wells 

in Caldwell Parish in 2010, including 90 domestic, 78 irrigation, 

33 public supply, and 7 industrial (Louisiana Department of Natural 

Resources, 2011). In 2010, categories of use for groundwater 

withdrawals included public supply, rural domestic, livestock, and 

rice irrigation (table 2). 

Mississippi River Alluvial Aquifer

In Caldwell Parish, the Mississippi River alluvial aquifer is 

present from roughly the Ouachita River to the eastern boundary 

of the parish and ranges in thickness from less than 25 to 75 ft 

(Ackerman, 1996). The base of the aquifer in the parish is an 

uneven surface that ranges in altitude from about 0 to 40 ft or more 

below NGVD 29 (Whitfield, 1975). Freshwater is generally present 

throughout the alluvial aquifer in Caldwell Parish (fig. 1); however, 

small lenses of saltwater (water with a chloride concentration 

greater than 250 mg/L) are locally present within the aquifer 

(Whitfield, 1975). 

Recharge to the Mississippi River alluvial aquifer is primarily 

from precipitation and, to a lesser degree, by leakage from underlying 

sediments such as the Cockfield aquifer. Natural discharge occurs by 

seepage into streams (Whitfield, 1975). The direction of groundwater 

flow in the alluvial aquifer in Caldwell Parish is generally toward 

Bayou Lafourche and the Boeuf River (fig. 1). In 1990, water levels 

in the aquifer were generally 50 ft or more above NGVD 29 along 

the Ouachita River in the northern part of the parish and less than 

40 ft above NGVD 29 along the Boeuf River in the southeastern 

corner of the parish (Seanor and Smoot, 1995). 

State well-registration records listed 109 active wells screened 

in the Mississippi River alluvial aquifer in Caldwell Parish in 2010, 

including 2 public supply, 68 irrigation, 38 domestic, and 1 industrial 

well. Depths of these wells ranged from 27 to 130 ft below land 

surface, with a median depth of 90 ft. Reported yields from wells 

screened in the Mississippi River alluvial aquifer in Caldwell Parish 

have ranged from 5 to 3,000 gallons per minute (gal/min) (Louisiana 

Department of Natural Resources, 2011). In 2010, groundwater 

withdrawals from the Mississippi River alluvial aquifer in Caldwell 

Parish totaled about 0.61 Mgal/d (table 1), and uses included about 

0.03 Mgal/d for rural domestic, 0.02 Mgal/d for livestock, and 

0.57 Mgal/d for rice irrigation. 

A statistical summary of selected water-quality characteristics of 

freshwater samples from 10 wells screened in the Mississippi River 

alluvial aquifer in Caldwell Parish is listed in table 3. Freshwater 

from the aquifer generally is very hard.2

 The data are limited but 

indicate that concentrations of iron and manganese greatly exceed 

the U.S. Environmental Protection Agency’s Secondary Maximum 

Contaminant Levels3 (SMCLs) for drinking water. 

2

Hardness ranges, expressed as milligrams per liter of calcium carbonate, are as follows: 

0–60, soft; 61–120, moderately hard; 121–180, hard; greater than 180, very hard (Hem, 1985). 3

The SMCLs are nonenforceable Federal guidelines regarding cosmetic effects (such as 

tooth or skin discoloration) or aesthetic effects (such as taste, odor, or color) of drinking 

water. At high concentrations or values, health implications as well as aesthetic degradation 

might exist. SMCLs were established as guidelines for the States by the U.S. Environmental 

Protection Agency (1992). 
500

NGVD 29

-500

-1,000

-1,500

-2,000

-2,500

0 5

5 10 KILOMETERS

10 MILES

0

NORTH

A

SOUTH

A'

FEET

500

NGVD 29

-500

-1,000

-1,500

-2,000

-2,500

FEET

Approximate land surface

VERTICAL DATUM IS NATIONAL GEODETIC VERTICAL DATUM OF 1929 (NGVD 29)

VERTICAL SCALE GREATLY EXAGGERATED

Vicksburg-Jackson 

confining unit

Cook Mountain confining unit

Sparta aquifer

Deeper aquifers in the parish contain saltwater

Cockfield aquifer

Cane River confining unit

?

?

Base of freshwater

Bill’s Creek

 Grayson

EXPLANATION

Mostly clay

? Queried where uncertain

Base of freshwater (modified 

from Smoot, 1988)

Cockfield Aquifer

The Cockfield aquifer is present throughout Caldwell Parish 

except in the northeastern corner of the parish where it is thin or 

absent (Ryals, 1984). The aquifer outcrops and receives recharge 

from precipitation west of the Ouachita River, except in the 

stream valleys of Castor Creek and its tributaries and in the southcentral part of the parish where the aquifer is overlain by clay 

of the Vicksburg-Jackson confining unit (Snead and McCulloh, 

1984) (fig. 3). The Cook Mountain confining unit underlies the 

Cockfield aquifer. 

In Caldwell Parish, the Cockfield aquifer dips to the 

southeast, and the base of the aquifer ranges in altitude from about 

0 ft below NGVD 29 in the northwestern corner of the parish to 

nearly 1,000 ft below NGVD 29 in the southeastern corner. Aquifer 

thickness ranges from less than 200 ft along the northwestern 

parish line to 600–800 ft in the southeastern corner of the parish 

(Ryals, 1984). The Cockfield aquifer generally contains freshwater 

in Caldwell Parish; however, in the southeastern corner and along 

the eastern margin of the parish, the aquifer contains saltwater 

(Brantly and Seanor, 1996; Ryals, 1984). The altitude of the base of 

freshwater within the Cockfield aquifer in central and southwestern 

Caldwell Parish is shown in figure 1. 

The direction of groundwater flow in the Cockfield aquifer 

in Caldwell Parish is generally eastward toward the Ouachita 

River. In 1993, water levels were generally more than 140 ft 

above NGVD 29 in the northwestern corner of the parish and 

about 60 ft above NGVD 29 along the Ouachita River Valley 

(Brantly and Seanor, 1996). The water level in well Ca-86A (fig. 

1), which is screened in the Cockfield aquifer, fluctuates from 2 to 

6 ft or more annually but has remained at about the same altitude 

since 2002 (fig. 4). 

Figure 3. Generalized northto-south hydrogeologic section 

through Caldwell Parish, 

Louisiana, showing aquifer 

and confining unit intervals 

(individual sand and clay 

layers not shown) (modified 

from Huner, 1939 and Smoot, 

1988). Trace of section shown 

on figure 1.

State well-registration records listed 75 active wells screened

in the Cockfield aquifer in Caldwell Parish in 2010, including 

39 domestic, 26 public supply, 6 industrial, and 4 irrigation wells. 

Depths of these wells ranged from 50 to 630 ft below land surface, 

with a median depth of 335 ft. Reported yields from wells screened 

in the Cockfield aquifer in Caldwell Parish have ranged from 10 to 

400 gal/min (Louisiana Department of Natural Resources, 2011). 

Water withdrawals from the Cockfield aquifer in Caldwell Parish 

totaled about 1.09 Mgal/d (table 1) in 2010, and uses included about 

1.05 Mgal/d for public supply, 0.03 Mgal/d for rural domestic, and 

0.01 Mgal/d for livestock. 

A statistical summary of selected water-quality characteristics 

of freshwater from 54 wells screened in the Cockfield aquifer in 

Caldwell Parish is presented in table 3. Freshwater from the aquifer 

generally is soft and generally does not exceed the SMCLs for 

color, pH, and concentrations of chloride and dissolved solids. Iron 

concentrations often greatly exceed the SMCL of 300 micrograms 

per liter (μg/L), and manganese concentrations generally exceed the 

SMCL of 50 μg/L. 

Sparta Aquifer 

The Sparta aquifer is present throughout Caldwell Parish but 

contains freshwater only in the northwestern quadrant of the parish. 

The aquifer lies between massive clay beds of the underlying Cane 

River confining unit and the overlying Cook Mountain confining 

unit (fig. 3) (Rollo, 1960). 

In Caldwell Parish, the Sparta aquifer dips to the southeast and 

the base of the aquifer ranges in altitude from about 800 ft below 

NGVD 29 in the extreme northwestern corner of the parish to 

nearly 2,000 ft below NGVD 29 in the extreme southeastern corner. 
Table 3. Summary of selected water-quality characteristics of freshwater in the Mississippi River alluvial, Cockfield, and Sparta aquifers in 

Caldwell Parish, Louisiana (U.S. Geological Survey, 2012b).

[Values are in milligrams per liter, except as noted. °C, degrees Celsius; PCU, platinum cobalt units; μS/cm, microsiemens per centimeter; SU, standard units; 

CaCO3, calcium carbonate; μg/L, micrograms per liter; —, insufficient data; SMCL, Secondary Maximum Contaminant Level established by the U.S. Environmental 

Protection Agency (2012); NA, not applicable; <, less than]

Temperature (°C)Color,

(PCU) 

Specific

conductance,

field (μS/cm

at 25 °C)

pH,

field

(SU)

Hardness

(as 

CaCO3

)

Chloride,

filtered

(as Cl)

Iron,

filtered

(μg/L as Fe)

Manganese,

filtered

(μg/L as Mn)

Dissolved

solids,

filtered

Mississippi River alluvial aquifer, 1970–2011 (10 wells) 

Median 20.1 5 537 7.2 210 20 8,200 980 156

10th percentile 19.5 — 346 — 150 11 4,400 540 —

90th percentile 20.5 — 698 — 300 78 12,000 3,000 —

Number of samples 9 1 7 2 8 10 8 7 1

Percentage of samples 

that do not exceed 

SMCLs

NA 100 NA 100 NA 100 0 0 100

Cockfield aquifer, 1939–89 (54 wells) 

Median 20.6 5 414 7.5 40 20 1,200 80 272

10th percentile 19.5 5 263 6.5 2 9.3 70 20 190

90th percentile 21.8 50 715 8.5 110 38 6,000 250 412

Number of samples 14 41 38 40 54 54 34 23 37

Percentage of samples 

that do not exceed 

SMCLs

NA 78 NA 88 NA 100 29 35 92

Sparta aquifer, 1947–2012 (13 wells) 

Median 23.0 120 1,540 8.5 8 80 80 <1 757

10th percentile 22.1 55 1,070 8.2 2 18 20 <1 651

90th percentile 24.1 200 1,970 8.8 27 140 1,000 16 1,120

Number of samples 5 8 10 8 12 13 8 5 6

Percentage of samples 

that do not exceed 

SMCLs

NA 0 NA 62 NA 100 75 100 0

SMCLs

NA 15 NA 6.5–8.5 NA 250 300 50 500

The thickness of the aquifer ranges from 600 to 800 ft throughout 

the parish except in the southeastern corner, where the thickness 

is from 800 to 1,000 ft (Ryals, 1984). The altitude of the base of 

freshwater within the Sparta aquifer in northwestern Caldwell 

Parish is shown in figure 1. 

In 2007, water levels in the Sparta aquifer in Caldwell Parish 

ranged from about 80 ft above NGVD 29 in the southwestern 

corner of the parish to about 20 ft below NGVD 29 in the 

northwestern corner (Schrader, 2008). Regional groundwater 

withdrawals have greatly affected the direction of groundwater 

flow in the Sparta aquifer. In Caldwell Parish, the direction of 

groundwater flow in the Sparta aquifer is northward toward a 

pumping center in Ouachita Parish (Schrader, 2008). The water 

level in well Ca-86B (fig. 1), which is screened in the Sparta 

aquifer in Caldwell Parish, declined about 8 ft between 2002 and 

2013 (fig. 4). 

State well-registration records listed 14 active wells screened in 

the Sparta aquifer in Caldwell Parish in 2010, including 9 domestic 

and 5 public supply. Well depths ranged from 400 to 845 ft below land 

surface, with a median depth of 525 ft. Reported yields from wells 

screened in the Sparta aquifer in Caldwell Parish have ranged from 

2 to 140 gal/min (Louisiana Department of Natural Resources, 2011). 

In 2010, groundwater withdrawals from the Sparta aquifer in Caldwell 

Parish totaled about 0.02 Mgal/d (table 1), primarily for public supply. 

A statistical summary of selected water-quality characteristics of 

freshwater from 13 wells screened in the Sparta aquifer in Caldwell 

Parish is presented in table 3. Freshwater from the aquifer generally 

is soft and generally does not exceed the SMCLs for concentrations 

of iron and manganese. Color and dissolved solids concentrations 

exceeded the SMCLs in sampled wells. The median value for pH is 

at the upper SMCL limit of 8.5 standard units, indicating that water in 

the Sparta aquifer tends to be alkaline. 
Year

2000 2002 2004 2006 2008 2010 2012 2014

Water level, altitude in feet (ft) 

70

80

90

100

110

120

Well: Ca-86B

Altitude of land surface: 160 ft above NGVD 29

Well depth: 545 ft below land surface 

Well: Ca-86A

Altitude of land surface: 160 ft above NGVD 29

Well depth: 288 ft below land surface 

Figure 4. Water levels in well Ca-86A screened in the Cockfield aquifer and well Ca-86B screened in the Sparta aquifer in Caldwell Parish, 

Louisiana (see fig. 1 for well locations; U.S. Geological Survey, 2012a). Altitude of land surface and water level is measured in feet (ft) above 

the National Geodetic Vertical Datum of 1929 (NGVD 29). 

Surface-Water Resources 

In 2010, about 2.67 Mgal/d of surface water were 

withdrawn in Caldwell Parish, and uses included about 

0.03 Mgal/d for livestock, 1.32 Mgal/d for rice irrigation, and 

1.32 Mgal/d for general irrigation (tables 1 and 2). Notable 

surface-water bodies in the parish are the Ouachita River, Bayou 

Lafourche, Boeuf River, Castor Creek, and Beaucoup Creek 

(fig. 1). The average daily discharge for the Ouachita River at 

Columbia L&D (Lock and Dam) near Riverton (site number 

07367630; fig. 1) during 1982–87 was about 21,326 cubic feet 

per second (ft3

/s). During 1940–71, the average daily discharge 

for Castor Creek near Grayson (site number 07370500) was 

243 ft3

/s. During 1938–2012, the average daily discharge for 

Bayou Lafourche near Crew Lake (site number 07369000), 

located roughly 16 mi north-northeast of Caldwell Parish, was 

1,818 ft3

/s (U.S. Geological Survey, 2013). 

Water samples analyzed during 1974–93 (table 4) indicated 

that water in the Ouachita River at Columbia (site number 

07367640) is soft and that samples generally do not exceed 

the SMCLs for pH and concentrations of chloride and sulfate. 

Dissolved oxygen is generally greater than 5 mg/L, which is 

considered the minimum value for a diversified population 

of fresh, warmwater biota, including sport fish (Louisiana 

Department of Environmental Quality, 2008). Water samples 

analyzed during 1975–91 from the Boeuf River near Fort 

Necessity (site number 07369150; table 4) indicated that the 

median value for hardness fell within the moderately hard range 

and that samples generally do not exceed the SMCLs for pH and 

concentrations of chloride, sulfate, and iron. Dissolved oxygen 

concentrations are generally greater than 5 mg/L. 

Ackerman, D.J., 1996, Hydrology of the Mississippi River valley alluvial 

aquifer, south-central United States: U.S. Geological Survey Professional 

Paper 1416-D, 56 p.

Brantly, J.A., and Seanor, R.C., 1996, Louisiana ground-water map no. 9—

Potentiometric surface, 1993, and water-level changes, 1968–93, of the 

Cockfield aquifer in northern Louisiana: U.S. Geological Survey WaterResources Investigations Report 95-4241, 2 sheets, accessed January 24, 

2012, at http://pubs.er.usgs.gov/publication/wri954241.

Hem, J.D., 1985, Study and interpretation of the chemical characteristics of 

natural water (3d ed.): U.S. Geological Survey Water-Supply Paper 2254, 

264 p., accessed February 20, 2013, at http://pubs.er.usgs.gov/publication/

wsp2254.

Huner, John, Jr., 1939, Geology of Caldwell and Winn Parishes: Department 

of Conservation, Louisiana Geological Survey, Geological Bulletin no. 15, 

356 p.

Louisiana Department of Environmental Quality, 2008, Environmental 

Regulatory Code, Title 33, Part IX, Subpart 1: Baton Rouge, Louisiana 

Department of Environmental Quality, accessed December 27, 2012, at 

http:www.deq.louisiana.gov/portal/tabid/1674/Default.aspx.

Louisiana Department of Natural Resources, 2011, Strategic Online Natural 

Resources Information System (SONRIS): Louisiana Department of Natural 

Resources database, accessed February 14, 2011, at http://sonris.com/.

Rollo, J.R., 1960, Ground water in Louisiana: Department of Conservation, 

Louisiana Geological Survey, and Louisiana Department of Public Works, 

Water Resources Bulletin no. 1, 84 p.

Ryals, G.N., 1984, Regional geohydrology of the northern Louisiana saltdome basin, part II, geohydrologic maps of the Tertiary aquifers and related 

confining layers: U.S. Geological Survey Water-Resources Investigations 

Report 83-4135, 6 p., accessed December 27, 2012, at http://pubs.er.usgs.

gov/publication/wri834135.

Sargent, B.P., 2011, Water use in Louisiana, 2010: Louisiana Department of 

Transportation and Development Water Resources Special Report no. 17, 

135 p. 

References Cited 
Table 4. Summary of selected water-quality characteristics for the Ouachita and Boeuf Rivers in Caldwell Parish, Louisiana (U.S. 

Geological Survey, 2012b).

[Values are in milligrams per liter, except as noted. μS/cm, microsiemens per centimeter; °C, degrees Celsius; SU, standard units; CaCO3, calcium carbonate; μg/L, 

micrograms per liter; SMCL, Secondary Maximum Contaminant Level established by the U.S. Environmental Protection Agency (2012); NA, not applicable]

Specific

conductance, 

field (μS/cm

at 25 °C)

Oxygen, 

dissolved

pH,

field

(SU)

Hardness (as 

CaCO3

)

Calcium, 

filtered 

(as Ca)

Magnesium, 

filtered

(as Mg)

Sodium, 

filtered 

(as Na)

Chloride, 

filtered 

(as Cl)

Sulfate, 

filtered 

(as SO4

)

Iron,

filtered 

(μg/L

as Fe)

Ouachita River at Columbia, 1974–931

Median 168 7.2 6.7 31 8.4 2.1 19 29 13 280

10th percentile 88 4.7 6.1 19 5.0 1.3 8.3 13 6.8 110

90th percentile 324 10.3 7.2 48 14 3.1 40 61 23 550

Number of samples 154 148 155 154 154 154 153 153 151 73

Percentage of samples 

that do not exceed 

SMCLs

NA NA 66 NA NA NA NA 100 100 62

Boeuf River near Fort Necessity, 1975–912

Median 395 7.7 7.2 100 26 8.3 34 53 16 100

10th percentile 87 4.9 6.4 25 6.6 2.0 6.4 7.0 6.0 10

90th percentile 1,040 10.6 7.8 200 50 18 130 210 32 280

Number of samples 95 93 96 96 96 96 96 96 96 40

Percentage of samples 

that do not exceed 

SMCLs

NA NA 88 NA NA NA NA 96 100 90

SMCLs

NA NA 6.5–8.5 NA NA NA NA 250 250 300

1

Site number 07367640. 

2

Site number 07369150.

Schrader, T.P., 2008, Potentiometric surface in the Sparta-Memphis aquifer of 

the Mississippi Embayment, spring 2007: U.S. Geological Survey Scientific 

Investigations Map 3014, 1 sheet, accessed December 4, 2012, at http://pubs.

er.usgs.gov/publication/sim3014.

Seanor, R.C., and Smoot, C.W., 1995, Louisiana ground-water map no. 6—

Potentiometric surface, 1990, and water-level changes, 1974–90, of the 

Mississippi River alluvial aquifer in northeastern Louisiana: U.S. Geological 

Survey Water-Resources Investigations Report 95-4146, 2 sheets, accessed 

December 5, 2012, at http://pubs.er.usgs.gov/publication/wri954146.

Smoot, C.W., 1988, Louisiana hydrologic atlas map no. 3—Altitude of the base of 

freshwater in Louisiana: U.S. Geological Survey Water-Resources Investigations 

Report 86-4314, 1 sheet, accessed December 27, 2012, at http://pubs.er.usgs.gov/

publication/wri864314.

Snead, J.I., and McCulloh, R.P., comps., 1984, Geologic map of Louisiana: Baton 

Rouge, Louisiana Geological Survey, scale 1:500,000. 

U.S. Environmental Protection Agency, 1992, Secondary Drinking Water 

Regulations—Guidance for nuisance chemicals: U.S. Environmental Protection 

Agency publication EPA 810/K-92-001, 4 p., accessed December 27, 2012, at 

http://water.epa.gov/drink/contaminants/secondarystandards.cfm.

U.S. Environmental Protection Agency, 2012, 2012 Edition of the drinking 

water standards and health advisories: U.S. Environmental Protection 

Agency publication EPA 822-S-12-001, Office of Water, 12 p., accessed 

December 27, 2012, at http://water.epa.gov/action/advisories/drinking/upload/

dwstandards2012.pdf.

U.S. Geological Survey, 2012a, Groundwater levels for Louisiana: National Water 

Information System Web Interface, accessed December 18, 2012, at http://nwis.

waterdata.usgs.gov/la/nwis/gwlevels.

U.S. Geological Survey, 2012b, Water quality samples for Louisiana: National 

Water Information System Web Interface, accessed December 19, 2012, at http://

nwis.waterdata.usgs.gov/la/nwis/qwdata.

U.S. Geological Survey, 2013, USGS surface-water daily statistics for the 

Nation: National Water Information System Web Interface, accessed 

November 19, 2013, at http://waterdata.usgs.gov/nwis.

Whitfield, M.S., Jr., 1975, Geohydrology and water quality of the Mississippi 

River alluvial aquifer, northeastern Louisiana: Louisiana Department of 

Public Works Water Resources Technical Report no. 10, 29 p. 

This fact sheet was published by the U.S. Geological 

Survey, in cooperation with the Louisiana Department 

of Transportation and Development (DOTD). Thanks 

are given to Zahir “Bo” Bolourchi, Director, Water 

Resources Programs, DOTD, who contributed to the 

content of the fact sheet.

By Lawrence B. Prakken and Vincent E. White

For additional information, contact: 

Director, USGS Louisiana Water Science Center

3535 S. Sherwood Forest Blvd., Suite 120

Baton Rouge, LA 70816

E-mail: dc_la@usgs.gov

Fax: (225) 298–5490

Telephone: (225) 298–5481

Home Page: http://la.water.usgs.gov

ISSN 2327-6916 (print)

ISSN 2327-6932 (online)

http://dx.doi.org/110.3133/fs20143044