U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2016-3069

January 2017

Prepared in cooperation with the Louisiana Department of Transportation and Development 

Water Resources of East Feliciana Parish, Louisiana

Introduction

Information concerning the availability, use, and quality 

of water in East Feliciana Parish, Louisiana (fig. 1), is critical 

for proper water-resource 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 is presented on the availability, 

past and current use, use trends, and water quality from 

groundwater and surface-water sources in the parish. 

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 3.76 million gallons per day (Mgal/d) 

of water were withdrawn in East Feliciana Parish, including 

about 3.51 Mgal/d from groundwater sources and 0.25 Mgal/d 

from surface-water sources1

 (table 1). Withdrawals for public 

supply accounted for about 80 percent (3.00 Mgal/d) of total 

water use (table 2). Other categories of use included industrial, 

rural domestic, livestock, and general irrigation. Water-use data 

collected at 5-year intervals from 1960 to 2010 (fig. 2) indicated 

that water withdrawals peaked in 1960 at about 4.29 Mgal/d. 

The general increase in groundwater withdrawals since 1975 is 

largely attributable to increasing withdrawals for public supply, 

from 0.20 Mgal/d in 1960 to 3.00 Mgal/d in 2010. 

1

Water-withdrawal data are based on estimated or reported site-specific data 

and aggregated data, which are distributed to sources. For a full description 

of water-use estimate methodology, see "Data Collection" in Sargent (2011). 

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

rounding; nonrounded numbers are used for calculation of totals. 

63

67

19

68

422

10

10

61

Bayou

Sara-Thompson

subbasin

Amite subbasin

Lower MississippiBaton Rouge

subbasin

Bayou

Sara-Thompson

subbasin

Amite subbasin

Lower MississippiBaton Rouge

subbasin

ST HELENA

PARISH

EAST

BATON ROUGE

PARISH

WEST

FELICIANA

PARISH

WEST

BATON ROUGE

PARISH

POINTE COUPEE

PARISH

ST HELENA

PARISH

EAST

BATON ROUGE

PARISH

WEST

FELICIANA

PARISH

WEST

BATON ROUGE

PARISH

POINTE COUPEE

PARISH

EAST

FELICIANA

PARISH

90°50'

31°00'

91°00'

91°10'

30°50'

91°20'

30°40'

Darlington

Clinton

Norwood

Olive Branch

A'

A

EF-61

EF-185

07377000

07373420

07377500

LOUISIANA

MISSISSIPPI

Thompson Creek

East Fork Amite River

Mississippi River

Comite Creek Pretty

 Creek

Comite River

Redwood Creek

Beaver Creek

Sandy

Creek

West Fork Amite River

Horton Bayou

Amite River Amite River

0 10 MILES

0 10 KILOMETERS

EXPLANATION

Approximate altitude of base of fresh

 groundwater, in feet below National 

 Geodetic Vertical Datum of 1929 

 (modified from Smoot, 1988)—Deepest 

 freshwater contained within the Jasper

 equivalent aquifer system

 1,000 to 1,499

 1,500 to 1,999

 2,000 and deeper

Line of hydrogeologic section (see fig. 3)

River subbasin boundary

Well for which hydrograph is shown

 (see fig. 4)

U.S. Geological Survey surface-water

 discharge site and number

U.S. Geological Survey surface-water

 quality site and number (see table 4) 

EF-61

A'A

07375800

07377000

07373420

GULF OF MEXICO

EAST FELICIANA

PARISH

TEXAS

ARKANSAS MISSISSIPPI

LOUISIANA

Lake Maurepas

07373291

Base modified from U.S. Geological Survey digital data

Albers Equal-Area Conic projection

North American Datum of 1983

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

in East Feliciana Parish, Louisiana, 2010 (Sargent, 2011).

Aquifer, aquifer system, or

surface-water body Groundwater Surfacewater

Chicot equivalent aquifer system 0.34

Evangeline equivalent aquifer system 0.29

Jasper equivalent aquifer system 2.12

Catahoula aquifer 0.76

Miscellaneous streams 0.25

Total 3.51 0.25

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

category in East Feliciana Parish, Louisiana, 2010 (modified from 

Sargent, 2011).

Use category Groundwater Surface water Total

Public supply 3.00 0.00 3.00

Industrial 0.03 0.00 0.03

Rural domestic 0.27 0.00 0.27

Livestock 0.02 0.19 0.22

General irrigation 0.18 0.06 0.24

Total 3.51 0.25 3.76

0

1

2

3

4

5

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

Year

Annual withdrawal, in million gallons per day

Groundwater

Surface water

EXPLANATION

Figure 2. Water withdrawals in East Feliciana Parish, Louisiana, 

1960–2010 (Sargent, 2011).

Groundwater Resources

The primary sources of fresh groundwater (water with a 

chloride concentration of 250 milligrams per liter [mg/L] or 

less) in East Feliciana Parish are, from shallowest to deepest, 

the Chicot, Evangeline, and Jasper equivalent aquifer systems 

and the Catahoula aquifer (fig. 3). Deeper aquifers underlying 

the parish contain saltwater (water with a chloride concentration 

greater than 250 mg/L). The base of freshwater is shallowest 

on the western parish border at less than 1,500 feet (ft) below 

the National Geodetic Vertical Datum of 1929 (NGVD 

29) and deepest in the eastern half of East Feliciana Parish 

(fig. 1), with depths up to 2,300 ft below NGVD 29 in the 

northeastern corner (Griffith, 2003). The primary source 

of recharge to the aquifers containing freshwater in East 

Feliciana Parish comes from infiltration of precipitation 

falling in the parish and northward to about 100 miles into 

Mississippi. Flow from streams may also contribute recharge 

to a lesser degree. Discharge from aquifers in the parish is 

by leakage into adjacent aquifers, flow into streams, and 

withdrawals from wells. Aquifers in the parish generally dip 

south to southwest (Griffith, 2003). Individual aquifers, which 

are primarily composed of sand, are generally separated by 

layers of clay but merge in areas where the clay layers are 

missing (Griffith, 2003). 

The Chicot Equivalent Aquifer System

The sole aquifer composing the Chicot equivalent aquifer 

system in East Feliciana Parish is the Upland terrace aquifer, 

which is a broad, somewhat discontinuous near-surface 

aquifer that is present throughout the parish. The Upland 

terrace aquifer crops out along ridges and alongside stream 

valleys within the parish and generally dips south to southwest 

at a rate of 10–30 ft per mile, eventually merging with the 

“400-foot” and “600-foot” sands of the Baton Rouge area 

near the southern parish line. Upland terrace sediments range 

in grain size from clay through silt and sand to gravel and 

can reach a thickness of 300 ft or greater. Aquifer materials 

are composed mainly of the medium- to coarse-grained sand 

portion of the sediments (Morgan, 1963). Regionally, the 

proximity of the Upland terrace aquifer to the surface allows 

the aquifer to receive infiltration of rainfall and transmit this 

water to recharge the deeper aquifers underlying the parish. 

The base of the Upland terrace aquifer is greater than 200 ft 

above NGVD 29 in the northern part of the parish and reaches 

from 100 to 200 ft below NGVD 29 at the southern end of the 

parish (Griffith, 2003).

In 2009, water levels in wells screened in the Upland 

terrace aquifer in East Feliciana Parish ranged from a 

low of about NGVD 29 near the Mississippi River in the 

extreme southwestern corner of the parish to a high of over 

230 ft above NGVD 29 northeast of Clinton (fig. 1). The 

direction of groundwater flow in the Upland terrace aquifer 

in East Feliciana Parish largely corresponds to land-surface 

topography; the general direction of groundwater flow is 

southward, with localized flow towards stream valleys 

(Tomaszewski, 2011). 

State well-registration records listed 494 active water 

wells screened in the Upland terrace aquifer in East Feliciana 

Parish in 2015, including 428 domestic, 53 irrigation, 

11 public supply, and 2 industrial. Depths of these wells 

ranged from 21 to 273 ft below land surface, and reported 

yields ranged from 3 to 543 gallons per minute (gal/min). In 

2010, withdrawals from the Upland terrace aquifer in East 

Feliciana Parish totaled about 0.34 Mgal/d, and use categories 

included about 0.19 Mgal/d for rural domestic, 0.02 Mgal/d 

for livestock, and 0.13 Mgal/d for general irrigation (Louisiana 

Department of Natural Resources, 2015). 
laf15-0696_fig 03

0

0 5 KILOMETERS

5 MILES VERTICAL SCALE GREATLY EXAGGERATED

Freshwater in sand

Saltwater in sand—Saltwater 

 contains greater than 250 milligrams 

 per liter chloride

Clay

Hydrogeologic contact—Defines boundary

 between conjoined or merged aquifers

Lithologic contact—Separates clay 

 and sand layers. Dashed where 

 approximate. Queried where uncertain

?

Hydrogeologic contact—Defines approximate

 boundary between aquifers or aquifer systems

EXPLANATION

“2,000-foot” sand

EAST BATONROUGE PARISH

EAST FELICIANAPARISH

Catahoula aquifer

“2,800-foot”

sand

“2,400-foot” sand

“2,000-foot”

sand

“1,700-foot” sand

“1,500-foot” sand

“1,200-foot” sand

“1,000-foot” sand

“800-foot” sand

GENERALIZED SURFACE PROFILE

?

?

“1,500-foot” sand

“2,800-foot”

sand

“1,000-foot” sand

Upland terrace aquifer

?

?

?

?

BEND IN

SECTION

BEND IN

SECTION

“2,400-foot” sand

FEET

200

NGVD 29

-200

-400

-600

-800

-1,000

-1,200

-1,400

-1,600

-1,800

-2,000

-2,200

-2,400

-2,600

-2,800

-3,000

-3,200

400

FEET

200

NGVD 29

-200

-400

-600

-800

-1,000

-1,200

-1,400

-1,600

-1,800

-2,000

-2,200

-2,400

-2,600

-2,800

-3,000

-3,200

400

A’

SOUTH

A

NORTH

Chicot equivalent

aquifer system

Evangeline equivalent aquifer system

Jasper equivalent aquifer system

Catahoula aquifer

(source well-log data limited to approximately this depth) 

Figure 3. Generalized north-to-south hydrogeologic section 

through East Feliciana Parish, Louisiana (modified from Griffith, 

2003). Trace of section shown on figure 1.

The Evangeline Equivalent Aquifer System

The aquifers composing the Evangeline equivalent 

aquifer system in East Feliciana Parish are the “800-foot”; 

“1,000-foot”; “1,200-foot”; “1,500-foot”; and “1,700-foot” 

sands of the Baton Rouge area (fig. 3). These aquifers contain 

freshwater and comprise fine- to coarse-grained sand. The 

altitude of the base of the aquifer system ranges from over 

300 ft below NGVD 29 near the northern parish line to about 

800–1,300 ft below NGVD 29 near the southern parish line 

(fig. 3) (Griffith, 2003). 

In 2003, water levels in wells screened in the 

“1,500-foot” and “1,700-foot” sands ranged from about 165 ft 

above NGVD 29 near the northeastern parish line to about 

45 ft below NGVD 29 in the extreme southwestern corner of 

the parish. The direction of groundwater flow was generally 

to the southwest towards pumping centers in East Baton 

Rouge Parish (Prakken, 2004). Water levels in the “1,200-

foot” sand at well EF-61 (site number 305144091010901), 

located in the town of Clinton (fig. 1), declined about 8 ft 

from 1995 to 2008, changed little between 2008 and 2013, 

and then rose about 5 ft from 2013 to 2015 (fig. 4).

State well-registration records listed 269 active water 

wells screened in the Evangeline equivalent aquifer system 

in East Feliciana Parish in 2015, including 237 domestic, 

17 irrigation, 11 public supply, and 4 industrial. Depths of 

these wells ranged from 100 to 1,122 ft below land surface, 

and reported yields ranged from 8 to 1,108 gal/min. In 2010, 

withdrawals from the Evangeline equivalent aquifer system 

in East Feliciana Parish were about 0.29 Mgal/d (table 1), and 

use categories included about 0.15 Mgal/d for public supply, 

0.02 Mgal/d for industry, 0.07 Mgal/d for rural domestic, and 

0.05 Mgal/d for general irrigation (Louisiana Department of 

Natural Resources, 2015). 

The Jasper Equivalent Aquifer System

The aquifers composing the Jasper equivalent aquifer 

system in East Feliciana Parish are the “2,000-foot”; 

“2,400-foot”; and “2,800-foot” sands of the Baton Rouge 

area (fig. 3), generally contain freshwater, and are generally 

composed of fine- to coarse-grained sand. The altitude of the 

base of the aquifer system is not well defined but is probably 

from greater than 1,500 ft below NGVD 29 near the northern 

parish line to about 1,900–2,300 ft below NGVD 29 near the 

southern parish line (fig. 3) (Griffith, 2003). 

In 2006, the general direction of groundwater flow in 

the “2,800-foot” sand in East Feliciana Parish was to the 

southwest towards a pumping center in northwestern East 

Baton Rouge Parish. Water levels at wells screened in the 

“2,800-foot” sand in 2006 ranged from about 60 ft above 

NGVD 29 in the extreme northeastern corner of the parish 

to about 40 ft below NGVD 29 in the extreme southwestern 

corner (Fendick, 2007). Water levels at well EF-185 (site 

number 304959091093001), located in west-central East 

Feliciana Parish (fig. 1) and screened in the “2,800-foot” 

sand, declined about 10 ft between 1996 and 2005 but 

changed little between 2005 and 2015 (fig. 4). 

State well-registration records listed 20 active water 

wells screened in the Jasper equivalent aquifer system in 

East Feliciana Parish in 2015, including 18 public supply, 

1 domestic, and 1 industrial. Depths of these wells ranged 

from 1,051 to 2,012 ft below land surface, and reported yields 

ranged from 205 to 1,507 gal/min. In 2010, withdrawals from 

the Jasper equivalent aquifer system in East Feliciana Parish 

were about 2.12 Mgal/d (table 1), and use categories included 

about 2.10 Mgal/d for public supply and 0.02 Mgal/d for 

industry (Louisiana Department of Natural Resources, 2015). 
The Catahoula Aquifer

The Catahoula aquifer 

underlies all of East Feliciana 

Parish; however, the extent and 

thickness are not well defined. 

Freshwater is present in the 

upper part of the aquifer in 

northern areas of the parish, 

with saltwater present in 

most of the aquifer near the 

southern parish line (fig. 3). 

Near the town of Norwood, the 

Catahoula aquifer is present at 

a depth of about 1,500–2,100 ft 

below NGVD 29. The major 

sand layers of the aquifer 

can reach a thickness of over 

450 ft, with saltwater present 

in the lowest of these layers 

(Morgan, 1963). 

State well-registration 

records listed seven active 

water wells screened in the 

Catahoula aquifer in East 

Feliciana Parish in 2015. All 

of these wells were used for 

public supply. Depths of these 

wells ranged from 1,966 to 

2,218 ft below land surface, 

and reported yields ranged from 150 to 1,500 gal/min. In 2010, 

withdrawals from the Catahoula aquifer in East Feliciana Parish 

totaled about 0.76 Mgal/d (table 1) and were used for public 

supply (Louisiana Department of Natural Resources, 2015). 

Groundwater Quality

A statistical summary of selected water-quality 

characteristics for freshwater samples collected from 26 wells 

screened in the Chicot equivalent aquifer system, 29 wells 

screened in the Evangeline equivalent aquifer system, and 

27 wells screened in the Jasper equivalent aquifer system in East 

Feliciana Parish is presented in table 3. Median values for each 

set of samples were found to be soft2

 with respect to hardness 

and did not exceed the U.S. Environmental Protection Agency’s 

Secondary Maximum Contaminant Levels (SMCLs)3 for color or 

concentrations of iron, manganese, and dissolved solids. Median 

pH ranged from 5.7 to 8.3 standard units, with values generally 

increasing with aquifer depth. Median temperature ranged 

from 20.0 to 28.2 degrees Celsius (from 68.0 to 82.8 degrees 

Fahrenheit), with temperature values also increasing with aquifer 

depth. Based on sample values, localized iron concentrations can 

greatly exceed the SMCL in the Evangeline and Jasper equivalent 

aquifer systems, and localized manganese concentrations can 

Figure 4. Water levels in well EF-61 screened in the ”1,200-foot” sand and well EF-185 screened in the 

“2,800-foot” sand in East Feliciana Parish, Louisiana (see fig. 1 for well locations; U.S. Geological Survey, 

2015a). Land surface and water levels are in feet (ft) above the National Geodetic Vertical Datum of 1929 

(NGVD 29).

laf15-0696_fig 04

Year

Water level, in feet 

10

20

30

40

110

120

130

140

1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 2016

Well: EF-185 Aquifer: "2,800-foot" sand

Altitude of land surface: 228 ft above NGVD 29

Well depth: 1,514 ft below land surface

Well: EF-61 Aquifer: "1,200-foot" sand

Altitude of land surface: 210 ft above NGVD 29

Well depth: 305 ft below land surface

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), aesthetic effects (such as taste, odor, 

or color), or technical effects (such as damage to water equipment or reduced 

effectiveness of treatment for other contaminants) of drinking water. SMCLs were 

established as guidelines by the U.S. Environmental Protection Agency (2016). 

greatly exceed the SMCL in the Jasper equivalent aquifer system. 

Limited water-quality data indicated that water from the Catahoula 

aquifer is soft and alkaline and does not exceed SMCLs for iron, 

manganese, or dissolved-solids concentrations (U.S. Geological 

Survey, 2012).

Surface-Water Resources 

Surface-water resources in East Feliciana Parish are located 

within the Lower Mississippi-Baton Rouge Basin (Hydrologic 

Unit Code [HUC] 080701) and the Lake Maurepas Basin (HUC 

080702). The Lake Maurepas Basin is divided into two subbasins 

within the parish. The eastern approximately three-fourths of the 

parish is within the Amite River subbasin (HUC 08070202), and 

most of the western approximately one-fourth is within the Bayou 

Sara-Thompson subbasin (HUC 08070201), which runs parallel 

to the western parish border. Only the extreme southwestern 

tip of the parish is within the Lower Mississippi-Baton Rouge 

Basin and subbasin (HUC 08070100) (fig. 1). In 2010, about 

0.25 Mgal/d of surface water were withdrawn from miscellaneous 

streams (table 1) in East Feliciana Parish for livestock and general 

irrigation (table 2). 

Lower Mississippi-Baton Rouge Basin

The Lower Mississippi-Baton Rouge Basin receives drainage 

from Thompson Creek; however, more than 40 percent of the 

conterminous United States drains into the Lower MississippiBaton Rouge Basin, contributing to an average streamflow of the 

Mississippi River near Red River Landing (site number 07373291; 

fig. 1 index map) of about 460,000 cubic feet per second (ft3

/s) for 

the period 1928–76 (Wells, 1980; Demcheck and others, 2004). 
Table 3. Summary of selected water-quality characteristics for freshwater in the Chicot, Evangeline, and Jasper equivalent aquifer 

systems in East Feliciana Parish, Louisiana (U.S. Geological Survey, 2012).

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

CaCO3, calcium carbonate; μg/L, microgram per liter; <, less than; SMCL, Secondary Maximum Contaminant Level established by the U.S. Environmental 

Protection Agency (2016); NA, not applicable]

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

 Chicot equivalent aquifer system, 1940–2001 (26 wells)

Median 20.0 5 82 5.7 12 10 <10 <10 66

10th percentile 19.4 <1 45 5.1 6 5.2 <10 <3 41

90th percentile 21.5 10 225 6.3 38 24 200 69 157

Number of samples 18 18 20 24 26 26 13 12 22

Percentage of samples 

that do not exceed 

SMCLs

NA 94 NA 4 NA 100 100 67 100

 Evangeline equivalent aquifer system, 1950–2006 (29 wells)

Median 21.4 10 116 6.5 22 5.0 190 10 92

10th percentile 20.5 0 62 6.1 10 3.8 <20 <10 57

90th percentile 23.8 26 191 7.1 40 10 1,700 75 176

Number of samples 16 19 23 27 25 25 10 6 16

Percentage of samples 

that do not exceed 

SMCLs

NA 63 NA 56 NA 100 60 67 100

 Jasper equivalent aquifer system, 1956–2005 (27 wells)

Median 28.2 5 264 8.3 8 4.0 70 20 202

10th percentile 25.2 0 156 6.7 3 2.3 <20 <10 141

90th percentile 30.0 20 415 8.9 25 5.9 1,900 170 260

Number of samples 18 23 25 26 27 27 15 13 25

Percentage of samples 

that do not exceed 

SMCLs

NA 78 NA 62 NA 100 60 54 100

SMCLs

NA 15 NA 6.5–8.5 NA 250 300 50 500

Lake Maurepas Basin

The Amite subbasin contains the Amite River, Beaver Creek, 

Comite Creek, Comite River, Horton Bayou, Pretty Creek, Sandy 

Creek, and Redwood Creek (fig. 1). The Amite River forms in 

the northeastern corner of East Feliciana Parish from the junction 

of the West Fork and East Fork Amite Rivers, which originate 

in Mississippi, and flows southward along the eastern parish 

boundary. The annual average streamflow of the Amite River near 

Darlington (site number 07377000; fig. 1) was about 906 ft3

/s 

during 1951–2014 from a drainage area of 580 square miles (mi2

) 

(U.S. Geological Survey, 2015b). The Comite River drains the 

central part of the parish and receives streamflow from Comite 

Creek, Pretty Creek, and other smaller drainages. The annual 

average streamflow for the Comite River near Olive Branch (site 

number 07377500; fig. 1) was 231 ft3

/s for the period 1943–2014 

from a drainage area of 145 mi2

 (U.S. Geological Survey, 2015b). 

The Bayou Sara-Thompson subbasin covers a much smaller 

segment of land running approximately parallel to the western 

border of East Feliciana Parish. The primary stream draining this 

subbasin is Thompson Creek, which is fed by smaller creeks and 

drainages in East Feliciana Parish and eventually flows into the 

Mississippi River. 

Surface-Water Quality

Water samples taken from the Mississippi River near St. 

Francisville (site number 07373420) from 1978 to 2010 and 

the Amite River near Darlington (site number 07377000) from 

1961 to 1976 (fig. 1; table 4) were found to have median values 

for pH and concentrations of chloride, sulfate, and iron that 

did not exceed SMCLs. Dissolved-oxygen samples from the 

Mississippi River were generally greater than 5 mg/L, which is 

considered the minimum value for a diverse population of fresh, 
Table 4. Summary of selected water-quality characteristics for the Mississippi and Amite Rivers near East Feliciana Parish, Louisiana 

(U.S. Geological Survey, 2012).

[Values are in milligrams per liter, except as noted. °C, degree Celsius; μS/cm, microsiemen per centimeter; SU, standard unit; μg/L, microgram per liter; CaCO3, 

calcium carbonate; <, less than; SMCL, Secondary Maximum Contaminant Level established by the U.S. Environmental Protection Agency (2016); 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)

Mississippi River near St. Francisville, 1978–20101

Median 380 8.6 7.8 150 38 12 17 20 44 <10

10th percentile 298 6.5 7.3 110 31 8.7 11 14 32 <5

90th percentile 473 11.8 8.0 180 46 16 27 28 66 40

Number of samples 412 402 407 400 400 405 346 410 409 393

Percentage of samples that 

do not exceed SMCLs NA NA 100 NA NA NA NA 100 100 100

Amite River near Darlington, 1961–762

Median 36 9.0 6.6 8 2.0 0.6 3.9 4.2 0.6 180

10th percentile 34 NA 6.0 6 1.6 0.2 3.0 3.4 0.1 NA

90th percentile 42 NA 6.9 10 2.8 0.8 4.8 6.4 2.1 NA

Number of samples 16 4 16 16 16 16 16 16 16 2

Percentage of samples that 

do not exceed SMCLs NA NA 75 NA NA NA NA 100 100 100

SMCLs

NA NA 6.5–8.5 NA NA NA NA 250 250 300

1

Site number 07373420 (see fig. 1).

2

Site number 07377000 (see fig. 1).

warmwater biota, including sport fish (Louisiana Department 

of Environmental Quality, 2008). Mississippi River water 

quality varies seasonally because of the rate and distribution of 

precipitation and land-use patterns. Water-quality constituents, 

such as agricultural pesticides and nutrients, generally have the 

highest concentrations in June and July, representing the “spring 

flush” that results from the runoff of upstream applications of 

these pesticides and nutrients (Demcheck and others, 2004). 

References Cited 

Demcheck, D.K.; Tollett, R.W.; Mize, S.V.; Skrobialowski, S.C.; Fendick, R.B., Jr.; Swarzenski, C.M.; and Porter, Stephen, 2004, Water quality in the Acadian-Pontchartrain Drainages, Louisiana and Mississippi, 1999–2001: U.S. Geological 

Survey Circular 1232, 41 p.

Fendick, R.B., Jr., 2007, Louisiana ground-water map no. 22—Generalized potentiometric surface of the Amite aquifer and 

“2,800-foot” sand of the Baton Rouge area in southeastern in Louisiana, June–August 2006: U.S. Geological Survey 

Scientific Investigations Map 2984, 1 sheet, accessed March 2, 2012, at http://pubs.usgs.gov/sim/2984/.

Griffith, J.M., 2003, Hydrogeologic framework of southeastern Louisiana: Louisiana Department of Transportation and 

Development Water Resources Technical Report no. 72, 21 p., 18 pls. 

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.

Louisiana Department of Environmental Quality, 2008, Environmental Regulatory Code, Title 33, Part IX, Subpart 1: Baton 

Rouge, Louisiana Department of Environmental Quality, accessed June 9, 2009, at http:www.deq.louisiana.gov/portal/

tabid/1674/Default.aspx.

Louisiana Department of Natural Resources, 2015, Strategic Online Natural Resources Information System (SONRIS): 

Louisiana Department of Natural Resources database, accessed May 18, 2015, at http://sonris.com/.

Morgan, C.O., 1963, Ground-water resources of East Feliciana and West Feliciana Parishes, Louisiana: Louisiana Department 

of Public Works, 58 p. 

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

Survey in cooperation with the Louisiana Department 

of Transportation and Development. 

By Vincent E. White and Lawrence B. Prakken

For additional information, contact: 

Director, USGS Lower Mississippi-Gulf Water Science Center

3535 S. Sherwood Forest Blvd., Suite 120

Baton Rouge, LA 70816

E-mail: gs-w-lmg_center_director@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) https://doi.org/10.3133/fs20163069