U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2016–3066

January 2017

Prepared in cooperation with the Louisiana Department of Transportation and Development 

Water Resources of Calcasieu Parish, Louisiana

Introduction

Information concerning the availability, use, and quality 

of water in Calcasieu 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 on the availability, past and current 

use, use trends, and water quality from groundwater and surfacewater 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://

dx.doi.org/10.5066/F7P55KJN) are the primary sources of the 

information presented here. 

In 2010, about 223.7 million gallons per day (Mgal/d) 

of water were withdrawn in Calcasieu Parish, including about 

136.7 Mgal/d from surface-water sources and 87.0 Mgal/d from 

groundwater sources.1

 Withdrawals for industrial use accounted 

for the majority (156.5 Mgal/d) of total water withdrawn 

(tables 1–2). Other categories of use included public supply, 

power generation, rural domestic, livestock, rice irrigation, 

general irrigation, and aquaculture. Water-use data collected 

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

water withdrawals peaked in 1970 at about 1,020 Mgal/d. The 

generally downward trend in water withdrawals from 1960 to 

2010 is largely attributable to reductions in withdrawals for 

industrial use and rice irrigation. 

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. 

90

165

14

27 12 171

101

109

90

27

§ ̈¦10

§ ̈¦10

§ ̈¦210

TEXAS

LOUISIANA

Williamson Creek aquifer

(Jasper aquifer

system) 

Evangeline

aquifer

Chicot

aquifer system

A

A′

Base modified from U.S. Geological Survey digital data

Albers Equal-Area Conic projection

North American Datum of 1983 0 10 20 MILES

0 10 20 KILOMETERS

West Fork Calcasieu

subbasin

Lower Calcasieu

subbasin

Upper Calcasieu subbasin

Lower Sabine

subbasin

Mermentau

subbasin

ALLEN PARISH

BEAUREGARD

PARISH

JEFFERSON DAVIS

PARISH

CAMERON PARISH

CALCASIEU PARISH CALCASIEU PARISH Gulf Intracoastal Waterway

Bayou ChoupiqueBayou

Choupique

Sabine River Diversion DystemSabine River Diversion System

Sabine River Sabine River

Calcasieu River

Grand

 Lake

Ca lcasieu River

Bayou Serpent Bayou Serpent

Sabine

Lake

Calcasieu Lake

Moss Lake

Prien Lake

Lake

Charles Charles

Black

Lake

West Fork

Calcasieu RiverIndian Bayou Indian Bayou

Bayou Lacassine

Houston River

Vinton

Sulphur Westlake

Prien

Lake Charles Iowa

Moss BluffMoss Bluff

DeQuincy

Kinder

08015500

08030500 08015900 08015900

Cu-771

Cu-787

Cu-767

93°00'

93°20' 93°40'

30°20'

30°00'

A A'

08015500

08015900

Cu-771

Approximate altitude of base of fresh groundwater, 

 in feet below National Geodetic Vertical Datum of 1929 

 (NGVD 29) (modified from Smoot, 1988)—Deepest 

 freshwater contained within Chicot aquifer system 

 and underlying aquifers, as noted

 400 to 599

 600 to 799

 800 to 999

 1,000 to 1,499

 1,500 to 1,999

 2,000 to 2,499

Approximate boundary of area showing

 deepest freshwater contained within

 underlying Evangeline aquifer

Approximate boundary of area showing

 deepest freshwater contained within

 underlying Williamson Creek aquifer 

 (Jasper aquifer system)

River subbasin boundary

Line of section (see fig. 3)

Well and well number 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 5)

EXPLANATION

GULF OF MEXICO

CALCASIEU

PARISH TEXAS

ARKANSAS MISSISSIPPI

LOUISIANA

Figure 1. Location of study area, Calcasieu Parish, Louisiana.
Table 1. Groundwater withdrawals, in million gallons per day, by source and use category in Calcasieu Parish, Louisiana, 2010 (B.P. 

Sargent, U.S. Geological Survey, written commun., 2015). 

[<, less than]

Use category

Chicot aquifer system Evangeline 

aquifer "200-foot" and Total by use

upper sand "500-foot" sand "700-foot" and lower sand

Undifferentiated 

sand Shallow sand

Public supply 1.19 21.62 2.10 0.04 0.00 0.79 25.73

Industrial 1.16 39.35 <0.01 0.72 0.00 0.00 41.23

Power generation 0.00 6.46 0.00 0.00 0.00 0.00 6.46

Rural domestic 1.56 0.53 0.00 0.02 0.11 0.00 2.23

Livestock 0.10 0.03 0.01 0.04 0.01 0.00 0.20

Rice irrigation 3.71 2.29 0.63 0.95 0.32 0.00 7.90

General irrigation 0.18 0.11 0.02 0.00 0.03 0.00 0.34

Aquaculture 0.58 0.58 0.58 0.00 1.16 0.00 2.90

Total by source 8.49 70.97 3.35 1.77 1.63 0.79 87.00

Table 2. Surface-water withdrawals, in million gallons per day, by source and use category in Calcasieu Parish, Louisiana, 2010 (B.P. 

Sargent, U.S. Geological Survey, written commun., 2015).

Use category Calcasieu River Gulf Intracoastal 

Waterway

Sabine River

Diversion System

Miscellaneous 

streams Total by use

Public supply 0.00 0.00 0.50 0.00 0.50

Industrial 76.17 0.01 39.12 0.00 115.30

Power generation 0.05 0.00 14.46 0.00 14.51

Livestock 0.00 0.00 0.00 0.30 0.30

Rice irrigation 0.00 0.00 0.00 3.77 3.77

Aquaculture 0.00 0.00 0.00 2.34 2.34

Total by source 76.22 0.01 54.07 6.42 136.72

0

100

200

300

400

500

600

700

800

900

1,000

1,100

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 Calcasieu Parish, Louisiana, 

1960–2010 (Sargent, 2011).

Groundwater Resources

Fresh groundwater (water with a chloride concentration of 

250 milligrams per liter [mg/L] or less) is available in Calcasieu 

Parish in several different aquifers to varying depths, depending on 

location. The base of freshwater in Calcasieu Parish ranges from 

about 400 feet (ft) below the National Geodetic Vertical Datum of 

1929 (NGVD 29) to almost 2,500 ft below NGVD 29. The deepest 

freshwater is north of DeQuincy within the Williamson Creek 

aquifer. In the rest of the roughly northern quarter of the parish, the 

base is present at depths from about 700 to 2,000 ft or more below 

NGVD 29 within the Evangeline aquifer. In the southern threefourths of the parish, the base of freshwater ranges in depth from 

about 500 to 800 ft below NGVD 29 and is within the Chicot aquifer 

system (fig. 1; Smoot, 1988). 

The Chicot Aquifer System

The Chicot aquifer system is an important regional aquifer 

system underlying most of southwestern Louisiana. The aquifer 

system crops out and receives recharge in parishes to the north and 

northeast of Calcasieu Parish where the aquifer system is largely 

composed of one, major, undifferentiated sand. The undifferentiated 

sand thickens and deepens to the south and, near the northern border 

of Calcasieu Parish (fig. 1), becomes subdivided into a complex 

series of sand layers by clay confining layers. West of about the 
longitude of the town of Iowa (fig. 1), these divisions consist of the 

“200-foot,” “500-foot,” and “700-foot” sands of the Lake Charles area 

(fig. 3). East of this longitude, these divisions consist of the Chicot 

aquifer upper and lower sands, which are hydraulically connected to 

the “200-foot” and “700-foot” sands, respectively (fig. 3). 

 A surficial confining layer of clay restricts infiltration of 

precipitation into the groundwater system throughout the parish. 

The surficial confining layer thickness ranges from 40 ft in small 

areas in northwestern and northeastern Calcasieu Parish to 280 ft in 

the south-central part of the parish (Sargent, 2004). Within the 

surficial confining clay are scattered sand streaks, sand lenses, 

and sand layers collectively named the “shallow sand unit of the 

Chicot aquifer system.”

The primary aquifers in the parish are the “200-foot,” “500-

foot,” and “700-foot” sands (table 1), and these aquifers share similar 

characteristics but are present at varying depths. The “200-foot” sand 

generally grades from fine to medium sand at the top to a coarse sand 

or gravel at the base (Harder, 1960). The top of the sand is present 

at depths of zero to 50 ft above NGVD 29 near the northeastern 

corner of the parish and greater than 300 ft below NGVD 29 in the 

southwestern corner of the parish (Harder, 1960). The “500-foot” sand 

generally grades from fine sand at the top to coarse sand and gravel 

near the base (Harder, 1960). The top of the “500-foot” sand is present 

at less than 400 ft below NGVD 29 in northern areas of the parish and 

reaches over 600 ft below NGVD 29 in the southeastern corner of the 

parish (Nyman, 1984). The base of the “500-foot” sand ranges from 

greater than 400 ft below NGVD 29 in the northern part of the parish 

to greater than 800 ft below NGVD 29 in the southeastern corner of 

the parish (Nyman, 1989). The “700-foot” sand is generally tan to 

grayish and grades from fine sand at the top to coarse sand at the base 

(Harder, 1960). The top of the “700-foot” sand is present at depths of 

less than 400 ft below NGVD 29 in the northern part of the parish and 

reaches depths exceeding 800 ft below NGVD 29 in the southeastern 

corner of the parish. The base of the lower sand and “700-foot” sand 

ranges from greater than 400 ft in the northern tip of the parish to 

greater than 1,000 ft in the southeastern corner of the parish (Nyman, 

1989). In 2015, more than 4900 active wells were screened in Chicot 

aquifer system in Calcasieu Parish, with most of them being screened 

in these three primary aquifers from depths of 13 to 849 ft, with yields 

of up to 5,471 gallons per minute (Louisiana Department of Natural 

Resources, written commun., 2015) (table 3). 

Water levels in wells in all three sands in Calcasieu Parish 

showed similar spatial and temporal patterns. In 2011–12, water 

levels in wells screened in the “200-foot,” “500-foot,” and “700-

foot” sands in Calcasieu Parish ranged from highs of approximately 

7.6 ft above, 2.4 ft below, and 14.1 ft below NGVD 29, respectively, 

to lows of 49.9 ft below, 79.6 ft below, and 69.6 ft below NGVD 

29, respectively (U.S. Geological Survey, 2016a). Spatially, water 

levels in wells in all three sands were lowest near the Calcasieu River 

in the Lake Charles metropolitan area, corresponding well to the 

documented movement of groundwater toward this area (Nyman, 

1984; Lovelace, 1998). Water levels in wells have varied in similar 

ways over time and have risen in general by as much as 20 ft since 

the 1970s (fig. 4), because of decreased pumping.

Groundwater Quality

Freshwater samples collected from 111 wells screened in the 

“200-foot” sand, 239 wells screened in the “500-foot” sand, and 

63 wells screened in the “700-foot” sand had median hardness 

values in the moderately hard range.2

 Over 90 percent of samples 

in each aquifer did not exceed the U.S. Environmental Protection 

Agency’s Secondary Maximum Contaminant Levels (SMCLs)3

for pH. Over 80 percent of samples in each aquifer did not exceed 

the SMCL for dissolved-solids concentrations. Median values for 

iron concentrations were below the SMCL in the “200-foot” sand 

and greatly exceeded the SMCL in the “500-foot” and “700-foot” 

sands (table 4). 

Saltwater (water with a chloride concentration greater than 

250 mg/L) is present in both local and widespread areas within 

the Chicot aquifer system in Calcasieu Parish. At the base of the 

“200-foot” sand and in the upper sand, saltwater is present along 

most of the southern parish boundary, in the southeastern corner 

of the parish, and in a localized area near Iowa. At the base of the 

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 (2016). 

EXPLANATION

Lithologic contact—Separates

 clay and sand layers

Bend in section

Clay

Freshwater in sand

Saltwater in sand—Saltwater contains

 greater than 250 milligrams per liter chloride

Source well-log data unavailable in this area

-1,200

-1,000

-800

-600

-400

-200

NGVD 29

FEET FEET

-1,200

-1,000

-800

-600

-400

-200

NGVD 29

A A’

WEST EAST

0

0

5

5 10 KILOMETERS

10 MILES

“200-ft” sand

“500-ft” sand

“700-ft” sand

Upper sand

Lower sand

Land surface not shown

Chicot aquifer system

Surficial confining layer

Figure 3. Generalized west-to-east hydrogeologic section A–A’ through Calcasieu Parish, Louisiana (modified from Nyman, 

1984). Trace of section shown on figure 1.
Table 3. Active registered wells in the Chicot aquifer system in Calcasieu Parish in 2015 (Louisiana Department of Natural Resources, 

written commun., 2015).

Shallow sand “200-foot” and

upper sands “500-foot" sand “700-foot” andlower sands

Undifferentiated 

sand

Domestic 276 2,985 935 15 20

Industrial 5 35 121 12 4

Irrigation 17 120 93 16 7

Public supply 7 142 120 13 4

Power generation 0 0 6 0 0

Total 305 3,282 1,275 56 35

Well depth range (feet 

below land surface) 13–305 18–590 130–740 445–849 70–460

Yield range (gallons

per minute) 2–50 4–5,471 5–5,000 20–4,700 30–4,000

Well: Cu-771

Aquifer: "200-foot" sand

Altitude of land surface: 18 ft, NGVD 29

Well depth: 241 ft below land surface

Well: Cu-787

Aquifer: "500-foot" sand

Altitude of land surface: 4 ft, NGVD 29

Well depth: 734 ft below land surface

Well: Cu-767

Aquifer: "700-foot" sand

Altitude of land surface: 11 ft, NGVD 29

Well depth: 850 ft below land surface

Year

1960 1970 1980 1990 2000 2010

-100

-90

-80

-70

-60

-50

-40

-30

-20

Water level, in feet 

Figure 4. Water levels in 

wells Cu-771, Cu-787, and 

Cu-767 screened in the 

“200-foot” sand, “500-

foot” sand and “700-foot” 

sand of the Chicot aquifer 

system in Calcasieu 

Parish, Louisiana (see 

fig. 1 for well locations; 

U.S. Geological Survey, 

2016a). Land surface and 

water levels are in feet 

(ft) relative to the National 

Geodetic Vertical Datum of 

1929 (NGVD 29).

“500-foot” sand, saltwater is present along much of the southern 

parish boundary, in the southeastern corner of the parish, and in 

three small isolated areas at or near industrial facilities between Lake 

Charles and Sulphur. At the base of the “700-foot” sand and in the 

lower sand, saltwater is present in the southern two-thirds of the 

parish. The “700-foot” sand contains only saltwater along most of the 

southern parish boundary (Harder, 1960; Nyman, 1989). 

Surface-Water Resources 

Surface-water resources in Calcasieu Parish are available 

in two regional drainage basins: the Calcasieu-Mermentau Basin 

(Hydrologic Unit Code [HUC] 080802), which covers the majority 

of the parish, and the Sabine Basin (HUC 120100), which is present 

along the Sabine River on the western side of the parish (U.S. 

Geological Survey, 2016b). In 2010, about 136.7 Mgal/d of surface 

water were withdrawn in Calcasieu Parish for public supply, industry, 

power generation, livestock, rice irrigation, and aquaculture use 

(table 2). Over 95 percent of surface-water withdrawals came from 

the Calcasieu River (76.22 Mgal/d) and Sabine River Diversion 

System (54.07 Mgal/d) (table 2). 

Calcasieu-Mermentau Basin

The Calcasieu-Mermentau Basin is subdivided into six subbasins, 

four of which are present in Calcasieu Parish. These subbasins are 

the West Fork Calcasieu (HUC 08080205), Upper Calcasieu (HUC 

08080203), Lower Calcasieu (HUC 08080206), and Mermentau 

(HUC 08080202) (fig. 1).

The West Fork Calcasieu and Upper Calcasieu subbasins cover 

most of the northern half of the parish and drain south into the Lower 

Calcasieu subbasin, which extends to and drains southward into the 

Gulf of Mexico. The West Fork Calcasieu subbasin is drained by 

the Houston River, West Fork Calcasieu River, Indian Bayou, and 

many other small streams. The Houston River and Indian Bayou 

are tributaries of West Fork Calcasieu River, which flows into the 

Calcasieu River just upstream of Lake Charles. The Upper Calcasieu 
Table 4. Summary of selected water-quality characteristics of freshwater in the Chicot aquifer system in Calcasieu Parish, Louisiana 

(U.S. Geological Survey, 2016a). 

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

unit; CaCO3, calcium carbonate; μg/L, microgram per liter; NA, not applicable; SMCL, Secondary Maximum Contaminant Level established by the U.S. 

Environmental Protection Agency (2016)]

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

“200-foot” sand of the Lake Charles area, 1940–2009 (111 wells) 

Median 22.0 1 483 7.5 110 32 230 140 280

10th percentile 20.3 0 364 6.9 66 16 30 60 232

90th percentile 23.3 10 1,090 7.9 200 120 2,800 450 509

Number of samples 79 28 95 68 73 106 46 48 63

Percentage of 

samples that do 

not exceed SMCLs

NA. 93 NA. 93 NA. 100 59 6 86

“500-foot” sand of the Lake Charles area, 1940–2006 (239 wells) 

Median 23.5 5 404 7.2 110 34 1,000 350 258

10th percentile 22.0 0 301 6.8 80 22 180 240 214

90th percentile 25.0 20 677 7.6 140 98 2,200 480 436

Number of samples 127 99 188 143 155 237 97 91 104

Percentage of 

samples that do 

not exceed SMCLs

NA. 87 NA. 99 NA. 100 19 1 92

“700-foot” sand of the Lake Charles area, 1939–95 (63 wells) 

Median 24.0 5 548 7.4 100 68 920 390 332

10th percentile 22.0 0 341 6.7 66 26 260 160 263

90th percentile 25.5 36 952 8.2 140 200 2,100 500 558

Number of samples 32 29 49 40 46 62 15 20 30

Percentage of 

samples that do 

not exceed SMCLs

NA. 72 NA. 92 NA. 100 13 0 83

SMCLs

NA. 15 NA. 6.5–8.5 NA. 250 300 50 500

subbasin is drained by the Calcasieu River whose tributaries include 

Bayou Serpent and many other small streams. The annual average 

discharge upstream of Calcasieu Parish for the Calcasieu River 

near Kinder (site number 08015500) (fig. 1) during 1922–2014 

was 2,524 cubic feet per second (ft3/s) (U.S. Geological Survey, 

2016a) from a drainage area of 1,700 square miles (mi2). The Lower 

Calcasieu subbasin in Calcasieu Parish contains the Calcasieu River, 

Bayou Choupique, the Gulf Intracoastal Waterway, and many other 

small streams. Multiple lakes are found along the Calcasieu River in 

Calcasieu Parish. 

The Mermentau subbasin is located in the southeastern corner of 

the parish and is drained by Bayou Lacassine and other small streams. 

Sabine Basin

The Sabine Basin contains only the Lower Sabine subbasin in 

Calcasieu Parish (HUC 12010005) and is drained by the Sabine River. 

The Sabine River drains a strip of land along the western border of 

the parish and is connected to the interior of Calcasieu Parish by 

canals. In the north-central part of the parish, the Sabine River 

Diversion System conveys water by way of canal from the Sabine 

River eastward to several industries located near Westlake and 

Sulphur. The system also supplies water for municipal use and 

irrigation (Sabine River Authority, 2007). In the southern part of 

the parish, the Gulf Intracoastal Waterway runs roughly east-west 

from the Texas border, across the Calcasieu River just south of 

Moss Lake, then southeastward into Cameron Parish. The annual 

average discharge of the Sabine River near Ruliff, Tex. (site 

number 08030500), (fig. 1) during 1961–2015 was 7,626 ft3/s from 

a drainage area of about 9,330 mi2 (U.S. Geological Survey, 2016a). 

Surface-Water Quality

Water samples collected from the Calcasieu River near Lake 

Charles (site number 08015900) during 1968–78 and from the 

Sabine River near Ruliff, Tex., during 1967–2000 have median 
hardness values in the soft range (table 5). Over 80 percent of 

samples did not exceed the SMCL for iron concentrations, and 

median pH values were also within the SMCLs. Dissolved-oxygen 

concentrations were generally greater than 5 mg/L, which is 

considered the minimum value for a diverse population of fresh, 

warmwater biota, including sport fish (Louisiana Department of 

Environmental Quality, 2008). 

References Cited 

Harder, A.H., 1960, The geology and ground-water resources of Calcasieu Parish, Louisiana: U.S. Geological 

Survey Water-Supply Paper 1488, 102 p., accessed December 6, 2012, at http://pubs.er.usgs.gov/publication/

wsp1488.

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.

Lovelace, J.K., 1998, Distribution of saltwater in the Chicot aquifer system in the Calcasieu Parish area, 

Louisiana, 1995-96: Louisiana Department of Transportation and Development Water Resources Technical 

Report no. 62, 59 p.

Nyman, D.J., 1984, The occurrence of high concentrations of chloride in the Chicot aquifer system of southwestern Louisiana: Louisiana Department of Transportation and Development, Office of Public Works Water 

Resources Technical Report no. 33, 75 p.

Nyman, D.J., 1989, Quality of water in freshwater aquifers in southwestern Louisiana: Louisiana Department of 

Transportation and Development Water Resources Technical Report no. 42, 22 p., 28 pls. 

Sabine River Authority, 2007, Diversion canal history: Sabine River Authority, accessed September 26, 2011, at 

http://12.6.56.180/index.php?q=content/history-0. 

Sargent, B.P., 2004, Thickness of the Chicot aquifer system surficial confining unit and location of shallow 

sands, southwestern Louisiana: Louisiana Department of Transportation and Development Water Resources 

Technical Report no. 73, 29 p. 

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

Water Resources Special Report no. 17, 135 p. 

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 November 2, 2011,

at http://pubs.er.usgs.gov/publication/wri864314.

U.S. Environmental Protection Agency, 2016, Secondary Drinking Water Standards: Guidance for Nuisance 

Chemicals, accessed April 13, 2016, at https://www.epa.gov/dwstandardsregulations/secondary-drinkingwater-standards-guidance-nuisance-chemicals. 

 U.S. Geological Survey, 2016a, National Water Information System—Web interface: Accessed January 28, 

2016, at http://waterdata.usgs.gov/nwis.

U.S. Geological Survey, 2016b, Science in Your Watershed: U.S. Geological Survey Web page, accessed May 

18, 2016, at http://water.usgs.gov/wsc/reg/08.html.

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

Table 5. Summary of selected water-quality characteristics for the Calcasieu and Sabine Rivers, Calcasieu Parish, Louisiana (U.S. Geological 

Survey, 2016a). 

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

microgram per liter; 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)

Calcasieu River near Lake Charles, 1968–781

Median 98 7.4 6.7 18 4.2 1.7 12 18 6.0 140

10th percentile 43 5.4 5.8 10 2.5 0.8 4.3 5.1 3.7 80

90th percentile 3,360 10.0 7.2 330 26 65 520 980 130 360

Number of samples 49 48 49 49 49 49 49 49 49 15

Percentage of samples 

that do not exceed 

SMCLs

NA. NA. 69 NA. NA. NA. NA. 86 94 87

Sabine River near Ruliff, Texas 1967–20002

Median 142 7.8 6.8 29 7.4 2.4 15 18 12 150

10th percentile 92 6.4 6.2 18 4.9 1.3 9.2 11 7.2 70

90th percentile 197 10.2 7.2 38 10 3.3 21 27 19 360

Number of samples 538 190 302 291 291 291 213 520 519 106

Percentage of samples 

that do not exceed 

SMCLs

NA. NA. 80 NA. NA. NA. NA. 100 100 87

SMCLs

NA. NA. 6.5–8.5 NA. NA. NA. NA. 250 250 300

1

Site number 08015900 (see fig. 1). 

2

Site number 08030500 (see fig. 1). 

ISSN 2327-6916 (print) ISSN 2327-6932 (online) https://doi.org/10.3133/fs20163066