U.S. Department of the Interior

U.S. Geological Survey

Prepared in cooperation with the

Llano Estacado Underground Water Conservation District, 

Sandy Land Underground Water Conservation District, and South Plains Underground Water Conservation District

Scientific Investigations Map 3355

Sheet 2 of 2

laf16-CMSJ00-0739_fig 09

Brownfield

Denver City

Seagraves

Seminole

Plains

380

385

385

380

62

82

180

214

137

83

214

62

TEXAS

NEW MEXICO

GAINES

COUNTY

HOCKLEY

COUNTY

TERRY

COUNTY

YOAKUM

COUNTY

102°20' 102°40' 103°00'

33°20'

33°00'

32°40'

!

!

!

!

!!

!

!

!!

!

!

!

!!

!

!

!

!

!

!

!

Well location and median dissolved-solids concentration,

in milligrams per liter

! ≤ 500

! > 500 to 1,000

! > 1,000 to 3,000

! > 3,000 (not present)

EXPLANATION

Edwards-Trinity aquifer downdip extent

Underground water conservation district boundary

Llano Estacado Underground Water Conservation District

Sandy Land Underground Water Conservation District

South Plains Underground Water Conservation District

0 5 10 15 MILES

0 5 10 15 KILOMETERS

Base modified from U.S. Geological Survey 1:250,000-scale to 1:2,000,000-scale digital data,

World Geodetic System of 1984, Universal Transverse Mercator (UTM) Zone 13

Figure 10. Early development period (1930–60) dissolved-solids concentrations measured in samples collected from 

wells completed in the Ogallala aquifer in and near Gaines, Terry, and Yoakum Counties, Texas. laf16-CMSJ00-0739_fig 10

Brownfield

Denver City

Seagraves

Seminole

Plains

380

385

385

380

62

82

180

214

137

83

214

GAINES

COUNTY

HOCKLEY

COUNTY

TERRY

YOAKUM COUNTY

COUNTY

33°20'

33°00'

32°40'

EXPLANATION

Edwards-Trinity aquifer downdip extent

Underground water conservation district boundary

Llano Estacado Underground Water Conservation District

Sandy Land Underground Water Conservation District

South Plains Underground Water Conservation District

Well location and median dissolved-solids concentration,

in milligrams per liter

! ≤ 500

! > 500 to 1,000

! > 1,000 to 3,000

! > 3,000

102°20' 102°40' 103°00'

TEXAS

NEW MEXICO

62

!

!

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!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!!

!

0 5 10 15 MILES

0 5 10 15 KILOMETERS

Base modified from U.S. Geological Survey 1:250,000-scale to 1:2,000,000-scale digital data,

World Geodetic System of 1984, Universal Transverse Mercator (UTM) Zone 13

Figure 11. Recent period (2005–15) dissolved-solids concentrations measured in samples collected from wells 

completed in the Ogallala aquifer in and near Gaines, Terry, and Yoakum Counties, Texas. laf16-CMSJ00-0739_fig 11

Brownfield

Denver City

Seagraves

Seminole

Plains

380

385

385

380

62

82

180

214

137

83

214

62

GAINES

COUNTY

HOCKLEY

COUNTY

TERRY

COUNTY

YOAKUM

COUNTY

33°20'

33°00'

32°40'

EXPLANATION

Edwards-Trinity aquifer downdip extent

Underground water conservation district boundary

Llano Estacado Underground Water Conservation District

Sandy Land Underground Water Conservation District

South Plains Underground Water Conservation District

! ≤ 2.5

! > 2.5 to 5.0

! > 5.0 to 7.5 (not present)

! > 7.5 to 10

! > 10 (not present)

Well location and median nitrate concentration,

in milligrams per liter

!

!

!

!

!

!

!

!

!

!

! !

!

!

!

!

!

!

!

102°20' 102°40' 103°00'

TEXAS

NEW MEXICO

0 5 10 15 MILES

0 5 10 15 KILOMETERS

Base modified from U.S. Geological Survey 1:250,000-scale to 1:2,000,000-scale digital data,

World Geodetic System of 1984, Universal Transverse Mercator (UTM) Zone 13

Figure 12. Early development period (1930–60) nitrate concentrations measured in samples collected from wells 

completed in the Ogallala aquifer in and near Gaines, Terry, and Yoakum Counties, Texas. laf16-0739_fig12

Brownfield

Denver City

Seagraves

Seminole

Plains

380

385

385

380

62

82

180

214

137

83

214

62

GAINES

COUNTY

HOCKLEY

COUNTY

TERRY

COUNTY

YOAKUM

COUNTY

33°20'

33°00'

32°40'

102°20' 102°40' 103°00'

EXPLANATION

Edwards-Trinity aquifer downdip extent

Underground water conservation district boundary

Llano Estacado Underground Water Conservation District

Sandy Land Underground Water Conservation District

South Plains Underground Water Conservation District

! ≤ 2.5

! > 2.5 to 5.0

! > 5.0 to 7.5

! > 7.5 to 10

! > 10

Well location and median nitrate concentration,

in milligrams per liter

!

!

!

!

!

! !

!

!!

!

!

!

!

!

!

!

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!

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!

!

TEXAS

NEW MEXICO

0 5 10 15 MILES

0 5 10 15 KILOMETERS

Base modified from U.S. Geological Survey 1:250,000-scale to 1:2,000,000-scale digital data,

World Geodetic System of 1984, Universal Transverse Mercator (UTM) Zone 13

Figure 13. Recent period (2005–15) nitrate concentrations measured in samples collected from wells completed in the 

Ogallala aquifer in and near Gaines, Terry, and Yoakum Counties, Texas.

laf16-0739_fig13_11824_ds

Measurement date

1955 1965 1975 1985 1995 2005 2015

1,400

1,200

1,000

800

600

400

200

Dissolved-solids concentration

0

, in milligrams per liter

Well 11824

laf16-0739_fig13_11825_ds

Measurement date

1955 1965 1975 1985 1995 2005 2015

1,400

1,200

1,000

800

600

400

200

Dissolved-solids concentration

0

, in milligrams per liter

Well 11825

laf16-0739_fig13_11524_ds

Measurement date

1955 1965 1975 1985 1995 2005 2015

1,400

1,200

1,000

800

600

400

200

Dissolved-solids concentration

0

, in milligrams per liter

Well 11524

laf16-0739_fig13

Brownfield

Denver City

Seagraves

Seminole

Plains

380

385

385

380

62

82

180

214

137

83

214

62

GAINES

COUNTY

HOCKLEY

COUNTY

TERRY

COUNTY

YOAKUM

COUNTY

33°20'

33°00'

32°40'

102°20' 102°40' 103°00'

EXPLANATION

Edwards-Trinity aquifer downdip extent

Underground water conservation district boundary

Llano Estacado Underground Water Conservation District

Sandy Land Underground Water Conservation District

South Plains Underground Water Conservation District

Well location and identifier (table 11)

Dissolved-solids concentration, in milligrams per liter (table 11)

Nitrate concentration, in milligrams per liter (table 11)

11524

TEXAS

NEW MEXICO

11824

11825

11524

0 5 10 15 MILES

0 5 10 15 KILOMETERS

Base modified from U.S. Geological Survey 1:250,000-scale to 1:2,000,000-scale digital data,

World Geodetic System of 1984, Universal Transverse Mercator (UTM) Zone 13

laf16-0739_fig13_11824_n

Measurement date

1955 1965 1975 1985 1995 2005 2015

20

18

16

14

12

10

8

6

4

2

0

Nitrate concentration, in milligrams per liter

Well 11824

laf16-0739_fig13_11825

Measurement date

1955 1965 1975 1985 1995 2005 2015

20

18

16

14

12

10

8

6

4

2

0

Nitrate concentration, in milligrams per liter

Well 11825

laf16-0739_fig13_11524_n

Measurement date

1955 1965 1975 1985 1995 2005 2015

20

18

16

14

12

10

8

6

4

2

0

Nitrate concentration, in milligrams per liter

Well 11524

Figure 14. Well locations and water-quality sampling results of dissolved-solids and nitrate concentrations measured in samples 

collected from wells completed in the Ogallala aquifer in and near Gaines, Terry, and Yoakum Counties, Texas.

laf16-0739_fig14

Brownfield

Denver City

Seagraves

Seminole

Plains

380

385

385

380

62

82

180

214

137

83

214

62

GAINES

COUNTY

HOCKLEY

COUNTY

TERRY

COUNTY

YOAKUM

COUNTY

33°20'

33°00'

32°40'

102°20' 102°40' 103°00'

EXPLANATION

Edwards-Trinity aquifer downdip extent

Underground water conservation district boundary

Llano Estacado Underground Water Conservation District

Sandy Land Underground Water Conservation District

South Plains Underground Water Conservation District

! ≤ 500

! > 500 to 1,000

! > 1,000 to 3,000

! > 3,000 (not present)

Well location and median dissolved-solids concentration,

in milligrams per liter

!!!!!

!

!

!

!

!

!

!

!

!

TEXAS

NEW MEXICO

0 5 10 15 MILES

0 5 10 15 KILOMETERS

Base modified from U.S. Geological Survey 1:250,000-scale to 1:2,000,000-scale digital data,

World Geodetic System of 1984, Universal Transverse Mercator (UTM) Zone 13

Figure 15. Early development period (1930–60) dissolved-solids concentrations measured in samples collected from wells 

completed in the Edwards-Trinity aquifer in and near Gaines, Terry, and Yoakum Counties, Texas.

laf16-0739_fig15

Brownfield

Denver City

Seagraves

Seminole

Plains

380

385

385

380

62

82

180

214

137

83

214

62

GAINES

COUNTY

HOCKLEY

COUNTY

TERRY

COUNTY

YOAKUM

COUNTY

33°20'

33°00'

32°40'

102°20' 102°40' 103°00'

EXPLANATION

Edwards-Trinity aquifer downdip extent

Underground water conservation district boundary

Llano Estacado Underground Water Conservation District

Sandy Land Underground Water Conservation District

South Plains Underground Water Conservation District

! ≤ 500 (not present)

! > 500 to 1,000

! > 1,000 to 3,000

! > 3,000 (not present)

Well location and median dissolved-solids concentration,

in milligrams per liter

!

!

!

! !!

!

!

!

!

!

!

TEXAS

NEW MEXICO

0 5 10 15 MILES

0 5 10 15 KILOMETERS

Base modified from U.S. Geological Survey 1:250,000-scale to 1:2,000,000-scale digital data,

World Geodetic System of 1984, Universal Transverse Mercator (UTM) Zone 13

Figure 16. Recent period (2005–15) dissolved-solids concentrations measured in samples collected from wells completed 

in the Edwards-Trinity aquifer in and near Gaines, Terry, and Yoakum Counties, Texas.

laf16-0739_fig16

Brownfield

Denver City

Seagraves

Seminole

Plains

380

385

385

380

62

82

180

214

137

83

214

62

GAINES

COUNTY

HOCKLEY

COUNTY

TERRY

COUNTY

YOAKUM

COUNTY

33°20'

33°00'

32°40'

102°20' 102°40' 103°00'

EXPLANATION

Edwards-Trinity aquifer downdip extent

Underground water conservation district boundary

Llano Estacado Underground Water Conservation District

Sandy Land Underground Water Conservation District

South Plains Underground Water Conservation District

! ≤ 2.5

! > 2.5 to 5.0 (not present)

! > 5.0 to 7.5 (not present)

! > 7.5 to 10 (not present)

! > 10 (not present)

Well location and median nitrate concentration,

in milligrams per liter

!

!

!

!

!

! !

!

!

!

!

!

TEXAS

NEW MEXICO

0 5 10 15 MILES

0 5 10 15 KILOMETERS

Base modified from U.S. Geological Survey 1:250,000-scale to 1:2,000,000-scale digital data,

World Geodetic System of 1984, Universal Transverse Mercator (UTM) Zone 13

Figure 17. Early development period (1930–60) nitrate concentrations measured in samples collected from wells 

completed in the Edwards-Trinity aquifer in and near Gaines, Terry, and Yoakum Counties, Texas.

laf16-0739_fig17

Brownfield

Denver City

Seagraves

Seminole

Plains

380

385

385

380

62

82

180

214

137

83

214

62

GAINES

COUNTY

HOCKLEY

COUNTY

TERRY

COUNTY

YOAKUM

COUNTY

33°20'

33°00'

32°40'

102°20' 102°40' 103°00'

EXPLANATION

Edwards-Trinity aquifer downdip extent

Underground water conservation district boundary

Llano Estacado Underground Water Conservation District

Sandy Land Underground Water Conservation District

South Plains Underground Water Conservation District

! ≤ 2.5

! > 2.5 to 5.0

! > 5.0 to 7.5

! > 7.5 to 10 (not present)

! > 10 (not present)

Well location and median nitrate concentration,

in milligrams per liter

!

!

!

!

!

! !

! ! !

!

!

TEXAS

NEW MEXICO

0 5 10 15 MILES

0 5 10 15 KILOMETERS

Base modified from U.S. Geological Survey 1:250,000-scale to 1:2,000,000-scale digital data,

World Geodetic System of 1984, Universal Transverse Mercator (UTM) Zone 13

Figure 18. Recent period (2005–15) nitrate concentrations measured in samples collected from wells completed in the 

Edwards-Trinity aquifer in and near Gaines, Terry, and Yoakum Counties, Texas.

Changes Between Early Development (1930–60) and Recent (2005–15) Groundwater-Level Altitudes and 

Dissolved-Solids and Nitrate Concentrations In and Near Gaines, Terry, and Yoakum Counties, Texas

By

Jonathan V. Thomas, Andrew P. Teeple, Jason D. Payne, and Scott Ikard

2016

Any use of trade, product, or firm names in this publication is for descriptive purposes only

and does not imply endorsement by the U.S. Government

For sale by U.S. Geological Survey, Information Services, Box 25286, Federal Center, 

Denver, CO 80225, 1–888–ASK–USGS

Digital files available at http://dx.doi.org/10.3133/sim3355

Suggested citation: Thomas, J.V., Teeple, A.P., Payne, J.D., and Ikard, Scott, 2016, Changes 

between early development (1930–60) and recent (2005–15) groundwater-level altitudes and 

dissolved-solids and nitrate concentrations in and near Gaines, Terry, and Yoakum Counties, 

Texas: U.S. Geological Survey Scientific Investigations Map 3355, 2 sheets, pamphlet,

http://dx.doi.org/10.3133/sim3355.

ISSN 2329-1311 (print)

ISSN 2329-132X (online)

http://dx.doi.org/10.3133/sim3355