Information in the El Paso, Water Studies, 1903-80

) .'7 DALLAS PUBLIC LIBRARY ak 3cc

Report 300

Summary of Hydrologic Information in the El Paso, Texas, Area, With Emphasis on Ground- Water Studies, 1903-80

August 1987 Texas &tate Oouets NOV 7 8i(

Dallas Public Library

rEOp~

X86408366

TEXAS WATER DEVELOPMENT BOARD

REPORT 300

SUMMARY OF HYDROLOGIC INFORMATION IN THE

EL PASO, TEXAS, AREA, WITH EMPHASIS ON

GROUND-WATER STUDIES, 1903-80

D. E. White U.S. Geological Survey

This report was prepared by the U.S. Geological Survey under cooperative agreement with the City of El Paso Public Service Board and the Texas Water Development Board

August 1987 TEXAS WATER DEVELOPMENT BOARD

M. Reginald Arnold II, Executive Administrator

Louie Welch, Chairman Stuart S. Coleman, Vice Chairman Glen E. Roney George W. McCleskey Charles W. Jenness Thomas M. Dunning

Authorization for use or reproduction of any original material contained in this publication, i.e., not obtained from other sources, is freely granted. The Board would appreciate acknowledgement.

Published and distributed by the Texas Water Development Board Post Office Box 13231 Austin, Texas 78711

ii ABSTRACT

Significant development of ground water in the El Paso area started in the early 1900's; pumping gradually increased to the early 1950's and has since accelerated commensurate with. the area's rapid population growth. In 1980, withdrawals of ground water for municipal, industrial, and military supplies totaled 164,354 acre-feet within the El Paso, Fort Bliss, and Ciudad Juarez, Mexico metropolitan area, and adjacent areas in Texas and New Mexico. Most of the water, 132,652 acre-feet, was pumped from the Hueco bolson, the principal aquifer. The Mesilla bolson and Rio Grande alluvium in the lower Mesilla Valley supplied 27,461 and 4,241 acre-feet respectively.

The cumulative 1906 through 1980 withdrawals of ground water from the Hueco bolson metro area total 3.0 million acre-feet-about 2.2 million acre-feet has been pumped in the United States and 0.8 million acre-feet in the Republic of Mexico. These withdrawals have caused water levels to decline about 130 feet in the downtown sections of El Paso and Ciudad Juarez. In January 1980 the theoretically recoverable volume of freshwater in storage within the Texas part of the Hueco bolson metro area was estimated at 10.0 million acre-feet. Dissolved-solids concentrations in recent samples from Hueco bolson wells averaged 642 milligrams per liter in the Texas part of the metropolitan area and 736 milligrams per liter in Ciudad Juarez. Concentrations are increasing at an average-annual rate of about 10 milligrams per liter in Texas and 30 milligrams per liter in Juarez.

Ground water in the lower Mesilla Valley is pumped for municipal and industrial supply and also for supplemental crop irrigation during years of inadequate surface-water supply in the Rio Grande. The 1979-80 withdrawals in the valley averaged about 31,000 acre-feet per year. Most of the water, about 21,000 to 22,000 acre-feet per year, was pumped from shallow, medium depth, and deep wells in the Canutillo field. Dissolved-solids concentrations from recent samples from Canutillo wells ranged from 252 to 1,854 milligrams per liter.

Flow in the Rio Grande is diverted for crop irrigation in the United States and the Republic of Mexico, and for limited municipal supply in El Paso. The flow is regulated by releases from reservoirs in New Mexico and varies widely in both quantity and quality (dissolved-solids concentrations). During 1943-80, the flow at El Paso ranged from 57,481 acre-feet in 1956 to 631,800 acre-feet in 1943 and averaged about 317,000 acre-feet per year.

iii 1

- 6 m i 2

a ,sia ma a 4

m a e, a vM

E 1 -11 m i

a a i TABLE OF CONTENTS

Page

ABSTRACT...... i

INTRODUCTION ...... 1

Purpose and Scope ...... 2

PeiuInetga ......

Metric Conversions...... 5

DEVE LOPMENT OF WATER R ESOURCES...... 6

LOWE R M ESILLA VALLEY AND MESILLA BOLSON...... 11

Ground-Water Hydrology ...... 13

Water Quality...... 16

Ground-Water Availability...... 18

H UECO BOLSON-EL PASO VALLEY...... 21

Ground-Water Hydrology...... 28

Water Quality...... 34

Old Mesa Well Field...... 41

Agricultural Irrigation Project In Northeast El Paso...... 51

Ground-Water Availability...... 60

R IO GRANDE...... 61

SUMMARY AND CONCLUSIONS ...... 61

BIBLIOGRAPHY...... 70

V TABLE OF CONTENTS-Continued Page TABLES

1. Ground-Water Withdrawals, El Paso County, Texas, and Adjacent Areas in New Mexico and Mexico, 1965-80...... 12

2. Dissolved-Solids Concentrations in Water From Shallow Wells in the City of El Paso Canutillo Well Field, Lower Mesilla Valley, Texas ...... 22

3. Dissolved-Solids Concentrations in Water From Medium- Depth Wells in the City of El Paso Can utillo Well field, Lower Mesilla Valley, Texas...... 23

4. Dissolved-Solids Concentrations in Water From Deep Wells in the City of El Paso Canutillo Well Field, Lower Mesilla Valley, Texas ...... 27

5. Cross Reference of State and Local Numbers of Wells in the Vicinity of the Old Mesa Well Field ...... 49

6. Summary of Quantity and the Dissolved-Solids Concentrations in Irrigation Water Applied to a 622-Acre Dairy Farm in Northeast El Paso...... 52

7. Estimates and Projections of Freshwater in Storage in the Texas Portion of the Hueco Bolson, 1903-2030...... 62

8. Summary of Flow and Concentrations of Dissolved Solids in the Rio Grande at El Paso, 1943-80 ...... 63

FIGUR ES

1. Map Showing Location and Physiography of El Paso Area ...... 2

2. Graph Showing Annual Precipitation in El Paso, 1856 to 1980...... 3

3. Map Showing Well-Field Areas and Ground-Water Withdrawals, Lower Mesilla Valley, 1979...... 7

4. Map Showing Well-Field Areas and Ground-Water Withdrawals, Hueco Bolson, 1979...... 9

vi TABLE OF CONTENTS-Continued Page

5. Graph Showing Annual Surface-Water Diversions From the Rio Grande for the City of El Paso Municipal Use, 1943-80...... 11

6. Graph Showing Estimated Withdrawals and Use of Ground Water in the Lower Mesilla Valley, Texas and New Mexico, 1945-80...... 14

7a-c. Graphs Showing Withdrawals of Ground Water From the Canutillo Well Field and Hydrographs of Observation Wells, 1952-80:

a. Shallow Wells...... 15

b. Intermediate Wells...... 15

c. Deep Wells...... 15

8. Hydrographs of 10 Shallow Observation Wells in the Lower Mesilla Valley...... 17

9. Map Showing Location of 15 Water-Level Observation Wells in the Lower Mesilla Valley with Hydrographs Shown in Figures 7a-c and 8 ...... 18

10. Map Showing Estimated Predevelopment Altitude of the Water Table in the Lower Mesilla Valley ...... 19

11. Graph Showing Recovery of Water Levels in Response to Shutdown of Pumping in the Canutillo Well Field, January 1976...... 21

12. Map Showing Estimated Thickness of Sediments Containing Freshwater in the Lower Mesilla Valley...... 25

13. Graph Showing Withdrawals of Ground Water From the Hueco Bolson Metro Area, 1906-80 and 10-Year Census Population for the City of El Paso ...... 29

14. Map Showing Approximate Altitude of Water Levels in the Hueco Bolson, 1903 and January 1980 ...... 31

15. Hydrographs of 13 Wells in the Hueco Bolson...... 35

vii TABLE OF CONTENTS-Continued Page

1 6-28. Maps Showing:

16. Location of 13 Water-Level Observation Wells and 3 Early Municipal and Military Production Wells in the Hueco Bolson...... 37

17. Approximate Altitude of the Water Levels in the Shallow Aquifer in the Downtown El Paso-Chamizal Area, 1936, 1967, and January 1980...... 39

18. Areas of Similar Dissolved-Solids Concentrations in Samples from Wells in the Hueco Bolson, 1979-81...... 43

19. Average Annual Change in Dissolved-Solids Concentrations in Samples From Wells in the Hueco Bolson Metro Area ...... 45

20. Location of Selected Wells in the Vicinity of the Old Mesa Well Field...... 48

21. Location of Abandoned Wells in the Old Mesa Well Field ...... 48

22. Dissolved-Solids Concentrations in Samples Pumped From Wells in the Vicinity of the Old Mesa Well Field, 1979-81 ...... 50

23. Dissolved-Solids Concentrations in Samples Bailed From Wells in the Vicinity of the Old Mesa Well Field, 1980 ...... 50

24. Total Nitrogen Concentrations in Samples Pumped From Selected Wells in the Vicinity of the Old Mesa Well Field, 1980-81 ...... 50

25. Total Nitrogen Concentrations in Samples Bailed From Wells in the Vicinity of the Old Mesa Well Field, 1980 ...... 50

26. Water Levels in Selected Wells in the Vicinity of the Old Mesa Well Field...... 51

27. Dissolved-Solids Concentrations in Samples From Wells in the Vicinity of the Old Mesa Well Field-Historic Data...... 51

28. Location of an Abandoned 622-Acre Dairy Farm and Selected Wells in Northeast El Paso...... 53

viii TABLE OF CONTENTS-Continued

Page

29. Graph Showing the Quantity and Dissolved-Solids Concentrations of Irrigation Water Applied to the Dairy Farm...... 53

30. Map Showing Depths to Water and Approximate Water- Table Elevations for Early Data and January 1980, in Northeast El Paso and Adjacent Areas in New Mexico...... 55

31. Graphs Showing the Variations in Dissolved Solids, Chloride, and Sulfate Concentrations in Water From Wells in the Vicinity of the Dairy Farm, 1957-80 ...... 57

32a-c. Maps Showing Approximate Areal Distribution of the Dissolved-Solids Concentration in Water From Wells in the Vicinity of the Dairy Farm:

a. 1966...... :...... 59

b. 1974-76...... 59

c. 1980...... 59

33. Map Showing the Concentrations of Nitrate in Water From Wells in the Vicinity of the Dairy Farm, 1980 and 1981...... 59

34. Graph Showing Recorded and Projected Withdrawals of Ground Water From the Hueco Bolson Metro Area, 1970-2030...... 61

35. Map Showing the Approximate Altitude of the Base of Freshwater in the Hueco Bolson, 1973...... 65

36. Map Showing the Estimated Thickness of Sediments Containing Freshwater in the Hueco Bolson, January 1980...... 67

ix P s.

4 -1 ae a

n p

m 1

a SUMMARY OF HYDROLOGIC INFORMATION IN THE EL PASO, TEXAS, AREA, WITH EMPHASIS ON GROUND-WATER STUDIES, 1903-80-

D. E. White U.S. Geological Survey

INTRODUCTION

The availability of water in the city of El Paso and Ciudad Juarez to meet the rapidly growing demands for industrial use and municipal supply concerns not only the residents, but also the State and Federal governments. The future of the international community and the Fort Bliss and Biggs Air Base military installations is likely to be dependent upon the use of ground water pumped in the area. Because of the limits of the freshwater resources of the area and their importance, the U.S. Geological Survey has been monitoring and investigating the water resources in the area in cooperation with the city of El. Paso Public Service Board and the Texas Water Development Board, or predecessor agencies, since the 1930's.

Located in the far western tip of Texas, the study area includes most of El Paso County and adjacent areas in New Mexico and Ciudad Juarez in Mexico. The location of the study area and regional physiography is shown in Figure 1. In this report the designated study area is frequently abbreviated as the El Paso area.

The climate of the El Paso area is typical of the arid to semiarid region of the southwestern United States and northern Mexico. The days are warm and the nights are cool. In late winter and early spring, high winds and blowing sand are common. The humidity is low and the evaporation rate is high, with the gross annual lake surface evaporation totaling about 80 inches.

The rate of evaporation in El Paso greatly exceeds the average annual rainfall of about 8.0 inches. Figure 2 shows the annual precipitation in El Paso for 1856 through 1980. During the period of continuous record starting in 1879, annual rainfall ranged from a low of 2.22 inches in 1891 to a high of 18.29 inches in 1884. During the 100-year period (1881-1980) rainfall averaged 8.43 inches. Alamogordo Purpose and SCOpe

The purpose of this report is to summarize Co* the development of the water resources of the

- - El Paso area, centering on the use of ground water for municipal, military, and industrial supply within the city of El Paso-Fort Bliss

La q Military Reservation and Ciudad Juarez metropolitan complex. Included are estimates of Approiateotndry - \FRANTLN TEXAS current withdrawals and reserves of fresh UNITD STATE - ground water and recent projections of future MEXICO Ciadad Jxare r'0 conditions. Due to availability of published ChstxoRey reports that contain detailed aquifer descrip- tions and tabulations of data, no effort is made to duplicate the information in these Stu publications. TEXAS

0 10 20 30 MILES Adpe*rmLga n at's, Locatian map Previous Investigations Figure 1.-Location and Physiographic Map Nmru tde aebe aeo of El Paso Area Nmru tde aebe aeo the water resources of the El Paso area. EarlV studies were by Slichter (1905), Richardson (1909), and Lippencott (1921). The geology and ground-water resources have been adequately described by Sayre and Livingston (1945), Knowles and Kennedy (1956), Leggat, Lowry, and Hood (1962), and more recent studies, which include Meyer and Gordon (1972), U.S. Bureau of Reclamation (1973), Bluntzer (1975), Gates and others (1978), Alvarez and Buckner (1980), and C. A. Wilson and others (1981).

Ground-water digital-model studies were made by Meyer (1976) and Knowles and Alvarez (1979) for the H ueco bolson, the principal aquifer. Muller and Price (1979) included the El Paso area in their Statewide projections of ground-water availability through 2030. The U.S. Water and Power Resources Service (1980) examined the water resources of the Elephant Butte Reservoir- Fort Quitman project which includes the El Paso area and projected future population growth and water use using several scenarios of ground- and surface-water allocation. Garza and others (1980) studied the potential for injection-well recharge with treated sewage effluent. Lee Wilson and Associates (1981) studied El Paso's water supply, projected water demand and potential supplies to the year 2080, and proposed alternatives for alleviating future shortages.

Alvarez and Buckner (1980) compiled records on wells, water levels, and water quality in the Texas part of the study area, and C. A. Wilson and others (1981) compiled records for the New Mexico part. Bluntzer (1975) compiled well data and pumpage records for Ciudad Juarez. These records and more current data are on file in the El Paso office of the Texas Water Development Board and in the Geological Survey field offices in El Paso, Texas, and Las Cruces, New Mexico.

A Geological Survey Regional Aquifer System Analysis (RASA) study of the southwest alluvial basins, including the Rio Grande in the El Paso area, is currently in progress (1983). During this investigation much of the data that has been collected in the area will be compiled and

- 2- 30H-

wC') 25 H- I C-) z z 20 0 I- 4 0~ C-) w IS a- -J 4 z Norcr z 4 10

0 . . . 1 / I 1856 1860 1865 1870 1875 1880 1885 1890 1895 1900 1905 1910 1915 1920 1925 1930 1935 1940 1945 1950 1955 1960 1965 1970 1975 1980

Figure 2 Annual Precipitation in El Paso, 1856 to 1980 s

m a

1 a digital model of the regional ground-water flow system in the Mesilla basin will be developed. The Geological Survey, in cooperation with the city of El Paso Public Service Board, Texas Water Development Board, and the Department of the Army (Fort Bliss), is also currently conducting a three-dimensional solute transport modeling project in the Hueco Bolson. This project is designed to understand better the potential for saline water encroachment into the freshwater part of the aquifer. Metric Conversions

Factors for converting inch-pound units of measurement to metric equivalents are given in the following table:

From Multiply by To obtain

inch 25.4 millimeter (mm)

foot 0.3048 meter (in)

mile 1.609 kilometer (kin)

square mile 2.590 square kilometer (kin2)

acre 4,047 square meter (in2 )

0.4047 hectare (ha)

gallon 3.785 liter (L)

acre-foot 1,233 cubic meter (in3 )

0.001233 cubic hectometer (hm3 )

million acre-feet 1.23 cubic kilometer (kin3 )

gallon per day 0.003785 cubic meter per day (gal/d) (m3/d) million gallons per day 0.04381 cubic meter per second (million gal/d) (m3/s) ton, short 0.9072 megagram (Mg) ton per acre-foot 736 milligrams per liter (mg/L)

- 5- DEVELOPMENT OF WATER RESOURCES

There are no records on the first well to be dug or drilled in the El Paso area. Irrigated farming was introduced by the Spaniards in 1659 when Fray Garcia de San Francisco y 'Zuniga founded "Our Lady of Guadalupe of El Paso" Mission in what is now downtown Ciudad Juarez. Water was diverted from the Rio Grande to irrigate crops and sustain the community, which grew up around the mission (U.S. Bureau of Reclamation, 1973). Shallow wells probably were dug to augment the supply during periods of little or no flow in the river. The available records indicate use of ground water in the El Paso area was negligible until there was a significant 'growth in population, starting in about 1900. For purposes of this report, the significant ground-water development began during 1903, although records on withdrawals are not available until 1906.

The 10-year census population for the city of El Paso from 1910-80 is summarized below. During that time, El Paso's population increased more than tenfold and the per capita use of water nearly tripled from 76 gallons per day to more than 200 gallons per day. Currently (1980), most of the water used for municipal and industrial supply in the El Paso area is pumped from deep wells in the Hueco bolson east of the Franklin and Sierra de Juarez (Juarez Mountains). Additional supplies are pumped from wells completed in the Mesilla bolson west of the mountains and from shallow wells in the Mesilla and El Paso-Juarez Valleys. Only a limited amount of surface water is used by the city of El Paso for municipal purposes. Flow in the Rio Grande is diverted primarily for irrigation of crops in the valleys. During years of inadequate surface-water supply, shallow wells in the Rio Grande alluvium are pumped to augment the diversions.

Year Population Year Population

1910 39,300 1950 130,000

1920 77,500 1960 279,000

1930 102,400 1970 322,500

1940 96,800 1980 425,100

Table 1 shows the source and use of ground water pumped in the El Paso area during 1965-80. The table does not include pumpage from privately owned domestic and irrigation wells in the Mesilla and El Paso Valleys. The location of the well fields in the lower Mesilla Valley and their estimated pumpage for 1979 are shown in Figure 3. Locations of well fields in the Hueco bolson area and their estimated pumpage for the same year are shown in Figure 4.

The total annual surface-water diversions from the Rio Grande for El Paso municipal supply are shown in Figure 5. The diversions started in 1943, and the rates of diversions in succeeding years have ranged from a low of 1,058 acre-feet during 1956, a year of extreme drought, to 20,057 acre-feet during 1980, a year of full surface-water allotments. The general increase since 1943 in the annual diversions reflects the acquisition by the El Paso Water Utilities of additional surface-water allotments.

- 6- l II

16*37' 30" 106* 30' Edge of flood plain

,Anthony NEW MEXICO 32*00' - - +- - - r - - ,- - - - - w*nn -Teeas------' - T EXA S C' 0 blic S 40 .. ~ La Tuna Federal Concoctions '-*~ 1'\ , Dairy farm -r 484- Edge of / annery- z ( flood pinMou stoinl Pas e - - La Tuna Federal Cor reclt ts rioa eo Institutional snro rop ir atian - 379 1000 (S 11eow Proler Internalional -'ndustria I L -' 31(Mediuam) 6llDeep) \ . \ ....-- Border Steel Edge of ,I~ Green Acres M.H. Park Industrial Public supply Mea-_ I 9 & -Wetway EXPL ANA TION - -. La Union -,'t - Metal processing t1~ Riverview Eslal s---- Industrial WELL FIELD-- Shows locations of wells 'j ublic supply E CI pumped in 1979, and approximate r 23 anutilkc field (EPWU) -J @00 Public "' boundary of field upply z 0 1147 IS 10 low) 0 10,364 :Medium) SWELL FIELD--Shows approximate boundary 10,765 (Deep) of field where wells are pumped, but are Ponderosa M.H. P - l O -Darbl n01 located individually on map 0 ~ Public supply shire Steel 34 Indus rial U, 0 IWestern Vil age MH Pa PRINCIPAL PRODUCING ZONES:. z ~ Publ y Canutillo School 0 SHALLOW AQUIFER Irrigation Loop 0 MEDIUM-DEPTH AQUIFER Gaslight M.H.Park A DEEP AQUIFER Public supply c 60

Canutlo field IEPWU-----Owner -s Public supply Use of wafer -Bonanza M.H. Park 10,364 ~Reported or estimated annual pumpage, Public supply 0 -- in acre-feet 20 NOTE: Pumpage from privately owned domestic and irrigation wells in the 31*52'30" - , w- a Rio Grande alluvium is not shown

Strauss ''

Santa Teresa-t ~ , Public supply , '-U 307

Santa Teresa , Irrigation N 1965, Golf Course 1416, Crop

Edge Edato floodplain \i 0 I 2 3 4 MILES Rio Grand I I 1 Industrial El'Ponro Electric) Bose from U. S. Geological Survey 2460 0 topographic quadrangles Sunla nd Pa - G/?ANDo eadow Vista, Anapra)l- Publi csupply 236 ______UNITED STATES / -''I NE MEXICO MEXICO CHIHUAHUA 106*37 '30" Sirra de Cristo Rey _

106* 30' Figure 3 Well-Field Areas and Ground-Water Withdrawals, Lower Mesilla Valley, 1979 s

n 105u30'0GO7' 106*30 3o" lO6*OC,

Camp, New Me xico \-Dona Ana (Fort Bliss) Military 68 __ _ 32nO7'3O0"- I32*O7'0

Hueco Camp (ABD rt Bliss)

Comnmunity 0 Chaparra, New Mexico

- A ~~Chaparra ,New Mexico

dt rn Plant (EPEC d~.EPtro Sand T EX A - __-

El Paso Natu xl Gas

'ii Rosebud Imports

Meso-Nevins (EPWU) Fo)O HUEGO I TANKS Public Supply :6 scoTanks 44 State Park I~blic Supply

30 CD TMin (Fort Bliss) ~ -I,

-- j-- CD I1*2'0" .- a-

.5 CD Biggs Air Bos ~ 'Aiport(EPWU) ' Evergreen Cemetoty 0 C's Puli supply 45RdArowlHPk 0 Post {~Fkr--t--- y Site Moniter (FifrI Bliss) Public supply .< MiItryMilitary 27J -2 0~ 1451 Cielci V ista Golt Coubrse 4'~?

0 56(EPWU) EPaso NaturalGas .5 0 L 'a-CarlsbadS.H Pork Public supply Pu li .pply Retiner'G 3"445 C | dsriPublic supply 16 Ch75za Naioa :P) 150 Chiato r'" t9 Cielo Vistl(E PWU) 75Public supply Tort Ext. M. H. Park El Paso Naturol Gas WIe lnt(P U - 74Public supply Industrial Pub lic suppl, E\L A S 64 5 - 4296 . "'Vista Hills Golt Course15 0 3!*45' ---.- -.- --. Irigtion CD SEastwood I(EP') .5 \ ' ublic supty Gote 0 4 O C u d 0 Lower vall (E U)/ 1 -4- OPublic suppl Wheeler (EPC WA, Horizon City) tJ~\~~0'0 1 03324 P/ublic supply 4 0~ .5 0 - Jux " ' - EM 281 0 53, 54ri zon g'o fCour Ir gotipli 34, I 106*3' C CD C, 0

0 C,, ~\ K 0 -Edg\ of ~

nO p/ Pfciid ri/ N nO

E XPL A NATIONN'

WELL FIEL D-- Shows locations of wells in 1979, and approximately OPumped boundary of fieldC

Meso-Nevins (EPWU)I- WeTI f ield name and owner Fbn Public supply Use of water310-

, 21,756 Annual numnage. Fn.hioirir (ECW N4) in aucre -feet 5 iD , Pu 106 o' \ blic Supply 594 T~ NOTE: Pumpage from privately owned ~ k domestic and irrigation wells in the .4>'4j ">'> Public supply Rio Grande alluvium is not shown

0 2 0 MILE:;

108 00 3s

a 6 9 re

a e P u F 4

m 4 e

']ir

9 4

4 a. -1

a 4 25-

2 0-

>0-

F5i Dvrsio.-nnof surface aeWtrDvrin rmteRoGad o h strtd inNoyme 19E4Ps3uncpl s,193

(194),3n 45 A.W 0so 55 thr 6091) 65 ate 7w0rpot 75cud da1980ln h

Figuesere 5AnaorraeWtets.son rmth i rnd o h The esila Vlle itye RofE Grado Municiphast se 943-80 la oso ndwst

The geonlog and ra ounwterirsouce The lower Mesilla Valley nd sia brolsohavNew beenxtiedbysLaeggnat Lowryn oo"E19P2s, dGaNte," anthersa (1978), Alvaez ankd MBunr (1980) and C.rr A. CisoR andothrthrsn1981).the trwerts inue dagtr o). Twel inste Tea n ofeioparts the valleyisrenpTcxiselnd The foll pr s nNw eio wi disusio rawsu lierually

d Te esilla Valeywof sttes.oGad rse hees ieo h eilablo n eto the FrlnandOgn Mountains. e ower Meilvalley extenmsdso southbafrok theNw Maeiceasd srtaelinusAnmtontEls deNorte,"sadthe.a etween nthe Fank Moun Ctass Sierracsanrmdh de Cristo Rey atd thelsnsrthernsti of thCad ureziurey 1) The eastdernf

the Rio Grande. The Sierra de Juarez consists entirely of Cretaceous sedimentary rocks intruded by Eocene dikes and sills.

The west side of the valley is bordered by La Mesa which is also called the West Mesa in New Mexico. La Mesa is the undissected surface of the Mesilla bolson that is underlain by basin fill of late Tertiary and Quaternary age.

Most of the Mesilla Valley and La Mesa is underlain by thick sections of alluvial basin fill probably underlain by thick sections of volcanic rocks. The basin fill of the Mesilla bolson is composed of clay, silt, sand, and gravel and includes equivalents of the Santa Fe Group of Miocene to Pleistocene age and the Rio Grande alluvium of Holocene age.

Ground water in the lower Mesilla Valley is storedin the unconsolidated Rio Grande alluvium and bolson fill deposits. These deposits are in hydraulic connection. Previous investigators have

- 11 - Table 1.-Ground-Water Withdrawals, El Paso County. Texas and Adjacent Areas in New Mexico and Mexico, 1965-80 USE OF WATER (acre-feet ) El Paso County, Texas Dona Ana County, New Mexico Mexico Grand Year Crop Public Crop Total total1 Mili- Indus- Recre- irriga- Sub- and Indus- Recre- irriga- Sub- U.S. Ciudad region ! Public tary trial ation tion total military trial ation tion total Juarez Other 1965 59,883 5,493 10,277 -569 8,933 85,155 2/85 2,441 0 2/412 2,938 88,093 16,822 Data 104,915 1966 51,082 5,765 10,413 569 8,209 76,038 97 2,121 0 560 2,778 78,816 16,806 not 95,622 1967 59,432 5,931 10,530 1,058 7,876 84,827 109 2,348 0 560 3,017 87,844 18,087 avail- 105,931 1968 58,530 6,052 10,005 1,058 7,084 82,729 121 2,359 0 560 3,040 85,769 19,709 able. 105,478 1969 62,650 5,748 10,664 1,139 6,445 86,646 145 2,573 0 560 3,278 89,924 22,151 112,075 1970 60,760 5,236 10,182 1,125 8,141 85,444 169 2,368 0 560 3,097 88,531 23,985 112,516 1971 70,903 5,313 11,015 1,125 7,880 96,236 194 2,273 0 560 3,027 99,263 29,473 128,736 1972 77,037 5,058 10,313 1,797 7,132 .101,337 230 3,304 0 560 4,094 105,431 32,412 137,843 1973 75,725 5,100 10,721 3,042 6,907 101,495 266 3,399 2/1,965 571 6,201 107,696 35,636 143,332 1974 73,659 5,103 10,503 2,469 6,968 98,702 307 3,356 1,965 571 6,199 104,901 37,294 142,195 1975 76,179 5,370 10,497 2,789 1,936 96,771 343 -3,457 1,965 674 6,439 103,210 39,529 142,739 1976 75,905 5,298 10,320 2,439 377 94,339 442 3,016 .1,965 827 6,250 100,589 42,111 142,700 1977 90,357 5,488 10,572 3,071 1,307 110,795 569 2,363 . 1,965 2,243 7,140 117,935 - 45,170 163,105 1978 95,781 5,190 10,176 2,675 20 113,842 614 2,768 1,965 2,247 7,594 121,436 49,175 170,611 1979 82,986 5,020 10,718 2,492 504 101,720 975 2,460 1,965 2,247 7,647 109,367 53,544 162,911 1980 81,823 5,013 9,894 2,439 880 100,049 1,071 3,078 1,965 2,381 8,496 108,545 55,808 164,353

SOURCE OF WATER (acre-feet) Hueco bolson Mesilla bolson Rio Grande alluvium Grand Year Metro area 3/ Total New El Paso Total New Total Mesilla Valley El Paso Valley Total total Texas Mexico metro Mexico Valley region Texas Mexico region Texas New Mexico Texas Mexico region region 1965 60,718 16,822 77,540 2/497 817 78,854 18,547 0 18,547 4,767 2,441 306 Data 7,514 104,915 1966 52,236 16,806 69,042 657 713 70,412 19,355 0 19,355 3,427. 2,121 306 not 5,854 95,621 1967 55,621 18,087 73,708 669 753 75,130 16,798 0 16,798 11,099 2,348 556 avail- 14,003 105,931 1968 61,771 19,709 81,480 711 1-,124 83,315 14,754 0 14,754 4,518' 2,359 562 able. 7,439 105,508 1969 67,777 22,151 89,928 705 1,432 92,065 14,222 0 1.4,222 2,643 2,573 571 5,787 112,074 1970 60,997 23,985 84,982 729 1,927 87,638 16,491 0 16,491 5,467 2,368 562 8,397 112,526 1971 64,964 29,473 94,437 754 2,283 97,474 18,083 0 18,083 10,345 2,273 562 13,180 128,737 1972 72,494 32,412 104,906 790 1,973 107,669 17,819 0 17,819 8,448 3,304 603 12,355 137,843 1973 75,896 35,636 111,532 - 837 2,214 114,583 15,917 2/1,965 17,882 7,014 3,399 455 10,868 143,333 1974 75,440 37,294 112,734 .878 2,556 .116,168 15,406 1,965 17,371 4,911 3,356 389 8,656 142,195

1975 72,040 39,529 111,569 1,017 2,695' 115,281 .16,664 I,965 18,629 5,010 3,457 .362 8,829 142,739 1976 70,991 42,111 113,102 1,192 2,983 117,277 18,799 2,042 20,841 1,209 3,016 358 4,583 142,701 1977 79,005 45,170 124,175 1,243 2,322 '127,740 23,318 3,534 26,852 5,774 2,364 376 8,514 163,106 1978 81,696 49,175 130,871 1,272 2,203 134,346 24,368 3,554 27,922 5,077 2,768 498 8,343 170,611 1979 74,464 53,544 128,008 1,263 1,973 131,244 23,563 3,924 27,487 1,324 2,460. 398 4,182 162,913 1980 73,423 55,808 129,231 1,264 2,157 132,652 23,308 4,153 27,461 767 3,079 395 4,241 164,354

1/ Withdrawals from domestic and irrigation wells in Rio Grande alluvium are unaccounted. 2/ Estimated. 3/ Hueco bolson metro area is arbitrarily defined as. having -large-scale ground-water development and a freshwater section generally exceeding 100 feet in thickness in 1980. separated the alluvium and bolson deposits into three aquifers based on differences in lithology, water levels, and water quality. These are the shallow aquifer, the medium-depth or intermediate aquifer, and the deep aquifer. This terminology was first applied to wells in the El Paso Water Utilities Canutillo field. There the shallow production wells are completed to depths of 200 feet or less. The medium-depth production wells have screens starting at 168-356 feet and extending to depths of 278-550 feet. The deep production wells are screened starting at depths of 512-650 feet and extending to depths of 900-1,200 feet.

Ground water in the lower Mesilla Valley is pumped for municipal and industrial supply and irrigation of crop land. Pumpage for irrigation is supplemental to diversions of flow from the Rio Grande; therefore, the rate of pumpage varies inversely with surface-water availability. Leggat and others (1962) reported that the amount of water pumped from wells in the lower Mesilla Valley was small before 1951 because most of the irrigated land had surface-water rights, and the supply released from storage in Elephant Butte Reservoir was adequate. In 1946, only two large-capacity wells were used. From 1946-50, the number of irrigation wells increased to 16, and by the end of 1954, about 250 wells had been drilled. These wells pumped an estimated 40,000 acre-feet of water to irrigate 15,000 acres of cotton and alfalfa.

The estimated annual withdrawal of ground water in the lower Mesilla Valley and Mesilla bolson from 1945 through 1980 is shown in Figure 6. The pumpage is separated by source and use of water. The amounts of ground water pumped in 1979 for municipal and industrial supply, and the locations of well fields and selected wells were shown earlier in Figure 3. The municipal and industrial pumpage for 1965-80 was also included in Table 1. Farmers in the lower Mesilla Valley received full surface-water allotments in both 1979 and 1980 so ground-water withdrawals went mainly for municipal and industrial supply and averaged about 31,000 acre-feet. Most of the withdrawals, about 21,000-22,000 acre-feet, came from wells in the El Paso Water Utilities Canutillo field.

The annual withdrawals from the three aquifers in the Canutillo well field during 1952-80, and hydrographs of observation wells are shown in Figures 7a-c. The shallow wells in the Canutillo field discharge into the Rio Grande. These wells are pumped during periods of release of irrigation water from Elephant Butte and Caballo Reservoirs in New Mexico. The well water, less transportation losses, is diverted along with the El Paso Water Utilities surface-water allotments at the Roberson-Umbenhauer treatment plant near downtown El Paso. The intermediate and deep wells, which pump better-quality water, are connected directly to the storage-distribution system.

Ground-Water Hydrology

Depths to water in wells in the lower Mesilla Valley vary both seasonally and annually. Water levels also vary at a particular location depending upon how deep a well is screened. Water levels in shallow wells on the valley floor generally are 5-15 feet below land surface and a few feet above water levels in nearby drains. During periods of inadequate surface-water supply and heavy withdrawals for irrigation such as in the mid 1950's, water levels may decline as much as 10-15 feet.

Hydrographs of annual high and low measurements for 10 U.S. Bureau of Reclamation shallow observation wells in the valley are given in Figure 8. Figure 9 shows the location of the

- 13 - 80r

SOURCE OF WATER USE OF WATER

70 -Shallow aquifer Crop irrigation

S Shallow aquifer Municipal and industrial

60 -Medium-depth aquifer Municipal and industrial

Deep aquifer Municipal and industrial

30-

456 5 518

Fiue6 -siae0ihrwl n s f rudW tri h o e eil aly

TeaLnINwMxo 958

Bu 0uo elmto hlo bevto el n eetdGooia uvysalw znemdae n eposrainwlsi h o e eil aly

Hyrgah fosevto el n h ev4-0pd otenpr f h o e eil

0alyso h raetfutain nwtrlvl.Tehdorpsaeesnilyfa o

w lsintes thr prtfth vaeyw reteg udwa risbaks an dve pd zoprtvl ite usata raiaino om ryirgtdcoln ntesuhr ato th walyhsrdcdtea on frcag rmapidsraewtr

Th( yrgah0fsalwwlsi h o erM slaVle ontso n prcal

Figue 6.-timaeWtdawldadUe of Groundatertbe in the Lower Mesilla Valleyadajcn resi apdb

Bour of Rieamtio hallwar tobservaonr wells adrselectdn Gologicledveymn shlowi

Valleyandowere rate stn flututrionso rint lt 90st al0s water-leelsvTh hdrorpsaeesnilyfat. for wells ntsothergneprtfte alywhr h ground-trfwdrtnrm ter ipans rckshad evlpend

- 14 - north to south down the valley. The water- of- table map also shows that the flood plain of the Rio Grande has been an area of ground- 30k- J-90 -1 water discharge and the uplands have been 40 areas of recharge. Leggat and others (1962) 5 estimated the ground-water inflow to the three aquifers of the lower Mesilla Valley to be

30 2JL4-45 60 6 70 7 9 about 18,000 acre-feet per year. The inflow comes from La Mesa to the west, the Franklin Mountains to the east, and from the Mesilla Valley north of Anthony. Figure 7a.-Withdrawals of Ground Water From the Canutillo Well Field and Hydrographs of Before major ground-water development Observation Wells, 1952-80, Shallow Wells in the lower Mesilla Valley (1956), water levels in wells in the deep aquifer were a few feet to as much as 10 feet higher than levels in the shallow aquifer, indicating upward movement of ground water from the deep to the shallow

0 10 aquifer. These conditions still exist in the 8,20 JL4904418 - * 30 southern end of the valley where subsurface * 0 40F 50 flow is constricted by bedrock barriers, and o 6C ~ well development has been inhibited by high salinity in the ground water.

The upward movement of ground water 1952 55 60 65 70 75 1980 has been reversed in the Canutillo well field Figure 7b.-Withdrawals of Ground Water From and along the eastern edge of the valley from the Canutillo Well Field and Hydrographs the town of Anthony south to the community of Observation Wells, 1952-80, Intermediate Wells of Canutillo (Figures 7a, b, c, and 11). This is an area of concentrated withdrawals for municipal and industrial supply which in 1979 totaled about 24,000 acre-feet. These withdrawals, together with an estimated 2,000 acre-feet pumped annually to irrigate cropland above the canals have caused water levels to decline about 10-30 feet in the Anthony-Canutillo area since the early 1950's. Ground water originally flowed laterally and vertically toward the Rio Grande or o 30 o0JL-49-04-419 the valley drains. The water-level declines reversed this original gradient and direction of flow. r ii F, ,l l ,f , rfl,- zoo the static water levels of the jrI~l5LrflHHH ill HMappingthree aquifers in the Canutillo well field is 1952 55 60 65 70 75 I 80 essentially impossible because several of the Figjure 7c.-Withdrawals of Ground Water From wells are operating at any given time. Since all the Canutillo Well Field and Hydrographs of Observation Wells, 1952-80, Deep Wells of the wells normally are shut down only dur-

- 15 - ing periods of emergencies, water-level maps for other thap predevelopment conditions have not been drawn.

On January 26, 1976, a break in the Canutillo main required all of the production wells to be shut down for 53 hours. The recovery of water levels was measured in the three deep observation wells in the field (JL-49-04-41 9, JL-49-04-41 6, and JL-49-04-1 11), and hydrographs of the recovery levels were prepared (Figure 11). A partial and finally a complete shutdown of production wells also occurred during December 1977-February 1978. During early December 1977, only one or two wells were pumped and on December 27, all pumping stopped. Production from the field did not resume until February 21, 1978. Monthly measurements made during the shutdown showed recovery of water levels in the deep observation wells as follows:

(Water levels below land surface, feet)

Well number (altitude, feet) JL-49-04-41 6 JL-49-04-41 9 JL-49-04-1 11 * Date (3,768.5) (3,772.5) (3,775.8)

Dec. 19, 1977 25.97 37.23 45.25

Jan. 20, 1978 18.58 22.13 22.16

Feb. 20, 1978 17.97 21.50 21.15

The recovery measurements made in deep observation wells in the Canutillo field indicate that the artesian head is currently (1 980) about 20 feet below land surface, or about 20 feet below the 1956 predevelopment levels. This decline is comparable to the 10- to 30-foot decline in the water table in the Anthony-Canutillo strip east of the well field and the Rio Grande flood plain and the two may be related. Water Q~uality

Water quality in wells and test holes in the lower Mesilla Valley ranges from very fresh to saline (dissolved-solids concentrations range from less than 300 mg/L to more than 10,000 mg/L). In general, the salinity in ground water increases from north to south, which is also generally true for flow in the Rio Grande and in the valley drains. However, for any particular section across the valley,the quality of water varies both vertically and laterally and may change with time.

Variations in water quality in the shallow wells in the Canutillo field are given in Table 2. The dissolved-solids concentrations in recent samples from 16 shallow production wells ranged from 683 to 1,854 mg/L and averaged 1,019 mg/L. A comparison of these values with those determined in earlier samples shows a general increase in salinity, averaging about 11 mg/L per year.

Table 2 also shows distances between the shallow wells and the lines of recharge in the Rio Grande or Canutillo lateral (Figure 10). Concentrations of dissolved solids in recent samples from six wells located about 0.1 mile west of the river ranged from 766 to 913 mg/L and averaged 853

- 16 - oso

0 -

I- 6 5 5 06 0 518

tios o .1LLLLnd1,83Ig/ i i FebruaryI I 1981.I

Disle-oiscnetaIIons nre nts pesrmnnent mditprd tInwes raned1rom328to04-1mg/Lan I veagJJ4J mg/JLLL .[[[1 HssonnTbe .Th isledsld woc nrtosh v nrae nteitr eitew lsa naeaert faot9m / e yer ot fntal fteicraecnb trbtdt0ekg o neirqaiywtrfo h sh Io- oe( o20fe)it cen htae e ttosalw(0 eto bv)adph

The wae1rm0esxde rdcto el nteCntlofil secpinlylw disso ed-sLid 49-04-701s hw n al . h isovdsoisi sm lscolce

- 17 - during 1980-81 ranged from 252 to 340 mg/L

32000ANTHONY NEW MEXcO and averaged 278 mg/L. No pronounced 1K?.E324JL-49-0- TEXAS changes in water quality have been observed

27S.3E.9. 44' in wells screened in the deep aquifer except -38K for observation well JL-49-04-41 6 (CR-3).

JL-49-04-115 O The sands containing freshwater in the deep JL-49-04-416 ) JL-49f04-4I9 aquifer decrease in thickness north to south. 27S.3E.28.- -4 8 Well CR-3 was screened opposite both fresh 27S.3E.32.1242 o4-4-7 and brackish water zones in the aquifer at a location 0.7 mile south of the nearest deep production well, JL-49-04-402 (city well 201). Periodic jetting of well CR-3 for water samples JL-49- 3-9I6) \L4 0-1 L ( \ \ may have developed the lower part of the screened section opposite sands containing brackish water. The electric log and interval samples collected when the well was drilled EXPLANATION \ L-49- 2 Q\~ indicate the base of the zone containing fresh

9-1-53 26S. 3E. 32.441 WELL NUMBER (NEW MEXICO) water (top of brackish water) is at about 920 JL-49-04-701 WELL NUMBER (TEXAS) \s feet which is about 140 feet above the bottom 37 WELL NUMBER (U.S. BUREAU . OF RECLAMATION), of the screened section. Recent analyses of UNITE}^STATE NEW -E , water from city well 201. have shown an M *IC CHHA increase in dissolved-solids concentration, which may reflect northward migration of the Figure 9.-Location of 15 Water-Level Observation water interface. Wells in the Lower Mesilla Valley With Hydrographs freshwater-brackish Shown in Figures 7a-c and 8

Ground-Water Availability

According to Gates and others (1978, p. 108) about 0.8 million acre-feet of fresh ground water is stored under the Texas partof the lower Mesilla Valley and the adjacent mesa area to the east. About 4.7 million acre-feet is stored under the New Mexico part of the valley and the adjacent mesa area to the west. In addition to the freshwater, about 0.3 million acre-feet of slightly saline water is stored in the Rio Grande alluvium under the Texas part of the valley. These estimates were made using a specific yield of 10 percent for the total thickness of sediments containing fresh or slightly saline water. The volumes estimated to be in storage and theoretically recoverable may be substantially greater than can be practically recovered.

Figure 12 shows the approximate thickness of sediments containing freshwater in the lower Mesilla Valley and adjacent area. The map was prepared by using electric-log and water-sample data from wells and test holes, supplemented by interpretation of electrical-sounding data. The map delineates areas underlain by more than 1,000 feet, 500-1,000 feet, 100-500 feet, and less than 100 feet of freshwater-bearing sediments.

The map shows the thickest section containing fresh ground water, more than 1,000 feet, is in the northwest part of the valley. C. A. Wilson and others (1981, plate 15) show the freshwater section thickening to the north and west in New Mexico to as much as 2,400 feet in the vicinity of the community of Mesquite and the city of Las Cruces. The C. A. Wilson and others study (1981, p.

- 18 - 106' 30

106'37106*37' 3030" 106* 30' Edge of flood plain

00 %)0 S o o \ 'EW__MEXICO__ 32*00' 32*00' -0 ------

Edge of - ( flood plain

Ed of/ Mea-1t0

a Uno

0 \

o Cautilo u a Lop 0

EXPLANAT ION

0 WELL USED FOR CONTROL e z

--- 3750---ATER-LEVEL CONTOUR-- Shows a Ififude -~ 10 at which wafer level would have sfood in lightly cased wells. Dashed where approximately located. Contour interval 5 feet (1.5 meters). National Geodefic Vertical Dafum of 1929

3l*52'30" 31*5 2 ' 30 "

0 I 2 3 4 MILES \ o I I I I Base from U. S. Geological Survey~ topographic quadrangles \ \(7 05

\~STATES\UNITED\ U A-EW !MEXICO j MEXICO CHIHUAHUA 7'30" Sierra de Criofo Rey

Figure 10 Estimated Predevelopment Altitude of the Water Table in the Lower Mesilla Valley s

e s,. - - +' 4+ eagi a . - e a

1- -

1 a * i

alas

e 4- a a s

a 4 JANUARY 1976 26TH 27TH 4-28TH--4-29 TH-+-3OTH NOON NOON NOON NOON

20 w w LL 545 hoursJ z C W30 C.)

C') 0 Z 40 | -J NTRM DEE AQUFER (JL-449-04-Ill) 0 -J w ~ 50 -1I I I I l i I z H ~1. w 0

2 3 4 5 67 89 10 15 20 25 30 ;40 50 60 70 8090 100 TIME, IN HOURS Figure 11.-Recovery of Water Levels in Response to Shutdown of Pumping in the Canutillo Well Field, January 1976

84) estimated that 20 million acre-feet of freshwater and 2.7 million acre-feet of slightly saline water are theoretically available to wells in the upper Mesilla Valley north of the State line at Anthony. On the West Mesa, or La Mesa part of the Mesilla bolson, the study showed 34 million acre-feet of freshwater theoretically available to wells. These estimates were made using specific yields of 9.3 percent in the Mesilla Valley and 9.5 percent on the Mesilla bolson.

HUECO BOLSON-EL PASO VALLEY

The Hueco bolson is the principal aquifer supplying fresh ground water for municipal, military, and industrial supply in the El Paso area. Many geologic and hydrologic studies have been made of the Hueco bolson including those by Sayre and Livingston (1937), Knowles and Kennedy (1958), Alvarez and Buckner (1980), Meyer (1976), and Gates and others (1978). The latter report summarized the availability of fresh and slightly saline ground water in the basins of westernmost Texas including the El Paso area.

The following discussion on the geology and water-bearing characteristics of the Hueco bolson is condensed from the Gates (1978) report with only minor additions or deletions. The

- 21 - Table 2.-Dissolved-Solids Concentrations in Water From Shallow Wells in the City of El Paso Canutillo Welt Field, Lower Mesilla Valley, Texas State Local Slotted Distance to centerline Early analysis Recent analysis Rate of well nurn- interval of Rio Grande (RG) or Dissolved Date Dissolved Date change, in number ber (feet) Canutillo lateral (CL) solids solids dissolved solids (feet) (mg/L) (mg/L) (+ mg/L/year)

Production Wells JL-49-04-403 104 76-155 2,350 CL 583 1952 1,854 1980 +45.4 1,006 1957 +39.9

405 110 53-170 2,180 RG 859 1955 1,675 1980 +32.6 1,269 1957 1,702 1981 +18.0 +22.5 406 103 63-150 450 RG 284 1952 913 1980 935 1955 -.9

407 112 62-200 330 CL 546 1956 817 1980 +11.3 408 111 61-200 210 CL 755 1956 738 1980 -1.5 409 109 37-156 1,400 CL 946 1955 1,324 1980 +15.1 411 108 60-194 1,300 CL 704 1955 1,145 1981 +17.0 972 1957 +6.7

412 102 59-121, 450 RG ~ 455 1952 855 1981 +13.8 140- 160 716 1957 +5.8 413 106 76-155 200 CL 615 1952 881 1979 +9.9 689 1957 +8.7

414 107 62-200 1,100 CL 809 1955 782 1980 -1.1 722 1957 +2.6

415 101 52-62, 460 RG 590 1951 854 1980 +9.1 72-122 683 1957 +7.4 420 105 73-150 330 CL 447 1952 683 1980 +8.4 346 1957 +14.6

423 115 100-200 420 RG 659 1964 890 1979 +15.4 424 116 100-200 460 RG 593 1964 796 1979 +13.5 426 117 100-200 2,350 RG 1,363 1967 1,276 1980 -6.7 428 118 100-200 640 RG 876 1966 810 1980 -4.7 Nonproduction Wells JL-49-04-115 CR-4 102-202 2,560 RG 640 1957 417 CR-i 100-200 1,600 RG 1,520 1966 430 OW#27 20-50 100 RG 1,386 1968 431 OW#28 20-50 110 RG 781 1968 Table 3.-Dissolved-Solids Concentrations in Water From Medium-Depth Wells in the City of El Paso Canutillo Well Field, Lower Mesilla Valley, Texas

Early analysis Recent analysis Rate of State Slotted Dissolved Dissolved change, in well local interval solids solids dissolved solids number number (feet) (mg/I) Date (mg/I) Date ( mg/I/year)

Production Wells

JL-49-04-1 07 301 285-550 345 1957 450 1980 +4.6 426 1981 +3.4

110 309 209-506 614 1967 707 1980 +7.2 664 1981 +3.6

116 308 168-278 274 1969 686 1980 +37.5 741 1981 +38.9

404 305 220-404 294 1969 399 1980 +9.5

410 302 275-444 294 1964 457 1980 +10.2 503 1981 +12.3

421 303 356-550 274 1964 268 1980 -.4 286 1981

495 422 304 198-390 375 1964 1979 +8.0 637 1980 +16

425 307 242-440 308 1964 328 1980 +1.2

427 306 230-461 445 1969 465 1980 +1.8

Nonproduction Well

JL-49-04-41 8 CR-S 355-545 266 1963 349 1979 +S.2 ground-water reservoir known as the Hueco bolson includes areas in Texas, New Mexico, and Mexico. The northern part of the bolson, in Texas and New Mexico, lies between the southern Organ Mountains and the Franklin Mountains on the west and the Hueco Mountains on the east. The southeastern part of the bolson, in Texas and Mexico, lies between several mountain ridges in Mexico on the west and the Diablo Plateau and the Finley, Maline, and Quitman Mountains on the east. Along the Rio Grande, alluvium is entrenched about 200 to 250 feet into the Hueco bolson sediments and locally called the El Paso-Juarez Valley.

The primary water-bearing material of the Hueco bolson and the Rio Grande alluvium is the unconsolidated basin fill (Knowles and Kennedy, 1958, p. 19-20; and Alvarez and Buckner, 1980). In the northern part of the bolson, Davis and Leggat (1967) reported that the thickest section of

- 23 - Ms

4 4

2 di m. & a 4 4

F In 4

4 m P m 4 4 al

4 17'30"' 106*30' 106*3 >t \Edgeflood plain

~~ 5 3 .Anthony 2 960 L~e_ _ 340 I5O 1300,' 460 390. NE W MEX ICO___ 32 00 - - * 40 32 00 A I t TEXAS- 20

Edge ot I 1600 tiood plio 10 1300 H '1700 100 1400 1500 r 935,68 465 - II >1050 ,700 EXPLANAT ION 500 20o II 40 02 >100 22520 210 >260 100 2 600 0 WATER WELL OR TEST HOLE -- Top number indicates 1300 I 1 LaUnion thickness, in feet of basin fill containing freshwater estimated 25 0 k,,01710/ '760 from electrical logs or analyses of water samples in drill- stem tests. Bottom number indicates depth of base of fresh- 560 6 22 water section, in feet. > = "more than "

S900 A ELECTR ICAL-SOU NDING LOCATION AND NUMBER--Numbers 14 and 39 not shown due to poor data. Middle number indicates 25 ,300 50 thickness, in feet of basin fill containing freshwater. Bottom number indicates depth of base of freshwater section, in feet ~400 0

r Cnutillo - --- APPROXIMATE EDGE OF SIGNIFICANT THICKNESS OF

UNCONSOLIDATED BASIN FILL 200 12

-- FAULT-- Approximately located based on resistivity and well 10 38 data. U, upthrown side; D, downthrown side .100 A 260 Q S AREA UNDERLAIN BY 100-500 FEET , OF BASIN FILL-- Containing freshwater - I I ~i"~ 30 446 70 4 LZAREA UNDERLAIN BY 500-1000 FEET OF BASIN FILL-- Containing freshwater MEXIO I6"3 52 5 0 LH AREA UNDERLAIN BY MORE THAN 1000 FEET 50 \ 3 OF BASIN FILL--Containing freshwater \0A 4

|03

1200 1500 Edge o\Ede t tfloodpluin O I 2 3 4 MILES

Bose from U. S. Geological Survey topographic quadrangles

SNEW( MEXICO CHIHUAHUA '' 106*3 7'30"Sierra de Cristo Rey 'e

Figure 12 Estimated Thickness of Sediments Containing Freshwater in the Lower Mesilla Valley t

e 8

a Table 4.-Dissolved-Solids Concentrations in Water From Deep Wells in the City of El Paso Canutillo Well Field, Lower Mesilla Valley, Texas

Recent Early analysis analysis Rate of State Slotted Dissolved Dissolved change, in well local interval solids solids dissolved solids number number (feet) (mg/I) Date (mgi/I) Date ( mg/I/year)

Production Wells

JL-49-04-1 04 203 650-1,150 250 1957 258 1980 +0.3 271 1981

105 204 544-950 260 1959 271 1980 +.5 294 1981

106 202 544-1,090 271 1957 252 1980 -.8 262 1981 -.4

113 206 635-1,200 281 1965 268 1980 -.9 269 1981 -.8

401 205 510-900 265 1958 269 1980 283 1981

402 201 586-1.060 283 1957 302 1980 +.8 340 1981 +2.4

Nonproduction Wells

JL-49-04-1 11 CR-6 768-863, 257 1966 281 1981 +1.6 963-1,063

419 CR-2 585-1,050 269 1966 304 1980 +2.5

416 CR-3 528-1,013 510 1957 1,666 1980 +50 895 1966 +55 basin fill occurs as a trough-shaped body adjacent and parallel to the Franklin Mountains. The total thickness of this section may be as much as 9,000 feet. In the southeastern part of the bolson between El Paso and Clint, the basin fill is from 1,000- to 3,000-feet thick (Davis and Leggat, 1967).

Recharge to the Hueco bolson occurs along the mountains bordering the bolson, and at times locally along the Rio Grande. Before the Rio Grande drained the Hueco bolson, ground water probably flowed to depressions or lakes in the lowest parts of the bolson where it discharged to evapotransporation. After the river cut through the bolson, the floodplain served as the discharge zone. Meyer (1976, p. 18) estimated, from digital-model studies, that the annual recharge around the perimeter of the northern end of the bolson, including areas in New Mexico and around Ciudad Juarez in Mexico, was about 6,000 acre-feet.

- 27 - Large-scale development of ground water in the Hueco bolson started in the early 1900's when deep wells were drilled in the Old Mesa well field to supply residents of El Paso and Fort Bliss (Lippencott, 1921, and Sayre and Livingston, 1945). The Old Mesa field was located in what is now the Fort Bliss sump and the El Paso Water Utilities Mesa plant yard northeast of the intersection of Railroad Drive and Fred Wilson Road which is shown later in Figure 20. The field was first developed in 1904. The production wells were equipped with 8- to 14-inch diameter casing and pumped from a central air-lift plant. The Old Mesa wells were gradually abandoned because of their low operating efficiency and were replaced by large-diameter wells with turbine pumps. The well field produced a total of 68,000 acre-feet through 1926 when it was shut down and the wells were abandoned.

Some of the early large-capacity wells in the Hueco bolson included Fort Bliss No. 1 (JL-49- 13-509) drilled in 1913 at the main base pumping plant, city of El Paso No. 1 (JL-49-13-817) drilled in 1918 near the intersection of Madison (now Radford) and Montana Streets, and Ciudad Juarez No. 1 drilled in 1925 at the corner of Mariscal and Avenida 16 de Septiembre. All of these wells have been abandoned because of failure of casing seals and screens, and deterioration of water quality. The locations of the early wells and selected water-level observation wells are later shown in Figure 16.

Figure 13 includes a bar graph showing the estimated pumpage from the Hueco bolson metropolitan area (hereafter called the metro area), during 1906-80. The area was shown earlier in Figure 4. The Hueco bolson metro area is arbitrarily defined in this report as having large-scale ground-water development and a freshwater section generally exceeding 100 feet in thickness in 1980. The pumpage in the metro area is separated according to use in the United States and Mexico. Prior to the early 1950's, the metro pumpage was less than 30,000 acre-feet per year. Since 1953, the annual withdrawals have increased at an average rate of about 3,600 acre-feet per year and in 1970, totaled 84,982 acre-feet (Table 1). During that year, the city of El Paso (El Paso Water Utilities or EPWU) pumped 39,949 acre-feet from 60 wells and Ciudad Juarez (Junta Municipal de Aquas y Saneamiento or JMAS) pumped 23,985 acre-feet from 23 wells. By 1980, pumpage in the metro area had increased to 129,231 acre-feet; the EPWU pumped 58,213 acre-feet from 81 wells, and the JMAS pumped 55,808 acre-feet from 52 wells.

The cumulative pumpage from the Hueco bolson metro area during 1906-80 totals about 3.0 million acre-feet. About 73 percent of the water (about 2.2 million acre-feet) has been pumped in the United States and about 27 percent (about 0.8 million acre-feet) has been pumped in Ciudad Juarez.

Ground-Water Hydrology

Ground water in the Hueco bolson flows from areas of recharge to points of discharge. The rate of movement is slow, normally less than 1.0 foot per day or a few hundred feet per year, and is controlled by the ability of the aquifer to transmit water (hydraulic conductivity) and the slope (gradient) of the water table.

Figure 14 shows the estimated 1903 and January 1 980 water-level contours in the central part of the Hueco bolson which includes the El Paso, Fort Bliss, and Ciudad Juarez metropolitan areas. The 1903 (predevelopment) contours were drawn from early water-level measurements in

- 28 - -Soo 200 200 -500

180 5-

7 160 N- 400 EXPLA NATION 7 WATER USAGE: 7 140N- UNITED STATES 7 H w D MILITARY INDUSTRIAL, IRRIGATION w Li~ '-a, LAJ C') 0 C-) 120 k- SCIT Y OF EL PASO (EPWU) 300 z 4 4 LL. (I) 0 -7 0 C,) 0 z Q CIUDAD JUAR E Z(JMAS) / H 4 100 H z __ / z 0 7 0 Population /1 H H 7 7 4 z / -J w 80 F- 200 0 7 0~ 4 / a- / a- 60 H- / 7 / 7 ~~0 7 7 7 40k- 7 -100 7 7 7 / 7 7 20 - 7 H / //

/ / / / / / / / / / / / 0 / / / / / / / ~6 -0 1903 IO 20 30 40 50 60 70 1980

Figure 13 Withdrawals of Ground Water From the Hueco Bolson Metro Area, 1906-80, and 10-year Census Population for the City of El Paso &

t. 4 n

u II

32 0730 -__*2_'______*7_3_"____0

~~32u07 30 350 -~ -- Camp

0-0

__ ___mm-ur-----,, -I'

0 .. 3---03

370 NEWME-C

369

070

6 063 0

069 ~

(4 I3 03655 AS

3 5 100 d C

3655~

-- -A- 106 3 6

ZargKz\ . __3__4__ _

3l*3730"

10*22'0 \ eed pQms

EXPLANATION ''* k

0 WELL USED FOR CONTROL\ --- 3700-- WATER-LEVEL CONTOUR, 1903-Shows altitude at which water level would have stood in tightly - cased wells. Contour interval 5 feet National Geodetic Vertical Datum of 1929

-- 3600-- WATER-LEVEL CONTOUR, 1980-Shows altitude 3r*3c - .... . ,~. _f at which water level would have stood in tightly cased wells. Contour interval 10 feet 0 National Geodetic Vertical Datum of 1929

S 2 4 0 10OMW.E

Bae frem U. ., Geoleg cel Surey t1pegrephic quedrengle '

Figure 14 Approximate Altitude of Water Levels in the Hueco Bolson, 1903 and January 1980 4

F wells which were adjusted for the estimated declines prior to the date of measurement, and from steady-state digital model simulations by Meyer (1976).

Prior to, and during the early 1900's ground water in the Hueco bolson flowed south from the Texas-New Mexico line, and east to southeast from the Sierra de Juarez. The general direction of movement was toward the valley of the Rio Grande. There, the water moved.upward through the shallow alluvium and discharged as seepage or through evapotranspiration.

The historical (1906-80) withdrawals of ground water from the Hueco bolson metro area, totalling about 3 million acre-feet, have caused major water-level declines. These declines have significantly changed the direction and rate of flow and in 1980, most of the flow is toward centers of pumping.

Figure 15 shows hydrographs for 13 observation wells in the Texas part of the metro area, and Figure 16 is a map showing locations of the wells. The rates of water-level declines shown on the hydrographs are considered representative of those in the metro area, and range from less than 0.5 foot per year near the eastern boundary to more than 5 feet per year in centers of pumping.

The historical (1903-80) water-level declines can be estimated by subtracting the altitude of the 1980 water levels from the 1903 water levels at any particular location on Figure 14. Accordingly, the greatest declines (deepest cones of depression) of 130 feet are in the downtown areas of El Paso and Ciudad Juarez. The downtown areas have had long-term, large-scale ground-water withdrawals from well fields located near relatively impermeable bedrock boundaries along the Franklin and Juarez Mountain fronts.

The historical declines in the Hueco bolson decrease with distance from the centers of pumping and are minimum, about 10 feet, along the eastern and southeastern boundaries of the metro area. The average 1903-80 decline in water levels over the 223 square miles in the Texas part of the metro area is about 53 feet.

The direction and rate of flow in the shallow alluvial aquifer has also changed significantly since the early 1900's. Figure 17 shows the contours of the water-table altitudes in the shallow aquifer in April 1936, July 1967, and December 1979-January 1980 from downtown El Paso southeast to Ysleta. During 1936, movement of ground water was generally down the valley but also toward wells and irrigation drains. Depths to water were generally a few feet (5 to 10) below land surface. At that time sump pumps were used to drain some of the basements in downtown El Paso.

Water levels in the shallow aquifer declined as much as 20 feet from 1936 to 1967. The declines are attributed to urbanization of the valley, which paved over much of the formerly irrigated fields and drainage areas, and to the increased pumping and declining heads in the underlying bolson deposits inducing downward leakage from the alluvium.

The rates of declines accelerated after the river was lined from downtown El Paso through the Chamizal Zone in 1968. However, part of the increase in the rate of decline can be attributed to a general increase in bolson pumpage in El Paso and a marked increase in Ciudad Juarez. During July 1967 to January 1980, the water levels in shallow wells declined about 20 to 30 feet near the

- 33 - downstream end of the lined section of the river and from 70 feet to more than 80 feet in downtown El Paso. In the downtown area, the water level in an observation well declined from about 25 feet below land surface in September 1968 to 51 feet in December 1971, when it went dry. The water level in a 150-foot deep replacement well drilled in 1975 declined from about 76 feet below land surface in September 1975 to 110 feet in January 1980. In parts of downtown El Paso and probably in Ciudad Juarez, the Rio Grande alluvium has been drained and the shallow water table has declined to the uppermost section of bolson fill.

The January 1980 water-level contours in Figure 17 show that ground water in the shallow aquifer in southeast El Paso is moving northeast away from the river. Movement near the downstream end of the lined section is to the north and west toward centers of pumping from bolson wells. In those areas, the Rio Grande is now a major source of recharge to the shallow aquifer rather than one of discharge.

Digital-model studies of the Hueco bolson indicated that the Rio Grande supplied substantial quantities of seepage to the alluvium since the mid 1930's (Meyer, 1976, Table 1). The average annual seepage to or from the Rio Grande and leakage between the shallow aquifer and bolson fill for 1903-73 estimated in the model studies was as follows:

Average seepage Average leakage (acre-feet per year) between aquifers to/from Rio Grande (acre-feet per year) (+ to river, (+ out of bolson, Period -from river) -into bolson)

1903-20 + 6,864 + 4,677

1920-36 + 353 - 3,423

1936-48 - 4,588 - 7,975

1948-53 - 7,625 -11,780

1953-58 -13,466 -19,698

1958-63 -18,767 -24,609

1963-68 -19,183 -23,549

1968-73 -12,765 -33,278

Water Q~uality

The dissolved-solids concentrations in water from wells in the Hueco bolson metro area are shown in Figure 18, and the average annual change in dissolved solids is shown in Figure 19. Most of the dissolved-solids concentrations used to delineate quality areas shown in Figure 18 were determined from samples collected during 1979-81. Early samples used to calculate rates of

34 - 120 130 140

170

10 250

270

250JLL44--4 -102 280 I I

300 3 5 0 4 0 5 0 57 5 18

JL- 49-22-103

85 225 I -1-I-i -k-4---b---l N4....f.JJL.49.133OIIIIIIII 235 I I JL-49-13-506 j~I iii.,. ii ii 'I

Z ~JL-49-06-50I

JJL-49-06-702

235 365

375

385

395

1940 45 50 55 60 65 70 75 80

Figure 15 Hydrographs of 13 Wells in the Hueco Bolson

- 35 - 4

1 s a 6 *

4 F04062 30' 05 10*'a"& 10 *oC

,20 '30 - - -'.----'.- - . " ------.' - ---_--.--.-_-_-- - -- t--- 32*07'30" Huec

C:01 C mmunity C) ,0 C -A V 32*00' - JL-49-05-205 JL-49-06-102 -- tEXA _____

m JL-49-05-502

JL-49-06-5O1

a ar t~l It"TAN KS

JL-49-O5 -9O5 JL -49 -O6-7O2

30" 4' 0 0 J~L-49-14-102 .'"' o ~~"'~"

"'~'0< z~1

L-49-13-807

JL-49-13-704 o JL-49-13-817 /1

7 ~~-"~" ," ~. "'or on o 80 3 10 Ko o

106' 30

137 30" -4 -

13622' 0" \' flood poi" /n m s.

\ 0t "'A'- 1~0 Edge of 0 ~' flood pla n-X %

EXPLANATION \'

JL-49- 22-103 3 0- _ Ftbeno a LOCATION OF WELL AND NUMBER-- K+*3-'- ~--- With hydrograph shown on Figure 15 JL-49-13-509 Fort Bliss 0 EARLY MILITARY OR MUNICIPAL Water well Nol PRODUCTION WELL--Cited in this \ t report (1

b T'orii

doso from U. 7, 0 oloqicol Sorooy fopognopfie qoodrn I Vt- 100*07 30

Figure 16 Location of 13 Water-Level Observation Wells and 3 Early Municipal and Military Production Wells in the Hueco Bolson %

d 2'30"' l06*22 30'

60* 4H,1

31*15'Od' lI*4A'AA - . . - - 31*45'00" a won

~ rr) 0 ~AW 0 C fr)~ '9, Q 0 fr~ 44%(14~ c EXPLANATION 4/ E XPLA NATION -3640-- WATER-LEVEL CONTOUR, 1980 -- Shows altitude at which water level would have stood in tightly -- 3r704-- WATER-LEVEL CONTOUR, 1936-- Shows altitude at which water level woukd have stood in tightly National Geodetic Ver tica Datum of 1929 cased wells. Contour interval 3 feet National Geodetic Vertical Datum of 1929 I06*22'30' N<\ I06*2~ E----3 SECTION OF RIO GRANDE CONCRETE LINED IN 1968

0 4000 8000 2,000 16,000 F EE T

106*22' 30"

i H 10 Texas/ St.

I ' " 3l*45'00" -~ I 5I43 U 0 0* O / N. 0 C 4/ Q 6>

E XPLANATION

-3660-- WATER- LEVEL CONTOUR, 1967- - Shows altitude at which water level would have stood in tightly cased wells. Contour interval 3 feet F0*~' 30" National Geodetic Vertical Datum of 1929

Figure 17 Approximate Altitude of the Water Levels in the Shallow Aquifer in the Downtown El Paso- Chamizal Area, 1936, 1967, and January 1980 1

a a 4

-il--m.--was -

p 4

p change in dissolved solids (Figure 19) were collected in the 1950's and 1960's in the El Paso-Fort Bliss part of the metro area and during the early 1970's in Ciudad Juarez. With only a few exceptions, the analyses of water from El Paso were by the EPWU laboratory. All analyses in Ciudad Juarez were by the JMAS laboratory. Dissolved-solids concentrations in samples collected from 148 wells in the United States part ranged from about 270 to 1,500 mg/L and averaged 642 mg/L. Dissolved-solids concentrations in recent samples from 45 wells in Ciudad Juarez ranged from about 370 to 1,500 mg/L and averaged 736 mg/L. The annual rate of change in dissolved solids averaged about +10 mg/L per year in the United States and about +30 mg/L per year in Ciudad Juarez.

The dissolved-solids concentrations in samples from wells in the vicinity of the Fort Bliss Tobin well field have decreased slightly in recent years (the well field is shown in Figure 4, and the area of quality improvement, average annual change of -1.6 mg/L per year is outlined in Figure 19). There has been a general and locally pronounced deterioration in water quality in other parts of the metro area.

In parts of downtown El Paso and Juarez, the dissolved-solids concentrations in water from bolson wells have increased at rates of 40 to 100 mg/L per year and this increase is attributed mainly to downward leakage of brackish water from the shallow aquifer and possible upconing of brackish water from below. The downtown area also has the largest declines in water levels in both the bolson and shallow aquifers (Figures 14, 15, and 17). Some of the older wells in the area are screened in both the alluvial and bolson deposits and are existing or potential conduits for vertical (downward) movement of brackish water.

Dissolved-solids concentrations have increased as much as 40 to 60 mg/L per year in wells along Montana Street (U.S. Highway 180-62) near the eastern edge of El Paso. These wells were drilled near the fresh-brackish water interface in the eastern part of the bolson. The increases may reflect intrusion of brackish water from the east or upconing of brackish water from below.

According to Alvarez and Buckner (1980), water in the shallow aquifer in the El Paso Valley within the Hueco bolson metro area ranges from fresh to moderately saline (less than 1,000 to greater than 3,000 mg/L dissolved-solids concentrations). Because of the wide range in dissolved-solids concentrations in the shallow aquifer, leakage of water from the aquifer to the underlying bolson deposits may be beneficial locally, but in other places may be detrimental. Most of the freshwater in the shallow aquifer is stored downstream from the end of the lined section of the Rio Grande and near the river indicating that leakage of freshwater out of the river is recharging the aquifer. Upstream from the downstream end of the section, freshwater generally occurs in the deeper Hueco bolson deposits and slightly saline water occurs in the overlying shallow aquifer.

Old Mesa Well Field

Recent (1979-81) analyses of water from wells along Fred Wilson Road in northeast El Paso show a general increase in dissolved solids and a marked increase in nitrate concentrations above background levels. The data indicate an abnormally high nitrate concentration of 43 mg/L in a sample pumped from El Paso's city well no. 39 (JL-49-1 3-51 1) in July 1980. Samples collected from 10 nearby El Paso Water Utilities (EPWU) and Fort Bliss production wells during 1980-81

- 41 - 4

4 6 - 4 , r p .. a 4

5 a

e- w- 4

a s

a a

M, F e 106 30 06*2 30" 106*15' 106*0730" 106400'

32"07'3O0 .- - -- 3207'30" Hueco ~0 3 Camp

Fort Bliss\

Chaparral L. C Community jO

31*5 '30" ------3l* 52'30"

l06~ 0

--3 ...... V-4 ~ ~3.*4 145 C bd7'

flood plain -~l Q EXPL ANAT ION\

0 WELL USED FOR CONTROL

AREAS OF SIMILAR DISSOLVED-SOLID CONCENTRATION

IilTD <500 milligrams per liter. Very 3i*3 -] - 11111 fresh waler 0

500-1000 milligrams per liter. Freshwater

> 1000 milligrams per liter. Mod- erately saline waler

0 2 4 6 0MLE ZVariable f resh to slightly saline L..-----....L. water B a.o U. S. Gol gcal Sorvey

I p gr phic quago e

10'*07 30"

Figure 18 Areas of Similar Dissolved-Solids Concentrations in Samples From Wells in the Hueco Bolson, 1979-81 t

-11 4

Ulei 0 163 0$*22 30" 0 '15' 10 * 30" 06'00'

3207'30'-- - - ___ -______-- -- ' 3207'30"

Camp C

V EFo EXICK. HEC

0 0 4'

0 0

0 0 0',0 0* 0 2'

o O o ELP0

0 A 0 EL PA,

9 " vY o ,

0 00

106 30

Zorogo 0'\9

-' I -Edeoof N-Ed. .Vge 03

Edgere

E XPL ANATION 1

0 WELL USED FOR CONTROL<

--- 20-- LINE OF EQUAL AVERAGE ANNUAL CHANGE -IN DISSOLVED SOLIDS CONCENTRATION--In - -- Fabn-. milligrams per liter per year. Interval 10 and 313 ~ - ---.-- ---.-- -- 3*' 20 mg/L. ' . _ _ ' '0"

0 2 4 S 09/M LES<

BSo f rom U9, SGologico9 Survy

ttpxgdrh'o"quar.ng,,

0 000'

Figure 19 Average Annual Change in Dissolved-Solids Concentrations in Samples From Wells in the Hueco Bolson Metro Area d

4 m 9

a s'

m. had nitrate concentrations ranging from 6.6 to 17 mg/L. Six samples had nitrate concentrations exceeding the Hueco bolson background level of less than 10 mg/L. Figure 20 shows the locations of the sampled production wells, and Table S shows the cross reference of local and State numbers of wells in the vicinity of the Old Mesa field which was abandoned in 1926. The locations of the Old Mesa wells are shown in Figure 21.

A field investigation was made in 1980-81 to determine the possible sources of the high nitrate concentrations noted above. The investigation centered on the area in and around the EPWU Mesa plant and the Fort Bliss drainage sump (Figure 20). The drainage sump was constructed in the early 1950's and currently (1980-81) collects runoff from about 25 square miles in northeast El Paso and Fort Bliss. The Mesa plant and active city wells 8, 11, and 39 (JL-49-1 3-512, 502, and 511, respectively) are located on a strip of land south of the sump, north of Fred Wilson Road, and near the center of a north-south trending topographic low. This is also the site of the Old Mesa well field (Figure 21).

According to Sayre and Livingston (1945) and historical records, the Old Mesa well field was developed in 1904 by the International Water Company to supply the city of El Paso and Fort Bliss. In 1910 the city of El Paso acquired the property and drilled additional wells. By 1917 a total of 43 wells and test holes had been drilled to depths ranging from 425 to 2,285 feet. The production wells were equipped with 8- to 14-inch-diameter casings and pumped from a central air-lift plant. The Old Mesa wells were gradually abandoned because of their low operating efficiency and replaced by large-diameter wells with turbine-equipped pumps. The well field produced a total of about 68,000 acre-feet through 1926 when production was shut down. Most of the wells were subsequently destroyed by construction of the Fort Bliss sump, a railroad spur, and the widening of Fred Wilson Road. Only nine Old Mesa wells could be located in 1980-81 (see Figure 21).

During the field investigation, four of the nine abandoned Old Mesa- wells, which were located, had shallow ground water seeping into them. Samples of seepage water were collected from these wells by either catching the cascading water or bailing just below the water surface. These included Old Mesa wells 112, 114, 115, and 116 which are also numbered JL-49-1 3-501, 521, 522, and 523, respectively. Samples were also bailed from city wells 12 and 15 (JL-49-1 3- 601 and 605), which were out of production and had the pumps pulled.

Figures 22-25 show the dissolved-solids and nitrate concentrations in water sampled from wells in and near the Old Mesa well field during the investigation. Where accessible, the water levels were measured in wells. The abandoned wells were measured when sampled and the production wells were measured at the end of the pumping season. Figure 26 shows the depths and altitudes of water levels measured in selected wells including levels in abandoned Old Mesa wells JL-49-1 3-501 and 521. The levels in the abandoned wells are perched about 10 to 35 feet higher than the regional ground-water levels. Figures 22 and 24 show the dissolved-solids and total nitrogen as nitrate concentrations in pumped samples. These data are considered to be representative of water currently withdrawn from the major producing zone of the Hueco bolson aquifer within the area of the investigation. Figures 23 and 25 show the same chemical constitu- ents except that all of the samples were bailed from wells.

Figure 27 shows the concentration of dissolved solids as recorded in historic records. In addition to these data, records of the Old Mesa well field stated that wells 81, 96, and 97 (Figure 21) had dissolved-solids concentrations of 292, 335, and 306 mg/L, respectively, in samples collected during the early 1900's. These values and those shown in Figure 27 can be compared with recent data given in Figure 22 to determine the change in dissolved-solids concentrations.

- 47 - EXPLANATION The comparison of total dissolved-solids

0o' LOCATION OF WELL ANO concentration data in Figures 22, 23, and 27, THREE 0101T0 OF STATE E WELL NUBR THE FRST 01 which represent recent aquifer conditions, 68 IIS R LH recent seepage from shallow ground-water formations, and historic aquifer conditions, 24 0' 'AI indicates that the highest concentrations occur in the seepage. These concentrations ranged from 460 to 1,522 mg/L and averaged 849 mg/L. For the recent aquifer samples, the average was about 500 mg/L and the maximum was 693 mg/L. Also a comparison of Figures 22 and 27 shows that 9 of 10 wells had increases. The historic and recent values

0 6 601 averaged 413 and 512 mg/L indicating a gradual deterioration of water quality.

The comparison of total nitrogen as nitrate concentrations in Figures 24 and 25, which represent recent aquifer conditions and recent seepage from shallow ground-water formations, indicates that the seepage con- Figure 20-Locaton of Seecte well centrations of nitrate are considerably higher than the aquifer concentrations. More specifi- cally, the recent aquifer samples ranged from 6.6 to 43 mg/L and the seepage concentrations ranged from 8.4 to 133 mg/L and aver- EXPLANATION aged almost 60 mg/L. The background nitrate Modified from Soyre concentrations in water pumped from bolson 103 MESA WELL NUMBER OLD and Livingston (1945) wells are less than 10 mg/L. o -WELLS FOUND OPEN * WELLS FOUND FILLED o WELLS NOT FOUND The available data indicate that a sub- S WELLS WITH STATE 108 stantial amount of inferior-quality water is NUMBER SHOWN IN 1O7 0 recharged to the Hueco bolson aquifer TABLE 5 being by shallow ground-water seepage into aban- o doned wells in and near the Old Mesa well field. The seepage originates mostly as 81 'O3 impounded urban runoff and possibly by deep percolation of lawn irrigation water which 96 0 113 may be slightly saline. The nitrogen concentrations of water from the aquifer in the Old Mesa well field are above background levels and are assumed to be caused by the seepage mentioned previously. The high nitrogen concentrations in the seepage support this assumption. Unplugged abandoned wells provide a mechanism (conduit) for channeling the inferior-quality recharge water directly 0 1/4 1/2 MILE into the aquifer, and substantial quantities of Figure 21.-Location of Abandoned Wells in the recharge water are available. This well leak- Old Mesa Well Field age could account for most of the increase in

- 48 - total dissolved-solids concentrations. The release of slightly saline water from clay beds caused by a decrease in hydrostatic pressure may also contribute to the increase in dissolved solids in this and other heavily pumped areas in the Hueco bolson.

Table 5.-Cross Reference of State and Local Numbers of Wells in the Vicinity of the Old Mesa Well Field

State well number Owner well number

JL-49-13-204 City well 20

501 Old Mesa well 112

502 City well 11 503 Fort Bliss well 9 504 Fort Bliss well 5

505 Fort Bliss well 6 506 V33 Observation well

511 City well 39

512 City well 8 520 Fort Bliss well 6A

521 Old Mesa well 114 522 Old Mesa well 115

523 Old Mesa well 116

601 City well 12

604 City welll16

605 Old Mesa well 15

606 Fort Bliss well 7

607 City welll19 608 City well 37 624 City well 77

625 City well 16A

626 City well 1SA

- 49 - EXPLANATION 0>*20 EXPLANATION 0 LOCATION OF WELL OCIONE OOWLO-iL 62 ELNUMBERM S693 DISSOLVED SOLIDS--An milligramos per lIter - 11980 EPW)\ milligramst p.> liIer BAILED AMPLE -- InRee DATE SAMPLED. EPWA ls El P be180 Iad strfac aso (1980 EPWU) Woter Utilities; ADDS As Unit d DOATE OAMPLEO. EPWU As El Po TOT ALlOX MILITARY MiLITARY REOERVATiONStesGogiaSrvy jERVAj FORT 8I 'S

204- 11980 EPWU)

0100 5/ 11A0 8 61011011

/1Wi0o >11 / d U66 0 20 1231 610006AIR 11980 E PWUO (1981 EPWU) FORC 80 EW PW) oioli...... 4 2 20 \ /240 11980 EPWU Oil 0 605 11980 EPWU) 0 1300

4 119799EEPWU 11980 EPWU)

TI A/SI950 EPWU) ~ /

58644 06240 520 11WU 4981EWA 4 - (1981USG11981EL EPAAI

E0011A00

NillERNATi~iOAL AIRPORT 7TRAIN /RPR

11980 EPWUI) /

608 111 EPWUI K-'

Do e 1mm T>Gelg.0S eE 1 9 U>0 C5 1aefrmU 0. GOilicAi 081y E PAo 19.5 0 ' Figure 22.-Dissolved-Solids Concentrations in Figure 23.-Dissolved-Solids Concentrations in Samples Pumped From Wells in the Vicinity Samples Bailed From Wells in the Vicinity of the Old Mesa Well Field, 1979-81 of the Old Mesa Well Field, 1980

ERXPLAN AT IAN 011>20' EXPLANATION

0 LOCATION OF WELL

-WELL NUMBER 626 AS NITRATE 1N0 8.5 NITROGEN TOTAL AS NITRATEIND3i 605 NITROGEN TOTAL 3 milliDroms p8r 1i18r 11980 USGSN In milligramos p8r lIter a / 8 In DAMPLE--ln lee> DATE SAMPLED. EPWU Is El Po 3000-MAILED beloo Mob>r Utilities ADDS le AllIed 11980 EPWU) 0>d2urac "DATE SAMPLED. EPWUOi El Pos> Stales GeoIogicoI Surooy TART 0L100 MiARiIl R" " RVAT. FOOT A'LITT MILITARY 000E10' 'iOR NOTE: Bckground voiue for NO3 NOTE B0ckgrond 08108 18r ND3 - 204 oI milligroams per Iiter 17 <.I illigroms per lIte> 1980 ADSI /

6121101E 0ASE 511 FOA CE U A' E \ 198000US1 60 1980 EPWU)O 0 o O 1(1980 EP 60U 11980GUSD5

11980 EPWUO (1980 EPWU) ( 18 SS 1981 EPWMA 11980 EPWU)

7/ 520 11981 EPMWU) 6.6 I / 51 I( 98I EPWUI I~ 11980 EPUIG0 S 60 1291 AODI A 0 '06 .RNATiONs l1(1980 EPW01.

11981 EMAEPWU)

Figure 24.-Total Nitrogen Concentrations in Figure 25.-Total Nitrogen Concentrations in Samples Pumped From Selected Wells in the Samples Bailed From Wells in the Vicinity Vicinity of the Old Mesa Well Field, 1980-81 of the Old Mesa Well Field, 1980

- 50 - EXPLANATION TO) EXPLANATION

/ 1(09- LOCATION11 OF8 WELL88 614 3 -ALT TUDE OF WATER LEVEL oh)' Ti U U 8 2-0 DATE (MONTH-YEAR) / / / TION FOOT VA)s 8001(00 RE TO V"

(940)9 2 / / 7,,, 6 /

364 6 266C 9591 60) S (9351 605 30 (1939)6 0290 3600 (935)1 195

0 (( 460 0624

,2-8 (9371 066 OOB ((9001A

033O ((90(

((1951

( 0 RO

o Geogs Iuw o 95 1G2: Dn r Figure 26.-Water Levels in Selected Wells in Figure 27.-Dissolved-Solids Concentrations in the Vicinity of the Old Mesa Well Field Samples From Wells in the Vicinity of the Old Mesa Well Field-Historic Data

Agricultural Irrigation Project in Northeast El Paso

Starting in the early 1950's, several irrigation farms were established on the mesa part of the Hueco bolson. The farms were all in the area which has been, or soon will be, developed into northeast El Paso. From 1950 through 1975 the farms collectively pumped an estimated 111,000 acre-feet of fresh ground water from bolson wells. Most of the irrigation water was primarily used for growing alfalfa hay on a 622-acre dairy farm (Figure 28).

All of the water pumped at the dairy farm was from wells P-i and P-2 (State numbers JL-49-05-303 and 304). In addition to the well pumpage, the farm used cooling tower effluent for crop irrigation. The effluent was purchased and piped from the El Paso Electric Company's Newman generating plant located 2 miles west-northwest of the farm.

Table 6 shows the quantity and quality of water applied on the dairy farm from 1956 when it was established through 1975 when it was abandoned. During the 20 years of operation, the farm pumped about 99,000 acre-feet of water containing about 926 mg/L average dissolved solids and purchased about 3,000 acre-feet of slightly saline water (2,750 mg/L average dissolved solids).

Figure 28 shows the location of the dairy farm and selected wells in the vicinity of the farm. The well records and much of the water-quality data are also given in the 1980 report by Alvarez and Buckner.

Figure 29 is a graph showing annual rates of irrigation applications on the farm and the weighted average dissolved solids in the water. The annual weighted averages ranged from 775

- 51 - Table 6.-Summary of Quantity and Dissolved-Solids Concentrations in Irrigation Water Applied to a 622-Acre Dairy Farm in Northeast El Paso

Applied water Dissolved solids in applied water (acre-feet) (mg/I) Weighted Year Pumped Purchased Total Pumped Purchased Average

1956 2,148 2,148 775 775

1957 2,455 2,455 844 844

1958 2,455 2,455 855 855

1959 3,253 3,253 868 868

1960 4,511 4,511 878 878

1961 4,511 4,511 888 888

1962 4,809 4,809 900 900

1963 5,304 5,304 913 913

1964 6,281 6,281 923 923

1965 7,390 139 7,329 955 2,750 988

1966 .6,091 250 6,341 885 2,750 959

1967 5,526 315 5,841 1,005 2,750 1,099

1968 4,889 264 5,153 1,180 2,750 1,260

1969 6,445 308 6,753 820 2,750 908

1970 5,831 282 6,113 850 2,750 938

1971 5,819 371 6,190 830 2,750 945

1972 6,755 321 7,076 983 2,750 1,063

1973 6,530 314 6,844 1,050 2,750 1,128

1974 6,591 326 6,917 1,035 2,750 1,116

1975 1,559 206 1,765 1,085 2,750 1,279

Total 99,153 3,096 102,249

Average 926 2,750 976 to 1,279 mg/L. The total annual salt load ranged from about 2,000 tons in 1956 to 10,000 tons in 1974. The total applied salt load for 1956-75 was about 130,000 tons.

Starting in about 1965, the salinity of water pumped from several EPWU wells southwest and downgradient from the farm began to increase. The salinity increase was initially attributed to an invasion (upconing) of saline water into the freshwater zone. The continued degradation of water quality in these and other wells in the vicinity of the farm prompted a cooperative investigation by the El Paso Water Utilities and the Geological Survey in 1974. The data collected during and subsequent to the.1974 investigation identified a spreading plume of ground water containing dissolved-solids concentrations exceeding the background levels in northeast El Paso.

- 52 - 106*22'30"

32,00 [50 32*'G0 1.6 1200 - - .5

-~100 -

,305 e306 4W 1000 - Dissolved solids - NEWMAN GENERA TING -1.2 900 - ELECTRIC COMPANY)I 30 -_304

101 *204 ,301 .30 L _- 31 IRRIGATED I 800 - -1.0 FARM L.. - 700

,601 *608 *602 --. --...- ,401 400 / SOURCE OF WATER 8000 d 304wel -JL-49-0S-303

47000 - Neo on Gon rot ng plant 605 503 ,603 604 -NORTHEAST OXIDATION 6000

WATER UTILITIES)

05000

501 - ,606 607

0 4500

3000 ESXPLAN ATION / 601 * LOCATION OF WELL AND LAST / THEE DIGITS OF SAFT SX DOGS00

JL-49- OR JL-49-06AE 106*22'30"

60 100i956 57 58 59 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 0 3000 6555 FEET

Bos. from GeologicaI Sunoey tOOgraphic ROadrOngI. Figure 29.-Quantity and Dissolved-Solids Concentrations of Irrigation Water of an Abandoned 622-Acre Figure 28.-Location Applied to the Dairy Farm Dairy Farm and Selected Wells in Northeast El Paso

The available hydrologic cdata used for the investigation consisted of chemical analyses of water samples collected from 18 wells, periodic water-level measurements in several wells, and fluid resistivity logs in 3 affected wells. A map showing depths to water and altitude of the water table in 1903 (predevelopment) and January 1980 was prepared for use in defining the thickness of the unsaturated zone (Figure 30). This zone totaled about 310 feet in 1903 and 355 feet in 1980. The direction of flow in the saturated zone was south to southeast in 1980.

Dissolved-solids, chloride, and sulfate concentrations were selected as indicators of the deep percolation of inferior-quality water, and graphs were plotted to show the variations in these indicators with location and time (Figure 31). Maps showing the a real distribution of the dissolved solids in 1966, 1974-76, and 1980 were also drawn in an attempt to delineate the approximate lateral extent of the contamination plume with time (Figures 32a-c).

The salinity (dissolved-solids concentration) maps in Figures 32a and b show the development of a plume of water with higher salinity in the vicinity of the irrigated area from 1966 to the mid 1970's. Figure 32c indicates the plume has dissipated somewhat from the mid 1970's to 1980. The graphs in Figure 31 show that the increased fluctuations were greatest immediately west and southwest of the farm. In many cases there were short-term changes that were somewhat erratic and difficult to explain. The graphs for the more distant wells are reasonably stable; however, they generally show slight increases as do many other wells outside the area of investigation mapped on Figure 31.

The selection of total dissolved solids as an indicator of contamination was not entirely satisfactory because of the presence of saline water beneath and east of the freshwater zone. In

- 53 - an effort to better define the extent of the contamination problem, water samples were collected for nutrient analyses in 1980-81. The concentrations of total nitrogen as nitrate determined in those samples are shown in Figure 33.

The 1980-81 nitrate concentrations ranged from less than 5 mg/L to more than 20 mg/L. The highest concentrations occurred in two samples from well JL-49-05-602 (EPWU production well number 35) located about 0.25 mile southwest and downgradient from the dairy farm (Figures 28, 30, and 33). The nitrate levels of 20.4 and 29.2 mg/L in the 1980-81 samples from well 35 exceeded the background level of less than 10 mg/L by factors of 2 to 3.

During early 1974, the EPWU pulled the pumps from well 35 and two other city production wells, 34 and 56, which are also downgradient from the farm. On February 26, 1974, water samples bailed from various depths in the three wells showed nitrate concentrations as follows:

Well no. Depth sampled Nitrogen (feet below .as NO3 EPWU State land surface) (mg/I) 35 JL-49-05-602 410 30 440 30 570 24 600 28

34 JL-49-05-604 400 31 500 23 800 22

56 JL-49-06-402 370 37 440 26 520 19 560 23

A comparison of the water-quality (chemistry) trends in Figure 31 and the records for applica- tion of inferior quality irrigation water in Figure 29 suggests about an 8-year lag between the beginning of irrigation in 1956 and the first observed deterioration of water quality (increased dissolved solids). A further study of the trends in Figures 29 and 31 suggests that the lag time diminished to about 3 years after the initial aquifer response. The decreased response time may reflect the loss of the earlier water to storage in the unsaturated zone. After the initial buildup of soil moisture, transit time for water to move through the unsaturated zone is expected to be shortened. The data on the maps and graphs are insufficient for accurate determination of the area I extent of the plume or the velocity at which it was spread. The graphs and maps do indicate that most of the inferior water has dispersed in the downgradient direction or has been withdrawn by nearby wells.

The investigation revealed a complex pattern of fluctuations of water chemistry. These fluctuations suggest a plume of inferior-quality water is spreading downgradient from the dairy farm and indicate that deep percolation of irrigation water at the farm may be the principal source of the contaminant. However, the farm cannot be identified as the sole source of the contaminant.

- 54 - 106*22' 30" y M 2 9 6 L

357 3279245{/3746

(/953) 3130 75 E X PL AN AT ION 3373 352 .3735 DEPT H OF WAT ER LEVEL 296 LEVEL 36 7 '33 3 ALTITUDE OF WATER (/964)-MEASUREMENT DATE (EARLY DATA) (/936) '348 3730 ' WELL USED FOR CONTROL 3725 OF WATER LEVEL 3297--DEPTHA L TITUDE OF WATER LEVEL

r (/976) (/954 ,,-- -- 3735 ESTIMATED ALTITUDE OF WATER / LE VE LS IN 190 3-- Co ntour inter val 5 feet

/ 33 - 3730 APPROXIMATE ALTITUDE OF WATER 346 LEVELS IN JANUARY, 1980-- Contour 346 37/3 interval 10 feet 32*00~ - -- 3_5EW 37OSQ MEXICO *(/957)

~3/68769o 05 06 73/6 3766 T3AS 709 (/936) N Power Plan 3 9 3679 5) 3/

43480 :. H DIYFR NORTHEAST OXIDATION PONDS U' 37/26st"3 3 I267 I3706

3693 309 0 I 2 3 4 MILES 360 3642 364 U 36 3699

3705

4 ___ 36~ e 6

3627340 3275 4 77

S245 263' 290 343 (/954) g 36 62 3636536272723663 062 3695

106"22' 30" Figure 30.-Depths to Water and Approximate Water-Table Elevations for Early Data and January 1980, in Northeast El Paso and Adjacent Areas in New Mexico

Several factors complicate the identification of its origin. One source could be the continued leaching of salts historically deposited in the soils but flushed down by the excess irrigation water. This could be supported by the data showing that the salinity of some of the well-water samples was higher than the original irrigation water, even though these well-water samples were a composite from over 300 feet of screened aquifer. Furthermore, the volume of water that is available for deep percolation (applied less evaporation, crop consumption, and runoff) is considerably reduced from the applied volume, of which about 95 percent was pumped from two on-site wells. However, the salinity of leachate would be expected to be somewhat higher than the applied water because of evaporation.

Another possible source of inferior-quality water in northeast El Paso is the EPWU's northeast sewage oxidation ponds located 1 .5 to 3 miles southeast of the dairy farm (Figure 28). During 1963 through 1979, inflow to the ponds totaled about 74,600 acre-feet and in 1979 was about 5,900 acre-feet. Percolation from the ponds has been estimated at 2.9 million gallons per day (3,250 acre-feet per year) based on water-budget studies (Environmental Impact Statement, draft "Wastewater treatment facilities, northeast El Paso, Texas,'' February 1980). The configuration of the water table in the vicinity of the ponds in 1980 (Figure 30) shows that a mound about 5 feet high has developed, and this mounding may reflect deep percolation of impounded sewage.

55 - 4'

= &

4 &

4 4 A P

e 9

b a a

b -1 i'l a

i A

s ,nnn gag - 1000 r . . . 4600 JL-49-0005-JL39-0730 66 64 200 - -. 66 96 -75 64 6 00 - 0 8 3 10 - 61 - 0 16000 0. JO 2 00 - 610666it68r y 66 3 2 4 600 - .14 _6 L4-535 66- -0 d L49.-01oi 0600- 2 1400 JL-49-05-304 T0t61 disso6 6e *.-6 i1r8t. 661id6 40 . Tot6I dissol4d s691ds -25 . 000 - 0. 200 - ~ ~ -50 0. 400 - 6 9400 - 46 9 0800

0~( I 200 - .200 - Choie Sla 1000 --- 50 .1 T w 71 72 7374 75 76 7778 79 960 0 --- ' - . ~j j 440 -25 8 800 7-2-45.. - 6669 70 717273 74 7376 777 0 2 116 66 67 6869 70 7172 730 8 --i6--i 1-- - I S3 061Nitrate 87576769.4200 2 00 -

Tot l disso111d ss 57 sa se so si 62 as 34 as as 87 as se 70 7172 73 74 Ts 73 77 Ta 79 eso 10602 2301 00 - - - - 0 4 32*00 0 657-0-5 6l l 6263 6 6546 6l6-69.. 7 7 7' 097 65 00 -

0- 200 - 3.1. - 4/ 0 1000 l l l I l l l lI 50 1400 , , , , , , , , 70 46100 -9-6-2 061d681 7071727 7 7 707 80'18 9 -soids - 22 1200 - 1400 .70' o2 -- 20m o -- 50 0

440 - -~ 00 4 6 4 0 -o hOrid0 40 4 800 - 068- 6. -"-666 1800 0 IRR IGAT E D O - -64 11000 - - S3-- 200o DA IRY 00.1- 94 .63 -56 73 97077 37 7 -77 79 9140 08 60 - L-49-05-312 - ______FA R .4 6 600 -6ois- 6- -i -753 u. 6 200 1400 -4-0 600 - 8 4 1200 691146d - 0 5859 60 6162 63 64 65 66 67 68 69 70 7 72 73 74 75 78 77 7n 7a an nila 44 .1 3 19oo 47 7 79 6975727 .1000 - 508

6600 - -6.0. 25 0 50 360 - JL-49-05-60 00 - -31 -86 - -256 44w 400 -- 04 2004 061-6-6 3 0 1000 - *6109686 6 6, 600 - 1-4 -0 - 0 !-66 67 66970 7172 73744175. 40 -- 0 .134 200 So ft604.

00 800 - .~ L-4.,,....------195 59 60 6162 6364 6566676869 70 77273 74 7576777 79 9. 600 -- - 02 20 3 0

6 66 6 4 6 .l 9.i20 4 6 6 8 9 7 r 7273 777 9 0I1626 646566 67 6869 70 7 72 7374 7376 7778796490 l06*2~ 1000 .

. JL-49-05-604 . 50 1000 664600 - JL-4 -05-6 -25 666 JL-49-05-501 6 JL-49-05-607 2 6 . 061Nir 06t91 66 00 964 00

- JL-i49-0-603 02 d1di68 o46 id6 -2 6 - 660 406 -25 6 00- 3 40 .13400 -6 6. 600 KLLNIWr.LJ. - .1 44 04666461666064 65666766697671 73 7378757677 76l'~ r 68 - LEWUu 83400 lor 00.1 440200

5. 200 ChOrid6 *6 0 04 0 35758 59 60 6 7** ** 7 7 7 4 Ta74 74 77 7" 'o. - Sulf66 6 I691960 61 62 63 64 65 66 67 68 69 70 71 72 7374 75 76 778 09 19E4 -

E X PL A NAT ION

0 6000 2,000 18,000 FEET * GROUND-WAT ER DATA COLLECTION SITE Bose from U S Geological Survey topographic quadrangle Figure 31 Variations in Dissolved-Solids, Chloride, and Sulfate Concentrations in Water From Wells in the Vicinity of the Dairy Farm, 1957-80 g

a a a

6 .1 a.. IO6*22 30" 106*22'30" S2*00' . . 3D*UO 32*OO 32*OO / / / / / / / / 'I / 340 / 500 I --- 1 100 / .1. NEWMAN GENERATING NE)WMAN GENERATING 0 PLANT PASO c - (EL 1200 P1 LANT (EL PASO 700 1000 ELECTRIC COMPANY) El ELECTRIC COMPANY) *- -

.530 490 t -E 400 *410 400' IRRIGATED\ RIGIATED 00 1600 DAIRY ~ FARM "1

490 ,430 400 960 v~5" /1 V /1 / / / / / a, I rt' 380, 310 *470 *32O 090. e690 ,SOO *750 NORTHEAST OSIDATION PONDS EL PASO PONDS (EL PASO WATER UTILITIES) WATER UTILITIES

370, ,490 330* e540

EX PLAN AT ION / EX PLAN AT ION

400 WELL USED FOR CONTROL -- Number 400 SWEL L USED FOR CONTROL-- Number 106*22 30" indicates dissoved-solids carvenrato, 06*22'3D" ir millig ramsa per liter irdicates dissalved-solids cancert ra tion, nr milligrams per liter --400- LINE OF EQUAL DISSOLVED-SOLIDS CONCENTRATION, 1966 -- Interval 200miIligrams per liter -- 400- LINE OF EQUAL DISSOLVED-SOLIDS CONCENTRATION, Dashed here approximate U 3000 NODOFEET - 1974-76-- Interval 000 milligrams per liter U 3USD 6000 FEET Sashed here approximate

Bas, trem Geloial Svay - ees, r Gelegicel Ovrvey tepegaphic adranal. - toreaehe qaedreala Figure 32a.-Approximate Areal Distribution of the Figure 32b.-Approximate Areal Distribution of the Dissolved-Solids Concentration in Water From Wells Dissolved-Solids Concentration in Water From in the Vicinity of the Dairy Farm, 1966 Wells in the Vicinity of the Dairy Farm, 1974-76

1D6*22 SD" I06*22'30" 3DD' I 32 0nn'

.380\ / _~~ / -a NEWMAN GENER,ATING 0 NEWMAN GENERATING PLANT (EL PA) Cv I800 -a- NT (EL PASO 12.411980) TRIC ELECTRI COMP ANY) -- -a- ELEC COMPANY) ?----

500 380 650 NP 5.8(119601 *7.1(39D) I IRRGAUT ED L / 4.9 (19R1) 6.6 119811 IR RIGATEDD~ -DAIRY / 10.2119811)- DAIRY FARM L FARM 1

550 1150 600 600 ~~s" 11.1 (19R0) 00.4 11980 10.2011961) (19R1) /1 09.2

(rt' 7.11(1980) 700 *480 , 450 400 e4.41(1981) 8.0 (1980) NORTHEAST OXIDATION NORTHEAST OXIDATION PONDS (EL PASO PONDS (EL PASO 600 WATER UTILITIES) WATER UTILITIES)

490 30 a 4.4 11981) 4.41(1960) 8.91981)

EXPLANATION

400* WE L LUSED FORCONTROL - -Nvmber EXPL AN.ATION indicates dissolved-solids carcertration, 1U"*22'30" in milligrams per liter 0.4* WELL USED FOR CONTROL -- Nvmber 119801 indicates nitrate concentrationain milligrams pen liter.(year sampled shown in --400--- LINE OF EQUA L DISSOLVED-SOLIDS CONCENTRiATION, pareentheasis) (06*22'030" (980-- Interval 2OOmilligrams per liter Dashed cher approximate U 3000 6000FEET

eas. tree Geoloal Soreyt ease tree Gelogical Saracey teopgraphic auadrangl. tepagraphic qadreale

Figure 32c.-Approximate Areal Distribution of the Figure 33.-Concentrations of Nitrate in Water From Dissolved-Solids Concentration in Water From Wells inthe Vicinity of the Dairy Farm, 1980 and 1981 Wells in the Vicinity of the Dairy Farm, 1980

59 - In 1982, construction started on a tertiary treatment plant at the north-east oxidation ponds. The plant is part of the Hueco bolson recharge project (HBRP), which will treat sewage to drinking water standards and recycle the water via injection wells (Environmental Impact Statement draft "Wastewater treatment facilities, northeast El Paso, Texas," February 1980; Garza and others, 1980). The project is planned to include a 10 million gallons per day (11,000 acre-feet per year) advanced waste treatment plant with a pipeline system to 10 injection wells. The injection wells will be spaced at distances from pumping wells so that there will be a minimum of 2 years residence time in the bolson prior to production. The existing oxidation ponds will be abandoned upon completion of the treatment plant and injection facilities.

Ground-Water Availability

The most important aspect of the ground-water resources of the El Paso area is the amount of freshwater stored in the Hueco bolson, the principal aquifer, and specif ically the amount of water which could be withdrawn without incurring a serious overdraft. The overdraft could create an unacceptable reduction in well yields, deterioration of water quality beyond accepted standards, and possible land-surface subsidence.

Figure 34 shows the 1970-80 withdrawals of ground water in the United States (Texas) and Republic of Mexico (Ciudad Juarez) parts of the Hueco bolson metro area. The figure also shows recent projections of future pumping rates by various Federal, State, and local agencies. These projections, based primarily on anticipated population growth and per capita water consumption, extend to the years 2020 or 2030 and are all subject to revision.

During the current investigation, the chemistry data for wells in the Hueco bolson were compiled and plotted to define areas having similar levels of dissolved-solids concentrations (Figure 18) and areas of significant changes in dissolved solids (Figure 19). These data and the altitudes of the water table in January 1980 (Figure 14), the top of the freshwater in the El Paso Valley, and the base of the freshwater in 1973 (Figure 35) were used to estimate the approximate volume of sediments containing freshwater in the Texas part of the Hueco bolson metro area in January 1980.

Figure 36 shows the approximate thickness of sediments containing water with dissolved- solids concentrations less than 1,500 mg/L. The mapped area, which is restricted to the Texas part of the Hueco bolson metro area, is underlain by an estimated 54.2 million acre-feet of sediments with fresh to slightly saline water. Most of the sediments, about 29.0 million acre-feet, contain water with dissolved-solids concentrations ranging from 500 to 1,000 mg/L. About 24.6 mill ion acre-feet of sediments contain water with less than 500 mg/L dissolved-solids concentrations, and approximately 0.6 million acre-feet of sediments contain water with 1,000 to 1,500 mg/L dissolved solids.

Digital-model studies (Meyer, 1976) indicate a value of 0.1856 for specific yield as a reasona- ble approximation for the saturated section of the Hueco bolson. Using this value, the volumes of theoretically recoverable resources in 1980 would yield 4.57 mill ion acre-feet of very fresh water (dissolved-solids concentrations less than 500 mg/L), about 5.38 million acre-feet of freshwater (500 to 1,000 mg/L dissolved-solids concentrations), and about 0.11 million acre-feet of slightly saline water (1,000 to 1,500 mg/L dissolved solids). The freshwater resources would total about 10.0 million acre-feet.

60 - 3 50 I In addition to the estimated 10.0 million EXPLANATION acre-feet of freshwater reserves, there is an PUMPAGE PROJECTIONS: estimated 4 million acre-feet of slightly saline TQO--TXARDEPRRMENT OF~- water (1,000 to 3,000 mg/L dissolved-solids KNOWLES AND ALVAREZ, 1979 p -o-- EL PASO WATER UTILITIES- / concentrations) stored within and outside the Texas part - -US.GEOLOGICAL SURVEY-- / of the Hueco bolson metro area. V 50 ~~ MEYER, 1976 -- I- Part of the slightly saline water PUMPAGE DATA: may be -i.--. U.S. GEOLOGICAL SURVEY-- - ~ blended with freshwater to accepted quality - For 1970-80. Data shown- 0 - n Tabl I 4 standards and used for municipal and indus- 2010 -- ~ 0 trial supply. 0

4 C,) 0 Table 7 shows recent estimates of - fresh- H - z water in storage in the Texas part of the metro

4 / - area starting in 1903 and projecting to the year 2030. The projected volumes in storage IC 7-- are theoretically recoverable and were com- puted using an average specific yield of 0.1856 calculated by Meyer (1976) and the projected rates of pumping shown in Figure 34. All of the projections were made prior to the initiation of the Hueco bolson recharge 1970 1980 1990 2000 2010 2020 2030 project. A scheduled three-dimensional Figure 34.-Recorded and Projected WitIhdrawals solute transport model study of the bolson will of Ground Water From the Hueco Bolson incorporate the conservation aspects of the Metro Area, 1970-2030 recharge project. This study will also update the recent projections of future rates of ground-water withdrawals as shown in Figure 34 and the volumes of water remaining in storage as shown in Table 7.

RIO GRANDE

The quantity of flow and concentrations of dissolved solids in the Rio Grande at El Paso for 1943-80 is shown in.Table 8. The annual discharge for that period averaged about 317,000 acre-feet. The maximum and minimum flows were 631,800 acre-feet in 1943 and 57,481 acre-feet in 1956. Concentrations of dissolved solids in monthly samples ranged from 427 mg/L in August 1957 to 3,832 mg/L in November 1957. For the 34-year period 1943-76, the dissolved solids in monthly samples averaged 1,142 mg/L, and for the same period the discharge-weighted dissolved solids concentration averaged 819 mg/L. Drain flow returns and sewage outfalls contribute most of the low flow in the river, which accounts for the wide seasonal range in dissolved-solids concentrations. In general the dissolved-solids concentrations are highest during periods of low flow and are lowest during periods of high flow.

. SUMMARY AND CONCLUSIONS

Located in the far western tip of Texas, the El Paso area includes most of El Paso County, some adjacent areas in New Mexico, and Ciudad Juarez in Mexico. The economy of the area is

61 - Table 7.-Estimates and Projections of Freshwater in Storage in the Texas Portion of the Hueco Bolson, 1903-2030 (million acre-feet)

Texas Water Knowles Meyer Development Hickerson and Alvarez~ Current Year (1976) Board (1977) (1979)1 (1979) investigation

1903 11.45 --

1973 10.64 - 10.6-

1980 ---- 10.0

1990 9.8 -9.1 9.6-

2020 7.4 -4.4 5.6

2030 - 2.73 2.1 3.7-

1Esiatsmade discounting recharge of mostly slightly to moderately saline water from shallow aquifer. NOTE: Proposed recycling of tertiary treated sewage unaccounted in all projections. dependent upon the use of ground water for municipal, industrial, and military supply, augmented by diversions of flow from the Rio Grande for crop irrigation and limited municipal supply.

In the El Paso area, significant pumping of ground water began in the early 1900's. Develop- ment gradually increased to the early 1950's, when it accelerated accompanying rapid population growth. In 1980, pumpage for municipal, industrial, and military supply totaled 164,354 acre- feet. Most of the water, 132,652 acre-feet, came from the Hueco bolson. The Mesilla bolson and Rio Grande alluvium supplied 27,461 and 4,241 acre-feet. These three aquifers are interstate and international in extent.

Pumpage from the Mesilla bolson and Rio Grande alluvium in the lower Mesilla Valley averaged about 31,000 acre-feet per year in 1979-80. Most of the water, 21,000 to 22,000 acre-feet, came from wells in the El Paso Water Utilities Canutillo Field. In 1980, shallow wells pumped 578 acre-feet, medium-depth wells 10,290 acre-feet, and deep wells 10,049 acre-feet. Water levels in shallow wells are generally 5 to 15 feet below land surface and may decline as much as 10 to 15 feet during years of heavy pumping. Water levels in medium-depth wells are normally a few feet below the levels in shallow wells. Water levels in deep wells, which reflect changes in artesian pressure in the deep aquifer, range from- 20 to 100 feet below land surface and have declined about 20 feet since the mid-i1950's.

The quality of water from shallow wells in the Canutillo field ranges from fresh to slightly saline. Most of the freshwater (dissolved-solids concentrations of less than 1,000 mg/L) is pumped from wells near the Rio Grande and Canutillo lateral which are line sources of recharge. Dissolved-solids concentrations in water from medium-depth wells range from 328 to 741 mng/L. Increases in dissolved solids in these wells are attributed to interformational leakage and insuffi-

62 - Table 8.-Summary of Flow and Concentrations of Dissolved Solids in the Rio Grande at El Paso, 1 943-8O1

Dissolved solids Flow in the Rio Grande (mg/I) (acre-feet) Range of Average of Discharge- El Paso Delivered Year monthly samples monthly samples weighted average station to Mexico

1943 669-1,221 ' 862 750 631,800 61,309 1944 677-1,250 903 787 611,900 61,798 1945 669-1,324 889 802 568,900 60,684

1946 713-1,236 914 816 497,900 60,466 1947 669-1,294 -981 824 458,860 58,012 1948 691-1,324 968 838 431,680 60,689 1949 655-1,221 870 750 463,540 60,256 1950 669-1,294 916 772 472,630 60,602

1951 809-1,375 1,072 '905 252,000 33,059 1952 530-1,530 1,032 736 283,680 49,890 1953 655-1,537 1,000 743 264,500 37,760 1954 684-2,229 1,249 .956 93,725 10,147 1955 802-2,839 1,502 1,015 67,089 8,185

1956 993-3,200 1,905 1,052 57,481 7,864 1957 427-3,832 1,858 596 139,571 23,290 1958 655-3,251 1,267 721 392,863 60,050 1959 610-1,750 1,130 831 385,810 60,110 1960 669-1,706 1,154 860 378,260 60,320

1961 713-1,670 1,119 867 300,690 48,610 1962 677-1,618 1,044 802 376,116 60,057 1963 713-1,655 1,174 875 263,711 39,693 1964 809-2,640 1,522 1,059 64,307 6,653 1965 434-2,273 1,341 566 202,392 36,658

1966 552-2,111 1,117 691 308,782 49,618 1967 655-1,743 1,131 816 232,744 29,829 1968 728-1,670 1,155 890 264,408 39,677 1969 61 0-1,831 1,100 780 365,407 59,884 1970 684-1,618 1,070 824 360,719 60,065

1971 684-1,677 1,116 824 244,156 34,847 1 97r2 691-2,162 1,328 905 133,568 15,515 1973 588-2,118 1,181 831 301,789 60,000 1974 588-1,699 1,014 750 382,953 60,050 1975 728-1,559 1,025 846 360,959 60,052

1976 588-1,530 943 780 402,835 60,172 1977 691-2,008 1,206 214,553 24,824 1978 521-2,560 1,373 156,024 14,903 1979 432-2,260 1,059 312,594 60,055 1980 531 -1,710 985 353,983 60,033 1Data from International Boundary and Water Commission annual bulletins (1943-80). cient depth of screen setting. Dissolved-solids concentrations in water from deep production wells range from 252 to 340 mg/L. One deep observation well showed a significant increase in dissolved solids attributed to excessive depth of screen setting and a progressive development of brackish water from deep sand zones in the southern part of the field.

Natural (boundary) recharge to the aquifers in the lower Mesilla Valley has been estimated at 18,000 acre-feet per year. About 0.8 million acre-feet of freshwater and 0.3 million acre-feet of slightly saline water are in storage in the Texas part of the valley.

- 63 - E

a e

e 1

4 m

ea a

a e h 4 de F

a 6 0 6 - #- 4 . 4.

% 93', 106430 106*2 30" 106-15' 106*07 30" 106000

32"73"- ______...- -.- , ..- ____-- .- -- 2*07'30"

Huec&

FtBliss

Chaparral L C Commurnty C

TEA - 33 20

ForIBli 1434n'IUEC

TAN 3443

Z3 r

$ ------0S337 '3 0 S i"3 7 3 0 " - - - -- .

lot

Edge of \- Edge of C06"2230' \ Io li mesa

Edtgeo '1

flood eaie-t, \

EXPLANAT ION\

-30- -WATER-LEVEL CONTOUR--Shows altitude of ___3______base at freshwater. Contour interval 100 feet. -3__ 3P330 ___ National Geodetic Vertical Datum of 1929. 161

Torn3

! \%

0 2 4 6 8 IO MILES \

N>O p Base from Ii, S. Geological Sarvey -3 topographic quadrangles

106*0 f434 43 43

Figure 35 Approximate Altitude of the Base of Freshwater in the H ueco Bolson, 1973

II s y n i 4 e4

a a a F

mmm.==. A

e g 1 4

e' 4

m 106030 10 *22 30" 10 5' 0 *0 30" 0600

Camp

Foor 0U$ HUsG

TANKS

300

z> Juore 0

- Ys ta ~ ~ Hor zo

06*30

Edg of Edg of 100*22 30"odp ms

Edge of flood ploia sn

EXPL ANAT ION

-- 20-LINE OF EQUAL THICKNESS OF FRESHWATER-- 3130 - -__ __

Interval 100 feet.

0 2 4 0 If O1 MLES N

Ifose from U. S, Geologicol Sorsey foporaphio quodrengles

106400

Figure 36 Estimated Thickness of Sediments Containing Freshwater in the Hueco Bolson, January 1980 P 1

4 Irrigation of cropland in the lower Mesilla valley and El Paso-Juarez Valley is mainly from diversion of flow in the Rio Grande supplemented by pumping wells. Consequently, the amount of ground water pumped varies inversely with surface-water availability. There was a full 3-foot surface-water allotment in 1980, and irrigation pumping was minimal during that year.

In 1980, pumpage in the El Paso-Fort Bliss-Ciudad Juarez metro part of the Hueco bolson totaled 129,231 acre-feet. Most of the water, about 114,000 acre-feet, was for municipal supply, with 58,213 acre-feet used in El Paso and 55,808 acre-feet used in Ciudad Juarez. The 1906-80 pumpage in the metro area totals about 3.0 million acre-feet, with 2.2 million acre-feet pumped in the United States and 0.8 million acre-feet pumped in Mexico.

Withdrawals of ground water during 1906-80 caused water levels in bolson wells to decline about 130 feet in the downtown sections of El Paso and Ciudad Juarez. In that area, rates of decline currently exceed 5 feet per year and are approaching 10 feet per year. The historical declines diminish away from centers of pumping and are less than 10 feet along the eastern and southern boundaries of the metro area.

Water from most wells in the Hueco bolson metro area contains less than 1,000 mg/L dissolved solids. Dissolved solids in recent samples from 148 wells in and near El Paso and Fort Bliss averaged 642 mg/L, and samples from 45 wells in Ciudad Juarez averaged 736 mg/L. Dissolved solids are increasing at an average rate of about 10 mg/L per year in the United States part and about 30 mg/L per year in Mexico. Most of the deterioration in water quality is attributed to downward leakage of brackish water from the shallow alluvial aquifer and to deep percolation of applied lawn and crop irrigation water. Abandoned wells act as local conduits for vertical leakage between layers in the aquifers.

.Excluding interformational leakage, recharge to the Hueco bolson has been estimated at about 5,640 acre-feet per year. In 1980 an estimated 10.0 million acre-feet of freshwater was in storage in the Texas part of the metro area. About 4.6 million acre-feet contained dissolved-solids concentrations of less than 500 mg/L and 5.4 million acre-feet contained dissolved-solids concentrations of 500 to 1,000 mg/L.

A significant volume of slightly saline water, as much as 4 million acre-feet, is in recoverable storage in the Texas part of the Hueco bolson. Part of this water may be available for blending with freshwater to provide for municipal-industrial supply. The planned recycling of tertiary-treated sewage could also extend the life of the Hueco bolson, the principal aquifer.

During 1943-80, flow in the Rio Grande at El Paso ranged from 57,481 acre-feet to 631,800 acre-feet and averaged about 317,000 acre-feet per year. Dissolved-solids concentrations in monthly samples of flow during 1943-80 ranged from 427 to 3,832 mg/L. For the 34-year period 1943-76, dissolved-solids concentrations in monthly samples averaged 1,142 mg/L, and the discharge-weighted values averaged 819 mg/L.

The numerous studies which have been made on the ground-water resources in the El Paso area have reasonably defined the volume of freshwater in storage. The ratio of the volume in storage to the rate of annual withdrawals is small compared to most of the major population centers in the southwest and this ratio is decreasing at a significant rate because of the area's increasing population growth and water demand.

- 69 - BIBLIOGRAPHY

Alvarez, H. J., and Buckner, A. W., 1980, Ground-water development in the El Paso region, Texas, with emphasis on the resources of the lower El Paso Valley: Texas Department of Water Resources Report 246, 346 p.

Audsley, G. L., 1959, Records of wells and results of exploratory drilling in the El Paso Valley and Hueco Bolson southeast of El Paso, Texas: U.S. Geological Survey open-file report, 147 p.

Ball, D. M., 1974, Ground-water model for the Mesilla Valley for 1960 through 1973: New Mexico State University, Las Cruces, New Mexico, Master of Science thesis, Civil Engineering, 120 p.

Barrie, J. F., 1975, A gravimetric study of south-central New Mexico and West Texas: University of Texas at El Paso, Master of Science thesis, Department of Geology.

Bluntzer, R. L., 1975, Selected water well and ground-water chemical analysis data, Ciudad Juarez, Chihuahua, Mexico: Texas Water Development Board file report, 29 p.

Borton, Robert L., 1980, Bibliography of ground-water studies in New Mexico, 1848-1979, A supplement to Bibliography of ground-water studies in New Mexico, 1873-1977: New Mexico State Engineer, Santa Fe, New Mexico, Special Publication.

Broadhurst, W. L., Sundstrom, R.W., and Weaver, D. E., 1949, Public water supplies in western Texas: Texas Board of Water Engineers duplicated report, 284 p.

1951, Public water supplies in western Texas: U.S. Geological Survey Water-Supply Paper 1106, 168 p.

C.I.E.P.S., S. C., Engineers, Consultants and Planners, 1970, Study of the technical, economic, social, and financial feasibility of the rehabilitation of the irrigation district, Juarez Valley, Chihuahua (Mexico); translated by the Ralph McElroy Company, Inc., Austin, Texas; edited by Gunnar Brune, Texas Water Development Board, and Sergio Garza, U.S. Geological Survey, Austin, Texas: Secretaria de Recursos Hidraulicos, Mexico City, D. F., Mexico, v. I, II, and Ill.

Cliett, T. E., 1969, Ground-water occurrence of the El Paso area and its related geology: New Mexico Geological Society, Border Region, Chihuahua Mexico and United States, Guidebook 20th Field Conference, 1969, p. 209-214.

Conover, C. 5., 1954, Ground-water conditions in the Rincon and Mesilla Valleys and adjacent areas in New Mexico: U.S. Geological Survey Water-Supply Paper 1230, 200 p.

Cooper, J. B., 1962, Note on post-Rustler Red Beds of Permian age of southeast New Mexico and west Texas, in Geological Survey Research, 1962, Short papers in geology, hydrology, and topography: U.S. Geological Survey Professional Paper 450-B, p. 24-26.

Davis, M. E., 1965, Development of ground water in the El Paso District, Texas, 1960-63, Progress report No. 9: Texas Water Commission Bulletin 6514, 34 p.

- 70 - Davis, M. E., 1967, Memorandum on availability of water having less than 2,500 parts per million dissolved solids in the alluvium of Rio Grande near El Paso, Texas: U.S. Geological Survey open-file report, 7 p.

Davis, M. E., and Leggat, E. R., 1965, Reconnaissance investigation of the ground-water resources of the Rio Grande basin, Texas, in Reconnaissance investigations of the ground- water resources of the Rio Grande basin, Texas (1 )the upper basin: Texas Water Commission Bulletin 6502 p. Ul1-U99.

1967, Preliminary results of the investigation of the saline-water resources in the Hueco bolson near El Paso, Texas: U.S. Geological Survey open-file report, 27 p.

Day, J. C., 1978, International aquifer management: The Hueco bolson on the Rio Grande River: Natural Resources Journal, v. 18, no. 1, p. 163-180.

Fahnestock, R. K., and Maddock, Thomas, Jr., 1964, Preliminary report on bed forms and flow phenomena in the Rio Grande near El Paso, Texas, in Geological Survey Research 1964: U.S. Geological Survey Professional Paper 501-B, p. Bi140-B 142.

Follett, C. R., 1954, Records of water-level measurements in El Paso County, Texas: Texas Board of Water Engineers Bulletin 5417, 50 p.

Garza, Sergio, Weeks, E. P., and White, D. E., 1980, Appraisal of potential for injection-well recharge of the Hueco bolson with treated sewage effluent-Preliminary study of the northeast El Paso area, Texas: U.S. Geological Survey open-file report 80-1106, 37 p.

Gates, J. S., White, D. E., Stanley, W. D., and Ackermann, H. D., 1978, Availability of fresh and slightly saline ground water in basins of westernmost Texas: U.S. Geological Survey open- file report 78-663, 115 p., also published as Texas Department of Water Resources Report 256.

Gates, J. S., and Stanley, W. D., 1976, Hydrogeologic interpretation of geophysical data from the southeastern Hueco bolson, El Paso and Hudspeth Counties, Texas: U.S. Geological Survey Open-File Report 76-650, 37 p.

Gaume, A. N., 1977, A monthly average water quality model of the Rio Grande: New Mexico State University, Las Cruces, New Mexico, Master of Science thesis, Civil Engineering, 186 p.

Geo Fimex S. A., 1970, Valle de Juarez-Chihuahua, estudio geofisico: Geofisica Mexicana, S. A., Report 1713, 16 p.

Harbour, R. L., 1972, Ground water, in Geology of the northern Franklin Mountains, Texas and New Mexico: U.S. Geological Survey Bulletin 1298, p. 83.

Herrick, E. H., and Davis, L. V., 1965, Availability of ground water in Tularosa basin and adjoining areas, New Mexico and Texas: U.S. Geological Survey Hydrologic Investigations Atlas HA-i191.

- 71 - Hickerson, J. T., 1978, Water requirements and available resources for El Paso, Texas: Unpub- lished memorandum report prepared for the El Paso Public Service 'Board, by the El Paso Water Utilities, 14 p.

Howard, C. S., and Love, S. K., 1945, Quality of surface waters of the United States, 1943, with a summary of analyses of streams in Colorado River, Pecos River, and Rio Grande basins, 1925 to 1943: U.S. Geological Survey Water-Supply Paper 970, 180 p.

International Boundary and Water Commission, United States and Mexico, 1943-80, Flow of the Rio Grande and related data; or Flow of the Rio Grande and tributary contributions: Water Bulletins Nos. 13-50.

King, W. E., Hawley, J. W., Taylor, A. M., and Wilson, R. P., 1969, Hydrogeology of the Rio Grande Valley and adjacent intermontane areas of southern New Mexico: New Mexico Water Resources Research Institute Report No. 6, New Mexico State University, Las Cruces, New Mexico, 141 p.

1971, Geology and ground-water resources of central and western Dona Ana County, New Mexico: New Mexico Water Resources Research Institute, in cooperation with New Mexico State Bureau of Mines and Mineral Resources, Hydrologic Report 1.

King, P. B., King, R. E., and Knight, J. B., 1945, Geology of Hueco Mountains, El Paso and Hudspeth Counties, Texas: U.S. Geological Survey Oil and Gas Investigations map 36.

Knowles, D. B., and Kennedy, R. A., 1956, Ground-water resources of the Hueco Bolson, northeast of El Paso, Texas: Texas Board of Water Engineers Bulletin 5615, 265 p.; republished 1958, U.S. Geological Survey Water-Supply Paper 1426, 186 p.

Knowles, T. R., and Alvarez, J. H., 1979, Simulated effects of ground-water pumping in portions of the Hueco bolson in Texas and Mexico during the period 1973 through 2029: Texas Depart- ment of Water Resources LP-1 04, 26 p.

Lansford, R. R., Ben-David, S., Roach, F., Creel, B. J., and Beattie, B. R., 1977, Regional water management with full consumptive use: New Mexico Water Resources Research Institute, Las Cruces, Technical Report 88.

Lee Wilson and Associates, Inc., 1981, Water supply alternatives for El Paso: Unpublished consultant's report prepared for the El Paso Water Utilities Public Service Board, 75 p.

Leggat, E. R., 1 957a, Memorandum on the water-supply wells at Biggs Air Force Base, El Paso, Texas: U.S. Geological Survey open-file report, 8 p.

______1 957b, Memorandum on ground-water conditions and suggestions for test drilling in the Logan Heights area, El Paso, Texas: U.S. Geological Survey open-file report, 12 p.

1962, Development of ground water in the El Paso district, Texas, 1955-60, progress report No. 8: Texas Water Commission Bulletin 6204, 65 p.

72 - Leggat, E. R., and Davis, M. E., 1 967a, Results of ground-water study in Chamizal settlement area, El Paso, Texas-Ciudad Juarez, Mexico: U.S. Geological Survey administrative report, 25 p.

______1 967b, Use of wells to lower the water table along relocated channel of Rio Grande in the El Paso, Texas-Ci udad Juarez, Mexico area: U.S. Geological Survey administrative report, 6 p.

Leggat, E. R., Lowry, M. E., and Hood, J. W., 1962, Ground-water resources of the lower Mesilla Valley, Texas and New Mexico: Texas Water Commission Bulletin 6203, 195 p.; republished 1963, U.S. Geological Survey Water-Supply Paper 1 669-AA, p. AA1 -AA49.

Lippincott, J. B., 1921, Memorandum reports on El Paso water system: Unpublished consultant's reports for the City Water Board, El Paso, as cited in U.S. Geological Survey Water-Supply Paper 919, by A. N. Sayre.

Livingston, Penn, and Birdsall, J. M., 1944, Progress report on the ground-water supply of the El Paso area, Texas: U.S. Geological Survey open-file report, 16 p.

Mattick, R. E., 1967, A seismic and gravity profile across the Hueco bolson, Texas: Geological Survey Research 1967, Professional Paper 575-D, p. D85-D91.

Meyer, W. R., 1976, Digital model for simulated effects of ground-water pumping in the Hueco bolson, El Paso area, Texas, New Mexico, and Mexico: U.S. Geological Survey Water Resour- ces Investigations Report 58-75, 31 p.

Meyer, W. R., and Gordon, J. D., 1972, Development of ground water in the El Paso district, Texas, 1963-70: Texas Water Development Board Report 153, 50 p.

1973, Water-budget studies of lower Mesilla Valley and El Paso Valley, El Paso County, Texas: U.S. Geological Survey open-file report, 43 p.

Muller, D. A., and Price, R. D., 1979, Ground-water availability in Texas, estimates and projections through 2030: Texas Department of Water Resources Report 238, 77 p.

Murphy, E. C., and others, 1906, Flood on Rio Grande, New Mexico-Texas, in Destructive floods in the United States in 1905 with a discussion on flood discharge and frequency and an index to flood literature: U.S. Geological Survey Water-Supply Paper 162, p. 34-38.

Myers, R. G., and Pinckley, K. M., 1981, Bibliography of dissertations and theses on water and water related topics from New Mexico State University, through December 1980: New Mexico Water Resources Research Institute Report No. 138, New Mexico State University, Las Cruces, New Mexico.

Nye, S. 5., 1930, Pumping test of well at site of proposed Federal Detention Prison about one mile south of La Tuna, for Bureau of Prisons, Department of Justice: U.S. Geological Survey open-file report, 11 p.

- 73 - Rapp, J. R., 1957, Summary of test drilling and ground-water conditions in the McGregor Range area, Otero and Dona Ana Counties, New Mexico, and El Paso County, Texas: Unpublished report by the U.S. Geological Survey for the U.S. Army Corps of Engineers, 83 p.

Richardson, G. B., 1909, El Paso, Texas,folio: U.S. Geological Survey Geologic Atlas of the United States No. 166, 11 p.

Sayre, A. N., 1938, Estimating safe yield as illustrated by the El Paso, Texas ground-water investigation: Economic Geology, v. XXXIII, no. 7, p. 697-708.

1940, The ground-water supplies of the El Paso area, Texas: U.S. Geological Survey memorandum, 4 p.

Sayre, A. N., and Livingston, Penn, 1937, The ground-water resources of the El Paso, Texas, area: U.S. Geological Survey open-file report, S p.

1940, Memorandum regarding the El Paso water supply: U.S. Geological Survey open-file, 15 p.

1945, Ground-water resources of the El Paso area, Texas: U.S. Geological Survey Water-Supply Paper 919, 190 p.

Scalapino, R. A., and Irelan, Burdge, 1949, Ground-water resources of the El Paso area, Texas, progress report no. 6: Texas 8oard of Water Engineers duplicated rept., 25 p.

SI ichter, C. J., 1905, Observations on the ground waters of the Rio Grande Valley: U.S. Geological Suvey Water-Supply Paper 141, 83 p.

Smith, R. E., 1956, Ground-water resources of the El Paso district, Texas, Progress Report No. 7: Texas Board of Water Engineers Bulletin 5603, 36 p

Song, Ming-Sun, 1975, Characterizing irrigation return flows of selected drains in the Mesilla Valley: New Mexico State University, Las Cruces, New Mexico, Master of Science thesis, Civil Engineering, 93 p.

Sundstrom, R. W., 1945, Memorandum on ground-water resources of the El Paso, Texas, area, progress report: U.S. Geological Survey open-file report, 12 p

1952, Ground water for irrigation at the Federal Correctional Institution, La Tuna, Texas: U.S. Geological Survey open-file report, 12 p.

Sundstrom, R. W., and Hood, J. W., 1952, Results of artificial recharge of the ground-water reservoir at El Paso, Texas: Texas Board of Water Engineers Bulletin 5206, 19 p.

Taylor, A. M., 1967, Geohydrologic investigations in the Mesilla Valley, New Mexico: New Mexico State University, Las Cruces, New Mexico, Master of Science thesis, Civil Engineering, 130 p.

- 74 - Texas Department of Water Resources, 1981, Inventories of irrigation in Texas, 1958, 1964, 1969, 1974, and 1979: Texas Department of Water Resources Report 263, 295 p.

Thomas, H. E., and others, 1963, Effects of drought in the Rio Grande basin: U.S. Geological Survey Professional Paper 372-D, p. Dl1-D59.

U.S. Bureau of Reclamation, 1973, Water resources of El Paso County, Texas: Unpublished report prepared by the Rio Grande Project, New Mexico-Texas Project Office, El Paso, Texas, for the Texas Water Development Board, Austin, Texas.

U.S. Environmental Protection Agency, 1980, Draft environmental impact statement, wastewater treatment facilities, northeast El Paso, Texas.

U.S. Geological Survey, 1970, Saline ground-water resources of the Tularosa basin, New Mexico: Research and Development Progress Report 561, 128 p.

U.S. Water and Power Resources Service, 1980, Elephant Butte Reservoir-Fort Quitman Project, New Mexico-Texas (Rio Grande Environmental Project): Special report and Summary of special report.

West, S. W., and Broadhurst, W. L., 1975, Summary appraisals of the Nation's ground-water resources-Rio Grande region: U.S. Geological Survey Professional Paper 81 3-D, 39 p.

Wilson, C. A., White, R. R., Orr, B. R., and Roybal, R. G., 1981, Water Resources of the Rincon and Mesilla Valleys and adjacent areas, New Mexico: New Mexico State Engineer Technical Report 43, 514 p.

Zohdy, A. A. R., 1969, The use of Schlumberger and equatorial soundings in ground-water investigations near El Paso, Texas: Geophysics, v. XXXIV, no. 5, October 1969.

Zohdy, A. A. R., Bisdorf, R. J., and Gates, J. 5., 1976, Schlumberger soundings in the lower Mesilla Valley of the Rio Grande, Texas and New Mexico: U.S. Geological Survey open-file report 76-324, 77 p.

- 75 - p

6 =

4 1 1 e

s 4

4 e t

% # 4

i e a e

a p

P p 9