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Research about New Mexico

Source-linked reports with geographic coverage including New Mexico.

At least 469 records · Page 26Linked to original sources
USGS1996

Concentrations and loads of selected trace elements and other constituents in the Rio Grande in the vicinity of Albuquerque, New Mexico, 1994

The Pueblo of Isleta and the New Mexico Environment Department have established water-quality standards for the Rio Grande, which flows through Albuquerque, New Mexico. Trace-element concentrations historically have been greater than maximum permissible concentrations allowed by these standards. It is not known if these concentrations are due to sources from the Albuquerque metropolitan area or are from natural or other sources outside Albuquerque. Accurate water-quality data with lower reporting limits than have been previously available were collected, and instantaneous concentrations and loads were calculated for trace elements and other constituents in the Rio Grande during high-flow and low- flow conditions. Seven sampling sites were selected upstream from, in, and downstream from metropolitan Albuquerque. Concurrent streamflow measurements were made at the time of sampling to determine suspended-sediment loads. Samples were analyzed separately for trace elements dissolved in water (less than 0.4 micrometer in diameter) and for those contained in suspended sediment (greater than 0.1 micrometer in diameter). Sample collection and processing, analytical methods, and quality control are discussed.

New Mexico↗
USGS1996

Water resources data, New Mexico, water year 1995

Water-resources data for the 1995 water year for New Mexico consist of records of discharge and water quality of streams; stage, contents, and water quality of lakes and reservoirs; and water levels and water quality in wells and springs. This report contains discharge records for 194 gaging stations; stage and contents for 26 lakes and reservoirs; water quality for 53 gaging stations and 112 wells; and water levels at 128 observation wells. Also included are 106 crest-stage partial-record stations. Additional water data were collected at various sites not involved in the systematic data collection program, and are published as miscellaneous measurements. These data represent that part of the National Water Data System collected by the U.S. Geological Survey and cooperating State and Federal agencies in New Mexico.

New Mexico↗
USGS1996

Water-quality assessment of the Rio Grande Valley, Colorado, New Mexico, and Texas: Occurrence and distribution of selected pesticides and nutrients at selected surface-water sites in the Mesilla Valley, 1994-95

The Rio Grande Valley study unit of the U.S. Geological Survey National Water-Quality Assessment Program conducted a two-phase synoptic study of the occurrence and distribution of pesticides and nutrients in the surface water of the Mesilla Valley, New Mexico and Texas. Phase one, conducted in April-May 1994 during the high-flow irrigation season, consisted of a 6-week time- series sampling event during which 17 water-column samples were collected at 3 main-stem sites on the Rio Grande and a synoptic irrigation-run sampling event during which 19 water-column samples were collected at 7 main-stem sites, 10 drain sites, and 2 sites at the discharges of wastewater-treatment plants. Three samples are included in both the time-series and irrigation-run events. Phase two, conducted in January 1995 during the low-flow non-irrigation season, consisted of a non-irrigation synoptic sampling event during which 18 water-column samples were collected at seven main-stem sites, nine drain sites, and two sites at the discharges of wastewater-treatment plants and a bed- material sampling event during which 6 bed-material samples were collected at six sites near the mouths of drains that discharge to the Rio Grande. The 51 water-column samples were analyzed for 78 pesticides and metabolites and 8 nutrients along with other constituents. The six bed-material samples were analyzed for 21 pesticides and metabolites, gross polychlorinated biphenyls, and gross polychlorinated naphthalenes. The presence of dissolved pesticides in the surface water of the Mesilla Valley is erratic. A total of 100 detections of 17 different pesticides were detected in 44 of the water-column samples. As many as 38 percent of these detections may be attributed to pesticide use upstream from the valley or to nonagricultural pesticide use within the valley. There were 29 detections of 10 different pesticides in 17 samples during the irrigation run and 41 detections of 13 pesticides in 16 samples during the non-irrigation run. Nine pesticides were detected during both phases of the study. The most commonly detected pesticides in the water-column samples were DCPA, which was detected in 29 samples, and metolachlor, which was detected in 17 of the samples. DCPA was detected throughout the Mesilla Valley, whereas metolachlor was detected mainly in the northern and central parts of the valley. The maximum pesticide concentration found during the study was 0.75 microgram per liter of carbofuran, which was detected at the East Side Drain site during the irrigation run. No water-column pesticide concentration exceeded U.S. Environmental Protection Agency's drinking-water standards or any applicable Federal or State criteria or guidelines. A total of 21 occurrences of six pesticides and metabolites were found in the bed-material samples. Chlordane, diazinon, and methyl parathion were detected once each, whereas DDD, DDE, and DDT were detected at all six bed-material sites. Water-column samples for the analysis of nutrient concentrations were collected at all sampling sites during both phases of the study. The concentrations of each nutrient ranged from at or below the individual minimum reporting level to as much as two or three orders of magnitude larger than the minimum reporting level. The concentration of each nutrient was left skewed with most of the values toward the lower end of the range. The larger concentrations of each nutrient, except dissolved nitrite plus nitrate, were associated with wastewater-treatment- plant sites 4 and 16. The larger concentrations of dissolved nitrite plus nitrate were generally associated with the non- irrigation run; however, the largest concentration was at site 4 during the irrigation run. During this study, the Mesilla Valley as a unit was a source of nutrients to the Rio Grande. Wi

New Mexico↗
USGS1996

Reconnaissance investigation of water quality, bottom sediment, and biota associated with irrigation drainage in the Vermejo Project area and the Maxwell National Wildlife Refuge, Colfax County, northeastern New Mexico, 1993

Based on findings of limited studies during 1989-92, a reconnaissance investigation was conducted in 1993 to assess the effects of the Vermejo Irrigation Project on water quality in the area of the project, including the Maxwell National Wildlife Refuge. This project was part of a U.S. Department of the Interior National Irrigation Water-Quality Program to determine whether irrigation drainage has caused or has the potential to cause significant harmful effects on human health, fish, and wildlife and whether irrigation drainage may adversely affect the suitability of water for other beneficial uses. For this study, samples of water, sediment, and biota were collected from 16 sites in and around the Vermejo Irrigation Project prior to, during the latter part of, and after the 1993 irrigation season (April, August-September, and November, respectively). No inorganic constituents exceeded U.S. Environmental Protection Agency drinking-water standards. The State of New Mexico standard of 750 micrograms per liter for boron in irrigation water was exceeded at three sites (five samples), though none exceeded the livestock water standard of 5,000 micrograms per liter. Selenium concentrations exceeded the State of New Mexico chronic standard of 2 micrograms per liter for wildlife and fisheries water in at least eight samples from five sites. Bottom-sediment samples were collected and analyzed for trace elements and compared to concentrations of trace elements in soils of the Western United States. Concentrations of three trace elements at eight sites exceeded the upper values of the expected 95-percent ranges for Western U.S. soils. These included molybdenum at one site, selenium at seven sites, and uranium at four sites. Cadmium and copper concentrations exceeded the National Contaminant Biomonitoring Program 85th percentile in fish from six sites. Average concentrations of selenium in adult brine flies (33.7 μ g/g dry weight) were elevated above concentrations in other invertebrates. Concentrations of other elements were below their respective toxicity levels. Plants, invertebrates, fish, and fish fillets were collected and analyzed. These analyses were compared to diagnostic criteria and to each other to determine the extent of bioaccumulation of trace elements. Plants contained larger dry weight concentrations of aluminum, arsenic, boron, chromium, iron, lead, magnesium, manganese, nickel, and vanadium than invertebrates and fish. Adult brine flies, gathered from playas, contained larger geometric mean dry weight concentrations of boron, magnesium, and selenium than other invertebrates. Of all samples collected, the largest mercury concentrations were found in fish fillets, although these concentrations were below levels of concern. Mercury and selenium bioaccumulation was evident in various habitats of the study area. Biological samples from Natural playa, an endemic wetland, and Half playa, a playa that receives additional water through seepage and irrigation delivery canals, generally had elevated concentrations of boron, iron, magnesium, and selenium than samples from reservoir and river sites. Selenium concentrations were lowest in biota from the two reservoir sites, although a wetland immediately downstream from the dam impounding Lake No. 13 (created by seepage from the reservoir) had elevated concentrations of selenium in biota. The geometric mean selenium concentration of whole-fish samples, except those from Lakes No. 13 and No. 14, exceeded the 5- μ g/g dry weight selenium concentration that demarcates the approximate lower limit of the threshold range of concentrations that have freen associated with adverse effects on piscine reproduction. Biota collected on and in the area around Maxwell National Wildlife Refuge contained concentrations of selenium that are in the lower range of threshold values that have been associated (dietarily) with risks of avian reproductive abnormalities. Bottom-sediment samples from two sites downstream from the irrigation project were collected and analyzed for 23 organic compounds (principally organochlorine pesticide residues). Three compounds were detected at the two sites: DDD was found at 0.2 microgram per kilogram, DDE was detected at 0.1 microgram per kilogram at both sites, and chlordane was detected at 1 microgram per kilogram. None of the 28 whole-fish and fillet samples analyzed for PCB and organochlorine pesticide residues contained any of the 23 organic compounds tested for at concentrations higher than the analytical reporting limit (less than 0.01 μ g/g wet weight). Concentrations of inorganic analytes were generally within established guidelines or expected concentrations for water, sediment, and biota. lirigation-return flows were found to be unrelated to adverse effects in biota.

New Mexico↗
USGS1996

Runoff and erosion on the Pajarito Plateau: Observations from the field

Sites within the Pajarito Plateau have widespread, if low levels, of surface contamination. The major mechanism by which contaminants are moved and redistributed is surface runoff and associated soil erosion. To better understand the processes involved, we have been making detailed measurements of water and sediment movement at three sites across the plateau, one located in a ponderosa pine forest, one in a stable pinyon-juniper woodland, and one in a rapidly eroding pinyon-juniper woodland. For the ponderosa pine site, both surface runoff (overland flow) and subsurface runoff (interflow) are important. Overland flow can be generated by intense summer rain storms, more gentle frontal storms, or snowmelt while soils are frozen; interflow, although generated mostly by melting snow, can occur any time of the year. For the pinyon-juniper sites, the most important producer of runoff is summer thunderstorms, but at all scales snowmelt runoff can be important as well. The rapidly eroding pinyon juniper site produces more runoff than the stable pinyon-juniper site and hundreds of times more erosion than either the stable pinyon-juniper or the ponderosa site. These long-term studies are providing a better conceptual understanding of runoff and erosion on the Pajarito Plateau and other similar semiarid regions and enabling better assessments of the potential for contaminant transport in these systems.

New Mexico↗
USGS1995

Comparison of hydrothermal alteration of carboniferous carbonate and siliclastic rocks in the Valles caldera with outcrops from the Socorro caldera, New Mexico

Continental Scientific Drilling Program (CSDP) drill hole VC-2B [total depth 1761.7 m (5780 ft); maximum temperature 295 °C] was continuously cored through the Sulphur Springs hydrothermal system in the western ring-fracture zone of the 1.14 Ma Valles caldera. Among other units, the hole penetrated 760.2 m (2494.1 ft) of Paleozoic carbonate and siliciclastic strata underlying caldera fill and precaldera volcanic and epiclastic rocks. Comparison of the VC-2B Paleozoic rocks with corresponding lithologies within and around the 32.1 Ma Socorro caldera, 192 km ( 119 miles) to the south-southwest, provides insight into the variability of alteration responses to similar caldera-related hydrothermal regimes. The Pennsylvanian Madera Limestone and Sandia Formation from VC-2B preserve many of the sedimentological and diagenetic features observed in these units on a regional basis and where unaffected by high temperatures or hydrothermal activity. Micrites in these formations in VC-2B are generally altered and mineralized only where fractured or brecciated, that is, where hydrothermal solutions could invade carbonate rocks which were otherwise essentially impermeable. Alteration intensity (and correspondingly inferred paleopermeability) is only slightly higher in carbonate packstones and grainstones, low to intermediate in siltstones and claystones, and high in poorly cemented sandstones. Hydrothermal fracture-filling phases in these rocks comprise sericite (and phengite), chlorite, allanite, apatite, an unidentified zeolite and sphene in various combinations, locally with sphalerite, galena, pyrite and chalcopyrite. Terrigenous feldspars and clays are commonly altered to chlorite and seriate, and euhedral anhydrite “porphyroblasts” with minor chlorite occur in Sandia Formation siltstone. Fossils are typically unaltered, but the walls of some colonial bryozoans in the Madera Limestone are altered to the assemblage chlorite-sericite-epidote-allanite. La, Ce and Nd are present in an unidentified hydrothermal mineral occurring throughout much of the VC-2B Pennsylvanian sequence. Carboniferous carbonate and siliciclastic formations within and around the Socorro caldera show a similar style of alteration and mineralization to their Valles caldera counterparts, but by contrast locally host commercial, caldera-related, base-metal sulfide deposits. As in the Valles rocks, mineralization and alteration in those of the Socorro caldera were strongly controlled by porosity. Unless disrupted by fractures, breccias, or karst cavities ( not identified in Valles caldera drill holes), the rocks remained relatively unaltered. Where these features allowed ingress of mineralizing hydrothermal solutions, base-metal sulfides and rare-earth-element-bearing minerals were precipitated.

New Mexico↗
USGS1995

Mineral and energy resources of the Roswell Resource Area, East-Central New Mexico

The sedimentary formations of the Roswell Resource Area have significant mineral and energy resources. Some of the pre-Pennsylvanian sequences in the Northwestern Shelf of the Permian Basin are oil and gas reservoirs, and Pennsylvanian rocks in Tucumcari Basin are reservoirs of oil and gas as well as source rocks for oil and gas in Triassic rocks. Pre-Permian rocks also contain minor deposits of uranium and vanadium, limestone, and gases. Hydrocarbon reservoirs in Permian rocks include associated gases such as carbon dioxide, helium, and nitrogen. Permian rocks are mineralized adjacent to the Lincoln County porphyry belt, and include deposits of copper, uranium, manganese, iron, polymetallic veins, and Mississippi-Valley-type lead-zinc. Industrial minerals in Permian rocks include fluorite, barite, potash, halite, polyhalite, gypsum, anhydrite, sulfur, limestone, dolomite, brine deposits (iodine and bromine), aggregate (sand), and dimension stone. Doubly terminated quartz crystals, called 'Pecos diamonds' and collected as mineral specimens, occur in Permian rocks along the Pecos River. Mesozoic sedimentary rocks are hosts for copper, uranium, and small quantities of gold-silver-tellurium veins, as well as significant deposits of oil and gas, carbon dioxide, asphalt, coal, and dimension stone. Mesozoic rocks contain limited amounts of limestone, gypsum, petrified wood, and clay. Tertiary rocks host ore deposits commonly associated with intrusive rocks, including platinum-group elements, iron skarns, manganese, uranium and vanadium, molybdenum, polymetallic vein deposits, gold-silver-tellurium veins, and thorium-rare-earth veins. Museum-quality quartz crystals are associated with Tertiary intrusive rocks. Industrial minerals in Tertiary rocks include fluorite, vein- and bedded-barite, caliche, limestone, and aggregate. Tertiary and Quaternary sediments host important placer deposits of gold and titanium, and occurrences of silver and uranium. Important industrial commodities include caliche, limestone and dolomite, and aggregate. Quaternary basalt contains sub-ore-grade uranium, scoria, and clay deposits.

New Mexico↗
USGS1995

Geology and mineral and energy resources, Roswell Resource Area, New Mexico; an interactive computer presentation

This Compact Disc-Read Only Memory (CD-ROM) contains a program illustrating the geology and mineral and energy resources of the Roswell Resource Area, an administrative unit of the U.S. Bureau of Land Management in east-central New Mexico. The program enables the user to access information on the geology, geochemistry, geophysics, mining history, metallic and industrial mineral commodities, hydrocarbons, and assessments of the area. The program was created with the display software, SuperCard, version 1.5, by Aldus. The program will run only on a Macintosh personal computer. This CD-ROM was produced in accordance with Macintosh HFS standards. The program was developed on a Macintosh II-series computer with system 7.0.1. The program is a compiled, executable form that is nonproprietary and does not require the presence of the SuperCard software.

New Mexico↗
USGS1995

Description of geophysical-log data base for boreholes and wells in and adjacent to the Albuquerque Basin, New Mexico

Digital geophysical logs for boreholes and wells in and adjacent to the Albuquerque Basin area have been entered into a data base established by the New Mexico District of the U.S. Geological Survey and documented as of September 1994. The logs were digitized from paper or mylar copies or were collected as digital data during the logging of boreholes and wells. The location of these boreholes and wells with digital geophysical logs is shown in a map. The 1,020 logs and the types of logs for the 186 sites are listed in a table.

New Mexico↗
USGS1995

Structure of the basins and ranges, Southwest New Mexico, an interpretation of seismic velocity sections

This report presents a geologic appraisal of seismic velocity sections that profile a total of 790 km in southwest New Mexico west of Las Cruces and south of Lordsburg and Deming. The present work outlines the contribution of these velocity sections to estimating areas favorable for mineral resource occurrences. Seismic refraction surveys are carried out with the initial goal of estimating the subsurface distribution of acoustic compressional velocity (Vp), which may ultimately be interpreted to provide information on lithology, geologic structure, and the occurrence of natural resources. The seismic sections presented here show velocity detail having dimensions of 100's to 1000's of meters to a depth of about 2.5 km, and across a net of traverses that profile most basins well as several ranges in the study area. Figure 1 shows the location of the seismic refraction lines. The lines are designated 1, 2, 3, 4, 5, and 7; there is no line 6. The survey covers a broad swath of the southwest Basin and Range Province extending from the Arizona border eastward to the Rio Grande River, and from the Mexican border to about lat. 32° 30' N. Lines 1, 3, and 7 traverse the axis of basins in roughly northsouth directions; the remaining lines 2, 4, and 5 trend east-west and cross various ranges and basins. Seismic data that have been collected in this region include deep-crustal refraction traverses by university scientists and commercial seismic reflection profiles acquired for petroleum exploration. Results of deep-crustal refraction studies are reviewed to provide a regional setting for the higher resolution refraction data. Results from seismic reflection will not be discussed. Industry reflection data in the area are not generally available for non-proprietary use. The nearest reflection data publicly available are in the Socorro area, about 80 km north of the present study area (Brown and others, 1980). These data were acquired by the Consortium for Continental Reflection Profiling (COCORP), a public-supported research group, to investigate the possibility of magma beneath part of the Rio Grande valley. Up to 1978 there were about 36 deep borings in the region of southwest New Mexico (Thompson and others, 1978). This drilling resulted mainly from an evaluation of petroleum potential of the Pedrogosa basin which is an extensive area of Paleozoic subsidence in Arizona, New Mexico, and Mexico that accumulated about three kilometers of Paleozoic sedimentary rock (Zeller, 1965; Thompson and others, 1978). Of these drill holes, 25 are close enough to the present seismic sections to provide correlations of velocity to lithology, and to provide an estimate of the errors associated with depth-to-interface interpretations. This information is summarized prior to considering the implications of the seismic sections in detail. The major portion of the report centers around two plates: Plate I shows seismic lines and selected drill hole locations superimposed on gravity contours, and Plate II shows velocitysections with drill hole summaries. These plates provide the foundation for developing inferences on buried lithologic, structural, and mineral resources for the region.

New Mexico↗
USGS1995

Water Resources Data, New Mexico, Water Year 1994

Water-resources data for the 1994 water year for New Mexico consist of records of discharge and water quality of streams; stage, contents, and water quality of lakes and reservoirs; and water levels and water quality in wells and springs. This report contains discharge records for 184 gaging stations; stage and contents for 26 lakes and reservoirs; water quality for 51 gaging stations and 72 wells; and water levels at 132 observation wells. Also included are 109 crest-stage partial-record stations. Additional water data were collected at various sites, not involved in the systematic data collection program, and are published as miscellaneous measurements. These data represent that part of the National Water Data System collected by the U.S. Geological Survey and cooperating State and Federal agencies in New Mexico.

New Mexico↗
USGS1995

Erosion assessment at the Petroglyph National Monument area, Albuquerque, New Mexico

Areas of the Petroglyph National Monument, specifically those located along the West Mesa escarpment, are being affected by erosion and gullying. A reconnaissance along the 17-mile-long escarpment identified 50 gullies. The gullies were given a qualitative ranking of Class I, least erosion, to Class IV, highest erosion. Of the 50 gullies identified, 21 were assigned Class I, 22 to Class II, 6 to Class III, and 1 to Class IV. Although the gullies may not be a direct threat to petroglyphs, the effects of gullying may have a greater effect on the aesthetics of the monument and the residences located downgradient from a gully. Most of the gullies were found along the northern part of the escarpment. This area, which is more developed than the southern areas of the escarpment, contains many dirt roads and nonpaved foot and bicycle paths. These features channel surface runoff and increase erosion. Thirty of the 50 gullies were noted as being connected to the runoff from dirt roads. High-intensity storms during the summer of 1991 may have caused or increased gullying. Analyses of these storms indicate recurrence intervals of rainfall of no more than 2 years. Indirect measurements of peak discharge in La Boca Negra Arroyo after the August 22, 1991, storm indicate that this runoff event may have a frequency of no more than 10 years. Regional frequency reports on rainfall and data collected at the rain gages indicate that gullying and erosion that occurred during the summer of 1991 were not a result of infrequent rainfall or runoff events.

New Mexico↗
USGS1995

Simulation of ground-water flow in the Albuquerque Basin, central New Mexico, 1901-1994, with projections to 2020

This report describes a three-dimensional finite-difference ground-water-flow model of the Santa Fe Group aquifer system in the Albuquerque Basin, which comprises the Santa Fe Group (late Oligocene to middle Pleistocene age) and overlying valley and basin-fill deposits (Pleistocene to Holocene age). The model is designed to be flexible and adaptive to new geologic and hydrologic information as it becomes available, by using a geographic information system as a data-base manager to interface with the model. The aquifer system was defined and quantified in the model consistent with the current (July 1994) understanding of the structural and geohydrologic framework of the basin. Rather than putting the model through a rigorous calibration process, discrepancies between simulated and measured responses in hydraulic head were taken to indicate that the understanding of a local part of the aquifer system was incomplete or incorrect. The model simulates ground-water flow over an area of about 2,400 square miles to a depth of 1,730 to about 2,020 feet below the water table with 244 rows, 178 columns, and 11 layers. Of the 477,752 cells in the model, 310,376 are active. The top four model layers approximate the 80- foot thickness of alluvium in the incised and refilled valley of the Rio Grande to provide detail of the effect of ground-water withdrawals on the surface-water system. Away from the valley, these four layers represent the interval within the Santa Fe Group aquifer system between the computed predevelopment water table and a level 80 feet below the grade of the Rio Grande. The simulations include initial conditions (steady-state), the 1901-1994 historical period, and four possible ground-water withdrawal scenarios from 1994 to 2020. The model indicates that for the year ending in March 1994, net surface-water loss in the basin resulting from the City of Albuquerque's ground-water withdrawal totaled about 53,000 acre-feet. The balance of the about 123,000 acre-feet of withdrawal came from aquifer storage depletion (about 67,800 acre-feet) and captured or salvaged evapotranspiration (about 2,500 acrefeet). In the four scenarios projected from 1994 to 2020, City of Albuquerque annual withdrawals ranged from about 98,700 to about 177,000 acre-feet by the year 2020. The range of resulting surface-water loss was from about 62,000 to about 77,000 acre-feet. The range of aquifer storage depletion was from about 33,400 to about 95,900 acre-feet. Captured evapotranspiration and drain-return flow remained nearly constant for all scenarios. From 1994 to 2020, maximum projected declines in hydraulic head in the primary water-production zone of the aquifer (model layer 9) for the four scenarios ranged from 55 to 164 feet east of the Rio Grande and from 91 to 258 feet west of the river. Average declines in a 383.7-square-mile area around Albuquerque ranged from 28 to 65 feet in the production zone for the same period.

New Mexico↗
USGS1995

Infiltration and quality of water for two arroyo channels, Albuquerque, New Mexico, 1988-92

Selected reaches of Grant Line Arroyo and Tijeras Arroyo in Albuquerque, New Mexico, were studied to collect information about the amount and quality of infiltration through arroyo channels. Infiltration rate was calculated for selected reaches of Grant Line Arroyo and Tijeras Arroyo based on instantaneous streamflow-loss volumes, wetted channel area, and instantaneous evaporation rates measured during 1988-92. Infiltration rates at Grant Line Arroyo ranged from 0.0 to 0.6 foot per day, and at Tijeras Arroyo from 2.28 to 30 feet per day. The evaporation rate ranged from one-tenth of 1 percent to 2 percent of the infiltration rate. Infiltration rates differed with the location of the reach isolated for measurement and with the time of day of the infiltration-rate measurement. Differences in intrinsic permeability of the sediments may be the most important factor affecting spatial variations in infiltration. The most important factor affecting temporal variations in infiltration may be the temperature of the water and sediment where infiltration occurs. Annual evaporation rates were greatest over saturated stream sediments and ranged from 802 to 1,025 millimeters per year or from 31.57 to 40.35 inches per year. Annual evaporation rates were least over unsaturated, unvegetated soil and ranged from 174 to 291 millimeters per year or from 6.85 to 11.46 inches per year. Annual evapotranspiration rates over grasses or shrubs or both were about one-half the rates over saturated stream sediments. Rates were similar for Grant Line and Tijeras Arroyos. The land- surface vegetation, availability of water at the land surface, availability of energy to enable a change of state from water to vapor, existence of a vapor concentration gradient, and a turbulent atmosphere to carry the vapor away may be the factors that determine the amount of evaporation and evapotranspiration. Water in Grant Line Arroyo and Tijeras Arroyo met U. S. Environmental Protection Agency drinking-water regulations for nitrate, volatile organic compounds, dissolved lead, and dissolved and total arsenic, barium, cadmium, chromium, copper, iron, silver, zinc, selenium, chloride, and sulfate concentrations. Total lead concentration in one sample from Tramway Floodway Channel, a tributary to Tijeras Arroyo, was 55 micrograms per liter, exceeding the Environmental Protection Agency drinking-water regulation of 50 micrograms per liter. Dissolved-solids concentrations calculated from the sum of cations and anions usually exceeded the Environmental Protection Agency drinking-water dissolved-solids regulation of 500 milligrams per liter at Tijeras Arroyo above Four Hills Bridge.

New Mexico↗
USGS1994

Geochemical evolution of groundwater in the Culebra dolomite near the Waste Isolation Pilot Plant, southeastern New Mexico, USA

The Culebra Dolomite Member of the Rustler Formation, a thin (10 m) fractured dolomite aquifer, lies approximately 450 m above the repository horizon of the Waste Isolation Pilot Plant (WIPP) in southeastern New Mexico, USA. Salinities of water in the Culebra range roughly from 10,000 to 200,000 mg/L within the WIPP site. A proposed model for the post-Pleistocene hydrochemical evolution of the Culebra tentatively identifies the major sources and sinks for many of the groundwater solutes. Reaction-path simulations with the PHRQPITZ code suggest that the Culebra dolomite is a partial chemical equilibrium system whose composition is controlled by an irreversible process (dissolution of evaporites) and equilibrium with gypsum and calcite. Net geochemical reactions along postulated modern flow paths, calculated with the NETPATH code, include dissolution of halite, carbonate and evaporite salts, and ion exchange. R-mode principal component analysis revealed correlations among the concentrations of Si, Mg, pH, Li, and B that are consistent with several clay-water reactions. The results of the geochemical calculations and mineralogical data are consistent with the following hydrochemical model: 1. solutes are added to the Culebra by dissolution of evaporite minerals 2. the solubilities of gypsum and calcite increase as the salinity increases; these minerals dissolve as chemical equilibrium is maintained between them and the groundwater 3. equilibrium is not maintained between the waters and dolomite; sufficient Mg is added to the waters by dissolution of accessory carnallite or polyhalite such that the degree of dolomite supersaturation increases with ionic strength 4. clays within the fractures and rock matrix exert some control on the distribution of Li, B, Mg, and Si via sorption, ion exchange, and dissolution.

New Mexico↗
USGS1994

Water-resources activities of the U.S. Geological Survey in New Mexico, fiscal year 1992

Awareness of our environment in general, and water resources in particular, has brought increased interest in and support of hydrologic data collection and research. The quantity, quality, and distribution of water are extremely important to the future well-being of New Mexico. The State's surface-water resources are minimal and highly variable due to climate and to regulation and diversion; ground-water resources are subject to development that exceeds natural recharge and to potential contamination by land use. Issues related to global climate change, disposal of hazardous wastes, toxic substances in water, water rights, and ground-water contamination are evolving areas of greater public concern. At the same time there is a continuing need for a better understanding of various hydrologic systems and processes in order to manage these limited water resources for maximum benefit to present and future generations. The U.S. Geological Survey has collected and disseminated information on the water resources of New Mexico for more than a century. The Survey began to collect records of streamflow in New Mexico in December 1888 when the first discharge measurements were made on the Rio Grande near the present gaging station at Embudo. This site, called the "birthplace of systematic stream gaging," was chosen to be the training center for the first hydrographers of the Irrigation Survey, a bureau within the original Geological Survey. Since that time, in cooperation with Federal, State, local, and tribal agencies, we have monitored streams at hundreds of sites throughout the State and have a current network of more than 200 streamflow-gaging stations. Through the Cooperative Program, we also have established sites where ground-water levels are monitored to document changes in ground-water storage or where surface-water and groundwater samples are collected to determine water chemistry, and we have undertaken investigative studies to define the availability, quality, and distribution of water resources. Information from the data program and results of investigative studies are made available to water-resources managers, regulators, and the public to be used for the effective management of the State's water resources. This report provides a brief summary of the activities of the New Mexico District for FY (fiscal year) 1992, including our mission, organization, sources of funding, and descriptions of current projects. This report serves to document not only the content of the program, but also the diversity and complexity of that program. Cooperation among water-resources agencies will be essential in effectively dealing with water-related issues facing New Mexico. We look forward to the challenge of addressing these issues by continuing to provide factual hydrologic data and technically sound areal appraisals and interpretive studies.

New Mexico↗