iv Figures 1—Areas described in published water resources reports inside front cover 2—Index map of report area vi 3—Diagram showing system of numbering wells and springs 8 4—Map showing geology, water-level contours, and selected wells and springs in pocket 5—Piper diagram for water from Precambrian rocks 11 6—Piper diagram for water from the Madera Limestone and the Sandia Formation 12 7—Solution holes on bedding plane in Madera Limestone, Cedro Canyon 13 8—Piper diagram for water from Permian formations 15 9—Piper diagram for water from the Chinle Formation 17 10—Piper diagram for water from Jurassic and Cretaceous formations 18 11—Piper diagram for water from Estancia Valley fill, Santa Fe Group, and Madera Limestone 20 12—Piper diagram for water from alluvium 21 13—Monthly precipitation in the Sandia Mountains for the period 1959-68 22 14—Section A-A ' from crest of the Manzano Mountains to Estancia Valley 2: 15—Section B-B ' from crest of the Sandia Mountains to the Edgewood embayment 24 16—Ground-water flow lines at San Antonito and upper Tijeras Canyon 25 17—Well locations and water depths near Frost Arroyo 26 18—Water-level altitude vs bottom-hole altitude near Frost Arroyo 26 19—Section C-C ' near Placitas 28 20—Map showing areas having similar ground-water conditions 30 21—Distribution of producible wells and dry holes in Madera Limestone 34 22—Distribution of wells and springs with appreciable concentrations of fluoride, carbon dioxide, and nitrate 37 Abstract Large supplies of ground water are not available in the Sandia and northern Manzano Mountains east of Albuquerque, New Mexico. In lower Tijeras Canyon maximum water yield from wells was reported to be greater than 50 gallons per minute. Average dissolved- solids concentration is 462 milligrams per liter. In middle Tijeras Canyon well yields are usually below 40 gallons per minute with no water-quality problems. In the Tijeras anticline and syncline area well yields range from less than 1 gallon per minute to 35 gallons per minute. Dissolved-solids concentrations were as high as 1,070 milligrams per liter. Measured well yields in the lower Sandia slopes and Frost Arroyo area are as great as 180 gallons per minute. Water quality in this area generally meets Environmental Protection Agency standards. The Madera Limestone, a major source of water, crops out over higher parts of the Manzano Mountains and over all the eastern dip slope. It also crops out on more than half of the Sandia Mountain dip slope and underlies the valley fill of the Estancia Valley. One in every five wells drilled in the Madera can be considered dry (less than 0.10 gallon per minute). Wells near Tps. 6-8 N., Rs. 7-8 E. will commonly produce more than 1,000 gallons per minute. In the Placitas area nearly all formations have been drilled for water and yields are adequate for domestic use except from the Mancos Shale. Quality is acceptable if the well is finished above the Entrada Sandstone and Todilto Limestone. Introduction The Sandia Mountains and northern Manzano Moun- tains, but geologic details of the Sandia Mountains did not tains are situated east and southeast, respectively, of begin appearing in publication until the 1961 Guidebook of Albuquerque in parts of Bernalillo, Torrance, Sandoval, the New Mexico Geological Society (Northrop, 1961). and Santa Fe Counties in central New Mexico (fig. 2). Kelley (1963) prepared a geologic map of the Sandia The mountains form the bold escarpment on the east side Mountains and northern extremes of the Manzano of the Rio Grande valley. From their crests the slopes Mountains, and D. A. Myers produced four detailed incline steeply to gently eastward toward Estancia quadrangle maps in the Manzano Mountains, two co- Valley. The two ranges lie end-to-end in a north-south authored with McKay. For the layman who is interested in direction and are separated by Tijeras Canyon. Sandia the geology of the Sandia Mountains, the description by Crest is the highest point in both ranges with an altitude Kelley (1974) in Albuquerque, its mountains, valley, water, of 10,678 ft—more than 4,000 ft above the alluvial fans and volcanoes is recommended reading. at the foot of the rugged west face. Bosque Peak, with an The hydrologic conditions have not been studied as altitude of 9,610 ft, is the highest point in the Manzanos intensively as has been the geology. Smith (1957) within the area studied. described the general ground-water conditions in the The study area includes all of the Sandia Mountains Manzano Mountains as part of a ground-water study in and the northern part of the Manzanos. The study area is Torrance County. The hydro geologic conditions in the about 45 mi long and 20 mi wide. It straddles the ranges Manzanos and easternmost Sandias were described by from the fan heads at the foot of the west-facing scarps Titus (1969). eastward to the gentle alluvial slopes beyond the bedrock outcrops in Estancia Valley. A few decades ago the population of the mountain area Data collected and limits of project was small and was localized in a few communities or on This report is based on hydrologic data collected from small ranches. Since World War II, many of the old 1960 to 1964. The data were obtained from existing communities have been deserted and most of the ranches wells and springs and are based on field observation. have been subdivided. Increasing numbers of people When possible, additional information was obtained interested in owning mountain vacation cabins or from the owner, user, driller, or other person who had permanent homes have moved to the mountains and have knowledge of the well or spring. The chemical analyses tended to build on lots of an acre or so. of water that are reported here were made in the The former residents needed only a small water sup- Albuquerque laboratory of the USGS. The water-level ply for domestic purposes—usually not more than contours and water-quality interpretations reflect the could be carried from the well to the kitchen. The old conditions during the early 1960's. communities were located near known supplies of The data were compiled and the report prepared by the ground water, frequently springs. The ranchers needed author in 1973. Before publication details could be worked a well with a windmill to supply water for stock, and out between the USGS and the New Mexico Bureau of the same well, when near the ranch house, also served Mines and Mineral Resources, the author left the state. domestic needs. In contrast, the new residents came to Because of the need to make the data available and the the mountains expecting city water conveniences. With intense interest in the Sandia-Manzano Mountain area, the few exceptions they were aware that each must report was prepared for publication by the USGS in 1977 construct his own water system—well and pump—but and 1978. The author expresses gratitude to the many need was seen as the criterion for design, not people who supplied basic information for the hydrogeologic availability of ground water. interpretations presented here. Most geologic data were compiled from published Purpose and scope maps after considerable field checking and limited The purpose of this report is to describe the ground- checking against aerial photographs. Modifications of water availability and quality in the aquifers of the San- the geology from published sources are limited mainly to dia and northern Manzano Mountains. This project has adding some unmapped faults to the Madera terrain been undertaken cooperatively between the New south of Tijeras Canyon and to the Santa Fe terrain in Mexico Bureau of Mines and Mineral Resources, the the northwest corner of the map. Two previously un- Office of the New Mexico State Engineer, and the U.S. mapped 71/2 -minute quadrangles were geologically Geological Survey (USGS). The study was not designed mapped for the project by field and photo geologic tech- to give quantitative answers about the ground-water niques. supply. Aquifer tests were not made. Estimate of ground water in storage was not attempted. Nor were predictions made about water-level changes in areas of Factors for converting inch-pound units to withdrawal. The study shows the relationship between metric units geology and ground-water availability. In this report figures for measurements are given in inch-pound units only except for chemical analyses, Previous work which are given in milligrams per liter (mg/L). The A few general references are mentioned here. Reiche following table contains factors for converting to metric (1949) described the geology of the Manzano Moun units. Well-numbering system In this report numbers used to identify wells and springs also give their locations. The system used by the USGS and the New Mexico State Engineer is based on the common land subdivision by section, township, and range, as illustrated in fig. 3. Each well and spring within the area of this study is assigned a number that consists of four segments separated by periods. The first segment denotes the township north of the New Mexico base line, the second segment denotes the range east of the New Mexico principal meridian, and the third seg- ment denotes the section within the township. The fourth segment of the well number consists of three digits that denote the particular 10-acre tract in fixes a, b, c added to the well numbers. In special cases which the well is located within the section. The section where the location of the well cannot be determined to is quartered, and the quarters are numbered in normal within a 10-acre tract, a zero is used for the third digit; reading order.