By: Daniel Tush
Emporia State University GO 571
GO 571, Hydrogeology, Spring 2007
The Roswell Basin Aquifer, as one might expect, is located near the city of Roswell, New Mexico. The aquifer stretches from somewhere of Roswell and south to nearly Carlsbad, a distance of greater than 75 miles. East to west, it measures about 25 miles across. In terms of area, it is definitely not one of the largest aquifers.
Image from USGS: http://capp.water.usgs.gov/aquiferBasics/ext_roswellb.html
The yearly average high temperature at the Roswell Airport is 75.6 F and the average low is 46.7. The average yearly precipitation is 12.98" (Western Regional Climate Center,WWW). The yearly pan evaporation rate for the Roswell Airport is 88 inches, ranging from a low of 2.9 inches in January to a high of 13 inches in June (Oregon Climate Service,WWW). For sake of comparison, Wichita has an average high temp of 67.4 F and an average low of 45.0 F with a yearly rainfall at 29.33" (National Oceanic & Atmospheric Administration,WWW). Roswell has an average relative humidity of 29% while Wichita is 49% (NOAA Satellite and Information Service,WWW). It should be expected that Wichita would have lower pan evaporation rates than Roswell due to its cooler temperatures and higher humidity. Add to this the fact that Roswell receives much less rainfall and it becomes readily apparent that water can be a precious commodity in the area around the Roswell Basin Aquifer.
The aquifer is recharged from two major sources. The first is the Pecos River and the second is from precipitation infiltration (USGS 2,WWW)
Flowing directly over the Roswell Basin Aquifer is the Pecos River. Both the Bottomless Lakes and Brantley Lake are also nearby. The Bottomless Lakes are actually fed by upward movement of groundwater (New Mexico Bureau of Geology and Mineral Resources,WWW). Brantley Lake is formed by a dam constructed on the Pecos river.
Image from newmexico.org: http://www.newmexico.org/go/loc/bymap/page/bymap-lakesmap.html
Image from newmexico.org: http://www.nmenv.state.nm.us/gwb/GWQ_Atlas/geomap.gif
The Roswell Basin aquifer is essentially two separate aquifers that are interconnected. The first part, where the Pecos River runs, is an alluvial aquifer. This part of the aquifer is composed of unconsolidated materials ranging is size from gravel to clays. The remainder of the aquifer is carbonate-rock, primarily limestone and dolomite (USGS 3,WWW).
The aquifer is a leaky, confined aquifer. The transmissivity in one area of the aquifer has been determined to be approximately 20,000 square feet per day (New Mexico Office of the State Engineer,WWW).
Click image to enlarge
Image from newmexico.org: http://www.nmenv.state.nm.us/gwb/GWQ_Atlas/freshgw.jpg
Click image to enlarge
Image from newmexico.org: http://www.nmenv.state.nm.us/gwb/GWQ_Atlas/aquiferyield.jpg
The type of water in the aquifer varies depending on location. Generally, the aquifer's water is considered very hard with high concentrations of calcium and magnesium. The calcium concentrations tend to range from one to five hundred parts per million while the magnesium concentration is from fifty to one-hundred thirty parts per million. In some parts of the aquifer, primarily the northeastern edge, the amount of sodium and chloride (rock salt) increased to levels high enough to change the classification of the water there to sodium chloride type (USGS 2,WWW).
Image from USGS: http://capp.water.usgs.gov/gwa/ch_c/jpeg/C106.jpeg
Unfortunately, all is not well in the aquifer. In the city of Roswell alone, there are three superfund or potential superfund sites. The site on the final National Priorities List use due to a plume of perchloroethylene (EPA,WWW).
Image from chemfinder.com: http://chemfinder.cambridgesoft.com/
Perchloroethylene, or 1,1,2,2-tetrachloroethylene, is a chemical compound with a molecular weight of 165.8 that is a liquid at room temperature, with a melting point of -22.3 C and a boiling point of 121.1 C (chemfinder.com,WWW). It's non-polar character give it the ability as a solvent to dissolve a large number of various organic materials which is why it was used in the dry cleaning industry. Introduced into the body it has a negative impact on the central nervous system, the liver, the kidneys, and can cause several other symptoms (CDC,WWW).
The New Mexico Office of the State Engineer (http://www.ose.state.nm.us/) is the state body in charge of water resources. The New Mexico Environmental Department contains the Drinking Water Bureau (http://www.nmenv.state.nm.us/dwb/dwbtop.html), the Ground Water Quality Bureau (http://www.nmenv.state.nm.us/gwb/gwqbhome.html), the Surface Water Quality Bureau (http://www.nmenv.state.nm.us/SWQB/), as well as various waste bureaus.
USGS, http://capp.water.usgs.gov/aquiferBasics/ext_roswellb.html (Accessed 4/21/2007)
Western Regional Climate Center, http://www.wrcc.dri.edu/cgi-bin/cliMAIN.pl?nm7610 (Accessed 4/21/2007)
Oregon Climate Service, http://www.ocs.orst.edu/page_links/comparative_climate/new_mexico/new_mexico.html (Accessed 4/21/2007)
National Oceanic & Atmospheric Administration, http://www.crh.noaa.gov/ict/?n=yearly (Accessed 4/21/2007)
NOAA Satellite and Information Service), http://lwf.ncdc.noaa.gov/oa/climate/online/ccd/avgrh.html (Accessed 4/21/2007)
USGS 2, http://capp.water.usgs.gov/gwa/ch_c/C-text7.html (Accessed 4/21/2007)
New Mexico Bureau of Geology and Mineral Resources, http://geoinfo.nmt.edu/tour/state/bottomless_lakes/home.html (Accessed 4/21/2007)
USGS 3, http://capp.water.usgs.gov/gwa/ch_c/C-text1.html (Accessed 4/21/2007)
New Mexico Office of the State Engineer, http://www.ose.state.nm.us/PDF/ISC/ISC-Compacts/Pecos/FinalReport_Recalib_Jun23_2004.pdf (Accessed 4/21/2007)
EPA, http://cfpub.epa.gov/supercpad/cursites/csitinfo.cfm?id=0605386 (Accessed 4/21/2007)
chemfinder.com, http://chemfinder.cambridgesoft.com/result.asp (Accessed 4/21/2007)
CDC, http://www.cdc.gov/niosh/hc17.html (Accessed 4/21/2007)