Water quality of the Ogallala Formation, central High Plains aquifer within the North Plains Groundwater Conservation District, Texas Panhandle, 2012-13

Scientific Investigations Report 2014-5188
Prepared in cooperation with the North Plains Groundwater Conservation District
By: , and 

Links

Abstract

In cooperation with the North Plains Groundwater Conservation District (NPGCD), the U.S. Geological Survey collected and analyzed water-quality samples at 30 groundwater monitor wells in the NPGCD in the Texas Panhandle. All of the wells were completed in the Ogallala Formation of the central High Plains aquifer. Samples from each well were collected during February–March 2012 and in March 2013. Depth to groundwater in feet below land surface was measured at each well before sampling to determine the water-quality sampling depths. Water-quality samples were analyzed for physical properties, major ions, nutrients, and trace metals, and 6 of the 30 samples were analyzed for pesticides. There was a strong relation between specific conductance and dissolved solids as evidenced by a coefficient of determination (R2) value of 0.98. The dissolved-solids concentration in water from five wells exceeded the secondary drinking-water standard of 500 milligrams per liter set by the U.S. Environmental Protection Agency. Water from 3 of these 5 wells was near the north central part of the NPGCD. Nitrate values exceeded the U.S. Environmental Protection Agency maximum contaminant level of 10 milligrams per liter in 2 of the 30 wells. A sodium-adsorption ratio of 23.4 was measured in the sample collected from well Da-3589 in Dallam County, with the next largest sodium-adsorption ratio measured in the sample collected from well Da-3588 (12.5), also in Dallum County. The sodium-adsorption ratios measured in all other samples were less than 10. The groundwater was generally a mixed cation-bicarbonate plus carbonate type. Twenty-three trace elements were analyzed, and no concentrations exceeded the secondary drinking-water standard or maximum contaminant level set by the U.S. Environmental Protection Agency for water supplies. In 2012, 6 of the 30 wells were sampled for commonly used pesticides. Atrazine and its degradate 2-Chloro-4-isopropylamino-6-amino-s-triazine were detected in two samples. Tebuthiuron was detected in one sample at a detection level below the reporting level but above the long-term method detection level. There were no detections of the glyphosate, aminomethylphosphonic acid (AMPA), or glufosinate.

Additional publication details

Publication type Report
Publication Subtype USGS Numbered Series
Title Water quality of the Ogallala Formation, central High Plains aquifer within the North Plains Groundwater Conservation District, Texas Panhandle, 2012-13
Series title Scientific Investigations Report
Series number 2014-5188
DOI 10.3133/sir20145188
Year Published 2014
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Texas Water Science Center
Description Report: vi, 64 p.; 2 Appendixes
Time Range Start 2012-01-01
Time Range End 2013-12-31
Country United States
State Texas
Other Geospatial Texas Panhandle
Datum North American Datum of 1983
Projection Albers Equal-Area Conic projection
Scale 1000000
Online Only (Y/N) Y
Additional Online Files (Y/N) N