Flynn, Jennifer L., Arnold, L. Rick, and Paschke, Suzanne S. 2009 vector digital data Reston, VA U.S. Geological Survey http://water.usgs.gov/lookup/getspatial?ds472_randomsites Arnold, L.R., Flynn, J.L., and Paschke, S.S. 2009 report USGS Data Series Data Series 472 Reston, Virginia U.S. Geological Survey http://pubs.usgs.gov/ds/472/ These data are in support of report DS 456 (Arnold and others, 2009). This dataset includes 90 potential groundwater sampling sites randomly generated using techniques described in Scott (1990), composed of 30 locations with a first, second, and third choice of sampling location. Sites are in 30 equal area polygons that divide areas in the High Plains Aquifer in Colorado with a depth to water less than 180 feet, a saturated thickness greater than 50 feet, and underlying irrigated agricultural lands. Input saturated-thickness and depth-to-water data from V.L. McGuire, written communication, 2008. Irrigated agricultural lands from Bauder and others (2004). Wells are to be drilled at sites randomly located within areas meeting the criteria. This data set provides a first, second, and third choice randomly placed within 30 equal area polygons dividing all areas meeting the criteria. Bauder, T., Cipra, J., Waskom, R., and Gossenauer, M., 2004, Center pivot irrigation in Colorado as mapped by LANDSAT imagery: Colorado State University Agricultural Experiment Station Technical Bulletin TB04-04. Scott, J.C., 1990, Computerized stratified random site-selection approaches for design of a ground-water-quality sampling network: U.S. Geological Survey Water Resources Investigations Report 90-4101, 109 p. 2000 unknown ground condition Complete None planned -102.872220 -102.059940 40.716330 39.051440 None High Plains Aquifer inlandWaters None Eastern Colorado USA United States of America None None. Users of this geospatial database and geologic information derived there from should acknowledge the U.S. Geological Survey as the source of the data. U.S. Geological Survey Ask USGS -- Water Webserver Team mailing address

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Reston VA 20192 USA 1-888-275-8747 (1-888-ASK-USGS) http://answers.usgs.gov/cgi-bin/gsanswers?pemail=h2oteam&subject=GIS+Dataset+ds472_randomsites Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 3; ESRI ArcCatalog 9.2.6.1500 US Geological Survey, Colorado Water Science Center 2009 Data Series 456 Colorado State University Agricultural Experiment Station 2004 Colorado State University Agricultural Experiment Station Technical Bulletin TB04-04 U.S. Geological Survey 1990 Water Resources Investigations Report 90-4101 Point shapefile created with program described in Scott 1990. Checked against equal area polygon data ds472_equalareas. A 30 site network was randomly generated with one site in each of 30 equal area polygons meeting the criteria of saturated thickness greater than 50 ft, depth to water less than 180 ft, and underlying irrigated agricultural lands. A second and third choice site was also generated for each of the 30 areas. Checked against source data of saturated thickness, depth to water, and irrigated lands. Random Sites generated by aml described in Scott (1990). 2008 Vector Entity point 90 0.00001 0.00001 Decimal degrees North American Datum of 1983 Geodetic Reference System 80 6378137.000000 298.257222 ds472_randomsites Locations of first, second, and third choice sites placed randomly within each of 30 equal-area polygons overlying the High Plains Aquifer in Colorado and meeting criteria as described in Data Series 456. Data Series 472 FID Internal feature number. ESRI Sequential unique whole numbers that are automatically generated. Shape Feature geometry. ESRI Coordinates defining the features. Site Number identifying equal area polygon where the site is located. ds472_equalareas 1 30 0 Randomly placed site as described in Data Series 456. Round Identifies first, second, or third choice of site within the identified equal area polygon. Data Series 456 Identifier rank of site within equal area polygon as described in Data Series 456. 0 Not applicable, rank of first, second, or third choice. US Geological Survey Ask USGS -- Water Webserver Team (http://ask.usgs.gov/) mailing address

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Reston VA 20192 USA 1-888-275-8747 (1-888-ASK-USGS) http://water.usgs.gov/user_feedback_form.html Downloadable Data Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this information product, for the most part, is in the public domain, it also contains copyrighted material as noted in the text. Permission to reproduce copyrighted items for other than personal use must be secured from the copyright owner. This database, identified as Potential groundwater sampling sites for installation of a well network for long-term monitoring of agricultural chemicals in the High Plains Aquifer, Colorado, has been approved for release and publication by the Director of the USGS. Although this database has been subjected to rigorous review and is substantially complete, the USGS reserves the right to revise the data pursuant to further analysis and review. Furthermore, it is released on condition that neither the USGS nor the United States Government may be held liable for any damages resulting from its authorized or unauthorized use. Although these data have been processed successfully on a computer system at the U.S. Geological Survey, no warranty expressed or implied is made regarding the display or utility of the data on any other system, or for general or scientififc purposes, nor shall the act of distribution constitute any such warranty. The U.S. Geological Survey shall not be held liable for improper or incorrect use of the data described and/or contained herein. shapefile 0.002 http://water.usgs.gov/GIS/dsdl/ds472_randomsites.zip unzip None 20090320 US Geological Survey REQUIRED: The person responsible for the metadata information. Ask USGS -- Water Webserver Team mailing address

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Reston VA 20192 USA 1-888-275-8747 (1-888-ASK-USGS) http://answers.usgs.gov/cgi-bin/gsanswers?pemail=h2oteam&subject=GIS+Dataset+ds472_randomsites FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998