LEADER 01646nam  2200421   450 
001 9910704432503321
005 20150708093836.0
035   $a(CKB)5470000002441372
035   $a(OCoLC)913472189
035   $a(EXLCZ)995470000002441372
100   $a20150708d2012      ua             0
101 0 $aeng
135   $aurcn|||||||||
181   $ctxt$2rdacontent
182   $cc$2rdamedia
183   $acr$2rdacarrier
200 10$aUse of classes based on redox and groundwater age to characterize the susceptibility of principal aquifers to changes in nitrate concentrations, 1991 to 2010 /$fby P.B. McMahon
210  1$aReston, Virginia :$cU.S. Department of the Interior, U.S. Geological Survey,$d2012.
215   $a1 online resource (51 unnumbered pages) $ccolor illustrations, color maps
225 1 $aScientific investigations report ;$v2012-5220
300   $aTitle from title screen (viewed on July 2, 2015).
320   $aIncludes bibliographical references (pages 33-35).
606   $aGroundwater$xAnalysis
606   $aAquifers$zUnited States$xAnalysis
606   $aGroundwater$xPollution
606   $aNitrates
615  0$aGroundwater$xAnalysis.
615  0$aAquifers$xAnalysis.
615  0$aGroundwater$xPollution.
615  0$aNitrates.
700   $aMcMahon$b Peter B.$01387740
712 02$aGeological Survey (U.S.),
801  0$bGPO
801  1$bGPO
906   $aBOOK
912   $a9910704432503321
996   $aUse of classes based on redox and groundwater age to characterize the susceptibility of principal aquifers to changes in nitrate concentrations, 1991 to 2010$93528232
997   $aUNINA