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<br />I SENT BY: BOR-WCAOS SD; .,--'
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<br />8-16-96 4:52PM; 970 385 6539 ->
<br />.)0 tlUM.WCAOI eDi .17
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<br />303 866 4474; #16122
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<br />SWQB/NME.D Summary
<br />August 12, 1996
<br />Pare 14
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<br />v.ill therefore JWeive few, if any, benefits from the proposed Projet.'t and will suffer the brunt of
<br />adverse: environro.f:ntal impacts,
<br />
<br />Sml~ JIIntf 'trace Ellft'metlt An.1Y!li~
<br />
<br />"Bcca\lSC of concerns about hazardous return floW\! and associated impactll to aquatic life and water
<br />quality, a mote c.omprchc:mivc study was made for this PIoject than , . . for most projects,"
<br />
<br />lbc Soils and Trace Element Analysis (Appendix F) lists the ieomemc means of the soluble and
<br />1Otall!JCleniumon the seven landforms studied in the La Plata Riwr Project area. Levels ranged from
<br />2.S ~&fL in the Valley L8.lIds to 4S.9 }J.gIL in the East Side Tcull\:o IRll of New Mexico. Total
<br />selenium in the soil ranaed from 149 ppb ill the Red Mesa Lands to 266 ppb in the Valley Lands.
<br />Thus. the Project Lands can be shown to contain relatively high levels of selenium. "In terms of the
<br />potential to create toxic or ha7.al'dous retum flows fTom Project lnigation, :soluble Se will be leached
<br />from the soilllnd inc_ gtO\,lJ\dwater conl:antTations of this element, particularly in the initial
<br />stalcS of iIrilJation."
<br />
<br />The Analysis contains the following conclusions concerning Project Lands:
<br />
<br />"Based solely on soils analysis, the Project Lands contain low to moderate concentrations of the
<br />traCe elements QOlISidered to be toxic 10 fish and wildlife. Project soils have relatively low total Sa
<br />concentrations. with only 3 of 317 sampl.. anslyzed having greater than 1,0 ppm Sa . ,. Se
<br />concentrations in nonseleniferous soils In tbe U,S. range from 0,1 to 2 mgikg (ppm), In seleniferous
<br />soils, Se llltlies &om I to 80 ppm, with Ililports of up to 1,200 ppm, Using this crlteria, Project soils
<br />would be considered no.aseleniferous. Project 801l5, particularly those of the East Side lIIl.d the Third
<br />Terrace and the Ute Mountain Ute portion ofUie Dry Side area do conJain signifi~t unoWlLB of
<br />the soluble forms of Se which will be mobilized. under irrigation/drainage conditions, The
<br />uncertainty at this time is the magnitude and duration of this mobilil'o&1ion . . ."
<br />
<br />"The lcvelJ oftotaI selenium found in soils is [$ic] wwparativelY 10wthrouP>ut the Project, Also.
<br />there are no sianifi<:ant Se loading SQIIIl:eS within the Project &rea. For the:se rcosons, long-term
<br />ImpllCts to irrillation munt flow watt:r quality are expected to be low." Y c:t, BOR removed more
<br />thm 2 1/4 square miles of lands which were to have been inipled by this projcd within New
<br />Mexico from lIUVille "[bJecause ofth8ir ~allD affect water quality in the La. Plata River from
<br />selenium loldlna."
<br />
<br />"Careful monitoring is IlilCOmrncnded for inIgation retum fiolA-'5 as they develop wi1h irrigation of
<br />Project IllIIda in the La Plata IlIId Mancos River Basins to IlllIke sure that IlIIIICCepl8.ble conditions do
<br />not OCCIlI." TI,_" I/O propos,tI pIa,. of do" s"ould """ IUl4Cceptabk cOlldUlDII' ocellr, I"
<br />ftICt, M" th, Project WlU' Ctnrrplllft, t"er. Wf1111tl H I''''' JrJiIlgtltiv. ,g,ms t!tlft coll14 re4au tll,
<br />sele1liu," CO"UIltrlftlDlU fro'" i"igllJioll ,IflIm flows witholll .clWe, uti opens/ve, tutituy
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