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May 1982- Issue #3 ~H:EK~:fl. flOi':~ L;,'lIT COLORADO RIV[R WATER QIIAI,lTY r~.II'R.OVF.MENT PROr.RAM PLAN:-ll~G n:AM NI':\~Su:rrEfl. .5 n~wsl~tter summdri7.es the r~sul tll of the verificl1- tion pr')~r.lm vn the ~l<'(~k,u nOln~ Hnit. Tho:: Fin.ll Verifi- cation Program Report was cl)(Tlpl<.!teo by CH2~1 Hill in Dec~mher 1981. InflJnn.1tlon on the monitoring n.:'twork and the activity on the Scott, Marland, and Jaln.:'s Wdls ..:;::::.. was presented in Issue 1~2 of the planning team news- ~ Letter. ~ BACKGROUND ~ The saLine seepage problem at Meeker Dome WAS believed to be the result of unplugged or inadequately plugeed oil test wells. Reclamatlon's consultant. CH2M Hill Central Inc.. carried out a verification program to test this hypothesis. six observation t.,'l2lls and eight seep measurement stations were installed in 1980 to monitor ground-water level and flows. A testing progra,n was initiated for three old oil explorRtion wells. By June 16, 1981. two wells were cleaned out and plugged; a third well was assumed to be plugger! through an inter- cept well. HYPOTHESIS VERIFICATION Data obtained in the course of the Meeker Dam.:! investi- gation have supported the hypothesis that saline water from deep confined aqui fers is reaching the surface by rechar~ing shallow, poorly-confined aquifers via old well bores. Information Obtained During the Verification Program ~re is a shallow aqui fer in the upper Morrison Fonna- n charged with sal int! water under fairly high head ich llnderlie~ mo.sr, if not all, of the Dome. The aquifer is within 60 feet of the surface ne<lr the Meeker Well. The 800-foot-deep Meeker Well. drillE:d in the early 1900's, penetrated aquifers in the Entrada Forma- tion. Meeker Well flowed into the White River at approxim<ltely 1,200 gpm for nearly 50 years. The Mar- land Well, drilled in 1925, encountered flowing \.iate.r in the Entrada and deeper formations to a depth of 2,000 feet. Each progressively deeper aquifer contained water that was higher in mineralization, temperature, and pressure. The Weber Formation from 1.800 to 2,000 feet yielded the highest pressure and flow and contained the saltiest water. Flows at the Meeker WeJ.1 responded to the interaquifer connection between th~ Weber and Entrada Formalions as a result of the M<lrland Hell. Both wells flowed simul- taneously for several ye':Hs before the Marland t.lell ceased flowing because of a partial well bore collRpse, intentional plugging with debris, and/or the graclu<ll bleed-off of pressure by the flowing wells. The Meeker Well continued to floW" until 1968, when it was plugged. Represnurizat ion occurred in tbe Ent rada and lower form- ations which resulted in sufficient pressure recovery at the Harland Well to push water to the surface. Insuffi- cient casing and corrosion of th~ casing resulted in conditions at the Marland Well whl~l-e shallow aquifers were intcrcp.pting lal"ge qllAntities of the Silline wat€r moving up the borehole from the deep aquifers. As shal- low formations were invaded by water from a deeper m~jor aquifer, w;lter quality in 1111 zones became nearly iden- IIIlIIiii.cal. Wteraquifer connections along deep f.lults, if in exis- tence <It all, did not provide avel1l!CS for movement of saline water to the surface until deep confining beds were p.~netrated by the Marland Well. Once charged with snlint> wat~r from deeper aquif~rs, joints and f.1LJlt pl<ln~s ..:Jllo....l=!d r:'1pid lateral and possibly vertical m.we- ment of thi.lt wat~r in And hetween shallow aqui fers (see Figure. 1). -' -' .. i< o z ,,-' -,-' z" "i< :> 0: .. " 0: 0: .. .. ... " r ~ __ ~ ,,----=..-=--:::.:= J..:,~-- ~'I 1::':1 .6:. , : :-.:~: : 1:'.-:-. I..... DA KOTA ---=-___CappinQ Layer ,:- ENTRADA MORRISON CasinQ 553'_ -._, DeplhSod .".: 1 Dcplh 2002' WEBER -------- fiGURE I WELL rLOW MECHANISM a.1EEKr.R DOLlE. AREA (1981) The Scott Well annulus (the area between the drill hole and the pipe casing)) poorly cemented above 1.500 feet, was essent ial ly free pipe wi th the potent ial for large volumes of saline water to rise around the pipe and flow into the Morrison Formation. TIle Marland Well WRS cased only to 553 feet. The casing was disintegrating ami the annulus behind the casing ....as open. After cement was pumped inlo the Marland Inter- cept Well, water le:\'els and flows issuing from the shal- low Morrison aquifer rapidly declined, indicating that a direct connection existed between deep and shallow aqui- fers at the Marland Well. Flowing water and an ope:n bore hole above 335 feet in the Jame~ Welt and water level response~ in nearby observation wells confirmed that the James Well connect- ed an nrtesian sal ine aquifer in the upper Morrison For- TIIation with the D.:Jkota Sandstone. The James Wdl was the primary SOLJrcc for local salt problems on the east 5 ide of the Dome. Nearly source idcnt ical water theory for all quality supports the wat~r encountered. common- Although