Laserfiche WebLink
<br />. <br /> <br />intense lateral pressures on the <br />intervening sedimenta~y formations, <br />resulting in ~arp~ng and fracturing <br />along weak zones. Under these pres- <br />sures and the weight 0: the over- <br />lying formations, a deeply buried <br />layer of salt (Paradox Member) from <br />an ancient inlan~ sea has flowed <br />upward into the :~2c:~red area of <br />the :old to crea:e a~ elongated <br />swell knm.,,,:: as 2D or,::.:line. As <br />this nos :aken piece, :~e Dolores <br />River has remaine~ i~ i~s origi~aJ <br />streambed and, in co~j~~ction <br />with weathering an~ e~osian~ has <br />remove~ the ~pp~r sa~e~ia~s to <br />for~ the ~alle-.'" :~ES2 geologic2: <br />processes ar~ s:i:: active today <br />in the valle\'. <br /> <br />Grounc Hater comes inte <br />contact ~i:h the :C~ o~ the salt <br />formation, i~'here i:: becoIT.es <br />nearly saturated, an~ surfaces <br />as salt brine in the channel of <br />the Dolores River nea~ :~e middle <br />of the valley. :~~ e~~ect of the <br />brine varies cons~~c~c~:y, depend- <br />ing upo~ ~he am0L;:~ c~ ~ater in <br />the ri,,:er. ~:~;:, :-::'\'E-:~lo'.,:s :nix <br />with an~ ccnsicie~~~ly ~il~te tile <br />brinEj conseque;;~:::~ r:-.e salt <br />content of the stre2~ ~2Y increase <br />rroffi 120 ~illigr2~s per ~lter <br />(mg!I) as it en:ers the valle~- <br />to 150 ~g/l 2S it ex:::s the val]e~. <br />With lo~ riverflo~s, however, the <br />salinity o~ the r~ver increases <br />from 3,700 mg/I to as ~igh as <br />166,000 ng!l (approxinately five <br />times as saline as sea ~ater) as <br />it crosses Paradox \'a~~ey. <br /> <br />Current PIe:-, <br /> <br />In its Defini::e ~'lan Report <br />the Service recon-nended tha t a <br />series of wells be drilled on both <br />sides cf the river i~to the brine <br />zone tC' ?un;p the 521i:-:e ground <br /> <br />. <br /> <br />water. InlS pumping would lower <br />tile inter~ace between the relatively <br />~res~l groun~ water and the underlying <br />orlne. The brine would be pumped <br />from the well field to an evaporation <br />?ond in Dry Creek Basin. <br /> <br />After [he Definite Plan Report <br />~2S publishe~ a decision to furthe~ <br />investigate deep well injection of <br />t~e brine for disposal was mace, <br />~~is Gispos~l metho~ 2S well ~s t~~ <br />us~ 0: a~ eva~oration pond, will ~2 <br />studied. <br /> <br />!he ?la~~i~g and develop~e~: ~_ <br />r~ject facilities consists or co:- <br />:ecting design data in several are2~" <br />J..:-st, ::-,e required pumping ope~2: ic:-. <br />:0 co~tro~ ~rine inflow to the DolcrE~ <br />?\i",'er i-,7ill be determined. Along i,'it:~ <br />:hi~ brine ~isposal methods will be <br />:~oroughly analyzed. Finally, metl1o~s <br />:0 re~uce hydrogen sulfide levels <br />25s0ciate~ with the brine will te <br />:2s:e~. :~i:h this informacion, ~etEr- <br />~.~~ations ~ill be made as to the a~~- <br />.: ~:.::.c:: C':' "",'e~~ :ield coverage, .fi;;L~~ <br />::c:sig:1 0: :::€ :-:~'drogen sulfide re~:C'.,.::; <br />~ .,ci:i :iE:3. :inal pUr.1ping pIa;:: L:::1C: <br />~i?~:ine desi;n. an~ desig!l 0~ :j~e <br />~~spcs21 facilities. <br /> <br />~~e drilling of test well~. <br />~::s:allatic~ 2~ pumps, construc:i(::1 <br />:~ a temporary pipeline, and co~stru:- <br />:i2il of a temporary brine storage <br />~c:1d haVE: been completed. Test h'e:2 <br />:''.l;;;ping bega~ in January 1980. <br /> <br />The pumped brine is temporal'i~:" <br />22ing stored during the design cat2 <br />collection period in a storage pond <br />.~:.1st dOi,,rnstrean of the brine i-,Tell <br />field. The data being collecte~ to <br />assess the pumping impact incltldes <br />clectroccnductivity at several points <br />32.ong the river, i.;ater samples abo'..e <br />a~d belo~ the well field, groun~ water <br />sa~ples, brine-fresh water inte]-~ncc <br /> <br />G00014 <br />