GEOPHYSICAL SURVEYS FOR CENTRAL AQUIFER OAHU, HAWAII
IGEOPHYSICAL SURVEYS FORGROUND WATER EVALUATIONCENTRAL AQUIFER ANDWEST ]3EACH AREASOAHU, HAWAII- .·.(
IIIGEOPHYSICAL SURVEYS FORGROUND WATER EVALUATIONCENTRAL AQUIFER ANDWEST BEACH AREASOAHU,HAWAII'-:·,, ,Prepared For:Ewa Plains Water Development Corporation-,Suitesoo,828 Fort Street MallHI96813Honolulu,Prepared By:Blackhawk Geosciences,Inc.17301 West Colfax Avenue, suite 170Golden, co80401April 10,1990(Our Project #90006)· . ' . - : - . ,,
IIII·1Table ofContentsPage1. 0INTRODUCTION.2.0LOGISTICS3. 0DATA PROCESSING.4. 0INTERPRETATION RESULTS5. 0 AND DATA ACQUISITION . . . . . . . . . . . . 4. 1GENERA.L.4. 2GEOELECTRIC CROSS-SECTIONS/CENTRA.L4.3GEOELECTRICCONCLUSIONS. . . . .AQUIFERCROSS-SECTION/WEST BEACH . . . . 125666910.,;··,
IIIIIIIII1.0INTRODUCTIONA time domain electromagnetic (TDEM) geophysical survey wasconducted from March 13 to March .21, 1990, on the Island of. Oahu,Hawaii, by Blackhawk Geosciences, Inc. (BGI) for Ewa Plains WaterDevelopment Corporation (EPWDC).The survey was performed toassist in the evaluation of the hydrogeologic section in twoareas Northwest of Waipahu(Central Aquifer area) Northwest of Honokai HaleThe objectives of the geophysical survey in the CentralAquifer area were:1.To map the depth, locationt and continuity ofimpermeable layers that mayhave formed at theunconformity between the Waianae and Koolau lava flows.2.To map the depth of the fresh - salt water interface oneither side of the Waianae-Koolau unconformity.The objective of the geophysical survey in the West Beacharea was to map the depth to the fresh-salt water interface.IIIIIIIIII(West Beach area) .1
he TDEM survey was accomplished by a four man crewconsisting of two BGI personnel and two local temporary fi ldhelpers.The location of the geophysical survey lines andsoundings were determined during consultation with EPWDC andtheir consultants.Initially, TDEM soundings were made along aeast-west line near the existing wells east of Honouliuli Gulch.These measurements were made near the 4 00 ft elevation forcorrelation with well data.The survey lines and loop locationsof the TDEM soundings for the Central Aquifer and West BeachSoundingareas are shown on Figures 2-1 and 2-2, respectively.locations were surveyed using a compass and hip-chain from knownroad junctions located on the field map.During the nine days of field work a total of 24 soundingsA daily log of fieldwere acquired over the two areas.activities is given in Table 2-1. ·In the Central Aquifer area, often two measurements weremade at each location to resolve both the shallow thinunconformity, as well as the deep saline water interface.Thiswas accomplished by using large (up to 1,500 ft by 1,500 ft)transmitter loops on 13 of the soundings, and smaller (400 ft to600 ft) transmitter loops on 7 of the soundings.Loop sizesvaried according to coverage needed on survey lines and availableproperty and road access.In the West Beach area four soundings were taken withtransmitter loop sizes of 4 00 ft by 4 00 ft.After the third day of the TDEM survey in the CentralAquifer area, access restrictions were placed upon the field crewby the landowner.These restrictions were as follows:1.TDEM data could not be taken east of Kunia Road due toyoung sugar cane growth.2.TDEM data taken south of Line 2N could only be acquiredin open (fallow fields) or after 3:30 p.m. when sugarcane employees had completed their work.day.3The TDEM crew could not work later than 4 :30 p.m. inthe sugar cane fields for Security reasons. '·,.,.·. .Because of these restrictions, productivity and opti.fimmstation density were somewhat.limited.The Geonics EM-37 TDEM system was uttlized on this survey.This system records the decay of. the vertiCal magnetic fieldthrough a receiver coil placed at the center of the non.;grounded·2 .
IItransmitterandII1,000mDuring data2loop.Receiver coils with effective areaswereutilized at base frequencies ofwith the receiverseveral receiverfor each sounding.gains with oppositeHz and30m2Hz.sounding location.state data logger,Readings were acquired atreceiver polaritiesThe readings were stored in a DAS-54which were nightly transferred to acomputer for processing.IIIIIIIIIIIII100acquisition numerous transient decays are collectedII3of3for eachsolidCompaq
LEGEND11WDSounding loop location'01WeU Locationsand Number (2303-0 1) .x:. - .!. !!:.: ,,t200002000SCALE- FEET/\BLACKHAWK GEOSCIENCES,INC.GEOPHYSICAL SURVEY. , .LOCATION MAPEwa Plains Water Dev. Corp.Central Aquifer Oahu, HIPROJI;CT NO.: 80008FIGURE 2-1
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1.'·I15a·og·.21"'22'30"III:'i.,236JOOOm.N.II. ;II.I1WDI.,,III ( ). . ·.*:.Sounding Loop Locationw,eu Locations·Hydrostatic Head (feet)·.I. ' i1 .;-:. ','.\\} \ ::-;::··. .20000.'--!!!,,,,. . ": .'· ·.:-.·. ·::.,:·., .:··SCALE - FlEET\'.:.·;.2000 i .\\]\;f)·, .:·::··J . -. ;.,c ral ·.,.,··-./\BLACKHAWK GEOSCIENCES,INC.GEOPHYSICAL SURVEY.LOCATION MAP.Etllia Plains Water Dev. Corp.West Beach, Oahu, HI·FIGUREPROJECT NO.: 800062-2
IIITable 2-1.Date(1990)Daily log of field activitiesActivityMarch 11Mobilization from Denver,IMarch 12Meeting with personnel from Campbell EstatesIMarch 13Meeting in A.M. with Oahu Sugar then beginwork in Central Aquifer area.Soundings lNlEand 1N2E.March 14Soundings 1N3N,Aquifer.March 15Soundings 1N5E, 1N6E in Central Aquifer.Asked by Oahu Sugar to stop work.Move . to.IIIIIIIIIIcoto Honolulu,HI.and finish mobilization.1N4E and lNlW in CentralWest Beach Area.March 16Meeting in A.M.Sounding lW.at Oahu Sugar.work restrictions in Sugar Cane· .,· · . ,· '.DiscussedFields.Soundings 2W and 3W and West Beach Area.Meeting in afternoon with Del Monte.March 17Central Aquifer soundings 1N6E,1N7E,1N8Eand 1N10E.March 18Central Aquifer soundings 2N1W,2N2Wand2N3W.March 19Central Aquifer soundings 2N4W,.2N6W.MarchWest Beach Area sounding 4W and CentralAquifer sounding 2N7W.202N5W andMarch 21Central Aquifer soundings 1N9E and 3N1W.March 22Demobili e equipment and personnel. ·. - :i, -IIII·- ·' 4". . . . .
IIIIIIIIIIIIIIIIIII3.0DATA PROCESSINGThe field data acquired each day was transferred from theDAS-54 data logger to a Compaq computer.The data for eachsounding location is edited and combined (both 3Hz and 30 Hzfrequencies) to produce a transient decay curve.This decaycurve is transformed into an apparent resistivity curve, which isentered into an Automatic Ridge Regression Transient InversionProgram (ARRTI).From the apparent resistivity curve a one dimensional model of resistivities and thicknesses is calculated.The inversion program requires an initial estimate of thegeoelectric section, including the number of layers, and theresistivities and thicknesses of each of the layers.The programthen adjusts these parameters so that the model curve convergesto best fit the curve formed by the field data set.Theinversion program does not change the total number of layerswithin the model, but allows all other parameters to floatfreely.···.··In general, field data quality throughout the survey sitewas excellent, although several soundings (2N1W, 2N7W and 3N1W)near major power lines were effected by excessive 60-cycle noise.The apparent resistivity curves and data sheets for allsoundings are contained in Attachment A.,"·
IIIIIIIIIIIIIIIIIII4.04.1INTERPRETATION RESULTSGENERALThe results of the interpretation of individual soundings isthe resistivity layering as a function of depth.Where soundingsare acquired reasonably close together then results of individualsoundings can be plotted to form a geoelectric section along aline.Two geoelectric sections were constructed from soundingsin the Central Aquifer area, and one geoelectric section was madefrom soundings in the West Beach area.To infer from the geoelectric sections geologic andgeohydrologic information, characteristic ranges of resistivitiesare assigned to known local geologic and geohydrologic units.The assigned resistivity ranges for the various units encounteredin the survey area are shown in Figure 4-1.An overlap occursThe most extensive overlapbetween the resistivity ranges.e.ccurs between the Glay soils or weathered volcanics and the'dryunweathered or fresh-brackish water saturated volcanics.sincethick clay soils or weathered volcanics occur mainly at thesurface, these two units can often be separated by their depth ofoccurrence in the section.The resistivity of the layer at theunconformity appears to fall in the same range as the clay soilsand weathered volcanics.In general, it is difficult to distinguish between freshwater saturated volcanics and brackish water ( 500 ppmchlorides) saturated volcanics by resistivity interpretation.The reasons for this are that in addition to salinity, changes inlithology and porosity also influence formation resistivity.In both survey areas the lower boundary of the fresh brackish water lens was interpreted to be terminated by the basalsalt water interface rather than impermeable rock.From theinterpreted depth to the salt water interface the amount of headand thickness of the fresh - brackish water lens can becalculated using the Ghyben-Herzberg Principle.This principlestates that for every foot of fresh water above sea level therewill be about forty feet of fresh water below sea level.Anillustration of the Ghyben "erzberg Principle is given iri Figu 4-2.4.2GEOELECTRIC CROSS-SECTIONS/CENTRAL AQUIFER AREA:·!,· "Line 1 NorthThe geoelectric section for Line 1N is shown in Figure 4 3.In the geoelectric section the unconformity between the Koolauand Waianae la:va flo'Ws was detected in soundings 1N9E, lNiE, . 1 N 2Eand 1N3E.From the geoelectric section an apparent dip for the·6.··· '::;:.-
IIIIII'?IS owards the east is derived.unconformity of approximate! 50 At sounding lNlW the upperrno yer is also interpreted as theunconformity, rather than surficial soils, because it is thickerthan would be expected for. soils, and it correlates with theapparent dip of the unconformity derived from soundings east ofHonouliuli Gulch.At sounding 1N4E the conductive layer at-520 ft depth is undetermined, because it coincides with thedepth of salt water.The depth to salt water saturated volcanics varies betweenelevation -520 ft at 1N4E to about -785 ft at 1N9E.Theelevation of the fresh-brackish water head derived from theTheGhyben-Herzberg relationship is also shown on the figure.upward undulation of the salt water interface interpreted atsoundings 1N1E and 1N2E and the low resistivity of the volcanicsbelow the unconformity could possibly be caused by upconing ofsalts due to pumping of the wells.·IIIIIIIIIIIIIWells in Honoulfuli Gulch and near soundings 1N1E and iN 2 E(Fig. 2-1) encountered water at static heads of 17 ft (personalcommunication with Torn Nance, 04/90).The head calculated forsoundings in the vicinity of these wells ranges from 14.7 ft to19.8 ft.This difference between head calculated from TDEMsoundings and that measured in the boreholes is withininterpretational error limits.A comparison of the TDEM sounding results from sounding 1N1Eand the geologic log from well 2303-01 is given in Figure 4-4.The results of the TDEM soundings are given in two formats on theleft, (i) as a depth-resistivity log, and (ii) in terms ofgeohydrologic units using the classification shown on Figure4.:1 .On the right side of the figure the condensed geologic logfrom well 2303-1 is shown.Good correlation between the TDEMinterpretation and major geologic units is observed.Theunconformity from the geologic log is found between 379 and 485ft in depth.In the TDEM interpretation the unconformity andzone of increased weathering above the unconformity have been. interpreted as one conductive layer with a resistivity of 20 ohmm and a thickness of about 225 ft.·Line 2 North., .The results of the geoelectric cross-section for Line 2N a.teshown in Figure 4-5.The sounding locaticmS! are shown in Figure.2-1.All soundings show, .a thick upper (::::: 125 ft 'to · 300 ft) . conductive zone interpreted as soils. andfor weathered volcanics.Along this section the layer at the unconformity between -theWaianae and Koolau lava flows was not detected, except possibiyat 2N1W.The sound;i.n.gs she\ { the. fresh-sC11ine int:erface to bedeeper on the west side of .the section. with. a. distinct r];se,, ctowards the eastern side.Sounding 2N1W shows a conductive layer·.·.·.· 7. . ,'.·.''
I ·. .·.: ·IIIIIIIIIIIIIII(15 ohm-m) at a depth of approximately 520 ft (about 150 ft abovesea level).This layer is interpreted as a zone of weatheredThis soundingvolcanics or possibly a layer at the unconformity.was taken near the Kunia Road where several power lines arelocated whichmay have distorted the decay curve at laterAdditional soundings on the east side ofmeasuring time gates.Kunia Road would help to confirm the extent of this layer.Contour MapIn the Central Aquifer area TDEM data are mainlyconcentrated along two profiles, because the TDEM crew was deniedaccess to most of the area between the two profiles.In order to incorporate the soundings located between thetwo profiles (1N10E, 3N1W, 3N7W) into one data s t a contour mapof the results of all of the soundings in the Central Aquifer .area was constructed (Fig. 4-6).In this figfire the elev tion ofthe top of the salt water interface derived from the TDEMmeasurements is contoured.These values are approximately equalto the thickness of the fresh-brackish water lens.Also shown onthis figure are the values for hydrostatic head calculated fromthe depth to saline water using the Ghyben-Herzberg Principle.In addition to the TDEM data, water level information from twowells along the H-1 freeway was also incorporated into thecontour map (information furnished by Nance, 1990, personalcommunication)., .are:Two main features are evident in the contour map.The decreasing hydrostatic head towards the area nearsounding 3N1W.2 The roughly semi-circular pattern of equal hydrostatichead in the study area.Previous estimates of fresh water hydrostatic head by Daleand Takasaki- (1976) in the Central Aquifer area show the hea tosmoothly decrease towards the south away from the Schofield high level aquifer (Fig. 4-7).This map shows the contours of equalhydrostatic head to be oriented in a west to east pattern.The.apparent discrepancy between the contours derived by Dale andTakasaki, and the TDEM data, is likely due to low data densityavailabl to construct the contour map of Dale and Takasaki.,.· ·.'. '·IIThese1.II·8 -: .· .·.,:
IIIIIII4.3GEOELECTRIC CROSS-SECTION/WEST BEACH AREALine 1 NorthFour TDEM soundings were acquired at the West Beach area asshown in Figure 2-2.The results of the geoelectric cross section for Line 1N near West Beach are shown in Figure 4-8.Thesection shows an upper conductive zone interpreted as clay soilsor weathered volcanics above sea level.The west portion of theline (soundings WB3W and WB2W) shows the fresh water - salt waterinterface to be very high in the section (about 100 ft below seaThe fresh-salt water interface drops rapidly towards thelevel).The rapid changeeast in the section to about -800 ft at WB1W.in depth to saline water between WB2W and WB4W infers some typeof ground water damming is likely at or near the ridge betweensoundings WB2W and WB4W.The calculated head levels at WB3W (2.3ft) and WB1W (20.3 ft) show excellent agreement with known waterwell data in the area (personal communication with Tom N nce,1990). IIIIII· · · ··· .II. . ·,c·I. .I··:::·I··,,. .I'· - :. .:. .-
-· --- 1 3; -- -- ----: -- --- -- - .,. -:- -Dry Unweatheredor 'Fresh-Brackish.·!·.i.: ;.a;;it 1·M ;,.cw. . :::::::.i.:t' ; ;,.c1:::::wii.i.:t':: ·s. ar. . . . .; ;;t;:u:r.a au. . »":u \.IDI:QJJ :vr.a:.:c . ··············· ······· ····· ····-·······-:.:. .::; ; :·:·.::. :·:::.:·i :::;;·: } : - ::;.·::: :.: ;.:.: :: ::( : ;:.: ::.:. ::: ::: ; :Sa.-Jt-. w t r . . . .···: ·. · :· · . , · : .,·:·.a. : . ,· n w. 4##. : f.Y * . J:?y· '.10·tRESISTIVITY1000100(Ohm-m)"'' 1\BILACKHAWK GEOSCIENCES, INC.I .T . . . CHARACTERISTIC'i \·1 :;-; , . I . :: ;·:.iRESISTIVITY RAN.GES.Ewa Plafns Water De'v. Corp.; PROJECT NO.: 90008FIGURE 4-1
--·----. .·: .·, ::' ··'Water Table. - · . . : . . .Sea· Lev.,l""'··--.·. --------.---:J:F; " Water.:;,. .-·--.----. .,.,. .,.,.Sea Watert 1/40 (h):;·:'v/\BLACKHAWK GEOSCIENCES, INC.;\,·:.'.!···.''FR(, J :Htiftz.aE·R G; , ·· ltlustration ol the·Ghyben-Herzberg P rlncipleEwa Plains. WtJter Dev. Corp .::PROtJECT NO.:. 10008 .·'·FIGURE4-2
"IWESTII.9eooC')0C') ,,ILl ''::;2, 0z0%400.EAST.%CJ,: ·e11N1·E 9C')0C') ,LEGEND,rw ,1N2E11N4E.1N3E 200I327394z:01- ( w wi(H.9 1·9.:.!!L············ - : ·· ·:· : :· : :· ···· ····· ·:·········· ··········· ; : - T · nT : , n: . · : , - i i - : ;;- i ; : .; i -i ; : :;-; i. .;-:: . .- .: ··-· · ···· ···········:······:·····- : : :···· ···· · ········-················ ·····················0- - ·g (16.7)- - !! . ;:- .:. .;·n:; ·t······· ,il,l\!1,\1 \l \' ',\I \,l l l l l \l\1\l r'l,l l l i\l l@l l l \1\l '\I !'ri':'l,ii ·in:i,;;:,: :.:?. . r :!mr,: :I1Iil.::::·::::- ,·::::·::::::-:::·::: ::: :·:·:·:·:::::: ::: :·::::: :::·::::·::· :: ::: ::: ::::·:::t::::: : :::::·::::::::: : :. t: : :.:::.: :·::.:::::: :.·::: .-200,, ,, :: ,,i mt!!:!I!!!ti:: :i: i::I: iit::::: i m::: ii :::::!::iii : ; r::. !!:::r: i i::::i!til: !l!!:! !iii i 1 i!iii!iH1r1:: ::: , ;;; , ., i: i i: i!if!: t!!! iilil: m: i i!t!!lll![ii:i lii!ll:! ::::.1 ::mil i tit!:: l:::::il!i!li:;r:ttll! i lili!: !timflli!l! llilii1 liJ!: ii::: ir:'i· . . ,O . . o . . . o o . . . o.p . o . . : . o o ooooo "'· "-400ifif;!f«.\ ;j ,!r ;;,;;;l' : ,f: !'!Il 'I I',',Il {Yi'!il 'il 't i ilit!l I'l,l'!1ll ti!!l1lilillli,l! l, 'li,sllfllii'!,[i![l,IilIi!'i1![1[i,iI,illl!!I!1' !1 1\!\1'!!1!!!!!!1 1 ,1,1 1'1 1 1 ,[,!'!;'D i;d;J. mllIl: :::::111::: i: !0ii :::, i;;f':'i:{;; ;g:m1l\:!.l J.:,: : : : :.: : : : ril 11:m··· · ······ · ···· ·· ····· ·········· ············· ····· ···· ···· · ·····: : ···· ·· :·'(, 7)Hydrostatic Head (feet) of Fresh Brackish Water Lens calculatedfrom Ghyben-Herzberg principleu306-!Values in Ohm-m. 188Q)Q)-100 :;: :::::::Sea Le·ve./(12.9)?D ·' .Clay Soils or We llthered Volcanics. Dry Unweathered VolcanicsUnconformity between theWaiana and Koolau lava flOW .Fresh-Brackish WaterSaturated Volcanics -. Salt Water Saturated Volcanics - .·Salt Water Saturated Volcanicsor Unconformity.,1000:· 01000. SCALE - FEETJ\BucKHAWK GEOSCIENcEs, ONe .CROSS SECTION LINE 1 NORTH: ,;Ewa Plain Water .Dev Corp.-Central Aquifer Oahu, HIPROJECT NO.: 80006FIGURE 4-3 .
- ----------- ------TDIEM Sounding IReaults 1 N 1 E(elv. 380 feet)Drilling ResultsDepthGeoelectric InterpretationHydrologicDepth(ft)(computed static head 15 ft)Interpretation(ft)Geologic Log of Upper HonouliuliWell #2303-01(elev.400 ft)(static head 17 ft)0 .,[IIsoilIIDry Unweatheredlla-soRed clay,50-225Mixture of Pahoehoe and aa fresh dark greyVolcanicsaa,loose cindery red mudwith large cuttings of dense Pahoehoe200225-379-1Unconformity379-485400-00e-Red mud and compacted clay (379-415')unconformity from geologic log.)(Increased weathering, med grey Pahoehoemixture of reddish-brown and grey aa485-TD"'}-6002-Fresh-Brackishgrey PahoehoeWater Saturated-1 Volcanics.j.&:. Cl.cucMixture of reddish aa dark grey aa,TO 625'1-BOO.3- -------Salt WaterSaturatedVolcanics.4I11200II I 8 I I I ldD0 I t DO Ill10RESISTIVITYdI I 111011100(Ohm-m)1000/\BLACKHAWK GEOSCIENCES,INC.COMPARISON OF SOUNDING 1 N 1 EAND GEOLOGIC LOG WELL 2303-01Ewa Plains Water Dev. Corp.Central Aquifer, Oahu, HIPROJECT NO.: 90006FIGURE 4-4
I WESTIEAST'8000(Possible distorted800II .:. :- !- - -: - :- - - -:: - readings due to powerllnes%u.-near Kunia road.) 2N4W2N5WC:.' .------------ -------800-- --II·0 ----.;. . . .: I' " . )Dffiil. lil'."1.," '. . ,. ;. ,.,. c c'- . 15 . . '1 'i f . ,. 1'1 &. A ,.Clay Soils or Weathered Volcanics."''""" .Level.1C16.1), : . " (4.2 ? . .,: Sea(9.7)//. 7:. .,---- ---i . .- -- -- . C16.4) · : : :f ; : : : : ; :{ - I · · - } - : - - T T - . · T . U.n i n: '::·:::· ::· :· :::· :· :::· :·:::·:·:::::::::·::::::: ::::::: :::::: :::::: ::: :·:;::::::::::: :::::t:.:.:.:.:.: ::: :·::::: : ::: : : ::::::: :::::::.::: ::· ::;::: :· ; ::.:;::- :::.::: :·::: ::: : ::. :. : :::: : ::::::::· ::: :::: :. : . : : :::::::::: -;. :.:·:·:::::: :: :: ::::.:::::::.:.::::: :::. :.: : :.::::· :: :·:.: : :·: : ::::::·::. ::::::::· :::·:: : : :-: ::::::· ::: .::- ::::: !::- �:::::·:·:::::·:·:·-:::::·:::::-::: :·:::::. :· :: ::::::::::::::;:;::::::.::: :::· ::::::; ::::-: ::::.:,::::::::.:::::::-:-::::::-::::::::::.:,:· :::·: : :. ::::::::·:::::-::-::::- :::::::::::·:.: :: ::::- ::- ::::::. ::·:·:::::::::-::::-:·::::::·::::::::::::· -::::::·:::::·:·:·::::::::: :· :::::::::. .,7 88'472248: Dry Unweathered Volcanics.Fresh-Brackish WaterSaturated VolcanicsSalt Water Saturated Volcanics:Weathered Volcanics orUnconformity:wJw···········- ····· ··········· . . : : :··· · · ···: :· ························ · ··· ···· · ········. .-. . . . . . . . . . .:.: : . : : :······:······: .:.··. .tttt.: . . : : : �···· ·····. . . . . . . . . . . . . .: : : : : : : . ····: ··········:····;··· .,.I e e:e;e : : e e: e e:e.e:a ee. . . e ,e, e . · e.ae.·. . . . . . . . . . . .: . ············ : . .·I··. . �··· ······ ··· : . : : : . :. - .·······. :. -.-. : : ·········: : : : · ········: · ··············· lltl ::::::: : :: :::::::· \ ::: ll:· ::: l :1:::\r r ·:·::::::· · t ; l } :· ·::::· t :·: :·::·: ::::::: r ·:· .::· :-::::::::::::::l:::: :: \:. t:::- :- :·:. m:::: ::-: :::·:.:·:·:1 1 :::::::::::.:.:::·:::·:::::::· :::::::II.--::::: : :.:.-: : : :.:.: : :':.:.: : : :. : :::.: : : ! : .:-:.: i : :.:.:;: : : :;:.: : : ::::::: : : :.:.::::: : : : :.::: : :: ::::':::::::: : ::: � ·······: · ·· · : : : ···· : · ······· ····· : : · ········: : · ·················:····· ··. : : . ············::·· ···· ····················· ·· · : : : ·········· ···· · ··· ··: : · · ········:······· ···· . : : ······ : : : ··············· !.·.!················· ···.:::::::;:;:':-: :;: :. :· : : : :: .::: :.:;·:;:::;: : : :; : .:.: ': : : : ::: .: : ::: :: :.::': :· ::':::: :::.::':: :: :- .:: :: ::: : ::· ::::':.:: :::::- :-: :.:::::::: : ::.:·:::::-::::::t::·:::· :::::: :·:. :::·: :;::::·:::::::::·:.:::::::.:· ;:::::. ::-.:::: :. :· ::, :· :· ::-::. ::::-· :·:::· ·:::·:::::::-:·::· ::: ,:·::- ::::;· ::- � :::::::::::.:::::::;::::. :::·:::::::::::::::::::: :::::·::::·:::-:::: : : :· ::·::·: ::: :,:.:::::·:·:::::: :. :;::::·::::·:·::·:; ;:·:::::::::·:::::·::· :::::I.01000.·. :.: . - .- . !' - . . . ···· : : . , : · · : ·: ·: .:!:-::::;,;.600I. III·,,""'·· .,200(17.9)·173-.,.-.,.'. 207. ) of Fresh Hydrostatic Head (feetBrackish Water (ens calculatedfrom Ghyben-Herzberg principle · I(l)(l)---""". ,-Values in Ohm-m07)-- '-' 400z01 (100------------------------------- --- ----IalIf - 03E ;e} - E:f E -f : E E 3 3E i-t :-------------- -----------II -- : :r [ ---------- -LEGEND2N'8W1::::: 11 t!:! . ! !!iii : ::I: mmi :: : : ::1;:::t:::f: :.:: :J.mJm!::::J:::; : t:.t?/\BLACKHAWK GEOSCIENCES, INC.···· · ······ ·····.". ·.CROSS SECTION LINE 2 NORTH.Ewa Plains Water Dev. Corp··-aoo'I Central Aquifer Oahu, HIPROJECT NO.: 80006FIGURE 4-5 .
:,IIIi'j'',-!III'I·· .,./LEGEND1WD'. !Sounding Loop Location01. Well Lo.cations ;·and ·Number (2303-0 1:).,)'-600i'I(15)l·"j'·.Hydrostatic Head (fee.t) ofFresh-Brackish Water Lenscalculated from Ghyben - Eh: vation of Top ofSalt Water InterfaceHerzberg· 'Principle.200020000SCALE"" FEET/\BLACKHAWK GEOSCIENCIES,·IliI·!!II1'1'I,I·TDEM Survey Contour MapTop of Salt Water interfaceE.wa Plains WaterINC.·Dev. Corp.Central Aquifer Oahu, HIPROJECT NO.; 90006FIGURE 4-6
--- ----------- se·ooI.:-- l Ilr-j\\\\ \ \.\ \\ \ \\ \ '\ \. '-,. '\\ ' .\'37-,- \ ,,.-,] '--: ''-r ' ''. .,.;.-I'.A,. -\ '\ ''{ ,I ;,- ,/\''\ ., . ''""·.- 'I./ .\)'-'\'\.' - / A . . /. .\' II·-. ''\'v,./r ,::-./\ \o.'I85270\\., i'\\ \· '\o\.---,o\c;L.: go--. ---- ---- ' . \ ;\-3,*-7/"' \-,1-\(c',.\.\'--,-· o -il oS· I\i.y!,}- .;, . ,.CO·.," .·----tsr s· '--j 1''oOAHUi 1 :, if I ;01Il f""" nt "01o I 'II PEXPLAN TI N--7.3- Freshwater-head contour in metresContour interval 0.3 metresDatum· is mean sea level-270Average value.of freshwater head-at a point lo "MlThl'-lim it of .flo in the PearlSc o iclrlHarber area that-is rechargedfro;-; thewater body21"30---·-- -''·;·-- OUTliNE OFSURVEY AREA AS '\.', ,,t-SHOWN DN FIG. 2-1·,';i )) \ L. 6"'-'- -.;. -,,,1·1IIII-'-e 151ss-oo·- - . · , . ,. '-. -. .1I----12 I15./\BLACKHAWK GEOSCIENCES,'-1·r-'·"u :.· .ala s k I. ·USGS ·water-Resources.76-41 . May, ,1976, lnvesttgatlon, MF' . .' ,'. ri- 't k a:. ' .INC.FRESHWATER-HEAD MAPEwa Plains Water Dev. Corp.Central Aquifer, Oahu, HI. PROJECT NO.: 90006FIGURE 4-7 .
iIIEASTWESTIIw ·c J0400i.a:200-Q)Q)·-.Q!: I cyWB4W iE : E ; : ; . . ' Values in Ohm-m100I(17)'!!a.:!.:::::: ::: :: : : :: : :: : : : ::::: : : : :: : :::::::::2:;::: j ::::::::::::::mr:;::::.:m:i:·l.l.l!l.[!.·lJl.1J: ·t:!. -ll!]i.:::l1 J.t.!,\·1 0LEGENDc- . : ""'".:-- -: 2 i) - ----- - - - -- - ----- --:ra-2F---- --- --- ----- ---: 11.5 ----- -- -.:-- --- -iio 9 -:---: --:.- :- -:-.:- - -.;;.;;:: . . .i7i77.0 .-:-. . . . . -:::;: :-:-.:: ::-: ::-.::.:.-:: ;:-.--:-;,-;-; ;::.:- - - :::;.;:; ::-.;:;.---- - ::- .-:.: tuJw!c J - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ziWB2W.,. e. 'WB3W.X(.)X(.).SeaLevel §3[].-200 . Hydrostatic Head. (feet) of FJesh Brackish Water Lens calculatedfrom Ghyben-Herzberg principleClay Soils or Weathered VolcanicsDry Unweathered VolcanicsFresh-Brack·ish Wate.rSaturated Volcanics,I1B].-400.Salt Water Saturated Volcanics--800I'·.,· ···- aoor.5000500------------ ---·seALE- FEET·--- . · - . -1000'/\BLACKHAWK GEOSCIENCES,I. ""--.,., :·.-CROSS SECTION LINE 1 NORTH. · .· Ewa ·P,alns. Water Dev. Corp.};INC. . West :B,sch, Oahu, HIPROJECT NO.:80006FIGURE 4-8,j
IIIIIIIIIIIII5.0CONCLUSIONSThe results of TDEM soundings taken in the Central Aquiferarea
2.0 LOGISTICS AND DATA ACQUISITION The TDEM survey was accomplished by a four man crew consisting of two BGI personnel and two local temporary fi ld helpers. The location of the geophysical survey lines and soundings were determined during consultation with EPWDC and their consultants. Initially, TDEM soundings were made along a
*Cambrian-Ordovician aquifer St. Lawrence aquifer Jordan sandstone aquifer Dresbach aquifer Two Important Aquifer Characteristics 1. to store ground water, and 2. to transmit water to well. Transmissivity: measure of how easily water moves through an aquifer. Similar to K, but applies over the thickness of a given layer in the aquifer. T i b iK i
BN-77L BN-77V BN-82E BN-82F BN-82K 453312098244401 AREAL EXTENT OF THE ELM AQUIFER (modified from Benson, 1997; Hamilton, 1982; Koch and Bradford, 1976) EXPLANATION AQUIFER TEST AREA WELL COMPLETED IN ELM AQUIFER--Number is well identification number ELM AQUIFER WELL WHERE WATER-LEVEL DATA WERE COLLECTED DURING THE AQUIFER TEST--Letter is
The surficial aquifer is an unconfined aquifer system that overlies the intermediate aquifer system and ranges from a few feet to over 60 feet in thickness in the study area. Hydraulic properties of the surficial aquifer system determined from aquifer and laboratory tests, and m
Bruksanvisning för bilstereo . Bruksanvisning for bilstereo . Instrukcja obsługi samochodowego odtwarzacza stereo . Operating Instructions for Car Stereo . 610-104 . SV . Bruksanvisning i original
feet to more than 600 feet deep. The Aquifer covers 321 square miles. The total flow of the Aquifer is estimated at 390 cubic feet per second at the Idaho-Wash- . Aquifer Spokesman-Review, Thursday, May 6, 1909. 2 Aquifer
Aquifer characteristics used in the models include transmissivity of the confined and unconfined portions of the surficial aquifer system and the Upper Floridan aquifer, leakance of the semiconfining unit of the surficial aquifer system and of the upper confining unit, and evapotr
Aquifer characteristics used in the models include transmissivity of the confined and unconfined portions of the surficial aquifer system and the Upper Floridan aquifer, leakance of the semiconfining unit of the surficial aquifer system and of the upper confining unit, and th
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