Hydrogeologic Cross Sections, Plate 9, Groundwater Atlas ......Mississippi River (Grey Cloud Slough)...
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1050 1100 1000 950 900 850 800 750 700 650 600 550 500 450 1050 1100 1000 950 900 850 800 750 700 650 600 550 500 450 400 350 300 250 200 150 400 350 300 250 200 150 Elevation (feet) J’ J Lake St. Croix Beach CSAH13 St. Croix River CSAH19 Aſton MN95 N. Fork Valley Branch Creek CSAH21 Woodbury I494 CSAH18 Powers Lake CSAH16 ss _m Cw _e _m r3 _sl ss _e ss _w _tc lower _m qu _e _w _tc _tc ss cr se ce ss se Opg ce ss ss pt ce r1 Os ce r1 Ops sv _j cr s2 r2 _j Opo Opg Ops Od _sl vt ce Os qu r3 _tc lower _j r2 r3 xt 2500 1800 53.1 28.8 22.1 47.8 14.4 19.9 39.7 27.5 32.4 17.9 14.8 75 12.7 760 800 840 680 720 6 6.8 1.3 1.2 2.2 9.1 2.6 1.51 3.03 5.4 sc sc sc 1050 1100 1000 950 900 850 800 750 700 650 600 550 500 450 1050 1100 1000 950 900 850 800 750 700 650 600 550 500 450 400 350 300 250 200 400 350 300 250 200 Elevation (feet) I’ I I694 MN95 St. Croix River Lake Elmo CSAH15 Eagle Point Lake CSAH17 CSAH13 CSAH21 r3 sp _j _j _tc _e _e _m r3 Os qu Opg qu se cr cr ce ce pt ce se Os ce ce se cr cr cr vt Os Ops r1 ce _w _m _tc lower _sl Os Ops Ops Ops Opo Opo r2 2000 325 69.5 680 720 760 800 840 880 1.12 2.3 E sc 1050 1100 1000 950 900 850 800 750 700 650 600 550 500 450 1050 1100 1000 950 900 850 800 750 700 650 600 550 500 450 400 350 300 250 200 400 350 300 250 200 Elevation (feet) H’ H CSAH21 I694 CSAH15 Oakdale CSAH17 Sunfish Lake St. Croix River Washington Co landfill CSAH13 ce Os cr _tc r1 ce Od cr cr cr ss ce ce r2 Os ce r3 pt r1 Opg cr qu r1 cr Os r2 sl Opo qu _e _m cr _tc Ops Opo Ops r1 cr r3 cr r3 cr r2 r3 _j _j _sl _tc lower _w cr pt ce ce cr ss ce <100 14.8 + 27.6 15.8 900 880 860 840 800 760 720 680 E sc sc LOCATION DIAGRAM 1 0 1 2 3 4 5 MILES 1 0 1 2 4 5 6 7 8 3 9 KILOMETERS SCALE 1:100 000 VERTICAL EXAGGERATION X 50 Quaternary aquitards Grouped by texture ranging from highest to lowest sand content indicang relave hydraulic conducvity. Geologic unit code Percent sand ce, cr, r1, sl r3, vt r2, xt pt >60% >50% and ≤60% >40% and ≤50% >30% and ≤40% Groundwater condions Symbols and labels Land or bedrock surface General groundwater flow direcon Geologic contact Approximate geologic contact Approximate equipotenal contour; contour intervals 20 and 40 feet 800 Water table Trium age Darker color in small vercal rectangle (well screen symbol) indicates trium age of water sampled in well. Lighter color indicates interpreted age of water in aquifer. Mixed: water is a mixture of recent and vintage waters (greater than 1 TU to less than 8 TU). Well not sampled for trium. Vintage: water entered the ground before 1953 (less than or equal to 1 TU). Recent: water entered the ground since about 1953 (8 to 15 trium units [TU]). Chloride: if shown, concentraon is ≥5 ppm. (* naturally elevated, + source unknown) 32.4 Nitrate: if shown, concentraon is ≥1 ppm. 6.8 Arsenic: if shown, concentraon is ≥2 ppb. 2.19 Groundwater sample with evaporave signature Carbon-14 ( 14 C): esmated groundwater residence me in years. 2500 E Enhanced-permeability zone (see Report page 9) Groundwater moves from an overlying surficial aquifer to a buried aquifer. Trium concentraons may be arficially elevated by high capacity pumping. Groundwater moves from an overlying buried aquifer to an underlying buried aquifer. Groundwater discharges to a surface-water body. Direcon of fault movement, arrows indicate relave movement Groundwater flows laterally. *aquitard *aquitard sc, sc1, sc2* sl* ss, ss1, ss2 cr* se ce* s1 r1* s2 r2* sx xt* s3 r3* sp pt* sv vt* su qu Aquifers and aquitards Quaternary unconsolidated See Figure 4 in the report for geologic unit correlaon. Bedrock Decorah Shale* Plaeville and Glenwood formaons St. Peter Shakopee Oneota Dolomite* Jordan St. Lawrence Formaon* Upper Tunnel City Lower Tunnel City* Wonewoc Eau Claire Formaon* Mt. Simon Cross Secon Explanaon Interpreted trium age is indicated by background color. Interpreted trium age is indicated by paern color. _tc lower _tc _sl _j Opo Ops Os Opg Od _w _e _m sc sc1 sc2 ss ss1 ss2 1000 950 900 850 800 750 700 650 600 550 500 450 1000 950 900 850 800 750 700 650 600 550 500 450 400 350 300 250 200 400 350 300 250 200 Elevation (feet) M’ M CSAH21 Mississippi River (Grey Cloud Slough) Coage Grove St. Croix River US61 MN95 Mississippi River Opo _j Opo _sl r2 _tc _tc _tc _tc r2 ce _j _j Opo pt _j Ops pt Ops Opo _tc lower _j Os Ops r3 _sl Opo _sl _m _sl _j _j pt qu _tc lower _w _sl _tc _sl _tc lower _tc lower _e _w _w _e _e _e _m _j Opo ce Opo 6500 7.88 15.8 8.45* 28.7 720 760 680 30 1.17 11.4 6.3 7.7 6.6 sc2 sc2 sc sc1 sc 1000 950 900 850 800 750 700 650 600 550 500 450 1000 950 900 850 800 750 700 650 600 550 500 450 400 350 300 250 400 350 300 250 Elevation (feet) L’ L US61 CSAH19 Mississippi River MN95 St. Paul Park CSAH21 Coage Grove St. Croix River pt _j r1 r1 Opo Os s1 Ops _j Ops _tc lower ce _e _e Opo _e _w _w Opo _e _tc lower Ops Ops _e ss Ops _e _m _w _w _w _sl ce _sl r1 pt ss1 sc pt _tc lower Os _j Os _sl _j _tc ss2 _tc _tc _tc _tc _tc _sl _tc _j _tc lower _tc lower Opo Opo r3 r1 _m _m _m _w _m _sl _sl _j Ops vt r2 sx Ops ce r2 ce 2500 <100 2000 25 32.7 25 51.6 33.7 34.2 18.9 14.8 31.4 680 720 680 760 720 760 800 840 2.33 2.78 2.09 2.19 2.8 1.9 6.4 12.1 5.3 1.6 3.1 sc sc1 sc2 1050 1000 950 900 850 800 750 700 650 600 550 500 450 1050 1000 950 900 850 800 750 700 650 600 550 500 450 400 350 300 400 350 300 Elevation (feet) K’ K CSAH19 Bailey Lake South St. Croix River MN95 North Branch Trout Brook (intermient) CSAH21 3M Woodbury Disposal Site US61 Mississippi River CSAH13 Newport r1 _j Opo Ops _w pt _e _tc lower _tc Opg Opo ss Od r1 ce Opg ce Ops _j Os ce vt Opo ss pt Opg ce Opo pt pt r1 Opg ss Os _sl _sl _j Ops Opo Ops _j Ctc Os _tc _j _tc lower r1 _m _m _w _m r2 _j Opo _w _e _sl _w _e _j _w Ops _j sc1 _tc lower _tc _sl _e _sl 2500 74.9 76.2 64.6 33.4 9.65 + 32.9 48.1 36.0 8.21 68.0 10.9 760 800 720 760 800 840 720 840 9.5 5.5 7.8 3.02 3 3.8 2.90 E E E sc Hydrogeologic Cross Secons By James A. Berg and J. Wes Rutelonis 2019 Groundwater Atlas of Washington County County Atlas Series C-39, Part B Plate 9 of 9 Hydrogeologic Cross Secons H–Hʹ through M–M ʹ Minnesota Department of Natural Resources County Atlas Program mndnr.gov/groundwatermapping To accompany atlas Report and Plates 7–8. Southern cross secons I–Iʹ, J–Jʹ, K–Kʹ, L–Lʹ, and M–Mʹ Explanaon of H–Hʹ is on Plate 8. See Report Figure 4 for associated geologic units. This group of cross secons is characterized by a thin layer of surficial sand and sandy ll (approximately 50 to 100 feet thick), shallow bedrock aquifers with likely karst-type porosity and permeability, a deep buried bedrock valley (200 to 250 feet), and faulted bedrock in the east. All of these factors contribute to deep penetraon of recent and mixed trium-age water that can range as deep as 600 feet with the combined effects of deep fractured bedrock from the buried bedrock valleys and lateral groundwater flow. The locaon of the main buried bedrock valley relave to the groundwater divide is a major control of the direcon of mixed trium-age groundwater flow in the Jordan (_j) and Upper Tunnel City (_tc) aquifers. On cross secon I–Iʹ, the buried valley lines up approximately with the groundwater divide in the Jordan aquifer. Mixed trium-age water was found on both sides of the buried valley. A similar trium distribuon is shown on J–Jʹ. Two carbon-14 age dates in the Jordan aquifer are shown on the western and eastern porons with values of 2,500 and 1,800 years respecvely, values typical of the Jordan aquifer in the southern part of the county. The eastern poron of I–Iʹ contains an unusual layering of residence me. Vintage trium-age water is found above mixed trium-age water in the Jordan aquifer. Pumping from the Upper Tunnel City and a naturally downward gradient may be drawing mixed trium-age water deeper than would be expected. Another notable feature is the evaporave signature from a shallow well downgradient from Lake Elmo, signifying lake discharge to groundwater. On the eastern side of cross secons K–Kʹ and L–Lʹ, all the bedrock aquifers were displaced upward by a horst structure, as much as 200 to 300 feet compared to areas west of the horst. On K–Kʹ, recent and mixed trium-age water was interpreted in the shallow Plaeville (Opg), St. Peter (Os), and Prairie du Chien aquifers (Ops and Opo). Evaporave signature water was found south of Bailey Lake in the Prairie du Chien aquifer (Ops) and overlying surficial aquifers. Just west of CSAH 13 for approximately 1.5 miles the Jordan aquifer apparently has some protecon from the deep (unfractured) condion of the Oneota (Opo) as indicated by the vintage trium- age water. Otherwise, the Jordan aquifer appears to get recharge water of mixed trium age from the buried bedrock valley at CSAH 19 and a shallower bedrock valley farther to the west (east of Newport). Farther west on K–Kʹ two Jordan aquifer groundwater samples contain mixed trium-age water where it might be expected to contain vintage trium-age water from upwelling of older water to the Mississippi River. These locaons could be evidence of pumping effects drawing mixed trium-age water deeper than would otherwise be expected. On the western poron of L–Lʹ similar residence me condions appear to exist within the St. Peter and Prairie du Chien aquifers (Ops), which are completely filled with recent and mixed trium-age water. Porons of the Jordan aquifer containing mixed trium-age water were sourced from the buried valley east of CSAH 19. A sample collected west of US 61 had recent trium age and a carbon-14 residence me of less than 100 years. These values seem anomalous in an otherwise mixed trium seng and may be influenced by high-capacity pumping or a leaky well casing. Further west on L–Lʹ (between St. Paul Park and the Mississippi River) a Jordan well contained vintage trium-age water possibly from upwelling of older water to the Mississippi River. The carbon-14 values of 2,000 and 2,500 years were typical of the Jordan aquifer in the southern part of the county. On cross secon M–Mʹ almost the enre Jordan aquifer is within 200 feet of the surface and probably contains recent and mixed trium-age water. The excepons are the far western and eastern porons that contain vintage trium-age water due to the upwelling of older water discharging to the Mississippi and St. Croix rivers. At four locaons, vintage trium-age samples from the Upper Tunnel City aquifer (_tc) and the Lower Tunnel City Group (_tc lower) appear protected by the St. Lawrence aquitard (_sl). These locaons include a site in Coage Grove and three sites east of MN 95. West of US 61 an Upper Tunnel City groundwater sample had an esmated carbon-14 age of 6,500 years. Two sites in the Jordan with mixed trium-age water are near and downgradient of faults that may have enhanced downward flow in these areas. These locaons include a site just east of US 61 and a site west of CSAH 21. This map was compiled and generated in a geographic informaon system. Digital data products are available from the DNR County Atlas Program at mndnr.gov/groundwatermapping. This map was prepared from publicly available informaon. Every reasonable effort has been made to ensure the accuracy of the factual data on which this map interpretaon is based. However, the DNR does not warrant the accuracy, completeness, or any implied uses of these data. Users may wish to verify crical informaon; sources include both the references in the report and informaon on file in the offices of the Minnesota Geological Survey and the DNR. Every effort has been made to ensure the interpretaon shown conforms to sound geologic and cartographic principles. This map should not be used to establish legal tle, boundaries, or locaons of improvements. Base modified from Minnesota Geological Survey, Washington County Geologic Atlas, Part A, 2016. Universal Transverse Mercator projecon, zone 15N, North American Datum of 1983. North American Vercal Datum of 1988. 500 Lafayee Road St. Paul, MN 55155-4025 888-646-6367 or 651-296-6157 mndnr.gov This informaon is available in alternave format on request. The Minnesota DNR prohibits discriminaon in its programs and services based on race, color, creed, religion, naonal origin, sex, public assistance status, age, sexual orientaon, or disability. Persons with disabilies may request reasonable modificaons to access or parcipate in DNR programs and services by contacng the DNR ADA Title II Coordinator at [email protected] or 651-259-6157. Discriminaon inquiries should be sent to Minnesota DNR, 500 Lafayee Road, St. Paul, MN 55155-4049; or Office of Civil Rights, U.S. Department of the Interior, 1849 C Street NW, Washington, DC 20240. © 2019, State of Minnesota, Department of Natural Resources and the Regents of the University of Minnesota Prepared and published with the support of the Minnesota Environment and Natural Resources Trust Fund and the Clean Water, Land and Legacy Amendment T. 32 N. T. 31 N. T. 30 N. T. 29 N. T. 28 N. T. 27 N. T. 26 N. R. 21 W. R. 20 W. 44° 52' 30" N. 44° 45' N. 45° N. 45° 07' 30" N. 45° 15' N. 92° 45' W. 92° 52' 30" W. 93° W. 61 36 10 10 61 8 694 ¦ 94 494 ) 95 ) 95 95 ¤ 61 97 244 ) 5 96 ¦ ) ) ) ) ) ¤ ¤ ¤ ¤ ¤ ¦ St Paul Park Newport Cottage Grove Woodbury Lakeland Shores Bayport Oak Park Heights Stillwater Marine On St. Croix Hugo Oakdale ¦ 35 Forest Lake RAMSEY COUNTY WASHINGTON COUNTY B D A C F E G I H K J L M E’ A’ C’ B’ D’ G’ F’ K’ I’ H’ J’ M’ L’ D’ E’ F’ F E B C B’ C’ D Symbols Part B line of cross secon shown on this plate Well used to generate cross secon* A A’ Part B line of cross secon shown on Plate 8 H H’ Part A line of cross secon B B’ 1 0 1 2 3 4 SCALE 1:300 000 1 01 2 4 5 6 7 8 3 9 KILOMETERS 5 MILES N *Not all wells are displayed in cross secon view due to the high density of wells. T. 32 N. T. 31 N. T. 30 N. T. 29 N. T. 28 N. T. 27 N. T. 26 N. R. 21 W. R. 20 W. 44° 52' 30" N. 44° 45' N. 45° N. 45° 07' 30" N. 45° 15' N. 92° 45' W. 92° 52' 30" W. 93° W. 61 36 10 10 61 8 694 ¦ 94 494 ) 95 ) 95 95 ¤ 61 97 244 ) 5 96 ¦ ) ) ) ) ) ¤ ¤ ¤ ¤ ¤ ¦ St Paul Park Newport Cottage Grove Woodbury Lakeland Shores Bayport Oak Park Heights Stillwater Marine On St. Croix Hugo Oakdale ¦ 35 Forest Lake RAMSEY COUNTY WASHINGTON COUNTY B D A C F E G I H K J L M E’ A’ C’ B’ D’ G’ F’ K’ I’ H’ J’ M’ L’ 5500 6500 2500 6000 3000 9000 2500 4000 2500 <100 2000 6500 1800 5500 25,000 2000 <100 2500 <100 <100 20,000 <100 1 0 1 2 3 4 SCALE 1:300 000 1 01 2 4 5 6 7 8 3 9 KILOMETERS 5 MILES Symbols and labels Carbon-14 ( 14 C): esmated groundwater residence me in years. 5500 Line of cross secon (Part B) B B ’ Sampled well and aquifer symbols Prairie du Chien Jordan, Jordan–St. Lawrence Tunnel City Wonewoc–Eau Claire Eau Claire Wonewoc–Mt. Simon, Mt. Simon, Mt. Simon–Hinckley N Cross secon locaons and wells used for cross secon generaon Carbon-14: esmated groundwater residence me in years
Transcript of Hydrogeologic Cross Sections, Plate 9, Groundwater Atlas ......Mississippi River (Grey Cloud Slough)...
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r2
r1
400014.4
25.1
61.6
45.09+
7.53
34.1
34.2
37.6+
13.1
119
15.8
75.6
880
920
880
720
680
760
800
840
2.58
1.110.8
2.03
3.05
E
sc
sc
sc
sc
1050
1100
1000
950
900
850
800
750
700
650
600
550
500
450
1050
1100
1000
950
900
850
800
750
700
650
600
550
500
450
400
350
300
250
400
350
300
250
Ele
vatio
n (fe
et)
F’F
Long
Lak
e
CSAH
15
Lily
Lak
e
CSAH
5
Stillw
ater
MN
95St
. Cro
ix R
iver
Was
hing
ton
Lake
CSAH
36
Sunn
ybro
ok L
ake
CSAH
17
r1
r3
r1ce
xt
ss
crss
r1 ce
cecr
cr
cr
cr
r1
r1
sl
ce
_e
_m
ss
r3 ptOs
_tc
_j
se
Ops
Opsr1 r1
cr
Os
r2
cr
Opo
sv
Opo
_j
vt
qu
_sl
Opg
_tc lower
ce
_w
pt slsl
20.116.5
14.614.8
7.69
25.5
58.2
920
720
76080
0
840
880
3.15 2.5
5.12.4
3.91
1.7E
sc
1050
1000
950
900
850
800
750
700
650
600
550
500
450
1050
1000
950
900
850
800
750
700
650
600
550
500
450
400
350
300
250
400
350
300
250
Ele
vatio
n (fe
et)
E’E
Whi
te B
ear L
ake
CSAH
9
MN
244
CSAH
5
Brow
n's C
reek
(floo
dpla
in)
MN
95St
. Cro
ix R
iver
CSAH
15
Mah
tom
edi
xt
qu
cecr
lc
sl
Ops
_j
ce
r1pt
ce
ce
vt xtvt
slse ce
OpsOpo
Os
_tc
r1
ss
Opo
cr
sl
r1
cr
pt
crcece
s2
r2
r2
r2
r3
r2
ce
_j
pt
qu
Os
vt
Os
_e
_m
_sl
_tc lower
r1
sc
r1
ss2
r1
qu
_w
su
ptss
pt
ntcr
ss
Os
14.6+
19.7
35.2
16.1
760800
840
880
920
900
720
3.70
2.03
E
sc
sc
sc
1050
1000
950
900
850
800
750
700
650
600
550
500
450
1050
1000
950
900
850
800
750
700
650
600
550
500
450
400
350
400
350
Ele
vatio
n (fe
et)
D’D
US6
1
CSAH
8
Bald
Eag
le L
ake CS
AH15
Suns
et L
ake
CSAH
11
Big
Carn
elia
n La
ke
MN
95
St. C
roix
Riv
er
_w
ce
_e
OpsOs
lc
crce
ceOs
r3 Opo
cr
r3
ss
lc
xt
_j
xt
_tc
_tc
ce
ptr3r3
ntce
xtlc
cr
r1 ce
sllc
r2 r1
cr
cer1
cr
ce
r1
Opo
cr
xt xt
r1lc
Os
_m
s3
ce
Os
_tc lower
xt
r2
r1
pt
_sl
r1Ops
r2
Ops
ce
r2
xt
ce
xtr3
8.52
6.02
66.021.9
11.0
70.115.4
80084
088
0920
960
720
880
760
10.5
8.5
2.72
E E
sc
sc
sc
sc
1050
1000
950
900
850
800
750
700
650
600
550
500
450
1050
1000
950
900
850
800
750
700
650
600
550
500
450
400
350
400
350
Ele
vatio
n (fe
et)
C’C
St. C
roix
Riv
er
Squa
re L
ake
MN
95
Rice
Lak
e
CSAH
17
Hugo
CSAH
15
Egg
Lake
_js3r2
Os
sllc sl
Ops
ss
lcsl
Ops
cr
r1
Ops
qu
_w
qu
sc
r3
OsOs
_sl
xt
Opo
lc
_tc lower
r3 _sl
ce
r2
ce
r1
cr
_sl
ce
r2
sese
cextxt
ce
crr3
ce
_m
_e
nt
ss xtr1
_j
Os
cext
sc
_tc
_tc
_tc
Os
5500
19.3
15.48+
13.118.0
11.1920
960
720
760
840
800
880 4.02
8.652.17
1.1
2.92
E
Esc
scsc
1050
1000
950
900
850
800
750
700
650
600
550
500
450
1050
1000
950
900
850
800
750
700
650
600
550
500
450
400400
Ele
vatio
n (fe
et)
B’B
Big
Mar
ine
Lake
CSAH
3
Whi
te R
ock
Lake
MN
95
Big
Mar
ine
(Jellu
ms)
Lak
e
St. C
roix
Riv
er
US6
1 CSAH
15
sc
_w
se
_e
Opo
cr
lcOpo
ce
r1r2
lc
r1
lc
crse
crOs
nt
ntce
ce
lc
cr
lclc
r1
sl
Os
cr
r2
_j
_tc
_tc
ce
ce
ss
ceOpsOps
r2
r1
Opo
sl
qu
r2
_sl
cr
r1
sx
_tc lower
sl
r2 _j
qur1
ss
_j
cr
ce
9.28
5.79*
28.7
920
920
940
_m
2.163.2
EE
E
E
scsc
sc
1050
1100
1000
950
900
850
800
750
700
650
600
550
500
450
1050
1100
1000
950
900
850
800
750
700
650
600
550
500
450
400
350
400
350
Ele
vatio
n (fe
et)
A’A
St. C
roix
Riv
er
CSAH
3
Mud
Lak
e
MN
95
Fore
st L
ake
I35
Fore
st L
ake
US6
1
Clea
r Lak
e CSAH
2
Goos
e La
ke
CSAH
1
_j
s1r1
_j
_sl
Opo
lc
xt
ce
Opo
cr
quse
xt_sl_sl
r1
nt
cr
_m _m
r3
r3
cr
r1
r1
qu
r2
qu
sl
_sl
ntxt
ce
Ops
xt
ce
_tc lower
sp
quss_tc lower
r2
pt
r2
qu
_w
xt
r1
Opo
_e_j
_w_sl
crr1
cr
se
Os
sx
Opoce
_tc lower
_tc_tc
_tc
_j _j
r1
xt
cr
cr
cr
xt
lc
sl
ce ce
r2
lc
r3
lcss
58.514.6
9.32+15.4
16.1
17
28.3880
760
920
900
800
840
E
3.632.63 4.48
2.501.4
sc
sc
sc
sc
sc
LOCATION DIAGRAM
1 0 1 2 3 4 5 MILES
1 0 1 2 4 5 6 7 83 9 KILOMETERS
SCALE 1:100 000VERTICAL EXAGGERATION X 50
Quaternary aquitards
Grouped by texture ranging from highest to lowest sand content indicating relative hydraulic conductivity.
Geologic unit code Percent sandce, cr, r1, sl
r3, vt
r2, xt
pt
>60%
>50% and ≤60%
>40% and ≤50%
>30% and ≤40%
Groundwater conditions
Symbols and labels
Land or bedrock surface
General groundwater flow direction
Geologic contact
Approximate geologic contact
Approximate equipotential contour; contour intervals 20 and 40 feet
800
Water table
Tritium age
Darker color in small vertical rectangle (well screen symbol) indicates tritium age of water sampled in well. Lighter color indicates interpreted age of water in aquifer.
Mixed: water is a mixture of recent and vintage waters (greater than 1 TU to less than 8 TU).
Well not sampled for tritium.
Vintage: water entered the ground before 1953 (less than or equal to 1 TU).
Recent: water entered the ground since about 1953 (8 to 15 tritium units [TU]).
Chloride: if shown, concentration is ≥5 ppm.(* naturally elevated, + source unknown)
32.4
Nitrate: if shown, concentration is ≥1 ppm.6.8
Arsenic: if shown, concentration is ≥2 ppb.2.19
Groundwater sample with evaporative signature
Carbon-14 (14C): estimated groundwater residence time in years.
2500
E
Enhanced-permeability zone (see Report page 9)
Groundwater moves from an overlying surficial aquifer to a buried aquifer.
Tritium concentrations may be artificially elevated by high capacity pumping.
Groundwater moves from an overlying buried aquifer to an underlying buried aquifer.
Groundwater discharges to a surface-water body.
Direction of fault movement, arrows indicate relative movement
Groundwater flows laterally.
*aquitard
*aquitard
sc, sc1, sc2*
sl*
ss, ss1, ss2
cr*
se
ce*
s1
r1*
s2
r2*
sx
xt*
s3
r3*
sp
pt*
sv
vt*
su
qu
Aquifers and aquitards
Quaternary unconsolidatedSee Figure 4 in the report for geologic unit correlation.
Bedrock Decorah Shale*
Platteville and Glenwood formations
St. Peter
Shakopee
Oneota Dolomite*
Jordan
St. Lawrence Formation*
Upper Tunnel City
Lower Tunnel City*
Wonewoc
Eau Claire Formation*
Mt. Simon
Cross Section Explanation
Interpreted tritium age is indicated by background color.
Interpreted tritium age is indicated by pattern color.
_tclower
_tc
_sl
_j
Opo
Ops
Os
Opg
Od
_w
_e
_m
scsc1sc2
ssss1ss2
1000
950
900
850
800
750
700
650
600
550
500
450
1000
950
900
850
800
750
700
650
600
550
500
450
400
350
300
250
200
400
350
300
250
200
Ele
vatio
n (fe
et)
M’M
CSAH
21
Miss
issip
pi R
iver
(Gre
y Cl
oud
Slou
gh)
Cotta
ge G
rove
St. C
roix
Riv
er
US6
1 MN
95
Miss
issip
pi R
iver
Opo _jOpo_sl
r2
_tc
_tc
_tc
_tc
r2ce
_j
_j
Opo
pt
_j
Ops
pt
Ops
Opo
_tc lower
_j
Os
Ops
r3
_sl
Opo_sl
_m
_sl
_j_j
pt
qu
_tc lower
_w
_sl
_tc
_sl
_tc lower
_tc lower
_e_w
_w _e _e
_e
_m
_jOpoce
Opo
65007.88
15.88.45*
28.7
720
760
680
30
1.1711.4
6.3
7.7
6.6
sc2sc2
scsc1
sc
1000
950
900
850
800
750
700
650
600
550
500
450
1000
950
900
850
800
750
700
650
600
550
500
450
400
350
300
250
400
350
300
250
Ele
vatio
n (fe
et)
L’L
US6
1
CSAH
19
Miss
issip
pi R
iver
MN
95
St. P
aul P
ark
CSAH
21
Cotta
ge G
rove
St. C
roix
Riv
er
pt_j
r1r1 OpoOss1
Ops_j
Ops
_tc lower
ce
_e_e
Opo
_e_w
_w
Opo
_e_tc lower
Ops Ops
_e
ss
Ops
_e
_m
_w_w
_w
_sl
ce
_sl
r1pt
ss1
sc
pt
_tc lower
Os
_j
Os
_sl
_j
_tc
ss2
_tc
_tc
_tc
_tc
_tc
_sl
_tc
_j
_tc lower_tc lowerOpo
Opor3
r1
_m_m
_m
_w
_m
_sl
_sl _j
Opsvt
r2sx
Ops
cer2
ce
2500
<1002000
2532.72551.6
33.734.2
18.9
14.8
31.4
680
720
680
760
720
760
800
840
2.33
2.78
2.09
2.19
2.81.9
6.4
12.1
5.3
1.63.1
sc
sc1
sc2
1050
1000
950
900
850
800
750
700
650
600
550
500
450
1050
1000
950
900
850
800
750
700
650
600
550
500
450
400
350
300
400
350
300
Ele
vatio
n (fe
et)
K’K
CSAH
19Ba
iley
Lake
Sou
th
St. C
roix
Riv
er
MN
95
Nor
th B
ranc
h Tr
out B
rook
(int
erm
itten
t)CS
AH21
3M W
oodb
ury
Disp
osal
Site
US6
1
Miss
issip
pi R
iver
CSAH
13
New
port
r1
_j
Opo
Ops
_w
pt
_e
_tc lower
_tc
Opg
Oposs
Od r1 ce
Opg
ce
Ops
_jOs
cevt
Opo
ss ptOpg
ce
Opo
pt
pt
r1Opg
ss
Os
_sl
_sl
_j
Ops
Opo
Ops
_j
Ctc
Os
_tc
_j
_tc lower
r1
_m
_m_w
_m
r2
_jOpo
_w
_e
_sl
_w
_e
_j
_w
Ops
_j
sc1
_tc lower
_tc
_sl
_e
_sl
2500
74.9
76.264.6
33.4
9.65+
32.9
48.1 36.0
8.21
68.0
10.9
760
800
720
760
800
840
720
840
9.5
5.57.8
3.02
33.8
2.90
E
E
E
sc
1050
1100
1000
950
900
850
800
750
700
650
600
550
500
450
1050
1100
1000
950
900
850
800
750
700
650
600
550
500
450
400
350
300
250
200
150
400
350
300
250
200
150
Ele
vatio
n (fe
et)
J’J
Lake
St.
Croi
x Be
ach
CSAH
13
St. C
roix
Riv
er
CSAH
19 Afton
MN
95
N. F
ork
Valle
y Br
anch
Cre
ekCS
AH21
Woo
dbur
y
I494
CSAH
18
Pow
ers L
ake
CSAH
16
ss
_m
Cw
_e
_m
r3
_sl
ss
_e
ss
_w
_tc lower _m
qu
_e
_w
_tc
_tc
ss
cr
se
ce ss se
Opgce
ss
ss
pt
ce
r1
Os ce
r1
Ops
sv
_j
cr
s2
r2_j
Opo
Opg
Ops
Od
_sl
vt
ce
Os
qu
r3
_tclower
_j
r2
r3
xt
25001800
53.1
28.822.1
47.8
14.4
19.9
39.7
27.5
32.4
17.9
14.8
75
12.7
760
800
840
680
720
6
6.8
1.31.2
2.2
9.1
2.6
1.51
3.03
5.4
sc
sc
sc
1050
1100
1000
950
900
850
800
750
700
650
600
550
500
450
1050
1100
1000
950
900
850
800
750
700
650
600
550
500
450
400
350
300
250
200
400
350
300
250
200
Ele
vatio
n (fe
et)
I’I
I694
MN
95
St. C
roix
Riv
erLake
Elm
o
CSAH
15
Eagl
e Po
int L
ake
CSAH
17
CSAH
13
CSAH
21
r3
sp
_j_j
_tc _e
_e
_m
r3
Os
quOpg
qu secr
cr
ce
cept
ce
se
Os
ce
cesecr
cr
cr
vt
Os
Ops
r1
ce
_w
_m
_tc lower
_sl
Os
OpsOps
Ops Opo
Opo
r2
2000
325
69.5
680
72076
0800
840
8801.12
2.3
E
sc
1050
1100
1000
950
900
850
800
750
700
650
600
550
500
450
1050
1100
1000
950
900
850
800
750
700
650
600
550
500
450
400
350
300
250
200
400
350
300
250
200
Ele
vatio
n (fe
et)
H’H
CSAH
21
I694
CSAH
15
Oak
dale
CSAH
17Sunfi
sh L
ake
St. C
roix
Riv
er
Was
hing
ton
Co la
ndfil
l
CSAH
13
ce
Os
cr
_tc
r1
ce
Od
cr
cr
crss
ce
ce
r2Os
ce
r3 pt
r1
Opg
cr
qur1
cr
Os
r2
sl
Opo
qu
_e
_m
cr
_tc
Ops Opo
Ops
r1
cr
r3
cr
r3
cr
r2
r3
_j_j
_sl
_tc lower
_w
cr
ptcece
cr
ss
ce
<100
14.8+
27.615.8
900
880
860840
800
760
720
680
E
sc
sc
1050
1000
950
900
850
800
750
700
650
600
550
500
450
1050
1000
950
900
850
800
750
700
650
600
550
500
450
400
350
300
250
200
150
100
50
0
400
350
300
250
200
150
100
50
0
Ele
vatio
n (fe
et)
G’G
CSAH
17
McD
onal
d La
ke
MN
5
Bayp
ort
CSAH
24
St. C
roix
Riv
er
MN
95
DeM
ontr
evill
e La
ke
MN
36
Clea
r Lak
e
I694
Clov
erda
le L
ake
r3
r2 s2
ce
cess
_tc
pt
Opo
Opo
_m
ce
r3
r3
ce
r2
ce
se
Os
Osr1
ce
cr
s1
ce
slOpg
Os
cr
r1
r1
sl
Ops
ce
Ops
Od
Opsr1
pt
r3
ce
xt se
cr
se
r1
crcr
Os
slsl
ss
_e
_w
_j
qu
r1
s1
_tc lower
Ops
Os
xt
_tc
Ops
_sl
_sl
Ops
xt
s1
Opo
xtvtOps
r2
cese
ce
xt
ce
_j
r2
r1
400014.4
25.1
61.6
45.09+
7.53
34.1
34.2
37.6+
13.1
119
15.8
75.6
880
920
880
720
680
760
800
840
2.58
1.110.8
2.03
3.05
E
sc
sc
sc
sc
1050
1100
1000
950
900
850
800
750
700
650
600
550
500
450
1050
1100
1000
950
900
850
800
750
700
650
600
550
500
450
400
350
300
250
400
350
300
250
Ele
vatio
n (fe
et)
F’F
Long
Lak
e
CSAH
15
Lily
Lak
e
CSAH
5
Stillw
ater
MN
95St
. Cro
ix R
iver
Was
hing
ton
Lake
CSAH
36
Sunn
ybro
ok L
ake
CSAH
17
r1
r3
r1ce
xt
ss
crss
r1 ce
cecr
cr
cr
cr
r1
r1
sl
ce
_e
_m
ss
r3 ptOs
_tc
_j
se
Ops
Opsr1 r1
cr
Os
r2
cr
Opo
sv
Opo
_j
vt
qu
_sl
Opg
_tc lower
ce
_w
pt slsl
20.116.5
14.614.8
7.69
25.5
58.2
920
720
76080
0
840
880
3.15 2.5
5.12.4
3.91
1.7E
sc
1050
1000
950
900
850
800
750
700
650
600
550
500
450
1050
1000
950
900
850
800
750
700
650
600
550
500
450
400
350
300
250
400
350
300
250
Ele
vatio
n (fe
et)
E’E
Whi
te B
ear L
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CSAH
9
MN
244
CSAH
5
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reek
(floo
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14.6+
19.7
35.2
16.1
760800
840
880
920
900
720
3.70
2.03
E
sc
sc
sc
1050
1000
950
900
850
800
750
700
650
600
550
500
450
1050
1000
950
900
850
800
750
700
650
600
550
500
450
400
350
400
350
Ele
vatio
n (fe
et)
D’D
US6
1
CSAH
8
Bald
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8.52
6.02
66.021.9
11.0
70.115.4
80084
088
0920
960
720
880
760
10.5
8.5
2.72
E E
sc
sc
sc
sc
1050
1000
950
900
850
800
750
700
650
600
550
500
450
1050
1000
950
900
850
800
750
700
650
600
550
500
450
400
350
400
350
Ele
vatio
n (fe
et)
C’C
St. C
roix
Riv
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Squa
re L
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MN
95
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17
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5500
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760
840
800
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8.652.17
1.1
2.92
E
Esc
scsc
1050
1000
950
900
850
800
750
700
650
600
550
500
450
1050
1000
950
900
850
800
750
700
650
600
550
500
450
400400
Ele
vatio
n (fe
et)
B’B
Big
Mar
ine
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Whi
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28.7
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2.163.2
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scsc
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1050
1100
1000
950
900
850
800
750
700
650
600
550
500
450
1050
1100
1000
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900
850
800
750
700
650
600
550
500
450
400
350
400
350
Ele
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A’A
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28.3880
760
920
900
800
840
E
3.632.63 4.48
2.501.4
sc
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Hydrogeologic Cross Sections
By James A. Berg and J. Wes Rutelonis
2019
Groundwater Atlas of Washington CountyCounty Atlas Series C-39, Part B
Plate 9 of 9 Hydrogeologic Cross Sections
H–Hʹ through M–Mʹ
Minnesota Department of Natural ResourcesCounty Atlas Program mndnr.gov/groundwatermapping
To accompany atlas Report and Plates 7–8.
Southern cross sections I–Iʹ, J–Jʹ, K–Kʹ, L–Lʹ, and M–Mʹ
Explanation of H–Hʹ is on Plate 8.See Report Figure 4 for associated geologic units.This group of cross sections is characterized by a thin layer of surficial sand and sandy till (approximately 50 to 100 feet thick), shallow bedrock aquifers with likely karst-type porosity and permeability, a deep buried bedrock valley (200 to 250 feet), and faulted bedrock in the east. All of these factors contribute to deep penetration of recent and mixed tritium-age water that can range as deep as 600 feet with the combined effects of deep fractured bedrock from the buried bedrock valleys and lateral groundwater flow. The location of the main buried bedrock valley relative to the groundwater divide is a major control of the direction of mixed tritium-age groundwater flow in the Jordan (_j) and Upper Tunnel City (_tc) aquifers. On cross section I–Iʹ, the buried valley lines up approximately with the groundwater divide in the Jordan aquifer. Mixed tritium-age water was found on both sides of the buried valley. A similar tritium distribution is shown on J–Jʹ. Two carbon-14 age dates in the Jordan aquifer are shown on the western and eastern portions with values of 2,500 and 1,800 years respectively, values typical of the Jordan aquifer in the southern part of the county.The eastern portion of I–Iʹ contains an unusual layering of residence time. Vintage tritium-age water is found above mixed tritium-age water in the Jordan aquifer. Pumping from the Upper Tunnel City and a naturally downward gradient may be drawing mixed tritium-age water deeper than would be expected. Another notable feature is the evaporative signature from a shallow well downgradient from Lake Elmo, signifying lake discharge to groundwater.On the eastern side of cross sections K–Kʹ and L–Lʹ, all the bedrock aquifers were displaced upward by a horst structure, as much as 200 to 300 feet compared to areas west of the horst. On K–Kʹ, recent and mixed tritium-age water was interpreted in the shallow Platteville (Opg), St. Peter (Os), and Prairie du Chien aquifers (Ops and Opo). Evaporative signature water was found south of Bailey Lake in the Prairie du Chien aquifer (Ops) and overlying surficial aquifers. Just west of CSAH 13 for approximately 1.5 miles the Jordan aquifer apparently has some protection from the deep (unfractured) condition of the Oneota (Opo) as indicated by the vintage tritium-age water. Otherwise, the Jordan aquifer appears to get recharge water of mixed tritium age from the buried bedrock valley at CSAH 19 and a shallower bedrock valley farther to the west (east of Newport). Farther west on K–Kʹ two Jordan aquifer groundwater samples contain mixed tritium-age water where it might be expected to contain vintage tritium-age water from upwelling of older water to the Mississippi River. These locations could be evidence of pumping effects drawing mixed tritium-age water deeper than would otherwise be expected. On the western portion of L–Lʹ similar residence time conditions appear to exist within the St. Peter and Prairie du Chien aquifers (Ops), which are completely filled with recent and mixed tritium-age water. Portions of the Jordan aquifer containing mixed tritium-age water were sourced from the buried valley east of CSAH 19. A sample collected west of US 61 had recent tritium age and a carbon-14 residence time of less than 100 years. These values seem anomalous in an otherwise mixed tritium setting and may be influenced by high-capacity pumping or a leaky well casing.Further west on L–Lʹ (between St. Paul Park and the Mississippi River) a Jordan well contained vintage tritium-age water possibly from upwelling of older water to the Mississippi River. The carbon-14 values of 2,000 and 2,500 years were typical of the Jordan aquifer in the southern part of the county.On cross section M–Mʹ almost the entire Jordan aquifer is within 200 feet of the surface and probably contains recent and mixed tritium-age water. The exceptions are the far western and eastern portions that contain vintage tritium-age water due to the upwelling of older water discharging to the Mississippi and St. Croix rivers. At four locations, vintage tritium-age samples from the Upper Tunnel City aquifer (_tc) and the Lower Tunnel City Group (_tc lower) appear protected by the St. Lawrence aquitard (_sl). These locations include a site in Cottage Grove and three sites east of MN 95. West of US 61 an Upper Tunnel City groundwater sample had an estimated carbon-14 age of 6,500 years. Two sites in the Jordan with mixed tritium-age water are near and downgradient of faults that may have enhanced downward flow in these areas. These locations include a site just east of US 61 and a site west of CSAH 21.
This map was compiled and generated in a geographic information system. Digital data products are available from the DNR County Atlas Program at mndnr.gov/groundwatermapping.
This map was prepared from publicly available information. Every reasonable effort has been made to ensure the accuracy of the factual data on which this map interpretation is based. However, the DNR does not warrant the accuracy, completeness, or any implied uses of these data. Users may wish to verify critical information; sources include both the references in the report and information on file in the offices of the Minnesota Geological Survey and the DNR. Every effort has been made to ensure the interpretation shown conforms to sound geologic and cartographic principles. This map should not be used to establish legal title, boundaries, or locations of improvements.
Base modified from Minnesota Geological Survey, Washington County Geologic Atlas, Part A, 2016.
Universal Transverse Mercator projection, zone 15N, North American Datum of 1983. North American Vertical Datum of 1988.
500 Lafayette Road St. Paul, MN 55155-4025 888-646-6367 or 651-296-6157 mndnr.gov
This information is available in alternative format on request.
The Minnesota DNR prohibits discrimination in its programs and services based on race, color, creed, religion, national origin, sex, public assistance status, age, sexual orientation, or disability. Persons with disabilities may request reasonable modifications to access or participate in DNR programs and services by contacting the DNR ADA Title II Coordinator at [email protected] or 651-259-6157. Discrimination inquiries should be sent to Minnesota DNR, 500 Lafayette Road, St. Paul, MN 55155-4049; or Office of Civil Rights, U.S. Department of the Interior, 1849 C Street NW, Washington, DC 20240.
© 2019, State of Minnesota, Department of Natural Resources and the Regents of the University of Minnesota
Prepared and published with the support of the Minnesota Environment and Natural Resources Trust Fund and the Clean Water, Land and Legacy Amendment
T. 32 N.
T. 31 N.
T. 30 N.
T. 29 N.
T. 28 N.
T. 27 N.
T. 26 N.
R. 21 W. R. 20 W.
44° 52' 30" N.
44° 45' N.
45° N.
45° 07' 30" N.
45° 15' N.
92° 45' W. 92° 52' 30" W. 93° W.
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Symbols
Part B line of cross section shown on this plate
Well used to generate cross section*
A A’ Part B line of cross section shown on Plate 8
H H’
Part A line of cross sectionB B’
1 0 1 2 3 4
SCALE 1:300 000
1 0 1 2 4 5 6 7 83 9 KILOMETERS
5 MILES
N
*Not all wells are displayed in cross section view due to the high density of wells.
T. 32 N.
T. 31 N.
T. 30 N.
T. 29 N.
T. 28 N.
T. 27 N.
T. 26 N.
R. 21 W. R. 20 W.
44° 52' 30" N.
44° 45' N.
45° N.
45° 07' 30" N.
45° 15' N.
92° 45' W. 92° 52' 30" W. 93° W.
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5500
6500
2500
6000
3000
9000
2500
4000
2500
<100
2000
6500
1800
5500
25,000
2000
<100
2500
<100
<100
20,000
<100
1 0 1 2 3 4
SCALE 1:300 000
1 0 1 2 4 5 6 7 83 9 KILOMETERS
5 MILES
Symbols and labels
Carbon-14 (14C): estimated groundwater residence time in years.
5500
Line of cross section (Part B)BB ’
Sampled well and aquifer symbols
Prairie du Chien
Jordan, Jordan–St. Lawrence
Tunnel City
Wonewoc–Eau Claire
Eau Claire
Wonewoc–Mt. Simon, Mt. Simon, Mt. Simon–Hinckley
N
Cross section locations and wells used for cross section generation
Carbon-14: estimated groundwater residence time in years
