Ground-Water Levels in the Ozark Aquifer along the

Viburnum Trend, Southeastern Missouri, 2001–05

Scientific Investigations Report 2006–5220

U.S. Department of the Interior

U. S. Geological Survey
Cover Photograph: Observation well VT-1 and Viburnum Mine 28 in the background, July 2006. 

Photographs courtesy of Michael J. Kleeschulte, U.S. Geological Survey. 
Ground-Water Levels in the Ozark Aquifer 

along the Viburnum Trend, Southeastern 

Missouri, 2001–05 

By Michael J. Kleeschulte 

Scientific Investigations Report 2006–5220 

U.S. Department of the Interior 

U.S. Geological Survey 
U.S. Department of the Interior 

DIRK KEMPTHORNE, Secretary 

U.S. Geological Survey 

P. Patrick Leahy, Acting Director 

U.S. Geological Survey, Reston, Virginia: 2006 

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Suggested citation: 

Kleeschulte, M.J., 2006, Ground-water levels in the Ozark aquifer along the Viburnum Trend, Southeastern Missouri, 

2001–05: U.S. Geological Survey Scientific Investigations Report 2006–5220, 21 p. 
iii 

CONTENTS 

Abstract. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1


Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1


Previous Investigations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5


Purpose and Scope. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5


Acknowledgments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5


Methodology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5


Ground-Water Levels in the Ozark Aquifer Along the Viburnum Trend. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7


Summary and Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14


References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15


Figures 

1.	 Map showing location of the Viburnum Trend and study area. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2


2.	 Stratigraphic column for an exploration hole in Reynolds County, Missouri, and a general


litholgic description of formations in the Viburnum Trend. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3


3.	 Geohydrologic section from southeastern Crawford County along the Viburnum Trend to west-


central Reynolds County. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4


4. General site location system used for this report. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7


5–7. Graphs showing:


5.	 Monthly and cumulative departure from normal precipitation for the East Ozarks


region, Missouri, 1996 through 2005. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8


6.	 Daily mean depth-to-water for monitoring wells along the Viburnum Trend and


daily precipitation in Salem, Missouri, 2002 through 2005. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9


7.	 Difference between daily mean water levels, monthly precipitation, and


cumulative monthly precipitation at wells VT-1 and VT-8, 2002 through 2005. . . . . . . . . . . . . . . . . 13


8.	 Schematic diagram of well VT-1, well VT-8, and climatological station locations . . . . . . . . . . . . . . . . . . 14


Tables 

1.	 Well-construction data for Viburnum Trend monitoring wells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6


2.	 Manually measured water levels in Viburnum Trend monitoring wells, 2001 through 2005. . . . . . . . . 19


3.	 Input parameters for aquifer-test analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Conversion Factors and Datum 

Multiply By To obtain 

Length 

inch (in.) 

foot (ft)

mile (mi)

25.4 

 0.3048 

 1.609 

millimeter (mm) 

meter (m) 

kilometer (km) 

Area 

square foot (ft2

) 0.09294 square meter (m2) 

Volume 

gallon (gal)

million gallons (Mgal)

cubic foot (ft3)

 3.785 

 3,785 

 0.02832 

liter (L) 

cubic meter (m3) 

cubic meter (m3) 

Flow rate 

cubic foot per second (ft3/s)

gallon per minute (gal/min)

million gallons per day (Mgal/d)

 0.02832 

 0.06309 

 0.04381 

cubic meter per second (m3/s) 

liter per second (L/s) 

cubic meter per second (m3/s) 

Transmissivity* 

foot squared per second (ft2/s) 0.0929 meter squared per second (m2/s) 

iv 

Vertical coordinate information is referenced to the National Geodetic Vertical Datum of 1929 

(NGVD 29). Altitude, as used in the report, refers to distance above or below NGVD 29. NGVD 29 

can be converted to the North American Vertical Datum of 1988 (NAVD 88) by using the National 

Geodetic Survey conversion utility available at URL http://www.ngs.noaa.gov/TOOLS/Vertcon/vertcon.html. 

Horizontal coordinate information is referenced to the Datum of 1927 (NAD 27). 

*Transmissivity: The standard unit for transmissivity is cubic foot per day per square foot times foot 

of aquifer thickness [(ft3

/d)/ft2]ft. In this report, the mathematically reduced form, foot squared per 

second (ft2/s), is used for convenience. 
Ground-Water Levels in the Ozark Aquifer along the 

Viburnum Trend, Southeastern Missouri, 2001–05 

by Michael J. Kleeschulte 

Abstract 

During 2001, eight monitoring wells were installed along 

the Viburnum Trend to determine if dewatering of lead-zinc 

mines in the St. Francois aquifer affected water levels in the surficial Ozark aquifer. The well locations were chosen specifically 

to investigate the effects of different mining scenarios. Before 

data collection, much of southern Missouri, including the Viburnum Trend area, experienced a drought that began in late 1999. 

Dry conditions existed in the area until early 2002, about the 

time data recorders were installed in the monitoring wells. 

The water-level data indicate no long-term, continuous 

water-level declines occurred from 2002 to 2005 at five monitoring wells (VT-2, VT-3, VT-5, VT-6, and VT-7), four of 

which are over active mining areas. Conversely, these five wells 

had increasing water levels with time. Another well (VT-4) 

placed over an active mining area, did have a long-term waterlevel decline (about 30 foot) that developed during the study. 

On a local scale, the water-level data from this well reinforces 

conclusions of previous investigations that report small areas of 

drawdown in the Ozark aquifer may be present along the Viburnum Trend as the result of mine dewatering. 

A monitoring well (VT-1) installed over an abandoned 

mine where flooding is occurring showed an increasing waterlevel trend. Another well (VT-8) installed in an area where mining was expected to occur after well installation showed a lowering ground-water trough in 2004 and 2005. Comparing 

monthly precipitation and daily mean water-levels differences 

at these two wells indicates that for most of the period from 

2002 to 2005, the converging water-level difference that 

occurred can be explained by local precipitation differences 

rather than being mining induced. Local precipitation differences, however, do not explain the 15-foot decrease in waterlevel difference that was observed during the period January 

through June 2004. 

Introduction 

The initial discovery of lead-zinc deposits near Viburnum, 

Missouri (fig. 1), was made in 1955 and ore production began 

in the mid-1960s (Wharton, 1975). Between 1960 and 1973, 

eight underground operating mines opened (Warner and others, 

1974) along a 30-mile, north-south trending zone that can have 

minable ore hundreds of feet wide or wider. Currently (2006), 

some of the original mines have been shut down, other mines 

have opened, and several of the mines have been connected 

underground. This entire mining area is referred to locally as the 

Viburnum Trend (fig. 1). 

Predominantly carbonate rock sequences of the Ordovician Canadian Series and Upper Cambrian Series (Roubidoux 

Formation to the base of the Lamotte Sandstone) overlie granites and rhyolites of the Precambrian basement rock (fig. 2). 

Locally, the Roubidoux Formation is present and exposed on 

some of the highest ridge tops, but generally the formations 

from the Gasconade Dolomite to the Potosi Dolomite crop out 

(Middendorf and others, 2003). The rocks from the Roubidoux 

Formation to the base of the Potosi Dolomite form the surficial 

Ozark aquifer, the primary source of water for private- and public-water supplies and major springs in southern Missouri. Formations of the Ozark aquifer typically were not logged or cored 

by mining companies during exploration drilling and, therefore, 

could not be defined on the geohydrologic section shown in figure 3. The St. Francois confining unit underlies the Ozark aquifer and consists of dense carbonates and shales of the DerbyDoerun Dolomite and Davis Formation. Regionally, the physical and hydraulic characteristics of the confining unit generally 

impede the movement of ground water between the overlying 

Ozark aquifer and the underlying St. Francois aquifer (Imes and 

Emmett, 1994). The carbonate (dolostone and limestone) and 

sandstone St. Francois aquifer consists of the Bonneterre Formation and the underlying Lamotte Sandstone. The Bonneterre 

Formation is the host formation for the largest and most important lead-zinc deposits in southeastern Missouri (Wharton, 

1975). Other than the city of Viburnum (fig. 1), which uses 

water from an abandoned mine as a drinking-water source, the 

St. Francois aquifer usually is not used along the Viburnum 

Trend because the shallower Ozark aquifer adequately meets 

the drinking water needs of the region. 

Dewatering of the St. Francois aquifer is the result of drainage of ground water into mined areas and pumpage of this water 

to the surface. Typical pumpage from the St. Francois aquifer for 

mine dewatering in the Viburnum Trend is estimated to range 

from 25 to 27 million gallons per day (Warner and others, 1974; 

Denis N. Murphy, The Doe Run Company, written commun., 

2000 and 2004). This pumpage rate has been occurring for most 

of the more than 40 years the mines have been in operation. 
91 ̊15' 91 ̊00' 

21 

32 

72 

49 

21 

72 

19 

49 

32 

49 

KK 

72 

21 

72 

32 

49 

106 

WASHINGTON CRAWFORD 

DENT IRON 

REYNOLDS SHANNON 

DENT 

Courtois 

C r ooked Creek 

Big 

River 

Fork 

Middle 

We s t Bee Fo r k 

Sinking 

C

B

reek

i g 

Creek 

Creek 

B r u s h y 

Cr eek 

Logan 

Lo gan 

Sinking 

Curr ent 

River 

Strother Cr eek 

Black 

R iv e r 

Black 

River 

Creek 

Creek 

Huzzah 

Creek

Creek 

Fork 

Viburnum 

Ellington 

Bixby 

Salem 

14 miles 

Steelville 

14 miles 

Round Spring 

8 miles 

Bunker 

A

A’

ML-019640 

CL-99B11 

CL-73C04 

ML-018970 

ML-024242 

ML-024245 

ML-026096 

CL-95V47 

CL-92DR03

R 

R 

R 

R 

R 

R 

R 

VT-8 

VT-7 

VT-6 

VT-5 

VT-4 

VT-3 

VT-2 

VT-1 

R 

T. 36 N. 

37 ̊45' 

T. 35 N. 

T. 34 N. 

T. 33 N. 

37 ̊30' 

T. 32 N. 

T. 31 N. 

T. 30 N. 

37 ̊15' 

Base from U.S. Geological Survey digital data, 1:100,000, 1994 

Universal Transverse Mercator projection, 

Zone 15 

R. 03 W. R. 02 W. R. 01 W. 

EXPLANATION 

St. Francois Mountains Precambrian 

rock outcrop area 

Generalized trace of section, borehole VT-8 R 

ML-024245 

A’ locations used to draw section, and A identifier (section shown in fig. 3) 

0 1 2 3 4 5 MILES 

01 2 3 4 5 KILOMETERS 

R. 01 E. 

Mine 

Monitoring well with recorder 

and identifier 

Viburnum Trend 

Study 

area 

MISSOURI 

Figure 1. Location of the Viburnum Trend and study area. 

2 Ground-Water Levels in the Ozark Aquifer along the Viburnum Trend, Southeastern Missouri, 2001–05 
FEET 

1,300 

General lithologic description 

900 Eminence Dolomite; Light gray, massive, cherty dolostone with some 

quartz druse near the base. The chert is ‘rusty’ in appearance and

 porous. In the upper part of the formation, the bedding is thinner 

St. Francois aquifer St. Francois

confining unit 

Ozark aquifer

Ordovician

(Canadian Series) 

Geologic

Geohydrologic unit

unit 

Cambrian

(Upper Series) 

Overburden-residuum; Soils, clay, chert fragments 

Roubidoux Formation; Residue included in the residuum. 

Where the formation has not weathered to residuum, it is a 

dolostone, light gray to brown, fine-grained, cherty, some

 quartzose sandstone. 

1,200 

1,100 

Gasconade Dolomite; Light gray, argillaceous dolostone that gradually

 grades into more massive, medium- to coarse-grained, gray dolostone 

containing abundant dense to porous chert. The basal Gunter

 Sandstone Member is an arenaceous dolomite, containing thin,

 discontinuous lenses of sandstone. 

1,000 

800 and more uniform than in the lower part. 

700 

Potosi Dolomite; Light gray to dark brown, moderately crystalline, mediumto fine-grained, massive, very drusy dolostone. Three separate lithologies

 have been assigned to the formation. Algal reef rock normally is a

 medium-crystalline dolomite, with ‘honeycomb’ or ‘pipe’ druse. The oolite

600 and carbonate beds are medium crystalline and characterized by druse

that follows horizontal bedding planes. The carbonate slime beds are very

 dense, fine crystalline, and thin-bedded. 

500 

Derby-Doerun Dolomite; Upper part is thin-bedded, fine- to medium-grained, 400 argillaceous, light-buff to light-gray dolostone. 

Lower part is essentially thick-bedded to massive, non-cherty dolostone,

 usually light gray to buff with occasional dark gray color. The dolostone is 

300 fine- to medium-grained, dense, argillaceous, and can contain shale. 

Davis Formation; Upper part consists of thin-bedded, fine-grained, 

200 argillaceous, light gray to tan dolostone overlain by dolostone similar

to that near the base.


Middle part contains moderate shale and fine-grained, light-gray limestone.


Lower part contains light gray, coarse-grained, massively bedded, highly
 100 

glauconitic dolostone with interbedded green or black shale. 

Bonneterre Formation; Upper part contains the Whetstone Creek Member

 (the base of which is the False Davis shale horizon) and the Sullivan 

 Siltstone. In general terms, the upper part is massive, coarsely 

crystalline, light gray and contains numerous vugs lined with dolomite or 

calcite crystals and is cavernous or pitted on exposed surfaces. Four

 major carbonate facies occur: back reef facies, reef facies, off-shore facies,

False Davis 

NGVD 29 

100 

and open marine shelf. 


Lower part is completely crystalline, fine-grained, buff-colored dolostone 


and sparingly mottled with gray dolostone.
 200 

Lamotte Sandstone; Light gray to reddish brown, red, and shades of yellow

 brown, thin- to massive-bedded quartz sandstone with a siliceous cement. 300 The upper part is commonly not well cemented. 

400 

500 

Precambrian basement rock; Granite and rhyolite porphyry. 600 Precambrian Basement confining unit

Missouri Department of Natural 

NOTE: The geologic names used in this Resources, Division of Geology 

figure follow the nomenclature used by and Land Survey (DGLS) 

the DGLS. General lithologic description Log number 19937 modified from Fletcher (1974). Reynolds County 

T. 32 N., R. 02 W., 33CDB 

Figure 2. Stratigraphic column for an exploration hole in Reynolds County, Missouri, and a general lithologic 

description of formations in the Viburnum Trend. 

Introduction 3 
rmation

Lamotte Sandstone

FEET


1,000


500

NGVD 29

500

1,000 0 5 10 MILES 

A'

Ordovician

(Canadian Series)

Cambrian

(Upper Series)

Precambrian 

Ozark

aquifer

St. Francois

confining unit

St. Francois

aquifer

Basement

confining

unit 

A

Geohydrologic

unit 

Geologic

unit 

ML-019640 

ML-026096 

ML-018970 

ML-024242 

ML-024245 

CL-95V47 

CL-92DR03 

CL-99B11 

CL-73C04 

Y CRAWFORD COUNT

IRON COUNTY 

IRON COUNTY 

Y REYNOLDS COUNT

West Fo rk Black River 

Bee Fork 

Log an Creek 

Fault 

Fault 

Derby-Doerun Dolo

mite 

Davis Formation 

Bonneterre Fo 

Well VT-2 

Well VT-3 

Well VT-5 

TD

891 feet 

TD

1,550 feet 

TD

1,400 feet

1,330 feet  TD

TD? TD

? 

TD? TD

? 

TD799 feet 

TD

310 feet 

TD

190 feet 

TD

170 feet 

0 5 10 KILOMETERS

VERTICAL SCALE GREATLY EXAGGERATED ML-019640


CL-99B11


TD


? 


EXPLANATION 

DGLS borehole identification numberMining company borehole identification numberTotal depth of boreholeTotal depth is approximateGeologic contact—Dashed where approximate 

Borehole data from Missouri Department of Natural Resources,
Division of Geology and Land Survey (DGLS) and The Doe Run
 Company. Precambrian surface modified from Fletcher (1974) 


Figure 3. Geohydrologic section from southeastern Crawford County along the Viburnum Trend to west-central Reynolds County (trace shown on Fig. 1). 

4 Ground-Water Levels in the Ozark Aquifer along the Viburnum Trend, Southeastern Missouri, 2001–05
Methodology 5 

Previous Investigations 

Previousinvestigations have been conducted to investigate 

whether or not continued pumpage from the St. Francois aquifer 

(mine dewatering) has affected water levels in the overlying 

Ozark aquifer. In 1974, the University of Missouri - Rolla completed a study that analyzed the pumping effects on the St. Francois aquifer and the Ozark aquifer (Warner and others, 1974). 

Water-level data were collected from 20 observation wells in 

the St. Francois aquifer in the vicinity of 5 active mines, and 

from 9 observation wells in the Ozark aquifer that were around 

the southern-most mine. This study concluded that depending 

on the mine location, the potentiometric surface of the St. Francois aquifer declined 600 to 1,200 feet as a result of mine dewatering. The aquifer thickness typically ranges from 300 to 600 

feet, but because the aquifer is confined, the potentiometric surface extends much higher than the top of the aquifer. During 

mine dewatering, the pressure head is lowered first. After the 

potentiometric surface has declined below the top of the aquifer, the aquifer will begin to be dewatered. The report also concluded that the effect of pumping in the St. Francois aquifer 

probably is not great beyond a distance of about 5 miles from 

any of the mines, and that the areas of major effect are more 

restricted than the stated 5-mile distance. The report also stated 

that as mining continues, the affected area is not expected to 

widen much from east to west, but as the mines become interconnected, a continuous narrow dewatered zone throughout the 

length of the Viburnum Trend in the St. Francois aquifer is 

expected. The report also concluded that water-level changes in 

the surficial Ozark aquifer were not large (Warner and others, 

1974). The small water-level declines in the Ozark aquifer are a 

result of the effective confining capability of the formations 

overlying the St. Francois aquifer in the area, specifically the St. 

Francois confining unit (figs. 2 and 3). 

Another study that investigated the drawdown effects of 

mine dewatering on the Ozark aquifer was conducted in 1999 

by the U.S. Geological Survey (Kleeschulte, 2001). A pre-mining (before 1960) potentiometric surface was drawn for the 

Ozark aquifer using 118 historic water-level measurements 

reported by well drillers to the Missouri Department of Natural 

Resources when these wells were drilled. This pre-mining 

potentiometric surface was compared digitally to a potentiometric surface drawn for the Ozark aquifer from 66 water levels 

measured in 1999 from monitoring, domestic, and public-supply wells along the Viburnum Trend. The general conclusion 

was that no large cones of depression were apparent in the 

potentiometric surface of the Ozark aquifer along the Viburnum 

Trend as a consequence of mining activity. Some localized 

leakage of water from the Ozark aquifer into the St. Francois 

aquifer probably is occurring at ventilation shafts and inadequately plugged exploration boreholes; therefore, small areas of 

measurable drawdown may exist (Warner and others, 1974; 

Miller and Vandike, 1997; Kleeschulte, 2001). 

Much of the Viburnum Trend occurs under the sparsely 

populated Mark Twain National Forest. The area includes scattered parcels of private property that contain isolated homesteads or small communities, with most of the private property 

being concentrated along major roads or along stream valleys. 

Consequently, there is not an adequate spatial distribution of 

wells directly over active mines along the Viburnum Trend for 

water-level measurements. This was the situation during the 

two previous studies (Warner and others, 1974; Kleeschulte, 

2001); therefore, the locations where water-level measurements 

in the Ozark aquifer were needed most corresponded to areas 

where the aquifer was least accessible. Because of this, it was 

decided to drill monitoring wells directly over active mining 

areas along the Viburnum Trend, and to continually monitor 

water levels to better assess possible water-level declines in the 

Ozark aquifer. Through the cooperation of the U.S. Department 

of Agriculture, Forest Service (Forest Service) and The Doe 

Run Company, locations of possible well sites on properties 

managed by these entities were determined and access to areas 

meeting these criteria were approved; subsequently, eight monitoring wells were installed during the fall of 2001 for waterlevel monitoring by the U.S. Geological Survey. 

Purpose andScope 

This report describes water-level data in the surficial 

Ozark aquifer collected from October 2001 through December 

2005 from eight monitoring wells located along the Viburnum 

Trend. The data were collected to evaluate the effects of 

ground-water discharge, primarily from mine dewatering in the 

deeper St. Francois aquifer, on the water levels in the Ozark 

aquifer. The monitoring wells constructed for this study are distributed in a generally linear pattern about 27 miles long from 

north to south (fig. 1). 

Acknowledgments 

Gratitude is expressed to The Doe Run Company for 

allowing access to mine maps during the monitoring well site 

location process and for allowing monitoring well installations 

to occur on their property. Special recognition is extended to 

Joe Wagner (Chief Geologist, The Doe Run Company) for his 

assistance and cooperation during the site location process and 

Denis Murphy (Safety and Environmental Manager, The Doe 

Run Company) for gathering information on the status of mining beneath the monitoring wells. Gratitude also is expressed to 

the Forest Service for allowing well installations on the Mark 

Twain National Forest, with a special recognition to Sarah Bradley (Wildlife Biologist, Forest Service) who provided oversight during the drilling in the National Forest. 

Methodology 

Even though the eight monitoring wells are distributed 

along almost the entire length of the Viburnum Trend, it is recognized that the water-level data from each well represents only 
Table 1. Well-construction data for Viburnum Trend monitoring wells. 

[Units for latitude and longitude are in North American Datum of 1927; DDMMSS, degrees, minutes, seconds; MM-DD-YYYY, month, day, year; 

units for altitudes are in feet above National Geodetic Vertical Datum of 1929.] 

Well 

name 

Latitude 

(DDMMSS) 

Longitude 

(DDMMSS) 

General land office 

coordinates 

Date of 

construction 

(MM-DD-YYYY) 

Altitude of 

land 

surface 

(feet) 

Height of 

measuring 

point 

(feet) 

Depth of 

well 

(feet) 

Bottom of 

casing 

(feet) 

Well VT-1

Well VT-2

Well VT-3

Well VT-4

Well VT-5

Well VT-6

Well VT-7

Well VT-8

374252 

373905 

373628 

373307 

373056 

372853 

372608 

371910 

0910654 

0910710 

0910648 

0910740 

0910638 

0910618 

0910633 

0910811 

T35N R02W 26DBB 

T34N R02W 11DAA 

T34N R02W 25CAC 

T33N R02W 14ACC 

T33N R02W 25CDD 

T32N R02W 12ADB 

T32N R02W 25ACD 

T30N R02W 02CBA 

12-10-2001 

12-11-2001 

12-10-2001 

12-04-2001 

12-03-2001 

11-05-2001 

10-31-2001 

11-05-2001 

1,140 

1,420 

1,360 

1,410 

1,160 

1,150 

1,165 

990 

2.4 

2.1 

2.0 

2.2 

2.1 

3.2 

2.2 

2.1 

110 

310 

190 

390 

170 

250 

275 

110 

80 

120 

80 

190 

126 

210 

250 

80 

6 Ground-Water Levels in the Ozark Aquifer along the Viburnum Trend, Southeastern Missouri, 2001–05 

the local ground-water conditions in the Ozark aquifer in the 

vicinity of the well. To monitor the Ozark aquifer along the 

entire Viburnum Trend would require many more wells. However, it is assumed the water-level data from these eight selected 

sites would be adequate to detect continued, large-scale 

regional drawdown in the Ozark aquifer along the Viburnum 

Trend if it were occurring. 

The monitoring well locations were chosen specifically to 

represent the various possible mining scenarios. Well VT-1 was 

installed over a mine that was scheduled to be shut down after 

the well was installed. Data from well VT-1 would monitor 

water levels in the Ozark aquifer during the period of rising 

water levels in the St. Francois aquifer after mine closure. Mining ceased and the pumps were removed from the mine in 

August 2004, allowing the mine to flood (Denis N. Murphy, 

The Doe Run Company, written commun., 2004). Wells VT-5 

and VT-8 were installed above unmined areas but where mine 

workings were progressing toward at the time of well installation. These sites would be used to monitor baseline water levels 

in the Ozark aquifer and monitor the effects of mine dewatering 

on the Ozark aquifer as mining begins in an area. The remaining 

five wells (VT-2,VT-3, VT-4, VT-6, and VT-7) were placed 

directly over active mining areas where dewatering had been 

occurring for an extended time. 

The eight monitoring wells were drilled from October 

through December 2001. To expedite the Forest Service special 

use permitting process, well sites were chosen that were of adequate size and void of trees. Because of existing modifications 

to the land surface, wells VT-3, VT-4, and VT-8 are believed to 

occupy former lead-zinc exploration drilling sites that had boreholes that were plugged and abandoned years earlier. Typically, 

the monitoring wells were installed by air rotary drilling to less 

than 100 feet below the top of the water table. Six-inch steel surface casing was installed in all wells to a minimum depth of 80 

feet below land surface to prevent the borehole walls from caving and to prevent surface drainage from entering the well (table 

1). In several wells, more casing was required so that the bottom 

of the casing could be set in solid rock. Wells were open hole 

from the bottom of the surface casing to total depth. The wells 

were instrumented in February 2002 with transducers that measure and record water-levels at 1-hour intervals. 

Well locations are described by latitude and longitude 

coordinates and by the General Land Office coordinate system. 

Using this coordinate system (fig. 4), the first three sets of numbers representing a borehole location designate township, 

range, and section. The letters that follow indicate quarter section, quarter-quarter section, and quarter-quarter-quarter section. The quarter sections are represented by letters A, B, C, and 

D in counterclockwise order, starting in the northeastern quadrant. The altitude of land surface was determined from 7.5­

minute U.S. Geological Survey topographic maps. Because of 

the steep topography of the area, the topographic maps have a 

contour interval of 20 feet, with an accuracy of plus or minus 

0.5 the contour interval (plus or minus 10 feet). 

During each site visit, manual water-level measurements 

were made at each monitoring well. The measurements were 

read to the nearest 0.01 foot using a calibrated electric tape and 

referenced to land surface (table 2, at the back of the report). 

When possible, the same electric tape was used at each well to 

measure water levels. The manual water-level measurements 

are considered the standard and were used to verify the accuracy 

of the transducer measurements, which were adjusted as necessary. 

All eight monitoring wells were originally equipped with 

water-level recorders that were custom-length, electronic pressure transducers, vented to atmospheric pressure. The daily 

mean water level was computed from continual hourly waterlevel measurements obtained from the pressure transducers. 

Unless otherwise stated, it is believed that the reported transducer water level is accurate to within 0.05 foot of the actual 

water level in the well. Instrument drift corrections to the 

recorded data were occasionally required when the transducer 
R. 01 W. R. 01 E. R. 02 E. R. 03 E. 

T. 37 N. 

T. 36 N. 

T. 35 N. 

T. 38 N. 

T. 39 N. 

T. 40 N. 

WASHINGTON 

COUNTY 

1 

12 

13 

25 

36 

2 

11 

14 

23 

26 

35 

3 

10 

15 

22 

27 

34 

4 

9 

16 

21 

28 

33 

5 

8 

17 

20 

29 

32 

6 

7 

18 

19 

30 

31 

A 

C 

B T. 36 N., R. 01 E., 24BCD 

D 

C 

C 

Figure 4. General site location system used for this report 

24 

A A 

D 

D B 

B 

Ground-Water Levels in the Ozark Aquifer along the Viburnum Trend 7 

measurement and the field water-level measurement had a discrepancy of more than the reporting accuracy of 0.05 foot. 

Daily water-level values for each well are given in the Missouri Water Science Center annual data report for the corresponding water years 2002 to 2005 (Hauck and Nagel, 2003, 

2004, 2005; Hauck and Harris, 2006). Several wells have 

extended period of missing record caused by equipment or 

power failures. Well VT-4 had missing record caused by waterlevel declines that began during January 2003. By February 

2003, water levels in the well dropped below the level of the 

transducer. Attempts were made to lower the transducer to keep 

it below the water surface, but the design of the transducer would 

not permit this modification of its intended use for an extended 

period of time. In June 2003, that transducer was replaced with 

a transducer that was not vented to atmospheric pressure. This 

resulted in the water-level data that were collected from June 

2003 until September 2004 being less accurate than the data 

from the vented transducers, and is assumed to be plus or minus 

1-foot. In May 2005, the vented pressure transducer in well VT2 malfunctioned and could not be repaired. This transducer was 

also replaced with an unvented one. The water-level data accuracy collected from unvented transducers after September 2004 

was improved by barometric pressure compensation. 

Ground-Water Levels in the Ozark Aquifer 

along the Viburnum Trend 

Much of southern Missouri, including the Viburnum 

Trend area, experienced a drought that began in late 1999 (University of Missouri-Columbia, 2006) about 2 years before the 

well installations. Monthly and cumulative departure from normal precipitation from 1996 through 2005 for the East Ozarks 

region of Missouri, which includes the Viburnum Trend 

[National Oceanic and Atmospheric Administration (NOAA), 

1996–2005] are shown in figure 5. From 1997 through early 

1999, there was an excess of precipitation when compared to 

normal monthly amounts. In the summer of 1999, a period of 

less than normal precipitation began and continued into 2002. 

This dry period culminated during the spring and summer of 

2001, when the cumulative precipitation since 1996 was more 

than 11 inches below normal (fig. 5B). The water-level recorders were installed in the monitoring network wells during February 2002, which typically is early in the recharge period of the 

annual water-level fluctuation cycle (fig. 6). The combination 

of the drought and subsequent dry conditions and the time of 

year the continual water-level data collection began, created a 

situation where the initial water-level data were abnormally 

low. The dry conditions abated during the winter and spring of 

2002 (fig. 5B), and water levels rose in all eight monitoring 

wells into the early summer of 2002 (fig. 6). 

Hydrograph data representing all eight wells for the period 

of record show the two shallowest wells (wells VT-1 and VT-8; 

table 1 and fig. 6A) have water levels less than 100 feet below 

land surface and are the most responsive to precipitation events. 

The hydrograph data for these two wells are plotted with the 

daily precipitation totals reported by the NOAA climatological 

station at Salem, Missouri. Depending on antecedent conditions, a precipitation event of 1-inch or more generally caused 

both wells to respond almost immediately with water-level 

increases. The water-level increase in well VT-8 typically is 

larger compared to well VT-1 and peaks several days earlier. 

Occasionally, however, the overall water-level increase is 

greater in well VT-1 than in well VT-8. Because these two wells 

are about 27 miles apart and represent the northernmost and 

southernmost wells, this discrepancy may be more a function of 

differences in precipitation at each well, rather than differences 

in geohydrologic conditions at the wells. 

Unlike the two shallowest wells, the response to individual 

precipitation events in the middle groups of wells (VT-3, VT-5, 

VT-6, VT-7, and VT-2; fig. 6B and C), where the depth to water 

is more than 100 feet below land surface, is more subdued or 

non-existent. The hydrographs for these wells show the 

observed water-level changes primarily were seasonal fluctuations. The low initial water levels for these wells are assumed to 

be a result of the prior drought and subsequent dry conditions. 

Manual water-level measurements were being made in all wells 

of the monitoring well network a couple of months before the 

transducers were installed (table 2). For the middle groups of 

wells, the lowest measured water levels occurred before trans­
CUMULATIVE DEPARTURE FROM NORMAL PRECIPITATION, 


IN INCHES DEPARTURE FROM NORMAL PRECIPITATION, IN INCHES


8 

6 

4 

2 

0 

-2 

-4 

20 

A 

15 

10 

5 

0 

-5 

-10 

-15 

1996 

B 

1997 1998 1999 2000 2001 2002 2003 2004 2005 

Data from National Oceanic and Atmospheric

 Administration (1996–2005) 

igure 5. Monthly (A) and cumulative (B) departure from normal precipitation for the East Ozarks region, Missouri, 1996 through 2005. 

8 Ground-Water Levels in the Ozark Aquifer along the Viburnum Trend, Southeastern Missouri, 2001–05 

F

ducer installation or within a few weeks after the transducers 

were installed. This is in contrast to the shallow wells (VT-1 and 

VT-8), where the initial water-level measurements were not 

among the lowest during the study. Water levels in the middle 

group of wells continued to recover during the winter and 

spring of 2002, and the resulting water levels are considered to 

be more representative of normal hydrologic conditions. The 

annual water-level declines that normally occur each fall into 

winter (trough) for this set of wells did not fall below the initial 

conditions throughout the remainder of the study, and generally 

the altitude of the trough rose each succeeding year and water 

levels increased with time. An evaluation of the seasonal peaks 

also indicated no continuous water-level declines occurred during the study. Based on these observations, it is concluded no 

long-term, continuous water-level declines occurred from 2002 

to 2005 at wells VT-2, VT-3, VT-5, VT-6, or VT-7. All these 

wells, except VT-5, were placed over active mining areas. 

Well VT-4, the deepest of the monitoring wells with a total 

depth of 390 feet below land surface (fig. 1 and table 1), is 

located over an active mining area near the middle of the Viburnum Trend. The well penetrates the Gasconade and Eminence 

Dolomites, and possibly the top of the Potosi Dolomite. The 

bottom of the well is about 400 feet above the top of the DerbyDoerun Dolomite of the St. Francis confining unit. The 

hydrograph from monitoring well VT-4 was unique (fig. 6D) in 

that it is the only well in the network that had a long-term waterlevel decline that did not recover. On a local scale, the waterlevel data from this well reinforces conclusions of previous 

investigations that report small areas of drawdown in the Ozark 

aquifer may be present along the Viburnum Trend as a result of 

mine dewatering. 

During the summer and fall of 2002, the water-level fluctuation for well VT-4 was not synchronous with the other seven 

wells. Whereas water levels in the other monitoring wells 
Precipitation data from National Oceanic and

 Atmospheric Administration (2002–05) 

A 

PRECIPITATION, IN INCHES 

3 

4 

5 

1 

0 

2 

20 

30 

40 

50 

60 

70 

80 

VT-1 

VT-8 

DEPTH BELOW LAND SURFACE, IN FEET 

150 

110 

120 

130 

140 

VT-3

VT-5 

VT-6 

B 

VT-7 

VT-2 

C 

240 

250 

260 

270 

280 

390 

350 

360 

370 

380 

VT-4 

D 

J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D 


2002 2003 2004 2005


Figure 6. Daily mean depth-to-water for monitoring wells along the Viburnum Trend (A–D) and daily precipitation in Salem, Missouri 

(A), 2002 through 2005. 

Ground-Water Levels in the Ozark Aquifer along the Viburnum Trend 9 
10 Ground-Water Levels in the Ozark Aquifer along the Viburnum Trend, Southeastern Missouri, 2001–05 

started decreasing in June and July 2002, water levels in well 

VT-4 continued to increase into January 2003. Either the water 

level in well VT-4 was still recovering from the prior prolonged 

dry conditions, or the observed water-level response was the 

result of factors other than localized precipitation or normal seasonal responses. 

The most prominent feature of the well VT-4 hydrograph 

is the water-level decline of about 30 foot, that began in January 

2003. This occurred 6 to 7 months after the other seven wells 

appeared to have recovered from the prior prolonged dry conditions, and 11 months after the transducer and data recorder were 

installed in the well. It is unknown what may have occurred to 

initiate the water-level decline observed in the well in January 

2003, but equilibrium between recharge and withdrawal was 

not reached until July 2003, when the water level stabilized. 

Possible explanations for the drawdown observed at well VT-4 

are a decrease in recharge, an increase in withdrawal from the 

aquifer, or a change in the hydraulic characteristics of the aquifer or underlying confining unit allowing more water to flow 

from the aquifer. Because precipitation amounts had returned to 

normal levels by summer 2002, and there are no known domestic or public-water supply wells in the area, the lack of recharge 

or additional well pumpage do not appear to be the cause for the 

water-level decline. Increased flow to area springs that have the 

monitoring well in their recharge area is a possibility, but this 

would not be possible to verify because no historic or recent 

spring data have been collected in this remote area. A more 

plausible explanation for the water-level decline is a change in 

subsurface hydraulic characteristics of the Ozark aquifer or the 

underlying St. Francois confining unit in the vicinity of the 

well, which would allow additional ground-water flow, either 

diffuse or discrete, to occur from the Ozark aquifer. 

Two potential pathways exist in the vicinity of well VT-4 

for discrete ground-water flow to occur out of the Ozark aquifer 

and into the St. Francois aquifer. It is probable that well VT-4 

occupies the site of an old exploration borehole that was plugged 

and abandoned years earlier. Also, a mine ventilation shaft that 

was installed years before the monitoring well was drilled (Sarah 

Bradley, Forest Service, oral commun., 2005) is present about 

775 feet northeast of the well. It is hypothesized that water may 

be moving from the Ozark aquifer into the mine workings in the 

St. Francois aquifer through either the former exploration borehole that was plugged and abandoned, or through the nearby 

mine ventilation shaft. The mining company was contacted and 

informed of the situation and they reported no abnormal inflow 

of water into the mine in the vicinity of well VT-4 (Bob Dunn, 

The Doe Run Company, oral commun., 2003). 

Well VT-4 is not the only well in the monitoring network 

that occupies a former exploration drill site or has a nearby ventilation shaft. A conscious effort was made to avoid locating 

monitoring wells near these types of structures during the well 

site selection process. However, it was not possible to totally 

avoid this situation, especially in the areas where active mining 

was occurring. Consequently, wells VT-3 and VT-8 are probably on former exploration drill sites, and wells VT-2 and VT-6 

are within 1,000 feet of ventilation shafts; however, water levels 

in these wells show no indication of being affected by these 

nearby auxiliary structures. 

The hypothesis of downward ground-water leakage from 

the Ozark aquifer into the St. Francois aquifer through the 

exploration borehole or the nearby ventilation shaft resulting in 

localized areas of drawdown, is consistent with the conclusions 

of an incident reported by Miller and Vandike (1997). Their 

report states a large diameter ventilation shaft (vent shaft 50) 

that was drilled about 1,000 feet northwest of the village of 

Bixby (fig. 1), in the northern part of the Viburnum Trend, was 

determined to be leaking. These shafts are normally cased only 

through the surficial materials and produce small quantities of 

water. Vent shaft 50 encountered well-developed, solution 

enlarged openings in the Potosi Dolomite. Initially, inflow into 

the underlying mine (1,000 feet below land surface) was several 

hundred gallons per minute. This inflow did not interfere with 

mining operations and was pumped back to the surface. The 

inflow into the mine, however, resulted in substantial waterlevel declines in the Ozark aquifer around Bixby. Most of the 

domestic wells in the area were less than 200 feet deep and produced from a permeable zone in the Eminence Dolomite at a 

depth of about 150 feet. The permeable zone was dewatered by 

the shaft, and most of the domestic wells, though not dry, would 

no longer sustain yields of more than 3 gallons per minute. The 

mining company grouted the bedrock around the shaft reducing 

the volume of water draining into the mine to 50 to 70 gallons 

per minute. The shaft was plugged in September 1991, after it 

was no longer needed. Almost immediately water levels in the 

Ozark aquifer began recovering in the area, and recovery of 

water levels to pre-vent shaft 50 conditions took about 3.5 years 

(Miller and Vandike, 1997). 

A cursory aquifer-test analysis using the Theis solution 

(Freeze and Cherry, 1979) for unconfined aquifers was performed on the drawdown data collected from well VT-4 to estimate the discharge rate needed to achieve the observed drawdown. In the analysis, well VT-4 represented the observation 

well, and the ventilation shaft and exploration borehole were each 

used in separate simulations to represent a pumping well, 

although both more closely resemble drains. Many of the input 

parameters needed for the analysis were known, others had to be 

estimated (table 3). The thickness of the Ozark aquifer was calculated from available well logs in the area and assigned a saturated 

thickness of 450 feet. The observation well (VT-4) opening is the 

interval from the bottom of the well casing to the bottom of the 

well (190 to 390 feet). In the ventilation shaft scenario, the distance from the observation well to the pumping well (ventilation 

shaft) was measured from air photos to be 775 feet. In the borehole scenario, the distance was estimated to be 40 feet. Because 

ventilation shafts typically are cased only through the surficial 

material, and because the exploration borehole plug in the St. 

Francois confining unit is assumed to have failed for this scenario, both are considered to fully penetrate the Ozark aquifer and 

continue into the St. Francois aquifer. The casing and effective 

well radius of the ventilation shaft and exploration borehole were 

assumed to be 2.0 and 0.25 feet, respectively. The aquifer was 

considered to be unconfined and isotropic. 
Table 3. Input parameters for aquifer-test analysis. 

[ft, foot; ft

2

/s, squared foot per second; ft3/s, cubic foot per second] 

Parameter Ventilation shaft Exploration borehole 

Aquifer saturated thickness 450 ft 450 ft 

Observation well opening From 190 to 390 ft From 190 to 390 ft 

Distance to pumping well 775 ft 40 ft 

Pumping well Fully penetrating Fully penetrating 

Pumping well casing radius 2 ft 0.25 ft 

Effective pumping well radius 2 ft 0.25 ft 

Aquifer type Unconfined Unconfined 

Estimated 

Aquifer Isotropic Isotropic 

Transmissivity 0.006 to 0.0009 ft

2

/s 0.006 to 0.0009 ft

2/s 

Storage coefficient 0.01 to 0.30 0.01 to 0.30 

Pumping rate 0.2 to 2.5 ft3/s No determination 

Ground-Water Levels in the Ozark Aquifer along the Viburnum Trend 11 

. 

The transmissivity values were unknown but estimates 

were calculated from hydraulic conductivity values for the 

Ozark aquifer reported by Imes and Emmett (1994) for their 

regional ground-water study of the Ozark Plateaus aquifer system and from Steffen Robertson and Kirsten, Inc. (1988) while 

performing aquifer testing in Bixby wells. Data from these two 

sources were used to estimate the upper [0.006 square foot per 

second, (ft2/s)] and lower (0.0009 ft2/s) transmissivity limits for 

the analysis. The storage coefficient value was assigned “text 

book” limits for unconfined aquifers ranging from 0.01 to 0.30 

(Freeze and Cherry, 1979). The start time at which the discharge began was also unknown and was varied from 0 to 250 

days before the drawdown was first observed in well VT-4. No 

solution could be achieved when using a discharge start time 

beyond 250 days and the predefined limits for the transmissivity 

and storage coefficient. 

There are an infinite number of solutions to the analysis 

because of the various unknown parameters; consequently, a 

range of discharge values was determined. During the analysis, a discharge start time was assigned. The discharge rate 

was then varied and the Theis type curve was adjusted to 

determine if the discharge rate and start time combination was 

possible for the resulting drawdown data and the predefined 

limits for the transmissivity and storage coefficient. The 

steady-state conditions that occurred after the drawdown (fig. 

6D) could be the result of a boundary condition that was 

encountered at a farther distance from the ventilation shaft 

than well VT-4, or perhaps leakage (recharge) into the aquifer. 

For this cursory analysis, the standard Theis approach is considered appropriate to estimate possible water discharge rates 

from the aquifer. 

The analysis indicated that the discharge needed to cause 

the observed drawdown in well VT-4 ranged from 0.2 to 2.5 

cubic foot per second (90 to about 1,120 gallons per minute) in 

the ventilation shaft scenario. A solution could not be achieved 

using the exploration borehole scenario and the predefined limits for the transmissivity and storage coefficient; therefore, no 

discharge was estimated for this scenario. 

In addition to monitoring the Ozark aquifer over active 

mining areas, another aspect of this study was to observe waterlevel responses in areas where the initial geohydrologic conditions at a well might change during the study. Well VT-1 was 

placed over a closed mine that was allowed to start flooding in 

August 2004. If mine dewatering had affected the Ozark aquifer 

in this area, a water-level increase in the aquifer near the mine 

would be a reasonable expectation after the mine floods. After 

the mine fills with water and the water level reaches the top of 

the St. Francois aquifer (base of the St. Francois confining unit), 

a pressure head would develop in the St. Francois aquifer. As 

the pressure head increases, the hydraulic gradient between the 

Ozark aquifer and the St. Francois aquifer would decrease. If 

the pressure head in the St. Francois aquifer would meet or 

exceed the water level in the Ozark aquifer, this increased head 

in the St. Francois aquifer could increase water levels in the 

Ozark aquifer by either reducing downward leakage or inducing 

an upward flow of water into the Ozark aquifer. The hydrograph 

for VT-1 (fig. 6A) does not indicate that water levels were consistently higher immediately after the August 2004 mine closure. The water-level trough that occurred in fall 2004, and the 

subsequent recovery period that occurred during winter and 

spring of 2005, were similar to the corresponding features of the 

preceding years and reflect seasonal water-level fluctuations. 
12 Ground-Water Levels in the Ozark Aquifer along the Viburnum Trend, Southeastern Missouri, 2001–05 

The annual trough that developed in fall 2005 is not as well 

defined, and is about 4 feet higher than any previous recorded 

trough observed in well VT-1 during the study. The current status of the mine flooding is unknown; however, it may be several 

years before a pressure head develops in the St. Francois aquifer 

at well VT-1. Another explanation for the high water-level 

trough in fall 2005 is the greater than normal amount of precipitation that occurred in the area (fig. 5) during September 2005. 

Water levels in the deeper wells (VT-2, VT-5, and VT-6) also 

follow a similar pattern of increasing water-level trough altitudes with time. 

Wells VT-5 and VT-8 were placed in front of mine workings with the expectation of the mine eventually reaching the 

area beneath the well sites. If mine dewatering was going to 

affect water levels in the Ozark aquifer in these areas and cause 

continuous large-scale drawdown, it is expected that waterlevel declines in the Ozark aquifer would occur after mine 

workings arrive beneath the wells. Consequently, water levels 

would continue to decline annually below the previously 

observed lowest values of each preceding year. In plan view, 

the mine workings have presently (2006) approached within 

110 feet of well VT-5 and 10 feet of well VT-8 (Denis Murphy, 

The Doe Run Company, written commun., 2006). The vertical 

distance between the bottom of the wells and mines is measured 

in many hundreds of feet. The hydrograph for well VT-5 shows 

no indication of continuous drawdown occurring as a result of 

mine dewatering in the vicinity of the well. The hydrograph 

instead shows that the base of the water-level trough each year 

is consistently higher than the previous year. The hydrograph 

for well VT-8, however, does show a lowering of the waterlevel trough in 2004 and 2005. This is the expected response if 

mining has reached the well site and mine dewatering was 

affecting water levels in the well. 

Wells VT-1 and VT-8 are the shallowest wells in the network and have similar construction (table 1). The water levels 

in the two wells generally responded similarly and maintained 

a consistent amount of separation during the first 2 years of the 

study but this appears to have changed in 2004 (fig. 6A). To 

investigate this, the water-level difference at the two wells was 

calculated by subtracting the daily mean water level for well 

VT-8 from well VT-1 (fig. 7A). The data show the water-level 

difference between the two wells has converged from over 20 

feet to less than 5 feet, during the 4 years of the study. 

It is unknown if the converging water levels in wells VT-1 

and VT-8 are a natural ground-water response to local precipitation in the vicinity of the wells or mining induced. If mining 

induced, the convergence can be explained by the rising water 

levels in well VT-1 as the mine beneath it floods and the falling 

water levels in well VT-8 as mine dewatering begins beneath 

the well. Because of the short lag time between precipitation 

events and water-level responses in these two wells (fig. 6A), 

the correlation between water-level response and precipitation 

at these two wells can be investigated. 

No usable precipitation data were available in the vicinity 

of either well VT-1 or VT-8, so precipitation data for the period 

2002 through 2005 were tabulated from NOAA reporting climatological stations in Bunker, Ellington, Round Spring, 

Salem, and Steelville (figs. 1 and 8). These climatological stations were chosen based on their proximity and spatial distribution in relation to the monitoring wells. It is assumed the estimated monthly precipitation totals calculated from the available 

precipitation data is the amount that occurred at each well. The 

estimated monthly precipitation occurring at well VT-1 was 

calculated by averaging the daily precipitation values at Bunker, Salem, and Steelville and then adding the average daily values for each month. The estimated monthly precipitation for 

well VT-8 was calculated using the same technique as well VT1 but with climatological data reported for Bunker, Ellington, 

and Round Spring. During 2002 through 2005, it was estimated 

well VT-1 received 183.6 inches of precipitation and well VT8 received 186.0 inches (National Oceanic and Atmospheric 

Administration, 2002–2005). This 2.4-inch difference is not 

considered significant over a 4-year period, and these precipitation totals do not explain the decreasing water-level difference 

observed between well VT-1 and well VT-8. 

The monthly precipitation difference and the daily mean 

water-level difference between wells VT-1 and VT-8 also were 

compared to determine if a correlation exists between these two 

parameters. The monthly precipitation difference at the two 

well sites was calculated by subtracting the monthly totals 

determined for well VT-1 from the corresponding monthly 

totals determined for well VT-8 (fig. 7B). When a positive number was calculated (greater monthly rainfall at well VT-8), the 

water level at well VT-8 would be expected to rise more than 

the water level at well VT-1 where the rainfall was less. Therefore, the water-level difference between the wells would be 

expected to increase. Conversely, when a negative monthly precipitation difference was calculated, the water-level difference 

would be expected to decrease. 

The results of the comparison between monthly precipitation and water-level differences indicate a correlation may exist 

for most of the period 2002 through 2005. During 2002 through 

June 2003, well VT-8 received about 5 inches less precipitation 

than well VT-1 (fig. 7B and C) and the water-level difference 

between these wells shows a slightly decreasing trend. In February 2002, when the study began, the water-level difference 

was about 25 feet and by June 2003 this difference decreased to 

less than 20 feet. This is the anticipated water-level response if 

local precipitation was the cause for the water-level convergence. 

During the period July through December 2003, conditions changed and well VT-8 received about 7 inches more precipitation than well VT-1. This excess rainfall at well VT-8 not 

only halted the downward trend in water-level difference 

between the two wells, but reversed the trend and the waterlevel difference increased during this period. This also was the 

expected response if local precipitation was controlling waterlevel changes. 

From January through June 2004, another transition occurs 

in the mean daily water-level difference. The water-level difference decreased from about 25 feet to about 10 feet. During this 

same period, there was no significant overall precipitation dif­
Ground-Water Levels in the Ozark Aquifer along the Viburnum Trend 13 

 CUMULATIVE MONTHLY PRECIPITATION DIFFERENCE, 


IN INCHES MONTHLY PRECIPITATION DIFFERENCE, IN INCHES DAILY MEAN WATER-LEVEL DIFFERENCE, IN FEET


40 

A 35 

TREND LINE FOR SELECTED PERIODS 30 

25 

20 

15 

10 

5 

0 

2.5

B 2.0


 GREATER PRECIPITATION AT WELL VT-8


1.5 

1.0 

0.5 

0 

-0.5

-1.0 

-1.5 

-2.0 GREATER PRECIPITATION AT WELL VT-1 

-2.5 

3 

C 

2


 GREATER PRECIPITATION AT WELL VT-8


1


0


-1


-2


-3


-4


-5


 GREATER PRECIPITATION AT WELL VT-1


-6
 J F M A M J J A SON D J F M A M J J A S OND J F M A M J J A S O N D J F M A M J J A S O N D

2002 2003 2004 2005 

Precipitation data from National Oceanic and 

Atmospheric Administration (2002–05) 

Figure 7. Difference between (A) daily mean water levels (VT-1 minus VT-8), (B) monthly precipitation, and (C) cumulative monthly 

precipitation at wells VT-1 and VT-8, 2002 through 2005. 
Steelville 

Well 

24.0 miles

23.7 miles 

14.4 miles

16.8 miles 11.1 miles

14.0 miles 

Salem 

Well VT-1 

Bunker

N

Round Spring VT-8 Ellington

Figure 8. Schematic diagram of well VT-1, well VT-8 , and 

cli matological station locations. 

14 Ground-Water Levels in the Ozark Aquifer along the Viburnum Trend, Southeastern Missouri, 2001–05 

ference at the two wells; consequently, precipitation differences 

do not appear to be the cause for the decreasing water-level difference during this period. 

From June 2004 to June 2005, there was no substantial precipitation difference at the two wells. As expected, if local precipitation was controlling water-level changes, the water-level 

difference between the two wells generally remained between 10 

to 15 feet. At the end of June 2005, there was an interruption in 

data collection at well VT-8. When data collection resumed at 

the well in October 2005, the water-level difference between the 

two wells had decreased to less than 5 feet with no corresponding precipitation difference to explain the sudden decrease. 

The water-level data from October through December 2005 

have considerable scatter, but over this short period there 

appears to be an upward trend in the water-level difference. Well 

VT-8 received about 1 inch more precipitation than well VT-1 

(fig. 7C) during this period, and the result was that the waterlevel difference between the wells increased. This is the 

expected response if local precipitation were controlling the 

water-level changes. 

It is concluded that for most of the period from 2002 to 2005, 

the converging water-level difference that occurred at wells VT-1 

and VT-8 is a result of local precipitation differences rather than 

being mining induced. However, local precipitation differences do 

not explain the 15-foot decrease in water-level difference that was 

observed during the period January through June 2004. 

Summary and Conclusions 

During 2001, eight monitoring wells were installed in a 

generally linear pattern along the Viburnum Trend to determine 

if dewatering in the lead-zinc mines in the St. Francois aquifer 

has affected water levels in the surficial Ozark aquifer. The well 

locations were chosen specifically to be in areas where mining 

was scheduled to cease and mine flooding would occur, in areas 

where mine workings were progressing toward and would be 

occurring after well installation, or directly over active mining 

areas. Typically, the wells were drilled to less than 100 feet 

below the top of the water table. 

Before data collection, much of southern Missouri, including the Viburnum Trend area, experienced a drought that began 

in late 1999. Dry conditions existed in the area until early 2002, 

about the time when the wells were equipped with water-level 

recorders. This dry period culminated during the spring and 

summer of 2001, when the cumulative precipitation from 1996 

to 2001 was more than 11 inches below normal in the East 

Ozarks region. 

The water-level data indicate no long-term, continuous 

water-level declines occurred from 2002 to 2005 at five monitoring wells, four of which are over active mining areas. Conversely, these five wells (VT-2, VT-3, VT-5, VT-6, and VT-7) 

had increasing water levels with time. On a local scale, however, the water-level data reinforces conclusions of previous 

investigations that state small areas of drawdown in the Ozark 

aquifer may be present along the Viburnum Trend as a result of 

mine dewatering. A long-term water-level decline of about 30 

foot that developed during the study at monitoring well VT-4, 

which also is over an active mining area, indicates an isolated 

area of drawdown in the Ozark aquifer. While the cause of the 

water-level decline is unknown, it is hypothesized that the 

drawdown was caused by a change in subsurface hydraulic 

characteristics of the Ozark aquifer or the underlying St. Francois confining unit in the vicinity of the well. This allowed additional ground-water flow, either diffuse or discrete, to occur 

from the Ozark aquifer. It also is hypothesized that water may 

be moving from the Ozark aquifer into the mine workings in the 

St. Francois aquifer in the vicinity of the well through either a 

former exploration borehole that was plugged and abandoned, 

or a nearby mine ventilation shaft. Because these same type 

auxiliary structures are present at other monitoring well locations where no water-level declines were observed, the presence 

of these structures does not necessarily infer that water-level 

declines will occur or are occurring near all these type structures. 

Well VT-1 is over an abandoned mine that is being 

allowed to flood. During 2005, water levels in this well showed 

an upward trend. Wells VT-5 and VT-8 were placed in areas 

where mining was expected to occur after the start of the study. 

In plan view, the mine workings have presently (2006) 

approached within 110 feet of well VT-5 and 10 feet of well 

VT-8. The vertical distance between the wells and mines is 

measured in many hundreds of feet. The hydrograph for well 

VT-5 shows no indication that continuous water-level declines 

are occurring. The hydrograph for well VT-8, however, shows 

a lowering of the ground-water trough in 2004 and 2005. 

It was investigated whether the water-level response in 

these two wells is a natural ground-water response to local precipitation in the vicinity of the wells as opposed to being mining 

induced. Comparing monthly precipitation and daily mean 
References 15 

water-levels differences at these two wells indicates that for 

most of the period from 2002 to 2005, the converging waterlevel difference that occurred can be explained by local precipitation differences rather than being mining induced. Local precipitation differences, however, do not explain the 15-foot 

decrease in water-level difference that was observed during the 

period January through June 2004. 

References 

Fletcher, C.S., 1974, The geology and hydrogeology of the New 

Lead Belt, Missouri: University of Missouri-Rolla, unpublished M.S. thesis, 91 p. 

Freeze, R.A., and Cherry, J.A., 1979, Groundwater: PrenticeHall, Inc., Englewood Cliffs, New Jersey, 604 p. 

Hauck, H.S., and Harris, T.E., 2006, Water resources data, Missouri water year 2005: U.S. Geological Survey Water-Data 

Report MO–05–1, 724 p. (published annually), CD-ROM. 

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Report MO–04–1, 798 p. (published annually), CD-ROM. 

Imes, J.L., and Emmett, L.F., 1994, Geohydrology of the Ozark 

Plateaus aquifer system in parts of Missouri, Arkansas, Oklahoma, and Kansas: U.S. Geological Survey Professional 

Paper 1414–D, 127 p. 

Kleeschulte, M.J., 2001, Effects of lead-zinc mining on groundwater levels in the Ozark aquifer in the Viburnum Trend, 

Southeastern Missouri: U.S. Geological Survey WaterResources Investigations Report 00–4293, 28 p. 

Middendorf, M.A., and others, 2003, Geologic Map of Missouri: Rolla, Missouri, Missouri Department of Natural 

Resources, Missouri Geological Survey, 1 sheet. 

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of Missouri: Water Resources Report Number 46, Missouri 

State Water Plan Series, Vol. II, Rolla, Missouri, Missouri 

Department of Natural Resources, Division of Geology and 

Land Survey, 210 p. 

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1996–2005, Climatological data annual summary, Missouri: 

Asheville, North Carolina, National Climatic Center, 

v. 100–109, no. 13. 

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2002–2005, Climatological data monthly, Missouri: 

Asheville, North Carolina, National Climatic Center, 

v. 106–109, no. 1–12. 

Steffen Robertson and Kirsten, Inc., 1988, Results of phase I 

groundwater investigation, Bixby, Missouri: Lakewood, Colorado, 35 p. 

University of Missouri–Columbia, 2006, University of 

Missouri Information: accessed June 28, 2006, at URL http:/ 

/www.drought.unl.edu/dm/archive/99/drmon0928.htm 

Wharton, H.M., 1975, Introduction to the southeast Missouri 

lead district, in Vineyard, J.D., ed., The geology and ore 

deposits of selected mines, Viburnum Trend, Missouri: Division of Geology and Land Survey, Report of Investigations 

58, p. 3–14. 

Warner, D.L., Fletcher, C.S., and Cesare, J.A., 1974, Effect of 

mining operations on ground water levels in the New Lead 

Belt, Missouri: Rolla, Missouri, University of MissouriRolla, Project Number A–060–MO, 86 p. 
Table

Table 2. Manually measured water levels in Viburnum Trend monitoring wells, 2001 through 2005. 

[All water levels are depth-to-water in feet below land surface; --, no data; maximum measured water level for well is in box; minimum water level for 

Well VT-1 Well VT-2 Well VT-3 Well VT-4 Well VT-5 Well VT-6 Well VT-7 Well 

Date Water level Water level Water level Water level Water level Water level Water level Water 

10/31/2001 -- -- -- -- -- -- 142.31 --11/19/2001 -- -- -- -- -- 143.59 142.38 50.11/26/2001 -- -- -- -- -- 143.73 142.42 51.12/04/2001 -- -- -- -- 137.54 -- -- --12/13/2001 70.28 291.29 117.56 -- -- -- -- --12/14/2001 70.05 285.28 117.56 358.14 137.95 143.84 142.60 51.01/15/2002 -- -- 118.39 -- -- -- -- --01/16/2002 -- -- -- -- 137.81 143.26 142.69 48.01/17/2002 68.15 274.52 -- -- -- -- -- --02/12/2002 65.06 273.38 -- -- -- -- -- --02/13/2002 65.57 273.44 119.04 360.59 -- 141.61 -- --02/21/2002 66.12 272.65 118.88 359.54 136.96 -- -- --02/22/2002 -- -- -- -- 137.06 -- 142.97 41.03/07/2002 64.54 272.38 118.94 359.84 136.54 140.78 142.60 42.03/19/2002 -- -- -- -- -- -- 142.06 --04/29/2002 56.39 258.72 -- -- -- -- -- --05/06/2002 -- -- 115.75 359.00 130.20 130.95 -- --05/07/2002 -- -- -- -- -- -- 140.81 33.07/15/2002 62.10 243.29 112.83 356.19 127.55 128.59 139.56 40.

07/22/2002 -- -- -- -- -- -- -- 40.09/10/2002 65.80 247.08 114.35 353.54 128.87 132.42 139.74 41.11/14/2002 67.61 252.55 116.47 352.34 130.79 135.51 140.48 48.

01/17/2003 64.53 257.24 118.50 356.44 131.16 137.65 141.46 47.02/12/2003 69.70 258.24 118.89 363.74 131.56 138.45 141.91 49.03/14/2003 61.45 256.87 118.50 369.04 130.39 137.70 141.63 43.04/18/2003 59.63 253.66 117.14 372.77 129.48 136.16 141.21 40.05/21/2003 58.41 250.75 115.71 377.54 127.58 134.14 140.83 40.06/06/2003 -- -- -- 377.09 -- -- -- -- 
Table 2. Manually measured water levels in Viburnum Trend monitoring wells, 2001 through 2005.—Continued 

[All water levels are depth-to-water in feet below land surface; --, no data; maximum measured water level for well is in box; minimum water level for 

Well VT-1 Well VT-2 Well VT-3 Well VT-4 Well VT-5 Well VT-6 Well VT-7 Well 

Date Water level Water level Water level Water level Water level Water level Water level Water 

06/17/2003 58.64 248.95 114.88 378.59 127.41 133.16 140.36 40.07/18/2003 64.41 249.07 114.93 379.61 127.85 133.69 140.44 42.08/13/2003 65.93 250.08 115.53 380.66 128.22 133.80 140.38 43.09/12/2003 66.40 251.30 115.96 379.14 128.70 134.49 140.24 44.09/25/2003 -- -- -- -- 129.31 135.20 140.64 45.10/14/2003 70.89 253.45 116.79 378.18 -- -- -- --10/27/2003 -- -- -- -- 130.58 136.16 140.77 47.11/14/2003 73.20 257.15 118.13 381.39 130.77 137.07 141.18 48.01/06/2004 60.56 257.71 119.04 382.66 128.68 133.67 141.06 36.01/08/2004 -- -- -- 381.15 -- -- -- --03/03/2004 63.37 254.63 117.02 381.09 127.40 131.97 139.91 45.04/22/2004 -- -- -- 378.95 126.00 130.29 138.97 47.05/18/2004 58.87 249.57 114.45 380.85 124.33 127.39 138.51 42.06/08/2004 60.52 248.35 114.19 381.06 124.42 127.83 138.23 48.07/15/2004 64.62 248.25 114.55 380.20 125.07 129.62 138.01 54.09/01/2004 69.96 250.77 116.00 381.88 126.60 132.15 138.21 58.09/02/2004 -- 250.45 -- -- -- -- -- --09/13/2004 -- 251.21 -- -- -- -- -- --10/05/2004 -- -- -- -- -- -- -- 60.10/18/2004 74.02 252.95 116.71 378.36 127.57 133.33 138.27 --12/08/2004 59.21 253.67 118.24 380.19 126.64 132.14 138.21 45.12/13/2004 -- -- -- -- -- -- 138.30 --12/16/2004 59.27 -- 118.34 -- -- -- 138.03 --01/17/2005 57.46 251.27 118.13 383.34 125.57 129.74 137.87 43.01/21/2005 -- 249.01 -- 378.18 -- -- -- --02/15/2005 58.77 246.94 115.93 378.02 124.18 127.74 136.90 43.03/18/2005 -- -- -- -- -- -- 136.87 50.03/29/2005 58.24 244.65 114.72 378.53 124.08 126.94 -- --05/04/2005 56.23 243.74 114.63 382.01 123.72 126.50 136.90 46.
Table 2. Manually measured water levels in Viburnum Trend monitoring wells, 2001 through 2005.—Continued 

[All water levels are depth-to-water in feet below land surface; --, no data; maximum measured water level for well is in box; minimum water level for 

Well VT-1 Well VT-2 Well VT-3 Well VT-4 Well VT-5 Well VT-6 Well VT-7 Well 

Date Water level Water level Water level Water level Water level Water level Water level Water 

06/21/2005 63.05 243.43 114.79 381.95 124.31 127.67 137.19 53.09/08/2005 67.53 246.31 116.88 381.52 125.69 130.39 138.38 60.10/05/205 -- -- -- -- -- -- -- 60.10/13/2005 63.11 247.98 117.68 380.91 126.27 131.16 139.03 61.12/01/2005 59.42 249.93 118.35 380.62 125.54 130.52 139.70 50.Minimum 56.23 243.29 112.83 352.34 123.72 126.50 136.87 33.Maximum 74.02 291.29 119.04 383.34 137.95 143.84 142.97 61.Fluctuation 17.79 48.00 6.21 31.00 14.23 17.34 6.10 27.
Kleeschulte—

Ground-WaterLevelsintheOzarkAquiferalongtheViburnum

Trend,SoutheasternMissouri,2001–05—ScientificInvestigationsReport2006–5220