GEOLOGICAL SURVEY CIRCULAR 71 

F~bruary 1950 

TECHNIQUES USED IN MINE-WATER PROBLEMS 

OF THE 

EAST TENNESSEE ZINC DISTRICT 

By Deane F. Kent 
UNITED STATES DEPARTMENT OF THE .INTERIOR 

Oscar L. Chapman, Secretary 

GEOLOGICAL SURVEY 

W. E. Wrather, Director 

WASHINGTON, D. C. 

Free on application to the Director, Geological Survey, Washington 25, D. C. 
CONTENTS 

Paqe 

Abstract .•.•...•..•.•..•.•..•..•.......•....• .' 1 

Introduction. ~ ..•......•.•...................•• 3 

General geologic relations..................... 3 

Stratigraphy. . . . . . . . . . . . • . . . • . • . . . . . . . . • . . . . . 3 

Structure ..•.............•...•........•....•• 3 

Solution Control ....•.•...•...............•.•• 3 

Precipitation ............••.....•..•..•....••.. 3 

Alnount ..................................... ~ 3 

Measurement .........•..•...........••..•..• 3 

Standard can gaqe .....•.........•...•...•.• 3 

Friez recording gage .•..........•...•..••.. 4 

Instruments for measuring flow .....•.•..•...... 4 

Current meters .......•...•...•.......•.•.• 4 

Weirs .........................•....•....• 4 

Parshall flume ......•..•...............•.. 4 

Methods of tracing water. . • . . . . . . . . . . . • . . . • . . . . 4 

Paqe 

Fluorescein dye. . . . . • • . • • • • . . . . . . . . . • • • .. • 4 

Amount of dye used... . • . . . . . . . • . . . . • • • • . 4 

Methods of introducing the dye 

into water. • . . • • • . . • . . . . . . . . . . . . . . • . • • 4 

Sampling .•..•.....••.............•••.•. 5 

Use of ultraviolet light. • . • . .. . . • . . . . . . • . . . 5 

Comparative-flow method. • . . • . . . . . . • . . . . . • . 5-

Other methods of tracing flow .......•.•.•..•. 5, 6 

Maps ..•...•...•..•...................•.••• 6 

Records ..•...............•.•....•..•••...• 6 

Applications. . . • . . • . . . • . • . • . . . • • . . • . • . • . . • . 6 

Mine A ••.••••••••••••.•••.•••••••••••••• 6 

Mine B .••.••••••••••••.•••..•.•..•.••.•• 6 

Mine C •....••••.•..••..•..•••..•..•.••.• 7 

Mine D •..••.••.•.•••••..•..•••.••.••.•.• 7, 8 

Conclusions ..•.•..•..•.......•...•.........• 8 

ILLUSTRATIONS 

Paqe 

Fiqure 1. Apparatus for introducing dye into diamond drill holes....................................... 9 

ABSTRACT 

A study of ground water as related to mining in cav- ernous limestones and dolomites in eastern Tennessee was made in 1946 by the U. S. Geological Survey. 

Surface and subsurface mapping indicated the geologic 

control of underground channels. Several methods of 

tracing water were tried and new techniques in using 

these methods evolved from the work. Rainfall data, 

1 

when correlated with ground-water volumes and velocities, gave much information as to expected pumping 

volumes for any period. The use of fluorescein dye 

for tracing the flow of the water is described and 

other methods are discussed briefly. Four examples, 

each from a different mine, are discussed in detail 

and some remedies for the problems are suggested. 

INTRODUCTION 

Mine-water problems merit far more attention than 

has been generally gr.anted, and a search through the 

literature reveals only a few scattered references to 

methods of solving such problems. Most of the articles seen emphasize costs of pumping volumes pumped, 

and the mechanical details of how the water was handled, whereas relatively few recorC:i data on _the source of the water, the geologic conditions controlling its 

movement and how they were determined, or how 

such a study might aid in developing preventive 

methods at the source. 

As early as 1Q06 excessive water caused at least 

two mines in the east Tennessee zinc district to be 

abandoned. As the years passed and more mines· were opened, and as larger areas of ground were 

cut, the costs of pumping large quantities of ground 

water rose to the point where one mine became almost 

unecomical to operate. Another mine operated under 

great difficulties because of excessive flooding during 

periods o~ very heavy rainfall. In a third, a valuable ore body was made valueless because development 

workings tapped a huge volume of water under great 

pressure. These incidents, coupled with many others, 

brought the acuteness of the problem to the attention 

of the mine owners and later to members of the U. S. 

Geological Survey who were engaged in studying the 

zinc deposits of the district. A special study of the 

mine-water problems was undertaken by the Survey 

as an engineering-geology project. This study yielded information that was applicable to the immediate 

problem, and led to the development of techniques 

that will be useful in solving similar problems elsewhere. 

The field work was done from January to June and 

from late September to early December of 1Q46. The 

writer wishes to acknowledge the complete cooperation 

of E. B. Jennings, General Manager of the Universal 

Exploration Co. , and his staff; and of H. A. Coy, 

General Superintendent of the American Zinc Co. , of 

Tennessee, and his organization~ A. S. Fry, M. A. 

Churchill, and B. C. Moneymaker of the Tennessee 

Valley Authority contributed much time, equipment, 

and valuable technical assistance throughout the project, as did many of their staff members. A. 0. 

Patterson, R. A. Laurence, and A. L. Brokaw of 

the U. s. Geological Survey helped much during the 

study. 

GENERAL GEOLOGIC RELATIONS 

Stratigraphy 

This paper is primarily concerned with the techniques used during the study and includes only that 

discussion of the geology necessary for understanding 

the methods used in studying the mine-water problems. 

All the mines studied are in Cambrian and OrdociviS.n limestones and dolomites, and present problems 

peculiar to rocks of these types. The limestones 

seem to be more soluble, altho~gl?: the dolomites 

also contain extensive solution cavities. Less soluble 

beds generally contain large quantities-of massive or 

nodular chert. 

3 

Structure 

All the mines are located on the southeast sides of 

isoclinal folds that are typical of the whole zone of 

Appalachian faulted folds comprising. much of eastern Tennessee. Northeast-trending thrust faults 

with large throws bound these folds on their northwest and southeast sides and pass near or through 

some of the mines. Related minor tear and reverse 

faults accompany the thrust faults. Each mine has 

its own fracture system and most of the mines ex- pose small local flexures plunging at varying angles 

down the dip. The strike of the formations is generally northeast and the dip ranges from almost vertical in one place to an average of 5•to 1CTSE. in the 

larger mines. 

Solution control 

The interconnected system of faults, fractures, 

and bedding planes· has allowed the development of 

an extremely ramiform system of solution cavities. 

These range from openings of a fraction of an inch to 

those more than 100 feet high and may extend for 

many miles over diverse routes. Diamond drilling 

has proved that a fault may be "tight" in one place 

even though large caves are developed along it a few 

feet away. Deep weathering is characteristic and 

the clayey overburden averages 50 feet in thickness. 

Oxidation, ·generally accompanied by solution openings, commonly extends to depths of 500 feet and in 

one place to a depth of QOO feet. The rainfall percolates through the overburden and the open cavities 

beneath it furnish a ready drain into the mines. These 

cavities often divert streams from their channels 

into the mines. 

Detailed geologic mapping gave information on the 

location of open fault zones or caves; the techniques 

used in tracing the movement of water along these zones is described below. 

PRECIPITAT~ON 

Amount 

The mean annual precipitation for this area averages more than 50 inches. Precipitation occurs 

during every month of the year, but is heaviest during late summer and winter, Commonly 1 to 3 

inches of rain falls·in one 24-hour period, which 

may or may not follow a period of light, soaking 

rains. · 

Measurement 

Early recognition of the relation between rainfall 

and the amount of mine water led to the use of gages 

to measure relative amounts of precipitation and 

runoff. The following types of measuring devices were used in this study: 

Standard can gage. The standard can gage 1/ records rainfall in hundredths of an inch by actUal 

measurement in a standard cylinder equipped with a standard measuring stick. 

1U. S. Dept. Commerce, Weather Bur., Instructions for cooperative 

observers, Circulars 8 and C, Instrument Div., 9th ed. (rev. 1941). 
Friez recording gage.- The Friez recording gage 

is a 7-day, automatically recording gage, of the weighing type, which requires only 10 minutes of service a 

week. It records total, rainfall on a graph, and the 

completed chart can be read to 0. 01 inch. 

INSTRUMENTS FOR MEASURING FLOW 

Current m~ters ~/ 

Geological Survey standard and pygmy current 

meters were used to measure velocities in streams 

in order to determine rates of flow at various points 

along the streams. 

Weirs £I 

Standard 2- and 4-foot rectangular weirs were used 

to measure flow underground and on the surface. The 

weir plates were constructed of 1/8 inch steel plate with 

the downstream edge beveled to a 45-degree angle. 

These plates were punched for screw holes and mounted on wooden dams already set in the stream. The 

labor charge for five weirs set in underground ditches 

was $15. 00 apiece, and the material cost $10. 00 per 

weir. 

Parshall flume _!/ 

A Parshall flume, a specially designed flume used 

widely for measuring flow of water in irrigated districts of the West, was installed in one mine. This 

flume required 300 board feet of 2- by 6-inch and 2-

by 12-inch seasoned pine lumber, and was lowered 

into the shaft and installed on the sump level. The advantages of the Parshall flume are that it creates a 

minimum of backwater, that it carries a flow ranging 

from 150 gallons per minute up to a maximum of 

5, 100 gallons I per minute through a throat width of 1 

foot, and that slimes do not affect its operation. The 

accuracy of the flume is not affected much by the rate 

of flow of the approaching water, and it is reliable 

enough for mine purposes. It is easily read with a 

simple staff gage, retains its accuracy through continued use over long periods, and may be constructed 

of wood, metal, or concrete. 

METHODS OF TRACING WATER 

The two principle methods tested for tracing water 

were the direct method involving fluorescein dye and 

the indirect method of comparing volumes of flow at 

different points and of relating rainfall to volume of 

flow. Different methods of introducing the dye into 

the water were tried, and a sampling system for detecting dye in the water was developed. 5/ Some alternative methods of tracing flow are dfScussed briefly 

below. · 2Corbett, D. M., and others, Stream-gaging procedure: U. S. Geol. 

Survey Water-Supply Paper 888, 245 pp., 1943. 

3

Corbett, D. M., and others, "op. cit. 

4 Parshall, Rall¥1 L., Improving the distribution of water to farmers 

by use of the Parshall measuring flume: Colorado Agr. Exper. Sta. Bull. 

488, p. 54, 1945. 

5Wenzel, L. K., Methods for determining permeability of waterbearing materials: U. S. Geol. Survey Water-Supply Paper 887, pp. 72-74, 

1942. 

4 

FLUORESCEIN DYE 

Fluorescein dye is a dark-red organic crystalline 

1compound (C2oH1205) derived from coal tar. It is 

:harmless in dilute solution. Because the color can 

be detected at great dilutions it has long been used as . ·an agent for tracing water, being so used by the Germans as early as 1877. The dye does not fluoresce in 

the solid state but, when added to water, colors the 

water green and fluoresces green under an ultraviolet 

light. The effectiveness of fluorescein is greatly reduced in highly acid waters through loss of color in a 

rather short period of time: The source of the ultraviolet light used in this study was a portable batterypowered Miner alight, manufactur.ed by IDtra-Violet 

Products, Inc., Los Angeles, Calif. The dye can be 

purchased in small quantities from any pharmacist, 

and ready and comparatively cheap sources of volume 

purchases are available. I 

Amount of dye used.- The amount of dye-used with 

each test differed according to the volume of water, 

the· distance it had to travel, and the probable time of 

travel. Some experimentation was necessary to obtain 

satisfactory results. In general, when looking for 

leaks from stream beds, a solution of 1 pound of dye 

per thousand gallons of water per minute per mile of 

probable underground travel was adequate. 

Methods of introducin the d e into the water. 6/-

Four me o s were use or e mtr uctlon of The dye. 

The first, that of putting the powder directly into a 

stream, was ineffective because all the dye did not 

go into solution rapidly and wind distributed the powder unevenly. This often led to contamination of the 

final samples, as powder would be carried on the person of the sampler. 

It was found that for best results the dye should 

first be dissolved completely in water. This was the 

second method used. Alkalies, such as lye, make 

the dye more soluble. The mixing of dye, lye, and 

water in pails before putting it in a stream worke4 

well if only one concentrated test was necessary to 

determine actual speed of passage. If the mixture was distributed evenly, this method worked for tests 

requiring dyeing throughout half-hour or hourly 

periods. 

-In the third method the dye and lye solution was 

poured into an ordinary hand-pumped 3-gallon orchard sprayer. This was adapted for use by theremoval of the small disc in the spray head which 

causes the spray. The sprayer then ejected a small 

stream having an effective range of 30 feet. The 

advantages are obvious for the dyeing of streams, 

6

Stabler, Herman, Fluorescein an aid to tracing wat'!m underground: 

U.S. Bur. Reclamation, The Reclamation Record, v"ol: 12,· no. 3, pp. 

122-123, March 1921. 

Fuller, M. L., and others, Underground-water papers: U.S. Geol. 

Survey Water-Supply Paper 160, pp. 73-85, l!,t'J6. 

Meinzer, 0. E., Outline of methods for estimating ground:-water 

supplies: U •. S. Geol. Survey Water-Supply Paper 638-C, pp. 99-144, 1931. 

Wenzel, L. K., Methods for determining permeability of water• 

bearing materials: U. S. Geol. Survey Watel'-Supply Paper 887, pp. 72-74, 

1942. 
sinkholes, or even larger bodies of water. One charge, 

using a pound of dye, a pound of lye, and 2 gallons 

of water will dye a 6, 000 qallon-pel'-minute stream 

for 25 or 30 minutes. 

The fourth method used was for diamond drill holes, 

drilled at the surface or underground. As it was not 

always possible for a geologist or engineer to supervise 

the dyeing of drill holes the apparatus shown in figure 1 was made for use·by the driller. Iil use the upper 

valve is opened, the cylinder filled with dye, and the 

valve is closed. If the drill enters a cavity and 

loses drill water the driller shuts off his machine, 

opens the relief valve, and closes the cut-off valve. 

The drain valve below the cylinder is also opened to 

allow the water to drain from the. hose, and then is 

closed. Then the lower valve on the dye apparat-us is 

opened and the column of the water pipe is allowed to 

fm with dye, after which the valve is closed. With. 

the closing of the relief valve·and opening of the cut-

-eff valve the dye is forced into the hole under pres- sure. The driller then sends his helper to notify the 

nearby mine efH.eials to start sampling in the mine. 

Samplini. - Reliable results may be expected onl_y 

if sazilpfes are taken carefUlly arid at regUlar interVa.lf. 

In the procedure used, one man made a circuit of the 

sampling places each hour, taking samples of the water 

and noting the time each was taken. Racks containing 

sets of 24 one-irich pyrex test tubes 1~ fuches in 

length were used. Corex tubes of ultraviolettransmitting glass, which were not available at the 

time, should be used if possible. Each rack was numbered, corresponding to tbe place used, and the 

corks in the tubes were painted with consecutive 

numbers to avoid copfusion on recapituiation of sam- pling results. The sampler generally was not the same 

person who oriqinally dyed the water, thus dye pollution from clothes, boots, and hands was avoided. 

If t11e same person had to do both jobs, he changed 

clothes and examined his hands under the Mineralight before sampling, to avoid pollution and subsequent 

error iii the results. Records of all tests included 

time of dyeing, rate of flow in stream, time the dyed 

sample first appeared, relative strengths of dyed 

samples, and time the dyed samples stopped appearing. 

Use of ultraviolet light. - The Mineralight was used 

to detect fluorescein in all samples. Occasionally 

the dye was strong enough to be seen with the unaided 

eye, but this was unusual. The sampling was started as soon as the dye had been introduced into a stream 

suspected 'to be leaking into a nearby mine. The best 

procedure was first to dye the full length, of such a stream from a point at its head. This insured that 

the most distant points of access of water had been 

dyed, and therefore that the maximum travel time 

from stream to sampling point was determined. The 

samples were taken to a perfectly dark place, and were best viewed by holding the Mineralight over the 

mouth of the container. If the Mineralight was held 

against the side of the tube most of the ultraviolet 

light was reflected, refracted, or absorbed by the 

glass and a dilute solution containing dye could not 

be recognized. With the light over. the mouth of the 

tube the fluorescein emits visible light in all directions 

and the resultant zone of light is seen easily. The 

added depth of sample allows identification of more dilute solutions. Experience with the use of the light 

develops proficiency in the recognition of minute 

quantities of dye. With the type of samples taken in 

this study the unaided ey.e was unabl' to determine 

concentrations of less than 1 part in 50 million but 

with the aid of the light 1 pa.r1; in 40 billion was visible 

in the tubes. It is estimated that under the most 

favorable conditions, namely, a still deep pool in an 

underground stream, solutions as dilute as 1 part in 

200 billion could be recognized by holding the Mineralight over the pool. A viewing box for daylight exam- illation may be easily constructed with apertures· for 

the insertion of the light and specimen and for observinq the effect of the ultraviolet light. This method 1s 

not as accurate as the use of a place where the eyes can become accustomed to complete darkness. 

Comparative-flow method 

Weirs were ..iJ:istalled underground for the purpose 

of measuring rates at which water entered a mine. 

By the use of several weirs it was possible to apportion the total flow into rates of flow from each 

section and level of the mine. Surface weirs at the 

end of the pump-discharge lines gave a check of both 

pump capacity and of the total flow at underground 

weirs. Hydrographs of discharge showing the rates 

of flow for the mine and for each weir were made 

from measurements takenat 24-hour intervals over a 4- to 6-week period in each place. These curves, 

when correlated with rainfall curtes, gave a check on the laq in time between rainfall and the maximum 

increase of flow in the mines. Information regarding time required for transmission of the pressure 

effect caused by adding water, as compared with 

travel time of the water itself, was gained by adding 

volumes of water and dye simultaneously at one entry 

point. 

A study of 6 years' records of one mine was made 

because of the construction of a large flood-control 

and power reservoir in a nearby river valley. Geologic conditions indicated no direct subsurface con- nection between mine and lake. The curves for 

daily rainfall, pumping at the mine, and lake levels, 

when superimposed, showed that after the closing 

of the gates of the dam the pumping volumes were much greater during the wet winter season. The 

water table rose along' the sides of the valley as the 

lake filled. During periods of excessive rainfall the 

water table would normally rise temporarily, and the 

resultant surplus water would then drain into the river 

through springs. When the reservoir became filled 

this water would not drain off as readily, and the 

water table rose above the level of the mine workings. 

This rise in the ground-water level probably explains 

the large increase in volumes of·water pumped during 

the times of heaviest precipitation. Application of 

the weir method is discussed in the description of 

mine studies further on in this report. · 

Other methods of tracinq flow 

Some variations· of methods of tracing the flow of 

underground water are the use of sodium chloride or other salts, alkalies, bacteria, radioactive materials, 

and other dyes, detected by appropriate analytical, 

electrical, or visual methods. J/ 7 Cllurchill, M. A., personal communication, 1946. 

Wenzel, L. K., op. cit. 
Increase in the concentration of chloride created by 

the addition of large quantities of salt may be detected 

quickly and simply. Samples must be collected at the 

probable underground ~ource and a check made on the 

natural chloride content prior to the use of this method. 

Preliminary tests may indicate that a natural condition exists, such as surges of chloride-charged water 

released from flood-control dams, which may allow 

.sampling without raising the chloride content artificially. The relative concentrations are plotted on 

curves and compared for similarity with native water. 

Alkalies can be used in the same manner as salts. 

Measurements of electrical conductivity of the solutions may be used to detect the presence of greaterthan-normal concentrations of electrolytes. 

Another method applicable to the field would be t.he 

introduction of small amounts of radioactive materials 

into the water to be studied. Samples of the solution 

containing such material would· then give positive reactions when tested with a Geiger counter. 

Other dyes such as methyl umbelliferone {blue) and 

rhodamin (red) could be used and the sampling procedure would be the same as that used with fluorescein 

dye. 

Maps 

The records of all test work included a set of maps 

which show mine workings, drill holes, and streams, 

sinkholes, and other topographic features. All pertinent data relating to dyed localities, leaks, points of 

entry of dye into mine, and direction of flow between 

points were plotted. Significant geologic data were entered on these maps, and sections were made showing in three dimensions the solution channels in the 

rocks. 

Records 

Rainfall records, daily and hourly, were maintamed 

in permanent form,- together with all other records 

such as rates of flow over weirs, times at which flow 

occurs, daily volumes· of water entering and leaving , areas, and pumping records of 'IIlines by totals, .levels, 

and areas. The engineers used these records for reasons other than water problems, such as checks of 

pump efficiency and studies of ditch capacities. 

Applications 

The above techniques were applied in the studies of 

four different mines described below. 

Mine A.-An underground stream fed directly into the 

worEiiijS of mlne A, and attempts were made to determine something about the nature of the stream itself. 

A hole in a stream bed 5, 200 feet upstream from the 

mine portal was proved, by means of a dye test, to 

have a direct connection with this mine; so in a subsequent test 150 gallons per minute of water was divez:ted 

into the hole and at the same time this water was dyed 

with fluorescein. Constant ·watch at a weir in the mine 

showed that 30 minutes was required for the pressure 

effect to register, whereas 7 hours 48 minutes was required for the dye to appear. The difference in 

elevation was 130 feet. Research by the Hydraulic 

Data Division of the Tennessee Valley Authority has 

shown that a short time of wave travel and a much 

6 

longer period for the actual passage of the water, in 

any given section of stream, ditch, or pipe, indicates 

that a high percentage of this body of water is . pool. 

The above data were turned over to Mr. Churchill of 

the Hydraulic Data Division, who, by comparing these· 

figures with those for known streams, estimated an 

average cross section of 7. 48 square feet for this 

stream. He also estimated that 90 percent of the 

length of the stream might be pool. Later exploration 

proved this estimate to be correct. 

Flash floods in· the mine o1ten resulted in flows increasing from 300 gallons per minute to 15, 000 gallons 

per minute. An interpretation of rainfall and flow 

data showed this water to be ente+ing the ground over an area of some 825 acres, not directly over the mine, 

and then finding its way through a cave system to the 

mine. No preventive method could be used at the source. The safety factor of knowing when flooding 

would occur was important, however, and examination 

of the correlation of rainfall and flow curves revealed 

that, under conditions of maximum overburden saturation, ·the mine water would start to rise 2 hours after 

the beginning of rainfall. Depending upon the amount 

of rainfall, the mine would be flood-=cl. 6 to 8 hours 

later. By keeping a close check on rainfall the operators would thus have time to move men and equipment 

before mining became too dangerous. 

Sinkholes, as well as deep dry gullies, were tested 

by adding dye during periods of heavy rain. This dye 

showed up in the mine in from 50 to 70 hours after it 

was p~t into sinkholes 2 miles from the mine. 

A large creek flowed near the mine, and geologic 

evidence led to the belief that leaks from the creek 

contributed directly to the mine water. ·A discharge 

profile of the stream was made on the basis of a series of discharge measurements and two places 

were discovered where there were measurable losses 

in volume. These were checked with dye, and a direct -connection. was shown between these places and 

... the inine. This is a quick and economical method of 

locating leaks of more than 100 gallons per minute in 

small streams. A. 0. Patterson of the U. S. Geolocical Survey, who made the discharge profile, estimated a 5 percent limit of error in the determinations 

of stream flow, which ranged from 650 to 2, 000 gallons per minute. 

Mine B.-During heavy rainfall a sinkhole on mine 

B property collected a large amount of water which 

gradually drained into the ground. A comparison of 

surface and underground maps indicated that a heavily 

oxidized fault zone in the· mine would, if projected, 

pass through the sinkhole. Much water came into the 

mine along this fault. Flourescein dye was added to 

the stream of water flowing into the sinkhole during a heavy rain, and the leaks along the fault were checked 

underground with the Mineralight. The dye came 

through from the surface in 4 hours. The flotation 

process was used at this mine for milling ore, and 

the water for the milling came from the mine. Afte1· 

this water had passed through the mill the surplus was discharged into a ditch which carried it to the 

sinkhole described above. It w~ suggested that 

elimination of this recirculation of water would save some pumping expense. In 1948, a storm sewer was 

constructed to carry discharge from this mill beyond 

the sinkhole and into a creek, ~o that the water no 

longer recirculated. 
Mine c.- Mine C was the largest mine dye-tested 

during this investigation. It consists of 125 acres of 

stoped ground in gently dipping beds. The workings 

extend from the surface to a depth of 1,000 feet. Here," 

measuring the flow of the water was made complex by 

very erratic distribution of ditches, which necessitated 

the installation of several weirs. In addition, three 

main levels contributed water to these ditches. Water 

pumped from the lower level was added to that from 

the upper levels. The times of pumping for the lower 

level varied from day to day, and a separate record 

of these was maintained. Checks made every 24 hours 

for a month revealed a lag of 4 hours between heavy 

rainfall and entry of the excess· water into the uppermost level; this lag seemed to increase proportionately with depth. The short time of transit indicates .the 

open, or cavernous; condition of the ground. The · weir discharges were plotted individually on a common sheet, using a different color for each weir, and 

another curve represented the total discharge for the 

mine. 

Normally dry sinkholes were tested by introducing 

fluorescein dye during heavy rains, but all tests were negative. However, many sinkholes remain to be 

tested and these should show some positive results. 

Dye tests were made in the major streams and the 

water-plant canal. In one stream, which had already b~en partly lined with reinforced concrete, a test 

showed a leak just below the lower end of the lining 

which, when time-tested with dye, carried water to an 

upper level of the mine in 45 minutes. This leak was temporarily blocked by diverting a stream of tailings 

into this section of the creek, but a reinforced concrete 

pad over the danger area would provide a permanent 

remedy. 

A large river flows over part of the mine, and it was thought that this river might contribute heavily to the 

mine water. A test was made when the river was flowing at the rate of 6,000 cubic feet per second 

(nearly 3,000,000 gallons per minute). Thirty pounds 

of dye was used and this allowed a continuous test over a 1-hour period. The dye was found in the s,amples 57 hours later, after it had traveled 3 miles 

downstream, dropped 500 feet along fractures and a tear fault into the mine, and returned to the sampling 

point through one intermediate sump and along 7,500 

feet of ditch. The dye was not visible to the unaided 

eye in this test. 

During the tests at this mine a set of 5 racks, holding 24 tubes each, was employed. One man made the 

rounds every hour and the actual time needed for a 

complete. circuit of the route was 30 minutes. Four 

men, including a relief man, did the work on a 24-

hour basis for 5 weeks and checked weir readings at 

.the same time. The total cost of the labor for the 

period was $20.40 per day and $737.00 f~r the job. 

The sampler gathered up all the racks after the last 

sample and brought them to the shaft where they could 

be examined by the geologist or engineer and dumped 

before he started his next round, ·making. it unneces- sary to provide two racks for each sample point. 

Mine D.- Mine D was the last mine studied, and although the work was not completed, many new facts were learned. Results of the work proved that direct 

connections existed between a nearby creek and the 

mine, and some of these were blocked later. New 

7 

methods were used for accurately dyeing sections of a flowing stream. The possibiUty of dyeing drill holes 

was studied, and an apparatus was devised for the introduction of the dye into the holes. A study of topography and subsurface qeology indicated zones that 

might prove to be most favorable for the passage of 

underground water. 

The mine prodqces a volume of water far out of proportion to its size, and if this condition increases the 

mine will become uneconomical to operate,· as pumping costs will exceed profits. Influx of .ground water 

at this mine due to the raisinq of the water table by 

construction of a dam nearby has been discussed earli- er in this paper. The topoqraphy· over the mine is 

much like that at the other mines, but the mine•water 

problems are more difficult becaus~ there is no surface 

drainaqe above the mine except through sinkholes. 

However, 2,000 feet south of the mine a larqe creek crosses the formation in which the mine is located. 

This stream emerges from one spring area which has 

flowed at rates ranging from 1, 500 to 80,000 qallons 

per-m'inute, depending on the seasonal rainfall. 

This creek was dyed .at its source and dye was found 

in the mine by means of the Mineralight in 8 hours. 

The next step was to survey the stream in sections 

200 feet in length, and plot these points on a map. 

Then dye tests were made of each section, starting at 

the lower end and working upstream until the dye was found in the mine. This method succeeded only until one test was positive, for dye introduced upstream 

from this point would have come into the mine through 

this same point. Steps were taken to isolate the leaking area. The water in this section was diverted and 

the holes were located, and closed by grouting and 

other concrete work. Closing the holes proved to be 

unsuccessful, for the water soon found new openings. 

However, diversion of the stream proved to be suc- cessful, for dye tests of the diverted section show:ed no leaks and the tests were resumed upstream. SUch 

a procedure can be carried on at little expense until 

the extent of the cavernous, area is determined, and 

then an over-all program·, such as flume or pipe, 

grouting, or concrete-pad work, can be planned and 

carried out. 

• Floods occur during many periods of the year and an attempt was made to simulate the conditions produced by' floods. A Parshall measuring flume was installed .. in the mine; lack of head and large amounts 

of slimes prohibited the use of another kind of weir. 

The surface stream was diverted from sections of its 

bed containing known leaks. Then water was turned 

into these sections and a close watch was kept for an increase in flume readings, which came in 12 hours. 

Another plan was to dam a section of the stream, 

causing low flood lands along the creek to be covered 

with water. This was accomplished by installing 

temporary wooden gate~ on culverts which carried the 

creek under a railroad spur. The water presslll'e 

held them in place and, as the creek had a very slight 

fall in this section, ·within 24 hours a foot of water 

backed up over the area to be tested. The rise in the 

flume reading in the mine was noted at the end of the 

period. Dye tests during this period showed that water came from the stream into the mine. During the tests on this creek the sprayer described earlier proved 

very successful because of its long effective range, its 

economical use of dye, and its portability. 
These tests also indicated that a large volume of 

water, not connected with the creek, came from another source. When all known creek openings were blocked a considerable amount of water continued to come into 

the mine. Also, some leaks in the mine never con- tained dye even though others did. 

A program was devised to study possible channels of 

-flow. The apparatus described above for use with the 

diamond drill (fig. 1) was made to introduce the dye, 

and it was planned to test each cavity encountered in 

drilling- checking points of entry, time of flow, and 

relative strengths of dye sampled. A chart was kept 

of all results, and this will ultimately show the paths 

of flow between certain cavernous areas and the mine. 

Careful study has shown that a possible solution of the 

problem of a particularly "wet" block of ground might 

be the laying down of a grout curtain through the same drill holes. . · 

8 

·The company controlling this property followed all 

work closely, assigning a special geologist or enqineer 

to observe and cooperate on all operations. They propose to continue the work on a yearly basis, followinq a plan drawn up as a result of the above studies. 

CONCLUSIONS 

The above methods were used to trace the flow of 

qround water in the area around the mines described. 

The dyeinq and comparative-flow techniques provide a cheap, rapid, and effective means of determininq the sources and routes of travel of troublesome mine water 

in cavernous limestone and dolomite terrain. The aid 

;these methods qive in directinq· preventive measures far. outweiqhs the cost of makinq a survey. Some of 

the techniques employed miqht be easily adapted to 

studies of mine-water problems under different geoloqic conditions. 
Lo~r Yt~~lv, 

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FIGURE 1 

APPARATUS FOR INTRODUCING DYE INTO 

DIAMOND DRILL HOLES 

70Jf7