Selected Techniques 

in Water Resources 

Investigations, 1965

GEOLOGICAL SURVEY WATER-SUPPLY PAPER 1822
Selected Techniques 

in Water Resources 

Investigations, 1965

Compiled by GLENNON N. MESNIER and EDITH BECKER CHASE

GEOLOGICAL SURVEY WATER-SUPPLY PAPER 1822

Papers on new techniques by J. S. Bader, 

R. N. Cherry, 0. J. Cosner, J. H. Criner, 

M. J. Fishman, J. R. George, H. P. Guy, 

N. R. Harmon, E. R. Hedman, L. S. 

Hughes, E. J. Kennedy, F. A. Kilpatrick, 

R. A. LeBlanc, E. D. Lucero, ff^. T. 

Miller, C. G. Mitchell, J. C. Mundorff, 

fF. D. Peterson, D. Pettengill, R. J. 

Pickering, J. P. Richardson, ff^. D. 

Robbins, G. ff^. Sandberg, P. R. Seaber, 

R. J. Smith, L. G. Toler, J. Fecchioli, 

J. IF. IFark, and H. B. Wilder

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1966
UNITED STATES DEPARTMENT OF THE INTERIOR 

STEWART L. UDALL, Secretary

GEOLOGICAL SURVEY 

William T. Pecora, Director

Library of Congress catalog-card No. OS 66-205

For sale by the Superintendent of Documents, U.S. Government Printing OfiBice 

Washington, D.C. 20402 - Price 45 cents (paper cover)
CONTENTS

Page 

Introduction__________________________________________ 1

Enclosed bubble-gage orifice systems, by Edward J. Kennedy__________ 3

Purging bubble-gage orifice line with self-contained air-pressure spray

can, by Wallace D. Robbing.. ___________________________________ 10

Stream-gaging equipment for high altitudes, by Wallace T. Miller and

Joe P. Richardson_______________________________________________ 13

The acoustic signaling box a current-meter accessory, by Robert J.

Smith._________________________________________ 21 

Deluxe top-setting wading rod, by W. Don Peterson___________________ 26

Construction of stream-gaging wells using steel oil drums, by Elizardo

D. Lucero________________________________________________ 31

Construction of low-cost ground-water observation wells, by Olive" J.

Cosner and F. A. Kilpatrick______________________________________ 34

Electrical water-level measuring reel, by Raoul A. LeBlanc.____________ 38

Device for removing debris from wells, by J. S. Bader__________________ 43

Device for remote recording of fluid-level fluctuations, by J. H. Criner__ 46 

Ice-prevention system for gage wells, by Dale PettengilL _______ ________ 50

Ice auger, by Dale Pettengill________________________________________ 53

Tipping hanger for current meter and sounding weight used for discharge

measurements under ice cover, by E. Robert Hedman_______________ 56

Filtering water samples using vacuum from automobile windshield wiper,

by Hugh B. Wilder..______________.______________ 59 

Filtering water samples using vacuum from automobile intake manifold,

by Neal R. Harmon______________________________________________ 61

Installation assembly for conductance cells, by L. G. Toler and R. N.

Cherry.____________________________________-_-__-----_____-_-_- 63

Use of thermistor-thermometer in determination of specific conductance,

by Leon S. Hughes---____-__--___-___-___--_--_-_____-------_-_- 66

Spectrophotometric determination of aluminum using Eriochrome Cyanine

RC, by Marvin J. Fishman___________________________________..___ 70

Semimicroanalytical method for the determination .of iodide in wfter,

by C. G. Mitchell. ____________________________________________ 77

System for monitoring fluvial sediment, by H. P. Guy_____-_-__-____-_- 84

Single-bottle sampling in operation of a sediment station, by J. R. George

and J. W. Wark________________-________---_--_-_--------_--__-_ 89

River-bottom sediment sampling with a Swedish Foil Sampler, by R. J.

Pickering____________________________________--__----_______---- 94

Sediment deposition from atmospheric precipitation, by James C.

Mundorff _____________________._--____-__.___._------_ 100

Use of soil-consolidation test data to determine permeability of clays,

by Paul R. Seaber and John Vecchioli___________________---__---__- 105

Two simplified variations of a method for computing ground-water pumpage, by George W. Sandberg_____________-______________-___--__-_ 114

ITI
SELECTED TECHNIQUES IN WATER RESOURCES 

INVESTIGATIONS, 1965

COMPILED by GLENNON N. MESNIER and EDITH BECKER CHASE

INTRODUCTION

Increasing world activity in water-resources development has created an interest in techniques for conducting investigation? in the 

field. In the United States, the Geological Survey has the responsibility for extensive and intensive hydrologic studies, and the Survey 

places considerable emphasis on discovering better ways to carry out 

its responsibility. For many years, the dominant interest in field 

techniques has been "in house," but the emerging world inte^st has 

led to a need for published accounts of this progress. In 1963 

the Geological Survey published "Selected Techniques ir Water 

Resources Investigations" (Water-Supply Paper 1669-Z) as part of 

the series "Contributions to the Hydrology of the United States." 

The report was so favorably received that successive volumes are 

planned, of which this is the first.

The present report contains 25 papers that represent new ideas 

being tested or applied in the hydrologic field program of the Geological Survey. These ideas range from a proposed system for monitoring fluvial sediment to how to construct stream-gaging wells from 

steel oil drums. The original papers have been revised and edited 

by the compilers, but the ideas presented are those of the authors. 

The general description of the bubble gage on page 2 has been given 

by the compilers as supplementary information.
THE BUBBLE GAGE GENERAL DESCRIPTION

The bubble gage was developed by the Geological Survey for 

making a continuous record of the evaluation of a water surface. The 

bubble gage measures the elevation of a water surface by sensing 

pressure above an orifice submerged in the body of water of which 

the elevation is being determined. Pressure head of water at the 

orifice is transmitted by a gas-purge system, through flexible polyethylene tubing, to a servomanometer that operates a continuous 

water-stage recorder. Nitrogen gas from a storage cylinder in the 

recorder shelter feeds into the pressure system and bubbles slowly 

from the sensing orifice. The pressure at the orifice, and hence in 

any part of the system, is related to the head or depth of T^ater over 

the orifice.

The bubble-gage eliminates the stilling well needed for operation 

of conventional float-operated water-stage recorders and substitutes 

the flexible pressure tubing for the more costly inta,ke pipes. 

Because the gas-purge pressure system is open to the atmosphere, the 

problems found in many older types of closed pressure systems 

for measuring and transmitting water-surface elevations have been 

eliminated.

The gage structure for a bubble gage can be a simple rhelter (to 

house the servomanometer, the water-stage recorder, and the nitrogen 

gas cylinder) placed so the flexible pressure tubing can be run to the 

point for which the record of water-surface elevation is needed. 

Elimination of a stilling well and of rigid intake pipes reduces the 

cost of building the gage structure, and gives a wide choice of sites 

at which a recording gage can be located. Because of the flexible 

tubing the orifice can be moved readily if the streambed or channel 

shift, and even the entire gage installation can be moved at nominal 

cost.

The bubble gage is described in more detail by E. G. Barron in 

U.S. Geological Survey Water-Supply Paper 1669-Z. Solutions to 

problems that have occurred in actual field operation of the bubble 

gage are given in the present report by E. J. Kennedy (p. 3) and 

W. D. Bobbins (p. 10). 

2
ENCLOSED BUBBLE-GAGE ORIFICE SYSTEMS

By EDWARD J. KENNEDY

ABSTRACT

Excellent records of stage of streams whose channels are subject to severe 

scour and fill can be obtained by using bubble gages equipped with enclosed 

orifice systems. An enclosed orifice system consists of a probe which contains 

an orifice, a well screen, and a flushing device, and a minature stilling veil above 

the probe. The bubble gage measures variation in hydrostatic pressure of ground 

water at the probe near the stream. The measured changes in ground-water 

head are virtually identical to variations in stream stage where geo^gic conditions are favorable. Where conditions are unfavorable, the orifice system can 

sometimes be modified to collect adequate records.

BUBBLE GAGE

A bubble gage for recording river stage uses gas forced slowly 

through an orifice at a fixed underwater location. Pressure necessary 

to bubble tho gas is directly proportional to head of water over the 

orfice. That pressure is measured by a self-balancing mercury manometer. Manometer displacement is registered in units of gag^ height 

on a recorder. The operation of the bubble gage was described by 

Barron (1963, p. Z4 Z9). The unique ability of the bubble gage to 

measure water-surface elevation inside an extremely small well is 

the principal feature that permits use of the orifice system d^cribed 

here.

CONVENTIONAL STILLING WELLS

Most gaging wells designed for use with float-operated water-stage 

recorders are at least 36 inches in diameter to permit entry for maintenance. Free transfer of water between stream and well, usually by 

intake pipes, is vital to satisfactory gaging operation. Scour and fill 

of stream channels often make intakes impractical because the pipes 

are alternately covered with bed material or left dry above tr°s water 

surface. Sometimes, under favorable circumstances, such wells can

3
4 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

be operated satisfactorily by seepage of water through the bed material 

between stream and well. These wells are subject to a certain amount 

of lag in time before water-surface elevations inside the w41 and in 

the stream equalize. Lag may be large or small depending on such 

factors as rate of change of stage, surface area of well, permeability 

of bed material, and distance from well to stream.

MINIATURE STILLING WELLS

Surface area of a circular stilling well varies with the square of its 

diameter. A 1-inch well has only about Visoo the surface area of a 

36-inch well and all other factors being the same, would have only 

y13oo °f the lag of the larger well. Wells as small as one-half inch in 

diameter can be used with bubble gages.

The principal element of the enclosed bubble-gage orifice system is 

the probe. The probe, basically an intake for a miniature stilling 

well, is installed near or under an alluvial streambed. Details of a 

typical probe and orifice are shown in figure 1. The components are 

mostly 114-inch pipe and standard fittings.

Water enters and leaves the probe through a well screen whose mesh 

dimensions are not critical. Plastic or stainless-steel well screens are 

less prone to clog than the more common bronze screens. However, 

some polyethelene orifices become sealed in a few months by buildup 

of bacterial deposits. Copper tubing is not similarly affected. A much 

simpler orifice and screen than that shown in figure 1 migl t be satisfactory in some streams.

The part of the probe between the well screen and the pipe cap is 

a return pipe for flushing. (See fig. 1.) To flush the proto a pitcher 

pump is substituted for the pipe cap, and water is pumped slowly from 

the well until the discharge is clear. Flushing is rarely necessary 

where probes are buried deeply enough to remain covered at all times. 

The flushing procedures is a simple and excellent test of communication between river and probe as well as an effective way to flush both 

the well screen and the bed material near it.

The joints in the well pipe should be water tight to prevent entrance and circulation of unfiltered river water. The pipe must also 

serve as an escape patch for gas purged by the bubble gage. The gas 

carries away moisture that otherwise would condense inside the pipe, 

and might freeze and cause back pressure and faulty record. The 

problem is most serious in wells smaller than % inch in diameter.

Antifreeze, usually kerosene, is poured into both sides of the Ushaped probe (fig. 1) for winter operation. The orifice mu?t be below 

the bottom of the floating kerosene column to avoid nonlinear datum
ENCLOSED BUBBLE-GAGE ORIFICE SYSTEMS

PROBE DETAIL OF ORIFICE 

INSIDE PROBE

-Bubble tube

IVi" pipe

Tee and cap for flushing 

and adding antifreeze

Water surface

Antifreeze

" '. Sandy bed 

:.'-' material

: Orifice 

^ (detail at right)

3A" square brass stock 

notched at corners 

and self-threading

Male connector 

" tube 17 Vi" pipe

-IVi" coupling

Male connector 

W tube to Vi" pipe

 Vi" copper tube

^Orifice 

FIGURE 1. Details of probe and enclosed bubble-gage orifie.

errors. This position is obtained by keeping the orifice below the top 

of the well screen openings. Excess kerosene will escape through the 

well screen into the bed material.
6 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965 

LOCATION OF PBOBE

A convenient location for a probe is at the downstream side of a 

bridge pier. The pier makes a firm and protected support. A probe 

can usually be buried deeply by jetting, and it is not seriously affected 

by drawdown and turbulence behind a pier. Figure ZA illustrates 

such an installation in its simplest form. Deep burial (3-10 ft) is not 

always practical. Shallower probes are usually placed in a nearly 

horizontal position similar to the one in the typical bank installation 

shown in figure 2B. A pier installation requires the shortest length 

of watertight pipe because it need only extend to the pier top. A 

bank installation generally uses pipe, rather than light conduit, all 

the way to the shelter and consequently costs more to build. Firm 

anchorage of at least the lower end of the intake pipe is vital. Vertical 

movement of the probe causes a datum error in the stagv record. 

Earth anchors screwed deeply and firmly into the bed material are 

excellent supports for probes and pipes. In rocky material, steel 

fence posts make satisfactory anchors. Heavy U-bolts can be used 

for rigid connection of pipe to anchors. Gradient of a well installed 

on a bank must provide for drainage of condensate and other water 

from the pipe so that the escape path for purged gas will net become 

blocked.

Water-tight 

well pipe

FIGURE 2. Typical installations of an enclosed orifice bubble-gape system. 

A, Pier installation; B bank installation.
ENCLOSED BUBBLE-GA/GE ORIFICE SYSTEMS 7 

GEOLOGY AND GROUND-WATER CONSIDERATIONS

The gage measures ground-water head at the probe which may or 

may not vary directly with stream stage. If the ground water moves 

with appreciable velocity, a corresponding hydraulic gradient is 

present. If the gradient, distance from probe to streambed, and duration of water movement are large, the relation of aquifer head to 

surface-water head may not be equivalent for long periods of time.

The geology of the deposits underlying a gage site is the most important factor affecting accuracy of records obtained from enclosed 

orifice systems. Conditions are best where bank storage is least and 

permeability of bed material is high. A channel cut deeply in a deposit 

containing material of low permeability overlain by material of relatively high permeability provides ideal conditions for installation of 

an enclosed orifice system. Such a site is illustrated in f gure 3A. 

A probe located almost any place in the sand would perform well. 

A similar channel in clay without the overburden of higher permeability requires some modification of the site. Material around the probe

Relatively

impermeable

material

Relatively impermeable material

FIGURE 3. Examples of (A) favorable and (B) unfavorable geologic 

conditions for use of enclosed orifice system.
8 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

can be excavated and replaced with sand. If the clay is extremely 

tight, a sand-filled trench across the stream may be necessary.

Figure SB illustrates a channel in a wide sandy valley. Storage 

capacity is large in the wide aquifers bordering the channel. Each 

change in river stage is accompanied by substantial ground-water 

movement for long periods of time as the stream is alternately influent 

or effluent. Records collected using a probe of usual design p,nd location would be dubious. At such sites, recorded graphs are usually 

similar in shape to those based on outside gage readings but fluctuations 

are seriously dampened in magnitude. A rise and fall of 3 feet in 

river stage may be recorded as only a 2-foot rise and fall, yet recorded 

time of peak will be correct. To minimize such error, several techniques may be used. The downward movement and mos4^ of the 

horizontal movement of ground water, with resulting head loss, may 

be stopped by concrete slabs, plastic membranes, or metal containers 

under the probe. Varying degrees of success for varying lengths of 

time may be expected. An extremely shallow position for the probe 

and frequent flushing might be considered a more practical solution to 

this problem by operating personnel.

Streams underlain by alternate layers of permeable and impervious 

material are the most difficult to gage with the enclosed orifice system. 

Each layer can have an artesian head substantially different from that 

of its neighbors. None is likely to have head variation ver<T closely 

related to change in river stage. Probes used at these sites should be 

nearly horizontal and within inches of the streambed.

CONCLUSIONS

The enclosed bubble-gage orifice system has merit where geologic 

conditions are favorable. It is also worthy of consideration where 

open bubble-gage orifices in streams are adversely affected by high 

velocity or turbulence or where ice and debris damage is common.

Where geologic conditions are somewhat less favorable, other considerations are applicable. Most stage records are collected to use in 

computing discharge data. The stage-discharge relation for a scouring-and-filling alluvial channel is rarely stable. A stage record that 

contains errors no larger than the usual amount of rating shift between 

successive discharge measurements is adequate for computing 

discharge.

When geologic conditions are definitely unfavorable, the enclosed 

orifice system should be considered with serious reservations and in the 

light of possible alternatives. However, ingenuity and resourcefulness are vital ingredients in adapting new equipment to unusual 

conditions.
ENCLOSED BUBBLE-GAGE ORIFICE SYSTEMS 9 

LITERATURE CITED

Barron, E. G., 1963, New instruments for surface-water investigations, ir, Mesnier, 

G. N., and Iseri, K. T., compilers, Selected techniques in water resources 

investigations: U.S. Geol. Survey Water-supply Paper 1669-Z, p. Z1-Z12.
PURGING BUBBLE-GAGE ORIFICE LINE WITT:I SELFCONTAINED AIR-PRESSURE SPRAY CAIT

By WAIXACE D. BOBBINS

ABSTRACT

A satisfactory solution to the problem of removing oil, moisture, or other 

foreign material from bubble-gage orifice lines has been devised. The procedure 

makes use of an inexpensive commercial self-contained air-pressure sprayer 

adapted to connect directly to the orifice line. Volatile organic solvents are 

sprayed into the line to clean it.

INTRODUCTION

In the operation of bubble gages, oil, water, or other foreign material very often become trapped in the polyethlene tubing between 

the sight feed and the orifice. This material clogs the tube and 

causes pressure to build up in the line. When the pressure becomes 

great enough to move the material and unclog the line, gas will begin 

escaping, and as the pressure is reduced foreign material will again 

clog the line. This alternate clogging and unclogging of the line 

produces an abnormal condition at the manometer. This condition 

can usually be detected by examining the strip chart which will show 

an abnormal fluctation, or false surge caused by the r^anometer 

pressure-sensing system. One of the solutions to this problem is to 

purge the orifice line with volatile organic solvents such as lacquer 

thinner or white gasoline.

DESCRIPTION OF SPRAY CAN

An inexpensive self-contained air-pressure spray can nmy be used 

in purging the orifice lines. This can may be purchased from automotive- or janitor-supply dealers, and can easily be adapted for this 

purpose. Figure 1 shows the difference in the pressure spray can 

as purchased commercially and as altered for use on orfice lines. 

The can on the left (before) has a small factory-built spray nozzle

10
PURGING BUBBLE-GAGE ORIFICE LINE 11

u

FIGURE 1. Self-contained air-pressure spray can before and after alteration for 

use on orifice lines. X, Factory-built spray nozzle; Z, nozzle altered to 

attach directly to the orifice line; Y, %-inch brass tube fitting.

(X) ; the can on the right (after) has been altered at point Z to 

attach directly to the orifice line. A %-inch brass tube fitting (Y) 

can be tapped and threaded to screw directly to the existing fitting on 

the spray can after removing the spray nozzle.

PURGING PROCEDURE

Recommended field procedure when purging is necessary is as 

follows:

1. Pour about one-half cup of lacquer thinner or white gasoline into 

the spray can.

2. Fill the spray can with air from a service-station pump or with

gas from the bubble-gage supply. 

A. If service-station air supply is used, remove the valve cap from

the top of the can and inject air at this point. 

B. If service-station air supply is not available, pressure can be 

obtained from the bubble-gage gas supply by the following 

method: (a) close the sight-feed needle valve; (b) close 

the feed-pressure adjustment screw; (c) remove the polyethlyene brass tube connecting the regulator and sight feed,
12 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

and screw the tube directly to the spray can; (d) open feedpressure adjustment screw to about 55 pounds, press down 

on spray-can trigger and allow pressure between regulator 

and spray to equalize; (e) release trigger, close feed-pressure adjustment screw, and remove spray can from the line. 

3. When the spray can has been filled, take the following steps:

A. Attach spray can directly to orifice line and spray contents of 

pressure can into orifice line.

B. Remove spray can from orifice line, and hook orifice line directly to pressure regulator (bypass sight feed).

C. Release gas directly into orifice line, setting pressure adjustment screw on regulator at about 55 pounds, and let it run 

for 2-3 minutes. This procedure will dry any remaining 

lacquer thinner or gasoline from orifice line.

D. Reinstall all tubes and connections in working order. (Note: 

Care should be taken when opening feed-rate adjustment 

needle that more oil is not blown into the line.) 

This procedure takes 5-10 minutes. Usually it will take another 

5-10 minutes before bubbles begin to come out of the orifice.
STREAM-GAGING EQUIPMENT FOR HIGH ALTITUDES

By WAIJ^ACE T. MILLEB and JOE P. RICHARDSON

ABSTRACT

Reliable gage-height records and stable stage-discharge relations were obtained 

from stream-gaging stations at high altitudes during severe winter weather. A 

bubble-gage water-stage recorder driven by a negator spring was used to eliminate 

the problem of frozen stilling wells and intakes. The stream controls, either 

artificial or natural ones, were covered and heated to keep them free of ice.

INTRODUCTION

There are 90 gaging stations in Colorado above an altitude of 8,000 

feet; 19 of these are above 9,000 feet and 1 is above 10,000 feet. It 

is practically impossible to operate many of these stations with conventional stream-gaging equipment during the severest part of the 

winter season because of inaccessibility or extremely low temperatures. 

Lack of accurate winter records at such high-altitude stations has 

not been considered serious because only 10-15 percent of the annual 

runoff occurs during this period and variation in flow is small. However, most of the storage sites at low altitudes in Colorado have been 

developed and additional storage reservoirs must be at high altitudes. 

Consequently, the need for better and more complete streamflow 

records at high altitudes is increasing.

During the summer of 1960 the Watershed Management Unit, 

Colorado State University, began a comprehensive study in the South 

Fork Cache la Poudre basin. Accurate streamflow records, complete 

for all of the year, at altitudes above 9,000 feet were desired.

SELECTION OF SITES

The Colorado Water Conservation Board cooperated in installing 

and operating 3 gaging stations. Two of the sites selected are on 

Little Beaver Creek, one at 10,000 feet (drainage area 1.8 sq mi),

13

2
14 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

and the other at 8,350 feet (drainage area 13 sq mi). The third 

station is on Fall Creek immediately below a large beaver pond at 

9,770 feet (drainage area 3.7 sq mi).

PROBLEMS

The basic problems at any stream-gaging station are to be able to 

obtain a continuous gage-height record and to have a stable relation 

between stage (gage height) and discharge. At high altitudes, gageheight records are difficult to obtain because conventional stilling wells 

and intakes freeze. Accumulation of snow and ice on the stream 

controls (either natural riffles or artificial-control structures) disrupts 

the stage-discharge relation.

To obtain the gage-height records needed the plan finally adopted 

was to use bubble gages driven by negator springs. The bubble gage 

does not need a stilling well because it operates without a recorder 

float. Intake pipes are not needed because a gas-filled tube, that 

will not freeze, running out to the stream serves as the intake. The 

recorder is driven by a negator spring instead of by clock weights, 

which must have a well in which to travel downward; the use of the 

negator spring eliminates a secondary need for a stilling well.

On small streams, gaging stations are ordinarily located upstream 

from a well-defined riffle that will act as a stage-discharge relation 

control and also form a pool in which the intake can be placed. At 

sites where a suitable natural riffle cannot be found, an artificial 

control some type of flume or low dam is built. At two of the 

stations discussed here artificial controls were built, and at the third 

a natural riffle acts as the stage-discharge control.

The stream controls were protected from snow and ice by building 

roofs or covers over them, using propane heaters under the covers, 

and hanging curtains from the covers to keep the heat in. The heating system was adapted by the senior author from a system devised 

by the U.S. Forest Service for heating stilling wells in the Fraser 

Experimental Forest.

A secondary but important problem with stations at high altitudes 

is accessibility. The upper Little Beaver Creek site is 0.8 mile from 

the nearest road or trail. An access road suitable for jeeps or trucks 

was built; the road was graded with a D-4 dozer to the grade and alinement established by the Forest Service. The other two sites are accessible by improved roads.

SHELTERS FOB WATER-STAGE RECORDERS

The instrument shelter used on upper Little Beaver Creek is about 

4 feet square and 8 feet high, and is made from sheet metal. This 

installation is shown in figures 1 and 2.
STREAM-GAGING EQUIPMENT, HIGH ALTITUDES 15

FIGURE 1. Stream-gaging station at upper Little Beaver Creek 

site with winter cover removed from the artificial control. 

Instrument shelter is in the background. V-notch is in place in 

the Parshall flume.

Shelters for the water-stage recorders on lower Little Beaver Creek 

and Fall Creek are made from 6-foot sections of 42-inch diameter 

corrugated galvanized-metal culvert pipe and have conical metal roofs. 

The shelter on Fall Creek is shown in figure 3.

CONTROLS AND COVERS

A 4-foot Parshall flume was installed at the upper Little Beaver 

Creek station. A removable steel plate with a 90° V-notch was installed in the flume at the throat to increase the accuracy at low flows 

and to create a deeper pool over the orifice in case an ice cover should 

form that far upstream from the weir plate (fig. 1). The plate is 

%6-inch steel, 18 inches high, and the bottom of the notch is 0.52 foot 

above the floor of the flume. The plate was bolted to a removable 

angle iron frame attached to the flume. The entire V-notch assembly 

can be removed easily, even during high flows. However, it is planned 

to remove it each year before the spring high water.
16 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

FIGURE 2. Stream-gaging station at upper Little Beaver Creek site with V-notch 

plate removed from the artificial control and one panel of the cover in place 

over the control.

FIGURE 3. Stream-gaging station at Fall Creek site, 

place over the natural rock control.

Cover is in
STREAM-GAGING EQUIPMENT, HIGH ALTITUDES 17

The cover for the artificial control of the upper Little Beaver Creek 

station is formed of panels 32 inches wide and 5 to T feet long, laid 

side by side across the flume. Framing for each panel consists of three 

2- by 6-inch planks running lengthwise on 16-inch centers with a 2- by 

6-inch member spiked across each end. A layer of 65-pound roll 

roofing was laid on top of the framing, next 1-inch thick wooden 

sheathing was nailed in place, and then a layer of 65-pound roll roofing was put on top of the sheathing to complete the panel. The 

panels can be installed or removed readily. Heavy canvas curtains 

attached to the upstream and downstream ends of the cover form an 

enclosure for the flume. The bottom edges of the curtains are attached 

to a pole to hold them in place. A stock tank-type butane burner 

costing1 $17 is attached to the underside of the upstream cover panel. 

The burner is described in the sales catalog1 as a "15-inch burner with 

safety shut-off and shield"; it is not thermostatically controlled but is 

equipped with a shut-off valve that will close automatically if the 

flame is extinguished. The burner is supplied from a 300-gallon 

storage tank equipped with a gage graduated in percentage of tank 

capacity.

A self-cleaning concrete artificial control (fig. 4) was constructed 

at the lower station on Little Beaver Creek. The floor of the flume is 

10 feet long and 16 feet wide. The flume is 20 feet wide at the top of 

the 4-foot walls. There is an ogee drop in the floor of the flume. The 

crest of the ogee section is a gentle V. Width of the flume at the top 

of the ogee crest is 17.13 feet, and elevation of the crest drops from 

1.15 feet above the floor at the walls to 0.3 foot above the floor in the 

center of the flume, which is the bottom of the V.

The cover over this control consists of three steel ceiling joists 21 

feet long set across the walls of the control on about 5-foot centers 

(fig. 5). These joists are the type commonly used in concrete building 

construction for floor or ceiling joists. Joists are available for various 

spans and loadings, and it is a simple matter to compute the load and 

select the proper joists.

Wooden panels 3 by 10 feet, similar in construction to those just 

described for the upper Little Beaver Creek station, were placed over 

the steel joists. Heavy canvas curtains were hung at the upstream 

and downstream ends of the cover.

The heating unit at this station is a 12,500 Btu radiant propane 

burner equipped with a 100-percent shutoff valve, self-generating pilot 

light, and an automatic temperature gage (thermostat) that ranges 

from 0° to 70° F. (See fig. 5.) The cost of this burner was $275. 

It is supplied from a 500-gallon storage tank that has the same type 

of meter as the one at the upper station. The burners, canvas aprons,
18 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

FIGURE 4. Self-cleaning concrete artificial control at lower 

Little Beaver Creek site with cover removed.

and covers at both stations are removed before the spring runoff. 

High flows at this station can be measured from a footbridge temporarily constructed at the upstream edge of the apron from two of the 

joists braced together and two of the cover panels laid lengthwise on 

top for a floor.

The Fall Creek station is at an excellent natural rock control about 

10 feet downstream from a Forest Service deck bridge. The control 

is in the shape of an irregular U and is 2^ to 3 feet high and 3 to 7 

feet wide. There is a deep pool under the bridge, ideal for the bubble 

orifice.

Natural conditions are quite favorable at this location and it was 

decided not to install a heater, so comparisons could be made between 

the heated and unheated installations. However, a cover and canvas 

curtain similar to those at the other two stations were installed (fig. 3).

Because conditions at the bridge were poor for making accurate 

discharge measurements, a shore-operated cableway was installed at 

an excellent cross section a short distance downstream. With this 

equipment the current meter is suspended from a carrier riding on 

the main cable. The operator on the shore can move the carrier to 

any position and raise or lower the meter at will.
STREAM-GAGING EQUIPMENT, HIGH ALTITUDES 19

FIGUKE 5. Concrete flume used for the artificial control at lower Little Beaver 

Creek stream-gaging station. Cover is in place but roofing material and canvas 

curtains have not been installed. Note propane burner attached to underside 

of joists.

COST OF INSTALLATION AND OPERATION

Installation costs are itemized in table 1. As expected, installation 

costs were substantially greater than for an average gaging station 

on streams of this size. Annual operating costs are about $1,700 for 

each station.

TABLE 1. Installation costs

Item

Materials: 

Gage 

Cable, shore-operated _ _ _

Supervision: Salary and per diem_ __

TotaL _ _ _ _

Fall Creek

$1, 380 

80

120

440 

295 

200

2,515

Little Beaver Creek

Upper 

station

$1, 590

265

115 

900 

635 

590 

330

4,425

Lower 

station

$1, 370 

175

505

825 

880 

525

4,280
20 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

BESULTS

The heating equipment operated much better than we had even 

hoped. It took a little time to get the burners adjusted but during 

the winter, when they were most needed, they functioned very satisfactorily. The unregulated burner at the upper Little Beaver station 

burned continuously. The only adjustment made was the amount of 

gas to the burner. The initial gas supply lasted from November 3 

to May 31.

It is very gratifying to read the hydrographer's notes which usually 

said, "Stream completely snow and ice covered, no ice in flume or Vnotch, burner OK."

Adjustment of the heating system at the lower Little Beaver Creek 

station took longer. The thermostat was first set too low. The original setting, on November 4, was about 40° F, and on November 16 

it was increased to 50° F. On January 16 the pool above the control 

and under the cover was partly ice covered, but open in the center 

under the burner. Ice built up below the notch, causing 0.02 foot of 

backwater. The chart indicated that the bubble orifice had been frozen 

for about 2 weeks. The thermostat was turned up to 62° F on that date 

(Jan. 16). Subsequently, the burner functioned satisfactorily and 

notes on the chart read "no ice effect" or "control clear." Mud covered the orifice several times, but otherwise an excellent record was 

obtained. Forty-eight percent of the gas supply of 425 gallons was 

used from November 4 until the flame went out, probably blown out 

by the wind, sometime between visits on April 17 and May 22,1961.

On Fall Creek, the cover and curtains without a heater proved 

to be ineffective. Ice soon bridged over the entire stream, under the 

cover as well as in the open. A radiant propane burner was installed 

in September 1961, and winter operation since then has been satisfactory.

Perhaps such elaborate installations cannot be afforded at every iceaffected station. However, winter streamflow data were needed for 

this project and the results obtained justified the additional expense. 

These investigations demonstrated that accurate winter records can 

be collected at high altitudes if conventional stilling wells and intake 

pipes are eliminated and if the control in the stream is covered and 

heated.
THE ACOUSTIC SIGNALING BOX A CURRENT-METER

ACCESSORY

By ROBERT J. SMITH

ABSTRACT

The acoustic signaling box in various forms has been used by several U.S. 

Geological Survey offices and other agencies for counting the revolutions of a 

current meter when measuring stream velocity or discharge. These boxes, particularly a new transistorized oscillator-type, offer many advantages over the 

conventional earphone attachment. Several models developed by a power company in California were field tested. Commercial units that can be purchased are 

described.

INTRODUCTION

Current meters are usually equipped with a battery-operated electrical circuit that produces a signal at each revolution or fifth revolution of the rotating cups or vanes. In the conventional meter assembly 

the signal is carried to a telephone receiver at the ear of the observer, 

and the observer determines stream velocity by counting and timing 

the signals or "clicks" he receives in the earphone. The acoustic signaling box described in this report is a modern device that substitutes for 

the earphone in the current-meter assembly. This box is essentially 

a transistorized audio-oscillator attached to a miniature speaker and 

powered by a mercury pen-light battery. Its light weight, low cost, 

and ease of assembly are obvious advantages. The Pacific Gas and 

Electric Co. Water 'Systems office in San Francisco, Calif., has developed two types in the past 4 years which have been tested in field use 

by personnel of the Geological Survey.

An acoustic signaling box does not have the undesirable features 

of the earphone currently used by hydrologists. Fieldmen find the 

discomfort of the earphone pressure on the head and ears irritating. 

The dangling wire from the earphone to the wading rod, or to the 

reel when the meter is cable-suspended, is often in the way. During 

a wading measurement the dangling wire interferes with field note

21
22 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

computations, and during a bridge measurement the wire hampers the 

fieldman in his movements to watch for floating drift or to measure 

the angle of the current. The earphone is a particular annoyance when 

a canal measurement is made from a low footbridge with the meter 

attached to a pipe. At that time the observer must use a long extension wire or he must fasten the earphone to the top of the pipe, 

from where it is difficult to hear the meter clicks.

Throughout the years,'Geological Survey fieldmen have used various 

approaches to improve methods of counting current-meter revolutions. 

These methods have included bicycle horn buzzers, telephone company testing units, and hearing-aid adapters. This article deals only 

with the oscillator-type acoustic receiver, commonly called a "beeper." 

This name refers to the peculiar beeping sound the receiver emits, one 

that is well, known to radio "hams" when they use code to send and 

receive messages. The high pitched "beep" emitted by the speaker is 

more audible than the "click" sound of the earphone.

PACIFIC GAS AND ELECTRIC CO. ACOUSTIC SIGNALING BOX

Two types of beepers have been designed and developed since 1960 

by the Pacific Gas and Electric Co. The first unit was made in 1960 

from a code practice oscillator kit. The wiring was somewhat complicated for those not familiar with electronics and although the unit 

was reduced in size, it was still too heavy for use on a wading rod. 

Three flashlight batteries were used and the total weight was more 

than 2,y2 pounds. The most attractive feature of this model was a 

volume control which permitted the beep to be amplified so it could 

be heard above the sound of heavy traffic on a bridge. The original 

model is still being used (1964) and there have been no failures in 

the electronic circuitry.

Using the Pacific Gas and Electric Co. design as a guide, the author 

built a smaller unit in 1961 for field use by the U.S. Geological Survey. 

The parts were fitted into a rectangular box 6% by 3% by 2% inches 

and a telephone plug was installed so the beeper could be plugged into 

the top of a Geological Survey top-setting wading rod. The weight 

was reduced to 20 ounces by eliminating some parts and using only 

one battery. Because the box was not watertight, a plastic bag was 

placed over the beeper during rainstorms to eliminate the possibility 

of short circuits in the wiring. There was very little muffling of the 

sound caused by the bag.

A new model was developed by the power company hydrologists in 

1964 which appears to have additional favorable features. It is cheap, 

easy to put together, and has the major advantages of light weight 

and a lesser susceptibility to damage from shock than the two models
ACOUSTIC SIGNALING BOX 23

described in the preceding paragraphs. The audio-oscillator is 

mounted on a iy2- by 1%-inch circuit board. The Calrad miniature 

0.05-watt speaker is % inch thick and 1% inches square, and the battery holder for a 4.5-volt mercury battery is % by % by 2V4 inches. 

The standard female phone plug in use by the Geological Survey was 

assembled with the other parts on a piece of vinyl tile so that the assembled parts would fit into a plastic cigarette box. (See fig. 1.) 

Total cost of the beeper was only about three-fourths the present cost 

of an assembled earphone. The new beeper weighs only 8 ounces and 

is small enough to be carried in a shirt pocket.

FIGURE 1. Acoustic signaling box, 1964 model, assembled 

to go into plastic box cover.

The three beeper models described above have been field tested by 

both power company and Geological Survey employees since 1960, and 

all who have used them prefer the beeper to an earphone. Figure 2 

shows the 1964 model plugged into a top-setting wading rod and 

figure 3 illustrates how the unit may be used with a three-wheel crane 

and reel during bridge measurements.

COMMERCIAL SIGNALING BOXES

Signaling boxes manufactured by A. Ott Co. of Bayern, Germany, 

are the only ones known to 'be available for purchase in the United 

States. The Ott model F2 is both a visual and acoustic device in a 'box 

51/2 by 3^4 by 2% inches. Each revolution of the current meter is 

announced by a buzzer signal and a small flashing light. The F2 may 

be used with a wading rod but was not designed for use where the box 

is not in close proximity to the meter. This model uses two flashlight 

batteries and weighs 21 ounces.

The Obfc model F4 counter box is not of the acoustic type, but records
24 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

FIGURE 2. 'Signaling box plugged into top-setting wading rod.

FIGTJBE 3. Signaling box (A) attached to crane and reel used for discharge 

measurements from bridge.
ACOUSTIC SIGNALING BOX 25

F2

F4

FIGURE 4. Ott signaling boxes F2, F4, and F6.

each turn of the meter on a counter. It is housed in a 24-ounce box 

that is 6% 6 by 314 by 2 inches.

The Ott model F6 is a combination acoustic and counting device. 

It is designed for use in measuring flow where the counter is a great 

distance from the current meter and would be useful in measuring 

some of the wide, deep rivers in the United States where a poweroperated reel is used. The 'box is 7% by 5 by 5% inches and weighs 

6 pounds.

These commercial units range in cost from eight to thirty times that 

of the 1964 model designed by Pacific Gas and Electric Co.

The three types of German-made signaling boxes are shown in 

figure 4.

SUMMARY

Transistorized oscillator-type signaling boxes offer many advantages 

over the conventional earphone for counting revolutions of a current 

meter. The signaling boxes are light weight, easily assembled, and 

more convenient for use than earphones. Furthermore, they can be 

produced for a price equivalent to or cheaper than assembled earphones. They may eventually replace earphones for general field use 

with current meters.
DELUXE TOP-SETTING WADING ROD

By W. DON PETERSON

ABSTRACT

The Price-type current meter is used to measure stream velocity when discharge measurements are made at the more than 8,000 stream-gaging stations 

operated by the Geological Survey. At low stages a wading rod is generally 

used to support the current meter and to measure stream depths. The standard 

wading rod used for many years was a ^-inch-diameter round rod made by 

joining 1-foot sections which were equipped with threaded ends. The round, 

jointed wading rod has gradually been replaced by a 4-foot hexagonal top-setting 

rod. By using the top-setting rod, the hydrographer can place the current meter 

at the proper depth for observing water velocity without touching any wet 

parts of the rod or meter and without removing the meter from the water. A 

scale on the handle of the top-setting rod indicates, for any observed depth, the 

correct meter setting for taking velocity readings at 0.6 of the observed depth. 

The author modified the top-setting rod to a deluxe model that contains penlight batteries in the handle of the rod to supply current to the electrical circuit 

of either the conventional headphone, a transistor-type light-weight headset, or 

an acoustic signaling box.

The Geological Survey, in cooperation with State and other agencies, measures streamflow at more than 8,000 stream-gaging stations 

in the United States. At a typical gaging station a continuous record 

of gage height is observed and the discharge of the stream is measured 

often enough during each year to determine a relation between gage 

height and discharge. The Price-type current meter is used to 

observe stream velocity as part of the procedure of making discharge 

measurements. On the smaller streams and also during periods of 

low flow on many larger streams the hydrographer takes the observations of velocity, depth, and width, which are needed to make a 

discharge measurement, by wading across the stream. During a wading measurement the current meter is supported on a wading rod, and 

the stream depths are measured by using graduations on the 

wading rod.

The standard wading rod used for many years is a ^-inch-diameter 

round rod made in sections a foot long that can be connected by

26
DELUXE TOP-SETTING WADING ROD 27

threaded joints on the ends to'assemble them into a unit of whatever 

length is needed. A base plate keeps the rod from settling into the 

bed of the stream. The Geological Survey has developed another 

type of wading rod, the top-setting rod, and is rapidly changing to 

the use of it. (See fig. 1.)

The top-setting rod is made of a 4-foot length of i/^-inch hexagonal 

stainless-steel rod, graduated in feet, and tenths, that has a round base 

plate attached to the bottom end and an aluminum casting, 6*% 

inches long, on the top end which serves as a handle. The current 

meter is supported on a fitting, called a "double-end hanger," that 

slides freely on the hexagonal rod. A 57-inch length of %-inch

B

FIGURE 1. Wading rods and Price-type current meters. 

A, %-inch-diameter round rod assembled from 1-foot 

lengths; B, top-setting wading rod. Headphone circuit 

with battery fastened to telephone jack is plugged into 

handle of the rod.
28 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

round stainless-steel rod extends upward from the hanger and passes 

through guide holes at the top and bottom of the aluminum handle. 

The %-inch rod is parallel to the main hexagonal rod and % inch 

behind it. A friction catch near the top of the handle will hold the 

small rod and the double-end hanger and current meter at any desired 

depth for velocity observations. With the top-setting rod it is not 

necessary to remove the rod and meter from the water to make the 

setting for depth, or to handle any wet equipment. A grounded 

telephone-type male plug projects from the top of the handle. The 

small rod is insulated from the double-end hanger, and the main rod 

is insulated from the handle. A lead wire extends from the small 

rod to the meter contact wire, and an enclosed wire extends from the 

top of the main rod to the insulated element of the male plug. A 

female jack in a separate circuit containing a battery and an earphone 

is placed over the plug on the handle of the rod to complete the equipment needed to count the revolutions of the current meter.

Another feature of the top-setting wading rod is that it has graduations, on the small rod and the aluminum handle, arranged so that 

when the rod is raised until the graduations read the same as the total 

depth, the meter is positioned at 0.6 of the total depth below the water 

surface. For depths of less than 2 feet, a velocity reading at 0.6 

depth corresponds to the mean velocity in the vertical.

The author has modified the top-setting wading rod and produced 

a deluxe model (fig. 2) which holds two pen-light batteries, in the 

hollow handle of the rod, to operate the signal circuit. Special electrodes inserted at the top have been adapted to receive either the 

standard telephone-type male plug or a %-inch-diameter transistor 

radio female jack.

To produce the deluxe rod, the male telephone plug was removed 

from the aluminum handle of the rod. The hollow part of the handle 

was reamed out with a %6-inch drill bit to a depth of 5y2 inches to 

accommodate two pen-light batteries and a small spring. The male 

telephone plug was replaced with an adapter that makes contact with 

the upper battery. The small spring rests on the top end of the 

hexagonal rod and extends into the handle to make contact with the 

lower battery. Alkaline batteries give the best service.

The upper end of the %6-inch hole drilled in the handle was 

threaded with a %-inch NF tap, and received an adapter machined 

from %-inch round brass stock. The adapter was the only complex 

piece of equipment needed and had to be produced on a lathe. The 

handle of the rod contains an insulated brass plug which makes contact
DELUXE TOP-SETTING WADING ROD 29

FIGURE 2. Handle of deluxe top-setting wading rod. A, 

Handle holds two pen-light batteries; B, adapter screws 

into top of handle so male transistor plug can be used 

in headphone circuit.

with the center electrode of the upper battery and receives the transistor earphone plug. A slightly different adapter is needed if the 

telephone-type male plug is to be used on the handle of the rod. The 

handle of the modified top-setting wading rod having adapters for use 

with the two types of plugs in the headphone circuit is shown in 

figure 3.

This system for signaling revolutions made by the current meter is 

rugged and most convenient. It is exceptionally trouble free and has 

been giving fieldmen excellent service. The transistor earphone is 

not cumbersome, and gives excellent service and performance. The 

hydrographer is scarcely aware of the electrical equipment except for 

the clear signals received. Comfortable and convenient equipment 

to be used by the hydrographer, especially in inclement weather, will 

result in better quality discharge measurements.

796-504 O «6 3
30 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

Interchangeable electrode adapters

Telephone-plug adapter, " diameter transistor 

telephone plug in 

headphone circuit

Transistor telephoneplug adapter

1 INCH

-W hexagonal stainless-steel rod

round stainless-steel rod

FIGURE 3. Handle of top-setting wading rod showing changes made to convert 

to the deluxe model. A, Hollow handle was reamed enough to hold two penlight batteries; B, adapter to use with headphone circuit having male transistor telephone plug; and C, adapter to use with headphone circuit having 

female telephone jack.
CONSTRUCTION OF STREAM-GAGING WELLS USING 

STEEL OIL DRUMS

By ELIZABDO D. LTTCERO

ABSTRACT

The problem of obtaining a practical and economical substitute for conventional materials to use in building stream-gaging wells was solved by using 

steel oil drums. Construction of gage wells from steel drums is especially adaptable for installations on bridge piers and for short-term and portable gaging 

stations.

INTRODUCTION

In 1957 the U.S. Geological Survey in cooperation with the Government of Puerto Kico began an investigation of the water resources 

of the island. Material for gage wells for stream-gaging stations had 

to be imported because local distributors did not stock pipe. Nestable 

corrugated metal pipe was used for bank installations because it is 

obtainable in semicircular sections 2 feet long; in this form it is easily 

transported at low freight costs. However, nestable pipe is not suited 

for installations placed directly in the stream, such as those attached 

to bridge piers, because of the excessive expense involved in sealing 

the joints to reduce surge in the well. To avoid the expense of shipping fabricated pipe, 55-gallon oil drums, obtained locally, were used.

CONSTRUCTION

Drums in good condition were selected and the ends were burned 

off. Short sections were assembled in the shop by welding two drums 

together. Each section was painted completely with red-oxide paint 

and then with aluminum paint. An alternate process to inhibit corrosion is to paint the drums with zinc shield, which is best applied 

with a spray gun. Zinc shield contains 95 percent metallic zinc and 

serves as a substitute for dip galvanizing. The zinc shield is probably 

superior to red-oxide paint and is only slightly more expensive.

In the field the two-drum sections were assembled into a complete 

unit and the joints were welded. A final coat of paint was applied

31
32 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

to cover the welds and scuffs received during transportation and erection. Vertical bracing was added for increased strength against floods 

and hurricanes. The two stations constructed using the oil-drum gage 

wells proved to be satisfactory in every respect and are shown in figure 1. The station (fig. 1Z?) on Rio Guamani near Guayama, Puerto 

Kico, recorded an outstanding flood having a peak flow of 20,000 cubic 

feet per second and survived without damage.

FIGURE 1. Stream-gaging wells in Puerto Rico constructed from oil 

drums. A, Typical installation on Quebrada (Creek) Cimarrfin 

near Jobos; B, lower section of well, intake pipe with static tube to 

reduce drawdown, staff gage, and low-flow channel on Rio Guamani 

near Guayama.
CONSTRUCTION, STEAM-GAGING WELLS, OIL DRUMS 33

Following the successful adaption of the 55-gallon oil drums to 

gage-well fabrication, small portable gaging stations were later installed using grease drums 14 inches in diameter. These gages were 

of sufficient size to accommodate a water-level recorder having an 

8-inch float.

Since the experiment in Puerto Rico, oil drums have been used in 

construction of gaging stations in the Virgin Islands.

COST

Table 1 presents 1961 costs of comparable gaging stations constructed using nestable corrugated metal pipe and steel oil drums.

TABLE 1. Comparative cost of stream-gaging wells

Material used

Nestable corrugated pipe. 

Size of well

Diameter 

(in.)

21

24

Length 

(ft)

40 

40

Cost (dollars)

Pipe

222 

42

Erection

140 

70

Welding

180 

46

Fainting

16

30

Total

667 

188

PRECAUTION

Cutting steel drums with an oxygen and acetylene torch can be 

hazardous if proper precautions are not observed to prevent the possibility of explosion of fumes from combustible residues in the drum. 

Before.the drums are cut, they should be rinsed and steam cleaned 

and the bungs removed. A welding torch should not be used to cut 

any drum that has contained particularly explosive substances.
CONSTRUCTION OF LOW-COST GROUND-WATER 

OBSERVATION WELLS

By OLIVER J. COSNEE and F. A. KILPATRICK

ABSTRACT

In a study to determine the source of base flow of Piedmont streams in 

Georgia, 40 obervation wells 10-50 feet deep were drilled at a cost of $3.50 

per foot. This cost includes $2.00 -per foot for drilling and $1.50 per foot for 

materials and their installation by Geological Survey .personnel. This low cost 

resulted from hiring the cable-tool drilling on an hourly basis, using Geological 

Survey personnel for supervision of drilling and placing of casing and screens, and 

using suitable low-cost materials not ordinarily used in wells.

In the fall of 1961 a study was made to determine the source of base 

flow of streams in the Piedmont of Georgia. Part of this investigation was the observation of ground-water levels throughout a river 

basin. Forty temporary observation wells ranging from 10 to 50 feet 

in depth were drilled to bedrock. The base-flow study was completed 

in 1963, but other hydrologic studies, in which the same observation 

wells were used, were continued in the area.

The typical cost for constructing observation wells is about $5-$6 

per foot. However, for this project a cable-tool drill rig and crew 

drilled the wells for $2 per foot. Survey personnel supervised the 

drilling, logged and sampled the holes, and installed the casing. In 

this manner the wells were constructed at a total cost of $3.50 per foot.

Design of the wells is shown in figure 1." Twenty-six gage, 6-inch 

diameter galvanized crimp-joint stovepipe in 10-foot lengths ($0.40 

per foot) was used for the casing, and 6-inch-diameter, 3-foot-long 

galvanized perforated sheet metal rolled into stovepipe ($1.00 per 

foot) was used for the screens. The screens fit together in the same 

manner as the stovepipe casing and are interchangeable with it (fig. 2).

The jig shown in figure 3 was designed to assemble the screens and

pipe over the hole. The jig was necessary to aline and to hold the

pipe while it was being assembled and to prevent it from falling into

the hole. While the pipe was clamped in the jig, four to six

34
CONSTRUCTION, GROUND-WATER OBSERVATION WELLS 35

Pop rivet

Backfill, / 

dry soil/

Backfill, 

pea gravel

0,.................lQi

^ii::;:::::::^ 

t*tt±'. Jftt.ffM ."Jtr 

tf:::»:::::f(:::K

i^

 Well casing 

6" x 10'sections

-Well screen 

6"x 3' sections

FIGURE 1. Sketch of well construction.

holes were drilled with a hand drill around the circumference at the 

joint, and the two lengths of pipe or screen were secured with pop 

rivets.
36 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

FIGURE 2. A, Well screen (6-inch by 3-foot perforated galvanized sheet metal) ; 

B, 6-inch galvanized casing (6-inch by 10-foot 26-gage stovepipe) ; C, 4-inch 

fiber soil pipe casing; and D, pea gravel for packing around screens in wells.

A pop riveter is a small hand tool with a plier grip. It holds a 

single rivet that is inserted in the hole through the two pieces of pipe 

to be joined. The rivet is made fast by squeezing the grip. A pop 

rivet gives a strong, clean joint having no protrusion inside the casing. 

The rivet is secured entirely from the outside and does not require 

holding or backing inside the pipe. Other types of fasteners such as 

metal screws usually leave protrusions inside the casing which obstruct 

floats and other equipment lowered into the well.

When the drill crew completed the hole to the proper depth the jig 

was placed over the hole and the screen and casing were lowered as 

each joint was fastened. Pea gravel, one-half inch in diameter, was 

placed around the screen and the lower few feet of casing. Where 

runny sand and silt strata were penetrated, an 8-inch steel casing was 

placed as drilling progressed. The 6-inch stovepipe casing was set 

inside the 8-inch casing and the 8-inch casing was removed as the gravel 

packing was added. After placement of the gravel, the well was 

bailed to clean out mud and to determine well capacity. At this point 

the drill rig moved on to the next hole.

The annular space between the 6-inch casing and the hole, above the 

gravel pack, was back filled with earth. In some wells, drilling mud 

was used for this purpose; however, the mud built up hydrostatic
CONSTRUCTION, GROUND-WATER OBSERVATION WELLS 37

FIQTJKE 3. Well casing and screen being assembled in a 

jig over well. Geological Survey employee is using the 

pop riveter.

pressure on the casing and caused complete collapse of the casing in 

three holes.

A more rigid type of casing is needed if drilling mud is used for 

back filling, or if casing is to be placed in loose wet silt or sand above 

the water table. Fiber soil pipe (fig. 2(7) proved satisfactory in casing some shallow flood-plain wells. This fiber pipe is available in 2-, 

4-, and 6-inch diameters ($2.90 per 4 inches by 10 feet). Also available is 4- and 6-inch diameter rigid plastic sewer pipe ($3.90 per 4 

inches by 10 feet). An additional advantage of the fiber soil pipe and 

of the plastic sewer pipe is that they both are joined with a special friction fit and cemented coupling that is water tight.
ELECTRICAL WATER-LEVEL MEASURING REEL

By RAOUL A. LEBLANC

ABSTRACT

The need to decrease maintenance of water-level-measuring equipment constructed of wood and obsolete parts was met by designing an all-metal unit. The 

new reel weighs less, is constructed of parts easy to obtain, and uses a smaller 

diameter electrode and cable than the former unit. In addition, an accessory 

easyover to protect the cable was improved by a grooved sheave and cable guides. 

The new unit is dependable and easy to operate.

INTRODUCTION

During ground-water investigations, measurements often must be 

made to water deeper than 500 feet below land surface, to waiter surfaces obscured by falling water, and to water surfaces that are 

changing rapidly. Steel tapes are impractical to use under these 

conditions; consequently, electrical equipment was developed.

One of the first electrical water-level units designed and used in the 

author's area was made of a wood carriage together with militarysurplus parts, including a spool, bushings, a copper-tubing handle, a 

cable, and a separate meter. A compact 15-pound unit has been 

developed (fig. 1) to replace bulkier, heavier makeshift units.

DESCRIPTION OF THE UNIT

The present model consists principally of two parts, a carriage and 

a spool fabricated from i/8- and %6-inch aluminum plate. The carriage is 12 inches high, including handle, and 18 inches long. The 

carriage has been equipped with self-alining bearings to assure smooth 

operation and ease in replacing spools of cable. The bearings allow 

angular movement of the i/^-inch stainless-steel shaft when replacing 

a spool, and they allow the cable to pay out freely of its own weight, 

as the electrode is lowered into a well. The crank on the shaft is 

reversible for right- or left-handed operation.

38
ELECTRICAL WATER-LEVEL MEASURING REEL 39

3,3

FIGUEE 1. Electrical water-level measuring reel (A) 

and accessory easyover (B) at a well.

The spool is 9 inches in diameter, has a 4-inch core, and will hold 

more than 2,000 feet of %2-inch diameter cable. Each end of the 

spool has a stainless-steel flange and a key way that fits the shaft. The 

spool and the bearings are electrically insulated from the carriage and 

the ground.

The electrical components for the reel are on the spool and in the 

base of the carriage. The schematic wiring diagram of the reel is 

shown in figure 2. A 9-volt transistor radio battery and clip, a variable resistor with an on-off switch, and a 0-1 milliamp miniature edgewise panel meter (fig. 3) are installed within the carriage base. The 

0-20,000 ohms resistor may be set to accommodate the electrical resistance of water at each well measured to the deflection desired on 

the milliamp meter indicator. A ground wire with an alligator clip 

and a pin jack is attached to the circuit through an insulated plug in 

the base at the front of the carriage.

The spool usually carries 1,000 feet of cable marked in code at 10-, 

50-, and 100-foot intervals. One end of the cable is attached to the
40 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

To electrode

9 volts

0-20.000 fl

FIGURE 2. Schematic wiring diagram for the electrical water-level measuring

reel.

* V

\

FIGURE 3. Edgewise panel meter mounted on the carriage.

core of the spool and the other end to an electrode. The electrode is 

weighted with sections of lead tubing, and it has a tip protected by 

pliable plastic; maximum diameter of the electrode is three-eighths 

inch, so it can pass through small access holes. Use of a lightweight 

cable makes cranking 600 feet or more of cable from a well an easy 

task. This cable has a diameter of %2 inch and 4 copper and 3 steel 

strands of wire covered with a tough but pliable plastic.
ELECTRICAL WATER-LEVEL MEASURING REEL 41

To avoid cutting the insulation or the wire on sharp edges of the 

pumps or well casings, an easyover is used. An easyover is a metal 

rod with a grooved sheave and cable guides at one end (figs. 1 and 4) 

and a pair of prongs at the other.

OPERATION OF THE UNIT

At a well site, place the prongs of the easyover in the ground with 

the sheave over the access hole to allow the cable to ride free of sharp 

edges. Turn on the resistor switch on the right-hand side of the 

carriage. Attach the ground-wire alligator clip to the casing, pump 

unit, or wet-ground surface for contact. Allow the cable to run freely 

over the easyover sheave and down the well casing while holding the 

unit with one knee. When the electrode contacts the water, the needle 

of the meter will indicate the completed circuit by a positive deflection. 

Slowly retract the cable from the well and watch the meter. The 

break in contact between the electrode and the surface of the water 

causes a sudden drop of the meter indicator to zero. At this point 

grasp the cable at the measuring point and measure the distance on 

the cable to the first 10-foot marker below the measuring point. Add 

the length of the electrode and count the 10-foot intervals from the 

marker mentioned above to the first identified 100-foot or 0 marker 

to determine the depth to water.

FIGUBE 4. Sheave and cable guides on the end of the easyover.
42 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

When making pumping tests, water levels that are rapidly changing 

can be measured in hundredths of a foot by attaching a steel tape, 

graduated in hundredths of a foot, to a marker on the cable that will 

remain below the measuring point during the test. The measurements can be read directly from the steel tape by raising the electrode 

to and above the water surface at desired time intervals.

About 10 of these electrical water-level measuring units have been 

in field use for 4 years. The units have required only minor repairs, 

including the replacement of one milliamp meter.
DEVICE FOR REMOVING DEBRIS FROM WELLS

By J. S. BADEB

ABSTRACT

A grappling device, similar to a pair of ice tongs, has been designed and 

effectively used to remove debris from wells. Rehabilitating existing wells by 

using this device eliminates the cost of drilling new ones.

INTRODUCTION

A device, referred to by the designers as the "beartrap," is useful 

in removing a wide variety of objects such as blocks of wood, stones, 

cans, bottles, pipes, and poles from wells. This article describes the 

device and how it operates. It can be constructed from a simple sketch 

or from a photograph by a blacksmith, and no special talent is 

required to operate it.

DESCRIPTION OF THE GRAPPLING DEVICE

The grappling device consists primarily of two arms and two bars 

fastened together to allow the arms to open and close freely about a 

pivot, much like a set of ice tongs (fig. I A). The other parts are the 

locking bar, which holds the arms open, and the trigger mechanism 

(tripping rod), which closes the arms when the device is being used 

to grasp an object in a well.

The bottom ends of the arms are fitted with curved metal plates or 

serrated claws to grip and hold objects securely. The device is shown 

in the closed position in figure IB.

The small jointed locking bar (fig. 1C) holds the arms open when it 

is extended below center (slightly more than 180° as measured at the 

j oint of the locking bar). The locking bar is kept from moving farther 

downward by a tab which bears against it when the device is in the 

open position (fig. 1C). A tripping rod extends downward between 

the arms from the pivot point of the locking bar.

43
44 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

Locking bar 

Pivot point

Tripping 

rod

FIGURE 1 (above and facing page). Grappling device, or "beartrap," for removing 

objects from wells. A, Device in open position; B, device closed;
WELL-CLEANING DEVICE 45

Locking bar

C, detailed view of locking bar and releasing rod; D, "beartrap," gripping a

heavy object.

796-504 O 66 4
46 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

The device may be made in any desired size. Two sizes have been 

built and used successfully, one fitting into an 8-inch well casing and 

the other into a 10-inch casing.

OPEBATION OF THE DEVICE

In use, the device is cocked in the open position and lowered into the 

well on a suspension cable that is fastened to a ring. When the foot of 

the rod strikes the obstructing object in the well, the rod pushes upward on the locking bar, releasing it, and the arms are pulled together 

by a spring opposite the locking bar (fig. 1(7). Once the arms grasp 

an object, upward pull on the suspension cable causes them to clamp 

even more tightly. The weight of the object being lifted holds the 

arms together, and the heavier the object, the tighter they grip. The 

arms can be closed from above if the tripping rod will not close them 

in an appropriate position. A line tied to the rod at the pivot point 

of the locking bar can be pulled when the arms are in the desired position, and thus close them around an object without the aid of the rod. 

Figure ID shows how an object is gripped and held firmly. The 

projectile weighs about 15 pounds.
DEVICE FOR REMOTE RECORDING OF FLUID-LEVEL

FLUCTUATIONS

By J. H. CEINEB

ABSTRACT

The hazard of servicing gages that record fluid level at sites where, exposure 

to radiation or other danger exists can be avoided by using self-synchronous 

motors to operate recording gages at a location remote from the site of the fluid. 

The routine work of inspecting recorder charts, removing charts, and maintaining the recording gage can be performed at a safe distance from whatever 

hazard exists at the fluid for which the level is being recorded.

Disposal of liquid radioactive wastes by seepage into the ground 

generally requires the continuous recording of the fluid level in 

seepage pits and in nearby monitor wells. Information on fluid 

levels in the pits is needed for computations of the rate of seepage 

into the ground, of the volume of waste still remaining in the pits, 

and of the capacity of the pits to hold additional waste. Information 

on fluid levels in monitor wells is used in determining the configuration 

of the liquid surface and the rate and lateral direction cf liquid 

movement.

Recording gages can be installed before disposal operations are 

begun, but the subsequent replacement of charts and servicir g of the 

gages is hazardous if the time needed to do so results in overexposure 

to radiation. The remote recorder makes possible without danger 

of such exposure the recording of fluid levels at any site where 

radioactivity from liquid wastes poses a threat to healtl . It is 

equally suitable for installation in places not readily accessible for 

other reasons. Conceivably, the recording of fluid-level fluctuations 

at many widely scattered and remote points could be done at one convenient location.

In addition to a recording gage, each installation requires a pair 

of Selsyn (self-synchronous) motors, sufficient 3- or 5-wire cable to 

reach from the site of fluid-level measurement to the remote recording47
48 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

gage site, and a source of 110-volt a-c electric power (110-volt, 60-cycle 

alternating electrical current). One of the motors is a master, or 

transmitting, unit and the other is a slave, or receiving, unit.

The master motor is mounted on a platform over the point of fluidlevel measurement and, in places where radioactivity may be a hazard, 

is installed before any radioactive wastes are present. T e pulley 

(removed from the recording gage) is connected to the drive shaft 

of the master motor, and a float and counter weight are attached to 

the opposite ends of a cable passing over the pully. When in operation, the upward and downward travel of the float resting on the 

rising or falling fluid surface will drive the master motor.

The slave motor simply repeats the turning, in either direction, of 

the drive shaft of the master motor, and it does so with greater force 

than is required to turn the shaft of the master motor. A sleeve 

joint is used to connect the drive shaft of the slave motor to the drive 

shaft of the recording gage, and both the motor and gage are mounted 

firmly on a single platform at a convenient and safe distance from the 

site where the fluid-level fluctuations are to be measured. The transmission distance may be only a few feet or as much as several miles 

but, if more than a few hundred feet, boosters may be reiuired at 

one or more places along the line.

If a source of 110-volt a-c electricity is available at both sites and 

both master and slave motors are connected to it, the cable connecting 

the motors needs to contain only three wires. However, if a power 

source is available at the site of only one of the Selsyn motors, a 5- 

wire cable is needed to connect both motors to the electrical-power 

source. Where several field sites are near telephone lines, it may be 

possible to rent use of the lines for electrical connections of pairs of 

motors to centralize recording instruments in a convenient location.

At an Atomic Energy Commission installation near Oak Ridge, 

Tenn., fluid-level fluctuations in a "hot" waste-disposal pit were recorded on a drum-type weekly recording gage (fig. 1) situated a short 

but safe distance from the pit. The float was 2 inches in diameter 

and made of copper. The Selsyn motors were purchased at small 

cost from a company selling surplus military equipment and, although not needed for the 200 feet of connecting cable, boosters could 

have been obtained from the same outlet. Because a source of electricity was available at only the recording-gage site, 5-wire cable had 

to be used; it was relatively inexpensive and was installed by Survey 

personnel. Remote recording systems have been used for many years 

and at least one instruments company offers a system of the kind 

described here.
REMOTE RECORDING OF FLUID-LEVEL FLUCTUATIONS 49

Recording gage

110 volts ac

Liquid level in waste pit 

FIGURE 1. Remote operation of fluid-level recording gage.
ICE-PREVENTION SYSTEM FOR GAGE WEI/LS

By DALE PETTENGILL

ABSTRACT

Bubbling a compressed gas into a gage well near the bottom will keep ice 

from forming around the float during subfreezing temperatures. Gas from a 

pressure cylinder of nitrogen, equipped with a pressure regulator and needle 

valve, was fed through a hose to a small pipe that released the gas near the 

bottom of the gage well. The bubbling creates vertical currents which carry 

the warmer water to the surface and prevent the formation of ice.

In localities where subfreezing temperatures occur in tr^ winter, 

provisions must be made each autumn to keep the water in the gage 

well at a stream-gaging station from freezing. Ice can be prevented 

from forming by use of an insulated subfloor, by installation of oil 

tube for the float, or by bubbling a gas from the bottom of the well. 

Since the winter of 1959-60, experiments have been carried out using 

bubbling of a gas to keep wells free of ice.

The release of a compressed gas through a small hole in a pipe 

properly placed below the float near the bottom of a well creates 

vertical currents which bring the warmer water at the bottom of the 

well to the surface. This warmer water prevents freezing at the 

float. The water level in the well can then fluctuate to follow the 

water level in the stream and the float can operate the water-stage 

recorder. Power companies have used the method of bubbling air 

from an air compressor to prevent freezing of gates and equipment in 

the operation of hydroelectric plants. At most gaging stations, use 

of an air compressor is not feasible or necessary. A pressure cylinder 

of nitrogen can be used to supply the gas.

A standard cylinder of nitrogen (2,000 pounds per sqMare inch 

pressure when full) was used for the bubbler system (fig. 1). The 

outlet of the pressure regulator gage at the cylinder leads intc a i/^-inch 

air hose at the extremity of which is a short piece of ^-inch pipe that 

is reduced to a i/g-inch pipe capped at the end. A small hole was

50
ICE-PREVENTION SYSTEM FOR GAGE WELLS 51

FIGURE 1. Cylinder of nitrogen gas, regulator, and valve used 

to bubble gas into well to prevent ice from forming. Instrument on the right is a continuous float-operated waterstage recorder.

drilled with a size 50 drill near the end of the %-inch pipe. The setup 

is shown in figure 2. The %-inch pipe was oriented horizontally, with 

the hole under the center of the float at an elevation somewhat below 

the expected minimum winter stage; thus a stream of bubbles was 

directed toward the underside of the float.

This bubbling system operates satisfactorily if the depth of water 

in the well is not less than 4 feet. The rate of bubbling should be 

increased as the temperature decreases; for example, 50 bubbles per 

minute was sufficient early in the winter but a maximum of 100 bubbles 

per minute was needed during the coldest period.
52 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

W hose to 

nitrogen 

cylinder

Float

' W pipe

Water 

stage

--Gas 

bubble

elbow

=0

W pipe

FIGURE 2. Method of bubbling of gas in a gage well.

Some experiments have been made using compressed air (divers 

air) instead of nitrogen. This air is triple-filtered to remove as much 

moisture as possible, but the small amount of moisture that remains 

in the air has a tendency to freeze and clog the small hose and pipe, 

especially at temperatures of 0° and below. If this freezing occurs 

during an extended cold period, the float will freeze in the well and 

valuable record will be lost. Therefore, the use of nitrogen gas rather 

than compressed air is recommended.
ICE AUGER

By DALE PETTENGILL

ABSTRACT

The power-driven Swedish ice auger is an economical device for cutting holes 

through ice. When used with an electric drill and motor-generator set, the 

auger becomes an effective time-saving tool and reduces physical fatigue.

In regions of freezing temperatures, surface ice cover usually forms 

on streams each winter. Twenty to twenty-five holes must be cut 

through the ice on the streams when stream-discharge measurements 

are made. A simple and inexpensive device for cutting holes is the 

Swedish ice auger. A motor-generator set and an electric drill are 

needed for powered operation of the ice auger.

The cutting blade of the Swedish auger, a spadelike tool of hardened steel, is shown in figure 1. The auger is driven 'by a %-inch 

electric drill with power source from a 1,500-watt, 2-cycle, gasoline 

motor-generator set weighing 110 pounds. After some experimenting 

with the offset on the auger shaft, the model shown in figure 2 was 

found most suitable. In this model, the main shaft is 2% inches forward from the blade. This amount of offset effectively reduces the 

amount of vibration when using the auger. Cutting speed in solid ice 

is about 1 inch per second and the unit will satisfactorily cut through 

as much as 24 inches of ice.

The motor-generator set is mounted on a 4-foot toboggan to facilitate the handling of this equipment at off-road locations. The addition of the toboggan has made the equipment somewhat bulky, but 

has proved to be a time saver and has greatly reduced the physical 

exertion required to transport the equipment.

The total cost of the Swedish auger and shaft is about $7.00, $4.00 

for the auger blade and the remainder for the fabrication of the 

auger shaft.

Modern motor-generator sets that weigh only 50 pounds can be 

obtained now. When more compact and lighter motor-generator sets 

are developed, the equipment will become easier to transport. Then 

it may be possible to carry the whole kit in a packsack.

53
54 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

FiQiTBEl. Cutting blade of Swedish ice auger.

FIGURE 2. Ice-cutting equipment consisting of a motor-generator, mounted on 

a toboggan, electric-drill, and Swedish ice auger.
TIPPING HANGER FOR CURRENT METER AND SOUNDING WEIGHT USED FOR DISCHARGE MEASUREMENTS 

UNDER ICE COVER

By E. ROBERT HEDMAN

ABSTRACT

The development of power ice drills to cut holes for making stream-discharge 

measurements under ice cover created a need for measuring equipment that will 

go through a 5- to 7-inch hole in the ice. A new Geological Survey vertical-vane 

current meter, without the tail assembly used on conventional meters^ will pass 

through a 6-inch hole, but a sounding weight in a horizontal position on a regular hanger bar will not. A new tipping hanger lets the sounding weight tip 

into a vertical position so it can 'be lowered through a small hole, and then 

return to a horizontal position ready for taking soundings and velocity readings. 

To bring the equipment up through the hole in the ice the assembly is raised 

until a linkage on the back of the hanger touches the under surface of the ice 

cover and again tips the weight into a vertical position.

To make a discharge measurement when a stream is covered with 

ice, approximately 25 holes are chopped or drilled through the ice, 

and a current meter is lowered through each hole. The current meter 

is suspended on a wading rod if water depths are shallow and stream 

velocities are moderate. For greater depths and higher velocities 

the current meter must be suspended on a sounding cable with a sounding weight on a hanger bar below it. Chopping holes through ice 

cover on streams has long been a laborious and time-consuming job, 

but recent development of power ice drills has greatly reduced the 

time required to cut the holes. One of the most satisfactory ice drills 

presently manufactured will drill a 5- to 7-inch diameter hole, but 

the conventional cable-suspended discharge-measuring equipment will 

not pass through this size hole. Conventional equipment requires 

an elliptical-shaped hole about 6 inches wide and 2 feet long, because 

of the horizontal length of the sounding weight.

The U.S. Geological Survey has recently developed a short verticalvane current meter without tail fins. This vane-type meter is useful 

for discharge measurements under ice cover because it will pass 

through a small drilled hole (6-inch diameter) in the ice, and the vanes

55
56 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

FIGURE 1. Sounding weight tipped to a vertical position so it can be lowered 

through a small hole when making a discharge measurement through ice cover.
DISCHARGE MEASUREMENTS UNDER ICE COVER 57

FIGURE 2. Vertical-vane current meter with 30-pound Columbus-type sounding 

weight in horizontal position.
58 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

do not fill with slush ice. The tipping hanger described here was designed to use this vane-type meter suspended on a cable with a 30- 

pound Columbus-type sounding weight below it. With this hanger, 

the sounding weight can be tipped to a vertical position so the meterweight assembly can be lowered or raised through a 6-inch hole in the 

ice.

The hanger was cut from %-inch steel plate to a shape that fitted 

around the frame of the current meter, with space provided for easy 

removal of the meter contact chamber cap and pivot for servicing. 

The meter is clamped from the top and bottom to the hanger; it may 

be removed from the hanger by loosening the two clamps. The sounding weight is supported by two 1-inch-wide metal straps, one on each 

side, welded to the hanger plate and shaped into an inverted U. A %- 

inch diameter bolt through the lower end of the straps and the hanger 

pin hole in the sounding weight fastens the weight to the straps. The 

sounding weight can be pivoted about the hanger bolt, into a vertical 

position, with the nose of the sounding weight fitting into the U formed 

by the suspension straps. In that position, it can be lowered through 

a 6-inch drilled hole in the ice, and will return to a horizontal position 

for making velocity observations after clearing the bottom of the ice. 

When the assembly is raised, a hinged metal frame at the back of the 

hanger strikes the bottom surface of the ice and forces the tail of the 

sounding weight down to a vertical position which enables the assembly to be easily drawn back up through the hole.

In figure 1 the sounding weight is shown tipped into the vertical 

position so it can be lowered through a 6-inch hole. Figure 2 shows 

the sounding weight returned to its horizontal position so velocity observations can be made with the current meter. The sounding cable 

on which the current meter and sounding weight are suspended (figs. 

1 and 2) is 0.10-inch diameter reverse lay-cable that has a single insulated conductor inside; the cable is wound on a Geological Survey 

Type A-55 sounding reel, which accommodates 80 feet of this cable. 

The discharge-measuring equipment is-, mounted on a sled support 

built in the field office to fit local conditions.
FILTERING WATER SAMPLES USING VACUUM FROM 

AUTOMOBILE WINDSHIELD WIPER 1

By HUGH B. WILDER

ABSTRACT

Frequently it is desirable to filter water samples in the field at the time of 

collection. A very satisfactory method for doing this is to utilize tl » vacuum 

system that powers the windshield wipers on many automobiles to supply suction 

to conventional laboratory filtering apparatus.

To obtain chemical analyses that are representative of the natural 

character of a water it is usually necessary to separate the solvent 

water from any solid material carried in it by physical suspension. 

Changes in chemical and physical equilibra, which may occur rapidly 

once a water sample has been removed from its natural environment, 

often require that such separation be made in the field within a few 

minutes after a sample is collected. This seemingly simple task frequently presents difficulties because the suspended material is too 

finely divided to settle out naturally, and must be removed by filtration. The filtering medium necessary to filter out the suspended matter 

is usually of such low porosity that gravity alone will not provide 

sufficient force to pull the water sample through the filter quickly, and 

suction is needed to increase the rate of flow.

The vacuum system used to power the windshield wiper on many 

automobiles and trucks can provide a very effective suction for filtering 

water samples in the field. Most sampling sites are accessible by automobile, and a laboratory-type filtering apparatus can quickly be set 

up in the vehicle in the field. No special equipment is needed to adapt 

the wiper mechanism for this purpose: Simply disconnect one of the 

rubber tubes leading from the wiper motor under the dashboard, and 

replace it with a piece of laboratory pressure tubing long enough to 

reach a suction flask.

The apparatus used by the author consists of a 500 ml suction flask

1 An article by N. R. Harmon (p. 61) describes use of the vacuum supply di-ectly from 

the intake manifold of automobiles that do not have vacuum windshield wipers.

59
60 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

and a No. 1 Biichner funnel fitted with a No. 7 rubber stopper. (See 

fig. 1.) With this arrangement, coarse suspended matter can be removed with 5.5-cm conventional filter paper, and turbidity can be 

removed by use of 2-inch membrane-type filters. The membrane filters 

are somewhat smaller than the plate of the funnel, but by careful 

placement, the holes in the base can be adequately covered. The flask 

can be set on the floor of the car or, by use of clamps and aluminum 

rod, attached to some part of the interior of the vehicle.

Once the connections are made, it is only necessary to start the 

engine and turn on the windshield wipers to obtain suction through 

the funnel into the flask.

The suction flask must not be allowed to fill to capacity, or water 

will be sucked into the wiper system. To prevent this, a catch-bottle 

can be installed between the filter flask and wiper motor; however, 

this is an inconvenience that is not necessary if reasonable care is 

exercised in the filtering operation.

This apparatus has proved especially valuable while collecting water 

samples from test wells. Frequently, time and equipmert are not 

available to develop test holes sufficiently to obtain the perfectly clear 

samples necessary for a chemical analysis, and only by use of a good 

field filtering device is it possible to use the water sampler collected 

under those conditions.

.Vacuum-type windshield-wiper motor 

(under dashboard)

No. 1 Buchner funnel

500-ml suction flask 

FIQUBE 1. Apparatus for filtering suspended material from water samples, in the field, by using suction from a vacuum-type automobile 

windshield wiper.
FILTERING WATER SAMPLES USING VACUUM FROM 

AUTOMOBILE INTAKE MANIFOLD 1

By NEAI R. HABMON

ABSTRACT

Frequently it is desirable to filter water samples in the field right after they 

are collected. Vacuum to use with the filtering equipment can be obtained by 

tapping into the intake manifold of an automobile motor.

The vacuum system described by Wilder (p. 59) was successful, but 

many late-model automobiles are not equipped with vacuum windshield wipers. The author designed an apparatus to obtain vacuum 

directly from the intake manifold of the engine. Compared with hand 

vacuum pumps, this system, tested on certain station wagons and 

trucks having V-8 motors, has proved very effective and has resulted 

in a considerable saving of time and money. Samples can be filtered 

while field personnel are driving from one sampling station to another, 

and pump breakdowns have been eliminated. Hand pumps cost $26.00 

each the average cost of parts and installation for a manifold vacuum 

supply is $15.00. A hand pump is portable, but this vacuum-supply 

apparatus has been transferred easily from one car to another at a 

small labor cost.

The vacuum-supply apparatus consists of copper tubing, rubber 

tubing, a two-way brass stopcock, a flare nut, and a brass fitting. The 

copper tubing is attached by the brass fitting to a threaded plug hole, 

available on most intake manifolds. The rubber tubing, which should 

be about 4 inches long, is spliced into the copper tubing at the point 

of contact with the firewall to prevent motor-vibration noises. One 

end of a 4- to 6-inch piece of copper tubing is attached to the stopcock 

by a flare nut, and the other end is placed where the suction tubing of 

the filter kit can be easily attached and removed. (See fig. 1.)

The filter kit used with the vacuum-supply apparatus is the same as 

that previously used with the hand pump. It consists of a Millipore

»The author of this article modified the system developed by H. B. Wilder (p. 59) to 

use the vacuum directly from the Intake manifold of automobiles that do not have vacuum 

windshield wipers.

61

796-504 O 66 5
62 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

Rubber tubing 

Copper tubing >

Firewall

Motor of vehicle 

FIGTTBE 1. Apparatus to connect intake manifold of automobile to filter kit.

FIGURE 2. View of filtering kit connected to vacuum line. A, Stopcock on 

vacuum line that runs through dashboard of automobile to intake manifold of 

motor; B, rubber tube from filter slips over copper tubing of the vacuum line.

filter holder, a 500-ml Pyrex flask, about 2 feet of suction tubing, a 

box of Millipore filters type HA, and a base to hold the flask. (See 

fig. 2.)
INSTALLATION ASSEMBLY FOR CONDUCTANCE CELLS

By L. G. TOLEB and R. N. CHERRY

ABSTRACT

Electrodes for conductance recorders may require frequent removal from a 

stream for cleaning and replatinizing. An installation assembly that will 

facilitate removal of the electrodes and their return to a fixed position in the 

stream can be made from copper or plastic pipe, a brass rod, and two washers.

The monitoring of chemical changes in stream water is normally a 

part of any water-resources investigation. Records for at least 1 

year are required to define seasonal variations, and continuous records 

are preferred. One concentration parameter of water that can be 

measured continuously is electrical conductance. The electrical conductance is then related to the total mineral concentration and individual constituents in the water by periodic collection and analysis 

of water samples.

A continuous record of electrical conductance is obtained by installing a conductance cell in the stream in a fixed position. A conductor 

cable connects the cell to a recorder on a bridge or platform above the 

stream. At many of these conductivity-recorder stations the cell 

must be removed frequently to clean and replatinize the electrodes. 

To insure uniformity in the results, the conductance cell shoulc1 always 

be returned to the same level in the stream and oriented in the same 

direction. The installation assembly described here will facilitate 

the removal of the cell and the return to its original position.

The materials required are a 2i/£>-inch-diameter pipe (copper or 

plastic pipe is best in tidal streams), a brass rod, one washer with adjusting screws slotted on the periphery and one fixed wr,sher in 

the lower end of the housing pipe. A guide for the slotted washer 

must be anchored vertically against the inside of the housing pipe, 

above the fixed washer. The installation assembly is shown in figure 1.

63
64 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

Conductor cable

Brass rod for lifting 

cell from housing

Housing pipe, 2W 

copper or plastic

Tight-fitting 

hose clamp

Conductance 

cell

Vertical guide - enga?es 

slotted washer

Adjusting screw

Slotted washer, attached 

to electrode cove'

Electrode cover

Washer fixed to 

housing

Electrodes

FIGURE 1. Installation assembly for conductance cells. The 

housing pipe is fastened permanently to a bridge pier, or 

other structure. The electrode assembly can be lifted f~om 

or replaced in the housing pipe by using the brass rod as a 

handle. The slotted washer on the electrode cover engages 

the vertical guide on the pipe housing and insures that the 

electrodes are always returned with the same orientation.
INSTALLATION ASSEMBLY, CONDUCTANCE CELLS 65

The copper or plastic pipe houses the assembly and is installed so 

the top end is accessible on the mounting platform. Both washers 

are selected to fit over the cell cover and inside the housing pipe. The 

slotted washer is secured to the cell cover by means of adjusting: screws 

With the brass rod attached to the cell cover as shown, the cell may be 

rotated until the slot in the washer on the electrode cover assembly 

engages the vertical guide on the pipe housing. When the. slot in 

the washer engages the vertical guide, the electrodes are returned to 

the same directional orientation that they were in before th«y were 

removed. The fixed washer at the bottom of the housing pipe is a 

stop that positions the electrodes so they can always be returned to 

the same elevation.

In tidal streams, a copper screen may be attached to the bottom of 

the pipe to enclose the conductance cell and reduce the problem of 

barnacles and other sessile organisms.

Cost of the assembly for mounting a conductance cell is estimated 

as follows :

Material Cost

2 washers___________ $0.25

10 feet of copper tube___ 18. 00

10 feet of brass rod_____ 5.00

Material Cost 

Copper screen___ $2. 00 

Labor _____________ 25.00

Less expensive assemblies may be fabricated by substitution of other 

materials for copper.
USE OF THERMISTOR-THERMOMETER IN DETFRMINATION OF SPECIFIC CONDUCTANCE

By LEON S. HUGHES

ABSTRACT

Determination of the specific conductivity of water requires that tb<> resistance 

of a sample of the water in a conductivity cell and the temperature of the 

water in the conductivity cell be observed at precisely the same time. The 

thermistor-thermometer described here with the probe inserted d'rectly into 

the conductivity cell makes it possible to read the temperature at th<» same time 

that the resistance of the sample is observed. One step the need to refer to a 

graph or table to adjust data to the standard temperature of 25° C is eliminated 

by replacing the temperature scale on the thermistor-thermometer with one 

that reads directly in resistance of the standard calibration solution of 

0.00702# KC1 at the temperature of the water sample at the time of observation.

The specific conductance of water is a measure of the ability of 

the water to carry an electrical current. Chemically pure water has 

a very low electrical conductance but the presence of the dissociated 

ions increases the conductance of the solution. The specific conductance is therefore an indication of the total concentration of ionized 

substances in water, and the relation of dissolved solids to specific 

conductance can be defined for most waters (Hem, 1959, p. 37-43).

Specific conductance is easily and quickly determined and indicates the dissolved-solids content of water closely enough for many 

purposes. It is particularly valuable in showing the ehort-term 

changes that occur in the quality of streamflow. Conductance values 

are also used as a guide in selection of laboratory procedures for determining dissolved constituents and are an aid in checking the accuracy of analyses.

Specific conductance is determined by measuring the resistance of 

water by using a Wheatstone bridge in which a variable resistance is 

adjusted to equal the resistance of the unknown solution between 

platinized electrodes of a standardized conductivity cell. The conductance is the reciprocal of the resistance. As the temperature of a 

water solution of mineral matter rises, the conductance increases; 

therefore, to make conductance values comparable, they must all be 

referred to the same temperature. Conductivity data fcr natural 

water are referred to 25° Centigrade as a standard temperature. It 

is necessary either to have the water samples at 25° C or to determine 

the resistance at another temperature and compute specific conductance

66
THERMISTOR-THERMOMETER, SPECIFIC CONDUCTANCE 67

at 25° C. Instruments are available that provide automatic compensation for changes in temperature, and although these are excellent for fieldwork they are not sufficiently precise for laboratory 

use.

In Geological Survey laboratory practice each conductivity cell is 

calibrated by measuring, with the Wheatstone bridge, the resistance of 

a 0.007027\f potassium chloride (KC1) solution throughout the range 

of temperatures that can be expected in the water sample to be tested. 

Temperature of the 0.007027^ KC1 is observed to 0.1° C, and recorded 

at the same time the resistance of the KC1 solution is measured. A 

working graph of resistance of the 0.007027^ KC1 versus temperature 

is drawn.

Specific conductance of water samples to be tested has the same 

variation with temperature as the 0.007027V KC1 solution. Resistance 

values observed for water samples, at temperatures other than 25° 

C, are converted to specific conductance at 25° C by a simple arithmetic proportion relation with data from the working graph for 

0.007027V KC1 (Rainwater and Thatcher, 1960, p. 275). The relation is:

v - fi , . . . , . R of 0.007027V KC1 , nnn Specific conductance (micromhos) = 5 s ? X 1,000 ^ v ' R of sample '

where R=resistance in ohms.

R of the sample is measured with the Wheatstone bridge and R of 

0.007027V KC1 is taken from the working graph for the observed 

temperature of the sample at the time it is tested. The number 1,000 

is the known specific conductance of 0.007027V KC1 solution at 25° C.

One of the operational problems of measuring conductance of water 

samples is that it is difficult to obtain the sample temperature quickly 

and at exactly the same time that the resistance of the sample is 

measured. The temperature of the water sample is usually determined by inserting a thermometer directly into the sample bottle. 

Unless water samples are close to room temperature, the temperature 

of the sample may change in traveling to the conductivity cell, where 

resistance is measured, and be significantly different from that measured in the sample bottle. Some laboratories have the thermometer 

mounted in a bulb directly above the pipet conductivity cell. This 

latter arrangement assures that the temperature measured is the same 

as that of the water in the conductivity cell but may require the use 

of more of the sample than can be spared.

The apparatus described here uses a thermistor-thermometer available commercially, to measure the water temperature, at the same 

time the resistance is measured. A stainless-steel thermistor probe 

is inserted directly into the pipet conductivity cell. Figure 1 shows
68 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

Vacuum line,

FIGURE 1. Apparatus to measure conductivity of water. Note that thermistor 

probe is inserted directly into conductivity cell.

the complete conductivity apparatus. The original stopcock has been 

cut from the pipet cell, and a substitute stopcock has been connected 

by means of a glass tee and rubber-tubing joints. The thermistor 

probe, which is ys inch in diameter and 4y2 inches long, passes 

through the tee and into the top of the cell. If the probe is kept above 

the level of the electrodes, the cell constant is not affected.

The temperature is read from a scale covering a temperature range 

from 20° to 30° C, graduated in tenths of a degree. The instrument 

has been checked throughout its range and it agrees with precisiongrade thermometers to within 0.1° C.

Instead of the Fahrenheit scale, which originally occupied the 

upper part of the dial, a scale of resistance values for standard KC1 

has been substituted. This scale was prepared from the working
THERMISTOR-THERMOMETER, SPECIFIC CONDUCTANCE 69

graph, already discussed. The thermometer, therefore, indicates 

directly the KC1 resistance value for the sample temperature, and 

reference to a graph or table is not necessary.

The thermistor probe registers change in temperature very rapidly, 

indicating 99 percent of a full-scale change within about 4 seconds. 

Thus, by the time the cell is rinsed and refilled, the KC1 resistance 

value can be read off the dial.

Determination of specific conductance by using the the7*mistortherniometer requires 30-40 percent less time than by using an ordinary thermometer.

The cost of the single-channel thermistor-thermometer si own in 

figure 1 was $120 and the i^-inch diameter probe that is inserted in 

the conductivity cell, $25. Power supply for the thermistor-thermometer is a small 2.5-volt battery, reported to be good for 2,000 

hours of operation.

LITERATURE CITED

Hem, J. D., 1959, Study and interpretation of the chemical characteristics of 

natural water: U.S. Geol. Survey Water-Supply Paper 1473, 264 p.

Rainwater, F. H., and Thatcher, L. L., 1960, Methods for collection anc1 analysis 

of water samples: U.S. Geol. Survey Water-Supply Paper 1454, 3C1 p.
SPECTROPHOTOMETRIC DETERMINATION OF ALUMINUM USING ERIOCHROME CYANINE RC

By MARVIN J. FISHMAN

ABSTRACT

A spectrophotometric method for the determination of micrograri quantities 

of aluminum in water is described. Aluminum solutions buffered to a pH 

of 6.0 form, with Eriochrome Cyanine RC, a red lake which exhibits maximum 

absorbance at 535 m/j. Aluminum concentrations as low as 0.01 mg per liter can 

be. determined. Ascorbic acid inhibits the interference by iron. Interference 

by fluoride and silica are eliminated by evaporation of sample with concentrated 

sulfuric acid.

INTRODUCTION

Any one of several methods may be used to determine aluminum in 

water. Shull (1960) studied the aluminon method and modified it 

to improve its accuracy, sensitivity, and reproducibility. His modified method appears in "Standard Methods for the Examination of 

Water and Wastewater" (Am. Public Health Assoc. and others, 1960). 

Knight (1960) described a method using Solochrome Cyanine R as 

a color-forming reagent. Absorption is measured at 605 millimicrons. 

The method has a sensitivity of 0.004 milligrams per liter. Ascorbic 

acid eliminates iron interference; fluoride, orthophosphate in large 

amounts, pyrophosphate, and hexametaphosphate cause interference. 

In a review article on water analysis, Skougstad and Fishman (1961) 

described other colorimetric, fluorometric, and flame photometric 

methods for the determination of aluminum.

A sensitive method for determining aluminum in soil, ash, and 

plant materials is described by Jones and Thurman (1957). The 

results of a detailed investigation of Jones and Thurman's procedure 

using Eriochrome Cyanine RC and a recommended procedure for 

determining aluminum in water are presented in this paper.

GENERAL DISCUSSION

Principle. Dilute aluminum solutions buffered to a pH of 6.0 

form, with Eriochrome Cyanine RC, a red lake that exhibits maxi70
SPECTROPHOTOMETRIC DETERMINATION, ALUMINUM 71

mum absorbance at 535 m/x. Ascorbic acid inhibits the interference 

of iron. Aluminum concentrations of 0.01-0.5 mg per 1 can b? determined using 25 milliliters of the sample and higher concentrations 

can be determined by using less than 25 ml of the sample and diluting 

this to 25 ml.

Interferences. Fluoride concentrations of more than 0.4 mg per 

1 and silica concentrations of more than 80 mg per 1 cause low results. 

These interferences are eliminated by evaporation of sample with 

concentrated sulfuric acid. As much as 10 mg per 1 of orothophosphate does not interfere; as much as 2 mg of iron per 1 can be 

compensated for with ascorbic acid.

APPABATUS AND REAGENTS

Beckman Model B spectrophotometer (or equivalent) : 

Wavelength: 535 m/x. 

Cells: Fisher 23-ml absorption cell, cylindrical curvettes of

50-mm path length (Coleman) or similar. 

Phototube: Blue sensitive. 

Initial sensitivity setting: 2. 

Slit width: 23-ml cells, 0.06 mm (approximate), 50-mm cells,

0.12 mm (approximate). 

The following absorbances have been observed:

Al

(fig) Cell Absorbance

2.5______________ Fisher 23-ml ________________ 0.180

5.0______________. do___________________ .400

7.5______________ do___________________ .640

10.0______________ do___________________ .910

12.5_____________ do___________________ 1.160

2.5______________.Coleman 50-mm______________ .360

5.0______________ do___________________ .800

7.5______________ do___________________ 1.250

Glassware: All glassware should be rinsed first with 1:1 HC1 and 

then with metal-free water to avoid errors due to contamination.

Potassium alum, 1.00 ml=100 /*g Al+3 : Dissolve 1.758 g of A1K- 

(SO4 ) 2 ' 12H2O in metal-free water. Add 0.5 ml CHC13 and 

dilute to 1,000 ml with metal-free water.

Potassium alum, 1.00 ml=1.0 pg Al+3 : Dilute 10 ml of potassium alum 

solution (1.00 ml=100 /"g Al+3 ) to 1,000 ml with metal-free water.

Sulfuric acid, concentrated.

Eriochrome Cyanine EC, 0.075 percent: Dissolve 0.75 g of Eriochrome Cyanine EC in about 200 ml of metal-free water. Add 

25 g each of sodium chloride and ammonium nitrate; add 2 ml 

of concentrated nitric acid and dilute to 1,000 ml with metal-free
72 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

water. (The reagent is available from Allied Chemical Corp.

under the name of Alizarol Cyanine EC.) 

Ammonium acetate buffer, pH 6.0 : Dissolve 320 g of ammonium acetate in metal-free water ; add 5 ml of glacial acetic acid and dilute

to 1,000 ml with metal- free water. 

Ascorbic acid, 1 percent solution : Dissolve 1 g of L-ascorbic acid in

100 ml of metal-free water. This solution should to prepared

fresh each day.

PROCEDURE

1. Prepare a series of standards containing from 0.0 to 12,5 /x,g of Al 

in 50-ml volumetric flasks.

2. Pipet a volume of sample containing less than 12.5 /x,g of Al (25.0 

ml maximum) into a platinum dish.

3. Add 1 ml of concentrated sulfuric acid to samples and evaporate to 

dryness on a hotplate.

4. Transfer residues with metal-free water to 50-ml volumetric flasks.

5. Add 2 ml of 1 percent ascorbic acid solution.

6. Add 5 ml of 0.075 percent Eriochrome Cyanine EC solution.

7. Add 10 ml of ammonium acetate buffer solution and dilute to 50 

ml with metal-free water. Shake.

8. Read the absorbances of the sample and standards within 20 

minutes.

9. Determine the /x,g of Al in the unknown sample from a plot of absorbances of standards containing known amounts of aluminum.

CALCULATIONS

Determine the aluminum concentration by using the equation :

mg of £. Al * i per i 1= 

v-S ^ A.1 ;- 

& r ml sample

Keport aluminum concentrations below 1.0 mg per 1 to ty^o decimal 

places and greater than 1.0 mg per 1 to two significant figures.

RESULTS 

INTERFERENCES

Several samples of natural water were used to study the effect of 

interference and the accuracy and precision of the method. These 

samples represent a wide concentration range of dissolved materials. 

Known amounts of aluminum were added, and the samples were 

analyzed according to the described procedure except the evaporation 

step was omitted. The fact that aluminum recoveries wer?. lowest in
SPECTROPHOTOMETRIC DETERMINATION, ALUMINUM 73

those samples known to contain appreciable amounts of fluoride indicates serious interference from fluoride.

To determine the extent of fluoride interference, varying amounts 

of fluoride were added to solutions containing known amounts of 

aluminum. The results indicated no serious error when the fluoride 

concentration was less than 0.4 mg per 1; at concentrations of more 

than 0.4 mg of fluoride per 1 the interference from fluoride gradually 

increased, and aluminum recovery was low.

The extent of silica interference was determined by adding various 

amounts of silica of as much as 320 mg per 1 to solutions containing 

known amounts of aluminum. The results indicated that concentrations of silica of as much as 80 mg per 1 did not interfere; ir concentrations of silica more than 80 mg per 1 the interference from silica 

increased rapidly, and aluminum recovery was low.

Both fluoride and silica interferences can be eliminated by evaporating the samples to dryness with concentrated sulfuric acid. Fluoride 

is removed as volatile fluosilicic acid, and almost all the silica remains 

insoluble when the residue is redissolved.

The minimum volume of concentrated sulfuric acid rec-iiired to 

remove both fluoride and silica was determined. Results (table 1)

TABLE 1. Evaporation of samples with different volumes of concentrcf.ed H2SO4

prior to Al determination

[Result as In milligrams per liter]

Sample

!..._ - . .

2 . ___ ___

3.... ..... .................

Al added

0.00 

.06 

.20 ».38

.00 

.06 

.20 ».38

.00 

.06 

.20 

».38

No evaporation; 

no HjSO4

0.00 

.06 

.18 

.37

.00 

.00 

.09 

.23

.00 

.00 

.05 

.18

Al found

Evaporation; HjSOi as indicated 

6 drops

0.00 

.04 

.16 

.34

.00 

.04 

.17 

.30

1ml

0.00 

.06 

.20 

.38

.00 

.06 

.20 

.36

.01 

.05 

.20 

.36

2ml

0.00 

.07 

.20 

.37

.06 

.08 

.26 

.44

1 Correct for sample dilution.

showed that the addition of 1 ml of concentrated sulfuric acid will 

ensure virtually complete removal of fluoride upon evaporation of 

the sample. Results obtained on replicate determinations made on 

samples containing 1.2 mg of fluoride per 1 and varying known 

amounts of aluminum are given in table 2. The standard deviation
74 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

TABLE 2. Replicate aluminum determination on samples containing 1.2 mg

per I of fiuoride

[Results are in milligrams per liter]

Series

1. . ..- 

1.. ...............

3.... ... .... ......

4 - 

Al added

0.00

.05

.20

.40

Fisher 23-ml cells

Al found

10.02

.00

.00 

.00

.00

.00

.07

.07

.05 

.04

.06

.05

.18

.22

.22 

.20

.22

.22

.36

.38

.43

.43

.42

.40

Average

0.00

.06

.21

.40

Standard

deviation

(±)

0.00

$ .01

.02

.03

Coleman 50-nrn cells

Al found

10.02

.00

.01 

.00

.00

.00

.06

.06

.04 

.06

.04

.04

.18

.22

.22 

.20

.22

.22

Average

O.CO

.PS

.21

Standard

deviation

fcfc)

0.00

.01

.02

1 This value not included in results.

ranges from ± 0.00 mg of aluminum per 1 at the lowest concentration 

to ±0.03 mg of aluminum per 1 at the highest concentration. Known 

amounts of aluminum were added to samples of natural water containing 200 mg of silica per 1, and the samples were evaporated to 

dryness with 1 ml of concentrated sulfuric acid. Aluminum was 

determined in the solution of the residues. The recovery of aluminum was in excellent agreement with the amount of aluminum added 

(tableS).

TABLE 3. Evaporation of samples with sulfuric acid to eliminate

silica interference 

[SiOj concentration, 200 mg per 1]

Al concentration (mg per I) 

Sample Added 

0.00 

.05 

. 10 

.20 

.40 

.00 

.10 

.20 

.40

Found 

0.00 

.06 

.10 

. 18 

.38 

.00 

. 10 

.22 

.42
SPECTROPHOTOMETRIC DETERMINATION, ALUMINUM 75

Provision must be made to eliminate interference due to iron. Both 

thioglycollic acid and L-ascorbic acid have been used for this purpose. 

Jones and Thurman (1957) found that even with thioglycoUic acid 

iron interfered. However, a maximum level of interference was 

reached at 100 /*g iron. In their procedure they initially added 200 fig 

iron to both blank, standards and samples, and subtracted the aluminum found in the blank from the aluminum found in the standards 

and samples. From the recovery experiments they performed, the 

aluminum found agreed with the aluminum added. However, this 

procedure involves additional manipulations which can be eliminated 

by using ascorbic acid to complex the iron. The results obtained when 

ascorbic acid was used are included in table 4. Varying volumes of 1

TABLE 4. Elimination of iron interference using 1 percent ascorbic acid 

[Concentration in milligrams per liter ]

Fe concentration

0.00--- -- ---- __- 

.50. - - - - - 

1.0._ . -_- 

1.5-- - _ - 

2.0_ __-_----____----_---_____-__-___.___

4.0. _ _.___ _ _____ _____ 

Al i found in 

10 ml ascorbic 

acid

0 10 

1011 11

12 

0

5 ml ascorbic 

acid

0 10 

10 

10 

10 

10 

0

2 ml ascorbic 

acid

0. 10 

. 10 

. 10 

. 10

. 11 

. 11

i 0.10 mg per 1 aluminum was added initially.

percent ascorbic acid solution were added to solutions containing 

known amounts of aluminum and as much as 4 mg of iron per 1. Two 

ml of 1 percent ascorbic acid solution is sufficient to inhibit interference of as much as 2 mg of iron per 1. Four mg of ir:>n per 1 

results in a positive error of about 0.02 mg of aluminum per 1. Because of the close agreement between the amount of aluminum added 

to the samples and the amount recovered, it seems unnecessary, when 

using ascorbic acid, to add a known amount of iron as was done for 

thioglycollic acid.

Phosphate interferes in some aluminum procedures. Therefore, 

aluminum determinations were made on samples of water containing 

known amounts of aluminum and as much as 10 mg of orthophosphate 

per 1. Orthophospate did not interfere with these determinations. 

The effect of other phosphorus species was not studied.

COLOR DEVELOPMENT OF LAKE

The time required for the color of the aluminum-Eriochrome Cyanine RC complex to reach full intensity when ascorbic acid is added
76 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

is 1-2 minutes. The complex is stable for at least 14 minute? and only 

a very slight decrease in intensity is observed even after 20 minutes. 

The stability of the colored lake was not observed for a knger time 

because 20 minutes is sufficient to determine the absorbences of a set 

of several samples. Using thioglycollic acid, the time for full color 

development is 8 minutes; the color remains stable for an additional 

30 minutes.

PRECISION AND ACCURACY

For a 25 ml sample the standard deviation ranged from 0.00 mg per 

1 for an aluminium concentration of 0.00 mg per 1 to 0.0? mg per 1 

for an aluminum concentration of 0.40 mg per liter. Inasmuch as the 

errors were positive and negative with approximately equal frequency, 

it can be assumed that the accuracy of the determination is limited 

by the precision (that is, the inherent accuracy of the determination is 

better than the precision).

REFERENCES

American Public Health Association and others, 1960, Standard methods for the 

examination of water and wastewater: llth ed., New York, Am. Public 

Health Assoc., Inc., p. 48-51.

Jones, L. H, and Thurman, D. A., 1957, The determination of aluminum in soil, 

ash, and plant materials using Eriochrome Cyanine RA: Plant and Soil, 

v. 9, no. 2, p. 131-142.

Knight, A. G., 1960, Residual aluminum; its estimation and control: Soc. Water 

Treatment Exam. Proc., v. 9, pt. 1, p. 72-80.

Shull, K. E., 1960, Suggested modified aluminum method for aluminum determination : Am. Water Works Assoc. Jour., v. 52, p. 779-785.

Skougstad, M. W., and Fishman, M. J., 1961, Water analysis: Anal. Chemistry, 

v. 33, p. 138R.
SEMIMICROANALYTICAL METHOD FOR THE DETERMINATION OF IODIDE IN WATER

By C. G. MlTOHELL

ABSTRACT

The semimicroanalytical method presented for determining iodide in water 

is based on the catalytic effect of iodide on the ceric-arsenious oxidation reaction. 

In the presence of a small amount of iodide, the reaction follows first-order 

reaction-rate kinetics. At a given temperature aptid for a given reaction time, the 

extent of reduction of eerie ion is directly proportional to iodide concentration. 

The reaction may be stopped at any time by the addition of silver ion. Simple 

photometric measurement of the absorbance of the solution permits evaluation 

of the extent of the reactiofn. Most substances normally present in natural 

waters do not interfere.

INTBODUCTION

Iodide is in trace amounts in both rocks and water. Iodide concentrations in fresh waters range from 0.05 to 4.5 ppb (parts per billion) 

(Monier-Williams, 1950). Concentrations as high as 150 ppm (parts 

per million) have been reported in certain thermal waters.

An accurate determination of iodide in trace amounts is useful for 

the study of certain water problems. This paper presents an accurate 

method for determining trace amounts of iodide in water. T% e method 

may be used in research or routine laboratory analysis.

The method is based on the catalytic effect of iodide on the reduction of eerie ion by arsenious ion. After a given reaction time, the 

amount of unreduced eerie ions is measured photometrically. Three 

variables time, temperature, and amount of iodide present determine the rate and the extent of the reaction. Thus, for a pven temperature and reaction time, the extent of reduction of eerie ion is a 

function only of the amount of iodide present and is directly proportional to iodide concentration.

APPABATUS AND BEAGENTS

Test tubes, Pyrex, 20 by 150 mm.

Glass stirring rods.

Constant-temperature water bath (30° ±0.5° C).

796-504 O «6 6 77
78 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

Beckman Model B spectrophotometer (or equivalent) : 

Wavelength: 450 m/x. 

Cells: Fisher, 23 ml. 

Phototube: Blue sensitive. 

Blank: Distilled water. 

Initial sensitivity setting: 1. 

Slit width: 0.3 mm (approximate).

Arsenious acid, 0.3.A7 H3AsO3 (oxidation concentration) : Add 14.84 g 

of As2O3 to about 500 ml of demineralized water in a 1,000-ml 

beaker. Next, slowly add 28 ml of concentrated (96 percent 

H2SO4 (sp gr 1.84) and warm the mixture until the As2O3 is 

dissolved. Cool and transfer to a 1-liter volumetric flrsk, then 

dilute to 1 liter with demineralized water. Add a small piece of 

metallic arsenic to stabilize the solution (Kydd and others, 1950).

Ceric sulfate, O.LV Ce(HSO4 ),t (reduction concentration) : Prepare 

in a 1-liter volumetric flask by dissolving 52.84 g of anhydrous 

Ce(HSO4 ) 4 in 5N H2SO4 . Warm the mixture and stir occasionally 

until a clear solution is obtained (approximately 1 hour). Dilute 

to 1 liter with 5A7 H2SO4 and store away from light. The normality of this solution should be checked against the 0.3.A7 H3AsO3 

to assure that 3 volumes of O.LV Ce(HSO4 ) 4 react, in the presence 

of I-1 , with 1 volume of 0.3# H3AsO3 .

Silver nitrate, 0.01 percent AgNO3 by weight: Store in a dark bottle.

Sulfuric acid, 5N H2SO4 : Slowly add 138.8 ml of concentrated (96 percent) H2SO4 (sp gr 1.84) to about 500 ml of demineralizei water; 

mix and dilute to 1 liter.

Potassium iodide (stock solution), 1.00 ml=0.10 mg I'1 : Dissolve 0.131 

g KI, dried overnight in a sulfuric acid desiccator, in demineralized water, and dilute to exactly 1 liter.

Potassium iodide (standard solution), 1.00 ml=0.0001 mg I"1 : Dilute 

1.0 ml of stock KI solution to 1 liter with demineralized water.

ANALYTICAL PROCEDURE

Pipet blank and standards containing 0.00-1.2 /*g I'1 , and samples 

containing less than 1.2 ju,g I'1 (20.0 ml max) into Pyrex test tubes 

(20X150 mm). Dilute each sample and standard to 20.0 ml. Add 

1.0 ml of 0.37V H3AsO3 to each tube; stir. Place all tubes and the 

bottle containing Ce(HSO4 ) 4 in a constant-temperature bath at 30° C. 

Allow time (30-45 minutes) for samples and Ce(HSO4 ) 4 to reach 

temperature equilibrium. At zero time add 1.0 ml of O.LV Ce(HSO4 ) 4 

to standards and sample, and mix thoroughly. After exactly 10 minutes add, while stirring, 1 drop (0.05 ml) of 0.01 percent AgNO3 .
SEMIMICROAKALYTICAL DETERMINATION, IODIDE 79

Measure absorbance at 450m/i. The instrument is set to 0.000 absorbance with distilled water. The ratio of As (absorbance of standard) to 

Ab (absorbance of blank) is obtained and the iodide content of the 

sample is calculated from a calibration curve (fig. 1).

o.oi

0.0 0.2 0.4 0.6 0.8 i.o 1.2 1.4

FIGURE 1. Calibration curve (mean of six determinations) used in determination

of iodide in water.
80 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

CALCULATIONS

1. Construct a calibration curve (fig. 1) by plotting the ratio As: Ab 

against jug of I'1 on semilog paper.

2. From the curve, determine jug I'1 corresponding to the absorbance 

ratio obtained for the sample.

3. ppm I"1 =i rr X i f-XMg I"1 

rtr density ml sample &

Report I-1 concentrations of less than 0.1 ppm to three decimal places 

and those greater than 0.1 ppm to two significant figures.

DISCUSSION

In the presence of iodide, the reaction follows first-order reactionrate kinetics (Glasstone, 1940, p. 1118; Kontaxis and Pickerir g, 1958). 

Figure 2 shows that, at a temperature of 30° C, the optimum reaction 

time for determining 0.0-1.2 ju.g of iodide is 10-12 minutes. A reaction 

time of 10 minutes was selected for this procedure for convenience.

The inhibitory effect of silver ion on the reaction has been previously 

observed (Kontaxis and Pickering, 1958). Other ions such as mercuric or hypochlorite (Rossum and Villarruz, 1960) also may be used 

to arrest the reaction. The effectiveness of silver ion is shown in table 

1. After the addition of silver nitrate there is no change in absorbTABLE 1. Change in absorbance after addition of silver nitrat"

Time, In hours, after addition of AgNOa

Mgl-'

O.O. 

.2

.4.. ... ... ... ... ...

.6 _ 

1.0 

1.2. 

0 1 0.5 1.0 2.0 3.0 4.C 5.0

Absorbance

0.860 

.506 

.306 

.158 

.094 

.044 

.022

0.860 

.505 

.307 

.158 

.093 

.045 

.022

0.795 

.484 

.292 

.154 

.089 

.043 

.022

0.664 

.440 

.261 

.145 

.078 

.039 

.022

0.585 

.410 

.252 

.140 

.080 

.036 

.022

0.470 

.370 

.230 

.128 

.073 

.031 

.017

0.391 

.330 

.290 

.116 

.067 

.032 

.016

ance for a period of about 30 minutes; after 30 minutes the color 

gradually fades and the absorbance decreases.

The advantages of arresting the reaction by adding silver ion are:

1. The determination of the absorbance of the samples after an exact 

reaction period is possible.

2. Rigid control of temperature during spectrophotometric measurement is unnecessary.

3. The manipulation of individual samples is simplified an'! several 

samples may be analyzed conveniently at one time.
SEMIMICROANALYTICAL DETERMINATION, IODIDE 81

0.01

0 5 10

REACTION TIME, IN MINUTES

FIGURE 2. Time relation of the ceric-arsenious reaction. 

RECOVERY TEST

The iodide concentration of each of 10 natural-water samples was 

determined by the procedure described. The concentrations ranged 

from 2 to 18 ppb. Different known amounts of standard ioiide solution were then added to 10-ml aliquots of each sample, and the total 

amount of iodide was determined. Results of this test (tabl°t 2) show
82 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

TABLE 2. Recovery of added iodide 

[Results in micrograms]

Sample

1

2__ _

3

4

5 -------------

6 __

7 -------

8 -------------

9

10----------------

lodide in 

10-ml sample

0 08 

03 

04 

04 

02 

03 

10 

18 

14 

12

Iodide 

added

0 50 

10 

20 

50 

60 

60 

50 

30 

20 

10

Total 

iodide

0 58 

13 

24 

54 

62 

63 

60 

48 

34 

22

Iodide 

recovered

0 53

16 

29 

50 

64 

64 

60 

48 

35 

21

Error

0 05 

03 

05 

04 

02 

01 

00 

00 

01 

01

Mean error._-__---__________---______-_____-____-_____ 0.02 jug I"1

Maximum error._______________________________________ .05 jug I"1

a maximum error of 0.05 jug of I"1 per 10-ml sample (0.005 ppm) and 

a mean error of 0.02 yu.g of I'1 (0.002 ppm).

INTERFERENCES

Low values for I"1 may result if the reaction test tubes are not 

thoroughly clean. Each sample tube should be thoroughly rinsed with 

HC1 to remove possible contaminants.

Bromide does not interfere; any oxidizing agent that oxidizes iodide 

to iodine has no effect on the reaction. However, certain phosphate 

compounds used in water treatment (Calgon, for example) inhibit 

the reaction. This effect can be eliminated by adding three drops of 

concentrated nitric acid to the sample when placed in the test tube. 

The nitric acid should be aerated to remove nitrogen oxides. The 

effects of this treatment are shown in table 3.

TABLE 3. Interference of Calgon on iodide determination

Absorbance

MS I'1

0 0 _ -_--_---_-_-_----_-----_----

2__ _- - 

4_-_-_- __ _ ___---_--

6_ _-. --_-.--_-_-__-_------.-_-

8_-.----------_- ----------------

1 0. -------- ------------------

1 2___-------._. -_-------_-__----

Standard only

0 860

506

306

158

094

044

022

Standard containing 2 ppm 

Calgon

0 860

850

844

836

821

765

740

Standard contfining 2 ppm 

Calgon and 

3 drops HNOs

0. 860

. 511

.308

. 160

.095

.044

.023
SEMIMICROANALYTICAL DETERMINATION, IODIDE 83 

REFERENCES CITED

Glasstone, Samuel, 1940, Textbook of physical chemistry: New York, Van 

Nostrand Co. 1289 p.

Kontaxis, N. E., and Pickering, D. E., 1958, A micro-method for the determination of butyl-alcohol extractable hormonal iodine in serum: Jour. Clin. 

Endocrinol. and Metabolism, v. 18, p. 774-786.

Kydd, D. M., Man, E. B., and Peters, J. P., 1950, Concentration of precipitable 

iodine (SPI) in the serum : Jour. Clin. Inv., v. 29, p. 1033-1040.

Monier-Williams, G. W., 1950, Trace elements in food: New York, Join Wiley & 

Sons, Inc.

Rossum, J. R. and Villarruz, P. A., 1960, Suggested method for iodide determination : Am. Water Works Assoc. Jour., v. 52, no. 7, p. 919-922.
SYSTEM FOR MONITORING FLUVIAL SEDIMENT

By H. P. GUY

ABSTRACT

The determination of fluvial-sediment concentration and discharge is expensive 

and hence limited in proportion to needs. A complete monitoring system based 

on (a) a continuous recording for fine sediment, (b) the use of existing gageheight records and theoretical considerations for coarse sediment, and (c) a 

central computing center is suggested to lower costs and improve the published 

statistics. With existing sampling equipment periodic measurements would be 

required to adjust the fine-sediment recording and shift the rating for coarse sediment similar to rating adjustments presently applied to computations for 

water discharge. They new system would make available many more kinds of 

statistics on a more timely basis than can be obtained by present techniques.

INTRODUCTION

The processes of erosion and deposition on. the landscape cause a 

highly variable quantity of sediment to be moved by streams. This 

sediment in transport poses many kinds of problems in the use of such 

streams. If the problems posed by sedimentation and their amelioration are to be considered in a realistic framework, it is essential that 

the amount of sediment in streamflow be well defined in time and 

space.

Methods presently used to obtain knowledge of fluvial sediments 

require personnel and equipment to:

1. Obtain one or more depth-integrated samples of the streamflow for 

each observation in time and space ([U.S.] Federal Inter-Agency 

Committee on Water Resource, 1963, p. 19-60).

2. Transport the samples to the laboratory.

3. Analyze the samples for concentration of sediment.

4. Interpret the sample data in the light of streamflow and other environmental data to arrive at a time distribution of sediment 

concentration and discharge.

5. Interpret the time distribution of sediment concentration and sediment discharge for means, variance, frequency distributors, trends, 

and correlation with respect to other physical data.

84
MONITORINO PLUVIAL SEDIMENT 85

This chain of techniques is relatively cumbersome, time consunc ing, and 

expensive, and has caused the knowledge of stream sediment to lag 

seriously other related fields of hydrology.

Kecent developments ([U.S.]Federal Inter-Agency Committee on 

Water Kesources, 1963, p. 118-135) indicate that more efficient and 

effective methods may be used to obtain the necessary krowledge 

of fluvial sediment. These new methods should logically evo] ve from 

considering sediment in streamflow in the light of fine sediment 

(<0.062 mm) and coarse sediment (>0.062 mm); therefore, in the 

discussion to follow, it is convenient to consider separately the transport of fine sediment and of coarse sediment.

FINE SEDIMENT

Fine sediment is easily suspended by natural stream turbulence, 

and hence travels through a stream system with about the same 

velocity as the water. The quantity and rate of fine-sediment transport at a stream cross section are the result of erosion in the t asin and 

the routing of the particles with the flow to the cross section in question and are consequently independent of the stream in a particular 

reach. The concentration of fine sediment in transport during stormflow is unpredictable with respect to time and frequently increases 

by a factor of 100 or 1,000 times that of "normal flow." Thus, much 

of the error in sediment data obtained by present measurement techniques results from a lack of sufficient observations to define this 

large variation in concentration.

A logical step to improve the sediment record is to develop a recording device to sense the fine sediment continuously, or at least every 

few minutes. Such a recording device may be developed on the basis 

of attenuation and scattering of light, nuclear radiation, or sound 

by the fine sediment. Because the fine sediment is rather uniformly 

distributed in the stream cross section, a representative sample can 

be pumped from nearly any point in the section to the sensing device. 

Inasmuch as the kind of fine sediment will vary somewhat from basin 

to basin and within a given basin, such a device must be calibrated 

for each stream and periodically with the seasons by mean« of conventional samples. Even if such a calibration has some error the 

continuous recording will result in a greatly improved record of finesediment discharge over that presently obtained with daily or even 

hourly depth integrated samples.

COARSE SEDIMENT

The coarse sediment, usually found in appreciable quantities on the 

bed of the stream, is transported at a rate that depends on the prop-
86 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

erties of the fluid, the flow, the channel geometry, and the sediment. 

Because the slope, width, and sediment character of moet natural 

streams are relatively stable, the main variables affecting the transport 

of coarse sediment are the water discharge and the bed resistance. 

Colby (1961) has related the discharge of bed material (ccarse sediment) to depth and velocity of flow; thus, it logically follows that 

water discharge can be related to coarse-sediment discharge. The 

water discharge is computed on the basis of stage, which is continuously recorded at gaging stations. The pen-type stage recorders 

are rapidly being converted to digital paper-tape recorders (Carter 

and others, 1963). For streams where such digital recorders are in 

use, the digital computer can be used to compute the coarse-sediment 

discharge on the basis of the streamflow records.

Colby (1964) also suggested refinements of the relation of coarsesediment discharge to depth by consideration of the water temperature 

and fine-sediment concentration. Values of both of these variables 

would be obtained by the basic stream-measurement system and then 

fed into the computation for total sediment transport. Again, as 

with fine sediment, conventional samples will be required to "calibrate" 

or modify Colby's relation to compensate for irregularities or permanent changes of stream cross section and for approach conditions 

which affect the stream velocity and the character of the seiiment in 

transport.

For many streams, velocity and depth will conform to a reasonably stable rating with gage height, and a stable relation of coarsesediment discharge to stage will permit a continuous recori of sediment discharge. Such an indirect method of obtaining a continuous 

quantitative record of coarse sediment in streamflow probably would 

be superior to a record computed entirely from single-vertical samples, 

especially if the results of periodic measurements of the ccarse sediments moving in the entire stream cross section were used to adjust 

the computational ratings. The adjustment of coarse-sediment transport with time would be similar to adjustments presently applied 

to single-vertical sampling techniques and to water-discharge ratings. 

The periodic conventional sediment-discharge measurements also can 

be used to define the size gradation of the material in transport.

THE SYSTEM

The heart of the automation technique for obtaining more and 

better knowledge of sediment in streamflow would be a digital computer such as the one in use by the U.S. Geological Survey for obtaining water discharge data. A schematic diagram (fig. 1) illustrates 

the assembladge of the components required for the complete system,
MONITORING FLUVIAL SEDIMENT 87

Computations by digital computer 

for time distributions

y V Y

Fine Coarse Total

Y Y Y

Computations by digital computer for means, 

variance, frequency distributions, trends, and 

correlations with other physical and hydrologic data

Periodic stream 

measurements with 

current meter and 

depth integreting 

sampler

Office and laboratory 

analysis of sarr pies 

and measurements

FIGURE 1. Schematic diagram of a system for monitoring fluvial sediment.

from the recording and manual measurements at the stream to the 

data required for input to the computer and the final publication. 

Present techniques seldom go farther than publication of the time 

distributions (daily means) of sediment concentration and sediment 

discharge. In addition to much more timely publication of data, an 

added justification for the automation techniques is that the sediment 

data can be assembled into more complete and meaningful statistics 

than can be derived from data obtained by the present techniques. 

A system for monitoring fluvial sediment cannot be completely 

implemented quickly or easily. Operational research and teeing of
88 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

several stages will require time and services of experts in m any fields 

of endeavor. For example, several man-years of efforts are being expended by the project of the Federal Inter-Agency Committee on 

Water Resources on turbidimeter equipment and its accessories. Advances in technology will provide opportunities for simplified and 

more effective methods for many components in the system. Several 

methods are available for transmitting detected data from the stream 

to processing or computing and printing machines. For optimum 

benefit all components within the system must be carefully integrated 

with other monitoring systems for stream and environmental data 

such as water discharge, conductivity, dissolved oxygen, pH, water 

temperature, air temperature, precipitation, and sunlight intensity.

REFERENCES

Carter, R. W., Andersen, W. L., Isherwood, W. L., Rolfe, K. W., Showen, C. R., 

and Smith, Winchell, 1963, Automation of streamflow records: U.S. Geol. 

Survey Circ. 474,18 p.

Oolby, B. R., 1961, Effect of depth of flow on discharge of bed material: U.S. 

Geol. Survey Water-Supply Paper 1498-D, 12 p.

 1964, Practical computations of bed-material discharges: Am, Soc. Civil 

Engineers Proc., v. 90, No. HY2, p. 217-246.

[U.S.] Federal Inter-Agency Committee on Water Resources, 1963, Determination of fluvial sediment discharge, in A study of methods used in measurement and analysis of sediment loads in streams: Rept. 14,151 p
SINGLE-BOTTLE SAMPLING IN OPERATION OF A 

SEDIMENT STATION

By J. R. GEORGE and J. W. WARK

ABSTRACT

An analysis of sediment-sample data for the Delaware River at Trenton, N.J., 

indicates that single-bottle sampling provides results that compare favorably 

with suspended-sediment concentrations determined from multiple-bottle samples. 

Where sediment concentration of a stream changes slowly with respect to time 

and concentration generally is well distributed with respect to stream depth, these 

data suggest that adequate definition of suspended-sediment concentration can 

be obtained with single-bottle samples.

Samples of the suspended-sediment concentration of a flowing 

stream are intended to represent conditions in the stream. Where 

sampling conditions are generally good and the supporting streamflow 

data are readily available, a properly operated sediment-sampling 

station should fulfill most of the specific needs for suspended-sediment 

data.

Fixed sediment-sampling installations similar to that shown in 

figure 1 are designed for ease of sample collection. Residents of the 

area are hired to visit the stream site frequently during periods of 

changing streamflow or stream-sediment conditions to collect several 

1-pint bottle samples. The water samples are analyzed in the laboratory to determine the load of suspended matter that they contain. This 

information may be used by the engineer or scientist in a wide variety 

of studies.

This study is for a sediment station where water samples are taken 

in only one vertical in the cross section at the sediment-measuring station. A water sample is taken with the U.S. D-43 sampler by making 

a vertical traverse from the water surface to the stream bottom and 

back up to the water surface. The U.S. D-43 sampler contains a pint 

milk bottle. The sampler is moved at a constant vertical speed (down, 

then up) while making the vertical traverse, at a speed selected so 

the pint bottle is approximately filled when the traverse is completed. 

This is a depth-integrated sample. Customary water-sampling practice is to obtain one bottle of water by making the surface-to-bottom

89
90 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

FIGURE 1. Typical sediment sampling installation with U.S. 

D-43 suspended-sediment sampler. Sampler nose (A) 

pivots upward at hinge (B) so pint milk bottle can be inserted or removed from sampler; C, intake nozzle.

and back-to-surface traverse and then to obtain a second bottle by immediately repeating the same procedure. This is then a two-bottle 

sample.

Multiple-bottle sampling, the collection of two or more samples almost simultaneously, has been a normal part of sediment-station operation for some time. Several bottles collected in this manner presumably should provide a better figure of average concentration than 

would a single-bottle sample. However, a critical comparison of 

single and multiple-bottle sampling may uncover only minor differences in results. These differences in results may be neither justified 

by the use that will be made of the data nor worth the extra cost of 

the multibottle sampling. Where little variation exists, a one-bottle
SINGLE-BOTTLE SEDIMENT SAMPLING 91

sample may provide adequate definition of the suspended-sediment 

concentration. If so, processing single-, rather than multiple-, bottle 

samples will produce a significant saving of time in bottle handling 

and laboratory analysis. This article presents a comparison of the 

sediment-concentrations loads obtained from one-bottle samples with 

those obtained from two-bottle samples, all collected on the Delaware 

River at Trenton, N. J.

The prerequisites for successful single-bottle sampling are: (1) an 

adequate depth-integrating sample technique as described by the [U.S.] 

Federal Inter-Agency Committee on Water Resources, Subcommittee 

on Sedimentation (1963), (2) generally stable distribution of suspended sediment, with respect to stream depth, and (3) a relatively 

slow change in water discharge and sediment concentration with 

respect to time. Each of these conditions appears to exist at the U.S. 

Geological Survey sediment-measuring station on the Delaware River 

at Trenton, N.J.

Sediment-concentration data for Delaware River at Trenton, N.J., 

from 1954 to 1957 were used in this analysis. The average concentration from a two-bottle sample was compared with the concentration 

from the first bottle of the sample set. Concentration values were 

grouped into 15 classes ranging from 1 to more than 1,000 ppm (parts 

per million). As many as 40 observations were selected for study in 

each concentration class and a comparison of the results appears in 

table 1. The mean deviation of single-bottle concentrations from the 

average for concentration classes of 30 ppm and greater was only ±6 

percent. Greater deviations that appear in the low-concentration

TABLE 1. Deviation of single-bottle sample concentration from two-bottle average, 

Delaware River at Trenton, N.J.

Concentration class (ppm)

1- 4__ _____________________

5- 9___------__-_-__-_____-

10- 19_____-.________________

20- 29 ___ __________________

30- 39 --- _________________

40- 49 ____ __ _ _ _ ___

50- 69____-__-_---_____--__-_

70- 99 _-_ _____ __ 

100-199_ __ _._ ___ __ ____ _

200-299 _ __ ___ 

300-399-___--_-___---__----_-_

400-499-____-_---_-_____-_--_-

500-699. _____________________

700-999 __ _ __ 

=~ 1,000 __ ____ __ __________

Number of 

samples

40

40

40

40

40

26

40

38

40

31

16

25

14

13

19

Mean deviation (±) 

from two-bottle average 

(percent)

35 (1 ppm)

23 (1-2 ppm)

13 (1-2 ppm)

13 (2-4 ppm)

5.0

5.5

4.8

5.3

5.2

5.5

6.7

4. 5

6.7

4.2

6.3

Percent of time 

daily concentration is less than 

class (1950-57)

30

59

79

85

88

90

93

95

98

99.0

99.5

99. 7

99. 8

99.9
92 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

classes (1-29 ppm) should be attributed largely to rounding procedure 

and weighting error. To present another perspective to these higher 

deviations, they also are expressed as concentration, in parts per million, in table 1. Although the concentration frequency shown in table 

1 indicates that the sediment concentration of Delaware River is less 

than 30 ppm about 85 percent of the time, errors introduced randomly 

by reliance on single-bottle sample data are small in terms of actual 

suspended-sediment concentration. It is noteworthy that measured 

sediment loads produced at this concentration range usually constitute 

less than 10 percent of the annual sediment load.

Because average values may be misleading, a histogram of these 

data appears as figure 2. This figure suggests that the deviation of 

the one-bottle concentration from the two-bottle average is randomly 

distributed about zero (0) with an expected error of less than 10 percent for about two-thirds of the samples collected.

120

100

-30 -10 0 +10 +30 +50 

DEVIATION FROM TWO-BOTTLE CONCENTRATION, IN PERCENT

>+58

FIGURE 2. Deviation of one-bottle sediment concentration from two-bottle 

concentration, Delaware River at Trenton, N. J.
SINGLE-BOTTLE SEDIMENT SAMPLING 93

In summary, this discussion suggests that single-bottle samples of 

the Delaware River at Trenton, N.J., yield reliable concentration results for defining stream-sediment characteristics. At other sampling 

stations, where the requisite conditions mentioned previously exist, 

one-bottle sampling can be expected to give results that compare 

equally well with multibottle sampling.

REFERENCE

[U.S.] Federal Inter-Agency Committee on Water Resources, Subcommittee on 

Sedimentation, 1963, Determination of fluvial sediment discharge: Minneapolis, Minn., St. Anthony Falls Hydrol. Lab., Kept 14, 151 p.
RIVER-BOTTOM SEDIMENT SAMPLING WITH A 

SWEDISH FOIL, SAMPLER

By R. J. PICKEEING

ABSTRACT

The collecting of undisturbed core samples of fine, somewhat fluid sediment 

is hampered by the tendency of the sediment to adhere to the interior of the 

sampling tube and thus cause compaction and preferential coring of certain 

sediment layers. In the Swedish Foil Sampler, this tendency is minimized by 

the insertion of a sheath of metal "foils" between the sediment core and the 

sample tube. The foils hold the sediment sample in place and let the sample tube 

move downward without carrying the sediment sample along with it and without 

compacting the sediment

During the past 20 years the Oak Ridge National Laboratory has 

released very small but measurable amounts of radionuclides into the 

Clinch River in eastern Tennessee, and thereby created a unique opportunity for determining the distribution and behavior of fission products in a natural stream. A joint study of the fate of radionuclides 

released to the Clinch River has been carried on by the Water Resources Division of the U.S. Geological Survey and the Oak Ridge 

National Laboratory since February 1960 as part of the general program of the Clinch River Study Steering Committee. Undisturbed 

core samples of river-bottom sediments were required for phases of 

the joint study pertaining to the vertical distribution of fission products in the sediments.

Preliminary coring tests with several tools showed that the simple 

tube-type samplers were unsatisfactory for use in the relatively fine 

bottom sediment of the Clinch River. Particle-size distribution in 

the sediment is fairly constant throughout the part of the Clinch 

River that contains radioactive sediment; the sediment is composed 

of approximately 15-20 percent clay, 25-30 percent sand, and 50-60 

percent silt. With tube-type samplers there was preferential coring 

of certain sediment layers and excessive compaction of the sediments 

in the core sample. Driving thin-walled tubes having inside diameters 

of 3-4 inches into the river sediments caused much less compaction of 

sediments than did driving tubes having diameters of 1-2 inches 

(P. H. Carrigan, oral commun., 1962), but still better control of compaction was necessary. 

94
SEDIMENT SAMPLING, SWEDISH FOIL SAMPLER 95

.Sample, tube/:;":/;"::.. 

'Foil magazine

ifC'iitting-shoe:'-: .;: ' 

^assembly i-i-.V-i-:

FIGURE 1. Equipment for obtaining core samples of sediment from a riverbottom. A, Float with hoisting engine and rigging for driving and raising the 

sampler. B, Swedish Foil Sampler; pieton is held in place by chain as sample 

tube is pushed down through the sediment; end of each foil strip is attached 

to piston and the strips of foil unroll from the magazine and envelope the sediment core as sampler is pushed into the sediment; the core is not compacted 

because the foil enveloping it does not move.
96 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

Further tests and inquiry resulted in the selection of the Swedish 

Foil Sampler for sampling bottom sediments in the Clinch River. The 

Foil Sampler, a patented device operated under exclusive license in 

the eastern United States, is a piston-type sampler in which thin axial 

metal strips (foils) are used to eliminate friction between the sediment core and the sample tube while coring is proceeding. Cores 2y2 

inches in diameter and as much as 14 feet in length were obtained in 

water as much as 45 feet deep with the Foil Sampler mounted on a 

barrel float equipped with a drilling tower and gasoline engine and 

hoist. (See fig. 1.) More than 100 undisturbed cores were collected 

at 14 cross sections on the Clinch River and at 4 cross sections on 

2 tributary streams.

In loading the sampler, steel foils, fed from coils in the foil magazine, are attached to the piston assembly. As the piston assembly is 

pushed up into the sample -tube a short distance, the foils are pulled 

down around the lip of the tube and up along its interior surface (figs. 

1 and 2-4). After the magazine shield, cutting-shoe housing, and 

cutting-shoe assembly (fig. 2Z?) have been attached, the Foil Sampler 

is ready for lowering.

The distance from the water surface to the sediment surface must 

be measured accurately with a weighted line before coring can proceed. The sampler is then lowered to within a few inches of the sediment surface, and the piston chain is fixed to a hook at the top of the 

drilling tower (fig. 1). As the sampler is pushed into the sediment, 

the foils unroll and form a sheath that encloses the core and prevents 

its contact with the interior of the sample tube. The core does not 

move relative to the foil strips, and the only friction in the sample 

tube is the metal-to-metal friction between the foils and the interior 

of the tube. Compaction and blocking of the core in the tube due to 

friction between the sediment and the tube is thus prevented. During 

the insertion of the sample tube into the sediment, the piston and the 

core of sediment do not move from their original positions.

The primary function of the piston in a piston sampler is to prevent loss of core while the sampler is being raised to the surface. 

Because of the rigid sample tube and the tight-fitting piston immediately above the core, the hydrostatic force due to the column of water 

above the base of the sample tube can act on the core only in an 

upward direction; thus the core is held in the tube. If the core begins 

to slide out of the tube, a partial vacuum is created between the top 

of the core and the piston, which is locked in position while the sample 

tube is being raised; this vacuum increases the differential upward 

push of hydrostatic pressure on the core and inhibits its further movement. Adhesion of the core to the metal foils of the Swedish Foil 

Sampler also tends to hold the core in the tube.
SEDIMENT SAMPLING, SWEDISH FOIL SAMPLER 

Sample tube

97

Foil magazine

Magazine 

shield

Cutting shoe 

housing

B

FIGURE 2. Swedish Foil Sampler. A, Magazine in head of sampler showing 

coils of steel foil; ends of foil are attached to piston which has been pushed 

up and is now inside of sampler head; foil strips unwind from rolls in the 

magazine as the sampler travels down and the piston remains in place held 

by a chain anchored to the drilling tower. B, Top to bottom, sampler head, 

magazine shield, cutting-shoe housing, and cutting-shoe assembly. C, Cuttingshoe assembly pulled apart to show basket-type core retainer used to retain 

cores that have a high tendency to slump. Photographs by Oak Ridge National 

Laboratory.

Under certain sampling conditions, satisfactory cores could not be 

obtained with the sampler. Recovery of river sediment was excellent 

at points near the bank where the river sediment overlies soil, but in 

the deeper parts of the river channel where soft sediment lies directly 

on bedrock, the lower 6-18 inches of the sample was commonly lost. 

To decrease core loss, a modification to the cutting-shoe assembly was 

made. A basket-type core retainer was designed for the sampler, and 

upon request, was fabricated by the drilling contractor. The basket,
98 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

which consisted of curved closely spaced flexible spring steel fingers 

attached to a steel ring, was inserted near the base of the cutting-shoe 

assembly, just above the cutting-shoe (fig. 2C). Above the basket 

was fixed a thin plastic sleeve that was slit at the top so it would 

collapse over the basket when the sediment began to slide out of the 

shoe and thus partially, or at times completely, seal the opening at 

the base of the sample tube. Excellent sample recovery was obtained 

with the basket-shoe. One hundred percent recovery of a 10-inch-long 

core, composed entirely of sediment having a consistency of thick 

gravy, was obtained at one sampling site. The nearly watertight seal 

formed by the collapse of the plastic sleeve over the basket made such 

recovery possible. The basket shown in figure 2<7, which has more 

widely spaced fingers made of heavier spring steel than the basket 

used in fine sediment, was designed for recovering sediments that have 

a high sand content.

Core recovery at sampling points where radioactivity was believed 

to be present throughout the full thickness of the river sediment generally ranged from 80 to 100 percent. Poor core recovery was accepted 

only where the sediment consisted of nearly pure sand or where soft 

mud was covered by a mat of leaves and twigs; there were few such 

localities.

Cores collected from the Clinch River were transferred from the 

metal sample tube of the Foil Sampler to a slightly larger plastic 

storage tube in the manner shown in figure 3. Because the plastic 

tube could be slipped over the sample tube, the core could be transferred, still encased in its foils, without sliding it through the entire 

length of plastic tube. After the cores were transferred, they were 

refrigerated to suppress biological and chemical action.
SEDIMENT SAMPLING, SWEDISH FOIL SAMPLER 99

FIGURE 3. Transferring sediment core to plastic tube for storage. Ends of foil 

strips that were cut off just below the piston are held in place by tape around 

the plastic tube. Sampler piston is lying on the deck. Ends of foil strips, left 

after core sample was cut off are seen projecting from the piston. Photograph 

by Oak Ridge National Laboratory.
SEDIMENT DEPOSITION FROM ATMOSPHERIC 

PRECIPITATION

By JAMES C. MUNDOEFP

ABSTRACT

The net sediment loss from an area may be less than, equal to, or greater than 

the sediment yield indicated by data on fluvial suspended-sediment yield per 

square mile. During 1954r-64, observations of sediment in atmospheric precipitation at Lincoln, Nebr., show that sediment concentrations in the rainwater 

were as high as 256,000 parts per million and sediment deposition of as much 

as 148 tons per square mile occurred as a result of precipitation in the Great 

Plains. For the drainage areas of some streams in the Great Plains, sediment 

deposition from precipitation may have exceeded sediment removal by streams 

in some years. The sediment budget of an area depends on the balance among 

the effects of wind, precipitation, and streams.

The terms "fluvial sediment," "suspended sediment," "suspendedsediment concentration," and "sediment deposition" are almost 

automatically associated with the work of streams; but these terms, 

as defined in many technical papers, also can be applied to sediment 

contained in or deposited from atmospheric precipitation. For example, "fluvial sediment" is "sediment that is transported by, is suspended in, or has been deposited from water" (Colby, Hembree, and 

Rainwater, 1956; Hubbell and Matejka, 1959).

Lincoln, Nebr., is in the glacial till and loess hills of eastern 

Nebraska and in the path of storms that generally move eastward 

across the central United States. West of Lincoln are the loess plains 

of central Nebraska and the loess hills of western Nebraska. To the 

south and southwest are loess deposits, shales (red beds) of Permian 

age in southern Kansas and northern Oklahoma, and rocks of Tertiary 

and Cretaceous age in semiarid southwestern Kansas, northern New 

Mexico, and southeastern Colorado. High wind velocity and wind 

erosion in semiarid areas to the west and southwest commonly result 

from pressure and wind systems that precede storms in eastern Nebraska. Large quantities of dust may be transported in an easterly 

direction from these areas. Some of this dust is "rinsed" from the 

atmosphere by precipitation. During 1954-64, some samples of 

precipitation were obtained at Lincoln, Nebr., when atmospheric conditions and weather forecasts indicated that appreciable sediment 

might be contained in the precipitation.

100
SEDIMENT DEPOSITION, ATMOSPHERIC PRECIPITATION 101

In eastern Nebraska, high-sediment rainfall or mudstorms are most 

common during the early spring months. All precipitation samples 

were obtained during March or April. These samples were collected 

in containers that were cleaned thoroughly immediately Hfore an 

expected storm. The samples were placed in glass bottles immediately 

after each storm; the dry weight of sediment was determin0*! in the 

laboratory. Sediment concentration, in parts per million (ppm), was 

computed for some samples. Precipitation for some storms v^as measured with a rain gage consisting of a glass funnel and a glass cylinder 

having only about one-twentieth of the cross-sectional area c f the top 

of the funnel.

On March 11,1954, total precipitation from a light shower was 0.03 

inch, and sediment concentration of the rainwater was 256,000 ppm. 

This concentration greatly exceeds any suspended-sediment concentration that has been observed in streams in Nebraska during field investigations from 1946 to 1964. Sediment deposition resulting from 

this precipitation was computed as 72 tons per square mile. The 

sediment in this precipitation was a brick-red color similar to that 

of the surface rocks of Permian age several hundred miles to the south 

and southwest.

On March 18, 1954, during the first 5 minutes of a light rain, the 

computed sediment deposition was 14 tons per square mile; during 

approximately 1 hour of intermittent light rain, the total sediment 

deposition was 38 tons per square mile.

On April 23, 1956, precipitation was 0.08 inch. Sediment concentration was 198,000 ppm, and sediment deposition was computed 

as 148 tons per square mile.

Precipitation reported as a "trace" at Lincoln on April 13, 1961, 

contained sufficient sediment to result in sediment deposition of 100 

tons per square mile.

During the period March 17-19, 1963, about 0.75 inch of precipitation resulted in sediment deposition of 36 tons per square mile. During the period March 15-18, wind velocities of as much as 80 miles per 

hour were reported in western Texas, northern New Mexico, and 

southwestern Nebraska. Sediment in this precipitation, as well as 

in most of the other observed precipitation that contained appreciable 

sediment, was light red. Significant areas of rocks of this color are 

not exposed within several hundred miles of the observation rite.

Sediment deposition from rainfall was about 30 tons per square 

mile on April 2, 1963; 28 tons per square mile on April 22, ] 963; 24 

tons per square mile on April 1, 1964; and 54 tons per square mile on 

April 12,1964.
102 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

The examples given probably represent only a minor part of the 

total sediment deposition by rain in Lincoln since 1954; an estimated 

average of 100-200 tons of sediment per square mile per year probably would be conservative for eastern Nebraska. Thus, while erosion 

by water is removing sediment from a given area, a combination of 

wind erosion in another area and of deposition by precipitation in 

the given area may result in net aggradation in a drainage basin. 

Water erosion tends to be concentrated in rills, gullies, and channels, 

and tends to remove sediment at a much faster rate from some parts 

of a drainage area than it does from other parts. Sediment deposition 

by precipitation tends to result in uniform deposition over the entire 

area on which the precipitation falls. The sediment in precipitation 

that falls on the drainage courses may be removed immediately by runoff through these courses, but much of the sediment in precipitation 

that falls on intervening areas may remain where deposited. Thus, 

during a period of several hundred or several thousand years, the 

relief would be increased not by water erosion alone but by water 

erosion in conjunction with sediment deposition by precipitation. 

Such deposition would tend to result in aggradation outside of drainage courses but would have no effect within the drainage courses.

Sediment that is originally suspended by wind and that is deposited 

by precipitation may be termed "fluvio-eolian." Deposition resulting 

from the described fluvio-eolian processes would be expected to have 

a different effect on relief than would deposition resulting from eolian 

processes only. Wind erosion and deposition, whether within a small 

area or over large regions, would be expected to decrease or subdue 

the relief. Removal of sediment by wind would be expected to be 

greatest from the highest and least protected topographic positions. 

Deposition of wind-transported sediment, in the absence of precipitation "rinse-out," would occur in wind-protected areas such as gullies, 

depressions, leeward slopes, and valleys. Thick loess deposits, such 

as those in the central United States, commonly show less relief than 

does the preloess surface. Thus, a tentative hypothesis is that the 

fluvio-eolian process results in increased relief, and eolian processes 

alone commonly result in decreased relief. *

The effect of precipitation-deposited sediment on the characteristics 

of soils is not known. Such sediment undoubtedly is of colloidal or 

near-colloidal size and would be subject to eluviation within a soil 

profile. In areas where sediment deposition by precipitation is 

significant, this sediment may contribute significantly to the formation 

or accretion of claypans or of less compact textural B horizons.

Data on suspended-sediment yield per square mile are not neces-
SEDIMENT DEPOSITION, ATMOSPHERIC PRECIPITATION 103

sarily indicative of net sediment loss from an area. Because of differences in climate and vegetation in different regions, an arid or 

semiarid region may supply the windblown sediment that results in 

a long-term net sediment gain in a humid or subhumid regien. Some 

representative annual suspended-sediment yields for streams in the 

Great Plains are shown in table 1. For the drainage areas of some

TABLE 1. Suspended-sediment yields, in tons per square mile, by years

Location

Little Arkansas River at Valley Center, Kans,

South Fork White River below White River, 

S. Dak,. .___ __._._ ......... .

1952

247

1953

303

1954

29

1955

341

1956

80

sfi

1957

239

482

78

1958

221

314

225

261

62

1959

41

231

84

585

1960

449

of the streams, sediment deposition by precipitation may have 

exceeded sediment removal by streams during some years. A distant 

arid or semiarid area may be supporting the suspended-sediment discharge of streams from a drainage basin in a humid or subhumid area. 

The sediment budget of an area depends on the balance among the 

effects of wind, atmospheric precipitation, and streams. The sediment budget in many arid and semiarid areas would show a net 

sediment loss; sediment is removed in such areas both by wind and 

by water, and little is received from other areas. The sediment budget 

in transition zones (some subhumid and semiarid areas) probably 

would show a cyclical fluctuation of gains and losses; the rate of longterm loss would be less than from an arid region. The sediment 

budget in some humid and subhumid areas may show a long-term 

gain; sediment deposition from precipitation may exceed the combined sediment loss from both wind and water erosion.

Factors in addition to climate and suspended-sediment yield of a 

specific area would have to 'be considered for a full understanding of 

the sediment budget of that area. The location of the area relative to 

sources of wind-transported sediment and to regional and global 

weather patterns is of major significance. Areas having similar 

amounts of precipitation could have markedly different sediment budgets depending on amount and seasonal distribution of precipitation, 

proximity to source areas of wind-transported sediment, characteristics of the wind-transported sediment, atmospheric circulation, storm 

paths, and all the factors commonly described as affecting erosion by 

water geology and soils, land use, vegetation, slope, maximum infiltration rate, and permeability. Further, areas having significantly 

different suspended-sediment yields may have similar sediment budgets 

if other factor affecting the sediment budget achieve a balance.
104 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

LITERATURE CITED

Colby, B. R., Hembree, C. H., and Rainwater, F. H., 1956, Sedimentation and 

chemical quality of surface waters in the Wind River basin, Wyoning: U.S. 

Geol. Survey Water-Supply Paper 1373.

Hubbell, D. W., and Matejka, D. Q., 1959, Investigations of sediment transportation, Middle Loup River at Dunning, Nebr., with application of data from 

turbulence flume: U.S. Geol. Survey Water-Supply Paper 1476.
USE OF SOIL-CONSOLIDATION TEST DATA TO 

DETERMINE PERMEABILITY OF CLAYS

By PAUL B. SEABEB and JOHN VECOHIOLI

ABSTRACT

Laboratory tests to determine the permeability of clays are done generally 

with a variable-head permeameter. Permeability may also be computed from 

consolidation-test data based on Terzaghi's theory of consolidation. For finetextured materials, permeability values obtained indirectly from consolidation 

tests commonly are smaller than those obtained from variable-head pertieameter 

tests, and they are probably more realible. It is suggested that consolidationtest data be used to supplement available permeability data and that consolidation test are a virtually untapped source of permeability data available to 

hydrologists.

During many ground-water investigations, it is necessary to make 

quantitative determinations of vertical movement of water through 

confining beds. The permeability of the confining bed, most often a 

clay in unconsolidated deposits, is one of the factors needed in determining the amount of vertical movement or "leakage" of water. The 

quantity of flow may be determined directly from the following 

formula, which is essentially a restatement of Darcy's law:

Q=kIA (1) 

in which Q = quantity of water discharged in unit time, 

&=the coefficient of permeability, 

/= hydraulic gradient, 

and A = the cross-sectional area through which the water flows.

The "permeability" of a porous medium describes the er-se with 

which a fluid will pass through it, and indicates its capacity for transmitting fluid under a differential head. "Permeability" is defined 

quantitatively as the specific property designating the rate or Tidiness 

with which a porous medium transmits fluids under standard conditions. The physical dimensions of the permeability unit will be 

determined by the equation used to express the flow. Permeability is 

expressed rationally by a coefficient that is independent of the fluid 

properties governing the flow. The specific permeability is commonly 

expressed in either centimeter-second units or Darcy units. These 

units are dependent upon the medium, but not upon the fluid that flows

105
106 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

through that medium. Some equations used for expressing the flow 

take into account the properties of the fluid so that proper measurements on a given medium will give the same permeability value for 

all fluids which do not alter the medium. In ground-water studies in 

the United States, where only one fluid is involved and where the 

centimeter-gram-second (cgs) units of measurement are not commonly 

used, the prevailing units of permeability are defined by properties of 

the water as well as of the medium and are referred to as Meinzer units 

(Wenzel, 1942, p. 9). To convert coefficients of permeability from 

Darcy units (cubic centimeters per second per square centimeter at a 

viscosity of one centipoise) to Meinzer units (gallons per day per 

square foot per unit hydraulic head at 60° F) one need only multiply 

by a factor of 18.2. To convert coefficients of permeability f xwn centimeter-second units (as commonly expressed in soils engineering) to 

Meinzer units at a temperature of 60° F, a factor of 2.1 X10* is 

employed. (See Wenzel, 1942, p. 9-10 for comprehensive listing of 

permeability units in use and factors for conversion into Meinzer 

units.)

Measurements of the permeability of rocks and unconsolidated 

materials may be made by either field or laboratory methods as 

described by Wenzel (1942). Laboratory determination of the 

coefficient of permeability are made by measuring the discharge or 

time rate of change in head for the percolation of measured quantities 

of water through a known area and volume of sample. Devices used 

for this purpose permeameters consist of a supply reservoir from 

which water is discharged through a percolation cylinder under either 

constant or variable head. The percolation cylinder is constructed 

with a fixed diameter and length, and is equipped with screens that 

support the sample and permit free inflow of water. Manometer 

tubes in the supply and receiving reservoirs are used to determine the 

loss of head that occurs for the vertical percolation of known quantities of water at measured rates through the sample cylinder. The 

variable-head permeameter is more suitable for tests on material of 

low permeability, such as clay, because the dimensions of the apparatus can be adjusted so that the measurements of head and time may 

be carried out with a high accuracy over a wide range of values.

A schematic representation of a variable-head perme<Mneter is 

shown in figure 1. The coefficient of permeability (k) may be calculated from the quantities measured during the test by mer-ns of the 

equation

, n n (LLi -, flo k==^At logl° AT ' (2)
CONSOLIDATION TEST, PERMEABILITY OF CLAYS 107

In this equation,

<z=the cross-sectional area of the manometer,

Z = the length of the sample,

J. = the cross-sectional-area of the sample,

£=the time,

and A0 , Ai = the original and final hydraulic heads, respectively. 

Equation 2 will give the coefficient of permeability expressed as the 

flow of water in cubic centimeters per second through a cross-sectional 

area of 1 square centimeter under a hydraulic gradient of 100 percent, 

if L is measured in centimeters and t in seconds. A, a, h0, and hi 

may be measured in any units, but a and A must be measured in 

the same units and h^ and hc must be in the same units.

The results of permeability tests may be misleading because of the 

difficulty of obtaining representative samples of material and placing 

them in the permeameter without disturbance. Some permeability 

tests also may be subject to various types of experimental error. One 

of the most important of these arises from the formation of a filter

ho'

Manometer 

/ area (a)

Sample 

area (A)

Valve

FIGUKE 1. Schematic representation of a variable-head permeameter. a, manometer area; A, 

sample area; h0 and hi, original and final hydraulic heads, 

respectively.
108 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

skin of fine material on the surface of the sample. In conducting 

permeability tests, the technician must be careful to saturate the 

sample completely and to make sure that no air bubbles will be 

released by the water during the test. The chemical character of 

the water used for the test should be compatible with the chemical 

character of the native pore water, if not, the clay-water system and 

the permeability values obtained will be affected. Samples obtained 

from depth may change in volume and structure during r,nd subsequent to the sampling operation. In addition, for a sample of very 

low permeability tested under no load in a variable-head perneameter, 

the disturbed condition at or near the container wall creates a boundary region which may produce a zone of higher permeability than 

the undisturbed sample matrix.

In consolidation tests, on the other hand, lateral pressure is created 

against the container walls and tends to reduce the permeability of 

the disturbed boundary region to approximately that of the sample 

matrix. In fact, none of the experimental errors listed above apply 

to consolidation tests.

Although consolidation tests are well known to engineer?, particuJarly those engaged in the construction industry, many hydrologists 

may not be aware of their uses. Consolidation tests are rm mainly 

to obtain data used in predicting the rate and amount of settling of 

structures founded on clay. However, permeability of the soil may 

be determined also from these data. Laboratory procedures using a 

consolidometer for consolidation tests are described by the U.S. 

Bureau of Reclamation (1960, p. 492-506) in a paper on the method 

of computing permeability from consolidation-test data.

The theory of consolidation, generally referred to as Terzaghi's 

theory of consolidation (Terzaghi, 1923, 1925, 1943), and its assumptions and limitations is discussed in all modern soil mechanics textbooks. (See "References.") In brief, when a saturated soil is subjected to a load, the load is almost entirely supported initially by the 

water in the pores because the water is incompressible relative to the 

soil material. The "excess hydrostatic pressure" created causes the 

water to drain from the pores, and the load is shifted to the soil 

structure. The escape of water takes place according to Darcy's law. 

This transfer of load is accompanied by a change in the volume of the 

soil equal to the volume of the water drained. Thus, corsolidation 

is the gradual process of volume reduction involving drainage, compression, and stress transfer. The rate at which the volume of the 

soil changes in relation to an applied load is directly related to the 

permeability of a soil because the permeability controls the rate at 

which the pore water can escape. Hence, a certain load increment
CONSOLIDATION TEST, PERMEABILITY OF CLAYS 109

produces a change in void ratio at a rate governed by the permeability 

of the soil. For sands, the permeability is so high that the time 

required for consolidation is considered negligible. For clays, the 

rate of volume change after the application of a load increment is 

important and consolidation laboratory studies are almost entirely 

limited to clays.

The coefficient of permeability of a sample for any given load 

increment is obtained from the equation :

l+e0 

where

k= coefficient of permeability, in centimeter per second,

cv coefficient of consolidation, in square centimeter 

per second,

7a,=unit weight of water, or 1 gram per cubic centimeter,

A,= coefficient of compressibility, in square centimeter

per gram, 

and

e0= initial void ratio.

A, is defined by the expression:

A,=jF^ "i "o (4) 

where 60= void ratio at pressure P0, and 0i=void ratio at pressure 

PI, pressure being in grams per square centimeter.

The coefficient of consolidation is always given in the teit results 

and, therefore, the method of computing cv need not be discussed.

Consolidation test results are commonly expressed graphically 

(fig. 2). The upper curve (A) in figure 2 is a plot of void ratio against 

pressure. The lower curve (B} is a plot of the coefficient of consolidation against pressure. These curves are all that are necessary to 

compute permeability from equation 3.

The following example illustrates the computations:

1. From figure 2, e0 =0.860 at P0 =250 g per sq cm and 0i=0.852 

at PI =500 g per sq cm.

2. Substituting in equation 4,

A 0.860-0.852 OOXX1A , A= 500-250 =3 '2 X10-6 sq cm per g.

7*6-504 O 66 8
110 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

3. c, for this load increment as obtained from the lower curve (B) 

of fig. 2=78X10~4 sq cm per sec.

4. Substituted in equation 3,

, 78X10~4 X1X3.2X1Q-5 

1.860 = 1.34X10 7 cm per sec (or, using

the conversion factor of 2.1 XlO4, the permeability may be 

expressed as 2.8X10"3 Meinzer units).

5. Therefore, 1.34X10"7 cm per sec is the permeability at the void 

ratio 0.856 (the average void ratio for this load increment).

0.86

0.82

p 0.78

0.74

0.70

0.66

\

\

rFICIENT OFCONSOLIDATION SQUARE CENTIMETERS PER A oo 

o o

 ~- 

- -

- - *

* 

^

X

X

> "- . . 4 <

1 0.25 0.5 1 2.5 5 1

8 =

PRESSURE, IN KILOGRAMS PER SQUARE CENTIMETER

FIGITBB 2. Relation of pressure to void ratio (curve ./I) and coefficient of 

consolidation (curve B). Modified from Lambe, 1951, p. 87, fig. IX-12.
CONSOLIDATION TEST, PERMEABILITY OF CLAYS 111

Values of permeability are then plotted against the average void 

ratio for each load increment (fig. 3). The plot of e against Iogi0 k 

is a straight line, and therefore only two points should be required. 

However, it is advisable to use as many increments of load as were 

run in the consolidation test to arrive at the best fit for the line. The 

field permeability may then be estimated from this graph by using the 

field void ratio and obtaining the corresponding permeability value 

(point X on fig. 3). The field void ratio may be computed either 

from a direct determination using the sample material or from the 

e-log p curve if the overburden pressure is known (Peck ard others, 

1953, p. 18-27, 58-63, Y2-86).

Foundation engineers, in dealing with small areas of clay, generally 

are interested only in total volumes of water, and for fine-textured 

materials a difference in the coefficient of permeability of af much as 

1,000 times in these low ranges quite likely would not be critical. The 

U.S. Bureau of Reclamation (1960, p. 63) states:

* * * Permeability in some soils is very sensitive to small changes in density, 

water content or gradation. In certain ranges, a few percent variation in any 

one of these factors may result in a few thousand percent variation in permeability. Because of the wide variation in permeability that is possible, measurement of great accuracy is not required for designs; rather the order of magnitude of the permeability is of importance.

However, in ground-water investigations dealing with movements 

of water between aquifers over broad areas for considerable periods of 

time, relatively minor differences may be quite significant. Accord0.88

0.84

0.80

Q

O 0.76

0.72

0.68

IxlO-7 

PERMEABILITY (Ic), IN CENTIMETERS PER SECOND

FIQTJEE 3. Relation of permeability (fc) to void ratio (e).
112 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

ingly, the most reliable method of determining permeability should be 

used for these investigations. Soil mechanics and foundation engineering textbooks (for example, Peck and others, 1953, p. 55; and 

Terzaghi and Peck, 1948, p. 48) state that the permeability of clay 

samples can be determined most accurately indirectly from data 

obtained from consolidation tests.

No published reference is known to the authors in which permeabilities obtained from consolidation tests and from variable-head 

permeameter tests on the same sample are compared, though such 

research is planned by the Hydrologic Laboratory, U.S. Geological 

Survey, Denver, Colo. Variable-head permeameter tests on many 

samples of fine-textured material from the Coastal Plain in New Jersey 

have yielded permeability values that are consistently greater than 

those one might expect on the basis of generally accepted permeability values for clay obtained from consolidation-test data. Meager 

comparative data consisting of permeability values determined by 

both methods on different samples of a relatively uniform lithologic 

unit suggest differences as great as 10,000 times. Johnson and Morris 

(1962, p. 48-51) found that for samples from the Los Banof-Kettleman City area in California, the coefficients of permeability for the 

clayey sediments of low permeabilities (&<0.01-0.001 in Meinzer 

units) tested in the variable-head permeameter in general appear to be 

in a considerably higher range than those computed from consolidation tests for samples of similar texture. They concluded that because 

of the expansion resulting from release of overburden pressure, those 

permeabilities obtained from consolidation tests on samples from considerable depths are more reliable than those obtained from the variable-head permeameter.

Consolidation-test data may be obtained from numerous sources, 

among which are large construction companies, engineering firms and 

consultants, State highway departments, the U.S. Bureau of Reclamation, the U.S. Bureau of Public Roads, the U.S. Corps of Engineers, 

and the Geological Survey's Hydrologic Laboratory. It is not suggested that computations of the permeability of clays from consolidation tests entirely replace determinations by the variable-head 

permeameter method. Rather, consolidation-test data can be used 

to supplement available data obtained by the variable-head permeameter method. It is suggested that consolidation tests are a virtually 

untapped source of permeability data available to hydrologies.

REFERENCES

Johnson, A. I., and Morris, D. A., 1962, Physical and hydrologic properties of 

water-bearing deposits from core holes in the Los Banos-Kettleman City 

Area, California: U.S. Geol. Survey open-file rept, 182 p.
CONSOLIDATION TES.T, PERMEABILITY OF CLAYS 113

Lambe, T. W., 1951, Soil testing for engineers: New York, John Wiley & Sons,

Inc., p. 74-87. 

Peck, R. B., Hanson, W. E., and Thornburn, T. H., 1953, Foundation engineering:

New York, John Wiley & Sons, Inc., 410 p. 

Taylor, D. W., 1948, Fundamentals of soil mechanics: New York, John Wiley &

Sons, Inc., 700 p. 

Terzaghi, Karl, 1923, Die Berechnung der Durchlassigkeitsziffer des Tones aus

dem Verlauf der Hydrodynamischen Spannungserscheinungen: Akademie

der Wissenschaften in Wien, Sitzungsberichte, Mathematishnaturwissenschaftliche Klasse, v. 132, pt. Ha, %, p. 125-138.

 1925, Principles of soil mechanics Settlement and consolidation of clay: 

Engineering News-Record, November, p. 874-878.

 1943, Theoretical soil mechanics: New York, John Wiley & Sons, Inc.,

510 p. 

Terzaghi, Karl, and Peck, R. B., 1948, Soil mechanics in engineering practice:

New York, John Wiley & Sons, Inc., 566 p. 

U.S. Bureau of Reclamation, 1960, Earth Manual: Washington, U.S. Govt.

Printing Office, 751 p. 

Wenzel, L. K., 1942, Methods for determining permeability of water-bearing

materials: U.S. Geol. Survey Water-Supply Paper 887, 192 p.
TWO SIMPLIFIED VARIATIONS OF A METHOD FOR 

COMPUTING GROUND-WATER PUMPAGE

By GEOBGE W. SANDBERQ

ABSTRACT

Ground-water pumpage can be calculated by either of two modifications of a 

previously published method of computing pumpage in less time than was required by the published method. Calculated pumpages were within 2 percent 

of the amounts measured by totaling-type flow meters in two ground-wster basins 

in southwestern Utah.

INTRODUCTION

This paper describes two time-saving modifications of a previously 

published method (Waite and others, 1954, p. 17-19) of computing 

total ground-water pumpage from a ground-water basin. / Ithough 

the previously published method and the modifications described here 

are for pumps that are powered by constant-speed electric motors, they 

can be adapted to pumps that use other power.

VARIATION 1

The first step in planning a pumpage inventory of a ground-water 

basin is to assign wells into groups, according to location and the 

characteristics of the wells and of the hydrologic environment. These 

characteristics include depth of the wells, water-bearing strata tapped, 

faults or other hydrologic barriers within the basin, and the general 

magnitude of the depth to water and of the water-level fluctuations 

during the pumping season.

Two representative wells are chosen from each group at the beginning of the pumping season. Two wells are chosen, in case cne is inoperative during part of the season. The discharge of the representative wells is measured at least five times at about equal interval^ during 

the pumping season to determine any change. Because the other wells 

in each group have similar characteristics, the discharge rates of the 

wells in a given group should change in direct proportion to the n.casured change in discharge rate of the representative wells. Measurements of the other wells are made about the middle of the pumping 

season; the representative wells should be measured at the same time. 

114
COMPUTING GROUND-WATER PUMPAGE 115

Power input to the pumping plant is measured each time the discharge is measured. The power input is measured by observing the 

time, t, in seconds, that the watt-hour meter disk requires for a given 

number of revolutions, n, then applying the formula

, , Z.QXkhXMXn kwhr ; 

where

kwhr=kilo watt-hours,

ArA=disk constant on the meter nameplate or on the disk,

and

M=the product of the current transformer ratio and the potential transformer ratio (M is 1, where transformers are 

not used with the electric meter).

The number of kilowatt-hours required to pump an acre-foot of 

water (kwhr per acre-ft) is computed each time the discharge of any 

of the wells is measured by using the equation kwhr per acre-

,, 5,430 kwhr , ~ . ,, ,. , n * ft= ft > where Q is the discharge in gallons per minute.

The values for at least one of the representative wells in each group 

of wells are plotted on rectangular coordinate paper versus date of 

measurement to obtain a rating curve for the group. A typicr.l rating 

curve is shown in figure 1.

The next step is to determine the average number of kilowatJt-hours 

used during the season by each pump to pump an acre-foot of water. 

This determination is made by relating the number of kilowatt-hours 

used by each pump during each month (this number can be obtained 

from the power company) to the rating curve for the pump, as shown 

in figure 1, and ascertaining the date when half the total k; lowatthours were used (the kilo watt-hours are assumed to be used at a uniform rate throughout the month). The number of kilowatt-hours 

used to pump an acre-foot of water will be horizontally to the left of the 

point where the date intersects the curve. For a pump of a representative well, this value is the average number of kwhr per acre-ft ured during the pumping season; for all other pumps, it is an index of the average number of kwhr per acre-ft. The average number of k^hr per 

acre-ft for the other pumps is computed by means of a proportion in 

which the average number of kwhr per acre-ft for a given well, in relation to the index value, is equated to the measured number of kwhr per 

acre-ft used by the pump in question, in relation to the measured 

kwhr per acre-ft used by the representative well.
116 TECHNIQUES, WATER RESOURCES INVESTIGATIONS, 1965

Q

£ Pump

1 l p

1

UJ |

5 114 

5 112

U0 110 

§ 108 

S 106 

o 104 

a 102

UJ °- 100

Q 

uj go

13 

(/I

9§ 94 

I 92 

5 90

0 88

5 86

Kilowatt-hours used pe 

1 6830 5210 1 6360

ump 2 3960 2870 

1 Pump 3 10,200 10,110 10,090

i

1 

H 

1

1

T~l 1

l"124

r

105.5

 o 

May

Pump

Pump 1-

s - -a"

June

 

/

, \L

//

/

July

month Totals 

8090 2590 29,080

r-8450 1690 16,970 

11,600 8850 4420 55,270

l-Pump 2

3

/

/

/

f^

-^^^X

/

jyS^

^

___ -

Points where one-half of 

^^season's kilowatt-hours 

/ were used

o Pump 1 measured 

© Pumps 1, 2, and 3 measured

August September Octot<?r

FIGURE 1. Curve showing pumping-season change in the power consumptiondischarge ratio in one well, and monthly power consumption and estimated 

midpoints of seasonal power consumption in this well and two related wells.

To illustrate the procedure, assume that a ground-water basin contains three wells, all having the same general characteristics, and that 

the field measurements and computations have been made ard a rating 

curve drawn (fig. 1). Note that the rating curve was prepared by 

drawing a smooth curve through points representing the number of 

kwhr per acre-ft measured on six dates at intervals of P<-4 weeks. 

The dashed vertical lines are drawn on the dates on which half the 

annual power consumption was used by each pump. Froir the point 

of intersection of the dashed vertical lines with the rating curve, the 

dashed horizontal lines indicate the index kwhr per acre-ft of the 

pumps. The values obtained from figure 1 for each pump are given in 

the following table. The index kwhr per acre-ft is ih°> average 

kwhr per acre-ft for the representative pump (No. 1). For pump 

2 the average kwhr per acre-ft is a ratio of the measured kwhr per 

acre-ft of pump 2 to the measured kwhr per acre-ft of pump 1 on the 

same date, multiplied by the index kwhr per acre-ft of pump 2. For 

pump 2, the average kwhr per acre-ft is

124

98 X 103.5, or 131.
COMPUTING GROUND-WATER PUMPAGE 117

By the same procedure, the average kwhr per acre-ft for pump 3 is

105.5

-jr^-X 98.4, or 105.9

Pump

1.. ................... .......

Z.. ..........................

S.. ..........................

Measured

kwhr per

acre-ft on

July 23

98

124

105.5

Date on which

half the power

had been

consumed

July 12 

Aug. 6.... 

July 24 ...

Index kwhr

per acre-ft

93.4

103.5

oa d

Average

annual kwhr

per acre-ft

93.4

131

105.9

Annual

pumpage

(acre-ft)

311

129

522

The total seasonal pumpage is obtained by dividing the seasonal 

power consumption in kilowatt-hours by the average seasonal kwhr per 

acre-ft. The seasonal pumpage from wells 1, 2, and 3 is 311,129, and 

522 acre-feet, respectively, a total of 962 acre-feet from the basin. In 

actual practice the accuracy of the method does not warrant reporting 

the pumpage figures more precisely than the nearest 10 acre-feet in the 

range above, but for purposes of instruction the figures have not been 

rounded.

VARIATION 2

The variation-1 method of computing ground-water pumpage can 

be simplified for use in succeeding years with only a slight diminution 

of accuracy. The kwhr per acre-ft is determined for each of the wells 

in the basin on or near the date which represents the half-wr,y point 

of power consumption in the basin. This calculated value is assumed 

to be the average kwhr per acre-ft. The total power consumption of 

each pump is divided by the calculated kwhr per acre-ft of that pump to 

determine pumpage. The pump must be used throughout the season, 

however, if only one measurement is used as an average. In the above 

illustration, had only one measurement of kwhr per acre-ft been made 

for each pump, the computed total pumpage would have b^en 914 

acre-feet for the three wells. This is within 5 percent of the total computed by using the rating curve.

The pumpage from two ground-water basins in southwestern Utah 

as computed by the method described herein was within 2 percent of 

the pumpage registered by totaling-type flow meters. The apparent 

excellent accuracy and the savings in time warrant the use of this 

method in preference to the method of Waite and others (1954, 

p. 17-19).

REFERENCE CITED

Waite, H. A., Nelson, W. B., Lofgren, B. F., Barnell, R. L., and Butler, R. G., 1954, 

Status of ground-water development in four irrigation districts in southwestern Utah: Utah State Engineer Tech. Pub. 9, p. 5-93.

U.S. GOVERNMENT PRINTING OFFICE: 1966 O 796-J 04