Variations in the 

Chemical Character of the 

Susquehanna River at 

Harrisburg, Pennsylvania

GEOLOGICAL SURVEY WATER-SUPPLY PAPER 1779-B

Prepared in cooperation with the Pennsylvania Department of Forests and 

W^aters and the Pennsylvania Department of Commerce
Variations in the 

Chemical Character of the 

:usquehanna River at 

4arrisburg, Pennsylvania

> PETER W. ANDERSON

( NTRIBUTIONS TO THE HYDROLOGY OF THE UNITED STATES

10LOGICAL SURVEY WATER-SUPPLY PAPER 1779-B

^-repared in cooperation with the Penn- 

>lvania Department of Forests and 

T/raters and the Pennsylvania Depart- 

' e.nt of Commerce

.;TED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1963
UNITED STATES DEPARTMENT OF THE INFERIOR 

STEWART L. UDALL, Secretary

GEOLOGICAL SURVEY 

Thomas B. Nolan, Director

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

Washington, D.C. 20402
CONTENTS

Page

Abstract __________________________________________________________ Bl

Introduction ______________________________________________________ 1

Purpose and scope-_-----_---_-_---___-____-____________-_-____ 2

Location_____________________________________________________ 2

Available data__--_---_-__-____________-__-________---_-______ 4

Chemical characteristics.___________________________________________ 6

Environment and chemical quality_____________________________ 10

Streamflo w_ ______________________________________________ 10

Coal-mine drainage._______________________________________ 10

Geologic influences_-_-____-_____--__-___________-__________ 16

Conclusions...____________________________________________________ 17

References______________________________________________________ 17

ILLUSTRATIONS

Page

FIGURE 1. Cross-section sampling stations _____________________ __ B3

2. Cross-section diagram____________________________________ 4

3. Average bicarbonate-and sulfate-ion concentrations.______ 7

4. Specific conductances--_______-_--____-_____________.____ 9

5. Susquehanna River basin_________________________________ 11

6. Sulfate- and bicarbonate-ion concentrations-...--___________ 13

TABLES

Page

TABLE 1. Percent of days in which physical and chemical properties were 

equaled or exceeded, Susquehanna River at Harrisburg, Pa., 

stationE. 1180_________________________ B5

2. Maximum, average, and minimum observed values for specific 

conductance, pH, and chemical analyses, Susquehanna River 

at Harrisburg, Pa., October 1956 to September 1960 (based 

on once-a-month sampling) _________________________.___ 8

3. Physical and chemical character of mine drainage from anthracite coal fields, collected June 25,1959___________________ 12

4. Chemical analyses, in parts per million, at sampling stations1

in the Susquehanna River basin, Pennsylvania__________ 14

5. Chemical analyses, in parts per million, at cross-sectior 

sampling locations on the Susquehanna River in Pennsylvania, collected July19,1961____________________________ 15

m

CONTRIBUTIONS TO THE HYDROLOGY OF THE UNITED STATES

VARIATIONS IN THE CHEMICAL CHARACTER OF THE 

SUSQUEHANNA RIVER AT HARRISBURG, PENNSYLVANIA

By PETER W. ANDERSON

ABSTRACT

The chemical quality of the Susquehanna River at Harrisburg is influenced 

by three major factors: streamflow, anthracite and bituminus coal-mine drainage, 

and geology. Water samples collected at Harrisburg near the west bank of the 

Susquehanna River and those of western tributaries that drain limertone terranes are similar in chemical quality. The water is alkaline and contains calcium, magnesium, and bicarbonate-ion concentrations typical of water drained 

from limestone. The chemical quality of water samples collected in the center 

of the river resembles the quality of the West Branch Susquehanna Rivsr, which 

has a dissolved-solids content of about 200 parts per million, and a sulfate-ion 

concentration that generally exceeds the bicarbonate-ion concentration. Samples 

collected near the east or Harrisburg bank show the effect of anthracite coalmine drainage from the river's eastern tributaries. The pH of these, samples 

ranges from 5.7 to 7.5, and sulfate is the predominate ion.

The dissolved-solids content of the river at the Harrisburg cross-section stations is inversely proportional to the streamflow. During periods of low riverflow, the dissolved-solids content approaches a maximum; during periods of high 

flow, the content is low.

The chemical composition of the river at the Harrisburg cross section indicates 

that water from the principal tributaries above Harrisburg does not mix sufficiently to lose its chemical-quality identity before reaching Harrisburg irrespective of the long distance involved, the many islands and bridge piers, and the 

rough streambed. This lack of lateral mixing is probably due to the small 

depth-width ratio and the extreme width of the river.

INTRODUCTION

A reconnaissance of the Susquehanna Eiver at Harrisburg in 1944 

indicated a wide variation in chemical quality across the width of the 

river. Because a single sample would not be representative of the 

water quality of the river, the U.S. Geological Survey, the Pennsylvania Department of Forests and Waters, and the PennFylvania 

Department of Commerce cooperated to investigate the variations in

Bl
B2 CONTRIBUTIONS TO THE HYDROLOGY OF THE UNITED STATES

chemical quality of the river from bank to bank. Samples generally 

were taken at six stations in the cross section on the T;Valnut Street 

bridge in Harrisburg.

PURPOSE AND SCOPE

This report describes the variations in chemical quality of the Susquehanna Kiver at Harrisburg, discusses the causative factors involved, and shows how they influence the chemical character of the 

river. The Harrisburg location was selected for study because of its 

marked cross-section variation in chemical quality and because of the 

considerable interest in the chemical quality of the river water, shown 

by representatives in the fields of water management and public water 

supplies.

This report summarizes the data collected during the period 1944-60 

at the Harrisburg location. Variations in the chemical quality across 

the river are described in terms of these data. A qualitative interpretation of the chemical analyses collected at several locations on the 

Susquehanna River main stem and its tributaries shows the effects of 

physiographic, hydrologic, and cultural environment on the chemical 

character of the river at Harrisburg.

LOCATION

The Susquehanna River originates in Otsego Lake in southeastern 

New York State, enters Pennsylvania near Lanesboro, Susquehanna 

County, reenters New York State near Great Bend, Pa., and then reenters Pensylvania near Sayre, Bradford County. From the Pennsylvania-New York State line, the river flows southward through 

central Pennsylvania to the Chesapeake Bay. The drainage basin of 

the entire river is 27,655 square miles, three-fourths of it within 

Pennsylvania.

The cross-section sampling stations are on the Walnut Street bridge 

connecting the capital city of Harrisburg, Dauphin County, and the 

borough of Lemoyne, Cumberland County (fig. 1). Harrisburg is 

69 miles from the mouth of the river and 353 miles from its headwaters. At the sampling station, City Island divides the river into 

east and west channels. At median flow the gross widths of the east 

and the west channels are 1,288 and 1,330 feet, respectively

The Susquehanna River at the sampling station has a drainage 

area of 24,100 square miles. The median flow for the period 1891-1959 

was about 20,000 cfs (cubic feet per second). A cross-section diagram 

of the east and west channels at the Walnut Street bridge shows the 

relative depth of the river at median flow (fig. 2). The. depths at the 

cross-section sampling stations are shallow, ranging at median flow 

from 3.9 feet at station W. 1320 to 9.3 feet at station E. 600.
CHEMICAL CHARACTER OF SUSQUEHANNA RIVER B3

Sampling Station

O 120

Station Number

600 0 600 1200 1800 2400 FEET iii i i i i

FIGURE 1. Location of chemical quality cross-section sampling stations, Susquehanna

River at Harrisburg, Pa.
B4 CONTRIBUTIONS TO THE HYDROLOGY OF THE UNITED STATES 

WEST EAST

EAST CHANNEL

2

4

6

. 8

j j

'10

o.

UJ

Q WEST CHANNEL

1400 1200 1000 800 600 400 200 0 

WIDTH OF CHANNEL, IN FEET

FIGURE 2. Cross-section diagram of depth in the east and wes*: channels of the 

Susquehanna River at Harrisburg, Pa., on October 31, 1958.

AVAILABLE DATA

From October 1944 to September 1946, the Susquehanna River 

was sampled from 1 to 3 times a month at each of 11 sampling sites 

on the Walnut Street bridge at Harrisburg. In October 1946, the 

number of sampling sites was reduced to six, three ir each channel. 

In the east channel, samples were usually collected at 95,575, and 1,155 

feet from the east or Harrisburg bank, and in the w^st channel at 

563,1,063, and 1,283 feet from the west bank of City Island.

Chemical analyses of each sample consisted of the determination 

of color, pH, specific conductance, bicarbonate, sulfate, chloride, 

nitrate, and hardness. The results of these chemical analyses from 

1944 to 1951 were reported by W. F. White (1947 and 1951) and N. H. 

Beamer (1953). These publications of the Pennsylvania Department 

of Commerce contain graphs and brief comments on the Harrisburg 

stations.

From October 1944 to September 1946, daily water samples were 

collected at the east channel station E. 1180. The water of this station
CHEMICAL CHARACTER OF SUSQUEHANNA RIVER B5

location was representative of the quality of raw water used by the 

former city waterworks on City Island. Temperature, pH, and specific conductance were measured on each sample. The daily samples 

for each month were composited into three 10-day samples, and a comprehensive analysis was made of each. The comprehensive analysis 

included the determination of color, pH, specific conductance, silica, 

iron, calcium, magnesium, sodium, potassium, bicarbonate, sulfate, 

chloride, fluoride, nitrate, dissolved solids, and hardness.

Results of the chemical-quality studies at the daily sampling station 

E. 1180 are summarized in a report entitled, "The Chemical Quality 

of Surface Water in Pennsylvania" (Durfor and Anderson, 1963). 

The tabulated summary of chemical analyses at this station is given 

in table 1. The table was prepared by the following methods: (1) 

frequency distributions of daily temperature, pH, and specific conductance values were determined; (2) relations were establirhed between the specific conductance and the concentration of individual 

dissolved constituents of composite samples; and (3) on the basis of 

these empirical relations between specific conductance and ion concentration and the frequency distribution of specific conductance, the frequency distribution of several chemical constituents was estimated.

TABLE 1. Percent of days in which physical and chemical properties were equaled 

or exceeded, Susquehanna River at Harrisburg, Pa., station E. 1180, October 

1944 to September 1946

[Analyses by U.S. Geol. Survey]

Temperature (°F) ___________

TT

Specific conductance (micromhos at 

25 °C)_.___. .___._.____...______

Chemical analyses in parts per million: 

Calcium (Ca)_ ________________

Magnesium (Mg) __ ___ _ ____

Sodium and potassium (Na+K)__ 

Bicarbonate (HCO3) ________

Sulfate (SOO- ----- -----

Chloride (Cl)________ _ _______

Residue on evaporation at 180 °C_ 

Calcium, magnesium hardness as 

CaCOa ... _

1 

percent

7Q

7.5

369

40

14

14 

48

126

9.0

244 

156

10 

percent

75

7.2

278

30

10

10 

40

90

6.4

170 

114

60 

percent

55

6.9

180

20

5.9

6. 1 

26

54

4. 2

110 

73

90 

percent

34

6.6

105

12

3.0

3.0

18

28

2.4

64 

42

09 

percent

32

6.2

88

10

2.2

1.4 

16

21

2.0

54 

34

Compilations of the chemical-quality data collected in Pennsylvania 

since 1944 are published by the Geological Survey in the WaterSupply Paper series entitled "Quality of Surface Waters of the. United 

States, Parts l^i, North Atlantic Slope Basins to St. Lawrence River 

Basin." The chemical quality of the Susquehanna River at Harrisburg was discussed by W F. White (1949) in a paper presented at a 

meeting of the Engineers' Society of Western Pennsylvania.

695-897 63 2
B6 CONTRIBUTIONS TO THE HYDROLOGY OF THE TNITED STATES

CHEMICAL CHARACTERISTICS

The principal dissolved constituents in the Susquehanna River water 

at Harrisburg are calcium, magnesium, sodium, silica, bicarbonate, 

sulfate, chloride, and nitrate. Smaller quantities of other constituents, such as potassium, iron, manganese, and fiuoride are also present. 

The river water generally contains less than 200 ppm (parts per million) of dissolved solids at station E. 1180 and W. 1320 and less than 

325 ppm at station E. 120. The dissolved-solids content was estimated from the specific conductance. For water from the Susquehanna River at Harrisburg, the dissolved-solids content is approximately 0.62 ±0.02 of the specific conductance.

To demonstrate the variations in chemical quality from bank to 

bank, a tabulation of the maximum, average, and minimum observed 

values for specific conductance, pH, and chemical analyses, based on 

once-a-month sampling at the cross-section stations (October 1956 to 

September 1960), is presented in table 2. This period is chosen for 

tabulation because of the availability of consecutive monthly data.

The average sulfate and bicarbonate-ion concentrations compiled in 

table 2 are plotted in figure 3 to demonstrate the variations in concentration of these ions across the river. The bicarbonate ion decreases 

in concentration from 113 to 19 ppm in a west to east direction, and 

the sulfate ion increases in concentration from 24 to 131 ppm. The 

maximum hydrogen-ion concentration (pH) decreases from 8.5 to 

7.5 (table 2). The hardness of water is low near th?. center of the 

river and increases toward the banks (table 2). The hardness near the 

east bank results from the presence of calcium sulfate. Near the 

west bank the hardness is the result of the presence of calcium 

bicarbonate.
MILLION PER PARTS IN CONCENTRATION, 

o

o 2. 

oo 

o

\

-W1320

iff

-W600

ro 

o

W1100

o

01 

(0

1 

ET Su

180 El ^- 

E120

B

o

=T 

01

Cft

aaiovavno &o HHAIH
B8 CONTRIBUTIONS TO THE HYDROLOGY OF THE UNITED STATES

TABLE 2. Maximum, average, and minimum observed values for specific conductance, pH, and chemical analyses, Susquehanna River at Harrisburff, Pa., 

October 1956 to September 1960

[Analyses by U.S. Geol. Survey. Based on once-a-month sampling]

Specific conductance (micromhos at 

2500)_-.._._....._...___..._.___.__

pH.. ._.._____. _.__ __ ... __ .....

Chemical analyses (parts per million):

Bicarbonate (HGOs) ______

Sulfate (SOO....................

Chloride (Cl).... _ ... ____

Nitrate (NOa)----. __ ........

Hardness as CaCOs: 

Calcium, magnesium .......

Noncarbonate _______

Specific conductance (mlcromhos at 

25°C) .._. .- . -, - 

pH.. ........ .....................

Chemical analyses (parts per million):

Bicarbonate (HCOa) _

Sulfate (BOO-- - 

Chloride (Cl) _ . __ ...........

Nitrate (NO»).. ................

Hardness as CaCOj:

East channel

E. 120

Maximum

610 

7.5

0 

34 

301 

24 

8.8

264 

256

Average

333

0 

19 

131 

8.0 

3.5

139

124

Minimum

142 

6.7

0 

5 

36 

2.0 

.6

54 

28

E.600

Maximum

488 

8.2

0 

56 

229 

23 

4.7

186 

171

Average

260

0 

36 

83 

83 

2.4

103 

74

Minimum

103 

6.0

0 

16 

23 

2.5 

.2

38 

23

E. 1180

Maximum

391 

8.6

4 

64 

127 

17 

4.7

172 

120

Average

197

0 

30 

68 

5.6 

2.2

77 

52

Minimum

96 

6.1

0 

8 

20 

2.0 

.7

38 

10

West channel

W. 600

Maximum

306 

7.9

0 

96 

101 

21 

4.1

152 

95

Average

192

0 

36 

51 

5.9 

2.0

75 

45

Minimum

92 

6.1

0 

6 

21 

.6 

.5

35

5

W. 1100

Maximum

377 

8.0

0

124 

72 

19 

6.7

136 

73

Average

220

0 

72 

37 

6.8 

3.0

87 

28

Minimum

109 

6.4

0 

20 

16 

1.0 

.3

40 

13

W.1320

Maximum

360 

8.5

4 

169 

38 

19 

10

160 

32

Average

255

0 

113

24 

7.7 

5.8

114

22

Minimum

113

6.6

0 

16 

17 

3.0 

.2

40 

10

A comparison of bicarbonate, and sulfate-ion concentrations 

plotted in figure 3 for the 4-year periods 1956-60 and 1945-19 indicates 

that the river water has changed little during the period of data collection. The mean discharge for the period 1956-60 (34,910 cfs) is 

slightly less than the mean discharge for the period 1945-19 (35,320 

cfs). This slight difference in discharge accounts for the slightly 

lower bicarbonate and sulfate concentrations during the 1945-49 

period.

The variations in specific conductance and, therefore- the dissolvedsolids content from bank to bank are shown in figure 4. For both the 

high and the low discharge rates, the specific conductance is higher 

near the banks than in the center. The higher conductance values are 

near the east or Harrisburg bank for both discharge rates. A com-
MICROMHOS IN CONDUCTANCE, SPECIFIC 

CENTIGRADE 25° AT 

00

MOO *»-o OF INDTHCHANNEL, 

i(F_, hlgh

EET ie

8

V

W600

W1320

W1100

m

O

d-E1180

k E120

H3.LOVHVHO HHAIH
BIO CONTRIBUTIONS TO THE HYDROLOGY OF THE UNITED STATES

parison of the specific conductances compiled in table & indicates that 

this same relation occurs for maximum, average, and minimum 

observed values and, thus, probably occurs at most discharge rates.

ENVIRONMENT AND CHEMICAL QUALITY

The chemical character of the Susquehanna River at Harrisburg is 

influenced by three major factors: streamflow, anthracite and bituminous coal-mine drainage, and geology. Most of the tributaries draining into the west side of the river contain high concentrations of 

calcium and bicarbonate ions, in relation to other constituents. Many 

of the tributaries on the east side contain high concentrations of calcium and sulfate ions. The incomplete mixing of the calcium bicarbonate and calcium sulfate waters produces the cross-section variations 

at Harrisburg.

A map of the central Susquehanna River basin showing many of 

the tributaries and sampling points is presented in figure 5.

STREAMFLOW

Streamflow is composed of water that reaches the stream by direct 

overland flow and by ground-water inflow. After periods of moderate to heavy precipitation, the major part of the water flowing in a 

stream is the result of direct overland flow. Base flow is composed 

largely of ground-water inflow. During periods of base flow, the 

dissolved-solids content of the Susquehanna River is at a maximum, 

as the chemical quality of the river represents the effect of groundwater inflow and coal-mine drainage. As streamflow increases, the 

dissolved-solids content is lowered by dilution from direct runoff. 

The decrease in dissolved-solids content with increase in flow can be 

shown using the specific conductance of station E. 1180 as a measurement of the dissolved-solids content. During the period 1956-60, the 

maximum specific conductance, based on a once-a-month sampling, 

was 391 micromhos on September 16, 1957, and the discharge on this 

date was 3,580 cfs. On February 15, 1960, the specific conductance 

was 96 micromhos, and the discharge was 91,000 cfs.

COAL-MINE DRAINAGE

Several tributaries to the Susquehanna River, upstream from Harrisburg, receive coal-mine drainage. The headwaters of the West 

Branch Susquehanna and Juniata Rivers receive coal-mine drainage 

from the bituminous coal fields in western Pennsylvania. The Nescopeck, Catawissa, Shamokin, Mahanoy, and Manha ntango Creeks 

and Lackawaiina River receive coal-mine drainage from the anthracite coal fields in the northeastern part of the Common wealth.
CHEMICAL CHARACTER OF SUSQUEHANSTA RIVER 

77° 76°

Bll

41'

40'

EXPLANATION

 

Sampling Station

10 10 MILFS

FIGURE 5. Map of the central Susquehanna River basin.

The chemical quality of streams receiving water drained from coal 

mines are strongly influenced by the composition and concentration 

of the coal-mine drainage. As shown by analyses of mine effluents 

from the anthracite coal fields in table 3, coal-mine effluents are low 

in pH (below 5.0) and high in iron (above 1.0 ppm), marganese, 

aluminum, sulfate, and free sulfuric acid content. Accordingly, the 

dissolved-solids contents of the tributaries draining the anthracite 

coal regions range between 100 and 3,000 ppm, depending on the 

.amount and concentration of coal-mine effluents that are pumped or 

seep into the streams in relation to their total flow.
B12 CONTRIBUTIONS TO THE HYDROLOGY OF THE UNITED STATES

TABLE 3. Physical and chemical character of mine drainage from anthracite

coal fields

[Analyses by U.S. Oeol. Survey. Samples collected Tune 28,1959]

Specific conductance (micromhos at 25° C) ______

pH__________-_-_____-_-_

Color___--_ _ _ _____ -

Chemical analyses (parts 

per million): 

Silica (Si02)__ ___ _-.

Aluminum ( Al)_ ______

Iron (Fe) 1 -. - --____

Manganese (Mn) 1 .-.--

Calcium (Ca)___- __-

Magnesium (Mg) _____ 

Sodium (Na)_____ _ _

Potassium (K) ____ __

Bicarbonate (HCOs)--. 

Sulfate (SO4)_________

Chloride (Cl)_.__ ______

Fluoride (F)___ _ _.__

Nitrate (N03)_ _ ____

Residue on evaporation at 180°C-----_-

Calcium, magnesium 

hardness as CaCOs _ 

Total acidity as 

H_S04 -________

Mine A

533

3.60

1

13

.5

9.0

2.9

41

24 

2.0

1.8

0 

214

1.2

.3

.3

332

201 

59

MineB

1,080

2.95

1

16

5.6

9 2

4.9

61

48 

2.0

1.5

0 

427

3.2

.3

.4

671

350 

108

MineO

864

2.95

2

15

1.9

10

2.5

39

31 

1.4

1.2

0

280

.6

.3

.2

446

225 

69

MlneD

1,200

3.00

1

17

10

9.6

5.8

80

56 

1.4

1.5

0

516

1.6

.4

.3

821

430 

132

MineE

400

3.75

2

15

1.1

2.3

21

23 

1.4

1.8

0 

158

.6

.3

. 1

252

147 

15

i At time of sampling.

Chemical analyses of water from the principal tributaries to the 

Susquehanna River above the Harrisburg station are f^ven in table 4. 

The tributaries were usually sampled near their confluence with the 

Susquehanna River. The sampling locations are plotter! on the map of 

the Susquehanna River basin (fig. 5). The bicarbonate-ion concentrations of the eastern tributaries range from 0 to 28 pp'u, and the sulfate-ion concentrations range from 10 to 925 ppm. The concentrations 

of bicarbonate ion in the western tributaries range from 12 to 160 

ppm and of sulfate ion from 8.6 to 65 ppm.

Bar diagrams of sulfate and bicarbonate-ion concentrations (fig. 6) 

show that, with the exception of Wapwallopen Creek, the sufate-ion 

concentration exceeds the bicarbonate-ion concentartion for each of 

the eastern tributaries. The sulfate-ion concentration exceeds the 

bicarbonate-ion concentration in only one of the western tributaries, 

the West Branch Susquehanna River. Coal-mine drainage caused 

this high sulf ate-low bicarbonate relation in these streams.
CHEMICAL CHARACTER OF SUSQUEHANNA RIVER B13

1000

Z

o

^500

CtL

LU 

Q.

oe

<

Q_

o

<

EASTERN TRIBUTARIES

o

LU ^ 

Q_ UJ 

O LU

o o: tn o

o

BICARBONATE 

SULFATE

0

o

O

o

O

O

00

LU

O^^O 200 

o 

100

0

WESTERN TRIBUTARIES

 r-, _

%* LU~ Z?

X LU TV^, LJ f

£g |I a '

c/> <

n

rsrJ 1 H 1 ISSS S

^ LU ^ ^ 2 1 j T^LU i o: ^v* ^

e g^ <LLI ^ 5 Z

N -?= Z ^ W Z»^ * ^o =;a: ujo: rnLu 

^ 10 SLJ 

<" Q?^

CO

O

z 

o 

o

FIGURE 6. Sulfate- and bicarbonate-ion concentrations in the principal tributaries of the

Susquehanna River.
B14 CONTRIBUTIONS TO THE HYDROLOGY OF THE UNITED STATES

TABLE 4. Chemical analyses, in parts per million, at sampling stations in the 

Susquehanna River basin, Pennsylvania

[Analyses by U.S. Geol. Survey]

Stream

Lackawanna River.. ____ ..

Wapwallopen Creek ...........

Nescopeck Creek _______

Fishing Creek.. ................

Catawissa Creek.... ...........

West Branch Susquehanna 

River _____________

Shamokln Creek _ . ...........

Penn Creek ....................

Middle Creek........... __ ...

Mahanoy Creek ________

Mahantango Creek ______

Wlconlsco Creek ...............

Shennan Creek...... ..........

Conodogulnet Creek ...........

Date

8-25-60 

6-23-50 

6-23-50 

10-11-57 10-22-59

8-9-60 

10- 7-59 

10- 8-59 

4-19-60 

6-23-50 

6-23-50 

10-23-59 8- 1-60 

10-21-59 

10-12-57

Bicarbonate 

(HCO,)

0 

16 

0 

20 

0

12

0 

103

56 

0 

6 

28 

126 

99 

160

Sulfate 

(S04)

573 

10 

262 

12 

150

65 

853 

12 

8.6 

925 

62 

102 

43 

16 

27

Hardness as CaCOCalcium, 

magnesium

530 

18 

154 

22

87

72 

700 

86 

50 

709 

108 

128 

136 

97 

136

Non 

carbonat3

530 

5 

154

6 

87

62 

700 

2 

4 

7119 

61 

105 

33 

16 

5

Specific 

conductance (micromhos 

at 25°C)

1,080 

47 

650 

73 

349

189 

1,730 

195 

120 

1,620 

179 

299 

315 

198 

350

PH

3.75 

6.6 

3.90 

6.2 

3.95

6.4 

3.00 

7.4 

8.0 

3.90 

4.9 

6.4 

7.6 

7.1 

7.2

Chemical analyses of water samples from cross-section locations 

on the Susquehanna River above and below Harrisburg are tabulated 

in table 5. These samples were collected during a low discharge 

(14,800 cf s at Harrisburg) so that the variation in chemical character 

of the cross section would be maximized.

The chemical analyses of water samples from cross-section locations 

on the Susquehanna River at Danville and near Duncannon (table 5) 

show the effect of mine drainage from the Lackawanna River and 

the Nescopeck, Catawissa, Shamokin, Mahanoy, Mahantango 

Creeks. The sulf ate-ion concentration increases in a west to east direction. This increase is further evidence of the pattern of higher sulfate-ion concentrations and lower pH's on the east side of the cross 

sections as a result of the coal-mine drainage from the anthracite coal 

fields into the eastern tributaries (fig. 6) of the Susquehanna River. 

The pattern is retained in the east channel stations of the Harrisburg 

cross sections (fig. 3).
CHEMICAL CHARACTER OF SUSQUEHANNA RIVER B15

TABLE 5. Chemical analyses, in parts per million, at cross-section sampling locations on the Susquehanna River in Pennsylvania, collected July 19, 1961

[Analyses by U.S. Geol. Survey]

Station

Danville: 

West side. _________

West center_-______

Center. __ _ ______

East center- _______

East side ___ _____

Duncannon:

Center ___ ________

East center. _______

East side. ___--____

Harrisburg: 

West 1320. ----___-

West 1100.. ___ .

West 600____ _ _

East 1180 __________

East 600 _ _-----._

East 120 ______ _

Columbia: 

West side. _ ___.__-

Center __ __ _ ______

East center. _______

East side _________

Bicarbonate 

(HCOi)

62 

67 

62 

58 

50

36 

29 

58 

65 

20

156 

94 

44 

34 

59 

34

73 

69 

60 

56 

61

Sulfate 

(80*)

69 

82 

85 

90 

91

54 

67 

69 

80 

206

19 

33 

52 

66 

82 

140

50 

52 

66 

82 

93

Hardness as CaCOs

Calcium 

magnesium

120 

132 

136 

134 

128

80 

94 

118 

130 

220

160 

106

84 

88 

124 

168

106 

104 

112 

128 

144

Noncarbonate

69 

76 

85 

87 

87

51 

70

71 

77 

204

32 

29 

48 

60 

76 

140

46 

48 

63 

82 

94

Specific 

conductance (micromhos 

at 25°O)

290 

317 

332 

328 

310

196 

228 

291 

329 

493

313 

241 

201 

217 

302 

399

253 

251

267 

296 

335

PH

7.2 

7.2 

7.2 

7.5

7. 1

7.2

6.7 

7. 1 

7. 1 

6.7

7.9 

7.8 

7.3 

7. 1 

7.1 

6.9

7.3 

7.2 

7.5

7. 2 

7.0

The effect of coal-mine drainage (high sulfate concentrations and 

low pH) from the bituminous coal fields in western Pennsylvania 

on the chemical quality of the Susquehanna River at Harrisburg 

is not so pronounced as is the effect of the anthracite fields on eastern 

tributaries. Neutralization and dilution of streams draining the 

bituminous coal fields by tributaries draining limestone and dolomite regions in south-central Pennsylvania retard the effect of acid 

mine drainage.

The effect of coal-mine drainage on the chemical quality of water 

is more pronounced on the West Branch Susquehanna Biver than 

on the Juniata River (table 4). At the Lewisburg sampling station (fig. 5) on the West Branch Susquehanna River, the concentration of the sulfate ion generally exceeds the bicarbonate ion, but 

at the Newport sampling station on the Juniata River the bicarbonate ion exceeds the sulfate ion (table 4). Durfor and Anderson 

(1963) reported that for the period 1944-52 the average sulfate-ion 

concentration at the Lewisburg station was 50 ppm, although the 

average bicarbonate-ion concentration was 10 ppm. For tbe same
Bll6 CONTRIBUTIONS TO THE HYDROLOGY OF THE UNITED STATES

period, the average sulfate-ion concentration at the, Newport station 

was 41 ppm, though the average bicarbonate-ion concentration was 

72 ppm.

GEOLOGIC INFLUENCES

Both the eastern and the western tributaries of the Susquehanna 

Kiver in the vicinity of Harrisburg are underlain by limestone and 

dolomite formations and by glacial-drift deposits. Each geologic 

environment influences the chemical character of the stream. The 

limestone and dolomite influence the chemical quality because of 

their position in valley bottoms and their soluble nature. The glacialdrift deposits blanket the uplands in northeastern Pennsylvania. 

Many of the streams draining the glaciated part flow over buried 

valleys filled with glacial-outwash deposits. Tlr^e deposits are 

permeable and are hydraulically connected to underlying formations.

With few exceptions, calcium-bicarbonate type of water predominates in the tributaries draining into the west side of the Susquehanna River. These tributaries drain regions urderlain by limestone and dolomite formations or by glacial-drift deposits. Hence, 

streams draining these regions are generally alkaline (pH 6.0-8.5) 

and high in calcium, magnesium, and bicarbonate-ion concentration, 

in relation to other constituents. Concentrations of calcium, magnesium, and bicarbonate ions and pH are lower in streams draining 

the glacial-drift areas in the northern part of the basin than in the 

limestone terranes. Chemical analyses of several western tributaries are presented in table 4 to show chemical quality of the streams 

draining into the west side of the Susquehanna Hirer above Harrisburg. Figure 6 is a graphical illustration of the sulfate and bicarbonate-ion concentrations for the various tributaries named in 

table 4.

The bicarbonate-ion concentration at the Harrisburg station W. 1320 

is considerably higher (156 ppm) than the concentrations at the west 

side stations at Danville (62 ppm) or near Duncannon (36 ppm). The 

Duncannon station is just above the confluence of the Juniata River. 

The higher bicarbonate-ion concentrations at station W. 1320 may be 

due to the high concentration of bicarbonate in the vater of the Juniata River and the Conodoguinet Creek (fig. 4).

Most of the tributaries that drain into the east side of the river 

receive coal-mine drainage, and geologic influences do not predominate. Wapwallopen Creek, an exception, drains an area of glacial 

drift overlying sandstone and shale but does not receive coal-mine 

drainage. It is low in dissolved solids and generally is higher in 

bicarbonate-ion concentration than in sulfate-ion concentration 

(fig. 6).
CHEMICAL CHARACTER OF SUSQUEHANNA RIVER B17

CONCLUSIONS

The chemical quality of cross-section samples collected near the 

west bank at Harrisburg closely resembles the water of the Juniata 

Eiver and Conodoguinet Creek, which drain the limestone famines 

to the west of the Susquehanna Eiver. These streams tend to entrain 

along the west bank of the Susquehanna River and to carry water 

high in pH and in calcium, magnesium, and bicarbonate-ion 

concentrations.

Water in the center of the Harrisburg station generally resembles 

the chemical character of the West Branch Susquehanna River, as 

its dissolved-solids content is low in relation to other sections of the 

river, and its sulfate-ion concentration generally exceeds the bicarbonate-ion concentration.

Water sampled near the east or Harrisburg bank shows the ir fluence 

of coal-mine drainage. River water from east channel station E. 120 

is high in sulfate-ion concentration (36-301 ppm) and ranges in pH 

from slightly acid to slightly alkaline (5.7-7.5).

Although the long distance involved, the many islands and bridge 

piers, and the rocky streambed favor mixing of the Susquehanna 

River flow, the chemical composition of water at the Harrisbur? cross 

section indicates that the principal tributaries above Harrisburg do 

not intermix sufficiently to lose their identity before reaching Harrisburg. In fact, the cross-section variations in chemical composition 

of the water at the Harrisburg station are retained at Columbia, several miles downstream from the Harrisburg station. This lack of 

lateral mixing probably is due to the very small depth-width ratio 

and also to the extreme width of the river. The river at median flow 

at the Harrisburg sampling station ranges between 3.9 and 9.3 feet 

deep and is approximately 3,000 feet or slightly more than half a mile 

wide.

REFERENCES

Beamer, N. H., 1953, Chemical character of surface water in Pennsylvania,

1949-51: Pennsylvania Dept. Commerce, State Planning Board. 

Durfor, C. N., and Anderson, P. W., (1963), Chemical quality of surface waters

in Pennsylvania: U.S. Geol. Survey Water-Supply Paper 1619-W, W1-W50. 

Rainwater, F. H., and Thatcher, L. L., 1960, Methods for collection and analysis

of water samples: U.S. Geol. Survey Water Supply Paper 1454, 301 p. 

White, W. F., Jr., 1947, Industrial utility of water in Pennsylvania, Chemical

character of surface water, 1944-46: Pennsylvania Dept. Commerce, State

Planning Board.

 1949, Chemical quality of industrial surface waters of Pennsylvania: 

Paper prepared for presentation at the Tenth Annual Water Conference of 

the Engineers' Society of Western Pennsylvania.

 1951, Chemical character of surface water in Pennsylvania, 1946^9:

Pennsylvania Dept. Commerce, State Planning Board.

U.S. GOVERNMENT PRINTING OFFICE: IS'3