so212 ~101 

REPORT DOCUMENTATION II. 3. Recipient's Accession No. REPORT NO. 

PAGE I 

4. Title and Subtitle 5. Report Date 

Investigation of Acidity and Other Water-Quality July 1980 

Characteristics of Upper Oyster Creek, Ocean County, New Jersey r-----~----------------------~ 6. 

7.Author
 Thomas V. Fusiilo, James C. Schornick, Jr., Harry E. 8. Performing Organization Rept. No. 

Koester, and Douglas A. Harriman USGS/WRI/NTIS 80-10 

9. Performing Organization Name and Address 10. Project/Task/Work Unit No. 

U.S. Geological Survey, Water Resources Division 

Room 430 Federal Building 11. Contract(C) or Grant(G) No. 

402 East State Street (C) 

Trenton, New Jersey 08607 

(G) 

12. Sponsoring Organization Name and Address 13. Type of Report & Period Covered 

U.S. Geological Survey, Water Resources Division Final Room 430 Federal Building 

• 402 East State Street 14. 

Trenton, New Jersey 08607 

15. Supplementary Notes 

Prepared in cooperation with the New Jersey Department of Environmental Protection, 

Division of Fish, Game, and Shell Fisheries 

16. Abstract (Limit: 200 words) Water-quai]. ty Ga Ea-·coileC:fed in .TFie ___ upper._bys ter Creek .drain-age bas in 

indicate that the stream has excellent water quality except for a persistently low pH. 

The mean concentrations of the major inorganic ions were all less than 6.0 mg/L. Mean 

concentrations of total nitrogen and total phosphorus were 0.15 mg/L and 0.01 mg/L, 

respectively. Dissolved oxygen averaged 8.7 mg/L and 81 percent saturation. 

Low pH levels are typical of streams draining cedar swamps. In Oyster Creek, the pH 

tended to decrease downstream due to chemical and biological processes. The pH levels 

in swamps were one-half unit or more lower than the pH levels in the adjacent stream. 

Sharp declines in stream pH were noted during runoff periods as the result of the 

mixing of poorly-buffered stream water with more highly acidic water from surrounding 

swamp areas. 

The quality of ground water within the study area was similar to the quality of 

streamflow, except for higher iron and ammonia-nitrogen concentrations and a higher pH 

range of 4.9-6.5. Precipitation represented a major source of many chemical 

constituents in the ground- and surface-waters of Oyster Creek basin. 

~------------------------------------------------------------------------------------------------------, 

17. Document Analysis a. Descriptors 

i~"Water quality, i~"acidic water, 'i'I"New Jerse-y, hydt'ogen ion concentration, surface 

water, ground water, precipitation (atmospheric), swamps. 

b. ldentifiers/Open·Ended Terms 

Oyster Creek, Ocean County, Pinelands 

c. COSATI Field/Group 

18. Availability Statement 19. Security Class (This Report) 21. No. of Pages 

UNCLASSIFIED 30 

No restriction on distribution ~-------------------------~--------------------

20. Security Class (This Page) 22. Price 

UNCLASSIFIED 

OPTIONAL FORM 272 (4-77) (See ANSI-Z39.18) See Instructions on Reverse (Formerly NTIS-35) 

Department of Commerce 
INVESTIGATION OF ACIDITY AND OTHER WATER-QUALITY 

CHARACTERISTICS OF UPPER OYSTER CREEK, 

OCEAN COUNTY, NEW JERSEY 

By Thomas V. Fusillo, James C. Schornick, Jr., 

Harry E. Koester, and Douglas A. Harriman 

U.S. GEOLOGICAL SURVEY 

Water-Resources Investigations 80-10 

This document was prepared by the U.S. Geological Survey 

under a contract with the New Jersey Department of 

Environmental Protection, Division of Fish, Game, and Shell 

Fisheries. This project has been financed in part with funds 

from the Federal Aid in Fish Restoration Act (P.L.81-681) 

administered by the U.S. Fish and Wildlife Service, 

Department of the Interior. 

July 1980 
CONTENTS 

Page 

Conversion factors................................ v 

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

Introduction...................................... 2 

Acknowledgments.............................. 2 

Purpose and scope............................ 2 

Description of the project area................... 3 

Geology and soils............................ 3 

Climate .................................... ·-· 6 

Hydrology.................................... 6 

Land use..................................... 6 

Data Collection................................... 8 

Results........................................... 9 

Streamflow................................... 9 

Surface-water quality........................ 13 

Ground-water quality......................... 16 

Precipitation quality........................ 18 

Discussion........................................ 20 

Acidity and pH in Oyster Creek............... 20 

Effects of acidity on trout.................. 25 

S u mm a r y • . . • . • . • . . • . . • • • . . . • . . . . . . • . . . . . . • . . • . . • . . . 2 7 

Selected references............................... 29 

ILLUSTRATIONS 

Figure 1. Map showing data collection sites in 

Oyster Creek study area............. 4 

2. Map of soil types within upper Oyster 

Creek basin......................... 5 

3. Idealized cross section showing groundwater flow patterns in the Pinelands 

region............................... 7 

4. Discharge hydrographs for site A-1, 

Oyster Creek near Brookville, 

New Jersey; water years 1975-77. .... 10 

5 . Flow-duration curve for site A- 1 ; 

water years 1966-77................. 11 

iii 
ILLUSTRATIONS--Continued 

Page 

6. Low-flow frequency curves for site A-1; 

water years 1966-77................. 12 

1. Profile of pH values along the main 

stem of Oyster Creek; i975-77....... 21 

8. Graph showing pH frequency curves for 

site A-1 and adjacent swamp 

sampling site; 1974-77.............. 23 

9. Graph showing daily mean discharge and 

daily minimum pH at site A-1; April 

through September 1975. ............. 24 

10. Graphs showing hourly gage height and 

pH at site A-1 during four storms; 

Apr i 1 1 9 7 5 to Dec ember 1 9 7 6 . . . . . . . . . 2 6 

TABLES 

Table 1. Mean, maximum, and minimum values of 

water-quality characteristics for 

site A-1, Oyster Creek near 

Brookville, New Jersey, water 

years 1966-77..... .. ... ...... .. .. ... 14 

2~ Chemical analyses of Oyster Creek and 

tributaries; April 13, 1978, and 

May 24, 1978........................ 15 

3. Chemical analyses of ground water in the 

vicinity of Oyster Creek............ 17 

4. Chemical analyses of precipitation at 

the Oyster Creek rain gage near 

Brookville, New Jersey.............. 19 

iv 
CONVERSION FACTORS 

Factors for converting inch-pound Units to International 

System (SI) Units 

Multiply inch-pound units To obtain SI units 

inch (in) 25.4 millimeter (mm) 

foot (ft) 0. 3 04 8 meter ( m) 

mile ( mi) 1 . 609 k il om eter ( km) 

acre 4047 square meter ( m2 ) 

square mile ( mi 2 ) 2.59 square kilometer 

( km2 ) 

cubic foot per second 

( ft 3 /s) 

0. 02832 cubic meter per 

second (m 3 /s) 

pound (lb) 0. 45 4 kilogram (kg) 

v 
ABSTRACT 

Water-quality data collected in the upper Oyster Creek 

drainage basin indicate that the stream has excellent water 

quality except for a persistently low pH (median 4.5). 

The mean concentrations of the inorganic ions were all less 

than 6.0 milligrams per liter. Mean concentrations of total 

nitrogen and total phosphorus were 0.15 and 0.01 milligrams per 

liter, respectively. Dissolved oxygen averaged 8.7 milligrams per 

liter and 81 percent saturation. 

Low pH is typical of streams draining cedar swamps. Within 

the study area, pH tended to decrease downstream due to chemical 

and biological processes. The pH in swampy areas was half a unit 

or more below the pH in the adjacent stream. 

Sharp declines'in stream pH were noted during runoff as the 

result of the mixing of poorly buffered stream water with more 

highly acidic water from surrounding swamp areas. These pH 

declines severely hinder brook trout survival due to the toxic 

effect of highly acidic water. 

The quality of ground water was similar to the quality of 

streamflow, except for higher iron and ammonia-nitrogen 

concentrations and a pH range of 4.9 to 6.5. The highest 

concentrations of most chemical constituents were found in the 

ground water within the organic muck beneath swamp areas. 

The quality of precipitation on the area was also similar to 

the quality of streamflow. The pH of precipitation ranged from 

4.2 to 1.0. Precipitation represents a major source of many 

chemical constituents in the water of the Oyster Creek basin. 
INTRODUCTION 

The rapid increase in recreational fishing in New Jersey and 

the growing pressure on freshwater fisheries make it desirable to 

expand current trout-stocking programs of the streams in the outer 

Coastal Plain of New Jersey. These streams appear to be well 

suited to supporting trout; they have cool temperatures, 

sufficient dissolved oxygen, and are relatively free of pollution. 

One unfavorable characteristic of these streams, however, is a 

very low pH, even for trout waters. The pH of most coastal-plain 

streams averages between 4.0 and 5.0 (Rhodehamel, 1970). Rapid 

drops in pH to below 4.0 have been observed during runoff; under 

these conditions trout survival is affected. 

Preliminary investigations during the 1950's (Pyle, 1957) 

involved survival experiments with brook trout, Salvelinus 

fontinalis, brown trout, Salmo trutta, and rainbow trout, Salmo 

irrideus, in various streams of the outer coastal plain of New 

Jersey. These experiments indicated that brook trout is the most 

acid-tolerant species, capable of surviving in streams with pH as 

low as 4.3. Brown trout and rainbow trout did not survive in 

streams with pH below 5.0 and 5.9, respectively, and were 

considered unsuitable for stocking in the more acidic streams. As 

the pH of most coastal-plain streams falls below 4.3 for at least 

brief periods during the year, even brook trout may not survive. 

Brook trout were stocked experimentally in Oyster Creek, 

Ocean County, during the 1950's and 1960's. The creek provides 

good trout habitat,~except for its low pH. The flow is fairly 

uniform throughout the year, with ground-water inflow maintaining 

high water levels even during the summer. The water temperature 

in the creek is moderated by ground water, causing cooler temperatures than expected during the summer and warmer temperatures 

during the winter. The dissolved oxygen content of the water 

rarely falls below a concentration of 6.0 mg/L; and the overall 

water quality is excellent, with very low concentrations of 

dissolved and suspended materials. Thus, the low pH seems to be 

the major barrier to a successful trout-stocking program. 

Acknowledgments 

The authors are grateful for the cooperation received from 

the residents of Brookville, New Jersey. They also thank 

Mr. Clifford Oakley of Manahawkin, New Jersey, for permitting work 

to be done on his property. 

Purpose and Scope 

The U.S. Geological Survey, in cooperation with the New 

Jersey Department of Environmental Protection, Division of Fish, 

Game, and Shell Fisheries, made a study from 1968 to 1978 to 

assess the chemical quality of upper Oyster Creek. Emphasis was 

placed on monitoring pH and the chemical constituents that affect 

the pH of natural waters. This report includes streamflow and 

2 
water-quality data collected at the gaging station, Oyster Creek 

near Brookville, between 1965 and 1977 as part of the statewide 

stream-monitoring network, in addition to data collected specifically for this study. This report will present the data to aid in 

developing management techniques for brook trout in acidic streams 

and lakes. 

DESCRIPTION OF THE PROJECT AREA 

Oyster Creek is located in the Pinelands along the eastcentral part of New Jersey's outer Atlantic Coastal Plain in 

so u t h e r n Oc e an Co un t y . It s d r a in age a r e a i s 1 2 . 9 m i 2 at the m o u t h 

of Barnegat Bay. This study includes only a 7.43 square-mile area 

in the upper part of the basin above the U.S. Geological Survey 

surface-water gaging station No. 01409095, Oyster Creek near 

Brookville. The location of the study area is shown in figure 1. 

Oyster Creek flows over the Cohansey Sand for most of its 

length. Most soils in the watershed are poor, thin, and deficient 

in fertility due to the rapid leaching of nutrients. The creek 

flows through many bogs, ponds, and swamps. The basin contains 

several cranberry bogs, although cranberry farming has nearly 

ceased on Oyster Creek because of interference caused by 

recreational activities. 

Geology and Soils 

The Cohansey Sand which underlies most of the outer coastal 

plain, is approximately 150ft deep in the area of Oyster Creek. 

The contact between the Cohansey Sand and the underlying Kirkwood 

Formation dips to the south-southeast at approximately 10 ft/mi 

(Rhodehamel, 1973). The Cohansey Sand is of Miocene age and is 

characteristically a yellow-brown fine to very coarse quartz sand 

that is locally cemented with iron oxide. White, dark-gray, and 

red kaolinitic clay deposits are interbedded with the sand beds 

(Anderson and Appel, 1969). 

The soil types that overlie the Cohansey Sand within the 

Oyster Creek basin are largely sands and sandy loams, averaging 10 

ft in depth. They are low to moderate in fertility and available 

water capacity and have rapid permeability, except where interbedded with clay. These soils are typified by strongly acidic 

soil reactions. The pH of the soil-water solution in the upper 

soil profile ranges from 3.6 to 5.5. The distribution of soil 

types is shown in figure 2. 

The main stream channel of Oyster Creek and the surrounding 

swampy areas are underlain by the Manahawkin muck, a soil composed 

of finely divided organic material which is extremely acidic. 

Most of the tributaries to the main channel lie on the Atsion 

sand, a very sandy soil containing moderate to high amounts of 

organic matter. The Atsion sand has a seasonally high water table 

which is at the surface during wet seasons but may drop 2 to 3 ft 

during the summer. The Berryland sand forms the flood plains of 

3 
S as in Sou n da ry 

A Gaging Station 

'Y Surface-Water Quality Sampling Site 

e Observation Well 

Figure 1.--Map ahowing data collection sites in Oyster Creek 

study area. 

+:::-
N 

~ 

j 

\ 

EXPLANATION 

0 1M i Ia , Y2 []] 1 ' I I Impoundments I J 

0 Y2 1 Kilometer [8 Aura sandy loam [IE] lakehurst sand 

SCALE ~ Atsion sand [GJ lakewood sand 

Base and I 0 i I classifications ~ Berryland sand ~ Manahawkin muck 

adapted I rom 

u.s. So i I Conservation Service ~ Downer sand/loam ~ Pocomoke sandy loam 

Interim So i I Survey 

Ocean County 1:20,000, 1977 Evesboro sand [EJ Sassafras sandy loam 

[B!J Hammonton sandy loam ~ Woodmansie sand 

~ Keyport sandy loam 

Figure 2.-- l1ap of soil types within upper Oyster Creek basin. 

5 
Oyster Creek, with a mucky surface layer and a sandy subsurface. 

Berryland soils also contain moderate to high amounts of organic 

material and may be frequently flooded. At higher elevations in 

the drainage basin are the Aura sandy loam, Downer sandy loam, 

Woodmansie sand, Lakehurst sand and Lakewood sand. These are all 

well-drained soils with a low productivity, although they support 

growth of mixed woodlands, including pitch pine and scrub, white, 

and black oak. 

Climate 

The Oyster Creek basin experiences a temperate, mostly 

continental, climate. The mean annual air temperature is 54° F 

(12° C), with a range in mean monthly temperature from 34° F (1° 

C ) in J a n u a r y to 7 5 o F ( 2 4 o C ) in J u 1 y . Oc e an i c a i r rna s s e s 

intrude the land area in late summer, making July and August the 

wettest, warmest, and most humid months of the year. The ave~ge 

annual rainfall for the area is 45 inches, with the highest 

monthly averages in July and August, at 4.4 inches and 4.7 inches, 

respectively. 

Hydrology 

The hydrology of the Oyster Creek basin and most of the 

Pinelands region is strongly influenced by ground-water flow 

patterns. The sandy soils permit rapid infiltration' of rainfall 

into the aquifer, and ground water constitutes an average of 89 

percent of the total annual stream discharge within the Pinelands 

( Rhod ehamel, 1970). 

Oyster Creek is unique in having surface-water discharge 

greater than the precipitation the surface-water drainage basin 

receives. The mean annual discharge of Oyster Creek at the 

Brookville gaging station at site A-1 during the period 1966 

through 1977 was 50.8 inches, while the mean annual precipitation 

over the same period was only 45.2 inches. Low-flow analysis 

( G i 11 e s pie , per son a 1 com m u n . , 1 9 7 9 ) s h o w s that wh i 1 e Oy s t e r Cr e e k 

has excessive surface runoff, the nearby Oswego River and North 

Branch Forked River have much lower rates of surface runoff. 

Rhodehamel (1970) has described a regional flow system in the 

Pinelands in which recharge enters a shallow local flow system in 

the upland areas of the Cohansey Sand, bypasses some local 

streams, and discharges into more distant streams in the 

peripheral areas at lower altitudes. Oyster Creek, being a lowlying basin, may receive ground-water inflow from the Oswego River 

and/or North Branch Forked River basins. Figure 3 represents an 

idealized cross section showing ground-water flow patterns in the 

Pinelands region. 

Land Use 

The Oyster Creek study area lies within Ocean, Lacey, and 

Union Townships in Ocean County and is almost entirely 

undeveloped. Two county highways, routes 532 and 534, and several 

6 
ctl ctl Upland Area (1,) 

(1,) :( :( 

~ (1,) 

.c. 

c. 

.... 

(1,) 

Q.. 

NW SE 

-----.] 

(From Rhodehamel, 1970) 

Figure 3.-- Idealized cross section showing ground-water flow patterns 

in the Pinelands region. 

~ 
other improved roads pass through the basin. Unimproved roads and 

trails crisscross through the forested upland areas of the watershed. There is a small residential area consisting of several 

dozen homes at Brookville in the upper reach of the basin. 

Several cranberry bogs within the study are no longer commercially 

productive. The Brookville Boy Scout Reservation is located on 

one of the bogs and a private campground on another. Both utilize 

the bogs for swimming, boating, and fishing. 

In the northwest part of the Oyster Creek basin is a sanitary 

landfill of approximately 40 acres. A sand and gravel pit is 

located along the drainage divide between Oyster and Mill Creeks 

in the southwest corner of the basin. The locations of the 

landfill and the sand pit are shown in figure 2. 

Most of the Oyster Creek watershed is wooded, with white 

cedar predominating in the low-lying swampy areas. Sphagnum moss, 

swamp magnolia, mountain laurel, and various berries are also 

common in poorly drained regions. The more well-drained areas of 

the basin are forested with white oak and pitch pine, with a 

fairly dense undergrowth of brush. 

DATA COLLECTION 

The initial water-quality data collection began in 1968, with 

the installation of a strip-chart pH recorder at site A-1, the 

stream-gaging station Oyster Creek near Brookville, N.J. (See 

figure 1.) The strip-chart pH recorder was removed in November 

1974 after numerous malfunctions and replaced in January 1975 by a 

four-parameter water-quality monitor (monitoring pH, specific 

conductance, temperature, and dissolved oxygen). After the 

collection of water-quality records, the monitor was removed in 

April 1977. 

Weekly field visits were begun in January 1974 to complement 

the automatic data collection with the collection of pH data at 

site A-1 and an adjacent swamp, shown in figure 1. In November 

1975, the field data collection was expanded to include additional 

sampling sites on the main stem of Oyster Creek and its major 

tributaries. Temperature and pH were measured in the field at six 

sites on the main channel and sites on seven tributary streams. 

Additional water-quality data were collected at these surfacewater sites during two intense sampling periods, one on April 13, 

1978, during baseflow conditions and the second on May 25, 1978, 

after a 3-inch rainfall. Specific conductance, pH, temperature, 

and dissolved oxygen were measured in the field. Samples were 

collected for the analysis of dissolved solids, total hardness, 

ferrous and total iron, sulfate, chloride, and total nitrogen. 

Continuous streamflow records have been collected at the U.S. 

Geological Survey gaging station, Oyster Creek near Brookville, 

New Jersey (site A-1), since July 1965. Water samples for 

chemical analyses were collected periodically at the site from 

September 1965 to September 1977. 

8 
Ground-water levels in the Oyster Creek basin were monitored 

continuously at two observation wells. Well 1 was bored into the 

swamp deposits near the stream channel to a depth of 4 ft. Well 2 

was bored through the swamp deposits adjacent to well 1 into the 

top of the underlying Cohansey Sand to a depth of 14 ft below the 

land surface. These wells were operated from August 1973 to June 

1976. Water samples for chemical analysis were collected from 

the s e we 11 s on Dec em be r 5 , 1 9 7 4 , and Nov em be r 5 , 1 9 7 5 . One o f t wo 

local Waretown observation wells, which had been last sampled in 

1962, was resampled in January 1977. 

Monthly precipitation data for the period January 1966 to 

December 1977 were obtained from annual climatic data summaries of 

the National Oceanic and Atmospheric Administration (1966-77). 

Monthly precipitation at Oyster Creek was estimated by averaging 

the precipitation data for the official gages at Chatsworth, Toms 

R i v e r , and Tu c k e r ton . In Sept ember 1 9 7 6 , a record in g r a in g age 

was installed in the watershed and operated until April 1977. 

RESULTS 

Streamflow 

The streamflow in Oyster Creek is moderated throughout the 

year by ground-water inflow, resulting in a steady baseflow and 

infrequent serious flooding. The discharge hydrographs shown in 

figure 4 for water years 1975, 1976, and 1977 are all relatively 

flat, with few sharp peaks. The permeable, sandy soils within the 

basin promote rapid infiltration of rainfall into the ground-water 

system, reducing surface runoff. The rate of runoff is further 

reduced by water storage in the swamps. The mean discharge for 

the period of streamflow record at site A-1 is 27.8 ft 3 ls, with 

maximum and minimum discharges of 232 and 12 ft 3 1s. 

The flow-duration curve for site A-1, which shows the 

percentage of time that discharges were equalled or exceeded 

during the period of streamflow record, is presented in figure 5. 

The flat slope of the curve shows the influence of surface-water 

and ground-water storage on the stream hydrology (Searcy, 1959). 

Low-flow characteristics of a stream are commonly used to 

evaluate the adequacy of streamflow for maintenance of suitable 

conditions for fish (Riggs, 1972), since stress periods often 

occur during low-flow conditions. The low-flow frequency curves 

for Oyster Creek are shown in figure 6. They give the recurrence 

interval and probability of low-flow periods of duration from 1 to 

30 consecutive days. These curves show that the 7-day, 10-year 

low flow, i.e., the average minimum flow for 7 consecutive days 

that is expected to occur on the average of 1 year in 10, is 16 

f t 3 I s o r 2 . 1 5 ( f t 3 I s ) I m i 2 • Th i s l e v e 1 o f d i s c h a r g e d u r i n g 1 o w -

flow periods is sufficient for maintaining acceptable stream 

conditions for fish. 

9 
WATER YEAR 1975 

tw 

w 

u. 

(.) 

0 CD z :::> 

(.) 0 

(.) 

z w 

Cf) 

w 

~ a: 

a: w 

< 0. 

J: 

(.) 

Cf) 

c 

10 

tw 

w 

u. 

(.) c 

CD z 

:::> 0 

(.) (.) 

z w 

Cf) 

w a: 

w ~ 

a: 0. 

<( 

J: 

(.) 

Cf) 

0 

WATER YEAR 1977 

tw 

w 

u. 

(.) 

CD c 

:::>z 

oo 

zo _w 

Cf) 

w 

R 

a: ~ w 

a: 0. 

< 

J: 

(.) 

Cf) 

0 

Figure 4.--Discharge hydrographs for site A-1, Oyster Creek near 

Brookvi1 , New Jersey; water years 1975-1977. 

10 
,..0 

• 

Oz 

... 0 

wo <!>w 

O::(f) 

::z::w 

<(a:: 

OQ.. (f) 

o.-

w 

>-w 

_JlJ... 

<(0 o_ 

en 

Z::::> 

<(o 

wz ~a- ~- • 

10~~~--~~--~--~----~--~~~--~~--~--~--~----~-L---~~~ 

0.1 0.2 0.5 I 2 5 10 20 50 90 95 98 99 99.5 99.9 

PERCENT OF TIME DISCHARGE WAS EQUALLED OR EXCEEDED 

Figure 5.-- Flow-duration curve for site A-1; water years 1966-1977. 

~ 

~ 
RECURRENCE INTERVAL, IN YEARS 

301.01 1.2 1.5 2 5 10 20 50 

0 

z 

0 

w 

(.) 

C/) 

ffi 25 

a.. 

..... 

w 

w 

u.. 

m 

(.) 20 

:::> 

(.) 

z - - - - -- w 

> 

w 

(.!) 

a: r ~~~~ :::::::-----:=: 14 15 ~ C/) 

<t 7 w~ I 

(.) 3(/)o 

C/) ,a 

0 10- 0 I I I I I I I I 

0.93 0.95 0.9' 0.8 0.5 0.2 0.1 0.04 0.02 

PROBABILITY 

Figure 6.-- Low-flow frequency curves for site A-1; water years 1966-1977. 

f--1 

{'--.) 
Surface-Water Quality 

.. The w a t e r in Oy s t e r Cr e e k i s typic a 11 y 1 o w in · p H , n u t r i en t s , 

and dissolved solids. Below the reservoir at site A-3, sodium and 

calcium are the most abundant cations and chloride is the most 

abundant anion. Above the reservoir, sulfate content increases, 

making sulfate and chloride the most abundant anions. Table 1 

lists the mean, maximum, and minimum values of the chemical, 

physical, and biological characteristics monitored periodically at 

site A-1 from 1966 to 1977. 

Dissolved solids concentration ranged from 18 to 42 mg/L with 

a mean of 28 mg/L, and specific conductance ranged from 31 to 61 

wmhos/cm (micromhos per centimeter at 25° C), with a mean of 41 

wmhos/cm. The mean concentrations of the major cations, including 

calcium, sodium, magnesium, and potassium, were all 3.0 mg/L or 

less, and the two major anions, sulfate and chloride, had mean 

concentrations of 4.7 and 5.6 mg/L, respectively. These concentrations are low compared with other values reported for the 

Pinelands region (Rhodehamel, 1970, p. 20). 

Nutrient concentrations are also very low in Oyster Creek. 

Total nitrogen concentrations ranged from 0.02 to 0.36 mg/L, with 

a mean of 0.15 mg/L and nitrate-nitrogen averaged 0.03 mg/L. The 

mean concentration of total phosphorus was 0.01 mg/L, with 9 of 

the 28 samples recording 0.00 mg/L. 

Dissolved oxygen levels were high in Oyster Creek, ranging 

from 70 to 94 percent of saturation, with a mean concentration of 

8.7 mg/L. The ranges of pH from 3.9 to 5.8, dissolved aluminum 

from 0.08 mg/L to 0.5 mg/L, and dissolved iron from 0 to 0.37 mg/L 

are characteristic of surface water in the Pinelands (Rhodehamel, 

1970). The levels of color, ranging from 2 to 85 units, and total 

organic carbon, ranging from 1 to 29 mg/L, are caused by humic 

acid and other organic acids and are also typical of streams in 

the region. The concentrations of fecal coliform and fecal 

streptococci bacteria, which indicate fecal contamination and the 

possible presence of pathogens, were generally low. Mean fecal 

coliform and fecal streptococci bacteria densities were 8 and 29 

colonies/100 ml, respectively. 

The mean concentrations of bicarbonate, 0.8 mg/L, and 

alkalinity, 0.5 mg/L, illustrate the low-buffering capacity of the 

water in Oyster Creek. This low-buffering capacity allows large 

and swift changes in pH after the addition of small amounts of 

acidic material. 

The uniformity of water quality in Oyster Creek over the 

years is shown by the narrow range between the maximum and minimum 

values of most constituents. The quality of water along the main 

stem of Oyster Creek is indicated by the results of chemical 

analyses from sampling sites throughout the basin listed in table 

2. The values of several constituents tended to be slightly 

higher in the upstream reaches of the main stem (sites A-10, A-15, 

13 
Table 1.--Mean, maximum, and m1n1mum values of water-quality 

characteristics for site A-1, Oyster Creek near Brookville, 

New Jersey, water years 1966-77. 

[Results in milligrams per liter, except as noted. Numbers 

in parentheses indicate the number of analyses.] 

Mean Maximum Minimum 

Temperature, o C (133) 

Specific conductance, 

12.6 27.0 1 . 0 

llmhos/cm (51) 

Co lor , un its ( 2 7 ) 

pH, units (75) 

41 

16 

4. 5 * 

6 1 

85 

5.8 

3 1 

2.0 

3.9 

Total hardness (42) 6.0 29 3.0 

Bicarbonate (34) 0.8 5.0 0 

Alkalinity ( 3 4) 0.5 4. 0 0.0 

Acidity (as CaC0 3 ) (10) 1 7 40 0 

Silica (13) 5.5 7.0 3.3 

Calcium (42) 1. 2 3.0 0.5 

Magnesium (42) 0.6 1 • 3 0.2 

Sod i urn ( 37) 3. 0 4.5 1 • 9 

Potassium (37) 0.5 2.0 0.2 

Sulfate (47) 4.7 8.8 2. 1 

Chloride ( 43) 5.6 8.6 3-7 

Total nitrogen (22) 0. 15 0.36 0.02 

Nitrate nitrogen (3~) 0.03 0.25 0. 00 

Organ i c n it r o g en ( 2 0 ) 0. 12 0.33 0.00 

Total phosphorus (28) 0.01 0.05 0. 00 

Aluminum (6) .23 .50 .08 

Dissolved iron (8) . 17 . 37 0 

Dissolved manganese (9) .02 • 1 0 0 

Diss. solids [Residue@ 180°C] (38) 28 42 18 

Dissolved oxygen (41) 8.7 12 6.6 

Oxygen saturation, percent 81 94 70 

Total organic carbon (51) 6.2 29 1 • 0 

Fecal coliforms, 

colonies/100 ml (33) 8** 920 0 

Fecal streptococci 

colonies/100 ml (21) 29** 360 0 

*Median 

**Logarithmic means 

14 
Table 2. --Chemical analyses of Oyster Creek and tributaries; April 13, 1978, and May 24, 1978 

.. [Results in milligrams per liter, except as noted.] 

Specific Field Dissolved Dissolved Total Ferrous Total Total 

Discharge Temperature conductance pH oxygen solids hardness iron iron Sulfate Chloride nitrogen 

Site (ft 3 /s) ( o C) (wnho/cm) (units) 

April 13, 1978 

A-1 33 14.0 45 4.4 8.9 31 7 -·- 0.47 2.8 7.6 o. 35 

A-2 E 20 15.0 46 4.4 9.6 34 7 -- .57 3.0 7.6 .25 

A-10 E 7 17.0 59 4.4 9.9 43 9 -·- .65 7.5 8.4 . 15 

A-15 E 3 13.0 60 4.4 10.0 42 11 -·- .48 7.2 9. 1 .10 

A-20 E 1 12.5 53 4.6 10.3 40 10 -- .74 7.6 7.6 . 15 

B-1 E 4 12.5 39 4.4 9.2 25 5 -·- .47 3. 1 6. 1 .04 

C-1 E 0.01 15.5 67 4. 1 10.3 42 10 -·- .go 6.7 7.6 .85 

D-1 E 1. 5 11.0 65 4.2 6.2 42 9 -- .48 7.0 g. 1 . 18 

E-1 E 1. 0 11.0 53 4.3 g.6 38 8 -- .29 6.0 4.6 .25 

H-1 E 0.2 15.0 60 4.2 10.2 39 9 --· .55 7.5 6.8 .20 

May 24, 1978 

A-1 52* 14.5 47 4.2 7-3 -- -- 0. 13 . 1g 

A-2 65.4* 16.0 45 4.3 g. 1 -- -- .08 .22 

A-10 1. 8** 18.0 54 4.3 8.6 -- -- . 10 .48 

A-20 -- 16.5 50 4.5 8.3 -- -- .14 . 18 

B-1 E 12 15.5 57 4.0 8.6 -- -- . 11 . 18 

C-1 -- 15.0 55 4.1 8.4 -- -- . 11 .16 

E-1 -- 14.0 62 4.0 7.8 -- -- .05 .og 

F-1 E 0.5 15.0 85 3.g 7.0 -- -- .33 .56 

H-1 -- 18.5 66 4.3 7.0 -- -- .34 .58 

* - Samples taken during rapidly rising stage ** -Sluice gate closed, lake filling 

E - Estimated discharge 

1-' 

tn 
and A-20) than in the lower reaches (sites A-2 and A-1). 

The results from the April 13, 1978, sampling show that 

between sites A-20 and A-1 sulfate decreased from 7.6 to 2.8 mg/L, 

total iron decreased from 0.74 to 0.47 mg/L, dissolved solids 

decreased from 40 to 31 mg/L, dissolved oxygen decreased from 10.3 

mg/L to 8.9 mg/L, and specific conductance decreased from 53 to 45 

wmhos/cm. The only constituent which increased in the downstream 

direction was total nitrogen, which increased from 0.15 mg/L at 

A-20 to 0.25 mg/L at A-2 and to 0.35 mg/L at A-1. 

The most significant downstream decrease in concentration was 

that of sulfate. Above the reservoir, at sites A-10, A-15 and 

A-20, sulfate was measured at between 7.2 and 7.6 mg/L. Below the 

reservoir, at sites A-1 and A-2, sulfate was measured at 2e8 and 

3.0 mg/L, respectively. Sulfate reduction by bacteria in the 

organic muds at the bottom of the reservoir was probably 

responsible for the observed decrease in sulfate below the 

reservoir. 

Concentrations of water-quality parameters were more variable 

in the tributaries to Oyster Creek than in the main stem and 

reflected the source of the tributary. Tributaries draining 

swampy areas, such as tributaries C and F, tended to have higher 

concentrations of total iron and total nitrogen, and lower pH than 

tributaries draining upland areas, such as tributary E. 

Ground-Water Quality 

The ground water in the Oyster Creek basin has higher 

concentrations of many constituents than the surface water. Table 

3 lists the results of chemical analyses of water from the two 

Oyster Creek observation wells (wells 1 and 2) and the two 

Waretown observation wells (wells 3 and 4). The pH of the groundwater samples ranged from 4.9 to 6.5. Specific conductance ranged 

from 35 to 141 wmhos/cm, bicarbonate from 0 to 46 mg/L, and 

chloride from 4.1 to 11 mg/L, with the highest values of each 

measured in well 1. Well 1, which is in the swamp muck deposits 

adjacent to Oyster Creek, also contained the highest concentrations of dissolved solids, ammonia nitrogen, and dissolved and 

total iron. These high concentrations are the result of the 

decomposition of organic matter within the swamp deposits. 

Water from well 2, which taps the Cohansey Sand directly 

beneath the swamp muck deposits, had lower concentrations of most 

chemical constituents than water from well 1. Dissolved solids 

were 41 and 58 mg/L in water from well 2, compared with 78 and 99 

mg/L in water from well 1, and ammonia nitrogen was 0.01 and 0.32 

mg/L in water from well 2, compared with 0.54 and 1.5 mg/L in 

water from well 1. Of the four wells sampled, water from well 2 

had the lowest concentrations of total organic carbon (4.2 mg/L), 

dissolved iron (O mg/L), bicarbonate (0 mg/L), sodium (2.3 mg/L), 

and magnesium (0.2 mg/L), but had the highest measured 

concentration of organic nitrogen (0.61 mg/L). 

16 
Table 3.--Chemical analyses of ground water in the vicinity of Oyster Creek 

[Results in milligrams per liter, except as noted] 

Oyster Creek observation wells Waretown observation wells 

Well 1 Well 1 Well 2 Well 2 Well 3 Well 3 Well 4 

Date 12-05-74 11-05-75 12-05-74 11-05-75 10-23-61 01-20-77 03-15-62 

Temperature (° C) 3.3 13.6 9.8 12.6 14 11.2 12 

pH (units) 6.5 6.2 6.2 4.9 5.8 6. 1 5.9 

Specific conductance 

C11mho/ em) 124 141 79 50 35 -- 51 

Dissolved solids 99 78 58 41 23 24 40 

Total hardness 48 35 28 5 6 4 12 

Calcium 16 12 10 1. 8 .8 1. 0 2.9 

Magnesium 2.0 1. 2' .8 .2 1. 0 .6 1. 2 

Sodium 7.0 5.1 4.0 2.3 4.0 4.7 3.4 

Potassium 1. 8 .9 1. 8 1.1 .8 ' . 6 2.5 

Bicarbonate 46 35 28 0 5 6 6 

Sulfate 7-7 7.9 6.5 7.5 0 .9 10 

Chloride 9.1 11 6.3 4.8 7.6 8.9 4.1 

Ammonia (as N) 1. 5 .54 . 32 .01 -- .01 

Nitrate (as N) .05 0 .06 0 .05 .10 0 

Organic nitrogen .10 . 22 . 61 . 14 -- .06 

Phosphorus .02 . 01 . 02 . 01 

Total Organic Carbon 12 12 7.2 4.2 -- 14 

Dissolved iron 1. 5 5.7 0 .06 -- .44 

Total iron -- 8.8 -- .53 . 10 4.0 . 81 

Total manganese -- . 12 -- .02 0 .01 • 10 

Note: Well 1 taps swanp (Holocene) deposits 

Wells 2 and 3 tap the Cohansey Sand 

Well 4 taps the Kirkwood Formation. 

1--' 

-......] 
Water from well 3, which also taps the Cohansey Sand, had the 

lowest specific conductance (35 wmho/cm), dissolved solids (23 

mg/L), sulfate (O mg/L), and potassium (0. 6 mg/L). One sample 

from well 3 contained 0.10 mg/L of total iron, while a second 

sample contained 4.0 mg/L, of which 0.40 mg/L was dissolved iron. 

Well 4, tapping the Kirkwood Formation, was sampled once. 

This sample had moderate levels of dissolved solids (40 mg/L) and 

total iron (0.81 mg/L) compared with the other ground-water 

samples. Water from well 4 showed low concentrations of chloride 

(4. 1 mg/L), bicarbonate (6 mg/L), sodium (3.4 mg/L), and nitrate 

(0 mg/L), but had the highest measured concentration of sulfate 

( 1 0 mg/ L ) . 

Precipitation Quality 

Precipitation was collected in the Oyster Creek watershed for 

more than 7 months and samples were analyzed at 1 to 3-week 

intervals. The results of the analyses were studied to determine 

the extent precipitation affecte~ water chemistry. The results of 

these chemical analyses are listed in table 4. All samples 

reflect the cumulative rainfall, snowfall, and particulate fallout 

for the period of collection. 

Likens (1976) and other investigators found a trend towards 

increasing acidity in rainfall in the northeastern United States. 

The rise in rainfall acidity is attributed to an increase of 

sulfur dioxide and nitrous oxides in the atmosphere as a result of 

combustion of fossil fuels. The minimum pH value expected of 

rainwater in equilibrium with atmospheric carbon dioxide is 5.6 

( L i k e n s , 1 9 7 6 , p . 2 9 ) . Thus , an y r a in fall pH v a l u e s below 5 . 6 are 

influenced by other chemical constituents. The pH of rainfall 

samples collected at Oyster Creek ranged from 4.2 to 7.0, with 

four of the samples having pH values of 4.6 or less. 

The chemical composition of rainfall on Oyster Creek was 

variable. Chemical composition of rainfall is dependent upon wind 

direction, proximity to the sea, and surrounding land use and 

industrial activity. Most constituents measured in rainfall at 

Oyster Creek had concentrations on the order of those in the 

surface water. Sulfate, calcium, nitrate and organic nitrogen, 

and phosphorus were all present in rainwater in concentrations 

close to surface-water concentrations, indicating that 

precipitation represents a major source of these constituents to 

the watershed. Concentrations of other ions, including potassium, 

sodium, magnesium, and chloride, were generally lower in rainwater, although individual samples of each were higher than the 

average stream concentration. Rainfall may represent a significant source of these ions, depending on atmospheric conditions. 

As an example, during the period January 12 to 27, 1977, 39 mg/L 

of sodium was measured in rainfall, a much higher concentration 

than any measured in surface water over the period of record. An 

onshore wind carrying a sea-salt spray may have been responsible 

18 
,_

Table 4.--Chemical analyses of precipitation at the Oyster Creek rain gage near Brookville, New Jersey 

[Results in milligrams per liter, except as noted] 

Specific 

Rainfall pH conductance 

Period of composite sample (inches) (units) (]Jmho/ em) Calciun Magnesium Sodium Potassiun Chloride Sulfate 

Total 

Hardness 

Sept. 2~14, 1976 ( 1) -- 237 -- -- -- -- -- 14 

Sept. 14 - Oct. 7, 1976 (1) 7.0 112 -- -- -- 8.3 -- 13 

Oct. 7-27, 1976 5.2 5.5 27 0.9 0.5 1. 5 3.0 2.4 5.2 4 

Nov. 23 - Dec. 14, 1976 .6 -- 50 1. 0 .4 1. 8 3.0 4.4 5.8 4 

Dec. 14 - Jan. 4, 1977 1. 0 4.4 53 5.2* .0 . 3 .2 1.7 11 

Jan. 4-12, 1977 3.0 -- 54 -- -- -- -- 6. 1 7.6 

Jan. 12-27, 1977 ( 1 ) 4.6 181 1. 1 .3 39 .7 -- 8.4 4 

. Feb. 25 - Mar. 11, 1977 ( 1 ) 4.2 95 3.6 1. 4 3.8** -- 5.2 15 15 

Mar. 11-18, 1977 1. 4 -- 20 1. 0 .3 .6 .2 1. 4 3.4 4 

Mar . 18-25 , 1977 1. 8 4.4 23 1. 4 .3 1.3 .2 1.7 2.5 5 

Mar. 25 - Apr. 8, 1977 2.0 -- 43 1. 6 1. 5 1. 1 .2 2.4 4.3 10 

Total 

Organic Kj eld ahl Ortho- Dissolved 

Ammon ia-N Nitrate-N Nitrogen Nitrogen Phosphate Phosphorus 

Mar. 18-25, 1977 0.12 0.21 0.08 0.20 0.03 0.01 

(1) Missing record 

Estimated value * ** The value represents sodium plus potassium, by calculation, 

tO
for the high sodium level in rainfall during this period. The 

sodium concentration in rainfall was lower than the corresponding 

stream concentration for all other sampling periods. 

DISCUSSION 

Acidity and pH in Oyster Creek 

The quality of the stream water in Oyster Creek is dependent 

on the quality of the precipitation and ground water which feed 

it. Ground water has a higher pH and higher concentrations ?f 

alkalinity, bicarbonate, and iron. The iron in most natural\ 

ground water, and probably in the ground water near Oyster Creek 

as well, is in the reduced ferrous state. As the ground water 

enters the surface environment and is exposed to the atmosphere, 

the reduced ferrous iron undergoes oxidation and hydrolysis to 

ferric hydroxide, according to the following equation (Langmuir, 

1 96 9' p • 3) : 

( 1 ) 

For every two equivalents of ferrous iron reacted, four 

equivalents of hydrogen ions are produced. If the iron 

concentration is high and the water is poorly buffered, these 

hydrogen ions can significantly decrease the pH. The complete 

oxidation and hydrolysis of 1.0 mg/L of ferrous iron in pure water 

would produce a theoretical pH of 4.4; hydrolysis of 5.0 mg/L 

would drop the pH to 3.7. Well-water samples contained dissolved 

iron concentrations as high as 1.5 mg/L to 5.7 mg/L, which could, 

after hydrolysis, cause substantial decreases in the pH of the 

water after it enters the surface environment. This is probably 

the mechanism by which the pH of ground water is reduced as it 

discharges into Oyster Creek. 

Drainage from swampy areas into the stream also adds acidity, 

particularly during runoff periods. Low pH levels within swamps 

and bogs are the result of several physical and chemical processes 

that liberate hydrogen ions (Ruttner, 1974, p. 223-224). The 

decomposition of organic matter produces carbon dioxide and 

dissolved humic acids, both of which cause acidic reactions. Low 

pH levels within bogs are maintained by the adsorption of bases by 

peat colloids. The living Sphagnum membrane and the peat itself 

have the ability to adsorb the bases from dissolved salts, 

releasing acids. This property enables the bog to maintain 

equilibrium, even with the addition of alkaline waters. 

The chemical factors described above are possible causes for 

the decrease in stream pH as Oyster Creek flows downstream. 

Figure 7 illustrates this trend of decreasing pH values downstream 

for the fall and winter months. Each curve represents the profile 

of pH measured along the creek during 1 day. The pH values 

consistently decreased downstream, with the highest pH occurring 

20 
SAMPLING SITES SAMPLING SITES 

A-20 A-15 A-10 A-3 A-'1 A-20 A-15 A-10 A-2 A-1 

5.0 5.2 

e MEASURED e MEASURED - 4.8. 5.0 ~ 0 ESTIMATED 

4.6 ... ' :I: 4.8 

:I: ' 

·. "':--.. c. c. "e 

::e 4.4 ~».,., '.._., .................. ::e <( 4.6 ' ._.. -- -- <( .... Q -~ ................................... LA.I ., ----

LA.I a: .....__ --.. -- ....... a: •, ~ 

1-- "'• 1-- 4.2 en 4.4 . •, 

... ''0 "' ........ ·~ 

en ···~--- ........ ~-- ... ....... ... ............ 

. ' 

·-- ... .. .. 4.0 .,.,. ... .......... - - ... ............... 1- ....... ...... 4.2 ~ ·-. .. .. ... .. ...... ·- -12-18-75 

............ -2-2-77 ......... 

1- .............. ... .. 3.8 -- 11-21-75 4 0 - - 2-27-76 ........ t . -. - 1-7-76 ........................ -·- 12-8-76 ......... 11-14-75 ........ 1-29-76 

3.6 3.8 

4 3 2 1 0 4 3 2 1 0 

DISTANCE FROM SITE A-1, IN MilES DISTANCE FROM SITE A-1. IN MilES 

Figure 7.-- Profile of pH values along the main stem of Oyster Creek; 1975-1977. 

~ 

I--' 
at the uppermost sampling site, A-20, and the lowest at the gaging 

station, site A-1. 

The pH profile in Oyster Creek during rainfall-runoff periods 

was consistently lower than that during dry-weather periods, as 

shown by the pH curves for November 14, 1975, December 8, 1976, 

and January 29, 1976, all days with above normal discharge. This 

suggests that runoff is a factor in causing drops in pH. 

The pH profile for February 2, 1977, on the other hand, was 

significantly higher than those during normal dry weather periods. 

During the winter of 1977, exceptionally cold temperatures caused 

the ground and swamps surrounding the creek to freeze, leaving 

ground water as the only source of streamflow. The frozen swamps 

were not inputting organic acids and other acidic materials to the 

stream, causing a rise in pH throughout the basin. The stream pH 

during this cold weather period was lower than the ground-water 

pH, however, and continued to decrease in the downstream 

direction, indicating that some chemical reactions producing--~ 

hydrogen ions were still occurring. 

Stormwater runoff and drainage from swamps and bogs are major 

causes of the occurrence of excessively low pH in Oyster Creek. 

Frequency curves of pH were developed for swamp pH and stream pH. 

Figure 8 compares the pH frequency curves of Oyster Creek at site 

A-1, with the adjacent swamp sampling site. Tnese curves show the 

percentage of time a given pH was equalled or exceeded. In the 

stream, where the median pH was 4.5, the pH was 4.0 or higher 94 

percent of the time. The swamp pH, which had a median value of 

3.8 and a minimum of 3.3, was 4.0 or higher only 33 percent of the 

time and was consistently lower than the stream pH at site A-1 by 

half a pH unit or more. The difference between stream and swamp 

pH is particularly noticeable during warm weather, when the 

evaporation and transpiration in the swamps concentrate the 

acidity. 

The difference in pH in the streamflow and the water in 

nearby swamps is maintained during dry-weather because of the 

limited interchange of water between stream and swamp. Large 

storms, however, cause more complete mixing of stream and swamp 

waters, and the addition of the low pH swamp water to the stream 

reduces the pH level of the poorly buffered and already acidic 

streamflow to below 4.0. It is these large and rapid drops in pH 

which are most damaging to aquat~c life. 

The relationship between storms and low pH is illustrated in 

figure 9, which charts daily mean discharge and daily minimum pH 

from April through September 1975. The discharge hydrograph and 

pH graph are approximate mirror images, with peak discharges 

coinciding with low pH levels. All the large pH drops occur 

during fairly large hydrograph peaks, although correlations 

between pH and stream discharge do not show a direct relationship 

bet ween the two. 

22 
5.0 --.--.-~--,---..,--r-.---,---r--,--,----r----r---r-,---,---..-----, 

40 

:X: 

a. 

3.0 

20~~--~--~----~~--~~--~~--~--~--~--~--~----~~----~ 1 2 5 10 20 50 90 95 98 99 99.8 99.99 

PERCENT OF TIME INDICATED pH WAS EQUALLED OR EXCEEDED 

Figure 8.--Graph showing pH frequency curves for site A-l and 

adjacent swamp sampling site; 1974-1977. 

N 

V-l 
Q 90 

2 

0 

(.) 

w 

en 

cc 

w 

c.. 

1-

w 

w 

u. 

S2 

m 

::::> 

(.) 

z 

u.i 

(.!) 

cc 

<( 

::r: 

(.) 

en 

Q 

2 

<( 

w 

~ 

>-

..J 201- ~5.0 

<! 

Q 

I. T\ n I I 

::r: 

Q. 

4.5 ~ 

~ 

2 

:2: 

>-

..J 

=i 4.0 Q 

3.5 

APRIL MAY JUNE JULY AUGUST SEPTEMBER 

gure 9.--Graph showing daily mean discharge and daily minimum pH at site A-1; 

April through September 1975. 

N 

~ 
During the period shown in figure 9, there were eight 

distinct periods during which daily minimum pH values below 4.0 

were recorded and at least five when minimum pH approached 3.5. 

Figure 10 shows the changes in pH recorded by the waterquality monitor during four storms in 1975 and 1976. All 

four plots have a characteristic drop in pH as the stream stage 

begins to rise, although they differ in the sharpness of the drop 

and in the minimum pH attained. Each curve exhibits a small pH 

drop at the beginning of the storm hydrograph, after which the pH 

rises slightly before dropping again. These smaller pH drops are 

caused by the initial runoff following a heavy rainfall. 

Most rainfall does not directly run off the Oyster Creek 

watershed. It infiltrates into the sandy soils or is stored 

within swampy areas. As the water table rises due to the large 

volume of recharge, ground water will be discharged to the stream 

at an increasing rate, causing a gradual rise in the storm 

hydrograph. The rising stream stage and increasing water levels 

within swamp areas bring the two into increasing contact. 

Eventually, the stream flows over its shallow banks and into the 

swamps and mixes with the more highly acidic swamp water, causing 

a rapid drop in stream pH. This flushing appears to occur at 

about a stream gage height of 4.3 to 4.5 ft at site A-1, and a 

discharge of approximately 40 ft 3 /s. This is the point during 

most storms at which a rapid pH drop begins, as shown in figure 

1 0. 

Assuming that the flushing of acidic swamp water is the major 

cause of the high acidity during periods of increased discharge, 

then the minimum pH level in the stream should approach the pH of 

the swamp water. For each storm shown in figure 10, the minimum 

stream pH was compared with the latest pH measured at the swamp 

sampling site before the storm. Three out of four times, the 

minimum stream pH after the storm did approach the pH measured in 

the swamp. Only during the September 1975·storm did the stream pH 

decrease to a lower level than the pH of the swamp. This may be 

due to the fact that the swamp water was sampled at only two sites 

close together and therefore may not be totally representative of 

the large swamp area within the basin. Additional swamp areas 

could not be sampled because of their poor accessibility. 

Effects of Acidity on Trout 

Research by Pyle (1957) has shown that brook trout are 

capable of surviving in waters of .New Jersey where pH is as low as 

4. 3. This level is in close agreement with minimum pH values of 

trout survi~al determined in other studies and listed by McKee and 

Wolf (1963, p. 236). Trout survival is seriously impaired at low 

pH, although the exact physiological causes have yet to be 

defined. Packer and Dunson (1970 and 1972) suggest that the death 

of brook trout at low pH levels (2.0 to 3.5) is due to an 

inhibition of oxygen uptake, a reduction in blood pH, and, to a 

lesser extent, a loss of body sodium. Jones (1964, p. 109) 

25 
4.8 

4.6 

4.4 

1-

w 4.6 5.2 ~ 4.2 

w 

~A u.. 1-

z 

w 

w 5.0 4.0::r:: 4.4 ::r:: u.. ~--~ z c. c. 

::r:: 4.2 4.8 (!) 3.8 t-"' 

::r:: (!) 3.6 4.0 4.6 

jjj 

::r:: 

w 4.4 

(!) 

<( (!) 4.2 

2400 1200 2400 1200 2400 1200 2400 

April 15 April 16 April 17 

1975 1975 

4.6 4.4 

---ESTIMATED 4.4 

4.2 

4.2 

J: -, ~-! r-~ 4.0 c. ::r:: 4.0 

pH 1- ~3.8c. w 3.8 

~ 5.0 tu 4.6 3.6 

z 3.6 w GAGE 

;:: .. z 

u.. HEIGHT 4.8 4.4 

::r:: / 

(!)46 ~~ 4.2 jjj' (!) ::r:: 

w4.4 jjj 4.0 (!) ::r:: 

<( w (!)4.2 ~ 3.8 

(!) 241-0_0_1_2..1,_0_0 _2_4-1...0-0 -12...J..0_0-24-1.0_0_1_120-0-,-, -2---l400 1200 2400 1200 2400 1200 2400 1200 

Dec. 31 Jan. 1 Jan. 2 Jan. 3 Dec. 7 Dec.8 Dec. 9 

1976 1976 

Figure 10.--Graphs showing hourly gage-height and pH at site 

A-1 during four storms; April 1975 to December 1976. 

26 
summarizes experiments by Ellis which show that acidic water kills 

fish by causing precipitation of the mucus on the gills and 

coagulation of the gill membranes. Larsen and Olsen, in research 

cited by Jones (1964, p. 170), found that trout-fingerlings placed 

in acid iron-polluted water died of asphyxiation because the slime 

of their bodies was coagulated with an accumulation of iron ochre 

(ferric hydroxide). The pH range tolerated by fish may be 

affected by other factors, including temperature, dissolved 

oxygen, prior acclimatization, and the concentrations of various 

anions and cations. Work cited by McKee and Wolf (1963, p. 236) 

indicates that fish that can tolerate pH values as low as 4.8 will 

die at pH 5.5 if the water contains 0.9 mg/L of iron. 

Oyster Creek, which has excellent water quality in most 

respects, is subject at times to very low pH. In one 6-month 

period between April and September 1975, pH of 3.5 were recorded 

on five occasions, whereas values below 4.0 were recorded eight 

times over the same period. At these low pH levels, water begins 

to have a toxic effect on fish, particularly in combination with 

the moderately high concentrations of dissolved and suspended iron 

often found in Oyster Creek. The exact cause of death of the 

trout stocked in Oyster Creek was not determined, however. 

An indirect effect of low pH upon fish populations may be the 

limiting of the available invertebrate organisms consumed by 

trout. A qualitative survey of aquatic invertebrates in the 

Oyster Creek basin on August 24, 1978, found no larval insect 

forms or benthic invertebrates at the site of the gaging station 

(Site A-1); although some aquatic adult stages, including water 

striders and other water bugs, were found. Also, no benthic 

invertebrates were seen at Site A-2, which had a muck and gravel 

substratum similar to that at Site A-1. Farther upstream, 

however, at Sites A-10 and A-15, large numbers of benthic 

invertebrates were sampled, including larvae of caddisflies, 

dragonflies, and mayflies. As pH generally is higher in the upper 

reaches of the creek, conditions there may be more favorable for 

invertebrates. The absence of benthic invertebrates in the lower 

reaches of Oyster Creek does not preclude a viable trout 

population, however, as Hynes (1970, p. 367) states that trout 

take great quantities of food at the water surface, and in the 

summer 40 to 50 percent or even more of their food is terrestrial 

insects. 

SUMMARY 

Oyster Creek and its tributaries were sampled for pH and 

other chemical, biological, and physical characteristics to aid in 

developing management techniques for brook trout in acidic streams 

and lakes. The chemical and biological measurements indicate that 

the overall quality of water in Oyster Creek is good, with the 

exception of extremely low pH (3.5-5.8) and low-buffering capacity 

(mean total alkalinity 0.5 mg/L)~ Mean concentrations of 

dissolved solids an~ dissolved oxygen were 28 and 8.7 mg/L, 

respectively, and mean specific conductance was 41 umho/cm. 

27 
Concentrations of nitrogen and phosphorus were low. Total 

phosphorus ranged from 0 to .05 mg/L, with a mean of 0.01 mg/L. 

Dissolved iron and manganese averaged 0.17 and 0.02 mg/L, 

respectively. 

The concentrations of most chemical constituents in the main 

stem of Oyster Creek decreased slightly from the upstream sites ~o 

the downstream sites, with the exception of total nitrogen, which 

increased downstream. The water quality in the tributaries varied 

greatly, according to the source and flow rate of the tributary. 

Concentrations of chemical constituents in ground water were 

generally higher than those in surface water. The maximum 

concentrations of ammonia-nitrogen and dissolved iron in ground 

water were 1.5 and 5.7 mg/L, respectively. Specific conductance 

was 35 to 141 ~mho/em, and dissolved solids were 23 to 99 mg/L. 

The normal acidic conditions (pH 4.0-5.0) in the Oyster Creek 

basin are the result of natural processes. The creek is fed 

largely by slightly acidic ground water. Oxidation and hydrolysis 

of iron and the formation of humic acids and other acids by the 

oxidation of organic materials may combine to increase the acidity 

of this ground water as it enters and flows through the stream. 

These acid-producing reactions are prevalent within the swamp 

areas, where pH is typically half a unit or more below those in 

the creek. 

Rapid drops in stream pH to below 4.0 are caused by the 

mixing of poorly buffered stream water and more highly acidic 

swamp water during heavy runoff. 

Acidic water of pH less than 4.0 has killed brook trout in 

several experiments. The exact physiological changes associated 

with the death of fish at low pH have not been determined, 

although research indicates an inhibition of oxygen uptake, a 

reduction in blood pH, a loss of body sodium, and coagulation of 

mucus and gill membranes in fish at low pH levels. 

28 
SELECTED REFERENCES 

Anderson, H. R., and Appel, C. A., 1969, Geology and groundwater resources of Ocean County, New Jersey: New Jersey 

Department of Conservation and Economic Development, 

Division of Water Policy and Supply Special Report 29, 

7 4 p. 

Hem, J. D., 1970, Study and interpretation of the chemical 

characteristics of natural water: U.S. Geological 

Survey Water-Supply Paper 1473, 363 p. 

Hem, J. D., and Roberson, C. E., 1967, Form and stability of 

aluminum hydroxide complexes in dilute solution: U.S. 

Geological Survey Water-Supply Paper 1827-A, 55 p. 

Hutchinson, G. E., 1957, A treatise on limnology, v. 2, 

Geography, Physics, and Chemistry: New York, John 

Wiley, 1015 p. 

Hynes, H. B. N., 1970, The ecology of running waters: 

Bungay, Suffolk, Great Britain, Richard Clay Ltd., 

555 p. 

Jones, J. R. E., 1964, Fish and river pollution: Washington, 

D.C., Butterworths, 203 p. 

Langmuir, Donald, 1969, Iron in ground water of the Magothy 

and Raritan Formations in Camden and Burlington 

Counties, New Jersey: New Jersey Department of 

Conservation and Economic Development, Division of 

Water Policy and Supply Water Resources Circular 19, 

49 p. 

Likens, G. E., 1976, Acid precipitation: Chemical and 

Engineering News, v. 54, no. 48, p. 29-44. 

McKee, J. E., and Wolf, H. W., 1963, Water quality criteria 

( 2nd e d . ) : Cal i for n i a S t a t e Wa t e r Re so u r c e s Con t r o l 

Board Publication 3-A, 548 p. 

Packer , R . K. , and Dun son , W . A . , 1 9 7 0 , Effect s o f low 

environmental pH on blood pH and sodium balance of 

brook trout: Journal of Experimental Zoology, v. 174, 

p. 65-72 

Packer, R. K., and Dunson, W. A., 1972, Anoxia and sodium 

loss associated with the death of brook trout at low pH: 

Comparative Biochemistry and Physiology, v. 41A, 

p. 17-2 6 

29 
SELECTED REFERENCES, Continued 

Pyle , A . B . , 1 9 5 7 , Pr e l i m in a r y r e p or t o f s t ud i e s on t h e 

ability of trout to withstand various acidities in 

New Jersey streams: New Jersey Department of 

Conservation and Economic Development, Division of 

Fish and Game Miscellaneous Report no. 20, 9 p. 

Rainwater, R~ H~, and Thatcher, L. L., 1960, Methods for 

collection and analysis of water samples: U.S. 

Geological Survey Water-Supply Paper 1454, 300 p. 

Rhodehamel, E. C., 1970, A hydrologic analysis of the 

New Jersey Pine Barrens region: New Jersey 

Department of Environmental Protection, Division 

of Water Policy and Supply Water Resources Circular 

22, 35 p. 

Rho d e hamel , E . C . , 1 9 7 3 , Ge o log y and w a t e r r e so u r c e s o f the 

Wharton Tract and the Mullica River basin in southern 

New Jersey: New Jersey Department of Environmental 

Protection, Division of Water Resources Special Report 

36, 58 p. 

Riggs , H. C . , 1 9 7 2 , Low-flow investigations : U. S. Geologic a l 

Survey, Techniques of Water-Resources Investigations 

Bo o k 4 , Ch a p t e r B- 1 , p . 1 - 1 8 . 

Ruttner, Franz, 1953, Fundamentals of limnology: 

Toronto, University of Toronto Press, 307 p. 

Searcy, J. K., 195 9, Flow-duration curves; Manual of 

hydrology, part 2, Low-flow techniques: U.S. 

Geological Survey Water-Supply Paper 1542-A, 

p. 1-33. 

Skougstad, M. W., Fishman, M. J., Friedman, L. C., Erdmann, D. E., 

and Duncan, S. S., 1979, Methods for determination of 

inorganic substances in water and fluvial sediment: U.S. 

Geological Survey, Techniques of Water Resources 

In v e s t i g at ion s , Boo k 5 , Ch a pte r A- 1 , 6 2 6 p . 

U.S. Department of Agriculture, 1977, Interim soil survey 

report, Ocean County, New Jersey (southern part): 

U . S . So i l Con s e r v at ion Se r v ice , 7 1 p . 

U.S. National Oceanic and Atmospheric Administration, 

1966-77, Climatological data, New Jersey: Environmental 

Data Service, Ashville, North Carolina, released monthly. 

30