Hydrogeologic Setting and Conceptual

Hydrologic Model of the Spring Creek

Basin, Centre County, Pennsylvania,

June 2005

By John W. Fulton, Edward H. Koerkle, Steven D. McAuley, Scott A. Hoffman, and

Linda F. Zarr

U.S. Department of the Interior

U.S. Geological Survey

U.S. Geological Survey, Reston, Virginia: 2005

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

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

Purpose and Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Description of Study Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Physical Characteristics of Spring Creek Basin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Climate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Precipitation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Air Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Humidity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Soils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Geology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Surface Water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Ground Water. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Aquifer Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Water Levels. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Wells and Springs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Water Quality. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

Surface Water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Ground Water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Carbonate-Bedrock Valleys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Hydrologic Boundaries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Surface Water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Ground Water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Suggestions for Future Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Summary and Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

References Cited. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

[On CD-ROM in pocket]

2. Tables included in the relational database provided on CD-ROM in Appendix 2. . . . . . . . . . . . . . . . . . . . .6

3. Meteorological data-collection stations in and within 15 miles of the Spring Creek Basin,

4. Average daily pan evaporation for the growing season, in inches, at Raystown Lake,

5. Elevation, slope, and aspect, by subbasin, of the Spring Creek surface-water basin,

6. Selected data for surface depressions, sinkholes, caves, and surface mines reported

7. Summary of multiresolution land-cover classes, by subbasin, in Spring Creek

County, Pa. (fig. 1), and drains an area of approximately

175 mi

. The basin is undergoing rapid growth and develop-

with assistance from the Spring Creek Watershed Community

(SCWC) and the Spring Creek Watershed Commission

(SCWCm), has developed a Watershed Plan (Plan) to assist

This Plan includes future development of a fully coupled

numerical model that dynamically links surface water, ground

water, and land-use changes. The Plan includes completion of

the following tasks before development of the numerical

model: compilation and evaluation of existing data sets con-

cerning the physical and hydrogeologic characteristics of the

basin; (2) presents a conceptual model of the surface-water and

ground-water system; and (3) identifies additional data needs

and tasks to define the interaction of surface water and ground

water within the basin. Basin characteristics such as climate,

physiography, topography, land use, soils, and geology are pre-

sented; surface-water and ground-water systems are described;

and a summary of surface- and ground-water-quality character-

istics is presented. The conceptual model is presented as a sim-

plified representation of the hydrologic system and is illustrated

with block diagrams, generalized cross sections, and schematic

surface-water and ground-water basins may coincide in some

basins, this is not the case for the Spring Creek Basin. In this

Physical Characteristics of Spring Creek Basin 9

[NAD 83, North American Datum of 1983; NAVD 88, North American Vertical Datum of 1988; na, not applicable; Y, yes; N, no; --, no data]

Gas Well 410132 775131 2,050 1/1/2000 to present Hourly na YNNNNNNIFLOWS

Rock Springs 404319.2 775555.2 1,210 9/10/1999 to present Hourly na YNYYYYYPSU

University Park

airport

405031.2 775034.8 1,239.8 1/1/2003 to present Daily na YYYYYYYPACLIM

Clarence 410300 775700 1,389.7 8/1/1950 to present Daily 0700 YYNNNNNNCDC

Lewistown 403500 773400 459.9 5/1/1948 to present Daily 0800 YYYNNNNNCDC

Millheim 405300 772800 1,119.8 6/1/1949 to present Daily 0700 YYNNNNNNCDC

Philipsburg 2 S 405200 781300 1,719.7 4/1/1998 to present Daily Unknown YYYNNNNNCDC

Service radar

Pennsylvania State

University

404735 755202 -- 1/1/1896 to present Daily 0700 YYYNNNN PSU

National Weather Service, 2005.

Pennsylvania State University, 2005.

Pennsylvania State Climatologist, 2005.

Air-temperature records are available for eight locations

(fig. 2 and table 3). Seven of those locations record daily mini-

mum and maximum temperatures, and one location records

Humidity is a measure of water vapor in the air, and water

vapor is a significant source of latent heat. In the eastern United

States, humidity levels can be high enough to be a substantial

source of heat and, thus, warrant inclusion in a modeled snow-

melt process (George Leavesley, U.S. Geological Survey, writ-

ten commun., 2003). Hourly humidity data are available for one

location and daily humidity data are available for one location

within the Spring Creek Basin (table 3). The average annual rel-

ative humidity for Centre County is about 70 percent.

for the period January 1961 through December 31, 1990 (Penn-

sylvania State Climatologist, 2003). Solar-radiation data also

were collected at the Pennsylvania State University from 1952

to about 1985 and are archived as paper copies (Pennsylvania

State Climate Office, written commun., 2003). A new solar-

sylvania State University Rock Springs agricultural research

farm as part of the National Oceanic and Atmospheric Admin-

istration (NOAA) SURFRAD Network (National Oceanic and

Atmospheric Administration, 2003). Solar-radiation data for

In hydrologic modeling, ET is a major component of the

hydrologic budget. ET typically is either computed from other

data. Pan evaporation is the most commonly collected type of

evaporation data.

oration at Raystown Lake, Huntingdon County, 30 mi south-

Climatologist, 2003). Total annual pan-evaporation values are

available from the Rock Springs meteorological station (Penn-

sylvania State Climatologist, 2003). Rock Springs is in Fergu-

son Township, about 2 mi southwest of the Spring Creek Basin.

Free water surface (FWS) evaporation is considered a bet-

ter estimate of potential ET than pan evaporation. FWS evapo-

to pan-evaporation data. Farnsworth and others (1982) assigned

a pan coefficient of 0.76 to the area near Spring Creek Basin.

This coefficient is an average annual value. Monthly pan coef-

ficients would be preferred for modeling purposes.

Big Hollow 17.1 1,201 2.3 12.6 7.2 0.7 166

Buffalo Run 27.3 1,245 6.0 35.5 13 .8 182

Cedar Run 17.5 1,321 3.8 28.2 3.2 .5 185

Galbraith Gap Run 5.13 1,767 9.3 27.4 4 3.1 199

Logan Branch 22.5 1,308 5.9 33.8 9.2 2.1 218

Roaring Run 4.72 1,580 8.2 29.7 4.2 3.3 242

phy of the basin. Bald Eagle, Tussey, and Nittany Mountain

agriculture and urban (fig. 8). The headwaters area and

extended ground-water basin in the southwest part of the basin

also are primarily forested with limited agriculture or urban

land use. A summary of land cover derived from the USGS/U.S.

Environmental Protection Agency Multi-Resolution Land

Characteristics 1992 (MRLC1992) (U.S. Geological Survey,

1992) GIS data set (fig. 8) is presented by subbasin in table 7.

The scale of MRLC1992 is 1:100,000.

Higher-resolution GIS data are being developed by the

Land-cover classes can be used as a primary guide for

assigning specific hydrologic/hydraulic characteristics to the

spatial framework of a hydrologic model. Not included in the

listed land-cover classifications is an accounting of pervious

and impervious areas. Models that simulate runoff/infiltration

from rainfall input typically apply rainfall to delineated pervi-

vious areas. However, this approach may not adequately simu-

[na, not applicable]

ceous wetland

Evergreen forest .474 2.8 .735 2.7 .11 .6 .82 16 1.121 5 .433 9.2 .417 2.5 .762 2.2 4.877 3.3

Hay/pasture 1.37 8 1.541 5.7 2.163 12.4 .031 .6 1.032 4.6 .208 4.4 1.498 8.9 2.817 8.1 10.656 7.3

High-intensity com-

mercial/

industrial

.346 2 .042 .2 .006 0 .002 0 .384 1.7 .001 0 .328 1.9 .49 1.4 1.596 1.1

High-intensity resi-

dential

.188 1.1 .023 .1 .001 0 na na .029 .1 na na .381 2.3 .222 .6 .844 .6

Low-intensity

developed

Total percent of land-cover classes for an individual subbasin may not equal 100 percent because of rounding.

Ordovician Juniata Formation 500-1,000 Dominately red, fine-grained sandstone, siltstone, and shale Fracture-dominated siliciclastic (except

Salona Formation 180-300 Thin-bedded limestone containing shale partings Conduit-dominated carbonate

Nealmont Formation 70 Thin to thick impure limestone Conduit-dominated carbonate

Benner Formation: 150 Dark-gray laminated, thick- to thin-bedded limestone Conduit-dominated carbonate

Valentine Member

Snyder Formation 80 Medium-bedded limestone and dolomite Conduit-dominated carbonate

Hatter Formation 75 Medium-bedded limestone and laminated, argillaceous and arenaceous

Loysburg Formation 50-450 Laminated, medium- to thin-bedded limestone and dolomite Conduit-dominated carbonate

Stonehenge Formation 250-600 Blue, thin-bedded limestone; some dolomite Conduit-dominated carbonate

Cambrian Gatesburg Formation: 1,800 Conduit-dominated carbonate

Mines Member

upper sandy member

Indicates geologic name not currently used by the U.S. Geological Survey. Conforms to usage by the Pennsylvania Geological Survey.

Hydrogeologic Setting of Spring Creek Basin 25

size from 4.72 to 34.9 mi

small tributaries carry mountain runoff into basin-valley

streams. However, during low to moderate flow conditions,

base of the ridges that delimit Spring Creek Basin (Giddings,

1974). This lost runoff is discharged to surface waters through

the numerous springs on the valley floor of the basin. Spring

Creek flows northeast and discharges to Bald Eagle Creek,

a similar size watershed at Beech Creek at Monument, Pa.

at Milesburg (fig. 15). Daily mean base flows are between 100

and 200 ft

/s)/mi

In the Spring Creek Basin, the total volume of surface-water

discharges exceeds surface-water withdrawals, because

ground-water withdrawals supply the majority of facilities hav-

ing surface-water discharges. Records of withdrawal volumes

generally do not exist. Small residential and commercial facili-

ties are not required to monitor discharge volumes. In many

instances, these facilities are permitted on the basis of an

expected volume for the stated type of discharge. Continuous or

partial records for some facilities (mostly larger dischargers)

[NAD 83, North American Datum of 1983; NAVD 88, North American Vertical Datum of 1988; na, not available]

405435007747301 BUL Lower Buffalo Run na 14.2 405435 774738 748 6.3 35.5 August 1999 to present

405112007753301 BUU Upper Buffalo Run na 12.6 405112 775328 1,003 5.4 25.3 August 1999 to present

404739007747501 CEL Lower Cedar Run na 17.5 404739 774750 1,036 3.8 28.2 1990-1994, November 1998

405426007746501 LOL Lower Logan Branch na 4.44 405426 774655 750 3.7 19.1 February 1999 to present

405233007745501 LOU Upper Logan Branch na 18.1 405233 774550 874 6.4 33.8 August 1999 to present

404844007749501 SLL Lower Slab Cabin Run na 1.96 404844 774955 944 2.8 9.5 June 1999 to present

404706007750101 SLU Upper Slab Cabin Run na 10 404706 775008 1,031 4.8 26.2 1990-1994, November 1998

01546400 Spring Creek at

58.5 November 1984 to

01546500 Spring Creek near

87.2 October 1940 to

01547100 Spring Creek at

Reservoir

Public Supply Tributary to Spring

ity, Shingletown Gap Reservoir

Public Supply Roaring Run Active ND Yes

tion

Commercial Spring Creek Active ND Yes

GWC

Station

INDWW Spring Creek Active 9.216 Yes

Discharge Pennsylvania State University GWC Big Hollow Run Active 0.0072 Unknown

Creek

Discharge Pleasant Gap Fish Culture Station INDWW Logan Branch Active 5.508 Yes

Creek

Discharge Science Prk Recreation Association INDWW Tributary to Big Hollow

Run

Creek

Discharge Superior Services of Pa., Inc. STMW Tributary to Spring

Creek

Discharge Tolan, William STP Tributary to Buffalo

Run

Creek Pollution Control Facility

Discharge United Parcel Service, Inc. STMW Tributary to Spring

Creek

charge rate in the ground-water basin at about 19 Mgal/d, and

5.9 Mgal/d of that is withdrawn for water supply. This spring is

downslope in the valley from the Birmingham Thrust Fault. The

discharge rate from 1986 to 2003 is plotted in figure 21. The

weir used to determine the discharge rate was improved in

2002, which accounts for the increase in measured discharge.

Springs that discharge from limestone and dolomite have

been classified into two types by Shuster and White (1971). In

diffuse springs, water flows at low velocities along joints, frac-

tures, and bedding planes, which are generally less than 1 in.

water withdrawal rates available from State College Borough

Water Authority during 1980-2002, from the Pennsylvania

State University during 1994-2002, and from College Town-

ship only during 2000-02 (Max Gill, State College Borough

Water Authority, written commun., 2003; John Gaudlip, Penn-

sylvania State University, written commun., 2003; Gary Will-

iams, College Township, written commun., 2003). These with-

drawal data are for public supply only and are presented in

table 17. Ground-water withdrawals for private supply have not

been compiled. Ground-water withdrawals for industrial or

3 Mgal/d to over 9 Mgal/d in 2002. Because of the lack of with-

incomplete estimates of total withdrawals. The withdrawals are

mated at 125 Mgal/d. Although the pumpage will result in low-

ered water levels locally, the total withdrawals are small com-

pared to total recharge rates. The total allocations of the water-

supply companies and authorities may result in a larger percent-

age of the recharge being used for supply. During years of low

precipitation, such as 1969, 1968, and 2001, the ground-water

recharge was much less (73, 87, and 92 Mgal/d, respectively).

would result in lowering of water levels below present levels,

and the recovery of water levels in deep ground-water-flow sys-

est in the summer and probably reflect greater usage of water

recharge when evapotranspiration is high.

The pumpage in the Spring Creek Basin is distributed

throughout much of the study area but is concentrated in the

vicinity of State College and farther west in Nittany Valley

where the productive Gatesburg Formation aquifer is present.

The 2002 average annual pumpage rates for public supply are

illustrated in figure 24.

Water-quality data for the Spring Creek Basin have been

collected at various locations and for various constituents for

from spring discharges are also of importance because of the

large contribution to surface-water discharge from springs in

the Spring Creek Basin. A summary of the water-quality data is

presented in table 18 (at the back of the report).

Surface-water-quality data for Spring Creek Basin include

odic sample data. These data include physical and chemical

streamflow-gaging station 01546500 (fig. 14). Water quality at

USGS. The suite of constituents sampled has changed over

time. An inventory of current (2003) and historical water-qual-

ity data at this site is listed in table 19 (at the back of the report).

Beginning in 1999, the SCWC began collecting compre-

hensive water-quality data at 12 locations in Spring Creek

Basin. Six of these sites are collocated with existing stream-

flow-gaging stations operated by the Pennsylvania Cooperative

Fish and Wildlife Research Unit or by the USGS. An inventory

ner, 1992). Karst conceptual models are physical in nature and

describe the hydrologic connectivity between recharge areas,

hydraulic properties, and geology that controls the way in

which water is added, stored, conveyed, and discharged through

the system (White, 2003). Because of the variability in land use

and the hydrologic complexity of the Spring Creek Basin, the

conceptual model must consider the integration of surface water

and ground water to (1) account for the physical exchange of

water, and (2) identify the processes that influence source

rock upland and of the carbonate-bedrock valley. These con-

cepts are discussed below and illustrated in figure 26.

exceeds the infiltration capacity of the soil or (2) saturation

excess where the soil above the water table or perched surface

produces runoff. The former is known as partial source-area

contributions (PSAc) and the latter as variable source-area con-

tributions (VSAc) It is rare that overland runoff is created by

infiltration excess from vegetated cover in humid regions such

as the Spring Creek Basin, where vegetation protects the soil

the soil structure is maintained. In contrast, PSAc may develop

basin that regularly contribute overland runoff.

Saturation excess related to VSAc occurs when the unsat-

urated zone is not capable of transmitting subsurface stormflow

(interflow), and the soil becomes saturated. If the rate of subsur-

its capacity to be transmitted, the excess stormflow returns to

the surface as runoff. As precipitation continues, the saturated

area grows in extent, increasing the area capable of generating

runoff (Cornell University, Soil and Water Laboratory, 2005).

VSAc tend to expand and contract depending on the intensity

above the water-table surface also supplies water to streamflow.

Typically, runoff forms adjacent to drainage ways (near con-

the bottom of hill slopes such as Galbraith Gap Run, Logan

Bald Eagle, and Roaring Run. These saturated areas expand

along hollows or where the water table is close to the ground

surface (Larry Fennessey, Sweetland Engineering and Associ-

ates, written commun., 2005).

ness, available water-storage capacity, depth to bedrock, soil

hydraulic properties, water table or perched water depth,

hydrology of the upland-subbasin area, and local topography.

basin differ relative to their underlying geology, soil, slope,

Run, and Roaring Run are well vegetated, are located along

steep slopes, and possess soil mantles that are thin with high

infiltration capacities. Runoff from these subbasins is produced

when subsurface flow saturates the soil above the water-table

surface near the bottom of hill slopes and near streambanks as

streams within gaps (Buffalo Run, Roaring Run, and Galbraith

Gap Run) and receive mountain runoff. Water within the

streams may be lost by infiltration through the streambed.

Streamflow is discharged directly to sinkholes or flows into

tributaries to Spring Creek. Depending on the hydraulic head

water elevation, the exchange could be substantial.

Mountain (headwaters of Cedar Run and Logan Branch), and

act as ground-water divides (figs. 11 and 12). Because the

R

FDCAFDCA

FDCA

C

D

C

A

R

CDCA CDCA

X

X

X

X

X

X

X

X

X

X

T

ussey

X X X X X X X X X X X X X X X X X X X X X X X X X X

FDSA

CDCA

FDCA

Based on the information collected to date, a number of

data gaps exist and would need to be addressed prior to devel-

opment of a numerical model. In this section, additional data-

2. Collect additional transmissivity and storage data,

3. Develop anisotropy values for bedrock units and bedrock

4. Investigate how transmissivity values have been

5. Review specific capacity and well-productivity results,

for the basin. Available GIS and hydrologic data sets are sum-

The bedrock aquifers have been conceptualized according

pathways (after Parizek, 1984): (1) direct infiltration of precip-

hydrologic simulation models of the Spring Creek Basin. For

example, collection of additional data would be needed to

define aquifer properties, additional synoptic stream and

spring-flow measurements would be needed for model calibra-

hydrologic simulation models.

The Project Management Team (PMT) for this effort

includes groups that either contributed support or provided

Department of Environmental Protection.

We would like to thank the following groups and individ-

uals for contributing to the success of this study:

Anderson, M.P., and Woessner, W.W., 1992, Applied ground-

Braker, W.L., 1981, Soil survey of Centre County,

Butts, C., and Moore, E.S., 1936, Geology and mineral

2005, 2005 Class A wild trout waters: Harrisburg, Pa.,

accessed July 20, 2005, at http://www.fish.state.pa.us.

Pennsylvania: University Park, Pa., The Pennsylvania State

University, Ph.D. dissertation, 393 p.

Experimental Climate Prediction Center, 2005, GCIP Water

and energy budget synthesis (WEBS)—Physiography:

accessed April 25, 2005, at http://ecpc.ucse.edu/gcip/html/

chap2.htm

oration atlas for the contiguous 48 United States: National

Oceanic and Atmospheric Administration Technical Report

NWS 33, 26 p., 4 pl.

Pennsylvania State University, Ph.D. dissertation, 366 p.

Freeze, R.A., and Cherry, J.A., 1979, Groundwater:

Englewood Cliffs, N.J., Prenctice-Hall, Inc., 604 p.

Gannett Flemming, Inc., 2000, Spring Creek Watershed Sur-

face and Groundwater Boundary Map.

Giddings, M.T., 1974, Hydrologic budget of Spring Creek

Drainage Basin, Pennsylvania: University Park, Pa., The

Pennsylvania State University, Ph.D. dissertation, 76 p.,

2 pls., 13 figs.

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