U.S. Department of the Interior

U.S. Geological Survey

Scientific Investigations Report 2009–5173

Prepared in cooperation with the

Town of Caroline and Tompkins County Planning Department

Geohydrology and Water Quality of the Valley-Fill Aquifer 

System in the Upper Sixmile Creek and West Branch

Owego Creek Valleys in the Town of Caroline,

Tompkins County, New York
Cover. Donald Sherwood of USGS collecting a groundwater sample from the artesian flowing well at the Town of Caroline, Town 

Hall, November 30, 2004.
Geohydrology and Water Quality of the 

Valley-Fill Aquifer System in the Upper 

Sixmile Creek and West Branch Owego 

Creek Valleys in the Town of Caroline, 

Tompkins County, New York

By Todd S. Miller

Prepared in cooperation with the 

Town of Caroline and Tompkins County Planning Department

Scientific Investigations Report 2009–5173

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

KEN SALAZAR, Secretary

U.S. Geological Survey

Marcia K. McNutt, Director

U.S. Geological Survey, Reston, Virginia: 2009

For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, 

natural hazards, and the environment, visit http://www.usgs.gov or call 1-888-ASK-USGS

For an overview of USGS information products, including maps, imagery, and publications, 

visit http://www.usgs.gov/pubprod

To order this and other USGS information products, visit http://store.usgs.gov

Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the 

U.S. Government.

Although this report is in the public domain, permission must be secured from the individual copyright owners to 

reproduce any copyrighted materials contained within this report.

Suggested citation:

Miller, T.S., 2009, Geohydrology and water quality of the valley-fill aquifer system in the upper Sixmile Creek and 

West Branch Owego Creek valleys in the Town of Caroline, Tompkins County, New York: U.S. Geological Survey 

Scientific Investigations Report 2009–5173, 56 p. (Also available online at http://pubs.usgs.gov/sir/2009/5173.) 
iii

Contents

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

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

Purpose and Scope ..............................................................................................................................2

Description of Study Area ...................................................................................................................4

Previous Studies ...................................................................................................................................7

Data Collection...............................................................................................................................................7

Geologic Data........................................................................................................................................7

Seismic-Refraction Surveys ...............................................................................................................7

Well Inventory, Test Drilling, Groundwater-Level and Streamflow Measurements..................7

Water-Quality Sampling and Analysis...............................................................................................8

Geology............................................................................................................................................................8

Bedrock Scouring.................................................................................................................................9

Wisconsinan Drift .................................................................................................................................9

Depositional Facies ..................................................................................................................11

Facies 1—Ice-Contact Deposits ....................................................................................11

Facies 2—Proglacial Lake Deposits .............................................................................11

Facies 3—Late- and Post-Glacial Deposits .................................................................13

Valley Heads Readvance .........................................................................................................13

Hydrology of the Valley-Fill Aquifer System............................................................................................13

Aquifer Geometry................................................................................................................................16

Unconfined Aquifers .................................................................................................................16

Confined Aquifers and Confining Units ..................................................................................19

Bedrock Aquifers.......................................................................................................................21

Groundwater Levels and Flow Paths...............................................................................................23

Climate Response Network Well.............................................................................................25

Groundwater Recharge .....................................................................................................................28

Unconfined Aquifers .................................................................................................................28

Direct Infiltration of Precipitation on the Valley Floor ................................................28

Unchanneled Runoff and Groundwater Inflow from Adjacent Hillsides .................29

Seepage Losses from Upland Tributaries.....................................................................29

Confined Aquifers ......................................................................................................................31

Groundwater Discharge ...................................................................................................................31

Seepage to Streams..................................................................................................................32

Tributaries ..........................................................................................................................32

Sixmile Creek ....................................................................................................................32

Pumped Withdrawals and Water Availability .......................................................................33

Breaching of the Confining Unit at Slaterville Springs........................................................36

Water Quality................................................................................................................................................37

Surface Water.....................................................................................................................................38

Physical Properties ...................................................................................................................38

Common Inorganic Constituents.............................................................................................38

Nutrients......................................................................................................................................43
iv

Figures

1. Map showing location of seventeen unconsolidated aquifer reaches in Tompkins 

County, New York..........................................................................................................................3

2. Map showing physiographic features and location of upper Sixmile Creek valley 

and West Branch Owego Creek valley study area in Tompkins County, New York...........4

3. Map showing location of lower Sixmile Creek basin, and the valley-fill aquifer 

extending across the upper Sixmile Creek basin and in the headwaters of West 

Branch Owego Creek basin, Town of Caroline, New York.....................................................5

4. Map showing shaded relief and boundary of valley-fill aquifer in the upper Sixmile 

Creek valley and the headwaters of West Branch Owego Creek valley, Town of 

Caroline, New York .......................................................................................................................6

5. Map showing surficial geology of the valley-fill aquifer in upper Sixmile Creek

 valley and part of West Branch Owego Creek valley, Town of Caroline, New York.......10

6. Map showing well locations in the upper Sixmile Creek valley and West Branch 

Owego Creek valley, Town of Caroline, New York ................................................................12

7. Map showing aquifer types in upper Sixmile Creek and West Branch Owego 

Creek valley, Town of Caroline, New York ..............................................................................14

8. Diagram showing geohydrologic units section A–A’ along the thalweg of the 

upper Sixmile Creek valley and West Branch Owego Creek valley, Town of 

Caroline, New York .....................................................................................................................15

9. Diagram showing well log of Climate Response Network well TM1968, near 

Slaterville Springs, New York ...................................................................................................17

10. Map and diagram showing seismic-refraction survey B–B’ along Flatiron Road, 

Town of Caroline, New York: A location of line of section, and B seismic profile ..........18

11. Map and diagram showing seismic-refraction surveys. Town of Caroline, New 

York: (A) location of surveys C–C’ (north of Landon Road) and D–D’ (along 

VanDemark Road) in upper Sixmile Creek valley, (B) seismic profile C–C’ north 

of Landon Road, and (C) geohydrologic section D–D’ along VanDemark Road...............20

12. Map showing water table in the unconfined aquifer and potentiometric surface 

in the upper confined aquifer in upper Sixmile Creek valley and West Branch 

Owego Creek valley, Town of Caroline, New York ................................................................24

13. Map showing the potentiometric surface in the basal confined aquifer in 

upper Sixmile Creek valley, Town of Caroline, New York.....................................................26

14. Diagram showing well log and construction details of USGS test wells TM 994 

and TM1967 at Caroline Elementary School near Slaterville Springs, New York ............27

15. Hydrograph showing the water level below land surface from January 1, 2005, to

December 31, 2007, in U.S. Geological Survey Climate Response Network well

TM1968 .........................................................................................................................................29

Groundwater........................................................................................................................................43

Physical Properties ...................................................................................................................44

Common Inorganic Constituents.............................................................................................44

Nutrients......................................................................................................................................44

Groundwater Age Dating..........................................................................................................44

Summary........................................................................................................................................................47

References Cited..........................................................................................................................................48

Appendix 1. Records of selected wells in upper Sixmile Creek valley and part of West 

Branch Owego Creek valley, Town of Caroline, New York......................................................51
v

16. Diagram showing sources of recharge to and discharge from valley-fill aquifers

in New York..................................................................................................................................30

17. Photograph showing the volumetric measurement of a tributary entering 

200 feet upstream of Sixmile Creek at Brooktondale, NY, streamgage on 

July 16, 2007.................................................................................................................................32

18. Graphs showing discharge for Sixmile Creek at Brooktondale, New York (USGS 

streamgage ID number 04233286) for (A) water year 2003, (B) water year 2004, 

(C) water year 2005, and (D) water year 2006 ........................................................................34

19. Graphs showing results of hydrograph separation analyses for Sixmile Creek at

Brooktondale, New York (upper Sixmile Creek basin) and Sixmile Creek at Bethel

Grove, New York (lower Sixmile Creek basin) streamgag for theperiod 2003–07............36

20. Hydrograph of groundwater levels in monitoring well TM 999 near bridge over

Buffalo Road, from August 7, 1993, to November 7, 1994, Slaterville Springs, 

New York ......................................................................................................................................37

21. Map showing the location of groundwater and surface-water sampling sites in

upper Sixmile Creek valley and West Branch Owego Creek valley, Town of

Caroline, New York .....................................................................................................................41

22. Diagrams illustrating variability in major ion composition of surface water

and groundwater in the lower Sixmile Creek and West Branch Owego Creek

valleys, Town of Caroline, New York........................................................................................42

23. Photograph showing the Deer Licks historic highway marker along the side of

Valley Road, Town of Caroline, New York...............................................................................43

Tables

1. Range, mean, and median reported well yields and well depths in the Sixmile

Creek and West Branch Owego Creek valley-fill aquifer, Town of Caroline, 

NewYork .......................................................................................................................................23

2. Physical properties, and concentrations of inorganic constituents and nutrients 

in surface-water samples from Sixmile Creek at Brooktondale, New York, 

2003–2005 .....................................................................................................................................39

3. Physical properties, and concentrations of inorganic constituents and nutrients 

in surface-water samples from selected tributaries in upper Sixmile Creek basin

and in West Branch Owego Creek basin, New York, 2004–2005 ........................................40

4. Physical properties, and concentrations of inorganic constituents and nutrients 

in groundwater samples from upper Sixmile Creek and West Branch Owego 

Creek valley, 2004–2005 .............................................................................................................45

5. Data on apparent groundwater ages from groundwater samples collected from

three wells that tap the confined valley-fill aquifers in upper Sixmile Creek valley,

Town of Caroline, New York ......................................................................................................46
vi

Conversion Factors and Datum

Multiply By To obtain

Length

inch (in.) 2.54 centimeter (cm)

foot (ft) 0.3048 meter (m)

mile (mi) 1.609 kilometer (km)

Area

square foot (ft2) 929.0 square centimeter (cm2)

square foot (ft2) 0.09290 square meter (m2)

square mile (mi2) 2.590 square kilometer (km2) 

Volume

gallon (gal) 3.785 liter (L) 

gallon (gal) 0.003785 cubic meter (m3) 

million gallons (Mgal) 3,785 cubic meter (m3) 

cubic foot (ft3) 0.02832 cubic meter (m3) 

Flow rate

foot per year (ft/yr) 0.3048 meter per year (m/yr)

cubic foot per second (ft3/s) 0.02832 cubic meter per second (m3/s)

cubic foot per second per square mile 

[(ft3/s)/mi2]

 0.01093 cubic meter per second per square 

kilometer [(m3/s)/km2]

cubic foot per year (ft3/yr) 0.02832 cubic meter per year (m3/yr)

gallon per minute (gal/min) 0.06309 liter per second (L/s)

gallons per day (gal/d) 0.003785 cubic meter per day (m3/d)

million gallons per day (Mgal/d) 0.04381 cubic meter per second (m3/s)

million gallons per day per square mile 

[(Mgal/d)/mi2]

1,461 cubic meter per day per square kilometer [(m3

/d)/km2]

inch per year (in/yr) 25.4 millimeter per year (mm/yr)

Radioactivity

picocurie per liter (pCi/L) 0.037 becquerel per liter (Bq/L) 

Specific capacity

gallon per minute per foot [(gal/min)/ft)] 0.2070 liter per second per meter [(L/s)/m]

Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit (°F) as follows:

°F = (1.8×°C)+32

Temperature in degrees Fahrenheit (°F) may be converted to degrees Celsius (°C) as follows:

°C = (°F-32)/1.8

Vertical coordinate information is referenced to the North American Vertical Datum of 1988 

(NAVD 88).

Vertical coordinate information is referenced to the National Geodetic Vertical Datum of 1923 

(NGVD 23).

Horizontal coordinate information is referenced to the North American Datum of 1983 (NAD 83).
vii

List of Acronyms

CFC Chlorofluorocarbons

CRN Climate Response Network

CSI Community Science Institute 

HYSEP Hydrograph-separation computer program 

MCL Maximum contaminant level 

NWIS National Water Information System 

NWQL National Water Quality Laboratory

NYSDOH New York State Department of Health

SMCL Secondary maximum contaminant level 

TM Tompkins

TU Tritium unit

USEPA U.S. Environmental Protection Agency 

USGS U.S. Geological Survey
This page has been left blank intentionally.
Geohydrology and Water Quality of the Valley-Fill Aquifer 

System in the Upper Sixmile Creek and West Branch 

Owego Creek Valleys in the Town of Caroline, Tompkins 

County, New York

By Todd S. Miller

withdrawn from pumped wells is returned to the groundwater 

system via septic systems.

Groundwater in the upper and basal confined aquifers in 

the upper Sixmile Creek valley is under artesian conditions 

everywhere except where the water discharges to springs 

along bluffs in the western end of the Sixmile Creek valley. 

Principal sources of recharge to the confined aquifers are 

(1) the sides of the valley where the confined aquifers may 

extend up along the flank of the bedrock valley wall and crop 

out at land surface or are overlain and in contact with surficial 

coarse-grained deltaic and fluvial sediments that provide 

a pathway through which direct precipitation and seepage 

losses from tributary streams can reach the buried aquifers, or 

(2) where the buried aquifers are isolated and receive recharge 

only from adjacent fine-grained sediment and bedrock.

The base-flow and runoff components of total streamflow 

at two streamgages, Sixmile Creek at Brooktondale and 

Sixmile Creek at Bethel Grove, were calculated using 

hydrograph-separation techniques from 2003 to 2007 

discharge records. Base flow constituted 64 and 56 percent of 

the total annual flow at the Brooktondale and Bethel Grove 

streamgages, respectively.

Water-quality samples were collected from 2003 to 2005, 

with 10 surface-water samples collected seasonally during 

base-flow conditions at the Sixmile Creek at Brooktondale 

streamgage, and 12 samples were collected during base-flow 

conditions at several selected tributaries from 2004 to 2005. 

The predominant cation detected in the surface-water samples 

was calcium, but moderate amounts of magnesium, silica, and 

sodium were also detected; the major anions were bicarbonate, 

chloride, and sulfate. Sodium and chloride concentrations 

were relatively low in all samples but increased downstream 

from the Sixmile Creek sampling site at Six Hundred Road 

near Slaterville Springs, NY, to Brooktondale, NY; some of the 

increases may be attributed to road salt, but most are probably 

natural discharge of brackish water originating from deep 

zones in the bedrock that discharge upward into the valleyfill aquifer. The concentration of nitrate was less than 1.0 

milligram per liter (mg/L) in all stream samples taken during 

Abstract

In 2002, the U.S. Geological Survey, in cooperation 

with the Town of Caroline and Tompkins County Planning 

Department, began a study of the valley-fill aquifer system in 

upper Sixmile Creek and headwaters of West Branch Owego 

Creek valleys in the Town of Caroline, NY. The purpose of 

the study is to provide geohydrologic data to county and town 

planners as they develop a strategy to manage and protect 

their water resources. The first aquifer reach investigated in 

this series is in the Town of Caroline and includes the upper 

Sixmile Creek valley and part of West Branch Owego Creek 

valley. The portions of the valley-fill aquifer system that are 

comprised of saturated coarse-grained sediments including 

medium to coarse sand and sandy gravel form the major 

aquifers. Confined sand and gravel units form the major 

aquifers in the western and central portions of the upper 

Sixmile Creek valley, and an unconfined sand and gravel 

unit forms the major aquifer in the eastern portion of the 

upper Sixmile Creek valley and in the headwaters of the West 

Branch Owego Creek valley.

The valley-fill deposits are thinnest near the edges of the 

valley where they pinch out along the till-mantled bedrock 

valley walls. The thickness of the valley fill in the deepest part 

of the valley, at the western end of the study area, is about 

100 feet (ft); the thickness is greater than 165 ft on top of the 

Valley Heads Moraine in the central part of the valley.

An estimated 750 people live over and rely on 

groundwater from the valley-fill aquifers in upper Sixmile 

Creek and West Branch Owego Creek valleys. Most 

groundwater withdrawn from the valley-fill aquifers is 

pumped from wells with open-ended 6-inch diameter casings; 

the remaining withdrawals are from shallow dug wells or 

cisterns that collect groundwater that discharges to springs 

(especially in the Brooktondale area). The valley-fill aquifers 

are the sources of water for about 200 households, several 

apartment complexes, two mobile home parks, a school, and 

several farms and small businesses. Most groundwater that is 
2 Geohydrology & Water Quality of the Valley-Fill Aquifer System in the Town of Caroline, Tompkins County, New York

base-flow periods except in the tributary to Sixmile Creek at 

Slaterville Springs on July 19, 2005, when the concentration 

was 1.91 mg/L. Flow in this tributary during the summer 

originates from groundwater discharging from Valley Heads 

Moraine, which has large areas used for agriculture.

Groundwater samples were collected from 10 wells—9 

finished in sand and gravel aquifers and 1 finished in bedrock. 

Results of the groundwater sample analyses indicate the 

water is generally of good quality. Water in the sand and 

gravel aquifers is predominantly of the calcium-bicarbonate 

type. The cation detected in the highest concentrations was 

calcium; values ranged from 25.8 to 80.1 mg/L. Sodium 

values ranged from 2.6 to 106 mg/L; two samples exceeded 

the U.S. Environmental Protection Agency Drinking Water 

Advisory (30 to 60 mg/L) for sodium. Variations in sodium 

concentrations were probably due to either local enrichment 

through road de-icing salts or brackish water from bedrock 

that locally discharges to the valley. Nitrate concentrations 

in five of nine samples collected from the valley-fill aquifer 

were below the detection limit of 0.060 mg/L; concentrations 

ranged from 0.239 to 2.68 mg/L in the four wells that had 

concentrations above the detection limit. 

Three groundwater samples were collected and analyzed 

for chlorofluorocarbons (CFCs) and 3H to determine 

groundwater age. The results of the CFC and 3H samples 

indicated that the apparent age of the water from the flowing 

well at the Caroline Town Hall was early to late 1950s; in 

the shallow test well (39 ft deep) at the Caroline Elementary 

School, early-to-late 1970s; and from the deep test well 

(TM1967) at the school, early-to-late 1950s.

The reported yields by water-well drillers were greater 

for the unconfined sand and gravel aquifer—a median of 

15 gallons per minute—than for the confined aquifers—a 

median of 12 gallons per minute. Bedrock wells generally had 

smaller yields (median 6 gallons per minute) than the valleyfill aquifers. The mean well depths for the various aquifer 

types were: 42 ft for the unconfined sand and gravel aquifer, 

64 ft for the confined sand and gravel aquifers, and 149 ft for 

bedrock aquifers.

Introduction

In 2002, the U.S. Geological Survey (USGS), in 

cooperation with the Tompkins County Planning Department, 

began a series of studies of the valley-fill aquifer in Tompkins 

County in order to provide geohydrologic data to county 

and town planners as they develop a strategy to manage 

and protect their water resources. A reconnaissance-level 

USGS aquifer map report “Unconsolidated Aquifers in 

Tompkins County, New York” (Miller, 2000) was used as a 

guide to delineate 17 reaches of valley-fill aquifers (fig. 1) 

to investigate in more detail during approximately the next 

20 years. The extents of the reaches were based mostly on 

natural hydrologic boundaries, but in some cases political 

boundaries were also considered. Reach lengths were limited 

to about 3 to 10 mi each to be logistically manageable. In 

2002, the USGS, in cooperation with the Town of Caroline 

and the Tompkins County Planning Department, began a 

study of the valley-fill aquifer in upper Sixmile Creek and 

the headwaters of West Branch Owego Creek valleys in the 

Town of Caroline (fig. 1). Where a reach of valley-fill deposits 

contains multiple aquifers, that reach is defined as an aquifer 

system, but not all reaches have more than one aquifer.

Tompkins County lies within the northern area of 

the Appalachian Plateau in central New York (fig. 2). The 

northern part of the county is within the extensively glacially 

eroded Finger Lakes region, with rounded hills of low to 

moderate relief; the southern part of the county lies within 

the Appalachian Plateau of moderately high relief (fig. 2). 

The valley-fill aquifer in the upper Sixmile Creek and West 

Branch Owego Creek valley described in this report is in the 

Appalachian Plateau region (figs. 1 and 2).

The study area for this report includes confined and 

unconfined aquifers in the upper Sixmile Creek basin and 

the adjacent West Branch Owego Creek basin to the east 

(fig. 3). In this report, “Sixmile Creek basin” refers to the 

entire watershed that drains to Sixmile Creek; “Sixmile Creek 

valley” and “West Branch Owego Creek valley” refer to the 

relatively flat, low-lying valley floors and underlying valleyfill deposits that are beneath the main channel of Sixmile 

Creek and adjacent headwaters of the West Branch Owego 

Creek valleys.

The geologic history of Sixmile Creek basin and the 

headwaters of West Branch Owego Creek basin (discussed in 

more detail in the Geology section of this report) has resulted 

in the creation of two distinct hydrophysiographic settings, 

which enabled the division of Sixmile Creek valley into two 

areas—upper Sixmile Creek valley, including the headwaters 

of West Branch Owego Creek valley, and lower Sixmile 

Creek valley, including the headwaters of Willseyville Creek 

(figs. 1 and 3). Upper Sixmile Creek valley and the headwaters 

of West Branch Owego Creek valley are higher in altitude and 

have undergone less erosion by ice than lower Sixmile Creek 

valley. The depositional environment of the upper deposits in 

upper Sixmile Creek valley was dominated by glaciofluvial 

meltwater and post-glacial fluvial processes, whereas in the 

lower Sixmile Creek valley, the upper portion of the valley fill 

was dominated by subglacial processes (deposition of till).

Purpose and Scope

The Town of Caroline and Tompkins County need 

geohydrologic data regarding the major valley-fill aquifers 

within the town to develop a strategy to manage and protect 

their water resources. Interest in the interaction between 

groundwater and surface water has increased in recent 

years due to widespread concerns related to water supply 

and water quality. This report describes the geohydrology 

of the valley-fill aquifer system in the upper Sixmile Creek 
Introduction 3

EXPLANATION

Aquifer reach names

Cascadilla Creek valley and upland Sixmile Creek valley

Enfield Creek valley

Lower Cayuga Inlet valley

Lower Fall Creek valley

Lower Sixmile Creek valley (Towns of Dryden and Ithaca)

Owasco Inlet valley

Pony Hollow valley

Salmon Creek/Myers Point/Locke Creek

Taughannock Creek valley and delta

Upper Buttermilk Creek and Danby Creek valleys

Upper Cayuga Inlet valley

Upper Fall Creek valley

Upper Sixmile Creek and West Branch Owego Creek valleys

(subject of this study)

Virgil Creek valley

West Branch Cayuga Inlet and Fish Kill valleys

West Branch Owego Creek valley and tributaries

Lower Sixmile Creek and Willseyville Creek valleys

(Town of Caroline)

0 2 4 MILES

0 2 4 KILOMETERS

76°40' 76°30' 76°20'

42°30'

42°20'

Base map created with TOPO!, scale 1:100,000

2003 National Geographic (www.nationalgeographic.com/topo)

Aquifers mapped by Miller (2000)

TOWN OF 

LANSING

TOWN OF 

GROTON

TOWN OF 

ULYSESSES

TOWN OF 

ENFIELD

TOWN OF 

ITHACA

CITY OF 

ITHACA

TOWN OF 

DRYDEN

TOWN OF 

CAROLINE

TOWN OF 

DANBY

TOWN OF 

NEWFIELD

CAYUGA COUNTY

TOMPKINS

COUNTY

TOMPKINS COUNTY

CORTLAND COUNTY

TOMPKINS COUNTY

TIOGA COUNTY

TOMPKINS COUNTY

CHEMUNG

COUNTY

SCHUYLER

COUNTY

TOMPKINS COUNTY

SENECA COUNTY

CAYUGA LAKE

Figure 1. Location of 17 unconsolidated aquifer reaches in Tompkins County, New York.
4 Geohydrology & Water Quality of the Valley-Fill Aquifer System in the Town of Caroline, Tompkins County, New York

and the headwaters of West Branch Owego Creek valleys, 

including (1) the geologic geometry; (2) the groundwater 

flow system, including water levels, groundwater and 

surface-water interaction, recharge and discharge conditions; 

(3) water quality, including concentrations of common ions 

and nutrients; and (4) groundwater age. To aid in these 

descriptions, the following are being included in this report: 

(1) geohydrologic sections; (2) maps and diagrams depicting 

well locations, geology, groundwater levels, and the direction 

of groundwater flow; and (3) tables of well records and waterquality data. 

Description of Study Area

The study area is on the northern rim of the Appalachian 

Plateau (fig. 2) where, over millions of years, formerly 

southward-draining streams have been pirated by advancing 

southward-incising streams, which have courses that presently 

drain northward into the Great Lakes. The study area extends 

eastward 4.1 miles from Brooktondale, NY, along the Sixmile 

Creek valley to the surface-water divide between Sixmile 

Creek and West Branch Owego Creek (about 1.6 mi east of 

Slaterville Springs, NY) and 2.5 mi eastward into the West 

Branch Owego Creek valley from the surface-water divide 

(figs. 3 and 4). Overall, the valley-fill aquifer is 6.6 mi in 

length, averages 0.6 mi in width, and has a surface area of 

4.7 mi2. Range in altitude between hilltops and the valley floor 

varies from 300 to 1,000 ft, with hilltop altitudes generally less 

than 2,000 ft above NGVD29. Hilltops are slightly higher in 

the southern and eastern parts of the study area (ranging from 

1,700 to 2,000 ft in altitude) than in the western part of the 

study area (ranging from 1,500 to 1,700 ft in altitude, fig. 4).

25 50 75 100 MILES

0 25 50 75 100 KILOMETERS

0

LAKE ONTARIO

NEW HAMPSHIRE

Modified from Cressey (1966, fig. 9)

CANADA

Mohawk Lowlands

Hudson Lowlands

Tug

 Hill

 Plateau

Adirondack

Mountains 

New England Uplands

Atlantic Coastal Plain

Triassic Lowland

NEW

JERSEY ATLANTIC OCEAN

CONNECTICUT

MASSACHUSETTS

Erie 

Lowlands

Ontario Lowlands

CANADA

PENNSYLVANIA

NEW YORK

VERMONT

Appalachian Plateau

Appalachian Plateau

Finger Lakes and hills

of the Appalachian

Plateau 

(severely 

eroded)

LAKE ERIE

Study area

Tompkins

County

45°

80° 78° 76° 74° 72°

44°

43°

42°

41°

St. Lawrence-Champlain Lowlands

Base from U.S. Geological Survey digital data, 1972, 1:2,000,000

Albers Equal-Area Conic projection

Standard parallels 20°30' and 45°30', central meridian -96°00'

Figure 2. Physiographic features and location of upper Sixmile Creek valley and West Branch Owego Creek valley study 

area in Tompkins County, New York.
Introduction 5

Tompkins 

County

NEW

YORK

Area

shown in 

this figure

00

5 MILES

5 KILOMETERS

TOWN OF ITHACA

TOWN OF DANBY

TOWN OF ITHACA

TOWN OF DRYDEN

Lower

Sixmile

Creek/Willseyville trough valley Lower Sixmile Creek basin

Lower Sixmile 

Creek basin

Upper Sixmile Creek basin

CAYUGA

Upper Sixmile Creek basin

TOWN OF DRYDEN

TOWN OF CAROLINE

TOWN OF CAROLINE

TOWN OF DANBY

West Branch Owego 

Creek basin

TOMPKINS COUNTY

TIOGA COUNTY

West Branch Owego 

Creek basin

04233300

Sixmile Creek at 

Bethel Grove 

streamgage

04233286

Sixmile Creek at

Brooktondale

streamgage

IthacaReservoir

Siltdam

Upper

Sixmile

Creek

W/ est B

ranch Owego Creek

valley-fill aquifer

76°20' 76°25' 76°30'

42°25'42°20'

Base from National Geographic, 1:100,000 Topographic, Shaded-Relief Map

Figure 3. Location of lower Sixmile Creek basin, and the valley-fill aquifer extending across the upper Sixmile Creek basin and in the headwaters of West Branch Owego Creek basin, Town of Caroline, New York.
6 Geohydrology & Water Quality of the Valley-Fill Aquifer System in the Town of Caroline, Tompkins County, New York

Sixmile

Creek

Willow

Creek

West Branch Owego

Creek 79

330

79

Harford-Slaterville Road

79

Landon

Road

Ellis Hollow Road

Valley Road

Aquifer Boundary

TOWN OF DRYDEN

TOWN OF CAROLINE

TOWN OF RICHLAND

TIOGA COUNTY

TOWN OF CAROLINE

TOMPKINS COUNTY

TOWN OF DRYDEN

TOWN OF CAROLINE

Brooktondale

Slaterville 

Springs

Caroline

0 1 MILE 0.5

0 1 KILOMETER 0.5

Base from U.S. Geological Survey, Seamless Data Distribution System,accessed in 2007 at http://seamless.usgs.gov, Universal Transverse Mercator projection, Zone 18

Sixmile Creek basin

(Lake Ontario basin)

West Branch Owego Creek basin (Susquehanna River basin)

Through valley

Drainage Divide Altitude (feet) 2,000 1,500

1,300

1,100

860

Datum is NAVD1988

TOWN OF DRYDEN

TOWN OF LANSING

TOWN OF DANBY

TOWN OF NEWFIELD TOWN OF CAROLINE

TOWN OF GROTON

TOWN OF ITHACA

TOWN OF 

ENFIELD

TOWN OF ULYSSES

CITY OF 

ITHACA

Area shown

on map

TOMPKINS

COUNTY

76°17' 76°24'

42°25'42°22'

Figure 4. Shaded relief and boundary of valley-fill aquifer in the upper Sixmile Creek valley and the headwaters of West Branch Owego Creek valley, Town of Caroline, New York.
Data Collection 7

Previous Studies

In 1988, the USGS conducted an investigation of 17 

headwater valleys in upstate New York (Randall and others, 

1988); the headwaters of West Branch Owego Creek valley in 

the Town of Caroline (in the eastern part of this investigation) 

was one of the areas studied. The study included a well 

inventory and a brief evaluation of the geology and hydrology 

of the valley-fill aquifer.

Additional well records were collected by Miller (2000) 

for a general countywide aquifer study of Tompkins County. 

The results of this study were used to produce a map report, 

which delineates the extent of unconsolidated aquifers in 

Tompkins County.

Reconnaissance surficial geologic mapping at the scale of 

1:24,000 of the headwaters of West Branch Owego Creek was 

done by Waller in 1982 (in Randall and others, 1988). Surficial 

geology also was mapped at the scale of 1:250,000 by Muller 

and Cadwell (1986) for a statewide mapping effort and was 

a reconnaissance study. Little geologic mapping has been 

conducted in upper Sixmile Creek valley and no subsurface 

stratigraphy has been investigated. Soils data were mapped at 

a scale of 1:20,000 (Neeley, 1961).

Data Collection

The USGS collected the following types of information 

for inclusion in this report: geologic data, seismic-refraction 

surveys, well stratigraphic records collected through well 

inventory and test drilling, water-level and streamflow 

measurements, and water-quality data of surface water 

and groundwater.

Geologic Data

Geologic data were collected by use of seismic-refraction 

surveys, field reconnaissance, interpretation of topographic 

maps and orthophotos, and review of available geologic 

reports, soil maps, and well-drilling records. 

Seismic-Refraction Surveys

The seismic-refraction survey method uses refracted 

compressional waves of seismic energy and is based on the 

time for energy generated at a point, such as a small explosive 

charge, to travel through the ground to receivers (geophones). 

The velocity of sound traveling through unsaturated 

unconsolidated deposits, saturated unconsolidated deposits, 

and bedrock can be calculated, and this velocity is used to 

predict the depth to bedrock. Seismic-refraction techniques 

used in this study are described by Haeni (1988). Seismicrefraction surveys were conducted at three sites to supplement 

data from test drilling. 

From 2003 to 2005, seismic-refraction data were 

collected at three sites by using a 12-channel signalenhancement seismograph. A series of 12 geophones spaced 

either 50 or 100 ft apart were inserted into the ground, and 

arrival times of compressional waves generated by explosives 

buried 4 to 5 ft below land surface were recorded and plotted 

as a function of “source-to-geophone” distances. In the seismic 

lines where the water table was relatively shallow (generally 

less than 5 ft below land surface), the unsaturated zone was 

considered too thin to include as a layer and was ignored, 

and a two-layer (saturated unconsolidated sediments and top 

of bedrock) boundary-formula computer analysis (Scott and 

others, 1972) was used to calculate depths to bedrock. In the 

seismic line where the unsaturated zone was 10 to 20 ft thick 

or more, a three-layer (saturated unconsolidated sediments and 

top of bedrock) boundary-formula computer analysis (Scott 

and others, 1972) was used to calculate depths to water table 

and to bedrock.

Well Inventory, Test Drilling, Groundwater-Level 

and Streamflow Measurements

Seventy-eight well records were collected and compiled 

in this report (Appendix 1). Forty-eight well records were 

obtained from water-well drillers’ reports that were submitted 

during the years 2000–07 to the New York State Department 

of Environmental Conservation Water Well Completion 

Report program. Data from the well drillers’ reports include: 

lithologic logs, water levels, estimated well yields, and well 

construction information (well and casing depths, casing 

diameter, and length of casing sticking up above land surface). 

The well inventory was augmented by test drilling at two 

sites using air-rotary drilling methods in which 6-in. diameter, 

steel-cased observation wells were installed to obtain data 

on stratigraphy and water levels in the aquifers. The casings 

were perforated where substantial water-bearing zones were 

penetrated in the valley-fill deposits. All records collected 

for this study were entered into the USGS Groundwater 

Site Inventory computer data base and are accessible at 

http://waterdata.usgs.gov/ny/nwis/inventory. 

Levels were run to about half of the wells from the 

drillers’ logs to determine the altitudes of the water-levelmeasuring points, which typically coincide with the top of the 

well casing. The altitudes of land surface and measuring points 

of the remaining wells were estimated from USGS 1:24000 

scale topographic contour maps. When possible, depth to 

water in wells was measured using an electric tape. Where 

measured, depths were converted to altitudes, plotted on a 

map, and contoured to depict the water table in unconfined 

aquifers and potentiometric surfaces in the confined aquifers. 

Levels were also run to the streamgage at Brooktondale 

(04233286); all altitudes were determined using standard 

surveying methods (Kennedy, 1990) and are generally 

accurate to within 0.01 ft. Streamflow was measured using a 

current meter in several reaches of Sixmile Creek and tributary 
8 Geohydrology & Water Quality of the Valley-Fill Aquifer System in the Town of Caroline, Tompkins County, New York

streams during collection of stream water-quality samples 

during the years 2003–05. Streamflow measuring techniques 

are described by Buchanan and Somers (1982).

Water-Quality Sampling and Analysis

For this investigation, groundwater samples were 

collected from 10 wells from 2004 to 2005. Ten surface-water 

samples were collected seasonally during base-flow conditions 

at Sixmile Creek at Brooktondale streamgage (04233286) 

from 2003 to 2005, and 13 samples were collected during 

base-flow conditions at several selected tributaries to Sixmile 

Creek and West Branch Owego Creek from 2004 to 2005. The 

samples for inorganic constituents and nutrients were analyzed 

by the USGS National Water Quality Laboratory (NWQL) 

in Denver, Co. and field measurements of pH, specific 

conductance, and water temperature were taken. The samples 

were collected using the equal-width-increment method and 

processed following methods described in the USGS National 

Field Manual for the Collection of Water-Quality Data (U.S. 

Geological Survey, variously dated). 

Nine groundwater samples were collected from wells 

completed in sand and gravel aquifers, and one was collected 

from a well finished in bedrock. In the seven sampled 

domestic wells that had pumps, samples were collected by 

first turning the well pump on and allowing it to run for about 

20 minutes or until at least five casing-volumes of well water 

had been purged from the casing. A raw-water spigot between 

the well and the pressure tank was then opened, and the water 

was allowed to run for several more minutes to flush the line 

to the spigot. Samples were then collected from the raw-water 

spigot to bypass all water-treatment systems and ensure that 

the samples collected were representative of the water in 

the aquifer. In the three test wells completed for this study, a 

stainless-steel submersible pump was used to purge 5 to 10 

casing-volumes of water from the well before collecting 

water samples.

Three groundwater samples also were collected and 

analyzed for chlorofluorocarbons (CFCs) and the 3H isotope 

to determine the recharge age of the water—the date when it 

first entered the saturated groundwater system. 3H samples 

were analyzed at the USGS Isotope Geochemistry Laboratory 

in Menlo Park, Calif. The method of preparing the 3H sample 

is described by Ostlund and Werner (1962) and the analysis 

method is described by Thatcher and others (1977). CFC 

samples were collected according to sampling methods 

that minimize atmospheric exposure (U.S. Geological 

Survey, variously dated) and were analyzed at the USGS 

Chlorofluorocarbon Laboratory in Reston, Va. Concentrations 

of CFC–12, CFC–11, and CFC–113 were measured by purgeand-trap gas chromatography and an electron-capture detector 

(Busenberg and Plummer, 1992). Age-dating of groundwater 

using this method gives an approximate time since the water 

recharged the aquifer (from precipitation) and entered the 

saturated zone, essentially fixing the CFC concentrations by 

cutting off their interaction with the atmosphere. Ages are 

determined by matching the concentrations of the tracers 

in groundwater to historical atmospheric concentrations of 

these tracers. Details of CFC and 3H dating are explained in 

Plummer and others (1993) and Reilly and others (1994).

 In the three wells where CFC samples were collected, 

samples were also collected and analyzed for concentrations 

of dissolved gases (argon, methane, carbon dioxide, 

nitrogen, and oxygen) and excess air. The results of these gas 

analyses were used to estimate recharge temperatures and to 

reconstruct initial nitrate concentrations based on the amount 

of denitrification that has occurred. Recharge temperature 

and excess air of recharge water are important components in 

interpreting the age of the water, along with concentrations 

of CFCs (Heaton, 1981; Heaton and Vogel, 1981; Stute and 

Schlosser, 1999). 

Geology

The Northeastern United States was repeatedly covered 

by continental ice sheets during the past 2.5 million years 

(Teller, 1987). The chronology of glaciation and deglaciation 

in eastern North America is long and complex with many 

episodes of global cooling over the past 2.5 million years. 

The ice deepened some valleys, transported vast quantities 

of sediment, and deposited the sediment upon the scoured 

bedrock as a mantle of glacial drift. Each ice sheet eroded 

previously deposited unconsolidated sediments and bedrock 

and eventually redeposited the debris as a widespread but 

highly variable mantle of glacial drift. The most recent 

glaciation, referred to as the Wisconsinan episode, reached its 

maximum extent in most of northeastern North America about 

21,000 years ago (Mickelson and others, 1983; Stone, 1995). 

The most recent deglaciation in New York was interrupted 

by several readvances and retreats. Some of these readvances 

and retreats were of a regional extent that reflected changes 

in climate, and others had more of a local extent that could 

be attributed to ice dynamics and the interaction of ice sheets 

with proglacial lakes (Randall, 2001).

Upper Sixmile Creek and West Branch Owego Creek 

valleys are in the northern perimeter of the Appalachian 

Plateau (fig. 2); the eastern part of the valley is near a former 

bedrock saddle that once crossed the valley and formed a 

preglacial drainage divide. The former saddle was enlarged 

and deepened by glacial erosion that conveyed large volumes 

of meltwater and sediment. It is likely that the former saddle 

was either removed or shifted in position as a result of 

glacial erosion—in the Finger Lakes region this feature is 

termed a “through valley” (fig. 4). Tarr (1905) described it 

as follows: “Along a number of valleys it is possible to pass 

from one drainage system to the other through open valleys in 

which the present divides are determined not by rock, but by 

drift deposits.” 
Geology 9

Geologic materials in upper Sixmile Creek basin 

include bedrock, till, and stratified drift (fig. 5). Bedrock 

underlies the entire region but is mantled nearly everywhere 

by unconsolidated glacial drift that includes till or stratified 

drift deposits (fig. 5). Bedrock consists of Devonian shale 

and siltstone. Till is an unsorted, unstratified mixture of clay, 

silt, sand, gravel, and rocks deposited directly by glacial ice, 

rather than by meltwater. The larger gravel and rock, which 

are typically embedded in a fine-grained matrix consisting 

of clay, silt, and very fine sand, range in size from pebbles to 

boulders and typically are present directly overlying bedrock 

but also may be interbedded within the valley-fill drift in 

upper Sixmile Creek valley. Till has low permeability (low 

hydraulic conductivity) because it is poorly sorted material 

within a fine-grained matrix that was greatly compacted by the 

weight of the ice. Stratified drift, the end product of sediment 

deposition by glacial meltwater, is typically present in the 

major valleys and consists of layered, sorted glaciofluvial and 

glaciolacustrine sediments that were deposited in lowlands as 

the ice sheets retreated. When meltwaters flowed into these 

lakes, deltaic sands and gravel were deposited in near-shore 

environments, while further from shore, in the deeper parts 

of lakes, fine-grained (silt and clay) lake-bottom deposits 

accumulated. When the lake filled up with sediment or the lake 

drained, meltwaters deposited deltaic topset and fluvial sand 

and gravel on top of the deltaic deposits. The stratified drift 

comprised of sand and gravel forms the productive valleyfill aquifers in the study area. These aquifers are capable 

of supplying well yields more than an order of magnitude 

larger than are generally obtainable from the underlying 

shale bedrock.

Bedrock Scouring

Preglacial valleys that were oriented along the primary 

direction of ice movement, such as those valleys presently 

occupied by Cayuga Lake and lower Sixmile Creek valley 

(fig. 1), were extensively widened and deepened by flowing 

ice and subglacial meltwater. Erosion by ice had truncated 

bedrock hillsides (spurs), which resulted in creation of 

nearly straight, U-shaped bedrock troughs. Bedrock troughs 

in central New York are common along the northern rim 

of the Appalachian Plateau; many of these troughs are 

now contained in the Finger Lakes region. Clayton (1965) 

referred to the Finger Lake valleys as “intrusive troughs” 

that were carved when ice that flowed south from the Lake 

Ontario Plain encountered a landmass of higher altitude, in 

this case the Appalachian Plateau, and flowed uphill, against 

the regional slope. Bedrock troughs are often referred to as 

having U-shaped profiles although many are asymmetrical, 

with one valley wall steeper than the other. However, the more 

southward valleys and troughs intrude into the Appalachian 

Plateau (fig. 2), the width of valleys decreases, and the valley 

profiles transition from broad U-shaped to narrow U-shaped to 

V-shaped profiles.

East-west trending valleys that are tributaries to deep 

troughs, such as upper Sixmile Creek valley (figs. 1 and 3), 

were not oriented parallel to the direction of ice movement 

and underwent less intensive scouring, which resulted in less 

erosion than in north-south trending valleys. These east-west 

trending tributary valleys end high above the floor of the 

troughs they join and are known as “hanging valleys.” The 

differing orientations of lower Sixmile Creek valley (roughly 

north-to-south) (fig. 1) and that of upper Sixmile Creek and 

West Branch Owego Creek valleys (east-to-west) facilitated 

the division of the basin into two parts, each with distinct 

geologic features and hydrologic conditions. 

Wisconsinan Drift

The glacial history of the late Wisconsinan ice sheet in 

central New York was an unsteady process, marked by pauses 

and temporary readvances that complicate the stratigraphic 

record in the study area. Most of the unconsolidated sediments 

in this study area were probably deposited during the late 

periods of deglaciation of the late Wisconsinan. There was 

more meltwater available during this period due to a warmer 

climate than during preceding colder periods when the ice was 

advancing and primarily erosion was taking place.

All large northward-draining valleys along the northern 

rim of the Appalachian Plateau contain unconsolidated 

deposits up to several hundred feet thick. In general, the bulk 

of the valley fill consists of layers of tills and fine-grained 

lake deposits. Northward-draining valleys, such as the lower 

Sixmile Creek valley, favor deposition of mostly fine-grained 

sediment because proglacial lakes formed between the ice 

front to the north and the major surface-water divide to the 

south. The ice tended to melt and retreat relatively quickly 

because it was in contact with the lake, so there was relatively 

little time for meltwaters to deposit coarse-grained material. 

Although coarse-grained sediment (sand and gravel) is usually 

a minor component of the valley fill in north-draining valleys, 

locally, several tens of feet of sand and gravel accumulated in 

the study area and east of the Valley Heads Moraine, and at the 

delta near Brooktondale (fig. 5). 

In central New York, the Valley Heads Moraine was 

deposited where the ice-margin paused as it retreated 

northward within the major valleys of the Finger Lakes region, 

including upper and lower Sixmile Creek valleys. The Valley 

Heads Moraine is defined by massive, hummocky deposits of 

coarse-grained, heterogeneous stratified drift that fill the valley 

from side to side. These deposits range in length from about 

1,000 ft to about 2 mi and have been termed “valley-choker 

moraines” (MacClintock and Apfel, 1944) and “valley plugs” 

(Cadwell, 1972). In Sixmile Creek basin, the ice that formed 

the Valley Heads Moraine flowed south in the lower Sixmile 

Creek trough and, at near present day Brooktondale, a tongue 

of ice branched off and flowed eastward several miles. The 

extent of ice in the uplands of the upper Sixmile Creek basin 

is uncertain, however. When the ice front retreated in upper 
10 Geohydrology & Water Quality of the Valley-Fill Aquifer System in the Town of Caroline, Tompkins County, New York Base from U.S. Geological Survey, Seamless Data Distribution System, accessed in 2007 at http://seamless.usgs.gov Universal Transverse Mercator projection, Zone 18 TOWN OF CAROLINE TOWN OF DRYDEN TOWN OF RICHLAND TOWN OF CAROLINE TIOGA COUNTY TOMPKINS COUNTY TOWN OF DRYDEN TOWN OF CAROLINE Brooktondale Slaterville Springs Caroline West Slaterville Valley Heads Moraine

0 1 MILE 0.50 1 KILOMETER 0.5

EXPLANATION

Alluvial flood-plain deposits (facies 3)—Silty sand and gravelThin alluvial flood-plain deposits (facies 3)over bedrockAlluvial fan deposits—Sand and gravelSwamp deposits—Peat and muckOutwash terrace deposits—Sand and gravelDelta deposits (facies 3)—Sand and gravelKames deposits (facies 1)—Sand and gravel

Shale and siltstone (Most of the uplandsconsist of a mantle of till over bedrock.Bedrock is at land surface in some places,especially on hilltops and steep hillsides

Outwash (facies 3)—Sand and gravelYoungest till from Valley Heads readvance

Till deposit overlying kame terracedeposits (sand and gravel)

Large bluffs exposed by extensive erosion. Probably several deposits are exposed butthey are too small to depict at this scaleAquifer boundary—Dotted line indicateswhere boundary is arbitrarily cut off 

Stratified drift

Unstratified drift

Unstratified drift (continued)Bedrock

WaterIce-marginal meltwater channel

Outletchannel

76°17' 76°24'

42°25'42°22'

Figure 5. Surficial geology of the valley-fill aquifer in upper Sixmile Creek valley and part of West Branch Owego Creek valley, Town of Caroline, New York.
Geology 11

Sixmile Creek valley, it melted back westward until it joined 

the ice in lower Sixmile Creek valley, which retreated to 

the north.

Valley-fill deposits are thickest in the middle of the valley 

and thinnest along the edges where bedrock and till crops out 

at land surface. The deposits in the thalweg (the deepest part 

of the valley) also thicken to the east. The thickness of the 

valley-fill deposits is about 100 ft at the west end of the study 

area. Data collected at a deep well (TM1979, fig. 6) drilled 

near the lip of the hanging valley at the west end of the study 

area indicate that the thickness of the valley fill is 104 ft. In 

the central part of the study area, two deep wells, TM1967 

and TM2028 (fig. 6), penetrated bedrock at depths of 160 and 

165 ft, respectively. The maximum thickness of the valley-fill 

drift is greater than 165 ft at the Valley Heads Moraine, where 

a deep test well (TM1968, fig. 6) was drilled to a depth of 

165 ft without encountering bedrock. No wells in the eastern 

part of the study area penetrated to bedrock in the central part 

of the valley, although the maximum well depth was 90 ft at 

well TM 56 (fig. 6). 

Depositional Facies 

According to Randall (2001), in nearly all valleys 

in the glaciated Northeastern United States, the stratified 

drift consists of three facies that reflect the depositional 

environment in which the sediments were laid down.

• Facies 1. Early deglacial, proximal, or ice-contact facies: 

predominantly coarse-grained, heterogeneous sediment, 

varying widely in degree of sorting; deposited close to 

active ice and (or) amid abundant stagnant ice masses. 

• Facies 2. Mid-deglacial, distal facies: predominantly finegrained sediment, deposited in moderately large bodies of 

water, farther from active ice than facies 1. 

• Facies 3. Late-deglacial or postglacial, surficial facies: 

coarse-grained sediment; commonly well-sorted; deposited 

in shallow water and commonly atop facies 2 or 1.

Where all three facies are present at one location, 

they form a characteristic, coarse over fine over coarse 

stratigraphy. At some locations, however, only one or two 

facies are present. Locally, the three-facies model can be an 

oversimplification of the true complexity of stratified-drift 

stratigraphy. Ice surges or readvances also result in local 

complexities. Despite local complexities and absences of 

individual facies, the three-depositional-facies stratigraphic 

concept is widely applicable throughout the glaciated 

Northeast (Fleisher, 1986; Miller and Randall, 1991; 

Randall, 1981).

Facies 1—Ice-Contact Deposits

Facies 1 contains large amounts of coarse-grained 

sediment (kame and outwash sand and gravel) transported 

tens of miles by subglacial streams in crevasses and tunnels 

beneath the ice or by ice-marginal streams that flowed beside 

stagnant ice at the ice margin. Many subglacial channels 

persisted throughout the later stages of glaciation and 

deposited sand or gravel atop bedrock near the retreating ice 

margin. These deposits became the basal sand and gravel 

aquifer in the study area. Much of the basal sand and gravel 

deposits was subsequently buried by fine-grained lacustrine 

and (or) till sediments (deposited as facies 2), which 

hydraulically confined the basal sand and gravel deposits and 

formed the confined aquifer in upper Sixmile Creek valley. 

Sediment that was transported by meltwater issuing 

directly from the ice, as well as by streams from bordering 

uplands that were uncovered by ice, each contributed 

substantially to the deposition of stratified drift, but the ratio 

of sediment derived from these two sources differs from place 

to place (Randall, 2001). The lithology of most pebbles in 

the valley-fill gravel are similar to the local bedrock (gray 

Devonian-age shale in the Sixmile Creek basin), although 

the source of gravel is likely from upland streams that 

transported the clasts when the hills had been uncovered by 

ice. Conversely, when the pebbles contain abundant erratics 

(rocks not present in the local area, such as limestones, red 

sandstones, and igneous and metamorphic rocks), it is likely 

that this gravel was transported from further north directly by 

ice or by subglacial meltwater.

When the ice front was in contact with a proglacial lake, 

much of the fine-grained sediment remained in suspension and 

was later deposited downvalley as facies 2. As the ice front 

retreated, the deposition of coarse facies l retreated with it. 

In some places, stagnant blocks of ice were left behind as the 

ice front retreated. Sediment partially or completely buried 

many of these ice blocks and as these ice blocks melted, kettle 

depressions resulted. Where the bottoms of kettle depressions 

are below the water table, kettle lakes, ponds, and bogs 

commonly form in them. 

Facies 2—Proglacial Lake Deposits 

Topographically low lakes were common during the 

advance and retreat of ice in valleys that were aligned in the 

direction of glacier flow (roughly north to south) such as the 

Finger Lake troughs and lower Sixmile Creek valley. Some 

of these valleys, which were intensively scoured by ice, were 

eroded below sea level (Mullins and Hinchey, 1989). Highlevel lakes sometimes developed in major headwater valleys, 

such as upper Sixmile Creek valley. As is present at most 

places where the Valley Heads Moraine had plugged valleys, 

there is an abandoned channel at the lowest point on the Valley 

Heads Moraine (Miller and others, 1998) where, initially, for a 

short duration (probably for several decades), a proglacial lake 

on the backside of the moraine drained via the outlet channel 

on the crest of the moraine.

Stratified fine-grained sediments consisting of fine sand, 

silt, and clay settled on the bottoms of proglacial lakes in distal 

areas from the ice front. In areas where subglacial meltwaters 

disgorged at the mouths of tunnels beneath the ice, subaquatic 
12 Geohydrology & Water Quality of the Valley-Fill Aquifer System in the Town of Caroline, Tompkins County, New York

Sixmile

Creek

Willow

Creek

West Branch Owego

Creek

TOWN OF DRYDEN

TOWN OF CAROLINE

TOWN OF RICHLAND

TOWN OF CAROLINE

TIOGA COUNTY

TOMPKINS COUNTY

TOWN OF CAROLINE

TOWN OF DRYDEN

Brooktondale

Caroline

0 1 MILE 0.50 1 KILOMETER 0.5

04233286

Base from U.S. Geological Survey, Seamless Data Distribution System, accessed in 2007 at http://seamless.usgs.gov Universal Transverse Mercator projection, Zone 18

TM 1979

EXPLANATION

Aquifer boundary—Dotted line indicateswhere boundary was arbitrarily cut off U.S. Geological Surveystreamgage and identifier

04233286

Seismic-refraction survey lineWell and well site nameTest-well siteSurface-water sampling site

—Site name is

assigned by U.S. Geological Survey.Well data are in Appendix 1 at end of report

TM 73

TM 81

TM 60 TM 5

TM 8

8

6

TM 80 TM 78

TM 77

TM 76

TM 74

TM 71

TM 57 TM 56

TM 69

TM 62 TM 61

TM 75

TM 63

TM 55

TM 53

TM2022

TM2344

TM1802

TM1369 TM1876

TM1708

TM2154 TM2302

TM2233

TM1655

TM2176

TM2368

TM1970

TM1925

TM1918

TM1989

TM 987

TM1838

TM 999

TM2101

TM2166

TM2129

TM2079

TM2071

TM2364

TM1021

TM2028

TM1029

TM 996 TM 994 TM1967

TM1979

TM2023

TM 995

TM1968

TM 988

TM 986

TM 989

TM 990

TM1763

TM1808

TM1572

TM1494

TM1228

TM1624

TM1613

TM1438

TM1643

TM1261

TM 982

TM 984

TM 983

TM1504 TM1645 TM1219

TM1252

76°17' 76°24'

42°25'42°22'

Figure 6. Well locations in the upper Sixmile Creek valley and West Branch Owego Creek valley, Town of Caroline, New York.
Hydrology of the Valley-Fill Aquifer System 13

fans accumulated. These deposits consisted of sand and gravel 

in proximal areas to the ice, grading into finer sediments such 

as sand and silt further from the mouth of the tunnel. Deltas 

formed where meltwater flowing on top of and adjacent to the 

ice entered these proglacial lakes. The subaquatic fans and 

deltas typically consist of pebbly sands where the meltwater 

streams enter the lake, but grade into finer sediment such as 

fine sand and silt, in more distal parts of the lake. In upper 

Sixmile Creek valley, subaquatic fans may form parts of the 

basal aquifer on top of bedrock.

Facies 3—Late- and Post-Glacial Deposits

Facies 3 consists of surficial sand and gravel deposited 

in shallow ponded water or along stream channels late in 

the deglaciation of the area, or even after the glaciers had 

completely disappeared. Facies 3 typically is found atop 

the finer-grained, facies 2 deposits but can overlie facies 1 

deposits as well; these deposits are commonly finer grained 

and better sorted than facies 1 deposits (Randall, 2001).

Examples of depositional environments where 

facies 3 deposits were laid down in the study area include 

(1) meltwaters that deposited extensive outwash (valley trains 

or outwash plains) in front (east) of the Valley Heads Moraine 

and into West Branch Owego Creek valley, (2) late-stage 

fluvial meltwater that eroded sediment in the upper part of 

the basin and deposited much of the sediment to form the 

topset beds of the delta west of Brooktondale, (3) modern 

post-glacial streams that aggraded alluvial sediments in lowlying areas on the valley floor, and (4) upland tributaries that 

deposited alluvial fans where the tributaries join the main 

valley (fig. 5).

The ratio of clay and silt to sand and gravel within the 

glacial drift varies as a function of bedrock lithology and the 

depositional environment (Randall, 2001). Sixmile Creek 

basin is underlain by relatively weak shale and siltstone, which 

readily separates into tiny fragments of constituent particles 

of clay, silt, and fine sand during erosion and transport by 

ice and meltwater. Many sand grains are tiny fragments of 

shale or siltstone. Conversely, erosion of coarsely crystalline 

metamorphic and igneous bedrock (for example, rocks 

that comprise the Adirondack Mountains and the Canadian 

shield north of Lake Ontario) tends to yield many hard, 

durable cobbles, pebbles, and medium-to-coarse sand-size 

mineral grains.

Valley Heads Readvance 

The upper Sixmile Creek valley and the lower Sixmile 

Creek trough valley were overridden by a readvance of the 

ice at the time of formation of the Valley Heads Moraine 

system about 15,500 years ago (Fullerton, 1980). Randall 

(2001) identified the proximity where the Valley Heads ice 

readvanced into the northern rim of the Appalachian Plateau—

one of the regions where multiple drift layers are widespread 

and hydrologically important. The upper Sixmile Creek valley 

lies within this area. In this study area, evidence for these 

local readvances are found in cutbanks in Sixmile Creek and 

includes the presence of disturbed sediments (mostly thrust 

faults and folds in the till) caused by ice overriding previously 

deposited glacial sediments. The ice was thin at and near 

the terminus of these readvances; therefore, the erosion of 

underlying deposits was less pronounced because the ice was 

unable to scour down to bedrock. Instead, the relatively thin 

ice overrode previously deposited sediments and then, as the 

ice retreated again, it deposited additional till, glaciofluvial, 

and glaciolacustrine deposits over those older deposits. 

Fleisher (1991) hypothesized that ice tongues could easily 

readvance as much as 12 mi across soft deformable sediments, 

such as fine-grained lake deposits. Because the ice did not 

completely remove older underlying sediments in the upper 

Sixmile Creek valley during the Valley Heads readvance, there 

is a complicated stack of two deglacial sequences in the valley.

Hydrology of the Valley-Fill 

Aquifer System

The upper Sixmile Creek and West Branch Owego 

Creek valley-fill aquifer system contain both confined and 

unconfined aquifers (figs. 7 and 8). Confining layers are made 

up of geologic material with low permeability (low hydraulic 

conductivity) that prevent groundwater from moving through 

rapidly. In this study area, the confining layers consist of 

clay and silt or till. An unconfined aquifer is composed of 

sediments of sufficient permeability that are able to store 

and yield usable amounts of water to wells. In an unconfined 

aquifer, the water table is at or near atmospheric pressure and 

is the upper boundary of the aquifer; this type of aquifer is 

bounded by a relatively impermeable unit at the base of the 

aquifer. A confined aquifer (also known as artesian aquifer) 

is composed of sediments of sufficient permeability that are 

able to store and yield usable amounts of water to wells, in 

which the aquifer is bounded between confining layers. In a 

confined aquifer, the potentiometric surface is always above 

the top of the geologic unit in which the water is stored and 

transmitted. When a confined aquifer is tapped by a well, 

water in the casing is forced up to its potentiometric altitude. If 

the hydraulic pressure in the confined aquifer is great enough, 

it may cause the water in the well to flow above land surface, 

in which case the well is referred to as a flowing-artesian well. 

The upper Sixmile Creek valley is a moderately deep 

valley with a bedrock floor that is at an altitude of about 

880 to 900 ft near Brooktondale and rises slightly eastward 

toward the drainage divide between Sixmile Creek and West 

Branch Owego Creek. The western and central parts of the 

valley fill are generally less than 200 ft thick and consist of 

predominantly fine-grained stratified drift (lacustrine very 

fine sand, silt, and clay) and till that are interlayered with two 

units of coarse-grained sand and gravel, which comprise the 

confined aquifers in that part of the study area (figs. 7 and 8). 
14 Geohydrology & Water Quality of the Valley-Fill Aquifer System in the Town of Caroline, Tompkins County, New York 76°17' 76°24' 42°25' 42°22' Base from U.S. Geological Survey, Seamless Data Distribution System, accessed in 2007 at http://seamless.usgs.gov Universal Transverse Mercator projection, Zone 18

No data

Willow Creek

0 1 MILE 0.50 1 KILOMETER 0.5

Sixmile

Creek

West Branch Owego

Creek EXPLANATION Area with predominantly confined aquifers

Valley Heads MoraineArea with mostly an unconfined aquifer that may be locally confined by a shallow clay layer or clay lenses;likely contains a basal, confined aquifer on top of bedrock

—Complex area with predominantly an unconfined aquifer. Deposits grade into finer sediments

Area with predominantly confined aquifers that also has a thin surficial layer of sand and gravel that may bethinly saturated or saturated during wet periods only(fine sand and silt) with depth and are interbedded with sand and gravel layers that form confined aquifersAquifer boundary—Dotted where arbitrarily cut offLine of sectionSprings

—Section shown in figure 8

Seismic-refraction line—Data from seismic survey were used in section A–A' in figure 8 and in section B–B' in figure 10B

TM196

A'

8

A

B'

B

Well and well site name from which stratigraphic data were used to construct geologic section A-A'

—

Site name is assigned by U.S. Geological Survey. 

TOWN OF CAROLINE

TOWN OF DRYDEN

TOWN OF RICHLAND

TOWN OF CAROLINE

TIOGA COUNTY

TOMPKINS COUNTY

TOWN OF CAROLINE

TOWN OF DRYDEN

Caroline

Slaterville

Springs Caroline

Elementary

School

Brooktondale

Valley Heads

Moraine

Outwash

Flatiron Road

West

Slaterville

TM 62

TM2023 TM1219

TM1968

TM2028

TM 986 TM 994

TM1967

TM1029 TM1979

A'

A

B'

B

Figure 7. Aquifer types in upper Sixmile Creek and West Branch Owego Creek valley, Town of Caroline, New York.
Hydrology of the Valley-Fill Aquifer System 15

1 2 3 4 5 6

MILES

Kettle

pond

TM1979 

 VanDemark Road TM1029

 Caroline Elementary School TM 994, TM1967 

 Fountain Manor TM2028

 Town Hall TM 986 

West Slaterville

Slaterville 

Springs

TM1968

TM2023

Flatiron Road TM 62 

900800

1,3001,2001,1001,000

700

Lower 

Sixmile

Creek 

valley

 Six Hundred Road TM1219 

West Branch Owego Creek basin

Confining unit

Confining unit

Mostly unconfined aquifer unit may be partly confined in places 

Confining unit

Basal confined aquifer

Upper Confined aquifer

Shale

Shale

Drainage divide

Sixmile Creek

basin

1950s

1970s 1950s

Undifferentiated

valley fill

Till interbedded with sand and gravel lenses?

VERTICAL EXAGGERATION X 14 (VERTICAL SCALE GREATLY EXAGGERATED)

VERTICAL DATUM IS NATIONAL GEODETIC VERTICAL DATUM OF 1929

Sand and gravel lenses

Springs

FEET

A A'

West East

BEND IN SECTION

BEND IN SECTION

Valley Heads Moraine

Extent of basal confined aquifer unknown in eastern part of study area

(depth unknown)

Thin unconfinedsand and gravel

TM 990 

TM1838 

TM1252 

?

0

EXPLANATION

Approximate potentiometric surface in the upper confined aquiferApproximate potentiometric surface in the basal confined aquiferApproximate water table in the unconfined aquifer in West Branch Owego Creek valley

1950s Apparent groundwater age—Age determined from chlorofluorocarbon isotopes and tritium samples collected in 2004−05 

TM1838 Well and well site name—Site name is assigned by the U.S. Geological Survey.

Figure 8. Geohydrologic units section A–A’ along the thalweg of the upper Sixmile Creek valley and West Branch Owego Creek valley, Town of Caroline, New York. Line of section and well locations are shown in figure 7.
16 Geohydrology & Water Quality of the Valley-Fill Aquifer System in the Town of Caroline, Tompkins County, New York

In the eastern part of the upper Sixmile Creek valley and in the 

headwaters of the West Branch Owego Creek valley, there is 

an unconfined aquifer as well as at least one confined aquifer 

unit that extend from the Valley Heads Moraine to the eastern 

boundary of the study area (figs. 7 and 8). 

Aquifer Geometry

Characterizing aquifer geometry requires (1) mapping the 

extent and thickness of geohydrologic units, (2) distinguishing 

fine-grained deposits that form confining units from coarsegrained deposits that form aquifer units, (3) delineating 

contiguous units that have similar lithology and hydrologic 

properties (such as lacustrine deposits and till that are less 

transmissive than outwash, or kame sand and gravel deposits 

that are more transmissive), and (4) categorizing these 

deposits as either confining units or aquifer units. The aquifer 

geometry in the study area is complex due to multiple ice 

advances. Glacial and post-glacial erosion also substantially 

modified the upper parts of the valley fill. There are more well 

data in the shallower parts of the valley fill than in the deeper 

parts; therefore, the aquifer geometry is better defined in the 

shallower parts of the study area. The most productive aquifers 

in the western and central part of the upper Sixmile Creek 

valley are two confined sand and gravel units (figs. 7 and 8), 

whereas in the eastern part of the upper Sixmile Creek valley 

and in the headwaters of the West Branch Owego Creek 

valley, there is an unconfined aquifer as well as a confined or 

leaky confined aquifer. 

Seismic-refraction surveys, well logs, and maps of 

geologic deposits were used to determine the geometry and 

thickness of the aquifers and confining units at selected 

locations. While seismic-refraction surveys may be useful 

for determining depths to saturated deposits and depths to 

the top of bedrock, they yield little data that can be used 

to differentiate between the various types of sediment that 

comprise the valley-fill deposits. However, results from 

seismic-refraction surveys combined with well logs and field 

observations made at geologic outcrops and exposures are 

valuable for describing the hydrogeologic framework of the 

aquifer system. 

Unconfined Aquifers

An unconfined headwater aquifer extends from the 

Valley Heads Moraine in the central part of the study area to 

the outwash plain in the West Branch Owego Creek valley 

in the east part of the study area (figs. 7 and 8). Headwater 

aquifers are at major drainage divides (in this case the divide 

between the Susquehanna River basin and the Lake Ontario 

basin shown in fig. 4) and are not crossed by large perennial 

streams but are drained by small headwater streams. The 

unconfined headwater aquifer in the study area occupies 

a broad valley partially filled with stratified drift that was 

deposited when meltwater flowed across the watershed 

divide during deglaciation. The unconfined headwater aquifer 

consists mostly of coarse-grained deposits in the upper part of 

the valley fill, but lenses or bodies of fine-grained lacustrine 

sediment are also present. Throughout much of the year, 

the upland tributaries typically go dry where they cross the 

valley floor before joining the West Branch Owego Creek. 

Streamflow begins once the volume of recharge from upland 

runoff and direct precipitation on the valley floor exceeds 

the capacity of the upper, unconfined aquifer in the stratified 

drift to transmit water downvalley. Because the headwater 

of the West Branch Owego Creek valley does not contain a 

large, perennial stream, there is little potential for substantial 

recharge by induced infiltration from large pumping wells. 

However, the potential for recharge by induced infiltration 

from large pumping wells increases further downvalley (to the 

east) where the stream discharge becomes greater. 

The Valley Heads Moraine has an irregular hummocky 

land surface with moderate relief, which contrasts with 

headwaters of the West Branch Owego Creek valley that 

drained away from the ice and where all or most of the valley 

floor consists of low planar surfaces such as flood plains and 

terraces that are commonly less than 20 ft above stream level. 

East of the Valley Heads Moraine and in the West Branch 

Owego Creek valley, most homeowner and agricultural wells 

are shallow, ranging in depth from 25 to 90 ft. Well logs 

indicate that some wells are finished in an unconfined sand 

and gravel aquifer, but others indicate that a thin clay layer 

was penetrated. It is uncertain whether this thin clay layer 

is extensive and continuous enough to form a substantial 

confining unit, or if it is a discontinuous lens that is not an 

extensive confining bed.

Data from a deep test well (Climate Response Network 

well TM1968; well log shown in fig. 9; location shown in 

fig. 6) drilled in the outwash deposits just east of the crest 

of the Valley Heads Moraine indicate that the unconfined 

sand and gravel aquifer is 62 ft thick, and there are two thin, 

confined aquifers at depths of 102 to 110 ft (medium to 

coarse sand) and 135 to 140 ft (sand and gravel). At well site 

TM1968, drilling was terminated in very fine sand at depth 

170 ft; a deeper well would need to be drilled to determine 

whether a basal confined aquifer is present on top of bedrock. 

In well TM1968, the casing was backfilled with sediment and 

grout to a depth of 83.5 ft and perforated from 55 to 58 ft in 

the unconfined aquifer. 

Well records in the West Branch Owego Creek valley 

indicate that the upper unconfined aquifer is at least 80 to 90 ft 

thick, but there are no wells that extend to bedrock in the 

deepest part of the valley. Results from a seismic-refraction 

survey along Flatiron Road in the eastern part of the study 

area (figs. 6, 10A and 10B) indicated that depth to bedrock 

(thickness of unconsolidated deposits) was approximately 

170 ft at the southern end of the seismic line (near S1 in 

figs. 10A and 10B) and decreased northward to about 55 ft to 

bedrock (near S6 in figs. 10A and 10B). However, there are no 

stratigraphic data on the types of valley-fill materials at depths 

greater than 90 ft. 
Hydrology of the Valley-Fill Aquifer System 17

0

1,215

1,206

1,200

1,176

1,168

1,143

1,139

1,113

1,108

1,263

 Altitude

DEPTH BELOW LAND SURFACE, IN FEET

Sand and gravel with some clay, grey, 

subround to round clasts

Sand and gravel, brown, fine to coarse pebbles, 

some cobbles, subround to round clasts, medium 

to coarse sand with some fine sand, moist

Sand and gravel, brown, fine to coarse pebbles, 

some cobbles, subround to round clasts, medium 

coarse sand with some fine sand, wet

Sand and gravel, brown, fine to coarse pebbles, 

some cobbles, subround to round clasts, medium 

to coarse sand with some fine sand, wet, makes 

water at approximately 10 gallons per minute 

Developed well 30 minutes at 20 gallons per minute 12/29/04

U.S. Geological Survey Climate Response Network Well TM1968

Well located 1 mile east of Slaterville Springs, NY

Well site name: TM1968

Site ID: 422323076190301

Latitude: 42° 23' 22.80"

Longitude: 076° 19' 03.03"

Date completed: 12/29/04

Drilling contractor: Barber & DeLine, Tully, NY

Well depth: 58 feet (6-inch-diameter casing)

Casing: 6-inch diameter steel casing

Altitude of land surface 1,278.2 feet

above National Geodetic Vertical Datum of 1929

Altitude top of casing = 1,280.69 feet

WELL DEPTH = 58 feet

6-inch steel casing

Water Level = 15.0 feet 

12/29/2004 15

63

72

78

102

110

135

139

165

170

Silty clay, grey, trace stones, firm (till?)

Silty clay till, grey, fine to medium pebbles 

embedded in silt clay matrix

Casing above ground = 2.5 feet

Clay, grey

Fine sand, grey

Some zones consist mostly of medium to 

coarse sand

Gravelly layer 85-87 feet

Pebbly sand, medium to coarse sand, fine pebbles

Fine sand, trace fine sand

Sand and gravel, fine to coarse pebbles

Bentonite seal

at 91-93 feet

Sediment infill

from 83.5 to 91 feet

(1/13/05)

Casing perforated

55-58 feet

Water 

enters

casing 

Sediment heaved

up into casing to 93 feet

Figure 9. Well log of Climate Response Network well TM1968, near Slaterville Springs, New York.
18 Geohydrology & Water Quality of the Valley-Fill Aquifer System in the Town of Caroline, Tompkins County, New York 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 Geophones 1 2 3 4 5 6 7 8 9 10 11 12 

B

B'

S1

S3

S4

S6

S5

S2

TM 62

TM2129

TM2302

76°17'30" 76°17'

42°23'0"

42°23'30"

Seismic-refraction survey line

1 2 3 4 5 6 7 8 9 10 11 12

S1 S2

Shot Shot

Geophones

EXPLANATION

Base from U.S. Geological Survey (1949), Dryden, NY, 1:24,000

TM 62 Well and well site name—Site name is assigned

by the U.S. Geological Survey. Well data are

in Appendix 1 at end of report

250 500 METERS

2,000 FEET

0

0 250 500 1,000

Town of

Caroline

Aquifer area Area shown

in this figure

A

Figure 10. Seismic-refraction survey B–B' along Flatiron Road, Town of Caroline, New York: (A) location of 

line of section, and (B) seismic profile.
Hydrology of the Valley-Fill Aquifer System 19

Thin (10 to 20 ft thick) alluvial, deltaic, and outwash sand 

and gravel deposits on the surface in low-lying areas in the 

central to western parts of the upper Sixmile Creek valley may 

form discontinuous unconfined aquifers (figs. 5 and 7). These 

thin, discontinuous aquifers generally are not reliable sources 

of water during drier periods of the year (especially droughts), 

when part, or all, of these aquifers may go dry. Springs that 

discharge from the aquifers at the base of the steep deltaic 

bluffs at Brooktondale (fig. 7) are used to supply water to 

several homes and apartment units.

Confined Aquifers and Confining Units

Two confined aquifers constitute the major water-bearing 

units in the western part of upper Sixmile Creek valley 

(figs. 7 and 8). One or more confined aquifers may also be 

present beneath the unconfined aquifer in the eastern part of 

the study area (beneath the Valley Heads Moraine and West 

Branch Owego Creek valley), but there are little data for 

the deeper parts of the valley fill in this area to confirm this 

possibility. 

Results of two seismic-refraction surveys in the western 

part of the study area (figs. 11A, 11B, and 11C) indicated 

that (1) along seismic profile C–C′ north of Landon Road 

(fig. 11B) the valley-fill deposits are about 80 ft thick at the 

northern end of the line at C′ and thicken southward to about 

100 ft at C, and (2) along VanDemark Road (seismic profile 

D–D′) (fig. 11C) the valley-fill deposits are about 100 ft thick 

at the northern end of the line (around the 1,800-ft mark) and 

thicken slightly southward to about 120 ft (around the 1,500-ft 

mark), before thinning to about 110 ft further southward to the 

end of the line (around the 1,000-ft mark). 

0 500 1,000 1,500 2,000 2,500 3,000 3,500

Land surface

1,000

1,050

1,100

1,150

1,200

1,250

1,300

1,350

Shot

1

Shot 

3

Shot

2

Shot

5

Shot

4

Shot

6

B'

Spread B

Spread C

Spread A

HORIZONTAL DISTANCE, IN FEET

VERTICAL EXAGGERATION X 5

VERTICAL DATUM IS NATIONAL GEODETIC

VERTICAL DATUM OF 1929

FEET

Saturated unconsolidated deposits, 

velocity = 5,000 feet per second

Shale bedrock,

velocity = 14,900 feet per second

B

South North

Unsaturated 

unconsolidated 

deposits

B

EXPLANATION

TM 62

TM 62

TM 2129

TM 2302

Well and well site name—Site name is

assigned by the U.S. Geological Survey.

Well data are in Appendix 1 at end of report

Figure 10. Seismic-refraction survey B–B' along Flatiron Road, Town of Caroline, New York: (A) location of 

line of section, and (B) seismic profile.—Continued
20 Geohydrology & Water Quality of the Valley-Fill Aquifer System in the Town of Caroline, Tompkins County, New York

Figure 11. Seismic-refraction surveys, Town of Caroline, New York: (A) location of surveys C–C' (north 

of Landon Road) and D–D' (along VanDemark Road) in upper Sixmile Creek valley, (B) seismic profile C–C' 

north of Landon Road, and (C) geohydrologic section D–D' along VanDemark Road.

EXPLANATION

TM1979 Well and well site name—Site name is

assigned by the U.S. Geological Survey.

Well data are in Appendix 1 at end of report

Seismic-refraction survey line

1 2 3 4 5 6 7 8 9 10 11 12

S2

S1 S3

Shot Shot

Geophones

C C'

42°23'

42°23'30"

76°24' 76°23'30" 76°23'

0

0

500 1,000 FEET

100 200 METERS

S2

S1

S3

S1

S2

S3

12

10

8

6

2

4

VanDemark Road

Landon Road

1

2

3

5

6

7

8

9

10

11

12

4

Geophones

TM1029

TM1979

NYS Route 79

Landon Road

Base from U.S. Geological Survey (1969), photo revised 1978, 

Ithaca East, NY, 1:24,000

Sixmile 

Creek

Brooktondale Streamgage

Flow

C

C'

D

D'

Unnamed tributary

that receives large amounts

of groundwater discharge

Photo shown in 

figure 17 is here

Town of

Caroline

Aquifer

Area shown

in this figure

area

A
Hydrology of the Valley-Fill Aquifer System 21

Saturated unconsolidated deposits, 

velocity = 5,000 feet per second

Sedimentary bedrock,

velocity = 15,000 feet per second

900

950

1,000

1,050

HORIZONTAL DISTANCE, IN FEET

VERTICAL EXAGGERATION X 5

VERTICAL DATUM IS NATIONAL

GEODETIC VERTICAL DATUM OF 1929

0 200 400 600 800 1,000

C C'

South North

Land surface

Spread C

Shot

1

Shot

2

Shot

3

FEET

B

1,200

Figure 11. Seismic-refraction surveys. Town of Caroline, New York: (A) location of surveys C–C' (north of Landon 

Road) and D–D' (along VanDemark Road) in upper Sixmile Creek valley, (B) seismic profile C–C' north of Landon Road, 

and (C) geohydrologic section D–D' along VanDemark Road.—Continued

The upper confined aquifer is generally 25 to 50 ft 

below land surface. The thickness of the unit typically ranges 

from 5 to 15 ft. The upper confined aquifer is overlain by a 

15- to 30-ft-thick confining unit that consists of a clay till 

in the eastern part of the upper Sixmile Creek valley and 

glaciolacustrine silt and very fine sand in the western part of 

the valley. The confining unit is believed to be extensive in the 

valley. In upper Sixmile Creek valley, many homeowner wells 

(mostly drilled wells but also some driven wells) and the well 

(TM 73) that supplies the Caroline Elementary School tap this 

aquifer. The aquifer is under artesian flowing conditions in 

the low areas between Slaterville Springs and West Slaterville 

(fig. 8). West of West Slaterville, the aquifer is under confined 

conditions but not flowing-artesian conditions.

The basal confined aquifer typically ranges from 75 to 

100 ft below land surface in most places in the upper Sixmile 

Creek valley. The thickness of the aquifer is largely unknown 

because most water-well drillers finish wells in either the 

upper confined aquifer or in the basal confined aquifer and 

do not extend to the bottom of the basal aquifer. The particle 

size of the sediments that comprise the basal confined aquifer 

varies greatly from place to place. At the Caroline Elementary 

School, the basal aquifer was 83 ft thick but was poorly sorted 

in places, consisting of large amounts of sand as well as some 

gravel. The aquifer is overlain by a 30- to 50-ft-thick confining 

unit that consists of glaciolacustrine very fine sand, silt, and 

clay. The confining unit is believed to be fairly extensive 

and thick in the central parts of the valley, but the unit thins 

towards the edges of the valley where it may pinch out in 

places. Many wells in the upper Sixmile Creek valley are also 

finished in the basal confined aquifer, including the Town 

Hall well (TM 986) in Slaterville Springs (fig. 6), which is a 

flowing artesian well. 

It is unknown whether the basal aquifer extends beneath 

the Valley Heads Moraine and into the West Branch Owego 

Creek valley in this study area. However, basal sand and 

gravel aquifers are common in front of the Valley Heads 

Moraine in other valleys in central New York (Miller and 

others, 1998; Kappel and Miller, 2003).

Bedrock Aquifers

The upper Sixmile Creek basin is underlain by Devonianage sedimentary rock units consisting mostly of shales and 

siltstones. Water movement is controlled by secondary 

permeability in the joints or fractures in the rock and typically 

predominates along bedding planes. Few wells in Tompkins 

County penetrate more than about 300 ft into the sedimentary 

rock units, and little hydrologic information is available 

beyond that depth. Generally, water-well drillers do not 

drill wells greater than 300 ft deep because water becomes 

increasingly more mineralized and less potable with depth. 
22 Geohydrology & Water Quality of the Valley-Fill Aquifer System in the Town of Caroline, Tompkins County, New York Potentiometeric surface (basal confined aquifer) South FEET U.S. Geological Survey streamgage at Brooktondale Seismic-refraction survey along VanDemark Road

TM1979

TM1029

0 100 200 300 400 500 600 700 800 900 1,000 1,100 1,200 1,300 1,400 1,500 1,600 1,700 1,800 1,900 2,000

D

North

D'

HORIZONTAL DISTANCE, IN FEET

1,0401,0201,000

980960940920900880

Sixmile Creek

Springs Water table (unconfined aquifer)

Potentiometric surface (upper confined aquifer)

EXPLANATION

Ice-contact silty sand and gravel (facies 1)—Forms an extensive confined aquifer that typically overlies bedrock, consists of meltwater deposits (subglacial and ice-marginal streams) that were on top of the ice, in crevasses, or beside stagnant ice at the ice margin. In places, this unit may contain large amounts of fine to medium sand that may result in turbidity when pumped by wells

VERTICAL EXAGGERATION X 4 

VERTICAL DATUM IS NATIONAL GEODETIC

VERTICAL DATUM OF 1929

C

Bedrock (shale and siltstone)—Forms the bottom confining unit that underlies the basal confined sand and gravel aquifer

Deltaic sand and gravel (facies 3)—May form a minor unconfined aquifer; however, this thin aquifer may not be a reliable source of water during dry periods and especially during droughts, when parts of the aquifer may become unsaturated

Sand and gravel (unknown origin)—Forms a confined aquifer; however, Glaciolacustrine very fine sand and silt (facies 2)this unit may be discontinuous, thin, and consist of silty gravel, in places

—Forms the

 top confining unit over the upper confined aquifer (where present)

Till—Poorly sorted clayey silt matrix with embedded stones, compact,dense 

TM 1029 Well and well site name—Site name is assigned by the U.S. Geological Survey.

Figure 11. Seismic-refraction surveys. Town of Caroline, New York: (A) location of surveys C–C' (north of Landon Road) and D–D' (along VanDemark Road) in upper Sixmile Creek valley, (B) seismic profile C–C' north of Landon Road, and (C) geohydrologic section D–D' along VanDemark Road.—Continued
Hydrology of the Valley-Fill Aquifer System 23

In sedimentary rocks in Connecticut, the number of joints, 

fractures, and bedding-plane openings typically decreases with 

depth (Olcott, 1995); permeability of the rock units similarly 

decreases until groundwater movement is extremely slow or 

ceases at some depth. Decreased circulation of groundwater 

results in an increase of dissolved minerals in the water and 

at some depth the water becomes nonpotable. Brackish water 

in Devonian-age rocks is ubiquitous throughout central and 

western New York and is typically no more than 100 to 150 ft 

below large tributary and major valley floors (A.D. Randall, 

U.S. Geological Survey, written commun., 2008). The density, 

width of opening, and connectiveness of water-bearing 

fractures has not been investigated for bedrock geohydrologic 

units in this study area. 

Bedrock aquifers are important water resources in the 

region because they are present everywhere, even though the 

yields available from individual bedrock wells completed 

in bedrock wells are generally much lower than from wells 

finished in sand and gravel. In the uplands, bedrock is both the 

sole dependable source as well as the most economical source 

of potable water for homes, commercial establishments, and 

small public-supply systems. Specific capacity, a measure 

of the number of gallons per minute pumped per foot of 

drawdown in a well, was computed for 66 bedrock wells in 

south-central New York and averaged 0.46 (gal/min)/ft (Kontis 

and others, 2004) for shale and siltstone geohydrologic units, 

which is generally at least a magnitude in order less than that 

for sand and gravel aquifers. In the upper Sixmile Creek basin, 

water-well drillers’ logs indicate that yields of 2 to 5 gal/min 

can usually be obtained from wells that tap bedrock at most 

locations and, occasionally, yields as large as 10 to 30 gal/min 

and yields less than 1 gal/min are reported (table 1). Water 

withdrawn from bedrock aquifers constitutes a large 

percentage of total groundwater withdrawals from the upper 

Sixmile Creek basin. 

Groundwater Levels and Flow Paths

In the part of the study area where the valley-fill 

aquifer is unconfined, recharge and discharge can occur 

simultaneously at varying rates such that storage is either 

increasing (rising groundwater levels) or decreasing (declining 

water levels). Patterns in water-level fluctuations differ 

from place to place as a function of aquifer type, hydraulic 

conductivity of the aquifer, and distance to the nearest 

discharge or recharge areas such as streams or pumping 

wells. For example, in the permeable unconfined aquifer, the 

water table is generally within a few feet of stream stage in 

West Branch Owego Creek and fluctuates similarly to the 

water level in the stage in the stream. In distal areas from the 

stream, the water table is several feet above the stream, and 

annual water-level trends are largely affected by fluctuations 

in precipitation. 

Natural changes in storage, as reflected by fluctuations 

in the water table, generally follow seasonal patterns. These 

include short, relatively well-defined periods of increased 

storage in the spring and late fall, when recharge to the aquifer 

exceeds discharge from the aquifer, and longer, poorly defined 

periods of decreased storage in the summer and winter, 

when discharge generally exceeds recharge. Also, a regional 

drought that reduces recharge over a large area can result in 

reduced storage and yield from sand and gravel aquifers in the 

affected area.

The water table in the unconfined aquifer, the 

potentiometric surface in the upper confined aquifer, and the 

general direction of groundwater flow in both aquifers are 

shown in figure 12. The water-table map was constructed 

using 16 water-level measurements made by water-well 

drillers during the years 2002–07, by USGS personnel during 

this investigation (2002–06), and during a previous study 

by Randall and others (1988). Also, altitudes of perennial 

streams and of ponds and wetlands that are connected to the 

unconfined aquifer were also used to construct the water-table 

Table 1. Range, mean, and median reported well yields and well depths in the Sixmile Creek and West Branch Owego Creek 

valley-fill aquifer, Town of Caroline, New York. 

[Data reported from water-well drillers. gal/min, gallons per minute; ft, feet]

Aquifer type

Well yields Well depths Number 

of 

artesian 

flowing 

wells

Number 

of

 wells

Range 

(gal/min)

Mean 

(gal/min)

Median 

(gal/min)

Number 

of 

wells

Range 

(ft)

Mean 

(ft)

Median 

(ft)

Unconfined sand and gravel 11 7–50 18.3 15 17 20–90 41.8 35 0

Confined sand and gravel 18 5–30 14.6 12 31 29–138 64.5 57 5

Bedrock 17 1–30 8.4 6 22 59–300 148.6 135 1
24 Geohydrology & Water Quality of the Valley-Fill Aquifer System in the Town of Caroline, Tompkins County, New York

Figure 12. Water table in the unconfined aquifer and potentiometric surface in the upper confined aquifer in upper Sixmile Creek valley and West Branch Owego Creek valley, Town of Caroline, New York.

Sixmile

Creek

Willow Creek

West Branch Owego

Creek

Barille channel erosion

control project. Reach of Sixmile

Creek in which large volumes of water

were observed to 

seep into channel

TOWN OF CAROLINE

TOWN OF DRYDEN

TOWN OF RICHLAND

TOWN OF CAROLINE

TOWN OF CAROLINE

TOWN OF DRYDEN

Brooktondale

Caroline

TIOGA COUNTY

TOMPKINS COUNTY

0 1 MILE 0.50 1 KILOMETER 0.5

Base from U.S. Geological Survey, Seamless Data Distribution System, accessed in 2007 at http://seamless.usgs.gov Universal Transverse Mercator projection, Zone 18

No data

No 

data

No data

No data

1,080

1,000

1,050

1,100

1,150

1,263

1,299

1,063+

flows

1,280

937

1,292 1,014

1,264

1,130

1,136

1,254

1,256

1,038

1,270

1,272

1,255

1,144

1,066

1,180

1,092+

flows

1,262.6

1,256.5

1,116.73 1,103.8+ 1,118.5

1,037.64

1,220.69

1,259.72

1,013.18

1,008.36

1,006.09

x

1,245

1,250

1,270

1,270

1,280

~1,212

1,260

1,200

1,180

1,290

1,280

1,260

1,291.6

985

1,116.73

EXPLANATION

1,270 Water table—Shows altitude of the surface of the water table in the unconfined aquifer derived from measurements made 

from 2000 to 2007. Contour interval 10 feet. Datum is National Geodetic Vertical Datum of 1929

1,050 Potentiometric surface—Shows altitude of the water level in the upper confined aquifer derived from measurements made

from 2000 to 2007. Contour interval 10 feet. Dashed where approximate. Datum is National Geodetic Vertical Datum of 1929

Aquifer boundary—Approximate boundary of valley-fill aquifer (Dashed where cut off)Direction of groundwater flow—Blue arrows show direction of flow in upper confined aquifer; red arrows show directionGroundwater divideof flow in unconfined aquifer

1,092+ flows

Boundary of the Valley Heads Moraine

Surface-water divide—Drainage divide between water draining to the Lake Ontario basin to the north and water draining to

Unchanneled hillsides adjacent to valley

the Susquehanna River basin to the south

—Runoff and groundwater inflow from these areas recharge the unconfined aquifer

Non-flowing artesian well with water-level measurement—Blue number is altitude of water level in the upper confinedaquifer, black number is altitude of water level in the unconfined aquiferFlowing-artesian well with water-level measurement—Number is altitude of water level

76°17' 76°24'

42°25'

42°22'
Hydrology of the Valley-Fill Aquifer System 25

contours. Although water-level measurements from Randall 

and others (1988) were from a previous period, the average 

annual fluctuation is only expected to be about 5 ft in most 

of the low-lying areas because surface-water features such 

as large wetlands and streams are widespread throughout the 

valley floor in the eastern part of the aquifer (fig. 5). In other 

valleys that contain the Valley Heads Moraine and where 

groundwater studies have been conducted, these surfacewater bodies (wetlands, kettle ponds, and streams), and the 

groundwater in the vicinity of these surface-water bodies, have 

water levels that typically fluctuate less than 5 ft during the 

year (Kappel and others, 2001; Miller and Staubitz, 1985). 

Also, the annual water-level fluctuation was less than 

5 ft in the western part of the study area where, in well 

TM 984, the difference in water levels during a period of 

low-level conditions in the late fall (depth to water level below 

land surface was 13.44 ft on December 12, 2002) and high 

water-level conditions after winter snowmelt (depth to water 

level below land surface was 10.90 ft on March 24, 2003, 

Appendix 1) was 2.54 ft. However, in more distal areas from 

surface-water features and near the groundwater divide in the 

Valley Heads Moraine, annual fluctuations in the water table 

typically range from 5 to 10 ft as evidenced by fluctuations in 

water levels in a test well completed for this study (see section 

on “Climate Response Network Well”). By using a 10-ft 

contour interval for the water table and allowing for annual 

water-level fluctuation of approximately 5 ft in most places, 

the configuration of the water-table map that was generated 

provides a reasonable representation of average annual watertable conditions. 

A groundwater divide in the central part of the study area 

(fig. 12) separates groundwater flow that moves westward 

into the Lake Ontario basin from that flowing eastward into 

the Susquehanna River basin. The groundwater divide does 

not exactly coincide with the surface-water divide (fig. 12), 

which is not an uncommon situation in other valleys in central 

New York where the Valley Heads Moraine is found, such as 

in Tully Valley, NY (Kappel and others, 2001). Groundwater 

in the unconfined aquifer on the east side of the Valley Heads 

Moraine generally flows from the edges of the aquifer toward 

the central part where it discharges into a large wetland and 

eventually the West Branch Owego Creek. 

The potentiometric surface in the upper confined aquifer 

was determined through 14 water-level measurements 

made during this investigation by water-well drillers during 

the years 2002–07 and by USGS personnel during this 

investigation (2002–08). Groundwater in the upper confined 

aquifer (fig. 8) is under artesian conditions or artesian-flowing 

conditions except where it discharges to springs along bluffs in 

the western end of the aquifer (figs. 7, 8, and 12). 

The potentiometric surface in the basal confined aquifer 

was determined through 11 water-level measurements 

made during this investigation by water-well drillers during 

the years 2002–07 and by USGS personnel during this 

investigation (2002–08). Groundwater in the basal confined 

aquifer in upper Sixmile Creek valley flows westward from 

the Valley Heads Moraine under artesian conditions, where it 

discharges to streams and springs along bluffs at the western 

edge of the aquifer (figs. 7, 8, and 13). Most wells in the 

low-lying areas near Slaterville Springs and West Slaterville, 

NY, that tap the confined aquifers are under artesian-flowing 

conditions with hydraulic heads about 5 to 20 ft above land 

surface, but other wells that are several tens of feet higher 

on terraces and kames along the valley walls do not flow, 

although they too are artesian. The existence or absence of 

a basal aquifer in West Branch Owego Creek valley was not 

determined. However, basal aquifers are common in other 

major valleys in central New York, so it is probable that there 

is one in the West Branch Owego Creek as well. Sources of 

recharge to the basal confined aquifer are uncertain. One likely 

source of recharge is from groundwater in the underlying 

bedrock that probably flows to the basal aquifer in the bottom 

and along the sides of the valley.

In December 2004, a hole was bored at the Caroline 

Elementary School (figs. 6 and 7) to a depth of 170 ft to 

determine the stratigraphy of the valley-fill deposits and 

vertical hydraulic gradients in geohydrologic units, and 

to collect groundwater samples. Bedrock was penetrated 

at a depth of 160 ft and a nested pair of wells (TM 994 

and TM1967) was installed at two confined aquifer zones 

(fig. 14). Well TM 994 is 39 ft deep and is finished in the 

upper confined aquifer, and well TM1967 is 92 ft deep and is 

finished in the basal confined aquifer. On January 13, 2005, 

and July 18, 2005, the water levels in these wells differed by 

only 1.1 and 1.2 ft, in altitude, respectively, with the deeper 

well (TM1967) having a higher hydraulic head than the 

shallow well (TM 994). The water-level altitudes for wells 

TM1967 and TM 994 on January 13, 2005, were 1,041.2 and 

1,040.1 ft, respectively; on July 18, 2005, they were 1,038.9 

and 1,037.7 ft, respectively. The higher hydraulic head in 

the basal confined aquifer indicates that there is an upward 

hydraulic gradient in this area from the basal to the upper 

confined aquifer. 

At the western edge of the upper Sixmile Creek valley, 

the heads in the upper confined aquifer and in the basal 

confined aquifer differ by several tens of feet because the 

altitudes of the discharge areas have a large effect on heads 

in the aquifers in that area (figs. 8 and 11C). In the vicinity 

of Brooktondale, NY, groundwater discharges from the basal 

aquifer at the sand and gravel/bedrock contact at the base of 

the bluff, whereas groundwater in the upper aquifer discharges 

at the sand and gravel/till contact 60 to 70 ft higher up the 

bluff (figs. 8 and 11C).

Climate Response Network Well

The USGS, in cooperation with the New York State 

Department of Environmental Conservation, collects waterlevel data nationwide from wells in the USGS Climate 

Response Network (CRN). In 2006, the Climate Response 

Network contained more than 500 wells nationwide, 

and beginning on December 30, 2004, well TM1968 
26 Geohydrology & Water Quality of the Valley-Fill Aquifer System in the Town of Caroline, Tompkins County, New York

Figure 13. Potentiometric surface in the basal confined aquifer in upper Sixmile Creek valley, Town of Caroline, New York.

Sixmile

Creek

Willow Creek

West Branch

Owego

Creek

TOWN OF DRYDEN

TOWN OF CAROLINE

TOWN OF RICHLAND

TOWN OF CAROLINE

TIOGA COUNTY

TOMPKINS COUNTY

TOWN OF CAROLINE

TOWN OF DRYDEN

Brooktondale

Caroline

0 1 MILE 0.5

0 1 KILOMETER 0.5

Base from U.S. Geological Survey, Seamless Data Distribution System, accessed in 2007 at http://seamless.usgs.gov Universal Transverse Mercator projection, Zone 18

1,066

1,065

1,038.91

1,060+

flows

966.62

No data

No 

data

No data

No data

1,070

1,050

1,000

950

No data on 

confined aquifer

beneath moraine

1,150

1,100

1,050

1,109+

flows 1,111 flows

1,130 1,129

1,125

1,136

1,122+flows

1,255

EXPLANATION

1,050 Potentiometric surface—Shows altitude of the water level in the basal confined aquifer derived 

from measurements made from 2000 to 2007. Contour interval 10 feet. Dashed where approximate. Datum is National Geodetic Vertical Datum of 1929Aquifer boundary—Approximate boundary of valley-fill aquifer. (Dashed where arbitrarily cut off)Direction of groundwater flowNon-flowing artesian well with water-level measurement—Number is altitude of water level

1,109+

flows Flowing-artesian well—Number is altitude of where water was noted to flow (either out from top of casing or land surface). Actual water level in aquifer is above this altitude

1,111

flows Flowing-artesian well with water-level measurement—Number is altitude of water level

Mostly unconfined

aquifer area

(extent of confined

aquifer unknown)

1993 breach

of aquifer at

Buffalo Road

Bridge

76°17' 76°24'

42°25'42°22'
Hydrology of the Valley-Fill Aquifer System 27

Figure 14. Well log and construction details of U.S. Geological Survey test wells TM 994 and TM1967 at Caroline 

Elementary School near Slaterville Springs, New York.

1,004

984

970

887

877

Sand and gravel, fine to coarse pebbles, 

subround to round clasts, many exotics, 

(crystallines), makes water

Sand and gravel, fine to coarse 

clasts, subround to round clasts, makes 

water at approximately 20 gallons per minute

Developed well 1 hour at 25 gallons

per minute

12/28/04

Casing hit refusal at 92 feet, where a 3 feet 

diameter boulder was encountered from 

92-95 feet. Casing ends at 92 feet, borehole 

was drilled through boulder using drill 

rods to depth of 170 feet. A thick sequence 

of sand and gravel was encountered 

from 77 to 160 feet. 

Silty clay, grey, massive, no stones, 

soft

Fine sand, greyish brown, well 

sorted 

Shale, grey

1,037

1,047.0

1,017

Sand and gravel, brown, fine to coarse 

pebbles, some cobbles, subround to round

clasts, moist

Silt and very fine sand, grey, massive, no 

stones

Silt mixed with some stones near bottom 

of unit

0

DEPTH BELOW LAND SURFACE, IN FEET

10

30

43

 63

 77

92

160

170

Altitude (alt.) land surface 

WELL DEPTHS:

92 feet (2-inch diameter casing well)

39 feet (6-inch diameter steel casing with 

perforations from 37 to 39 feet)

Water level upper confined aquifer 

= 9.3 feet below land surface 

(alt. = 1,037.7), 7/18/2005

Water level basal confined aquifer 

= 8.0 feet below land surface 

(alt. = 1,038.9), 7/18/2005 

Bentonite clay from 59.4 to 64 feet

separates hydraulic connection

between upper and lower 

confined aquifer 

Water from basal confined

aquifer enters 2-inch diameter well 

from open-end of 6-inch diameter 

casing at 92 feet

2-inch diameter well 

screened from 70. 5 to 80.5 feet

Water from upper confined

aquifer enters 6-inch diameter 

well through perforations in

casing between 37 and 39 feet

U.S. Geological Survey Test Wells TM 994 and TM1967

Caroline Elementary School, Slaterville Springs, NY

Well site name: TM1967, depth = 92 feet

Site ID: 422336076221301

Site name: TM 994, depth = 39 feet

Site ID: 422336076221302

Latitude: 42° 23' 36.26"

Longitude: 076° 22' 13.15"

Date completed: 12/28/04

Drilling contractor: Barber & DeLine, Tully, NY

Well TM1967: 2-inch diameter pvc casing), 

Well TM 994: 6-inch diameter steel casing)

Casing above ground = 2.0 feet

Altitude TOC (6 inches) = 1,048.97

Altitude TOC (2 inches) = 1,048.58

}

}
28 Geohydrology & Water Quality of the Valley-Fill Aquifer System in the Town of Caroline, Tompkins County, New York

(figs. 6, 7, and 9) in the Town of Caroline, NY, about 1 mi 

east of Slaterville Springs, NY, became part of that network. 

The casing of well TM1968 is perforated from 55 to 58 ft 

below land surface and open to the unconfined sand and gravel 

aquifer (fig. 9). The primary purpose of the CRN is to portray 

the effects of climate on groundwater levels in unconfined 

aquifers or near-surface confined aquifers that are minimally 

affected by pumping or other anthropogenic stresses. The 

CRN web site (http://groundwaterwatch.usgs.gov/) provides 

users with current groundwater conditions throughout the 

United States and allows users to view and retrieve past waterlevel data for network wells. 

Water levels in well TM1968 are recorded on an hourly 

basis and can be retrieved and plotted on a hydrograph 

at the site web page: http://groundwaterwatch.usgs.gov/

CRNSites.asp?S=422323076190301. The site page also has 

information related to an individual well such as location, 

well depth, and aquifer type. When more than 4 years of 

data (by 2009) and less than 10 years of data are collected, 

the minimum, median, and maximum water levels are 

displayed. When more than 10 years of data (by 2014) have 

been collected, water-level percentiles are computed and 

displayed in addition to monthly statistics that are depicted on 

a monthly bar chart. This chart provides a powerful statistical 

combination of historical data with recent measurements. After 

10 years of record are collected, water-level measurements 

from the most recent 12-month period are plotted on an 

annual statistical hydrograph, providing current groundwater 

conditions compared to historical groundwater conditions for 

any given month.

The water level below land surface from January 1, 

2005, through December 31, 2007, in CRN well TM1968 is 

shown in the hydrograph in figure 15. During this period, the 

maximum fluctuation of the water table was 9.7 ft, with the 

lowest water level at 20.4 ft below land surface on October 15, 

2005, and the highest water level at 10.7 ft below land surface 

on April 5, 2005.

Groundwater Recharge

The amount of recharge to stratified-drift aquifers is a 

key determinant of the long-term availability of water. More 

recharge water is available to unconfined sand and gravel 

aquifers than to confined aquifers.

Unconfined Aquifers

Recharge derived from upland sources provides a 

substantial percentage of total recharge to the unconfined 

aquifers in upper Sixmile Creek and West Branch Owego 

Creek valleys. Sources of recharge to the unconfined aquifers 

include (1) precipitation (rain and snowmelt) that falls directly 

on the land surface above the stratified drift and infiltrates 

to the saturated zone; (2) unchanneled runoff from upland 

hillsides immediately adjacent to the stratified drift, flowing 

downhill as surface or shallow subsurface runoff during and 

after storms; (3) infiltration from the upland stream channels 

where they cross the stratified drift and lose water to the 

aquifer; and (4) groundwater inflow from adjacent till or 

bedrock (fig. 16).

Direct Infiltration of Precipitation on the Valley Floor

A major source of recharge to the unconfined aquifers 

in the study area is direct infiltration of precipitation into 

the saturated zone. Runoff is generally negligible over 

undeveloped areas of sand and gravel, so all precipitation 

that is not lost to evapotranspiration recharges the unconfined 

aquifer. Evapotranspiration includes evaporation, in which 

water is changed from liquid into vapor, and transpiration by 

which water vapor escapes from living plants back into the 

atmosphere. In the southeastern part of Tompkins County, 

the annual evapotranspiration is estimated to range between 

19 and 20 in. (Kontis and others, 2004, plate 1). This amount 

is roughly equivalent to half of the annual precipitation in this 

area based on the mean-annual precipitation for 1995–2006 

at the National Weather Service station at Cornell University, 

which was about 40 in. (the annual recharge to the unconfined 

aquifer in the study area by direct infiltration is about 20 in., 

or half the mean annual precipitation). Therefore, the average 

annual recharge from precipitation that falls directly over 

the unconfined aquifer may be estimated by multiplying the 

area of the unconfined aquifer 2.38 mi2 (6.58 x 107 ft2) by the 

annual rate of precipitation minus evapotranspiration, 20 in/yr 

(1.67 ft/yr), which yields a recharge rate of 1.11 x 108 ft3/yr or 

3.54 ft3/s (2.29 Mgal/d).

The hydrograph (a plot of water level versus time) 

depicted for well TM1968 in figure 15 illustrates when 

recharge occurred in the unconfined aquifer in the study area. 

Periods of recharge (when groundwater storage in the aquifer 

is increasing) are represented by rising groundwater levels; 

this occurs mostly during late fall, winter, and early spring, 

just before and just after the growing season (fig. 15). Little 

recharge occurred during the growing season from late spring 

to early fall in 2005 and 2007, when the evapotranspiration 

rate typically exceeds the precipitation rate and when these 

were periods of below-normal precipitation. In 2006, however, 

there were several periods of above-normal precipitation 

during the summer and fall in which the rate of infiltration 

exceeded the rate of evapotranspiration, resulting in several 

spikes in groundwater levels during the summer and fall. 

Large rises in groundwater levels such as those observed 

in well TM1968 during the growing season (May through 

October) are uncommon in central New York.

Not all of the unconfined aquifer in the West Branch 

Owego Creek valley receives recharge from direct infiltration 

of precipitation because the precipitation that falls on areas 

with a high water table, such as the large wetland in the central 

part of the West Branch Owego Creek valley, is rejected by the 

groundwater system and becomes surface-water runoff that 

eventually flows into West Branch Owego Creek.
Hydrology of the Valley-Fill Aquifer System 29

Unchanneled Runoff and Groundwater Inflow from 

Adjacent Hillsides

Additional sources of recharge to the unconfined 

aquifer are from adjacent hillsides to the valley. Runoff and 

groundwater inflow from these hillsides infiltrate into the 

unconfined aquifer along the edges of the valley (figs. 12 and 

16). Average annual runoff from upland hillsides may be 

estimated by multiplying the average annual runoff rate for 

southern Tompkins County, about 20 in/yr (1.67 ft/yr, Kontis 

and others, 2004, plate 1), by the area of the unchanneled 

hillsides 2.36 mi2 (6.58 x 107 ft2, fig. 12) which yields a 

total recharge potential rate of 1.10 x 108 ft3/yr or 3.56 ft3/s 

(2.30 Mgal/d). Hillsides were excluded where the stream 

channel on the valley floor is adjacent to the hillside and 

intercepts runoff before it enters the aquifer. Unchanneled 

upland runoff typically accounts for 18 to 23 percent of the 

total recharge to unconfined valley-fill aquifers in central New 

York (Miller and others, 1998; Kontis and others, 2004; Miller 

and others, 2008).

Seepage Losses from Upland Tributaries

In the Appalachian Plateau of New York, tributaries that 

drain upland basins typically go dry seasonally where they 

enter larger valleys (Ku and others, 1975). Similarly, in this 

study area, losses from tributaries that flow across alluvial 

fans (fig. 5) adjacent to the main valley walls of upper Sixmile 

Creek valley and West Branch Owego Creek valley are likely 

a major source of recharge to the unconfined aquifer. The 

Figure 15. Hydrograph of the water level below land surface from January 1, 2005, to December 31, 2007, in U.S. Geological 

Survey Climate Response Network well TM1968. (U.S. Geological Survey site Identification number 422323076190301) near 

Slaterville Springs, New York.

10

12

14

16

18

20

22

2005 2006 2007

GROUND

WATER LEVEL, IN FEET BELOW LAND SURFACE

J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D

2

0

4

6

8

10

PRECIPITATION, IN INCHES

. .

..

.

.

.

.

.

EXPLANATION

Monthly precipitation, in inches, at the Ithaca, NY,

national weather station

Water level, in feet below land surface, in

U.S. Geological Survey Climate Response Network

well TM1968
30 Geohydrology & Water Quality of the Valley-Fill Aquifer System in the Town of Caroline, Tompkins County, New York

Unchanneled hillside

adjacent to valley-fill

aquifer

Uplands Large valley

EXPLANATION

Terrace

River

Small upland

tributary

Large upland

tributary

Well

B A

Reach of tributary stream that gains water from groundwater discharge

Reach of tributary stream that loses water to aquifer

Sources of recharge to sand and gravel aquifers in large valleys

Discharge from sand and gravel aquifers

Infiltration of precipitation that falls directly over the valley floor, which infiltrates to

water table unless diverted as evapotranspiration or as storm runoff from pavement 

or saturated soil

Unchanneled runoff from adjacent till-covered hillsides and (or) shallow groundwater 

flow through soil horizons

Lateral and upward flow from regional groundwater flow through bedrock and till

Evapotranspiration

Seepage to main stream in valley

Pumpage from well

Continuous natural seepage loss from tributary stream, typically where tributaries 

flow on their alluvial fans in major valleys (see letters A and B)

A Recharge that moves laterally through the unconfined aquifer

B Recharge that moves downward to confined aquifer

Alluvial

fan

Sand and gravel aquifers

Till

Bedrock

Confining unit—Lacustrine fine sand,

silt, and clay

Figure 16. Sources of recharge to and discharge from valley-fill aquifers in New York.
Hydrology of the Valley-Fill Aquifer System 31

tributary streams in this study area have steep gradients near 

the valley sides and the water level in the tributary channel is 

higher than that of the adjacent groundwater table below; this 

condition favors seepage of substantial amounts of water from 

the tributaries into the valley-fill aquifer. In general, recharge 

from seepage losses from channeled upland runoff can occur 

through the banks as well as the bottom of the stream, and 

lateral hydraulic conductivity of streambank channel deposits 

can substantially exceed vertical hydraulic conductivity of 

the streambed. The rate of infiltration is a function of the 

hydraulic conductivity of the streambed and underlying 

materials, and the difference between the altitude of the stream 

stage and the altitude of the hydraulic head in the aquifer 

beneath the stream. Randall (1978) found that loss rates were 

small (less than 1 ft3/s) near the edges of the main valleys in 

the Upper Susquehanna River basin but were at least 1 ft3/s per 

1,000 ft of channel several hundred feet downstream from the 

valley wall. Similar instances are likely to occur in the upper 

Sixmile Creek valley and West Branch Owego Creek valleys. 

Some stream reaches may show little or no loss because they 

are underlain by fine-grained deposits, rather than the typical 

alluvial sand and gravel, where losses could be much greater.

Confined Aquifers

The confined aquifers in the study area are overlain by 

relatively impermeable fine-grained sediments, which impede 

or slow infiltration of water from surface sources to confined 

aquifers. The sources of recharge to the confined aquifers are 

uncertain. Likely potential sources of recharge to the confined 

aquifers in the study area include (1) the sides of the valley, 

where confined aquifers may either extend up along the flank 

of the bedrock valley wall and become unconfined where 

they crop out at land surface or be overlain and in contact 

with surficial coarse-grained deltaic and fluvial sediments that 

constitute an avenue through which direct precipitation and 

seepage losses from tributary streams can reach the buried 

aquifers (fig. 16); or (2) slow seepage from adjacent finegrained sediment and bedrock where the buried aquifers are 

isolated by the confining units. Another potential source of 

recharge is from release of storage from the confining units 

due to pumping, but this is probably small in this study as 

there are no large pumping wells. Where the confined aquifers 

crop out at or near land surface along the sides of the valley, 

losing tributaries can provide direct recharge to the aquifer in 

these places. However, the main trunk stream, Sixmile Creek, 

is not in direct hydraulic contact with the confined aquifers 

(except in the western part of the study area); therefore, there 

is little interaction between the confined aquifers and Sixmile 

Creek. Where the confined aquifers are mostly isolated and 

completely surrounded by confining units, little or no surface 

water can recharge the aquifers. Isolated confined aquifers 

receive the least amount of recharge of all the aquifer types 

and hence have limited water availability. 

Groundwater Discharge 

Groundwater leaves the aquifers by discharging to 

surface-water bodies (wetlands, ponds, springs, and streams) 

and to pumped wells. Groundwater discharge supplements 

flow in streams during runoff and may comprise most of the 

streamflow during non-runoff periods. 

In the West Branch Owego Creek valley, most 

groundwater in the unconfined aquifer flows eastward from the 

Valley Heads Moraine and discharges to wetlands and West 

Branch Owego Creek in the central part of the valley, and 

some groundwater discharges as underflow through the aquifer 

beyond the east end of the study area. Groundwater seeps 

into surface-water bodies where the water table intersects 

the stream channel or wetland. Most groundwater in the thin 

alluvial unconfined aquifer in upper Sixmile Creek valley 

discharges to Sixmile Creek along most of its course through 

the valley. 

A large volume of groundwater was observed to 

discharge from the sand and gravel deposits on the back 

side of the Valley Heads Moraine into Sixmile Creek in the 

reach where the “Barille channel erosion control project” 

(fig. 12) was conducted in 2005 near Slaterville Springs, 

NY (Albert Morgan, U.S. Geological Survey, oral commun., 

2007). Morgan estimated that 2 to 3 ft3/s of groundwater 

were discharging to a 3,000 ft-long reach of Sixmile Creek 

in this area. Most water appeared to discharge from the 

surficial alluvial and kame moraine sand and gravel deposits 

(unconfined aquifer, figs. 5 and 7) that overlie a clay till 

(confining unit) that is exposed in the bottom of the streambed, 

but during excavation work in the channel, some seepage also 

appeared to come from below the clay till, suggesting that 

some groundwater was discharging from the confined aquifer 

below the clay till confining bed into the channel. 

In upper Sixmile Creek valley, most groundwater (except 

that withdrawn by pumped wells) in the confined aquifers 

eventually discharges to streams and springs in the western 

part of the study area and to withdrawal wells. Upstream 

from the streamgage at Brooktondale, NY, in the west part of 

upper Sixmile Creek valley (figs. 5 and 11A), Sixmile Creek 

and another tributary to the north of the Sixmile Creek have 

incised deep ravines in the valley-fill deposits. The ravine cut 

by Sixmile Creek has eroded through all the unconsolidated 

deposits and has incised a 10- to 30-ft gorge into the bedrock. 

The ravine cut by the unnamed tributary becomes increasingly 

deeper from north to south and penetrates to the top of the 

bedrock just before joining Sixmile Creek at Brooktondale. 

Because Sixmile Creek fully penetrates, and the unnamed 

tributary nearly fully penetrates the valley-fill deposits in this 

area, most groundwater in the valley-fill aquifers discharges 

into the streams. Therefore, the USGS streamgage, located 

at the lip of the exposed hanging valley at Brooktondale, 

NY (04233286), is a favorable site to measure the amount 

of groundwater discharge as well as runoff that flows from 

the basin. The base-flow portion of flow measured at the 

streamgage (groundwater that discharges into the channel) 
32 Geohydrology & Water Quality of the Valley-Fill Aquifer System in the Town of Caroline, Tompkins County, New York

and its volume can be determined by using a hydrographseparation analysis routine that is discussed in the Sixmile 

Creek section of the report.

Seepage to Streams

Streams draining the unconfined aquifer are sustained 

entirely by groundwater discharge during base-flow periods. 

Streamflow in the headwaters ceases seasonally when the 

water table falls below the bottom of the stream channel. 

Rates of groundwater discharge to streams and recharge 

through infiltration from streams are, in part, a function of the 

difference in hydraulic head between the aquifer and stream, 

both of which can vary seasonally.

Tributaries

Although most tributary streams in the upper Sixmile 

Creek and West Branch Owego Creek valleys typically lose 

water where they flow over alluvial fans as they enter the 

main valleys, and the main trunk streams gain water from 

groundwater that discharges to the streams. In some parts of 

upper Sixmile Creek valley, some tributaries gain water from 

groundwater that discharges from the aquifer, such as in the 

Valley Heads Moraine area and in an unnamed tributary near 

Landon Road. This unnamed tributary begins north of Landon 

Road and incises into the valley-fill deposits as it flows 

southward and enters Sixmile Creek 200 ft upstream from the 

streamgage at Brooktondale, NY (fig. 11A). This tributary was 

observed to have fairly constant flow and water temperature, 

both of which are typical characteristics of streams that 

receive groundwater discharge. 

On July 16, 2007, a volumetric discharge measurement 

was made where the unnamed tributary empties into Sixmile 

Creek through a culvert. The measurement was made by 

recording the time it took the stream to fill a 50-gallon 

drum (figs. 11A and 17). The measured discharge was 

150 gal/min (0.33 ft3/s), while the discharge in Sixmile Creek 

at the streamgage at Brooktondale was 5,390 gal/min (12 ft3/s). 

The unitized flow (discharge in cubic feet per second divided 

by drainage area in square miles, of the tributary stream was 

1.87 (ft3/s)/mi2 or 4.7 times more than that of Sixmile Creek at 

the Brooktondale, NY, streamgage, which was 0.4 (ft3/s)/mi2. 

The much larger volume of flow per unit area in the tributary 

stream indicates that the tributary is receiving a greater 

amount of groundwater discharge per unit area in comparison 

to Sixmile Creek.

Sixmile Creek 

Under natural conditions, the principal stream in each 

major valley (in this case, West Branch Owego Creek and 

Sixmile Creek) normally gains water continually from 

stratified-drift deposits, although some reaches may lose flow, 

especially during dry periods. Streams that normally gain flow 

can become local sources of recharge during periods of rising 

stage when the stream level becomes higher than the altitude 

of the water table; recharge by this mechanism is derived from 

temporary bank storage because much of the recharged water 

returns to the stream as the stream level drops.

A real-time, continuous streamgage (streamgage number 

04233286, 27.0 mi2 drainage area) was installed in November 

2002 on Sixmile Creek at Brooktondale (figs. 3 and 11A) and 

is maintained by the USGS New York Water Science Center, 

Ithaca Program Office. Stage and discharge data have been 

collected for over 5 years, and the streamgage is still operating 

at the time of the publication of this report. 

The Brooktondale streamgage is situated where Sixmile 

Creek flows on a bedrock channel and where the stream has 

incised a shallow gorge into shale. The streamgage is about 

Figure 17. Volumetric measurement of a tributary entering 

200 feet upstream of Sixmile Creek at Brooktondale, NY, 

streamgage on July 16, 2007. Location of photograph is shown in 

figure 11A.

Unnamed tributary

discharging into

Sixmile Creek

50

gallon

drum

Sixmile

Creek

Direction 

of 

Flow
Hydrology of the Valley-Fill Aquifer System 33

50 ft above the last of a series of waterfalls that forms the lip 

of the upper Sixmile Creek hanging valley. Graphs depicting 

the stream discharge record for the period from November 14, 

2002, to September 30, 2006, are shown in figure 18.

Peak discharge for the period of record was 4,100 ft3/s 

on April 2, 2005, (fig. 18C), and minimum discharge was 

3.3 ft3/s on October 1, 2, 3, 4, and 6, 2005 (fig. 18D); data are 

published in the New York Annual Water-Data Report 2006 

(U.S. Geological Survey, 2009). For water years (October 1 

through September 30) 2003–06, the mean annual discharge 

was 58.8 ft3/s, mean annual runoff was 29.57 in., and the flow 

per unit area was 2.18 (ft3/s)/mi2; data are published in the 

New York Annual Water-Data Report 2006 (U.S. Geological 

Survey, 2009). The streamgage measures streamflow (fig. 

18), which includes both the storm runoff and base flow that 

drains the upper Sixmile Creek basin. A stream is considered 

to be under base-flow conditions when little or no precipitation 

or snowmelt has occurred in the drainage area for at least 3 

days or if the streamflow hydrograph suggests that discharge 

is steady or slowly declining. Most streamflow under these 

conditions is supplied by groundwater that has discharged to 

the stream. 

The base-flow and runoff components (fig. 19) of 

total streamflow to Sixmile Creek at Brooktondale (upper 

Sixmile Creek basin) and to Sixmile Creek at Bethel Grove 

(lower Sixmile Creek basin) (fig. 3) were calculated using 

a hydrograph-separation computer program HYSEP (Sloto 

and Crouse, 1996) that utilized continuous discharge data 

for 2003–07. HYSEP calculates base flow as a percentage 

of total mean annual flow. The Sixmile Creek streamgages 

at Brooktondale and Bethel Grove meet the recommended 

condition for use of HYSEP in that they are not regulated 

by dams or flood-control reservoirs upstream from the 

streamgaging sites, which would cause an apparent decrease 

in stormflow and an apparent increase in base flow after a 

storm. However, streamflow records at these streamgages span 

a relatively short period (5 years), so these estimates are less 

representative of long-term conditions than streamgages with 

at least 30 years of record. If these 5 years are extremes, either 

low or high, then the estimated discharges may not represent 

long-term average runoff and base-flow values.

Results of the hydrograph-separation analyses for 

2003–07 indicate that base flow constitutes 64 and 56 percent 

of total annual discharge at Sixmile Creek at Brooktondale, 

NY, and Sixmile Creek at Bethel Grove, NY, respectively 

(fig. 19). These results indicate that the flow past Brooktondale 

has a higher component that is derived from base flow 

(groundwater discharge) than at Bethel Grove. This result 

suggests that there is more groundwater discharge from 

aquifer units in upper Sixmile Creek valley than in lower 

Sixmile Creek valley. The greater percentage that is base flow 

in upper Sixmile Creek basin relative to that in lower Sixmile 

Creek basin is likely due to one or both of the following: 

1. At Brooktondale, NY, the stream has eroded and fully 

penetrated the valley-fill deposits including the aquifer 

units, which results in little or no groundwater underflow past the streamgage. At the Bethel Grove, NY, 

streamgage, however, the stream has only partly penetrated the valley-fill deposits. Therefore, a significant 

portion of the groundwater probably flows beneath the 

streamgage as underflow and does not enter the stream 

until further down the valley where the channel has fully 

penetrated the valley-fill deposits and flows on bedrock. 

2. The volume of surficial sand and gravel is greater in the 

upper Sixmile Creek basin than in the lower Sixmile 

Creek basin. Surficial sand and gravel deposits reduce 

rapid runoff by storing precipitation for gradual release. In 

valleys with relatively large amounts of sand and gravel, 

there is proportionally more infiltration of precipitation 

and greater storage capacity; therefore, more groundwater 

discharges to streams than in valleys that contain mostly 

till and lacustrine deposits, which have poor infiltration 

capacity and rapid runoff.

Pumped Withdrawals and Water Availability

No large municipal or industrial pumped wells are in 

the study area. Most groundwater withdrawals are from 

homeowner wells with open-ended, 6-in.-diameter casings, 

but a smaller amount of withdrawals are also made from 

shallow-dug wells and cisterns that collect groundwater that 

discharges from springs (especially in the Brooktondale area). 

Because all homes have septic systems, most groundwater 

that is withdrawn by homeowners returns to the groundwater 

system in the unconfined aquifer or in the surficial confining 

unit, where present. The valley-fill aquifer is the source of 

water for about 200 households, several apartment complexes, 

two mobile home parks, a school, and several farms and 

small businesses. 

About 750 people live in the study area, and almost all 

rely on groundwater from the valley-fill aquifer system. In 

addition, water is used by nonpermanent residents, such as 

students and staff at the Caroline Elementary school (built in 

1959 with an addition added in 1967), and some water is used 

for nonhuman consumption at farms and commercial facilities. 

The estimated total groundwater use for human consumption 

is estimated to be about 74,200 gal/d or 0.11 ft3/s based on 

an average water use of 75 gal/d per person for self-supplied 

water systems in New York (Hutson and others, 2000, table 6) 

and 40 gal/d per person for about 450 nonpermanent residents 

(mostly elementary school students and staff). Unknown 

quantities of water are also drawn from wells in the valleyfill aquifer, including (1) several dairy and horse farms (the 

number of animals is unknown), (2) an unknown number of 

flowing artesian wells that continually discharge water from 

the aquifer, even when the water is unused, and (3) several 

small commercial facilities.

The unconfined aquifer in the study area has a greater 

potential for groundwater development than the confined 

aquifers. The unconfined aquifer in the eastern part of the 

study area receives more recharge than the confined aquifers 
34 Geohydrology & Water Quality of the Valley-Fill Aquifer System in the Town of Caroline, Tompkins County, New York

No data

Peak flow 1,490 

cubic feet per second

A

B

Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. 

2004

Oct. Nov. Dec. 

2003

0

200

400

600

800

1,000

1,200

0

200

400

600

800

1,000

1,200

Oct. Nov. Dec. Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. 

2002 2003

DISCHARGE, IN CUBIC FEET PER SECOND DISCHARGE, IN CUBIC FEET PER SECOND

Figure 18. Discharge for Sixmile Creek at Brooktondale, New York (U.S. Geological Survey streamgage Identification 

number 04233286) for (A) water year 2003, (B) water year 2004, (C) water year 2005, and (D) water year 2006.
Hydrology of the Valley-Fill Aquifer System 35

Peak flow 3,000 

cubic feet per 

second 

Peak 

flow

2,030 

cubic feet 

per 

second

Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. 

2006

Oct. Nov. Dec. 

2005

0

200

400

600

800

1,000

1,200

Peak flow 4,100 

cubic feet per second

0

200

400

600

800

1,000

1,200

Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. 

2005

Oct. Nov. Dec. 

2004

C

D

DISCHARGE, IN CUBIC FEET PER SECOND DISCHARGE, IN CUBIC FEET PER SECOND

Figure 18. Discharge for Sixmile Creek at Brooktondale, New York (U.S. Geological Survey streamgage Identification 

number 04233286) for (A) water year 2003, (B) water year 2004, (C) water year 2005, and (D) water year 2006.
36 Geohydrology & Water Quality of the Valley-Fill Aquifer System in the Town of Caroline, Tompkins County, New York

because it generally has greater permeability than the confined 

aquifers and readily receives recharge from several sources, 

including direct precipitation on land surface, losing tributary 

streams, and seepage of runoff from adjacent unchanneled 

hillsides. Therefore, the relatively large amounts of water that 

recharge the unconfined aquifer generally result in greater 

potential for large sustainable yields to pumping wells. Where 

the valley-fill aquifer is confined, the permeability of the 

aquifer sediments tend to be more variable (sand and gravel 

zones mixed with predominantly sand zones) and the amount 

of recharge is less. Therefore, the amount of water available to 

wells may be somewhat less in the confined aquifers than in 

the unconfined aquifer.

Table 1 provides the range, mean, and median of well 

yields and well depths for the unconfined, confined, and 

bedrock aquifer units in the study area. The data in the 

table were reported by water-well drillers except for the test 

wells drilled for this study, which were recorded by USGS 

personnel who logged the well. The well data were entered 

into the USGS National Water Information System (NWIS). 

In general, the reported yields of open-ended wells were 

somewhat greater for the unconfined sand and gravel aquifer 

(mean of 18 gal/min and median of 15 gal/min) than that for 

the confined aquifers (mean of 15 gal/min and median of 

12 gal/min). Bedrock wells generally had lower yields (mean 

of 8 gal/min and median of 6 gal/min) than the valley-fill 

aquifers. Yields from wells installed in the sand and gravel 

aquifers would be greater if they were constructed using well 

screens and properly developed.

Breaching of the Confining Unit at 

Slaterville Springs

In early July 1993, test boring and excavation work for 

an abutment at Buffalo Road Bridge in Slaterville Springs 

(fig. 13) breached the upper confining unit, which resulted 

in water from the confined aquifer discharging into the 

channel of Sixmile Creek. The breach of the confining unit 

released enough hydraulic pressure in the aquifer to cause 

several wells in the hamlet, which normally are under flowing 

artesian conditions, to stop flowing; this included the flowing 

artesian well at the Town Hall, 1,400 ft west of the bridge. 

As a result, water had to be supplied to several homes and 

businesses in the area. Bentonite pellets and a grout curtain 

were installed in the channel, which stopped the leak. A test 

well (TM 999, fig. 6) was installed on the streambank near 

the north end of the bridge on Aug. 8, 1993, to monitor water 

levels in the confined aquifer. The test well was screened from 

35.5 to 41 ft. Results of the test drilling indicated that the top 

of the confined aquifer was 35 ft below land surface from the 

top of the streambank, or about 22 ft below the streambed. 

Water levels were measured by personnel from the Tompkins 

County Public Works Department and the Town of Caroline 

Highway Department from August 8, 1993, to November 11, 

1994. Although water levels in the monitoring well were not 

measured until after the grout curtain was installed, the waterlevel measurements indicated that the head dropped more 

than 10 ft in the aquifer after the confining unit was breached 

(fig. 20). Then, after the grout was installed, the water level 

Sixmile Creek at Brooktondale

(upper Sixmile Creek basin)

Sixmile Creek at Bethel Grove

(lower Sixmile Creek basin)

64 percent base flow

(groundwater)

36 percent 

storm runoff

56 percent base flow

(groundwater)

44 percent 

storm runoff

Figure 19. Results of hydrograph-separation analyses for Sixmile Creek at Brooktondale, 

New York (upper Sixmile Creek basin), and Sixmile Creek at Bethel Grove, New York (lower 

Sixmile Creek basin), streamgages for the period 2003–07. Locations of streamgages are 

shown in figure 3.
Water Quality 37

rose for at least a month until it reached equilibrium (fig. 20), 

but it is unknown whether this equilibrium level represents 

static water level before the breach occurred because there 

were no water-level measurements made before the breach, 

and it took about a week after the monitoring well was 

installed (about 6 weeks since the breach had occurred) for 

the water level to recover to near static level (fig. 20) in the 

vicinity of the bridge.

This incident demonstrated that the hydraulic heads in 

the confined aquifer system are sensitive to large stresses, such 

as the introduction of a large pumping well or breaching of 

the confining unit by excavation or stream channel erosion. In 

addition, an accumulation of small, continuous stresses may 

also affect local groundwater levels in the confined aquifers. 

These small stresses may include (1) improperly finished 

wells that lack a proper seal, which enable water to escape 

from the aquifer around the outside of the casing, (2) wells in 

low areas of the valley that tap the confined aquifer and are 

allowed to continuously flow and drain into ditches (analogous 

to a perpetually flowing leaky faucet), and (3) an increase 

in residential development throughout the valley that has 

resulted in an increased withdrawal from the confined aquifers 

as a source of water. If enough of these small stresses were 

to occur, the result may be to lower the head in the confined 

aquifer system enough so that the low areas in the valley will 

cease to be under artesian flowing conditions. 

Water Quality

Water samples were collected to describe the chemical 

quality of groundwater and the base-flow component 

of surface water in the study area. For this study, nine 

groundwater samples were collected from wells finished 

in sand and gravel aquifers, and one from a well finished 

Land surface at top of streambank of Sixmile Creek at Buffalo Road bridge (elevation = 1,119.1 ft)

Land surface at Caroline Town Hall well (altitude = 1,109.0 ft)

Stream stage of Sixmile Creek at Buffalo Road bridge (altitude = 1,106.9 ft)

ALTITUDE, IN FEET ABOVE NATIONAL GEODETIC VERTICALDATUM OF 1929

DATE

6/1/93 10/1/93 02/1/94 06/1/94 10/1/94

1100

1105

1110

1115

1120

Figure 20. Hydrograph of groundwater levels in monitoring well TM 999 near bridge over Buffalo Road, from August 7, 1993, 

to November 7, 1994, Slaterville Springs, New York. Location of site is shown in figure 13.
38 Geohydrology & Water Quality of the Valley-Fill Aquifer System in the Town of Caroline, Tompkins County, New York

in bedrock. Ten surface-water samples were collected 

seasonally during base-flow conditions at the Sixmile Creek 

at Brooktondale streamgage (04233286) during the years 

2003–05, and 13 samples were collected during base-flow 

conditions at several selected tributaries to Sixmile Creek and 

West Branch Owego Creek during the years 2004–05. 

Where the valley-fill aquifer is unconfined in the study 

area, the surficial sediments are generally highly permeable 

and connected directly with the surface water; therefore, this 

part of the aquifer is vulnerable to immediate contamination 

from spills or improper disposal of liquids or soluble 

substances that could be leached into the aquifer. Conversely, 

in the part of the study area where the valley-fill aquifer is 

confined, a fine-grained sediment layer of low hydraulic 

conductivity restricts vertical flow between aquifer units.

Surface Water

Ten surface-water samples were collected by USGS 

personnel at roughly seasonal intervals during base-flow 

conditions at the Sixmile Creek at Brooktondale streamgage 

(04233286) during the years 2003–05 (table 2), and 

13 samples were collected during the years 2004–05 from 

4 tributaries in the study area (table 3). Samples were collected 

for analyses of nutrients, common ions, and inorganic 

constituents by the USGS National Water Quality Laboratory 

(NWQL) in Denver, Co. The location of surface-water 

sampling sites is shown in figure 21. 

Although base flow is an approximation of the 

chemical quality of groundwater, the concentrations of some 

constituents can be altered in the stream through contact with 

air and stream biota. For example, increased temperatures 

in the spring and summer result in an increase in microbial 

activity and algal growth in the streams, which can change 

dissolved oxygen concentrations, utilize the nitrogen in the 

water, and potentially cause decreased nitrate concentrations 

through denitrification if denitrifying bacteria are present. 

Therefore, base-flow quality under non-snowmelt conditions 

in winter, when temperatures are low and microbial activity 

and algal growth are minimal, provides the best approximation 

of the average chemical quality of shallow groundwater within 

the drainage area. 

Additional surface-water samples were collected 

during both base-flow and runoff periods from 2004 to 2006 

in the Sixmile Creek basin by a citizen’s volunteer group 

and analyzed for chemical, physical, and bacteriological 

indicators by the Community Science Institute (CSI), a 

nonprofit organization that operates a New York State 

Department of Health (NYSDOH) certified laboratory. 

The results of CSI chemical analyses can be found at 

http://www.communityscience.org/SixMile/sixmilecreek.html

(accessed October 14, 2008).

Physical Properties

The pH of the USGS collected surface-water samples 

(tables 2 and 3) ranged from 7.3 to 8.0; all of the 23 samples 

were within the accepted Secondary Maximum Contaminant 

Level (SMCL) range of 6.5 to 8.5 (U.S. Environmental 

Protection Agency, 2006). Specific conductance of the samples 

ranged from 121 to 426 microsiemens per centimeter (μS/cm) 

and dissolved oxygen concentrations (tables 2 and 3) ranged 

from less than 5.2 to 15.1 milligrams per liter (mg/L) .

Suspended sediment data were collected in Sixmile Creek 

at Brooktondale by the Tompkins County Soil and Water 

Conservation District to determine the load of sediment that 

is transported through this part of the basin, most of which 

ends up settling behind the silt dam above the Sixmile Creek 

reservoir in lower Sixmile Creek valley (fig. 3). This reservoir 

is the source of drinking water for the City of Ithaca, NY 

(fig. 3). Records of daily suspended sediment are available 

from the City of Ithaca Water Treatment Plant.

Common Inorganic Constituents

The major-ion composition of water from sampled 

streams and wells was evaluated using a Piper (trilinear) 

diagram (fig. 22). A Piper diagram (Piper, 1944) shows 

the relative contribution of major cations and anions, on a 

charge-equivalent basis, to the total ion content of the water. 

Percentage scales along the sides of the diagram indicate the 

relative concentration, in milliequivalents per liter, of each 

major ion. Cations are shown in the left triangle and anions 

are shown in the right triangle. The central diamond integrates 

the data.

Calcium dominates the cation composition and 

bicarbonate dominates the anion composition in most 

samples of base flow in the study area (fig. 22). In 

general, tributary samples were slightly more calciumbicarbonate rich than Sixmile Creek samples collected at 

Brooktondale and slightly less calcium-bicarbonate rich 

than groundwater samples (fig. 22). However, in general, 

water in all stream and groundwater samples was similar, 

except for groundwater samples from the two test wells at 

the Caroline Elementary School (TM 994 and TM1967), 

which suggests that the samples were collected in the streams 

during base-flow conditions and represent predominantly 

groundwater discharge. 

The base-flow samples collected from the tributary 

to Sixmile Creek at Route 79 bridge at Slaterville Springs, 

which drains the back side of the Valley Heads Moraine, 

and from the tributary in the north part of the aquifer near 

Midline Road (fig. 21) have relatively high concentrations 

of calcium bicarbonate (tables 2 and 3) because most of the 

water is derived from discharge from carbonate-rich sand and 

gravel that comprises much of the Valley Heads drift in the 

valley. Base flow that is derived primarily from groundwater 

that discharges from upland till and shale, such as the sample 

collected at the tributary to Willow Creek at New York 
Water Quality 39

Table 2. Physical properties and concentrations of inorganic constituents and nutrients in surface-water samples from Sixmile Creek at Brooktondale, New York, 2003–2005. [Sampling site location is shown in figures 3, 11A, and 21. USGS, U.S. Geological Survey; °C, degrees Celsius; mg/L, milligrams per liter; μS/cm, microsiemens per centimeter at 25°C; μg/L, micrograms per liter; <, less than; E, estimated value—constituent was detected in the sample but with low or inconsistent recovery]

USGS streamgage name

Sixmile 

Creek at 

Brooktondale

Sixmile 

Creek at 

Brooktondale

Sixmile 

Creek at 

Brooktondale

Sixmile 

Creek at 

Brooktondale

Sixmile 

Creek at 

Brooktondale

Sixmile 

Creek at 

Brooktondale

Sixmile 

Creek at 

Brooktondale

Sixmile 

Creek at 

Brooktondale

Sixmile 

Creek at 

Brooktondale

Sixmile 

Creek at 

Brooktondale

Date sampled 2/11/2003 5/20/2003 8/18/2003 1/13/2004 5/27/2004 6/28/2004 9/14/2004 11/16/2004 5/9/2005 7/19/2005

Streamgage identification number 04233286 04233286 04233286 04233286 04233286 04233286 04233286 04233286 04233286 04233286

Common ions Units Concentration of chemical constituents

Dissolved solids, at 180°C mg/L 173 142 176 146 130 201 142 154 178 213Fluoride, filtered mg/L <0.2 <0.17 <0.17 <0.17 <0.17 <0.17 <0.17 E0.06 E0.06 E0.08pH (field) pH 8.0 7.3 7.8 7.7 7.8 8.2 8.2 7.5 7.8 8.1Specific conductance (field) μS/cm 296 262 310 249 214 338 244 259 286 353Iron, filtered μg/L E9 22 15.3 14.2 36.6 10.6 12.1 12 15 <6Manganese, filtered μg/L 5 7 5.3 10.0 7.1 3.0 4.6 6.6 6.7 2.8Calcium, filtered mg/L 34 33 40.9 31.1 27.0 47.7 33.8 36.4 35.6 48.7Magnesium, filtered mg/L 6.3 6.2 7.25 5.89 4.79 7.79 5.44 6.92 6.48 8.20Silica, filtered mg/L 5.1 4.2 5.13 5.75 5.47 5.39 6.66 5.74 3.82 5.55Sodium, filtered mg/L 16 14 13.1 10.9 10.3 14.1 9.79 10.2 12.8 13.1Chlorides, filtered mg/L 32.8 25.1 22.1 19.9 15.6 23.5 13.7 15.8 24.6 23.3Sulfate, filtered mg/L 14.3 11.6 10.2 12.1 8.33 12.4 8.24 10.8 11.8 12.4Alkalinity, filtered CaCO3 mg/L 82 87 118 84 75 135 98 108 99 141Potassium, filtered mg/L 1.1 1.1 1.3 0.91 1.1 1.1 1.1 1.66 1.93 2.43

Nutrients

N, Nitrite, filtered mg/L <0.008 <0.008 <0.008 <0.008 E0.004 <0.008 <0.008 <0.008 <0.008 <0.008P, ortho-phosphate, filtered mg/L <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 E0.01 0.09 <0.02N as nitrate, NO2+NO3, filtered mg/L 0.801 0.296 0.265 0.782 0.306 0.465 0.367 0.485 0.517 0.344N, ammonia, filtered mg/L <0.04 <0.04 <0.04 <0.04 <0.04 <0.04 <0.04 <0.04 <0.04 <0.04N, organic+ammonia, filtered mg/L 0.2 E0.09 0.2 E0.08 0.2 E0.1 0.1 E0.1 0.2 0.3N, organic+ammonia, unfiltered mg/L 0.1 0.1 0.1 0.1 0.2 0.1 0.1 0.1 0.1 0.1Phosphorus, filtered mg/L 0.007 0.006 0.008 0.010 0.010 0.005 0.006 0.022 0.113 0.013Phosphorus, unfiltered mg/L 0.008 0.007 0.006 0.011 0.024 0.008 0.011 0.024 0.012 0.016
40 Geohydrology & Water Quality of the Valley-Fill Aquifer System in the Town of Caroline, Tompkins County, New York Table 3. Physical properties and concentrations of inorganic constituents and nutrients in surface-water samples from selected tributaries in upper Sixmile Creek basin and in West Branch Owego Creek basin, New York, 2004–2005. [Sampling site location is shown in figure 21. USGS, U.S. Geological Survey; Trib, tributary; °C, degrees Celsius; mg/L, milligrams per liter; μS/cm, microsiemens per centimeter at 25°C; μg/L, micrograms per liter; <, less than; E, estimated value—constituent was detected in the sample but with low or inconsistent recovery] USGS streamgage name Trib to Sixmile Creek at Ellis Hollow, Route 79 Trib to Sixmile Creek at Ellis Hollow, Route 79 Trib to Sixmile Creek at Ellis Hollow, Route 79 Trib to Sixmile Creek at Midline Valley, Route 79 Trib to Sixmile Creek at Midline Valley, Route 79 Trib to Sixmile Creek at Midline Valley, Route 79 Sixmile Creek at Six Hundred Road Sixmile Creek at Six Hundred Road Sixmile Creek at Six Hundred Road Willow Creek at Caroline, Route 79 Willow Creek at Caroline, Route 79 Trib to Sixmile Creek at Slater- ville Springs Date sampled 11/16/2004 5/9/2005 7/19/2005 11/16/2004 5/9/2005 7/19/2005 11/16/2004 5/9/2005 7/19/2005 11/16/2004 5/9/2005 7/19/2005 Fifteen-digit stream identification number 422340 076222801 422340 076222801 422340 076222801 422337 076212201 422337 076212201 422337 076212201 422359 076195801 422359 076195801 422359 076195801 422240 076171301 422240 076171301 422333 076203401 Common ions Units Concentration of chemical constituents Dissolved solids, at 180°C mg/L 179 190 223 187 196 244 106 140 154 72 70 226 Fluoride, filtered mg/L 0.12 E0.07 E0.09 E0.06 E0.07 E0.09 E0.05 <0.10 E0.07 <0.10 <0.10 E0.09 pH (field) pH 7.9 7.8 7.8 8.0 8.0 8.3 8.0 8.0 8.3 7.8 7.6 8.1 Specific conductance (field) μS/cm 293 298 362 299 326 413 182 205 263 117 115 395 Iron, filtered μg/L 93 24 11 7 7 <6 24 17 <6 E4 E3 48 Manganese, filtered μg/L 145 133 6.2 12.3 5.6 54.9 2.7 1.5 1.5 <0.6 E0.3 4.7 Calcium, filtered mg/L 41.2 38.9 52.2 45.8 46.9 61.3 25.4 26.4 37.2 13.5 11.4 53.8 Magnesium, filtered mg/L 8.52 7.99 10.8 8.88 9.11 11.3 5.38 5.49 7.07 3.01 2.57 11.4 Silica, filtered mg/L 7.63 5.09 7.14 6.57 4.03 6.70 5.87 4.05 3.33 4.15 4.02 7.33 Sodium, filtered mg/L 11.5 12.0 9.65 8.91 10.3 12.1 5.60 6.82 7.45 5.35 6.25 14.0 Chlorides, filtered mg/L 19.6 22.9 15.8 14.0 18.1 19.5 9.02 13.2 12.7 7.69 10.3 28.0 Sulfate, filtered mg/L 12.1 11.1 10.3 11.0 12.6 14.2 9.19 10.1 9.97 7.83 8.32 12.9 Alkalinity, filtered CaCO3 mg/L 121 113 113 140 135 183 76 75 113 39 30 151 Potassium, filtered mg/L 1.27 0.96 0.83 1.18 0.91 1.05 0.83 0.83 0.95 1.31 1.08 0.96 Nutrients N, Nitrite, filtered mg/L 0.008 0.033 <0.008 <0.008 <0.008 <0.008 <0.008 <0.008 <0.008 E0.004 <0.008 E0.004 P, ortho-phosphate, filtered mg/L <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 N as nitrate, NO2+NO)3, filtered mg/L 0.143 0.79 E0.054 0.477 0.541 0.144 0.185 0.172 0.060 0.435 0.302 1.91 N, ammonia, filtered mg/L 0.05 E0.04 <0.04 <0.04 <0.04 <0.04 <0.04 <0.04 <0.04 <0.04 <0.04 <0.04 N, organic+ammonia, filtered mg/L 0.2 0.2 0.2 0.1 0.1 0.2 E0.07 0.1 0.2 0.1 E0.07 0.2

N, organic+ammonia, unfiltered mg/L 0.3 0.2 0.2 0.1 0.1 0.2 E0.09 E0.08 E0.1 0.1 E0.08 0.3Phosphorus, filtered mg/L 0.008 0.010 0.017 0.012 0.008 0.007 0.007 0.004 0.004 0.006 0.006 0.008Phosphorus, unfiltered mg/L 0.025 0.033 0.033 0.016 0.006 0.010 0.009 0.006 0.006 0.007 0.009 0.017
Water Quality 41 Figure 21. Location of groundwater and surface-water sampling sites in upper Sixmile Creek valley and West Branch Owego Creek valley, Town of Caroline, New York.

Sixmile

Creek

Willow

Creek

West

Branch

Owego

Creek

76°17' 76°24'

42°25'

42°22'

TOWN OF DRYDENTOWN OF CAROLINE

TOWN OF RICHLAND

TOWN OF CAROLINE

TIOGA COUNTY

TOMPKINS COUNTY

TOWN OF CAROLINE

TOWN OF DRYDEN

0 1 MILE 0.50 1 KILOMETER 0.5

TM 987

TM 994

TM1967

TM2023

TM 988

TM 986

TM 990

TM1763

TM1494

TM 984

Base from U.S. Geological Survey, Seamless Data Distribution System, accessed in 2007 at http://seamless.usgs.gov Universal Transverse Mercator projection, Zone 18

X

Site of 

“DEER LICKS” 

historical

marker

Valley Road

Tributary to Sixmile Cr.

(nr Midline Rd.)

Ellis HollowTributary to Sixmile Creek

Sixmile Creek

Six Hundred Road

Tributary to Sixmile Creek

at Slaterville 

Springs 

Caroline 

Elementary School

Willow Creek

at Route 79

Sixmile Creek atBrooktondale

Base-flow sampling site at Sixmile Creek at Brooktondale streamgageBase-flow sampling sites at tributaries

EXPLANATION

Well and well site name in which groundwater sample wascollected from well finished in the valley-fill aquifer—Wellsite name is assigned by U.S. Geological Survey

TM 990

Well and well site name in which groundwater sample wascollected from well finished in a bedrock aquifer—Wellsite name is assigned by U.S. Geological Survey

TM 988

Boundary of valley-fill aquifer
42 Geohydrology & Water Quality of the Valley-Fill Aquifer System in the Town of Caroline, Tompkins County, New York

 0 

 100 

 80 

 60 

 40 

 20 

 100 

 80 

 60 

 40 

 20 

 0 

TM1967

TM 994

TM1967

TM 994

 0 

 0 

 20 

 40 

 60 

 80 

 100 100 

 80 

 60 

 40 

 20 

 0 

 100 

 80 

 60 

 40 

 20 

 0 

 0 

 20 

 40 

 60 

 80 

 100 

 0 

 20 

 40 

 60 

 80 

 100 

Magnesium

Sodium plus Potassium

Bicarbonate

Sulfate

Sulfate plus Chloride

Calcium plus Magnesium

Percent

Percent

 20 

 40 

 60 

 80 

 100 

Percent

Calcium Chloride

 0 100 

 80 

 60 

 40 

 20 

 0 

 20 

 40 

 60 

 80 

 100 

TM1967

TM 994

EXPLANATION

Groundwater sample and well site name—Site name

is assigned by the U.S. Geological Survey. Well record

is in Appendix 1 at end of report

Sixmile Creek at Brooktondale sample

Tributary sample

TM 994

Figure 22. Variability in major ion composition of surface water and groundwater in the lower Sixmile Creek and West 

Branch Owego Creek valleys, Town of Caroline, New York.
Water Quality 43

State Route 79 and Sixmile Creek at the abandoned bridge 

on Six Hundred Road (fig. 21), has lower concentrations of 

calcium bicarbonate because these deposits contain much less 

carbonate material than the sand and gravel deposits. 

Concentrations of most constituents in Sixmile Creek 

at Brooktondale were similar for all 10 rounds of samples 

collected from 2003 to 2005 except for concentrations of 

calcium and magnesium, which were detected at greater 

concentrations during the summer round of samples (tables 2 

and 3). The greater concentrations of calcium and magnesium 

in the summer samples likely reflect a difference in the source 

area that supplies the groundwater discharge to the streams. 

When evapotranspiration is minimal during winter and early 

spring, there is more young freshwater from precipitation 

that recharges the upper part of the stratified drift, which then 

discharges to the stream. Conversely, when evapotranspiration 

is greater during the summer, often exceeding the rate of 

precipitation, there is little recharge to the stratified drift. 

Therefore, the water that discharges locally into the streams 

consists of older water derived from deeper zones in the 

aquifer with longer flow paths and resident times that permit 

more mineralization.

Sodium and chloride concentrations are relatively low 

in all streams but increase somewhat downstream in Sixmile 

Creek between the sampling site at Six Hundred Road near 

Slaterville Springs and the sampling site at the Brooktondale 

streamgage (fig. 21). Some of the increase in sodium and 

chloride concentrations could be attributed to road salt, 

but most is probably natural discharge of brackish water 

originating from deep zones in bedrock that discharges 

upward; some of the brackish water enters the unconsolidated 

deposits in the valley, while some discharges to springs 

that eventually drain into Sixmile Creek. A spring, which 

originates on a hillside south of Valley Road and flows into 

one of the tributaries that drains to Sixmile Creek, was found 

to have a history of brackish water. This brackish spring is 

close to a historic highway marker (location shown in fig. 21) 

that attests to the origin of natural brackish water; the signage 

states “DEER LICKS—INDIANS AND EARLY SETTLERS 

HERE OBTAINED THEIR SALT” (fig. 23).

Nutrients

Base-flow samples collected during the years 2003–05 

were analyzed for several nitrogen species; the predominant 

species in all samples was nitrate (tables 2 and 3). Nitrogen 

is vital to the growth of vegetation, but too much nitrogen in 

streams, commonly derived from fertilizers and sewage, can 

cause excessive plant and algal growth. When this organic 

matter decomposes it can clog waterways, which depletes the 

oxygen in the water column that is needed by other aquatic 

life. Excessive nitrate in drinking water is also a human 

health concern; as a result, the U.S. Environmental Protection 

Agency (USEPA) has established 10 mg/L (as N) as the 

maximum contaminant level (MCL) (U.S. Environmental 

Protection Agency, 2006). The concentration of nitrate was 

less than 1.0 mg/L in all base-flow samples except in the 

tributary to Sixmile Creek at Slaterville Springs, NY, on 

July 19, 2005, when it was detected at 1.91 mg/L and on May 

5, 2005, the concentration was 1.97 mg/L. During the summer, 

this tributary receives groundwater that discharges from the 

Valley Heads Moraine, which is overlain by large amounts of 

agriculture areas. 

Concentrations of nitrate are lowest in the summer 

samples, which likely are the result of nitrogen uptake by 

vegetation and microbial activity in the streams. Higher nitrate 

concentrations in winter samples relative to summer samples 

can be attributed to seasonal decreases in plant growth and 

microbial activity in the streams during the winter, which 

allows nitrate to persist in the stream. 

Groundwater

Groundwater samples were collected from 10 wells 

(8 finished in confined sand and gravel aquifers, 1 finished 

in an unconfined aquifer, and 1 finished in bedrock (fig. 21). 

Field measurements were made of pH, specific conductance, 

and water temperature. Samples were collected for analyses 

of nutrients, common ions, and inorganic constituents by the 

USGS NWQL in Denver, Colo. Several samples were also 

collected for analyses for groundwater age dating by the 

USGS Chlorofluorocarbon Laboratory in Reston, Va. 

Figure 23. The Deer Licks historic highway marker 

along the side of Valley Road, Town of Caroline, New York.
44 Geohydrology & Water Quality of the Valley-Fill Aquifer System in the Town of Caroline, Tompkins County, New York

Physical Properties

The pH of the groundwater samples (table 4) ranged 

from 6.5 to 8.0, specific conductance of the samples ranged 

from 216 to 807 μS/cm and dissolved oxygen concentrations 

(tables 2 and 3) ranged from less than 0.19 to 6.0 mg/L. Well 

TM1494, which was the only well that was finished in the 

unconfined aquifer, produced water with the highest dissolvedoxygen concentration.

Common Inorganic Constituents

Results of the groundwater sample analyses indicate 

that the water is generally of good quality, potable, and 

predominantly a calcium-bicarbonate type, except for 

groundwater samples from wells TM 994 and TM1967 

where the composition becomes more dominated by 

sodium and chloride than the other groundwater samples 

(fig. 22). The cation that was typically detected in the highest 

concentration was calcium, ranging from 25.8 to 80.1 mg/L 

(table 4). Sodium values ranged from 2.61 to 106 mg/L, and 

two samples (TM 994 and TM1967) exceeded the USEPA 

Drinking Water Advisory for sodium, which recommends that 

sodium concentrations in drinking water do not exceed 30 to 

60 mg/L on the basis of taste (U.S. Environmental Protection 

Agency, 2006). Silica values ranged from 5.76 to 13.7 mg/L. 

The SMCL for iron (300 micrograms per liter, μg/L) was 

exceeded in one sample, while the SMCL for manganese 

(50 μg/L) was exceeded in six samples (table 4).

Variations in sodium concentrations were probably due to 

either enrichment through road de-icing salts or from brackish 

water in bedrock that locally discharges to the valley fill. The 

brackish water that discharges from the spring along Valley 

Road presumably discharges to the valley-fill aquifers where 

bedrock is in contact with the aquifer beneath the valley and 

is probably responsible for the relatively high concentrations 

of sodium that were detected in wells in the eastern part of 

the study area. Although the New York State Department of 

Health (2008) has no designated limit on the recommended 

MCL of sodium, they do warn that water containing more 

than 20 mg/L of sodium should not be consumed by people on 

severely restricted sodium diets, and water containing more 

than 270 mg/L of sodium should not be consumed by people 

on moderately restricted sodium diets. The taste threshold 

(concentration at which the majority of consumers do not 

notice an adverse taste in drinking water) for sodium ranges 

from 30 to 60 mg/L (New York State Department of Health, 

2008) and was exceeded in two samples collected from test 

wells TM994 and TM1967 at the Caroline Elementary School.

The anion that was detected in the greatest concentrations 

was bicarbonate, while chloride and sulfate generally were 

detected in lesser concentrations. Bicarbonate values ranged 

from 89 to 229 mg/L calcium carbonate (table 4) and were 

calculated from the filtered alkalinity concentrations that 

ranged from 70 to 188 mg/L (table 4). Chloride values 

ranged from 1.18 to 148 mg/L. Sulfate values ranged from 

2.06 to 32.2 mg/L and did not exceed the SMCL of 250 mg/L.

In general, the chemistry of inorganic constituents in the 

groundwater and surface-water (base-flow) samples is similar 

(fig. 22), confirming that the surface-water samples that were 

collected during base-flow conditions were representative of 

groundwater discharge. There were some exceptions, however, 

such as sodium and chloride, which were found at elevated 

concentrations in two wells that were sampled, likely due to 

discharge of brackish water from underlying bedrock units.

Nutrients

Groundwater samples collected during the years 2004–05 

were analyzed for several nitrogen species; concentrations 

of nitrate were generally low. In five of the nine samples 

collected from the valley-fill aquifer, nitrate was below 

the detection limit of 0.060 mg/L, and the four remaining 

concentrations ranged from 0.339 to 2.68 mg/L (table 4); 

the MCL was not exceeded in any of the samples. Water 

sampled from well TM1494 (fig. 21), which is finished in the 

unconfined aquifer in the eastern part of the study area, had 

the highest nitrate concentration of 2.68 mg/L. Unconfined 

aquifers are more susceptible to contamination because the 

chemicals applied on land surface readily seep to the water 

table where they can easily enter wells. The sampled wells that 

were finished in confined aquifers had nitrate concentrations 

that were below the detection limit or less than 0.50 mg/L. 

Although most water withdrawn from wells is returned to 

the groundwater through septic systems, most septic effluent 

probably flows through the shallow groundwater system 

and eventually discharges to streams rather than making its 

way to the confined aquifers. The confining units restrict the 

movement of shallow groundwater, including that which 

contains effluent from septic systems, from entering the 

confined aquifer units.

Groundwater Age Dating

Concentrations of CFCs and 3H can be used to estimate 

the age of groundwater (table 5). CFCs are synthetic industrial 

compounds that have been released into the atmosphere 

since the mid-1940s and are found in precipitation. 

CFC concentrations in precipitation, and those found in 

groundwater recently derived from precipitation, correspond to 

that found in the contemporaneous atmosphere. Atmospheric 

CFC concentrations have been recorded since about 1945 

(Plummer and Busenberg, 2000). Therefore, comparison of 

CFC concentrations in a water sample to historical records of 

atmospheric CFC concentrations can indicate the year (post1945) in which the water entered the water table. However, the 

estimated age of a groundwater sample can also reflect mixing 

of older and younger water within an aquifer. 

Recharge temperature is an important component 

in the interpretation of the age of the water, along with 
Water Quality 45

Table 4. Physical properties, and concentrations of inorganic constituents and nutrients in groundwater samples from upper Sixmile Creek and West Branch Owego Creek valley, 2004–2005. [Sampling site location is shown in figure 21. USGS, U.S. Geological Survey; Elem sch, elementary school; °C, degrees Celsius; mg/L, milligrams per liter; μS/cm, microsiemens per centimeter at 25°C; μg/L, micrograms per liter; ft, feet; <, less than; E, estimated value; S&G, sand and gravel; conf, confined; unconf, unconfined; constituent was detected in the sample but with low or inconsistent recovery]

Local name Town Hall Elem sch Elem sch

USGS well-site name TM 986 TM 984 TM 987 TM 990 TM1494 TM1763 TM 994 TM1967 TM2023 TM 988

Date sampled 11/30/2004 11/30/2004 11/30/2004 12/1/2004 11/30/2004 11/30/2004 7/18/2005 7/18/2005 8/17/2005 11/30/2004

Fifteen-digit well-site number 422339 

076205901

422331 

076235601

422320 

076233601

422327 

076223401

422242 

076173501

422333 

076202801

422336 

76221302

422336 

76221301

422344 

076192901

422258

076224301

Common ions Units Concentration of chemical constituents

Dissolved solids, at 180°C mg/L 154 249 218 326 118 176 410 416 151 177Fluoride, filtered mg/L 0.14 0.12 0.10 E0.1 <0.10 E0.08 E0.08 0.28 E0.07 0.1pH (field) pH 7.5 7.6 7.6 7.4 6.5 7.6 7.8 7.5 7.8 7.1Specific conductance (field) μS/cm 250 450 367 615 216 316 718 774 261 319Iron, filtered μg/L 46 955 88 72 16 E5 175 109 42 E5Manganese, filtered μg/L 183 116 159 161 1.5 9.5 239 105 20.6 3.4Calcium, filtered mg/L 36.9 63.7 58.5 80.1 25.8 48.5 68.7 37.1 40.2 45.2Magnesium, filtered mg/L 6.80 13.6 9.09 15.4 5.01 10.1 16.4 7.58 7.15 8.54Silica, filtered mg/L 13.7 12.1 13.5 9.53 5.76 7.79 9.90 8.14 7.49 9.73Sodium, filtered mg/L 5.84 9.8 4.98 27.2 7.97 2.61 52 106 4.32 6.60Chlorides, filtered mg/L 2.45 24.8 9.23 54.0 9.65 1.18 112 148 1.76 10.7Sulfate, filtered mg/L 18.3 32.2 30.5 25.1 10.8 22.7 28.3 2.06 17.5 12.7Alkalinity, filtered CaCO3, (field) mg/L 96 119 120 170 47 100 146 144 88 94Potassium, filtered mg/L 0.79 0.79 0.50 1.09 0.89 0.68 0.97 0.68 0.67 0.57

Nutrients

N, Nitrite, filtered mg/L <0.008 <0.008 <0.008 <0.008 <0.008 <0.008 0.009 <0.008 0.04 <0.008P, ortho-phosphate, filtered mg/L <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 E0.01 <0.02 <0.02N as nitrate, NO2+NO3, filtered mg/L <0.060 <0.060 <0.060 <0.060 2.68 0.339 0.354 <0.060 0.538 0.585N, ammonia, filtered mg/L 0.09 <0.04 0.04 <0.04 <0.04 <0.04 0.25 0.25 0.18 <0.04N, organic+ammonia, filtered mg/L 0.1 <0.1 E0.09 0.1 E0.07 <0.1 E0.03 0.4 0.3 E0.09N, organic+ammonia, unfiltered mg/L 0.1 <0.1 0.1 <0.1 E0.05 <0.1 E0.08 0.6 0.2 E0.08Phosphorus, filtered mg/L 0.008 <0.004 E0.002 0.009 0.007 <0.004 E0.003 0.035 E0.003 E0.002Phosphorus, unfiltered mg/L 0.009 E0.003 0.005 0.004 0.009 <0.004 0.008 0.19 0.006 0.009

Physical properties Values of physical properties

Well depth below land surface ft E40 50 40 60 29 40 39 92 114 E100Aquifer type S & G, conf S & G, conf S & G, conf S & G, conf S & G, uconf S&G, unconf S & G, conf S & G, conf S & G, conf ShaleWater temperature °C 10.2 10.2 10.2 10.4 9.5 10.1 11.8 12.3 11.5 9.6Tritium, unfiltered TU 5.56 10.1 0.81
46 Geohydrology & Water Quality of the Valley-Fill Aquifer System in the Town of Caroline, Tompkins County, New York

concentrations of CFCs (Heaton, 1981; Heaton and Vogel, 

1981; Stute and Schlosser, 1999). The recharge temperatures 

calculated for water from three wells ranged from 7.1 to 8.2°C 

(table 5). 

Tritium (3H) is a radioactive isotope of hydrogen with a 

half-life of 12.32 years (Lucas and Unterweger, 2000). Based 

on releases to the atmosphere from nuclear testing, 3H can be 

used as a tracer to estimate whether groundwater has been 

recharged before or after 1953. The standard unit of measure 

for 3H is a 3H unit (TU) for which 1 TU is equivalent in terms 

of radioactivity to 3.2 pCi/L (Clark and Fritz, 1997). The 

greatest concentrations of 3H (greater than 500 TU) occurred 

following periods of atmospheric testing of nuclear weapons 

that began in 1952 and peaked in 1963–64 (Clark and Fritz, 

1997). Atmospheric concentrations have gradually declined 

since 1963–64 and present-day groundwater typically contains 

less than 1 to 10 TU (Clark and Fritz, 1997). Natural (prenuclear age) levels of 3

H in precipitation are on the order of 

1 to 5 TU. The relative age of the groundwater (time since it 

entered the aquifer and ceased contact with the atmosphere) 

can be estimated through a comparison of the 3H concentration 

in a water sample with the recorded historical changes 

in concentration in the atmosphere, taking into account 

consideration the half-life decay. Concentrations of 3H in 

the three groundwater samples ranged from 0.8 to 10.2 TU 

(table 5). Groundwater that does not contain detectable 3H 

(less than 0.8 TU) can be assumed to have been recharged 

prior to 1953, and groundwater that does contain detectable 

3

H (more than 0.8 TU) is assumed to contain some component 

of groundwater that was recharged after 1953 (Cordy and 

others, 2000). The 3H concentrations were used along with 

concentrations of CFCs to estimate the apparent age of 

groundwater (table 5).

Table 5. Data on apparent groundwater ages from groundwater samples collected from three wells that tap the confined valley-fill 

aquifers in upper Sixmile Creek valley, Town of Caroline, New York.

[CFC, chlorofluorocarbon, pptv, parts per trillion; 3H, tritium; USGS, U.S. Geological Survey]

 Sample site Sampling 

date

Calculated 

atmospheric 

mixing ratio, 

pptv, CFC-12

Model 

piston 

dates 

for CFC-12

3

H

units

Estimated 3

H

age

Comments

TM 986 Caroline Town Hall well 11/30/2004 7.31

4.69

6.46

1950

1948

1949

5.6 Late 1950s Early to late 1950s.

TM 994 USGS test well at Caroline 

Elementary School (depth = 39 ft)

7/18/2005 124.54

127.64

 1972

1972

10.2 Early 1970s 

or younger

Early 1970s or 

younger. Possible 

mixture.

TM1967 USGS test well at Caroline 

Elementary School (depth = 92 ft)

7/18/2005 19.83

24.91

22.61

1958.5

1960

1959.5

0.8 Early 1950s Early to late 1950s.

Three samples were collected and analyzed for CFCs, 

dissolved gases, and 3H to estimate the age of the groundwater 

in the study area. One sample was collected on November 

30, 2004, from the flowing artesian well (TM 986) at the 

Caroline Town Hall, and two samples were collected on July 

18, 2005, at the USGS nested pair of test wells (TM 994 and 

TM1967) at the Caroline Elementary School (fig. 21). The 

results of the age-dating samples are given in table 5. The 

CFC and 3H samples indicate that the apparent age of the 

water was early to late 1950s from the flowing well at the 

Town Hall, early-to-late 1970s in the shallow test well (39 

ft deep) at the elementary school, and early-to-late 1950s 

from the deep test well (TM1967) at the elementary school. 

Relatively low concentrations of CFCs and a low 3H value of 

0.8 TU measured in the deep well (TM1967) at the elementary 

school, as well as relatively high concentrations of sodium and 

chloride (that are probably derived, for the most part, from 

brackish water discharging from bedrock into the valley-fill 

aquifer) indicate that water in the basal confined aquifer is 

relatively old (50 years or more). The water in this well is 

probably a mixture of older (pre-1950s) bedrock water and 

some younger (post-1950s) water from recharge that has 

either travelled through the unconsolidated deposits via long 

flow paths or moved vertically (extremely slowly) through 

confining units. Water from the shallow test well (TM 994, 

finished in the upper confined aquifer) at the elementary 

school had higher concentrations of CFCs than the deeper 

test well (TM1967, finished in the basal confined aquifer) at 

the school, and at the Town Hall well (TM 986, finished in 

the basal confined aquifer). Also, test well TM 994 had a 3H 

value of 10.2 TU (table 5, samples with values between 5 and 

15 TU indicate that the water probably entered the aquifer 

sometime after 1970). Additionally, in well TM 994, analyses 
Summary 47

showed trace amounts of nitrate and elevated concentrations of 

sodium and chloride (but only about half that of the deep test 

well)—all of which suggest that the water from the shallow 

well TM 994 is a mixture of mostly relatively young water 

(probably from 1990s and younger) with some older brackish 

water that is slowly seeping upward from deep zones in the 

bedrock and through the confining bed that separates the two 

aquifers. The Caroline Town Hall well (TM 986) had the 

lowest concentrations of CFCs (table 5) that were analyzed, 

but it had a higher 3H unit value (5.56 TU) than the deep test 

well TM1967, which suggests that this water is also a mixture 

of recent (1952–2003) water and older water (pre-1952).

The results of the apparent ages can be used as clues to 

determining the sources of recharge to the aquifers. Older 

water (such as that found in the deep test well TM1967) is 

indicative of an aquifer that is sealed off from nearby shallow 

sources of recharge and derives most of its water from either 

slow infiltration through the overlying confining unit or lateral 

groundwater inflow from bedrock along the valley walls and 

valley floor. Conversely, relatively young water (such as that 

found in well TM 994 finished in the upper confined aquifer) 

suggests that the sources of recharge are nearby, such as where 

the confined aquifer crops out at land surface locally along the 

valley walls.

Summary

In 2002, the U.S. Geological Survey, in cooperation 

with the Town of Caroline and Tompkins County Planning 

Department, began a study of the valley-fill aquifer in upper 

Sixmile Creek and headwaters of West Branch Owego 

Creek valleys in the Town of Caroline, NY Confined sand 

and gravel units form the major aquifers in the western and 

central portions of the upper Sixmile Creek valley, and an 

unconfined sand and gravel unit forms the major aquifer in the 

eastern portion of the upper Sixmile Creek valley and in the 

headwaters of the West Branch Owego Creek valley. 

East-west trending valleys such as upper Sixmile Creek 

valley that act as tributaries to north-south trending deep 

troughs (lower Sixmile Creek valley) were not oriented 

parallel to the direction of ice movement and thus underwent 

less intensive glacial scouring, which resulted in less deeply 

eroded valleys than the north-south trending valleys. These 

east-west trending tributary valleys end high above the floor of 

the north-south troughs they join and are known as “hanging 

valleys.” The valley-fill deposits thin along the edges of the 

valley where till-mantled bedrock crops out along the valley 

walls. The thickness of the valley fill in the thalweg, or deepest 

part of the valley, is a little over 100 feet (ft) in the west part 

of the study area and is greater than 165 ft in the central and 

eastern parts of the valley.

A groundwater divide at the Valley Heads Moraine 

separates groundwater that flows westward through upper 

Sixmile Creek valley into the Great Lakes basin from 

groundwater that flows eastward into the Susquehanna 

River basin. Groundwater in the upper and basal confined 

aquifers are under artesian conditions everywhere except at 

the discharge area in the western end of the upper Sixmile 

Creek valley where groundwater discharges to springs and 

to streams. Principal sources of recharge to the two confined 

aquifers are likely from (1) the side of the valley where the 

confined aquifers may extend up along the flanks of the 

bedrock valley walls and crop out at land surface, or are in 

contact with coarse-grained deltaic and fluvial sediments, 

both of which constitute an avenue for direct precipitation and 

seepage losses from tributary streams to recharge the aquifers; 

or (2) adjacent fine-grained sediment and bedrock where the 

buried aquifers are isolated from overlying permeable deposits 

by confining units and receive lesser amounts of recharge.

Most groundwater withdrawals from the valley-fill 

aquifers are from open-ended, 6-inch-diameter casings, with 

lesser amounts withdrawn from shallow dug wells and from 

cisterns that collect groundwater discharged from springs 

(especially in the Brooktondale, NY, area). The valley-fill 

aquifer is the source of water for about 200 households, 

several apartment complexes, two mobile home parks, 

a school, and several farms and small businesses. About 

750 people rely on groundwater from the valley-fill aquifers as 

a source of drinking water.

In general, the reported yields were somewhat greater for 

the unconfined sand and gravel aquifer (mean of 18 gallons 

per minute (gal/min) and median of 15 gal/min) than for the 

confined aquifers (mean of 15 gal/min and median of 12). 

Bedrock wells generally had lower yields (mean of 8 gal/min 

and median of 6 gal/min) than wells finished in the valley-fill 

aquifers. The respective mean and median well depths for the 

various aquifer types were: 42 ft and 35 ft for the unconfined 

sand and gravel aquifer, 64 ft and 57 ft for the confined sand 

and gravel aquifers, and 149 ft and 135 ft for bedrock aquifers.

During the years 2003–05, 10 surface-water samples 

were collected at roughly seasonal intervals during base-flow 

conditions at the U.S. Geological Survey Sixmile Creek at 

the Brooktondale streamgage site; several samples were also 

collected from four tributaries in the study area. In the Sixmile 

Creek samples, the predominant cation detected was calcium, 

with moderate amounts of magnesium and silica; the major 

anions were bicarbonate, chloride, and sulfate. Sodium and 

chloride concentrations were relatively low in all streams 

sampled but increased downstream in Sixmile Creek. Some 

of the increase in sodium concentration may be attributed to 

road salt, but most is likely natural discharge of brackish water 

originating from deep zones in the bedrock, which discharges 

upward into the valley-fill aquifers. The concentration of 

nitrate was less than 1.0 milligram per liter (mg/L) in all 

base-flow samples except in the tributary to Sixmile Creek at 

Slaterville Springs, NY; on July 19, 2005, the concentration 

was 1.91 mg/L and on May 5, 2005 the concentration was 

1.97 mg/L. During the summer, this tributary originates from 

groundwater discharging from the Valley Heads Moraine, 

which is overlain by large amounts of agriculture.
48 Geohydrology & Water Quality of the Valley-Fill Aquifer System in the Town of Caroline, Tompkins County, New York

Groundwater samples were collected from 10 wells, 9 

that were finished in sand and gravel aquifers and 1 finished 

in bedrock. Field measurements were made of pH, specific 

conductance, dissolved oxygen, and water temperature, 

and samples were also collected for laboratory analyses of 

nutrients, common inorganic constituents, and groundwater 

age dating. Results of the groundwater sample analyses 

indicate that the water is predominantly a calcium-bicarbonate 

type. The cation that was detected in the highest concentration 

was calcium, which ranged from 25.8 to 80.1 mg/L. Sodium 

values ranged from 2.61 to 106 mg/L, and two samples 

exceeded the U.S. Environmental Protection Agency Drinking 

Water Advisory of 30 to 60 mg/L. Sodium concentrations 

likely varied due to either local enrichment through road 

de-icing salts or from brackish water in bedrock discharging to 

the unconsolidated valley fill in some places. Concentrations 

of nitrate were generally low. In five of the nine samples 

collected from the valley-fill aquifer, nitrate was below the 

detection limit of 0.060 mg/L, and concentrations ranged 

from 0.239 to 2.68 mg/L in the four wells that were above the 

detection limit.

Three wells (Caroline Town Hall well TM 986 and 

two test wells drilled at the Caroline Elementary School, 

TM 994 and TM1967) were sampled and analyzed for 

chlorofluorocarbons, dissolved gases, and 3H to estimate 

the age of groundwater in the study area. The results of the 

chlorofluorocarbons and 3H sample analyses indicate that the 

apparent age of the groundwater was early to late 1950s from 

the flowing well at the Town Hall, early to late 1970s in the 

shallow test well (39 ft deep) at the elementary school, and 

early to late 1950s from the deep test well (TM1967) at the 

elementary school.

References Cited

Buchanan, T.J., and Somers, W.P., 1982, Stage measurement 

at gaging stations (Chapter A7): U.S. Geological Survey, 

Techniques of Water-Resources Investigations of the 

United States Geological Survey, Book 3, Applications of 

Hydraulics, 28 p.

Busenberg, E., and Plummer, L.N., 1992, Use of 

chlorofluorocarbons (CCl3F and CCl2F2) as hydrologic 

tracers and age-dating tools—The alluvium and terrace 

system of Central Oklahoma: Water Resources Research, 

v. 28, no. 9, p. 2257–2283.

Cadwell, D.H., 1972, Late Wisconsinan deglaciation 

chronology of the Chenango River valley and vicinity, New 

York: Binghamton, State University of New York, Ph.D. 

dissertation, 102 p.

Clark, I.D., and Fritz, Peter, 1997, Identifying and dating 

modern groundwaters, in Clark, I.D., and Fritz, Peter, eds., 

Environmental isotopes in hydrogeology: New York, Lewis 

Publishers, p. 172–196.

Clayton, K.M., 1965, Glacial erosion in the Finger 

Lakes region (New York State, USA): Zeitschrift fur 

Geomorphologie, NF9, p. 50–62.

Cordy, G.E., Gellenbeck, D.J., Gebler, J.B., Anning, D.W., 

Coes, A.L., Edmonds, R.J., Rees, J.A.H., and Sanger, H.W., 

2000, Water quality in the central Arizona basins, Arizona, 

1995–98: U.S. Geological Survey Circular 1213, 38 p.

Cressey, G.B., 1966, Land forms, in Thompson, J.H., ed., 

Geography of New York State: Syracuse University Press, 

fig. 9, p. 26.

Fleisher, P.J., 1986, Glacial geology and late Wisconsinan 

stratigraphy, upper Susquehanna drainage basin, New York, 

in Cadwell, D.H., ed., The Wisconsinan stage of the First 

Geological District, eastern New York: New York State 

Museum Bulletin 455, p. 121–142.

Fleisher, P.J., 1991, Active and stagnant ice retreat—

Deglaciation of central New York, in Ebert, J.R., ed., Field 

trip guidebook: Oneonta, State University of New York, 

New York Geological Association, Department of Earth 

Sciences, 63rd Annual Meeting, p. 307–371.

Fullerton, D.S., 1980, Preliminary correlation of post-Erie 

interstadial events (16,00–10,000) radiocarbon years before 

present), central and eastern Great Lakes region, and 

Hudson, Champlain, and St. Lawrence lowlands, United 

States and Canada: U.S. Geological Survey Professional 

Paper 1089, 52 p.

Haeni, F.P., 1988, Application of seismic-refraction techniques 

to hydrologic studies: U.S. Geological Survey Techniques 

of Water-Resources Investigations, book 2, chap. D2, 86 p.

Heaton, T.H.E., 1981, Dissolved gases—Some applications 

to groundwater research: Transactions of the Geological 

Society of South Africa, v. 84, p. 91–97.

Heaton, T.H.E., and Vogel, J.C., 1981, "Excess air" in 

groundwater: Journal of Hydrology, v. 50, p. 201–216.

Hutson, S.S., Barber, N.L., Kenny, J.F., Linsey, K.S., Lumia, 

D.S., and Maupin, M.A., 2000, Estimated use of water in 

the United States in 2000: U.S. Geological Survey Circular 

1268, 52 p.

Kappel, W.M., and Miller, T.S., 2003, Hydrogeology of the 

Tully Trough—Southern Onondaga County and northern 

Cortland County, New York: U.S. Geological Survey 

Water-Resources Investigations Report 03–4112, 16 p.
References Cited 49

Kappel, W.M., Miller, T.S., and Hetcher, K.K., 2001, 

Hydrogeology of the Tully Lakes area in southern 

Onondaga and northern Cortland Counties, New York: U.S. 

Geological Survey Water-Resources Investigations Report 

01–4166, 16 p.

Kennedy, E.J., 1990, Levels at streamflow gages: U.S. 

Geological Survey Techniques of Water-Resources 

Investigations, book 3, chap. A19, 39 p.

Kontis, A.L., Randall, A.D., and Mazzaferro, D.L., 2004, 

Regional hydrology and simulation of flow of stratified-drift 

aquifers in the glaciated northeastern United States: U.S. 

Geological Survey Professional Paper 1415–C, 156 p.

Ku, H.F.H., Randall, A.D., and MacNish, R.D., 1975, 

Streamflow in the New York part of the Susquehanna River 

basin: New York State Department of Environmental 

Conservation Bulletin 71, 130 p.

Lucas, L.L., and Unterweger, M.P., 2000, Comprehensive 

review and critical evaluation of the half-life of Tritium: 

Journal of Research of the National Institute Standards and 

Technology, v. 105, no. 4, p. 541–C, 549.

MacClintock, Paul, and Apfel, E.T., 1944, Correlation of the 

drifts of the Salamanca re-entrant, New York: Geological 

Society America Bulletin, v. 55, p. 1143–1164.

Mickelson, D.M., Clayton, L., Fullerton, D.S., and Borns, 

H.W., Jr., 1983, The late Wisconsin glacial record in the 

United States, in Wright, H.E., Jr., ed., Late Quaternary 

environments of the United States; v. 1, The Late 

Pleistocene: Minneapolis, University of Minnesota Press, 

p. 3–37.

Miller, T.S., 2000, Unconsolidated aquifers in Tompkins 

County, New York: U.S. Geological Survey WaterResources Investigations Report 00–4211, 1 plate.

Miller, T.S., Bugliosi, E.F., Reddy, J.E., 2008, Geohydrology 

of the unconsolidated valley-fill aquifer in the Meads 

Creek valley, Schuyler and Steuben Counties, New York: 

U.S. Geological Survey Scientific Investigations Report 

2008–5122, 33 p.

Miller, T.S., and Randall, A.D., 1991, Hydrogeology of 

glacial drift in through valleys near Dryden and Cortland, 

New York, in Ebert, J.R., ed., Guidebook for field trips, 

63rd Annual Meeting, New York Geological Association: 

Oneonta, State University of New York, p. 463–488.

Miller, T.S., Sherwood, D.A., Jeffers, P.M., and Mueller, 

Nancy, 1998, Hydrology, water-quality, and simulation 

of groundwater flow in a glacial aquifer system, Cortland 

County, New York: U.S. Geological Survey WaterResources Investigations Report 96–4255, 84 p.

Miller, T.S., and Staubitz, W.W., 1985, Hydrogeologic 

appraisal of five selected aquifers in Erie County, 

New York: U.S. Geological Survey Water-Resources 

Investigations Report 84–4334, 89 p.

Muller, E.H., and Cadwell, D.H., 1986, Surficial geologic map 

of New York, Finger Lakes sheet: New York State Museum 

and Chart Series 40, scale 1:250,000.

Mullins, H.T., and Hinchey, E.J., 1989, Erosion and infill of 

New York Finger Lakes—Implications for Laurentide ice 

sheet deglaciation: Geology, v. 17, p. 622–625.

Neeley, J.A., 1961, Soil survey of Tomkins County, New York: 

U.S. Department of Agriculture in cooperation with Cornell 

University Agricultural Experiment Station, Series 1961, 

no. 25, 241 p.

New York State Department of Health, 2008, Individual water 

supply wells—Fact Sheet 3: accessed December 22, 2008, 

at http://www.health.state.ny.us/environmental/water/

drinking/part5/append5b/fs3_water_quality.htm.

Northeast Regional Climate Center at Cornell University, 

New York: accessed November 2007, at http://climod.nrcc.

cornell.edu.

Olcott, Perry, 1995, Groundwater atlas of the United States, 

Connecticut, Maine, Massachusetts, New Hampshire, New 

York, Rhode Island, Vermont: U.S. Geological Survey 

Hydrologic Atlas 730–M.

Ostlund, H.G., and Werner, E., 1962, The electrolytic 

enrichment of tritium and deuterium for natural tritium 

measurements, in Tritium in the physical and biological 

sciences: Vienna International Atomic Energy Agency, 

v. 1, p. 95–104.

Piper, A.M., 1944, A graphic procedure in the geochemical 

interpretation of water analyses: American Geophysical 

Union Transactions, v. 25, p. 914–923.

Plummer, N.L., and Busenberg E., 2000, Chlorofluorocarbons, 

in Cook, P.G., and Herczeg, A.L., eds., Environmental 

tracers in subsurface hydrology: Boston, Kluwer, 

p. 441–478.

Plummer, L.N., Michael, R.L., Thurman, E.M., and Glynee, 

P.D., 1993, Environmental tracers for age dating young 

groundwater, in Alley, W.M., ed., 1993, Regional 

groundwater quality: New York, Van Nostrand Reinhold, 

p. 255–294.

Randall, A.D., 1978, Infiltration from tributary streams in 

the Susquehanna River basin, New York: U.S. Geological 

Survey Journal of Research, v. 6, no. 3, p. 285–297.
50 Geohydrology & Water Quality of the Valley-Fill Aquifer System in the Town of Caroline, Tompkins County, New York

Randall, A.D., 1981, Hydrology in relation to glacial geology 

along the Susquehanna River valley, Binghamton to Owego, 

New York, in Enos, Paul, ed., Guidebook for field trips in 

south-central New York: Binghamton, New York State 

Geological Association, 53d Annual Meeting, p. 147–170.

Randall, A.D., 2001, Hydrogeologic framework of stratifieddrift aquifers in the glaciated northeastern United States: 

U.S. Geological Survey Professional Paper 1415–B, 179 p.

Randall, A.D., Snavely, D.S., Holecek, T.P., and Waller, R.M., 

1988, Alternative sources of large seasonal groundwater 

supplies in the headwaters of the Susquehanna River basin, 

New York: U.S. Geological Survey Water-Resources 

Investigations Report 85–4127, 121 p.

Reilly, T.E., Plummer, L.N., Phillips, P.J., and Busenberg, 

E., 1994, Estimation and corroboration of shallow 

groundwater flow paths and travel times by environmental 

tracer and hydraulic analyses—A case study near Locust 

Grove, Maryland: Water Resources Research, v. 30, no. 2, 

p. 421–433.

Scott, J.H., Tibbetts, B.L., and Burdick, R.G., 1972, Computer 

analysis of seismic refraction data: U.S. Bureau of Mines 

Report of Investigation 7595, 95 p.

Sloto, R.A., and Crouse, M.Y., 1996, HYSEP—A computer 

program for streamflow hydrograph separation and analysis: 

U.S. Geological Survey Water-Resources Investigations 

Report 96–4040, 46 p.

Stute, M., and Schlosser, P., 1999, Atmospheric noble gases, 

in Cook, P., and Herczeg, A., eds., Environmental tracers 

in subsurface hydrology: Boston, Kluwer Academic 

Publishers, chap. 11, p. 349–377.

Stone, B.D., 1995, Progress toward higher resolution of the 

late Wisconsinan chronology of the New England region, 

30 to 13 ka: Geological Society of America, Abstracts with 

Programs, Northeastern Section, p. 84.

Tarr, R.S., 1905, Drainage patterns of central New York: 

Geological Society of America Bulletin, v. 16, p. 229–242.

Teller, J.T., 1987, Proglacial lakes and the southern margin of 

the Laurentide ice sheet, in Ruddiman, W.F., and Wright, 

H.E., Jr., North America and adjacent oceans during the 

last deglaciation: Boulder, Colorado, Geological Society of 

America, The Geology of North America, v. K–3, p. 39–69.

Thatcher, L.L., Janzer, V.J., and Edwards, K.W., 1977, 

Methods for determination of radioactive substances in 

water and fluvial sediments: U.S. Geological Survey 

Techniques of Water-Resources Investigations, book 5, 

chap. A5, p. 79–81.

U.S. Environmental Protection Agency, 2006, Drinking water 

standards and health advisories: U.S. Environmental 

Protection Agency, Office of Water, EPA 822–R–06–013, 

12 p.

U.S. Geological Survey, variously dated, National field manual 

for the collection of water-quality data: U.S. Geological 

Survey Techniques of Water-Resources Investigations, book 

9, chaps. A1-A9, available online at http://pubs.water.usgs.

gov/twri9A.

U.S. Geological Survey, 2004, CFC web page: accessed 

October 29, 2003, at http://water.usgs.gov/lab/cfc

 U.S. Geological Survey, 2009, New York annual water-data 

report 2006, in New York annual reports: U.S. Geological 

Survey web page accessed January 8, 2009, at http://

ny.water.usgs.gov/htmls/pub/data.html.
Appendix 1 51

Appendix 1

Records of selected wells in upper Sixmile Creek valley and part of West Branch Owego 

Creek valley, Town of Caroline, New York.
52 Geohydrology & Water Quality of the Valley-Fill Aquifer System in the Town of Caroline, Tompkins County, New York Appendix 1. Records of selected wells in upper Sixmile Creek valley and part of West Branch Owego Creek valley, Town of Caroline, New York.—Continued [ft, feet; in., inch; gal/min, gallons per minute; S&G, sand and gravel; >, greater than; USGS, U.S. Geological Survey; <, less than] Well site name Date drilled Well depth (ft) Depth of casing (ft) Casing diameter (in) Altitude land surface (ft) Aquifer type Water level below land surface (ft) Altitude water level (ft) Date water level measured Depth to bedrock (ft) Altitude top of bedrock (ft) Yield (gal/min) Remarks TM 53 8/1/1968 70 70 6 1,315 S&G (unconfined) 23.4 1,291.6 7/10/1980 50 0–68 silty gravel, silty >70 ft. TM 55 1972 83 83 6 1,280 S&G (confined) 25 1,255 1972 Clay over gravel. TM 56 90 90 6 1,189 S&G (unconfined?) Low yield. TM 57 10/1/1968 75 75 6 1275 S&G (confined?) TM 60 8/22/1966 101 29 5 935 Shale Flows 0 8/22/1966 29 906 30 0–29 sand and gravel, 29–101 ft shale. TM 61 10/10/1975 45 45 6 1,275 S&G (unconfined?)

5 1,270 10/10/1975

TM 62 10/10/1980 68 0 1,265 S&G 

(confined)

8.5 1,256.5 10/10/1980 Test boring. 0–12 clay, 12–68 sand and 

gravel.

TM 63 5/4/1905 38 38 5 1,282 S&G 

(confined)

10 1,272 1/1/1951 0–35 ft clay, sand and gravel 35–38 ft.

TM 69 1959 59 29 6 1,300 Shale 20 1,280 1959 29 1,271 6 Water at 20 ft in gravel.TM 71 1976 30 30 6 1,285 S&G 

(unconfined)

TM 73 1961 42 42 6 1,031 S&G 

(confined)

Large yield reported.

TM 74 1966 35 35 6 1,310 S&G 

(unconfined)

TM 75 1973 35 35 6 1,309 S&G 

(unconfined)

10 1,299 10

TM 76 1979 98 33 6 1,285 Shale 33 1,252 10TM 77 1967 32 32 1 1,285 S&G 

(unconfined)

0–6 gravel, 6–8 clay, 3–33 sand and 

gravel.

TM 78 1967 60 0 6 1,310 ShaleTM 80 1972 45 45 6 1,283 S&G 

(unconfined)

20 1,263 1972 Well in barn.
Appendix 1 53

Appendix 1. Records of selected wells in upper Sixmile Creek valley and part of West Branch Owego Creek valley, Town of Caroline, New York.—Continued[ft, feet; in., inch; gal/min, gallons per minute; S&G, sand and gravel; >, greater than; USGS, U.S. Geological Survey; <, less than]

Well 

site

name

Date 

drilled

Well 

depth 

(ft)

Depth 

of 

casing 

(ft)

Casing 

diameter

(in)

Altitude 

land 

surface 

(ft)

Aquifer 

type

Water 

level 

below 

land 

surface 

(ft)

Altitude 

water 

level 

(ft)

Date 

water 

level 

measured

Depth 

to 

bedrock 

(ft)

Altitude 

top 

of 

bedrock 

(ft)

Yield 

(gal/min) Remarks

TM 81 11/14/1966 20 20 6 1,052 S&G 

(unconfined?)

14 1,038 11/14/1966 7

TM 86 1965 206 28 6 1,130 Shale 40 1,090 11/1/1965 28 1,102 3 Bedrock at 28 ft.TM 982 32 30 2 1,063.0 S&G 

(confined)

Flows Driven well.

TM 983 6/18/1993 55 55 6 1,019.1 S&G 

(confined?)

13.0 1,006.09 6/16/2003 25 Well unused.

TM 984 6/26/1993 50 50 6 1,020.5 S&G 

(confined?)

12.14 1,008.36 6/16/2003 30 Well unused.

TM 986 86 86 5 1,109.0 S&G 

(confined)

Flows 0 7/20/2006 Town Hall well. Artesian flowing well.

TM 987 40 40 1,055.0 S&G 

(confined?)

Well in basement.

TM 988 100 14 5 1,040 Shale 100 34.7 10/11/2005 10 1,030 Well depth estimated.TM 989 46 46 5 1,150.0 S&G 

(confined?)

Well 5 ft below grade in pump house.

TM 990 56 56 5 1,049.9 S&G 

(confined?)

36.45 1,013.18 12/1/2004 Southernmost well. Casing 6 ft above 

land surface.

TM 994 12/28/2004 39 39 6 1,047.0 S&G 

(confined)

6.90 1,040.07 12/28/2004 160 887 20 USGS test well. Nested pair of wells 

(other well is TM1967).

TM 995 138 138 6 1,260 S&G 

(confined?)

Turbid- Cleared up after installing 

gravel pack.

TM 996 6/14/1988 45 45 6 1,285 S&G 

(unconfined)

24.2 1,262.6 8/23/2004 10

TM 999 8/7/1993 41 41 2 1,119.1 S&G 

(confined)

2.36 1,116.73 7/21/2006 Tompkins County Highway Dept. test 

well at Buffalo Road bridge.

TM1021 1901 101 101 6 1,101 S&G 

(confined)

Flows 1,115 1901 5 0–20 soil, 20-33 clay, 33–39 sand, 

39–47 clay, 47–53 S&G, 53–70 clay, 70–90 till, 90–110 sand.

TM1029 4/8/2005 69 69 5 1,015.0 S&G 

(confined)

48.15 966.62 4/12/2005 5 0–19 S&G, 19–27 silt/clay, 27–35 sand 

and gravel, 35–65 till, 65–69 ft sand and gravel.
54 Geohydrology & Water Quality of the Valley-Fill Aquifer System in the Town of Caroline, Tompkins County, New York Appendix 1. Records of selected wells in upper Sixmile Creek valley and part of West Branch Owego Creek valley, Town of Caroline, New York.—Continued [ft, feet; in., inch; gal/min, gallons per minute; S&G, sand and gravel; >, greater than; USGS, U.S. Geological Survey; <, less than] Well site name Date drilled Well depth (ft) Depth of casing (ft) Casing diameter (in) Altitude land surface (ft) Aquifer type Water level below land surface (ft) Altitude water level (ft) Date water level measured Depth to bedrock (ft) Altitude top of bedrock (ft) Yield (gal/min) Remarks TM1219 5/18/2000 48 48 6 1,190 S&G (unconfined) 10 1,180 5/18/2000 20 0–50 ft sand and gravel. TM1228 7/6/2000 100 21 5 1,255 Shale 20 1,235 7/6/2000 5 1,250 5 0–5 soil, 5–20 weathered shale, 20–100 shale. TM1252 8/18/2000 50 50 6 1,088.4 S&G (confined) Flows 1,091 8/18/2003 12 0–12 clay, 12–30 interlayered clay and gravel, 30–40 clay, 40–50 ft gravel. TM1261 8/15/2000 105 20 5 1,242 Shale 18 1,224 8/15/2000 15 1,227 5 0–15 till, 15–105 ft shale. DD= 60 ft at 5 gal/min. Specific capacity = 0.08 [(gal/min)/ft]. TM1369 8/7/2001 79 79 6 1,144 S&G (confined) 15 1,129 8/7/2001 20 0–10 clay, 10–20 clay w/ some gravel, 20–50 sandy clay, 50–78 clay, 78–79 ft gravel. TM1438 2/11/2002 117 101 5 1,410 Shale 31 1,323 2/11/2002 70 1,340 5 0–24 gravel, 24–70 till, 70–117 gray rock. TM1494 4/24/2002 29 29 6 1,273 S&G (confined) 17 1,256 4/24/2002 15 0–7 S&G, 7–19 S&G, 19–24 sand and clay, 24–28 clay, 28–29 gravel Specific capacity = 7.5 [(gal/min)/ft]. TM1504 6/4/2002 38 33 6 1,152 S&G (uncon- fined?)

8 1,144 6/4/2002 30 0–20 hardpan and stone, 20–38 ftsand 

and gravel.

TM1572 8/12/2002 30 30 6 1,259 S&G 

(unconfined)

5 1,254 8/12/2002 15 0–30 ft sand and gravel.

TM1613 10/9/2002 200 30 6 1,150 Shale 40 1,110 10/9/2002 25 1,125 8 0–20 clay, 20–22 gravel, 22–25 till, 

25–200 shale.

TM1624 10/15/2002 200 109 6 1,204 Shale 70 1,136 10/15/2002 108 1,096 3 0–29 till, 29–37 S&G, 37–70 till, 

70–103 till with sand and gravel layers, 103–108 till, 108–200 ft grey shale.

TM1643 2/3/2003 243 20 6 1,122 Shale 16 1,106 5 0–16 till, 16–243 shale.TM1645 1/8/2003 31 31 5 1,070 S&G 

(confined)

4 1,066 1/8/2003 20 0–26 clay and some gravel (till?), 

26–31 ft gravel.

TM1655 2/20/2003 135 20 6 1,190 Shale 35 1,155 2/20/2003 5 1,185 5 0–5 till, 5–135 ft shale.
Appendix 1 55

Appendix 1. Records of selected wells in upper Sixmile Creek valley and part of West Branch Owego Creek valley, Town of Caroline, New York.—Continued[ft, feet; in., inch; gal/min, gallons per minute; S&G, sand and gravel; >, greater than; USGS, U.S. Geological Survey; <, less than]

Well 

site

name

Date 

drilled

Well 

depth 

(ft)

Depth 

of 

casing 

(ft)

Casing 

diameter

(in)

Altitude 

land 

surface 

(ft)

Aquifer 

type

Water 

level 

below 

land 

surface 

(ft)

Altitude 

water 

level 

(ft)

Date 

water 

level 

measured

Depth 

to 

bedrock 

(ft)

Altitude 

top 

of 

bedrock 

(ft)

Yield 

(gal/min) Remarks

TM1708 6/19/2003 120 19 6 1,078 Shale 50 1,028 6/19/2003 12 1,066 8 0–12 till, 12–120 ft shale. Sulfur odor.TM1763 9/24/2003 40 40 6 1,135 S&G 

(unconfined)

5 1,130 9/24/2003 12 0–38 ft sand and gravel.

TM1802 12/4/2003 102 102 6 1,150 S&G 

(confined)

20 1,130 12/4/2003 15 0–10 gravel, 10–60 till and clay with 

sand layers, 60–98 clay with sand stringers, 98–102 ft sand and gravel.

TM1808 1/2/2004 61 61 6 1,137.4 S&G 

(confined)

1 1,136 1/2/2004 10 0–20 gravel, 20–30 till, 30–50 dirty 

gravel, 50–55 clay, 55–61 ft gravel.

TM1838 4/30/2004 42 42 6 1,034 S&G 

(confined)

20 1,014 4/30/2004 12 0–8 gravel, 8–40 clay, 40–42 ft sand 

and gravel.

TM1876 6/18/2004 76 76 6 1,134 S&G 

(confined)

10 1,124 6/18/2004 6 0–7 clay, 7–20 S&G, 20–44 sandy clay, 

46–48 sand and gravel (12 gal/min), 48–73 clay and sand, 73–76 ft sand and gravel.

TM1918 9/15/2004 220 21 6 1,195 Shale 80 1,115 9/16/2004 5 1,190 2 0–5 till, 5–220 ft shale.TM1925 10/5/2004 200 42 6 1,165 Shale 70 1,095 10/5/2004 80 1,085 3 0–20 gravel, 20–40 till, 80–200 ft shaleTM1967 12/28/2004 92 92 2 1,047.0 S&G 

(confined)

6.60 1,041.23 1/13/2005 160 887 20 USGS test well. 0–10 sand and gravel, 

10–30 silt/very fine sand, 30–43 sand and gravel, 43–63 fine sand, 63–77 clay, 77–160 ft sand and gravel (very sandy).

TM1968 8/11/2005 58 140 6 1,278.3 S&G 

(unconfined)

17.47 1,259.72 8/17/2005 20 Casing perf. 55–58 ft. 0–62 sand and 

gravel, 63–102 clay till, 102–110 m–c sand, 110–135 fine sand, 135–140 sand and gravel, 140–165 clay.

TM1970 1/31/2005 80 70 6 1,210 Shale 30 1,180 1/31/2005 70 1,140 10 0–60 till, 60–70 S&G, 70–80 ft shale.TM1979 3/16/2005 300 104 6 1,025.4 Shale 77.55 947.7 4/12/2005 104 921.4 1 <1 gal/min, 0–10 sand and gravel, 10–

27 clay and sand, 27–80 till, 80–104 sand and gravel, 104–300 ft shale.

TM1989 4/5/2005 53 53 6 1,158 S&G 

(confined)

5 1,153 4/2/2005 10 0–10 till, 10–34 sand and gravel, 34–48 

clay, 48–53 ft S&G.

TM2022 5/15/2005 121 19 6 1,105 Shale 17 1,088 7 0–17 till, 17–121 ft shale.
56 Geohydrology & Water Quality of the Valley-Fill Aquifer System in the Town of Caroline, Tompkins County, New York Appendix 1. Records of selected wells in upper Sixmile Creek valley and part of West Branch Owego Creek valley, Town of Caroline, New York.—Continued [ft, feet; in., inch; gal/min, gallons per minute; S&G, sand and gravel; >, greater than; USGS, U.S. Geological Survey; <, less than] Well site name Date drilled Well depth (ft) Depth of casing (ft) Casing diameter (in) Altitude land surface (ft) Aquifer type Water level below land surface (ft) Altitude water level (ft) Date water level measured Depth to bedrock (ft) Altitude top of bedrock (ft) Yield (gal/min) Remarks TM2023 5/24/2005 114 114 6 1,267.4 S&G (confined) 48.50 1,220.69 8/17/2005 30 Pumps sand,. 0–29 S&G, 29–40 sand, 40–80 fine sand, 80–108 clay, 108–114 ft S&G. TM2028 7/1/2006 200 166 6 1,110 Shale Flows 1115 7/1/2006 165 945 15 0–14 gravel, 14–17 clay, 17–24 S&G, 24–40 clay, 40–49 sand, 49–65 ?, 65–77 gravel, 77–165 till, 165–200 shale. TM2071 8/23/2005 200 23 6 1,185 Shale 10 1,175 2 0–10 till, 10–200 ft shale. TM2079 9/7/2006 173 65 6 1,360 Shale 63 1,297 15 0–63 till, 63–173 ft shale. TM2101 9/28/2006 180 20 6 1,100 Shale 60 1,040 9/28/2005 16 1,084 10 0–16 till, 16–180 ft shale. TM2129 11/2/2005 28 28 6 1,274 S&G (unconfined) 10 1,264 11/2/2005 15 0–28 ft gravel. TM2154 2/25/2005 100 0 0 1,165 Shale 40 1,125 2/25/2005 6 TM2166 1/12/2006 57 57 6 1,085 S&G (confined) 20 1,065 1/12/2006 12 0–7 gravel, 7–38 clay, 38–40 gravel, 40–55 clay, 55–57 ft gravel. TM2176 2/27/2006 52 52 5 1,060 S&G (confined) Flows 2/27/2006 20 Flowing. 0–17 till, 17–35 clay, 35–52 sand, 52–60 gravely sand, 60–61 ft clay. TM2233 6/19/2006 180 60 6 1,365 Shale 70 1,295 6/19/2006 55 1,310 15 0–20 till, 20–28 gravel, 28–55 till, 55–180 ft shale. TM2302 11/1/2006 29 29 6 1,300 S&G (unconfined)

8 1,292 11/1/2006 12 0–27 gravel, 27–45 ft clay.

TM2344 2/12/2007 171 93 6 1,000 Shale 63 937 2/12/2007 90 910 20 0–10 sand and gravel, 10–90 till, 

90–171 ft shale.
Prepared by the Pembroke Publishing Service Center

and the West Trenton Publishing Service Center 

For additional information write to:

New York Water Science Center

U.S. Geological Survey

425 Jordan Road

Troy, NY 12180

Information requests:

(518) 285-5602

or visit our Web site at:

http://ny.water.usgs.gov
Miller—Geohydrology and Water Quality of Aquifers in Upper Sixmile Creek and West Branch Qswego Creek Valleys, New York —Scientific Investigations Report 2009–5173

Printed on recycled paper