Geohydrology and Water Quality of the Unconsolidated Aquifers in the Enfield Creek Valley, Town of Enfield, Tompkins County, New York

Scientific Investigations Report 2019-5136
Prepared in cooperation with the Town of Enfield and the Tompkins County Planning Department
By: , and 

Links

  • Document: Report (14.4 MB pdf)
  • Data Releases:
    • USGS data release - Horizontal-to-vertical spectral ratio soundings and depth-to-bedrock data for geohydrology and water quality investigation of the unconsolidated aquifers in the Enfield Creek Valley, town of Enfield, Tompkins County, New York, April 2013–August 2015
    • USGS data release - Records of selected wells for geohydrology and water quality investigation of the unconsolidated aquifers in the Enfield Creek Valley, town of Enfield, Tompkins County, New York, 2013–2018
  • Open Access Version: Publisher Index Page
  • Download citation as: RIS | Dublin Core

Abstract

From 2013 to 2018, the U.S. Geological Survey, in cooperation with the Town of Enfield and the Tompkins County Planning Department, studied the unconsolidated aquifer in the Enfield Creek Valley in the town of Enfield, Tompkins County, New York. The valley will likely undergo future development as the population of Tompkins County increases and spreads out from the metropolitan areas. The Town of Enfield, Tompkins County, and the New York State Departments of Health and Environmental Conservation need geohydrologic information to help planners develop a more comprehensive approach to water-resource management in Tompkins County.

The Enfield Creek Valley is underlain by an unconfined aquifer that consists of saturated alluvium, alluvial-fan deposits, and ice-contact (kame) sand and gravel. A confined aquifer of discontinuous ice-contact sand and gravel overlies bedrock. Depth to bedrock in the valley ranges from about 50 feet below land surface from just north of the Enfield Creek divide in the northern part of the aquifer to the confluence of Fivemile Creek to at least 140 feet below land surface from Fivemile Creek to where the valley orientation changes from north-south to northwest-southeast. Depth to bedrock is much shallower from the valley orientation change to the southeastern part of the aquifer because Enfield Creek has carved through overlying sediments into bedrock as the creek drops 450 feet into the Cayuga Inlet Valley. A small buried valley running south to north was identified within the Fivemile Creek drainage along the western edge of the town. However, the valley fill consists of glacial till, and no sand-and-gravel aquifer is present.

The unconfined aquifers are recharged by direct infiltration of precipitation, surface runoff, and shallow subsurface flow from hillsides, and by seepage loss from streams overlying the aquifer. The confined aquifers are recharged mostly by precipitation that enters the adjacent valley walls, by groundwater flowing from bordering till or bedrock, and by flow from the bottom of the valley. Also, some recharge may be occurring where confining units are absent or from confining units with sediments of moderate permeability.

Groundwater discharges to Enfield Creek, its tributaries, and wetlands and is lost through evapotranspiration from the water table or is withdrawn from domestic, commercial, and agricultural wells. About 700 individual well owners depend on the unconsolidated aquifers for their water supply. An estimated 28,300,000 gallons per year are withdrawn.

Groundwater samples were collected from eight test wells drilled for this study, and six surface-water samples were collected from five locations on Enfield Creek. Of the eight wells sampled, two were finished in unconfined sand-and-gravel aquifers, two were finished in confined sand-and-gravel aquifers, and four were finished at or near the shale bedrock surface.

Water quality in the study area generally met State and Federal drinking-water standards. However, some samples exceeded maximum contaminant levels for barium (25 percent of samples) and secondary maximum containment levels for chloride (25 percent), dissolved solids (25 percent of samples), iron (70 percent of samples), and manganese (75 percent of samples). Groundwater from 75 percent of the wells sampled for methane had concentrations greater than the Office of Surface Mining Reclamation and Enforcement recommended action level of 10 to 28 milligrams per liter. The two deepest wells sampled, TM1075 and TM1077, had the highest specific conductance, chloride, and sodium concentrations of all wells sampled. The chloride/bromide ratios of these samples suggest the source may represent a mixture of saline formation waters with shallow dilute groundwater and may receive recharge contribution from two tributaries overlying bedrock to the west and southwest of the aquifer. In general, the highest yields are from wells completed within about 50 feet below land surface, which may tap either type of aquifer.

Suggested Citation

Fisher, B.N., Heisig, P.M., and Kappel, W.M., 2019, Geohydrology and water quality of the unconsolidated aquifers in the Enfield Creek Valley, town of Enfield, Tompkins County, New York: U.S. Geological Survey Scientific Investigations Report 2019–5136, 52 p., https://doi.org/10.3133/sir20195136.

ISSN: 2328-0328 (online)

Study Area

Table of Contents

  • Abstract
  • Introduction
  • Methods of Investigation
  • Depositional History and Framework of Glacial and Postglacial Deposits
  • Groundwater Recharge, Discharge, and Withdrawals
  • Water Quality of the Unconsolidated Aquifers in the Enfield Creek Valley
  • Summary
  • References Cited
  • Appendix 1. Well Logs of Test Wells Drilled in the Enfield Creek Unconsolidated Aquifer, Town of Enfield, Tompkins County, New York
  • Appendix 2. Test-Well Hydrographs in the Enfield Creek Unconsolidated Aquifer, Town of Enfield, Tompkins County, New York
  • Appendix 3. Air and Water Temperatures by Depth at Test Wells TM1075 and TM 1077 in the Enfield Creek Unconsolidated Aquifer, Town of Enfield, Tompkins County, New York

Additional publication details

Publication type Report
Publication Subtype USGS Numbered Series
Title Geohydrology and water quality of the unconsolidated aquifers in the Enfield Creek Valley, town of Enfield, Tompkins County, New York
Series title Scientific Investigations Report
Series number 2019-5136
DOI 10.3133/sir20195136
Year Published 2019
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) New York Water Science Center
Description Report: vi, 52 p.; 2 Data Releases
Country United States
State New Rork
County Tompkins County
Other Geospatial Enfield Creek Valley, Town of Enfield
Online Only (Y/N) Y
Additional Online Files (Y/N) Y