Hydraulic, Geochemical, and Thermal Monitoring of an Aquifer System in the Vicinity of Mammoth Lakes, Mono County, California, 2015–17

Open-File Report 2019-1063
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  • Document: Report (8 MB pdf)
  • Data Release: Data Release - Atmospheric-loading frequency response functions and groundwater-levels filtered for the effects of atmospheric loading and solid Earth tides for three monitoring wells near Mammoth Lakes, California, 2015–2017
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Since 2014, the U.S. Geological Survey has been working in cooperation with the Bureau of Land Management, Mono County, Ormat Technologies, Inc., and the Mammoth Community Water District to design and implement a groundwater-monitoring program for the proposed Casa Diablo IV Geothermal Power Project in Long Valley Caldera, California, to characterize baseline groundwater-level, water-temperature, and water-chemistry conditions at dedicated monitoring wells and municipal supply wells. The publicly available data and the analyses provided here represent quality-assured and peer-reviewed information to help with the management of the thermal and non-thermal water resources beneath and in the vicinity of the town of Mammoth Lakes, California.

The methods of data collection for continuous water levels and quarterly water-temperature profiles for two 600-foot-deep monitoring wells during 2016 through 2017 are discussed. Also discussed are the methods of water-sample collection and characterizations of the water chemistry in numerous wells in the multilayered aquifer system beneath Mammoth Lakes. Additionally, the methodology used to develop digital (mathematical) filters to remove or reduce the effects of barometric pressure and solid Earth tides on the continuous water-level records is discussed.

Digitally filtered water levels for a 2017 flow test of a deep geothermal production well are described, and various aquifer responses observed during the flow test are discussed. These are further considered in a companion evaluation of potential physical and chemical influences on the water-level data collected during the flow test.

The digitally filtered water-level data indicated that some hydraulic communication exists between the deep geothermal aquifer and shallow groundwater aquifer at the location of the flow test, northeast of Mammoth Lakes. Groundwater-chemistry data from three wells indicated that shallow groundwater naturally mixes with a small component of geothermal water along the northern periphery of the shallow aquifer system at Mammoth Lakes.

Suggested Citation

Howle, J.F., Evans, W.C., Galloway, D.L., Hsieh, P.A., Hurwitz, S., Smith, G.A., and Nawikas, J., 2019, Hydraulic, geochemical, and thermal monitoring of an aquifer system in the vicinity of Mammoth Lakes, Mono County, California, 2015–17: U.S. Geological Survey Open-File Report 2019–1063, 90 p., https://doi.org/10.3133/ofr20191063.

ISSN: 2331-1258 (online)

Study Area

Table of Contents

  • Acknowledgments
  • Abstract
  • Introduction
  • Monitoring-Well Network
  • Methods
  • Groundwater-Level Data
  • Water-Temperature Profiles
  • Water-Chemistry Comparisons
  • Water-Level Variations During a Flow Test of a Geothermal Production Well
  • Potential Physical and Chemical Influences on Water-Level Data
  • Summary
  • References Cited
  • Appendixes
Publication type Report
Publication Subtype USGS Numbered Series
Title Hydraulic, geochemical, and thermal monitoring of an aquifer system in the vicinity of Mammoth Lakes, Mono County, California, 2015–17
Series title Open-File Report
Series number 2019-1063
DOI 10.3133/ofr20191063
Year Published 2019
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) California Water Science Center
Description Report: xii, 90 p.; Data release
Country United States
State California
County Mono County
Online Only (Y/N) Y
Google Analytic Metrics Metrics page
Additional publication details