Background and Problem
Tully Valley is part of the Onondaga Trough, which extends from the Valley Heads Moraine in the south to Onondaga Lake in the north near Syracuse, New York (fig. 1). The Onondaga Trough is filled with a complex sequence of glacial and post-glacial sediments that overlie Devonian carbonate rock and shale and Silurian shale and salt (fig.2). Mudboils, volcano-like cones of fine sand and silt, have been documented in the Tully Valley since the late 1890s, and have been continuously discharging turbid water into Onondaga Creek since the 1950s (Kappel and others, 1996). Continuous mudboil activity appears to be correlated with salt solution-mining activities in brine fields at the southern end of the Tully Valley, which began in 1889 and ended in 1986 (Kappel and others, 1996; Yanosky and Kappel, 1997). Groundwater discharged by the mudboils was initially fresh, but has become increasingly saline since the 1970s (Kappel, 2014). Remedial measures proposed by the Mudboils Technical Advisory Group (MBTAG) and others to reduce the artesian pressure and recharge that drives mudboil activity include groundwater withdrawals from bedrock and (or) glacial aquifer zones and lining of tributary streambeds up-gradient of the mudboils.
Objectives
The objective of the study is to provide information on the hydrogeological framework and sources of water to the Tully Valley mudboils through surface-geophysical and groundwater-geochemical data collection and integrated analysis with existing geological, hydrological, and geochemical data.
Approach
The study approach will include: 1) compilation and GIS mapping of available geological, hydrological, and geochemical data previously collected from well, mudboil, spring, and surface-water sites (fig. 1); 2) non-invasive surface-geophysical soundings; 3) additional groundwater sampling from selected sites for analysis of major ions, trace metals, and environmental tracers; and 4) integrated analysis of the new geophysical and groundwater-geochemical results with existing hydrogeological and geochemical data to develop a conceptual hydrogeological model of Tully Valley.
Surface-Geophysical Soundings
The surface-geophysical methods to be applied in the proposed study are time-domain electromagnetics and passive seismic. The geophysical data sets will be analyzed as an integrated suite with available well logs and chloride and specific conductance data to maximize their synergistic nature. State-of-the-art software will be used to develop two-dimensional representations of the Tully Valley that present the subsurface electrical resistivity/conductivity of the valley fill and bedrock, thickness of the valley fill and depth to bedrock, and distribution of brine and saline water. Knowledge of the hydrogeological framework and fresh-saline distribution gained from the analysis of the surface-geophysical data will further our understanding of the groundwater-flow system in the valley, and provide constraints for the potential future development of a numerical model to better understand artesian pressures in the aquifers, flowpaths to the mudboils, and recharge sources.
Time-Domain Electromagnetic Because saline water is much more electrically conductive than fresh water, electrical and electromagnetic geophysical methods can be used to delineate the distribution of saline and fresh water in the subsurface. Time-domain electromagnetics (TDEM), a rapid surface-geophysical sounding method, will be used to measure the electrical resistivity/conductivity of the shallow to deep subsurface (fig. 3). Fitterman and Hoekstra (1984) applied the TDEM sounding technique to the mapping of naturally occurring brine contamination in central Michigan. Stewart and Gay (1986) and Fitterman and Prinos (2011) used TDEM soundings to map saltwater intrusion in south Florida. Williams and others (2017) are applying the TDEM method in their investigation of brine migration from the collapsed Retsof salt mine in the Genesee River, Livingston County, New York. In this ongoing investigation, analysis of TDEM soundings along a cross-valley transect at the mine-collapse area delineated the brine-filled bedrock-rubble chimney and migration of saline water into the glacial valley-fill aquifer (fig. 4).
For the proposed study, TDEM soundings will be completed at about 70 sites along ten or more transects across the Tully Valley (fig. 5). 40-meter transmitter loops will be used depending on their effective investigation depths and the available land area. The specific locations of the soundings will be limited by landowner permission, distribution of cultural features (overhead and buried utilities), and the terrain (water bodies and swampy areas). A prototype towable TDEM system, which produces resistivity/conductivity soundings every several feet, was recently tested in the Tully Valley with about 4 miles of nearly continuous TDEM data being collected (fig. 5).
Horizontal-to-Vertical Seismic Depth to bedrock, an important hydrogeological framework component, is unknown at many locations in the Tully valley. Horizontal-to-vertical spectral ratio (HVSR) seismic, which is an ambient-noise passive surface-geophysical technique, will be used to estimate the thickness of the valley fill and depth to bedrock (Lane and others, 2008). HVSR seismic measurements will be completed at each of the TDEM sounding locations. The depth-to-bedrock information will provide an important parameter constraint for the interpretation of the TDEM data. The analyzed passive seismic data will be compared to existing/known depth to bedrock locations at multiple points to develop a regression that relates seismic resonance frequency to depth to bedrock; data from HVSR locations without known depth to bedrock will be calculated based on that regression and an estimate of error of depth to bedrock will be established.
Groundwater-Geochemical Sampling
Groundwater-geochemical samples will be collected from about 15 mudboil, spring, and well sites. The mudboil, spring, and well sites will be selected for sampling based on a review of groundwater chemistry analyses from mudboil research conducted during 1992 to 2012 (Kappel, 2014), and a valley-wide specific-conductance survey of mudboil and spring discharges conducted as part of the current project. The groundwater samples will be analyzed for major ions and trace metals to determine geochemical water types. A subset of samples will be analyzed for selected environmental tracers to evaluate groundwater age and mixing. Environmental tracers used for groundwater age dating and mixing models include chlorofluorocarbons (CFCs), sulfur hexafluoride (SF6), tritium (3H), and tritium/helium-3 (3H/3He), and carbon isotopes (14C and δ13C) (Nelms and others, 2003). Knowledge of groundwater types, ages, and mixing will further our understanding of the groundwater-flow system in the valley, and will provide constraints for the potential future development of a numerical model to better understand recharge sources, flowpaths, and travel times to the mudboils.
Groundwater samples will be collected and preserved following U.S. Geological Survey (2006) established protocols. Samples will be collected and preserved in a sampling chamber according to standard USGS procedures (U.S. Geological Survey, 2006). Samples for major-ion and some trace-element analyses will be filtered through disposable (one-time use) 0.45-micrometer pore-size polyether sulfone capsule filters that were preconditioned in the laboratory with 3 liters of deionized water the day before sample collection and stored on ice until use in the field. Ten percent of the groundwater-chemistry samples will be replicates (5 percent) and field blanks (5 percent) for QA/QC purposes. The groundwater-chemistry data will be managed following policies presented in the “Quality-Assurance Plan for Water-Quality Activities in the New York Water Science Center”. Major cations and anions and trace elements (table 1) will be analyzed by the USGS National Water-Quality Laboratory in Denver, Colorado. The environmental tracers will be analyzed by the USGS Groundwater Dating Laboratory in Reston, Virginia.
References
Fitterman, D.V., and Hoekstra, P., 1984, Mapping of saltwater intrusion with transient electromagnetic soundings, in Proceeding of the NWWA/EPA Conference on Surface and Borehole Geophysical Methods in Ground Water Investigations, February 7-9, 1984, San Antonio, Texas, p. 429-454.
Fitterman, D. V. and Prinos, S. T., 2011, Results of time-domain electromagnetic soundings in Miami-Dade and southern Broward Counties, Florida, U.S. Geological Society Open-File Report 2011-1299, 42 p., https://pubs.usgs.gov/of/2011/1299/ .
Johnson, C.D., White, E.A., Williams, J.H., and Kappel, W.M., 2017, Transient electromagnetic surveys collected for delineation of saline groundwater in the Genesee Valley, New York, October-November 2016: U.S. Geological Survey data release https://doi.org/10.5066/F79C6VXX .
Kappel, W.M., 2009, Remediation of mudboil discharges in the Tully Valley of central New York: U.S. Geological Survey Open-File Report 2009-1173, 8 p., https://pubs.usgs.gov/of/2009/1173/ .
Kappel, W.M., 2014, The hydrogeology of the Tully Valley, Onondaga County, New York—An overview of research, 1992–2012: U.S. Geological Survey Open-File Report 2014–1076, 28 p., plus 3 appendixes https://dx.doi.org/10.3133/ofr20141076 .
Kappel, W.M., Sherwood, D.A., and Johnston, W.H., 1996, Hydrogeology of the Tully Valley and characterization of mudboil activity, Onondaga County, New York: U.S. Geological Survey Water-Resources Investigations Report 96-4043, 71 p., https://ny.water.usgs.gov/pubs/wri/wri964043 .
Lane, J.W., Jr., White, E.A., Steele, G.V., and Cannia, J.C., 2008, Estimation of bedrock depth using the horizontal-to-vertical (H/V) ambient-noise seismic method, in Symposium on the Application of Geophysics to Engineering and Environmental Problems, April 6-10, 2008, Philadelphia, Pennsylvania, Proceedings: Denver, Colorado, Environmental and Engineering Geophysical Society, 13 p.
Langevin, C.D., Thorne, D.T., Jr., Dausman, A.M., Sukop, M.C., and Guo, Weixing, 2007, SEAWAT Version 4: A Computer Program for Simulation of Multi-Species Solute and Heat Transport: U.S. Geological Survey Techniques and Methods Book 6, Chapter A22, 39 p., available online at https://pubs.usgs.gov/tm/tm6a22/ .
Nelms, D.L., Harlow, G.E., Jr., Plummer, L. N., and Busenberg, Eurybiades, 2003, Aquifer susceptibility in Virginia, 1998-2000: U. S. Geological Survey Water-Resources Investigations Report 03-4278, 58 p. http://pubs.er.usgs.gov/publication/wri034278
Stewart, M. and Gay, M., 1986, Evaluation of transient electromagnetic soundings for deep detection of conductive fluids, Ground Water, 24, p. 351–356.
U.S. Geological Survey, variously dated, National field manual for the collection of water-quality data: U.S. Geological Survey Techniques of Water-Resource Investigations, book 9, chaps. A1–A9 [variously paged], available online at http://pubs.water.usgs.gov/twri9A .
U.S. Geological Survey, 2006, Collection of water samples (ver. 2.0): U.S. Geological Survey Techniques of Water-Resources Investigations, book 9, chap. A4, September 2006, available online at http://pubs.water.usgs.gov/twri9A4/.
Williams, J.H., Kappel, W.M., Johnson, C.D., White, E.A., and Heisig, P.M., 2017, Time-domain electromagnetic soundings for the delineation of saline groundwater in the Genesee River valley, western New York: New York State Geological Association, Guidebook for Field Trips in New York, 2017 Annual Meeting, v. 89, available online at file:///C:/Users/jhwillia/Downloads/TDEM%20NYSGA.pdf
Yager, R.M., Kappel, W.M., and Plummer, L.N., 2007, Halite brine in the Onondaga Trough near Syracuse, New York: Characterization and simulation of variable-density flow, U. S. Geological Survey Scientific Investigations Report 2007-5058, 40 p., available online at https://pubs.usgs.gov/sir/2007/5058/ .
Yanosky, T.M., and Kappel, W.M., 1997, Tree ring record 100 years of hydrologic change within a wetland: U.S. Geological Survey Fact Sheet FS 057-97, 4 p., https://ny.water.usgs.gov/pubs/fs/fs05797/ .
Project
Location by County
Onondaga County, NY
