Paper No. 10
Presentation Time: 10:40 AM

THE WATER QUALITY CHALLENGE: USING NEW TECHNOLOGY TO TRACK TECTONIC SALINITY CONTRIBUTIONS THAT IMPAIR SURFACE AND GROUNDWATER


CROSSEY, Laura J.1, SHERSON, Lauren2, KARLSTROM, Karl E.2, MCGIBBON, Chris2, JOCHEMS, Andrew P.3, ALI, Abdul-Mehdi S.2, PERSON, Mark4, DAHM, Clifford N.5 and PARMENTER, Robert R.6, (1)Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, NM 87131-0001, (2)Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, NM 87131, (3)Geology, Utah State University, 4505 Old Main Hill, Logan, UT 84322, (4)Dept of Earth & Environmental Science, New Mexico Tech, 801 Leroy Place, Socorro, NM 87801, (5)Biology, University of New Mexico, MSC03 2020, 1 University of New Mexico, Albuquerque, NM 87131-0001, (6)Valles Caldera Trust, P.O. Box 359, 18161 State Highway 4, Jemez Springs, NM 87025, lcrossey@unm.edu

In the southwestern US, saline surface water and brackish groundwater pose particular problems in water management. The contribution of deep groundwaters (including geothermal systems) to streams and shallow unconfined aquifers is often underappreciated. Quantitative forecasting of the effects of climate change (diminishing surface flows) on water quality depends on our understanding of these deep inputs. The Jemez and Rio Salado watersheds in northern New Mexico are classic examples of arid-region salinization due in part to tectonic inputs (deep fluids emerging along fault conduits). Additionally, these watersheds have been impacted by major fire disturbance and associated water quality impairments. These hydrologic systems are important both to local constituencies (including a mix of private, tribal and public lands) as well as regional managers because of their contribution to the middle Rio Grande system, and as recharge components to Sandoval County and the northwestern part of the Albuquerque groundwater basin.

Two integrated datasets are presented to demonstrate how a quantitative loading model for particular solutes of concern (in this case, sulfate and arsenic) can be integrated with climate change scenarios. (1) Traditional ‘campaign’ water sampling over the 2006-2013 water years along a 60 km reach of the Jemez shows that during low flow the salinity, sulfate concentration, and arsenic concentration all exceed designated use limits. Trace elements and carbon isotopes demonstrate the extent of geothermal inflows. Stable isotopes of water (D, O) can be used for hydrograph separation. (2) The deployment of continuous sensors for temperature, salinity, pH, and dissolved oxygen in the Jemez in 2010-2013 provides information on coupling of discharge, temperature, dissolved oxygen, pH and specific conductance at a highly resolved timescale. Combined, these results indicate the need for a wider application of environmental sensors in hydrologic systems to inform water management decisions. Climate change scenarios predicting reduced snowpack and changes in runoff timing, linked to a solute loading/discharge model and our hydrochemical data, highlight serious water quality concerns for the Jemez river and the downstream stakeholders.