This slide show presentation was utilized at the Nov. 16, 2023 event "Think Science: Geoscience & Groundwater" and features contributions from: Dr. Ben Surpless, Trinity University Dr. Saugata Datta, UTSA Dr. Brady Ziegler, Trinity University

1. DR. BEN SURPLESS
DR. BRADY ZIEGLER
DR. SAUGATA DATTA
the intersection of geoscience and
groundwater
Think Science

2. FAULTING,
Think Science
RESEARCH APPLICATIONS:
Geothermal energy potential
Groundwater pathways
the intersection of geoscience and groundwater
Dr. Ben Surpless, Professor and Chair
FRACTURING,
AND FLUID FLOW
K2 in the Himalayas (Getty Images)

3. AS FAULTS LENGTHEN AND CUT THROUGH ROCK IN THE CRUST…
…THEY DAMAGE (FRACTURE) THE ROCK AROUND THEM.
FRACTURES INCREASE PERMEABILITY AND
INCREASE GROUNDWATER FLOW
CONCEPTUAL BACKGROUND
WHY DO FAULTS FORM?
FORCES WITHIN THE EARTH’S CRUST CAUSE INTACT ROCK TO FRACTURE
THIS LEADS TO THE FORMATION AND GROWTH OF FAULTS

4. BUT HOW DO WE KNOW THAT THESE PROCESSES OCCUR WITHIN THE EARTH?
Field data collection is the key
to understanding subsurface
fracture networks!

5. GEOTHERMAL ENERGY POTENTIAL
Many of the best field sites would require
extraordinarily dangerous field-data collection!

6. From our own depth perception (our eyes)
to computer-generated depth perception
and point matching
GEOTHERMAL ENERGY POTENTIAL

7. Image point-matching to build a
computer-generated 3D landscape
GEOTHERMAL ENERGY POTENTIAL

8. We can use this type of modeling to help
scientists predict fluid flow within fault-
related geothermal systems across the
western US
GROUNDWATER FLOW
GEOTHERMAL ENERGY POTENTIAL

9. San Antonio
The Hill Country
Contributing
zone Recharge
zone
Artesian
zone
The Balcones
fault zone
Impermeable
rock formation
Edwards
Group
(porous and
permeable)
Impermeable
Porous and
permeable
Impermeable
GROUNDWATER FLOW

10. Where an aquifer is recharged depends on the type of aquifer.
This has implications for groundwater contamination.
Recharge zone for
confined aquifer
Recharge zone for
unconfined aquifer

11. However, groundwater contaminants don’t only
originate at the surface.
From USGS Circular 1346

12. fertilizers, pesticides, herbicides
personal care
products
pharmaceuticals
chemical spills
landfill leachate
bacteria,
viruses
PFAS “forever
chemicals”
mercury
(cinnabar)
uranium
(uraninite)
cadmium
(greenockite)
arsenic
(realgar)
lead (galena)
chlorine
(halite)
Iron oxide
+
+
+
+
+
Petroleum
hydrocarbons
dissolved
iron, arsenic
uraninite
nitrate
fertilizers
dissolved
uranium

13. Chemical spills are incredibly common.
Data from Pipeline and Hazardous Materials Safety Administration

14. At least one contaminant
above safe level
At least one contaminant
above half of safe level
All contaminants below
half of safe levels
Explanation
Groundwater quality is a nationwide challenge.
Report from the USGS National
Water Quality Assessment

15. QR code for the EPA
primary drinking water
standards website
About 90 chemicals are regulated at the federal level based
on toxicity studies to protect public health.
69 additional chemicals on
the EPA Contaminant
Candidate List

16. There are nine major aquifer systems in Texas.
Texas Water Development
Board Report

17. Arsenic contamination in Texas is geologically
restricted to the Ogallala and Gulf Coast Aquifers.
Texas Water Development Board
Report: “Naturally Occurring
Groundwater Contamination in Texas”

18. Texas Water Development Board
Report: “Naturally Occurring
Groundwater Contamination in Texas”
Uranium contamination data are more sparse.

19. Elevated uranium corresponds to elevated nitrate
from agricultural fertilizers.
Texas Water Development Board
Report: “Naturally Occurring
Groundwater Contamination in Texas”

20. Factors to consider for potential groundwater contamination.
Unconfined aquifers Confined aquifers
Human-sourced contaminants
Are chemicals being applied to the
surface environment, either
purposefully or accidentally?
Are chemicals being applied to the
surface environment, either
purposefully or accidentally?
Does the application occur over the
recharge zone?
Geologic contaminants
What minerals make up the aquifer?
How do those minerals react with
natural groundwater chemistry?
Are humans modifying water
chemistry that can trigger a reaction
with aquifer minerals?
What minerals make up the aquifer?
How do those minerals react with
natural groundwater chemistry?
Are humans modifying water
chemistry that can trigger a reaction
with aquifer minerals?

21. To check the status of your drinking water quality:
Using a private well?
The homeowner is responsible for
water quality testing
SAWS 2023 Water
Quality Report
Environmental Working
Group Report for SAWS
EWG Assessment: “tap
water provided by this water
utility was in compliance
with federal health-based
drinking water standards”
Using municipal water?
The municipality is responsible to be compliant
with drinking water regulations
Water Development Board Guidelines
for Sampling Private Wells

22. Geoscience and
Groundwater
Dr. Saugata Datta
 Professor and Chair, Department of Earth
and Planetary Sciences, The University of
Texas at San Antonio
 Director, Institute of Water Research,
Sustainability and Policy at UTSA.
16 Nov, 2023

23.  Number of health-based violations, 1982–2015, by contaminant
type (graph to left)
 Number of total violations per CWS (map above), 1982–2015, by
county. Note high number of violations in Texas state
 Statistical method used to represent spatial clusters (hot spots) of
health-based violations of SDWA during 1982-2015 (map to left).
Again, note the hot-spots in the state of Texas.
Allaire, M., Wu, H. and Lall, U., 2018. National trends in drinking water quality violations.
Proceedings of the National Academy of Sciences, 115(9), pp.2078-2083.
https://doi.org/10.1073/pnas.1719805115

24. Lead Contamination
in Flint (MI)
Pieper, K.J., Martin, R., Tang, M., Walters, L., Parks, J., Roy, S., Devine, C. and Edwards, M.A.,
2018. Evaluating water lead levels during the Flint water crisis. Environmental science &
technology, 52(15), pp.8124-8132. https://doi.org/10.1021/acs.est.8b00791
 An example of how water chemistry can directly impact
human health
 Switching water sources (more corrosive) in old pipes
without corrosion control led to mobilization of Lead

25. One of our studies – source apportionment of Lead in children’s blood using
Pb-isotopes geochemistry
 Old houses likely have high
concentrations of lead in
paints
 Exposure through dust, soil,
paint and household objects

26. Source: U.S. Government Accountability Office
Potential Lead in Pipe Infrastructure
https://www.nrdc.org/resources/lead-pipes-are-widespread-and-
used-every-state
Prior incidences like Flint, MI signify the necessity of
monitoring our drinking water supplies more carefully

27. Currently GOOD EA Groundwater Quality But recent studies show presence of contaminants –
pesticides, herbicides and VOCs
Highly conductive and productive aquifer like Edwards Aquifer is prone
to contamination if surface conditions change such as land usage
Lead monitoring
programs are already
in place – Harris
County, Texas

28. UTSA – EAA Project to investigate impacts of land usage on
EA groundwater quality

29. Selected trace element concentrations
in the groundwater samples of the
representative colonias’ collected
over 4 counties in the US-Mexico
border (Primary Investigation).
Selected major ion and trace element concentrations in the groundwaters monitored by
USGS over 10 representative counties in the US-Mexico border
Background Groundwater
Quality database of the US-
Mexico borderline counties
Study area and Strategic Sampling
Preliminary observations

30. Historical Groundwater
Quality Data from EA
Note the gradually increasing
concentrations of certain contaminants
(As, Cu) in EA groundwater – ongoing
investigations

31. Unmonitored Private Well Water Supply in Nine Counties along US – Mexico
Border in Texas

32. 32
How does arsenic mobilize?

33. Since 2020
UTSA’s Role in Water Science

34. Water
Pollution
Prevention
 Education and Research
 Policy and Regulations
 Implementation and
enforcement
 Citizens Science and Social
Responsibility

35. Thank you !
Questions?