This is the PowerPoint prepared by Dr. Saugata Datta (UTSA) for Texas Public Radio's Think Earth event held on October 7, 2022. The slide presentation focuses on water pollution, and matches with the audio on this page: https://www.tpr.org/tpr-events-initiatives/2022-09-28/think-earth-pollution

1. Water Pollution
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.
Friday 7th October 2022

2. Water Pollution Remains Top Environmental Concern in US!
https://news.gallup.com/poll/347735/water-pollution-remains-
top-environmental-concern.aspx
Survey of 1,010 adults from
50 states and DC

3. Safe Drinking Water Act (SDWA)
 Passed by Congress in 1974
 To protect public health by regulating nation’s public water drinking water supply
 Drinking water and its sources include rivers, lakes, reservoirs, springs, and ground water wells.
 Does not regulate private wells which serve less than 25 individuals
Primary Drinking Water Standards - Microbial

4. Primary Drinking Water Standards - Inorganic Chemicals

5. Other Primary Regulated Contaminants
 Disinfectants (n = 3)
 Disinfection byproducts (n = 4)
 Organic chemicals (n = 53)
 Radionuclides (n = 4)
Secondary Drinking
Water Standards:
Nuisance Chemicals

6. Current Status in US
 Significant population in US may be exposed to
inorganic contamination in drinking water such
as arsenic (As) and nitrate (NO3
-)
 Over 3.8 million population was reported to be
exposed to drinking water contaminated with
disinfection byproducts in 2009
https://www.cdc.gov/pictureofamerica/pdfs/pict
ure_of_america_drinking_water.pdf

7.  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

8. 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

9. 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

10. 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

11. Water Pollution Implications for Texas
Edwards Aquifer
 Located in South-Central Texas
 One of the most productive
karst aquifers in the United
States (180 miles long x 5-40
miles wide)
 Primary water source for city
of San Antonio and
surroundings (~ 2.3 million
people)

12. Being one of the fastest growing regions,
urbanization and industrial development may
affect Edwards Aquifer groundwater quality
 Currently, most
development within
San Antonio and
nearby region is on
the confining zone
of the Edwards
Aquifer
 This limits the
contaminant
transport into the
aquifer – for now
 Changes in land
usage may affect the
groundwater quality
adversely

13. 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

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

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

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

17. 17
How does arsenic mobilize?

18. Since 2020
UTSA’s Role in Water Science

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

20. Thank you !
Questions?

21.  44 million U.S. households depend on private wells for
drinking water
 Currently: Most private well owners do not test for As
 Dry regions and urban areas at highest risk
 Geochemical and hydrological/mobilization studies indicate
deeper wells at higher risk
 Sand and gravel aquifers displayed highest risk
 2.1 million people - U.S. public, private, and monitoring wells
exceed EPA standards (10 µg/l)
 HOT SPOTS: New England, California and western Nevada,
Texas panhandle and others – Any in Texas—San Antonio?
Arsenic in the US

22. Arsenic and Fluoride Leaching
Experiments under geothermal condn
US-Mexico
Collaboration,
student
exchange and
field research
Arsenic and Fluoride in Water

23. Synchrotron Aided µX-ray Spectroscopy
Chemical (Speciation)
Modeling
SEC +
ICP-MS
Tungsten Mobilization
 Tungsten
mobility using
geochemical
techniques was
studied
 Potential health
impacts on
society

24. Trace Element Biogeochemistry in
Waters
 Trace element speciation in natural
 Arsenic, tungsten, manganese, selenium, lead,
nitrates, and fluorides in the environment.
 Low-temperature aqueous geochemistry,
hydrogeology, and geomicrobiology.
Volcanic (lava tube) Caves Biogeochemistry
 Biogeochemistry and planetary sciences
 Speleothems formation processes
 Physical, chemical, and microbial processes in extreme
environments – planetary analogs
Hyporheic Zone Geochemistry
 Permeable natural reactive barrier
 Meghna riverbank in Bangladesh to
characterize PNRB
 Project involves field investigations, laboratory
experiments, and flow and reactive transport
modeling.
Lead in Children’s Blood – Use of isotopes
 Toxic levels of lead in children’s blood
 Use of lead isotopes for source tracking
 Collaboration with health professionals and geochemists
 This will help to facilitate targeted environmental
remediation.
Overview of Our Work at UTSA

25. Real-time Soil P Monitoring Sensor
 Using graphene sensors to monitor soil P in
pore water
 Mobilization of P in soils via physical, chemical
and microbial processes
 Influence of soil texture and properties on P
mobilization
Brackish Groundwater Desalination
 Brackish groundwater (TDS, 1,000 – 10,000 mg/L)
 An abundant and relatively untapped water source in the
U.S., particularly in the southwest and Texas.
 Using natural geochemical processes to improve
brackish water desalination
 Potable and non-potable water reuse
Wildfires and Caves
 Wildfires of high magnitude on surface
 Impacts on cave ecosystem
 Aquatic chemistry, microbial diversity and
activity
 Broader implications in understanding effects
of surface disturbances on subsurface systems
Edwards Aquifer Groundwater Quality and
Implications for US-Mexico Underserved
Borderline Communities
 Trace elements contamination in groundwater
 Access to safe drinking water to underserved
communities
 Impacts of land use
Overview of Our Work at UTSA

26. Mueller, J.T., Gasteyer, S. The widespread and unjust drinking water and clean water
crisis in the United States. Nature Communications 12, 3544 (2021).
https://doi.org/10.1038/s41467-021-23898-z
 Percent of active county community water systems
listed as Safe Drinking Water Act (SDWA) Serious
Violators.
 Note many counties in the state of Texas and borderline
states violated SDWA.
 ~489,836 households lack complete plumbing,
 1,165 community water systems (CWS) in SDWA
serious violation
 21,035 Clean Water Act permittees in Significant
Noncompliance.