EPISODE TWO: SHOW NOTES
Dilution may not be the solution: The global footprint of wastewater pollution
Featuring Dr. Ben Halpern (UC Santa Barbara) and Dr. Cascade Tuholske (Montana State University)
LISTEN ON: Apple Podcasts ◦ Spotify ◦ YouTube
LISTEN ON: Apple Podcasts ◦ Spotify ◦ YouTube
Where does our wastewater really go—and what is it doing to our oceans? In this episode of The Nature Conservancy’s waste(d)water podcast, host Kassie Morton speaks with Drs. Cascade Tuholske and Ben Halpern about their groundbreaking global model that maps nitrogen and pathogen pollution from human sewage for over 135,000 watersheds. Discover how 25 of these watersheds contribute nearly half of the world’s wastewater nitrogen, why even advanced treatment systems can harm ecosystems, and how our diets play a surprising role. This eye-opening conversation reveals the hidden scale of wastewater pollution and offers hope through data-driven solutions for healthier oceans and communities.
wastewater pollution, ecological health, nutrient pollution, marine ecosystems, wastewater management, public health, environmental health, global analysis, nitrogen inputs, conservation strategies
- Wastewater pollution has been largely underestimated.
- 80% of the world's wastewater is discharged untreated.
- 25 watersheds are responsible for nearly half of global nitrogen inputs.
- Wastewater contributes significantly to coastal nutrient pollution.
- Agricultural runoff is often prioritized over wastewater pollution.
- Improving sanitation is essential for public health.
- Dietary choices, especially protein consumption, impact wastewater pollution.
- Understanding the sources of wastewater is crucial for effective solutions.
- Communities can leverage research to address local wastewater issues.
- Collaboration across sectors is key to solving wastewater challenges.
Dr. Cascade Toholske is Assistant Professor at University of Montana where he teaches human-environment geography, climate change risks and impacts, and geospatial data science for sustainability. With a Ph.D. in geography, his research focuses on linkages between climate change, food security, and urbanization.
Dr. Ben Halpern is Professor of Marine Biology and Conservation Science at the Bren School of Environmental Science & Management at UC Santa Barbara and Director of the National Center for Ecological Analysis and Synthesis. With a Ph.D. in marine ecology, Dr. Halpern is a conservation scientist with broad, interdisciplinary expertise in climate change science, ecology and evolution and marine conservation, policy and education.
00:00 Understanding Wastewater Pollution's Ecological Impact
02:29 The Global Scope of Wastewater Pollution
05:10 Sources and Consequences of Nutrient Pollution
08:31 Wastewater Management Disparities
11:22 Key Contributors to Global Wastewater Nitrogen Inputs
14:18 Comparing Wastewater and Agricultural Runoff
17:27 Infrastructure and Its Role in Pollution
20:06 Future Research Directions
23:20 Balancing Public Health and Environmental Health
26:07 Community Solutions and Global Collaboration
29:16 Individual Actions and Dietary Considerations
31:40 Final Thoughts on Wastewater Management
Mapping Global Inputs and Impacts from Human Sewage in Coastal Ecosystems
Tuholske et al., PLOS One, 2021
Read the article
Wastewater Pollution: The Problem - Scale of Pollution
Ocean Sewage Alliance
Explore the resource
Wastewater Pollution Impacts on Estuarine and Marine Environments
Treatise on Estuarine and Coastal Science, 2nd Edition – Chapter 6.13
Access the chapter
Wear & Vega Thurber, 2015
Read the paper
Water, Sanitation, Hygiene, Environmental Cleaning and Waste Management in Health Care Facilities
UNICEF & WHO, 2020 – 2023 Data Update
View the report
Identifying Wastewater Management Tradeoffs in Kona, Hawai‘i
Wada et al., PLOS One, 2021
Read the article
CREDITS
Post-production services for waste(d)water provided by Two Aspen Audio. A special thank you to The Nature Conservancy Coda Fellows Sydney Bezanson and Juan Sebastián Gómez Gutiérrez for their contributions.