Surreal illustration of a subterranean environment with microbial networks.

Is Your Drinking Water Safe? Uncover the Hidden World of Subsurface Microbes

Lena Voss in Climate & Environment August 2025 • 4 min read.

"A Deep Dive into Microbial Transport and Groundwater Contamination"

The unseen world beneath our feet teems with life, especially microorganisms. While often overlooked, these tiny organisms play a crucial role in our environment, particularly in subsurface environments like soils and aquifers. Understanding how these microbes move and change (their transport and fate) is essential, especially when it comes to protecting our drinking water.

This is because the subsurface can act as a pathway for pathogens – harmful microorganisms that can make us sick. These pathogens, often introduced through human activities, can contaminate groundwater, which serves as a primary drinking water source for a significant portion of the global population. On the flip side, harnessing the power of beneficial microbes in the subsurface holds promise for environmental cleanup. Optimizing their use in bioremediation could help us tackle pollution and restore our ecosystems.

Inspired by the Ninth International Symposium for Subsurface Microbiology in 2014, recent research efforts are shedding light on the occurrence, transport, and fate of microorganisms in these complex environments. This research aims to improve our ability to protect drinking water resources and use in situ environmental remediation.

The Hidden Risks: How Microbes Contaminate Our Groundwater

Surreal illustration of a subterranean environment with microbial networks.

Groundwater contamination by microorganisms is a serious concern. Consider these facts:

Half of the global population relies on groundwater as their primary source of drinking water. In many regions, it also provides a significant portion (43%) of the water used for irrigating fresh produce. This heavy reliance makes groundwater contamination a direct threat to public health.

Sources of Contamination: Surface water and wastewater, even after treatment, can still contain microorganisms that infiltrate groundwater resources.
Pathways to Exposure: Pathogens can find their way into our drinking water through various pathways. Some are due to recreational exposure to surface water.
Disease Outbreaks: Numerous waterborne and foodborne disease outbreaks have been linked to contaminated groundwater supplies.

While water treatment processes like riverbank filtration and managed aquifer recharge aim to remove pathogens, their effectiveness isn't always guaranteed. Pathogens have been detected in both shallow and deep groundwater wells, highlighting the need for a deeper understanding of how these microorganisms behave in the subsurface.

Looking Ahead: Protecting Our Water Resources

By enhancing in situ environmental remediation and to assess the risk to, and protection of, our water resources from microbial contamination, findings from research identifies critical gaps in knowledge, conditions of increased risks, and limitations of models. It's a call to action for researchers and policymakers to invest in further studies, refine existing models, and develop innovative solutions for safeguarding our water resources. Through continued efforts, we can ensure access to safe and clean drinking water for all.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.2134/jeq2015.07.0375, Alternate LINK

Title: Microbial Transport And Fate In The Subsurface Environment: Introduction To The Special Section

Subject: Management, Monitoring, Policy and Law

Journal: Journal of Environmental Quality

Publisher: Wiley

Authors: Scott A. Bradford, Jack Schijven, Thomas Harter

Published: 2015-09-01

Everything You Need To Know

What is the primary concern regarding microorganisms in subsurface environments?

The primary concern is the potential for microorganisms, specifically pathogens, to contaminate groundwater, which is a vital source of drinking water for a large portion of the global population. These subsurface microorganisms can act as a pathway for harmful pathogens, leading to contamination of groundwater resources, posing a direct threat to public health.

How do microorganisms get into our drinking water and what are the risks?

Microorganisms can enter groundwater through various pathways, including surface water and wastewater, even after treatment. The risks are significant. These pathogens can cause waterborne and foodborne disease outbreaks. Also, the heavy reliance on groundwater for drinking water and irrigation of fresh produce (43%) exacerbates the risk, as contamination directly affects public health and food safety.

What are the limitations of current water treatment processes in removing subsurface microorganisms?

Even advanced water treatment processes such as riverbank filtration and managed aquifer recharge aren't always fully effective in removing all pathogens. This highlights the need for a deeper understanding of how microorganisms behave in the subsurface and how to mitigate their impact on drinking water sources. The presence of pathogens in both shallow and deep groundwater wells underscores the need for improved strategies.

Can beneficial microbes be used to improve our environment?

Yes, harnessing the power of beneficial microbes in the subsurface holds promise for environmental cleanup. Optimizing their use in bioremediation could help tackle pollution and restore ecosystems. This approach aims to utilize the natural capabilities of these microorganisms to break down pollutants, offering a sustainable method for environmental restoration.

What efforts are underway to protect our water resources from microbial contamination?

Research efforts, inspired by events like the Ninth International Symposium for Subsurface Microbiology in 2014, are focused on understanding the occurrence, transport, and fate of microorganisms in subsurface environments. This research aims to improve our ability to protect drinking water resources and use in situ environmental remediation. Further studies, refining existing models, and developing innovative solutions are critical for safeguarding our water resources.