Many of us have seen news about cyclospora or may even know someone who has been affected by it. The recent outbreak has understandably raised questions about this pathogen, how it spreads and what it means for the safety of our food and water in El Paso.

Karla Mendez

Those are reasonable questions. As a public health researcher who studies water quality and microbial risk, I take concerns about pathogens seriously. I also live in El Paso and work with El Paso Water on research and public education. For me, the safety and quality of our water is both professional and personal.

Cyclospora cayetanensis is a microscopic parasite that can cause an intestinal illness known as cyclosporiasis. It can be spread through food or water contaminated with human fecal material and may be resistant to conventional disinfection methods such as chlorination. But, importantly, detecting a pathogen in wastewater doesn’t mean it is present in treated drinking water. What matters is what happens to that water between the source and the consumer.

It’s that process that gives me confidence in El Paso’s water supply. El Paso Water continuously monitors its treatment system performance and conducts regular testing for pathogens, chemicals and other indicators in the water. Its treatment facilities operate to meet or exceed water quality standards, and the utility works with public health agencies and academic researchers to better understand emerging risks. 

Water safety is not something that is checked just once. It’s an ongoing process of treatment, monitoring, testing and adapting as new threats and the science to combat them evolve.

Now under construction, the Pure Water Center will create a new source of drinking water for El Paso by taking treated wastewater through advanced purification before it enters the drinking water system. 

Advanced water purification goes well beyond conventional wastewater treatment, using sophisticated treatment technologies to remove or inactivate microorganisms and other contaminants. The process includes membrane filtration, reverse osmosis or nanofiltration, ultraviolet disinfection and granular activated carbon. 

Simply put, wastewater may be where the water begins, but it is not what comes out of the tap. 

The Pure Water Center is being developed around a fundamental public health principle of multiple barriers. I sometimes explain this using the “Swiss cheese model.” Each slice represents a different treatment barrier, and each hole represents potential vulnerabilities. One slice alone has weaknesses but with several slices stacked together, those weaknesses are much less likely to align. For a contaminant to make it all the way through, it would have to overcome every barrier in the treatment process. 

That redundancy is important not only for cyclospora, but also for contaminants we may encounter in the future. We cannot predict every pathogen or chemical that may become a concern, but the goal is to have a treatment and monitoring system capable of responding as our understanding of water-quality risks evolves. 

As residents, we should ask questions about our water. Understanding where it comes from is important, but it is only the starting point. We should also understand how risks are identified, how water is treated, how quality is verified and how our water system responds when new information emerges. I have spent my career studying water quality and public health, and I know no water source exists in a perfectly controlled environment. What matters are the protections we put between the source and our tap. 

That is one of the reasons I have strong confidence in our water utility. I have seen firsthand an organization that takes its responsibility for public health seriously, that listens to the concerns of the community and continues to invest in the technology needed to protect our water. El Paso Water recognizes that earning the community’s trust requires transparency and an ongoing conversation about where our water comes from and how it is made safe.

The Pure Water Center is the next chapter in that commitment. It combines proven treatment barriers with continuous monitoring, research and the expertise of people whose job is to protect public health. As a scientist, those safeguards give me confidence. As an El Pasoan, so does knowing that the people responsible for our water are asking the same questions we are, preparing for risks and working every day to provide our community with safe, reliable water.

Karla S. Mendez is an assistant professor at UTHealth Houston School of Public Health specializing in water quality and quantitative microbial risk assessment. Her research focuses on evaluating public health risks associated with wastewater reuse and the factors that influence community acceptance of water reuse.