In this episode Talking Under Water co-host Mandy Crispin speaks with Brent Alspach, Vice President and Director of Applied Research at Arcadis, about the evolving science of microplastics in drinking water and the challenges facing future regulation. Recorded at ACE26, the conversation explores what has changed over the past year in the industry's understanding of microplastics and why policymakers, utilities, and researchers are still searching for answers.

Brent explains why defining microplastics for regulatory purposes is far more complex than defining traditional contaminants, given the wide range of particle sizes, polymer types, and characteristics involved. He also discusses concerns that public and political pressure could outpace the scientific research needed to support effective regulations.

The discussion covers the many hurdles that remain before any federal drinking water standard could be developed, including the lack of standardized sampling methods, testing protocols, and health effects data. Mandy and Brent also examine how regulators might determine whether drinking water is a significant source of human exposure compared to food or air.

Finally, Brent shares insights into how existing treatment processes perform, where knowledge gaps still exist, and what utility leaders should be doing today to prepare for a future in which microplastics receive greater regulatory attention.

WaterWorld AWWA ACE26 Show Coverage

• 00:00 – Introduction
• 01:41 – What qualifies as a microplastic and why terminology matters
• 02:24 – Why science must catch up before regulation advances
• 04:03 – The challenge of defining microplastics for regulatory purposes
• 07:47 – Determining whether drinking water is a meaningful exposure source
• 09:38 – How far away meaningful regulation may be and the hurdles that remain
• 11:30 – Can current drinking water treatment processes remove microplastics?
• 15:51 – Housekeeping

About the Podcast

Talking Under Water is the premier podcast for the water industry, including municipal water and wastewater, residential water treatment, storm water management and erosion control. It is produced in coordination between Wastewater Digest (WWD), WaterWorld and Stormwater Solutions (SWS). The podcast covers topics under the One Water movement including the municipal and industrial water and wastewater, residential, stormwater and erosion control markets. Talking Under Water highlights news, trends, new technologies, industry discussions and interviews with experts across the municipal water industry. New episodes of the podcast are released every other week. Logo Images: Anatoly Tiplyashin / Romolo Tavani / stock.adobe.com.

Contact the Talking Under Water podcast editors by emailing talkingunderwater@endeavorb2b.com engaging with them on X @TUWpodcast. Join the conversation by commenting or using the hashtag #talkingunderwaterpod on social media.