Environmental and Water Resources Institute
​The Colorado Environmental and Water Resources Institute (EWRI) Chapter is committed to advancing the fields of environmental and water resources. Currently, the chapter is focused on revitalizing its presence and increasing local engagement. As part of these efforts, we plan to host quarterly presentations to foster knowledge sharing and professional development. We are actively seeking speakers and sponsors for upcoming events. If you are interested in supporting the chapter—whether by joining the revitalization team, sponsoring an event, or serving as a speaker—please contact the current Chair, Tasha Neel, at ewri@ascecolorado.org for more information.
NEWS
​Interactions and Treatment of Metals in Urban Stormwater
Presentation - Tuesday, March 3rd, 2026 - 5:30 - 7:30 MT
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Urban stormwater contains a cornucopia of pollutants that pose direct toxicity risks (e.g., metals, organics, pathogens) and indirect adverse effects (e.g., sediments, nutrients) to aquatic life. Metals, specifically copper (Cu) and zinc (Zn), are both ubiquitous in the urban environment and detrimental to aquatic ecosystems at low concentrations (approximately 10 ppb). Targeting this growing source of pollution upstream is critical in providing necessary environmental protections, especially as the intensifying effects of climate change and urbanization are imminent.
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Bioretention is a stormwater control measure (SCM) that mimics natural systems to take advantage of the natural filtering processes. In addition to hydrologic benefits, bioretention provides removal of particulate matter (PM) through filtration and sedimentation, and potential removal of dissolved constituents through chemical and biological processes. Studies including characterization of stormwater, road-deposited sediments (RDS), and performance of a mature bioretention cell were performed to determine treatability, mobility, and bioavailability of Cu and Zn in stormwater and through bioretention treatment. The mature bioretention cell was effective at reducing PM and particulate bound metal loads, but dissolved constituents went unchanged through bioretention treatment.
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Alternative media amendments were investigated for further reduce dissolved metal loads. Black carbon media including biochar, granular activated carbon, regenerated activated carbon, and a natural mineral sorbent, clinoptilolite zeolite, were tested in continuous columns, and in up-scaled modular treatment columns. The four tested BC media performed similarly for Cu and Zn removal, with Zn having an earlier breakthrough compared to Cu. Modular treatment columns showed that traditional bioretention soil media provided effective removal of dissolved Zn and ineffective removal of Cu. The subsequent BC polishing module was effective for Cu removal, and zeolite showed potential for Zn removal.
Overall, dissolved metals in stormwater are the most mobile, bioavailable, and difficult to remove through traditional filtration-based SCMs. This research showed potential applications for extending the life of filtration-based SCMs and incorporating media amendments to enhance dissolved metals removal
Please register here!
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https://collaborate.asce.org/events/simple-registration?CalendarEventKey=4b06f4de-5d7c-4ef8-8e3f-019c48fe009d
Any questions? Please reach out to Tasha Neel (ewri@ascecolorado.org)
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PAST EVENTS
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Holiday Sweater Social with CASFM - December 2025
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August 2025 Technical Meeting
The August 13, 2025 technical meeting discussed PFAS—those “forever chemicals” making waves in environmental and regulatory circles. Dr. Conner Murray, Hazen and Sawyer’s national PFAS expert, broke down where PFAS come from, how they move through the environment, and what utilities are doing to remove them from our drinking water. We provided 1 PDH for attending!
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​​​November 2024 Technical Meeting​
The November 6, 2024 EWRI technical meeting featured Rick Koehler presenting on Enhanced Flow Duration Curves (eFDCs), a new method that adds autocorrelation analysis to traditional FDCs to reveal daily streamflow dynamics. This innovation enables visualization of changes in streamflow magnitude, frequency, and persistence, offering valuable insights for hydrologic modeling, restoration, and monitoring.
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June 2024 Technical Meeting​
Holly Piza gave a fantastic presentation to our members June of 2024. Make sure you follow our emails to attend our next event!
