Project Partner: Charles River Watershed Association, Spring 2026

Project Summary: Ethan worked with the Charles River Watershed Association (CRWA) and their River Science Extern, Marielena Lima, to conduct monitoring and analysis of Charles River tributaries. The reason for ongoing monitoring is the negative impact salinization (the increased concentration of ions and salts in water bodies) has on freshwater ecosystem health and drinking water quality. The source of chloride and other salts in urban environments is mostly the spread of road salt for winter transportation safety. In many cases, salting practices can be improved to limit the damages done to freshwater bodies, therefore the goal of this internship was to help continue the monitoring of chloride levels in rivers and streams in order to better understand the spatial and temporal changes throughout the watershed. During his internship, Ethan contributed to data collection from January – March 2026 from the Muddy and Stop Rivers, Bogastow Brook, and Cheesecake Brook. Using Environmental Protection Agency criteria, he then conducted data analysis to see which times and locations exceeded chloride thresholds acceptable for aquatic organisms. This is an ongoing monitoring project, but part of the goal accomplished during Ethan’s time at CRWA was to clean and obtain data trends that can then be used to inform policy changes, or to better understand the state of human interaction and intervention with urban freshwater environments, which is often overlooked. Ethan plans to continue using the collected data for ongoing research, and will continue to participate in Technical Advisory Group meetings that aim to address overuse of salt, with the guidance of CRWA.

 

Deliverables:

  • Collection and analysis of chloride levels in water samples from monitoring sites across the Charles River Watershed
  • Internal presentation of findings to Charles River Watershed Association staff
  • Provide analysis and conclusions from data collection to Cambridge Technical Advisory Committee focused on local policy to reduce oversalting

 

Watch Ethan’s URBAN Internship lightning talk here.