Protection of Precious Waters from Road Salt: Mitigation Through Roadside Ditch Capture
Roadway deicers are essential to the functioning of daily life in northern states in winter. After plowing, roadway salting is currently the most practical way of making safe transportation possible in winter. However, road deicer chloride (salt) has a severe negative effect on surrounding watersheds. Yet, currently no methods or procedures have been developed to capture the chloride. The situation is particularly dire where highways cross small receiving streams that are the habitat of endangered and threatened species, such as the Topeka Shiner, because the high concentration of chloride in the highway runoff does not dilute sufficiently to prevent toxicity in the hatching and juvenal rearing areas of the streams. This project developed in-ditch salt capture techniques based on mitigation of chloride migration through absorption and capture in a manufactured backfill media. Chloride mass in drainage water was observed and monitored at a range of concentrations before and after percolation through granular soil mixtures “manufactured” to capture chloride and deployed in flow-through sandbags. Absorbance of chloride was quantified by manufactured soil sandbags in ditch-deployed configurations, allowing optimization of the deployed geometry. Field test installation approaches were designed and tested for chloride capture from actual winter maintenance operations.
- Record URL:
Language
- English
Project
- Status: Completed
- Funding: $312,375.00
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Contract Numbers:
1052639
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Sponsor Organizations:
Minnesota Department of Transportation
395 John Ireland Boulevard
St Paul, MN United States 55155 -
Managing Organizations:
Minnesota Department of Transportation
Office of Research & Innovation
395 John Ireland Boulevard, MS 330
St. Paul, MN United States 55155-1899 -
Performing Organizations:
Minnesota State University, Mankato
Center for Transportation Research and Implementation
342 Trafton Science Center
Mankato, MN United States 56001 -
Principal Investigators:
Druschel, Stephen
- Start Date: 20230713
- Expected Completion Date: 20270228
- Actual Completion Date: 20260323
Subject/Index Terms
- TRT Terms: Backfill soils; Chloride content; Deicing chemicals; Ditches; Roadside; Runoff
- Subject Areas: Environment; Highways; Hydraulics and Hydrology; Maintenance and Preservation;
Filing Info
- Accession Number: 01961158
- Record Type: Research project
- Source Agency: Minnesota Department of Transportation
- Contract Numbers: 1052639
- Files: RIP, STATEDOT
- Created Date: Jul 18 2025 11:30AM