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Engineering Commons

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Environmental Engineering

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Portland State University

Series

2021

Urban runoff -- Management

Articles 1 - 2 of 2

Full-Text Articles in Engineering

Exploring How Antecedent Precipitation Amount And The Effects Of Covid-19 Affect Stormwater Runoff Quality Along Urban Gradients, Daniel Ramirez, Katherine Gelsey Aug 2021

Exploring How Antecedent Precipitation Amount And The Effects Of Covid-19 Affect Stormwater Runoff Quality Along Urban Gradients, Daniel Ramirez, Katherine Gelsey

REU Final Reports

Stormwater runoff quality is affected by a multitude of factors including surrounding land characteristics, human activities, and antecedent precipitation amounts. We explore how seasonal and variable precipitation affect E. Coli, total suspended solids, nitrogen-nitrate, orthophosphate, lead, and zinc concentrations in Portland, OR, USA. Correlation analysis was conducted between the pollutant concentrations and antecedent rainfall each sample site received for the previous 1, 3, 5, 7, and 30 days from when the sample was taken. We ran Mann-Whitney tests to determine if the levels of the pollutants were statistically different between the wet season and the dry season. We found that …


Modeling The Effectiveness Of Cooling Trenches For Stormwater Temperature Mitigation, Scott A. Wells Jan 2021

Modeling The Effectiveness Of Cooling Trenches For Stormwater Temperature Mitigation, Scott A. Wells

Civil and Environmental Engineering Faculty Publications and Presentations

Due to elevated runoff stormwater temperatures from impervious areas, one management strategy to reduce stormwater temperature is the use of underground flow through rock media termed a cooling trench. This paper examines the governing equations for the liquid phase and media phases for modeling the temperature leaving a cooling trench assuming that changes in temperature occurred longitudinally through the cooling trench. This model is dependent on parameters such as the media type, porosity, media initial temperature, inflow rate, and inflow temperature. Several approaches were explored mathematically for evaluating the change in temperature of the water and the cooling trench media. …