Physical Sciences and Mathematics Commons^™

Water Quality Analysis Of Ecoroof Runoff In Portland, Pranoti P. Deshmukh

Civil and Environmental Engineering Master's Project Reports

Portland, Oregon is internationally recognized for its implementation of sustainable stormwater management technologies. Ecoroof is one of the sustainable solutions to reduce stormwater runoff which also provides multiple environmental benefits. However, very little is known about the impact of ecoroofs on water quality of roof runoff. Stormwater runoff carries a significant amount of pollutants, which, if it directly enters a stream or river, degrades water quality and severely harms aquatic life.

This study evaluates the trends in the long-term water quality data from ecoroofs and conventional roofs in the Portland area. Mann Kendall trend test was used to detect the …

Long-Term Variation Of Summer Phytoplankton Communities In An Urban Lake In Relation To Lake Management And Climate Conditions, Yuan Xiao Grund

Dissertations and Theses

Eutrophication is one of the primary factors causing harmful cyanobacteria blooms in freshwater lakes; climate change such as warmer temperature can potentially further increase both frequency and intensity of blooms. This study investigated the long-term changes in water quality and summer phytoplankton assemblages in Oswego Lake, OR, in relation to lake management practices (e.g., hypolimnetic aeration and alum treatments), as well as climatic and regional meteorological conditions. Both water quality and phytoplankton assemblages were sampled biweekly during summer seasons between 2001 and 2013. The concentrations of total phosphorus (TP), soluble reactive phosphorus (SRP) and total nitrogen (TN) decreased 66%, 93% …

Using Wetlands To Prevent The Surface Accumulation Of Aphanizomenon Flos-Aquae From Upper Klamath Lake, Arick Christopher Rouhe

Dissertations and Theses

The ability to regulate buoyancy (sinking and floating) using cellular gas vesicles is a unique characteristic that allows many common bloom-forming cyanobacteria to accumulate at water surfaces and dominate systems. Typical control and management strategies include nutrient manipulation and phosphorus reduction, which are effective but do not reduce the advantage of buoyancy control. Since buoyancy control is based upon a mechanism that is driven by photosynthesis along with environmental conditions that trigger vesicle formation and ion exchange, buoyancy regulation can be influenced by manipulating extracellular conditions. In this study I manipulated extracellular conditions using wetland water and additions of potassium, …

Hydrological Patterns And The Effects Of Land Use On Tss Concentrations And Yields In The Mccarthy Creek Watershed, Portland, Oregon, David Farmer

Environmental Science and Management Professional Master's Project Reports

The spread of impervious surface areas and the reduction of tree canopy via urbanization has numerous water quality impacts on Pacific Northwest watersheds. One such impact is elevated levels of Total Suspended Solids (TSS) in run-off during storm events, particularly in steep, forested watersheds undergoing urbanization. This project was developed in collaboration with the West Multnomah Soil and Water Conservation District and focused on the McCarthy Creek Watershed, as a case-study watershed located in Portland, OR. The study aimed to identify elevated TSS concentrations and yields during storm events on both mainstem and tributary sampling locations, establish the relationship between …