Water Quality Benefits of Pervious Pavements
Jackson Kaye
Permeable pavements have the potential to be a useful tool for mitigating stormwater runoff from streets in urban areas. However, there is concern that pollution from stormwater can potentially infiltrate and pollute water pipes under permeable streets. This research will evaluate the water quality of stormwater that flows through permeable pavements. Two types of permeable pavement will be tested: pervious concrete and porous asphalt. Test specimens will be made in triplicate, and allowed to cure. Stormwater will be collected and used to conduct 5 tests on each specimen. Influent and effluent samples will be taken throughout the duration of the tests, and analyzed for copper, zinc, total nitrogen, ammonia, nitrate, total phosphorus, phosphate, turbidity, and pH. Influent and effluent results will be compared to evaluate pollutant removal. We hypothesize that permeable pavements will decrease pollutant levels enough to meet drinking water standards and minimize risk of polluting water pipes.
Evaluation of Biochar for Metals, Nutrient, and Microplastics Removal in Bioretention Systems
Maya Struzak and Abby Radke
Bioretention has is a common green stormwater infrastructure method that slows and reduces runoff to receiving waters or wastewater treatment plants, and removes pollutants. However, metals removal is sometimes insufficient to protect aquatics species, and nutrients are often exported from bioretention systems. In addition, very few studies have evaluated the efficacy of bioretention for microplastics removal. Biochar is often used as an amendment in bioretention systems, but very few studies have quantified water treatment benefits of including biochar.
This study will evaluate metals, nutrient, and microplastics removal with column experiments. Three columns will have the City of Portland standard bioretention mix (control), three will have 25% biochar and 75% City of Portland standard bioretention mix, and three will have 50% biochar and 50% City of Portland standard bioretention mix. Stormwater will be collected and used to conduct 5 tests. Influent and effluent samples will be taken throughout the duration of the tests, and analyzed for copper, zinc, total nitrogen, ammonia, nitrate, total phosphorus, phosphate, turbidity, pH, and microplastics. Influent and effluent results will be compared to evaluate pollutant removal.
