Fish populations in the Pacific Northwest have declined as spawning grounds have disappeared because of river and stream barriers, often under-road culverts. This research investigated ways to incorporate different kinds of organic material inside a culvert that would both maintain the stream channel shape while also improving the ability of fish to successfully navigate those culverts during low water flow.

Recent emphasis on actions to reduce large-scale greenhouse gas (GHG) emissions has pushed most state departments of transportation to develop strategies to mitigate the adverse environmental impacts of the materials that they utilize. To assist WSDOT, researchers at the UW Carbon Leadership Forum assessed and analyzed the GHG emissions of WSDOT’s current material practices and explored opportunities to decrease them.

During roadway construction, transportation agencies frequently unearth industrial soil contamination that threatens both public health and the environment. Management of such compounds to meet environmental regulations can cause construction delays and increase costs. For this study, the researchers sought to develop an accelerated in situ treatment approach adaptable for use at any construction site to cost-effectively remove high-molecular-weight polycyclic aromatic hydrocarbons and metals from clayey soil.

During roadway construction, transportation agencies frequently encounter soils containing inorganic compounds that can pose a threat to human health and the environment. Management of such compounds to meet environmental regulations can cause construction delays and increase costs. The researchers in this study sought to develop an accelerated in situ electrochemical treatment for extracting inorganic compounds from fine-grained soils.

Fish populations have decreased in the Puget Sound area in part because fish barriers such as culverts have limited the ability of fish to swim upstream to reach their food supplies and spawning grounds. This project looked at better ways to maintain a common replacement for traditional culverts, stream simulation culverts.

Flora of the Pacific Northwest, 2nd Edition, published in October 2018 by the University of Washington Herbarium, Burke Museum, provides users with dichotomous keys to 5,085 wild-growing Pacific Northwest native and introduced plant species. This project expanded the existing Flora 2nd edition website to include automatically updating distribution maps for all taxa in the book and produced revised identifications keys for families, genera, and species that have undergone taxonomic changes.

Transportation agencies need cost-effective tools to address stormwater pollution. In cold climates that require the use of a lot of snow/ice control products, chloride salts are a particular problem in highway runoff. This project assessed the use of crushed fines from recycled concrete (CFRCs), modified with nano silicon dioxide, to passively remove chlorides from polluted stormwater runoff.

Pervious concrete holds great potential to mitigate the effects of deicers in stormwater runoff in cold regions and to support environmental conservation. This study provided a better understanding of the freeze/thaw and salt scaling resistance of pervious concrete modified with fly ash, with or without graphene oxide.

In the Pacific Northwest, elevated soluble zinc and copper concentrations originating from urban stormwater runoff pose a significant threat to native salmon and steelhead populations. In response to urbanization, existing stormwater infrastructure needs to be upgraded to treat non-point source pollution, including soluble metals, before they enter receiving waters. This project aimed to provide sustainable design suggestions for urban stormwater remediation at Washington State Ferry terminals. Researchers conducted laboratory and field-scale column tests to recommend specific types of plant filtration media for copper and zinc adsorption.