If you were to picture what makes Seattle such a special place to be, what might you imagine? Whether your response summons the lush evergreen trees, fresh seafood, beautiful Puget Sound views, infamously misty days, or something entirely different, there’s a good chance that your answer connects back in some way to our region’s rainy climate. Unfortunately, due to increasing climate change and urban development pressures, the quality and quantity of the water that we depend on has been drastically impacted by stormwater runoff.
When rain and snow melt over the Puget Sound region, this picks up pollution (like oil, fertilizers, dust from tires, copper, zinc, pesticides and trash) as it washes off buildings, streets and highways before flowing directly into our streams, lakes and marine waters. Just as the rain has a way of reaching through even the most durable rain coats if our exposure to the elements is long enough, so too do the effects of stormwater runoff have a way of touching all of the fibers weaving our community’s health and wellbeing together.
“Stormwater is the single biggest source of pollution across aquatic environments in the Puget Sound and in Lake Washington,” shared Ericka Hegeman, GIS Research Scientist at UW EarthLab. In fact, just one acre of pavement can put a million gallons of polluted runoff into the Puget Sound annually. “We know it’s a huge problem for fish in particular, but stormwater runoff impacts everyone in the food chain from primary producers like algae and plants to the whales who feed on local salmon and to humans in the area.”
As our region continues to expand in both population (including cars on our roads) and industry, this problem will only magnify. In order to create lasting mitigation strategies to ease the burden of stormwater runoff on our health and environment, we first have to ask: where are our most polluted areas and how do we better prioritize our mitigation efforts?
The Role of Redlining in Community Pollution
Although the negative impacts of stormwater pollution touch us all, they don’t impact us equally. Ericka is part of UW Professor of Practice and Lead Scientist for the Nature Conservancy Phil Levin’s research team that is currently at work on a stormwater mitigation project. This team is mapping Seattle’s areas of high pollution alongside regional health data provided by the Washington State Department of Health Environmental Health Disparities Map to learn more about where improved environmental health will have the greatest impact.
“We know that the Seattle areas most impacted by pollution are often BIPOC communities,” said Ericka. “In fact, communities of color are at a disproportionate risk from experiencing stormwater pollution in comparison to white communities.”
For example, the 98188 zip code is one of the most diverse areas in the country, and it also experiences disproportionately higher levels of pollution compared to zip codes dominated by white residents.
Despite changing demographics, historically redlined areas from the early 20th century onwards continue to have a significantly hazardous impact on the animals, humans and the natural environment, which speaks to the need to target mitigation efforts first and foremost in these communities.
“By linking the pollution loading in certain locations with the potential for stormwater solutions to mitigate specific pollutants, we’re hoping to help reduce overall environmental health disparities currently faced in the area,” shared Phil.
A new model to better map stormwater mitigation plans
The framework that Phil and Ericka’s team are developing ultimately aims to provide a systematic approach to improve community health through multiple levers of impact.
This project was partially inspired by The Nature Conservancy’s Water 100 Project, which identified the top 100 most substantive solutions to create a cleaner and more resilient Puget Sound. These foundational mitigation strategies built a movement for the current GIS mapping model to help address dynamic solutions across a variety of environmental and human health indicators.
“Part of what makes this project unique is that we are focused on the many benefits of potential solutions rather than the isolated benefits from a singular approach to improving water quality,” We are seeking solutions that are good for nature and people,” said Phil. Mapping data from this project can help provide information on the critical areas for infrastructure improvements. For instance, investing in green infrastructure (such as planting more trees, building swales – shallow channels made to collect and slowly release water – and creating home rainwater-harvest systems) can improve water quality by removing pollutants from the air naturally before they can transform into toxic stormwater runoff. In this case, water quality is improved, while simultaneously alleviating health disparities resulting from better air quality, such as asthma or even heart disease.
As Ericka explained, “Green stormwater infrastructure is about making the urban landscape better by improving people’s lives and the environment at the same time.”
By examining the impacts of physical, mental and environmental health disparities alongside stormwater mitigation solutions, researchers are able to exact and scale new data that provides insights into where our city infrastructure investments are needed most– for both our environment and the people living within it.
This project has been generously funded by Boeing. To learn more about this area of work, please visit Phil Levin’s lab website.