Did you know that most trash that ends up in the river comes from the streets? Every time it rains, plastic bottles and wrappers, and other items are carried down a storm drain on the road then straight to the nearest waterbody.
So figuring out how to keep trash out of the river means first figuring out where it is concentrated on the land in our highly urbanized, highly paved landscape.
One tool we have is EPA’s Visual Trash Assessment (VTA) protocol, which gives a way to compare trash densities on roads in different parts of the city.
MyRWA collected a series of trash data last spring with the help of more than 20 volunteers. The main goal of this research was to validate the Virtual Trash Assessment conducted in 2018.
Like in 2018, the 2021 results demonstrated that industrial, multi-family residential, and commercial areas had far more trash than residential neighborhoods (medium- and high-density) with separate houses. Similarly, open spaces such as cemeteries, forests, and open lands had the least trash.
The map shows the trash rating for streets and paths for amount of trash, using protocols defined by EPA ( Lower grades represent more trash).
The 2021 survey acts as a kind of repeatability test for the survey method. In our baseline water quality sampling, for instance, we get "field duplicates" every time we go out, to make sure our sampling method yields consistent results.
What these results suggest for VTA is that if you assign a random group of volunteers at random times in two different years, they will deliver comparable results. The results give us confidence in the power of this method to pick up a signal in the environment and acquire data that can inform policy.
The next step will be to repeat the exercise with new routes and compare the results. If they point in the same direction, we should be confident in our current hypothesis: The biggest source of trash in the stormwater system is from commercial/industrial/multi-family residential land use areas, and municipalities should concentrate their management efforts--high-intensity street sweeping, increased trash cans, etc.-- there.
Stay tuned for volunteer opportunities to help us gather this important data.
