A major problem, as in many waterways in urban areas, is trash. The Restoration team is responsible for the innovative trash trap installed at Nash Run. This is one way the AWS Restoration team is actively cleaning the river. Most notably, we sort and measure the trash collected in order to plan for advocacy goals. The data collected at AWS trash traps has helped pass the bag fee law in DC and Montgomery County, MD (and measured its efficacy), the plastic straw bans in DC, Montgomery and Prince George’s counties, and the Styrofoam bans in DC, Montgomery, Prince George’s counties and the State of Maryland.
The Nash Run Trash Trap project was started as a response to this problem with the support and funding of the District Department of the Environment. The goal is to capture trash before it enters the main tidal Anacostia. The trash trap was installed around the mouth of Nash Run, which is the entrance to Kenilworth Marsh. Via this marsh, the water and trash flow into the tidal Anacostia, making it a good location to proactively catch the trash.
In February 2009, our first trash trap was installed. Although extremely effective, there was clogging in the trap and some trash still got through the barrier. Our observation and experience of the trap over the next two years gave us the knowledge to improve the effectiveness of the design. The new trap is gently angled at 5 degrees to the ground. The stream force is used to push up trash, leaves, and branches on the screen to suppress the clogging. This allows stream water to flow through the trap as smoothly as possible. The modified and improved design was installed in June 2011. Since then, we have added one more trash trap at River Terrace, south of Nash Run.
Results
The first design captured approximately 3,300 lbs of “pure trash,” meaning bottles and cans are emptied and organic matter such as leaves was removed, between February 2009 through June 2011. Trash was sorted into 47 categories for the first 2 years and the data on weight, number of pieces were collected. Then, the sorted trash was bagged into three major categories to allow AWS staff to study the trash characteristics by volume. Findings during the first 2 year study showed about 45% of trash was bottles and cans and 22% of trash was styrofoam. The detailed report is availabe online (https://doee.dc.gov/publication/demonstration-trash-reduction-technologies).
AWS has been persistently and patiently continuing to collect the data. The most recent volume analysis shows that only 1% is Styrofoam thanks to the Styrofoam bans in DC, Prince George’s Montgomery Counties and Maryland. About 42% of trash remains bottles and cans.
The experience of managing 2 types of trash trap brought us great insight. Nash Run Trash Trap is a screen type trap that captures both floatable and non-floatable trash. River Terrace Trash Trap is a boom type trash trap that collects basically ONLY floatable trash. It is obvious that the boom type trap does not capture non-floatable trash pieces. Thus, AWS used Nash Run Trash Trap data to figure out how much non-floatable trash is escaping from the boom type trap. AWS found that approximately 70% pieces of trash are not floatable. This means that while the boom type trap, River Terrace Trash Trap, is very important to beautify the Anacostia River, approximately 70% pieces of non-floatable trash just flow through underneath the trap.
We also found that the maintenance of the screen type trap, Nash Run Trash Trap, is laborious and it is not practical to install screen type traps across the watershed. Therefore, AWS uses the data from the traps to advocate for a better future: No one discards trash in our watershed and the environment.
Get Involved
It takes the support of many volunteers to help AWS maintain the trash trap. Look at our calendar of events to see when the next clean up of the Nash Run Trash Trap is for an opportunity to help clean the river alongside our AWS staff!
