Climate change is causing an increase in flooding, rising sea levels, and new weather patterns. These changes have a massive negative impact on older urban cities. In an urban environment, flooding is particularly an issue, especially if the sewer system is a Combined Sewer Outfall. Combined Sewer Outfalls, or CSOs, are outdated sewer systems that easily become overwhelmed during rain events. During dry conditions, sewage and rainwater make their way to the water treatment plant normally. However, when the system reaches capacity, especially when it rains, the sewer can only carry so much runoff and waste to the water treatment plant. The sewer will then fill up with excess sewage and storm water. This waste is then dumped untreated into the closest water body. CSOs contribute to flooded basements, homes, and streets. Children are often seen playing in contaminated water. This is an environmental justice issue for residents and families living in Camden.
So, what is the solution? Ultimately, the CSO needs to be completely replaced, and plans are underway for pipe clean outs and updates for Camden’s sewer system. In the meantime, planting trees is an effective way to combat storm water runoff, water pollution, and reducing the severity of flooding and contamination from an overworked CSO system. One way that trees contribute to cleaning up the environment is by de-paving and removing impervious surfaces. By breaking up the sidewalk and reducing the amount of concrete area, rainwater will have a place to go beyond down the nearest storm drain. Rain will infiltrate the ground, where filtration will happen naturally.
Trees further contribute to reducing storm water pollution and flooding by capturing and intercepting runoff. Trees are water magnets. A large growing tree, such as an oak, will require gallons and gallons of water to survive. When it rains, the water makes its way to the tree pit. Trees absorb moisture through their roots. The roots then act like filters, processing and breaking down pollutants in the storm water into a less harmful form. The water that is not absorbed by the tree directly will filter into the soil and recharge the groundwater. The tree’s leaves will also capture and filter out air pollutants in a similar way to how roots will process storm water runoff.
The NJ Tree Foundation had the opportunity to dream big while designing enhanced storm water tree pits for the 4th & Washington Park project. The 4th & Washington Street park in the Lanning Square West neighborhood of Camden had recently been renovated and sported large sidewalks. The park had some larger trees removed, making the sidewalks very hot in the summer. The NJ Tree Foundation worked to create massive tree pits that could support large shade trees and capture gallons of excess storm water during a rain event. Together, the nine tree pits removed a whopping total 704 square feet of sidewalk! Our contractors installed piping to increase aeration between the soil and gravel layers in the tree pit. Small shrubs and flowers were added to absorb more rainwater and to fill in the large tree pits with vegetation. On October 24th, 2020, volunteers from all over came to plant the trees and learn about the project. The trees selected will help to shade, beautify and capture polluted rainwater for years to come. They will also reduce the urban heat island effect by shading the sidewalk and cooling down temperatures under their canopy.
The NJ Tree Foundation uses i-Tree Design, a free software program that calculates the long term benefit of trees. To gauge the impact of this project, the NJ Tree Foundation submitted all of the tree species planted at this site: Dogwood, Blackgum/Black Tupelo, LittleLeaf Linden, Tulip poplar, Crepe myrtle, and Trident maple-and placed them in the program where they were planted. It is estimated that over the next two decades, the trees will together intercept 129,555 gallons of rain water and will process 27,298 gallons of storm water. That is hundreds of gallons of polluted storm water that will not end up in local rivers, lakes, and streams. The trees also help to remove particulate matter from the air: over the next 20 years, the trees will remove a combined total of 80 pounds of air pollution such as ozone, carbon dioxide, nitrogen dioxide, and more.
Lastly, the 4th & Washington Park sits only a few blocks from the Circuit Trail, which is an 800-mile network of hiking and biking trails that congregate in Camden and cross the Delaware River into Philadelphia. The NJ Tree Foundation is proud to build these large enhanced tree pits #onthecircuit and all around Camden. As the trees grow, they will continue to purify the air, capture storm water runoff, and combat climate change.