Columbia University Suggests Guards on NYC Streets Reduces Pollution in City’s Sewer System
Colombia University researchers have released findings from a new study of guards placed around trees in some New York City neighborhoods. The guards protect the trees and soil around them, and people often walk on the soil or let their animals go to the bathroom on the soil.
Guards were put in place to stop these occurrences, keeping animals and people away from the trees on the city streets.

photo/ Jo Wiggijo via pixabay
Allowing the trees to have some space is now found to provide even more benefits. The guards protect the soil, which is better able to absorb the stormwater. The result is a sewer system that is eased, relieving some of the burden of dealing with stormwater.
The permeability of the soil around the tree is increased, and provides a higher rate of water filtration.
Morningside Heights was the focus of the study, which meant to find out how fast water infiltrates the soil around trees – with and without guards.
Guarded trees have a six times faster absorption rate compared to non-guarded trees. Heavy storms have caused many of the city’s sewer systems to become overworked. The result of an overworked sewer system means that raw sewage and any remaining water will flow into nearby rivers.
Sewers will not overflow at such a high rate when trees are able to absorb water faster.
Outdated sewer systems and infrastructure are unable to handle the high rate of water flow as storms intensify in the region. Pipe corrosion and blockages are to blame for much of these issues.
“Pipe corrosion is fastened by factors such as; the type of material the pipe is made of, the liquid flowing through the pipe, as well as if the pipe is in the wall or ground. Iron lasts for about 15 to 20 years hence you will be required to change these pipes. Minerals in the water flowing through the pipes also increases pipe deterioration or corrosion. Most of the sewer line pipes have corroded therefore they have collapsed restricting proper flow of sewage,” explains NU Flow St. Louis.
There are around 680,000 trees on city streets in New York, and every year, there is some 1 billion gallons of stormwater that the trees intercept. The intercepting saves to city $10 million annually, yet with only 14% of the trees having protective guards, there is significant room for improvement. City streets can manage six times the rate of absorption that they do today with a guard.
Author: Jacob Maslow