New York City residents produce more than 1.3 billion gallons of wastewater every day. As part of his PlaNYC, Mayor Bloomberg announced a new green infrastructure plan to reduce sewage overflow after heavy rains like the storms we’ve been experiencing in the past few week. You saw the effects in my post about the Gowanus Canal.
Here’s how WaterWire describes it:
Here’s a quick reminder of what stormwater runoff is: During a rainstorm, water falls on the city’s impermeable surfaces — roads, sidewalks, parking lots — and runs off, sluicing into gutters, flowing along to storm drains and picking up garbage, dirt and oil on the way. Stormwater and wastewater are carried in the same underground pipes, so waste treatment plants fill up faster during a storm. When the plants hit capacity, the noxious mix of polluted runoff and untreated sewage is released directly into waterways.
The Dept. of Environmental Protection is going pretty hi-tech with this: part of the plan is to replace some impermeable concrete surfaces with more porous pavement to absorb the rainwater. It’s also going more down to earth by planting more vegetation on roofs to absorb the rain before it reaches the gutters — “green” infrastructure as opposed to the traditional holding tanks and tunnels systems, known as “grey” infrastructure. They even want to use old-fashioned rain barrels in some neighborhoods, along with tree pits and streetside swales (ditches beside roadways).