The current plan, also known as grey infrastructure, depends largely on large tunnels to reduce and control overflows going into the District’s Rivers. The tunnels, 13 miles long and larger than Metro tunnels, are constructed more than 100 feet below the ground (District of Columbia Water and Sewer Authority. (n.d.). Retrieved February 17, 2015, from http://www.dcwater.com/workzones/projects/first_street_tunnel/faqs.cfm). They are designed to capture CSO during heavy rains and discharge it to Blue Plains for treatment. There is currently a schedule and a 2025 deadline for construction of the tunnels and related CSO control facilities. When complete, it will reduce overflows by 98 percent (Anacostia only) – or more than 2 billion gallons of diluted sewage a year (Green Infrastructure Project. (n.d.). Retrieved February 17, 2015, from https://www.dcwater.com/education/pdfs/green_infrastructure_brochure.pdf).
While the CSS works well under dry weather, during rainstorms, the high-volume flow can exceed the capacity of the pipes in the system. In order to prevent sewer backups, the sewers are designed to overflow into the rivers during rain events causing water pollution problems due to bacteria, chemicals and debris.
DC Water and Hawkins are proposing the green infrastructure pilot program to explore whether a large-scale green solution can reduce overflows enough to make the next tunnels smaller or eliminate them altogether (Green Infrastructure Project. (n.d.). Retrieved February 17, 2015, from https://www.dcwater.com/education/pdfs/green_infrastructure_brochure.pdf).
Unlike the grey infrastructure, green infrastructure draws its inspiration from nature and is meant to capture precipitation where it falls and allow it to filter through or release more slowly and naturally. This practice will reduce the amount of wastewater and storm water going into the waste treatment plant. By doing so, it will increase the efficiency of the plant while reducing the amount of waste (trash, bacteria, heavy metals etc.) that is being dumped into the rivers during overflow.
According to Hawkins, green infrastructure will play an important role in the community. Washington residents play an important role in “greening” their community both environmentally and aesthetically (Hedges, T. (2013, August 7). DC Water Prefers Green Infrastructure, Despite Uncertainties. Retrieved February 17, 2015, from http://thefightback.org/2013/08/dc-water-prefers-green-infrastructure-despite-uncertainties/) . Social capital is the concept that individuals and the community benefit from individuals knowing their neighbors and having supportive social networks (Social capital. (n.d.). Retrieved February 17, 2015, from http://en.wikipedia.org/wiki/Social_capital). Plant life in urban areas encourages use of outdoor spaces and fosters more social interaction. These interactions generate support community cohesion by increasing a sense of well-being, concern for one’s neighbors and community in general. In addition, green infrastructure will also increase local jobs because of a growing need for employees with skills to install and…