“There are communities across the country that are now looking for efficient and effective ways to reduce stormwater pollution, minimize combined sewer overflows, and ensure that there will be safe and clean water resources for the future that are stymied due to lack of data, lack of modeling tools, lack of familiarity with these approaches by regulators and the public, and other roadblocks,” the cover letter by NACWA and NRDC stated. “We urge you to act now to remove those roadblocks and to commit both staff and financial resources to developing a program that would assist communities in analyzing and employing these approaches.”
“Green infrastructure” refers to the use of soil and vegetation in a community's wastewater and stormwater infrastructure to reduce the amount of water that enters the sewer and stormwater system. Green infrastructure can include green roofs, trees and tree boxes, rain gardens, vegetated swales, pocket wetlands, infiltration planters, and a variety of other vegetative methods to absorb rain water and prevent excess runoff. Green infrastructure can be used in lieu of or in conjunction with traditional 'hard infrastructure' like pipes, pumps, and storage tunnels.
The Statement outlines support for, among other things:
- The use of green infrastructure by cities and utilities as an effective and feasible means of reducing stormwater pollution and sewer overflows;
- The development of models to better quantify the stormwater detention, retention, and filtration potential of green infrastructure, and to better identify opportunities to successfully use green infrastructure for combined sewer, separate sewer, and stormwater programs
- The measurement of economic and environmental benefits realized from the use of green infrastructure in sewer systems and quantification of its life-cycle costs; and
- The elimination of barriers to incorporating green infrastructure in stormwater and sewer system programs.
The Statement also outlines the potential benefits of green infrastructure, including:
- Cleaner water — vegetation and green space reduce the amount of stormwater runoff and overflows from combined sewer systems;
- Cleaner Air — trees and vegetation improve air quality by filtering many airborne pollutants and can help reduce the amount of respiratory illness
- Increased energy efficiency — green space helps lower ambient air temperatures and, when incorporated on and around buildings, helps shade and insulate buildings from wide temperature swings, decreasing the energy needed for heating and cooling.
- Cost savings — green infrastructure may save capital costs associated with large hard infrastructure projects by reducing the overall amount of stormwater entering stormwater and sewer systems, thereby reducing the need for large hard infrastructure projects.