11/14/2011 08:33 am ET Updated Jan 14, 2012

New York's Exciting Experiment in Green Infrastructure

While the federal government's ideological conflicts have stalled many efforts to achieve environmental sustainability, here in New York the grownups running our state and city environmental agencies have managed to continue to make progress. Recently the state and city signed a draft agreement allowing the city to begin implementing its green infrastructure approach to reducing water pollution into the city's hundreds of miles of waterfront. Hopefully, the federal government will allow them to implement this agreement.

Water quality in the New York Harbor, the Long Island Sound and the Hudson and East Rivers has improved dramatically in recent decades thanks to the success of national, state and local-level policies and regulations. These days there is a wonderful new bike/jogging path that brings you right next to the Hudson River, something unimaginable before the river's clean-up. However, the problem of combined sewer overflow remains one of the most difficult water quality issues facing New York City. Combined sewer systems are typical of cities with old infrastructure: the sewage from your home is combined with sewage from street sewers before it is piped to the local sewage treatment plant. The problem is that if a large amount of rain suddenly sends a high volume of water into street sewers, it can overwhelm treatment plants and push raw sewage into local waterways before it is treated.

The traditional approach to dealing with the combined sewer overflow problem is to build tanks and other facilities to hold storm water during storms and then release it into the sewers once the storm has ended. In September 2010, New York City released its landmark Green Infrastructure Plan, which made use of vegetation, porous pavements and streets, green and blue roofs and even rain barrels to augment traditional investment in "gray infrastructure." These low-cost techniques reduce the impact of storms on the city's water treatment plants. Green infrastructure can quickly reduce the flow of wastewater to treatment plants since it takes much less time to plant greenery or put out rain barrels than to site, design, build and operate a holding tank.

The goal of New York's innovative green infrastructure plan is to reduce sewage overflows into NYC waterways by 40 percent by 2030. The city's 2010 plan estimates costs that are $1.5 billion dollars less than the traditional gray strategy. Green infrastructure projects provide multiple benefits for the city including cleaner air, reduced urban heat island effect, improved energy efficiency, and enhanced quality of life through increased access to green space.

The recent New York State and City agreement includes many of the innovations proposed in the city's 2010 Green Infrastructure Plan. The agreement modified the city's existing method of improving harbor water quality by calling for investment of approximately $187 million in green infrastructure projects by 2015. It will utilize green infrastructure to reduce storm water from entering the system from over 10 percent of available impervious surfaces in combined sewer drainage areas by 2030. The agreement calls for a total of $2.4 billion public and private investment over the next 20 years including $1.6 billion in traditional gray infrastructure projects.

The agreement also promotes flexibility and accountability. The state and city have institutionalized a form of adaptive management that builds in milestones and performance measurement and allows for changes as data, technology and processes improve over time. The first milestone is scheduled for 2015, and according to the New York City Department of Environmental Protection:

If the city misses this milestone, it must submit a contingency plan to implement more green or gray infrastructure. If the city implements an approved contingency plan and still does not meet the milestones, it must pay a penalty...The draft agreement also requires DEP to establish detailed Long-Term Control Plans between 2013 and 2017 to effectively address any remaining concerns with CSOs.

The agreement between New York's two major environmental agencies places the city on the path to implement the vision presented in last year's green infrastructure plan. When the plan was released, I thought the chances of implementation were no better than 50-50. The agreement is an impressive accomplishment and I am particularly pleased to see the specific output metrics and timetables included in the draft to help ensure accountability going forward. The agreement recognizes that we are early in the process of learning how to implement green infrastructure projects and permits the flexibility needed to adapt as we learn more about this innovative approach to pollution control. The willingness to be open to such learning is important as we develop new and cost-effective methods of urban sustainability management.

The ability to learn from mistakes is rare in government these days as it seeks to spin the 24-7 news media and keep simplistic negative stories from gaining traction. This openness to learning is given operational meaning by the agreement's provision to defer making a decision to construct Combined Sewer Overflow tunnels for Newtown Creek and Flushing Bay until 2017. By then we will know much more about the effectiveness of these green techniques. Those tunnels are estimated to cost approximately $1 billion each, and if we could demonstrate that an ecosystems services approach could save most of these funds, it would be an exciting and important demonstration of the principles of green infrastructure.

The addition of green infrastructure to the city's Combined Sewer Overflow reduction strategy is evidence of the Bloomberg administration's increasingly sophisticated approach to maintaining and enhancing the city's environmental quality. It also reflects the cooperative relationship between the state DEC and city DEP in developing progressive sustainability action plans.

When I wrote about New York City's green infrastructure plan last year I concluded :

The Bloomberg administration has again demonstrated its ability to marry sound business and environmental principles. They have once again placed themselves at the forefront of the emerging field of sustainability management.Commissioner Cas Holloway and his team at the Department of Environmental Protection should be applauded for this extensive and cost-efficient plan.

We should now applaud State Department of Environmental Conservation Joseph Martens and New York City Department of Environmental Protection Commissioner Carter Strickland and their teams for negotiating this important agreement. With evidence of dysfunctional government all around us, it is heartening to see our local and state environmental agencies working together on a critical issue.