I want to thank Chairwoman Johnson and Ranking Member Boozman for holding this hearing on: the Impact of Green Infrastructure and Low Impact Development on The Nation's Water Quality, Economy, and Communities. Water and its associated infrastructure play a vital role in maintaining our nation's economic, environmental, and community health. Yet, in terms of both investment and the adoption of new technologies, water infrastructure is an area that has been sorely neglected over the past decade. As a result, and especially with regard to stormwater, we stand on the precipice of retreating from many of the water quality gains we made in the 1970s and 1980s.
An inability or unwillingness to invest in an aging national infrastructure has left our wastewater systems stressed and broken. Similarly, a continual reliance on inefficient, and potentially outdated, technologies and operational approaches has hampered the ability of our communities to meet expanding water quality challenges in a more cost-effective and environmentally sensitive manner.
A promising way forward is through the adoption of green infrastructure, or low impact development, approaches and technologies. These approaches turn the whole notion of stormwater mitigation on its head. Instead of assuming that the volume of stormwater is fixed, and thereby creating engineered solutions, green infrastructure approaches use natural processes to decrease the volume of stormwater that even the stormwater conveyance system in the first place. If less stormwater enters the system, municipalities will be able to construct smaller conveyances to contain stormwater discharges. This means less financial expenditures for communities and jobs that can be completed more quickly.
Among the continuing water quality and water infrastructure issues the nation faces are those caused by Combined Sewer Overflows (CSO's), and stormwater discharges. The continued direct discharge of untreated sewage and stormwater into our nation's waters strikes at the very heart of the modern Clean Water Act: protecting our rivers, lakes, and streams from discharges of pollutants. Over 740 communities, most located in New England, around the Great Lakes, along the Ohio River, and in the Pacific Northwest, use combined sewers. As a result, pathogens and toxins continue to impair our waters, unchecked. Urban runoff, transported through stormwater systems, is also a major source of water quality impairments. This runoff not only carries toxics and sediment from roads, but the flow rates and channelization that occurs can cause major damage to the streams along which outfalls are placed.
The traditional manner by which many CSO communities have attempted to reduce CSO events is by reengineering their sewer and stormwater systems. Some cities have chosen to separate their combined sewer lines. Instead of running both sewage and stormwater in the same line, they are separated into two distinct pipes. While this system, known as a separated stormwater sewer system, has the advantage that it does not result in the discharge of raw sewage into rivers and streams, it has the distinct disadvantage of discharging all stormwater in an untreated manner. This means that all pollutants that are picked up by stormwater from city streets (chemicals, metals, sediment, oil, grease) will all enter local waters untreated.
Other municipalities are choosing to deal with their CSO discharges by building very large, deep tunnels. These tunnels are designed to temporarily hold billions of gallons of stormwater and sewage during wet weather events -- before being released into the wastewater facility to be treated. This approach has the advantage of treating all forms of wastewater in the conveyance system.
Both of these traditional, or "grey,' infrastructure approaches can provide remedies for damaging CSO discharges. However, they are very cost intensive, and can be very long-term projects. For example, in Chicago, the project construction lifespan of the city's deep tunnel will be over 40 years by the time it is completed in 2019. It is expected to cost the city $3.4 billion. Portland, Oregon's tunnel is expected to be completed in 2011, and will have taken 20 years to complete, at a price-tag of $1.4 billion. In this time of financial distress and economic uncertainty, municipalities are hard-pressed to dedicate their precious fiscal resources to these types of very large scale projects.
Stormwater may be an issue, however, that we cannot dig our way out using traditional tools and infrastructure approaches. Population dynamics in the United States are resulting in more of the population entering urban and suburban areas. As these regions grow, the amount of impervious surface will increase. As a result, the volumes of stormwater will intensify. This is especially true in areas in which there is more urban sprawl. As a result, the total area of impervious surface -- and therefore stormwater -- may increase at a faster rate than that of the national population. This will place increasing costs, for stormwater control, on municipal governments.
In addition, we can expect some regions of the country to have more frequent and more intense rainfall as a result of climate change. These communities will be under increasing stress -- financial and environmental -- in dealing with stormwater in the years to come. As a result, the traditional approach of developing more traditional infrastructure to deal with stormwater may not be the most cost- or environmentally-effective solution.
Green infrastructure, or low impact development, provides an alternative solution. Central to all green infrastructure technologies and approaches is the use of the natural environment to manage stormwater by capturing and retaining water, infiltrating runoff, allowing for evapotranpiration, and trapping and filtering constituent pollutants. Examples of these technologies or approaches include: green roofs; downspout disconnection programs; urban tree planting; adding green space; permeable pavements; and curb cut-outs. Green infrastructure approaches can also yield additional ancillary benefits including: the reduction of air pollution and urban heat island effects, the insulation of buildings in both cold and warm weather, and adding to the visual aesthetics of a city. While the installation of green infrastructure for stormwater control, especially in already-developed areas, can be expensive, the costs-savings, as a result of these ancillary benefits, can make the incorporation of these technologies and approaches a worthwhile endeavor for many communities.
Today's hearing will explore the utility and impacts of green infrastructure on water quality, State and municipal finances, and communities. These new approaches provide an intriguing way forward to negotiating the rapids of stormwater impairment that lie increasingly ahead. I look forward to hearing from the witnesses.