By: Wesley Holmes
APUS’ new Academic Center is being developed with a number of innovative technologies designed to reduce environmental impact and energy consumption. One of the technologies is an innovative new elevator operating system that promises to achieve significant energy savings and avoid the environmental threats of more traditional elevator systems.

Elevator from Kudda on Vimeo.

In the past, low rise buildings of only two to six stories utilized hydraulic lift systems. Hydraulic elevators function as a closed pressurized system, utilizing hundreds of gallons of oil to drive a piston which moves the elevator. The system has three basic components; A tank (the fluid reservoir), a pump powered by an electric motor and a valve between the cylinder and the reservoir. The pump forces fluid from the tank into a pipe leading to the cylinder. When the valve is opened, the pressurized fluid will take the path of least resistance and return to the fluid reservoir. But when the valve is closed, the pressurized fluid has nowhere to go except into the cylinder. As the fluid collects in the cylinder, it pushes the piston up, lifting the elevator car. According to relevant literature and product reviews, these systems suffer from some major disadvantages. Those being the size and space requirements of the equipment as well as the comparative inefficiency and potential environmental threat of hydraulic oil based technology.

Image provided by howstuffworks.com

As you can see in the diagram, the piston pushing the elevator is set inside a cylinder. The cylinder has to be a little bit longer than the piston, of course, since the piston needs to be able to collapse all the way when the car is at the bottom floor.  More stories mean a longer cylinder. The problem is that the cylinder structure must be buried below the bottom elevator stop. Meaning you have dig under the building slab to set in the cylinder. As systems age, hydraulic elevators can slowly leak oil from the cylinder into the earth, decreasing efficiency and contaminating the surrounding soil. This would be a particular issue for the Academic Center given that the buildings’ foundation is designed to cap the Brownfield contaminants underneath. Setting in a leaking cylinder would defeat the purpose of this cap.

The space requirements of a hydraulic elevator system are substantial. In traditional systems an additional room is needed adjacent to the elevator shaft to house the pumping equipment. Given that the Academic Center will have no basement, an elevator control room would take up substantial space on the first floor. Including a control room also involves a number of additional design and code specifications which translates to increased construction and design costs for the building owner. These costs can be compounded over the years given that hydraulic elevators are fairly inefficient. It takes a lot of energy to raise an elevator car several stories, and in a standard hydraulic elevator, there is no way to store this energy. The potential energy only works to push the fluid back into the reservoir. To raise the elevator car again, the hydraulic system has to generate the energy all over again.

Image Provided by KONE.com

To address the issues presented by traditional hydraulic systems, the Academic Center will utilize a new electric traction elevator system developed by KONE. KONE is one of the world’s leading elevator and escalator companies and the first in its industry to join the U.S. Green Building Council. At the USGBC Green Building Expo in Chicago in 2007, Vance Tang, President of KONE announced that they would discontinue manufacturing hydraulic elevators and introduced their new environmentally friendly EcoSpace Machine Room-Less (MRL) elevator technology. Machine room-less elevators are designed so that most of the components fit within the shaft containing the elevator car; and a small cabinet houses the elevator computer. In addition to the space savings, the traction rope is configured for force multiplication in a complex pulley system. In this configuration, the traction motor moves more rope per distance traveled, but works half as hard due to force multiplication factors of the pulley system.

KONE engineers find that these systems are up to 60 percent more energy efficient than traditional hydraulic elevators, potentially saving thousands of kilowatt hours per year for single elevators. KONE has seen through energy comparisons that the savings from a wattage and actual dollar value can be significant with a MRL elevator versus a hydraulic system. These energy comparisons have been conducted on several existing facilities to measure the “before” and “after” results of these two types of systems. For instance, at the Independent Bank facility in McKinney, Texas the results of replacing an existing in-​​ground hydraulic with a KONE EcoSpace elevator system resulted in the customer reducing 11,907 KWh and cost savings of $1,071 annually. These findings suggest a significant return on APUS’ investment in new elevator technology.

Useful Links

KONE elevator video

By: Wesley Holmes

One of the principle concepts of sustainable development is to avoid devouring unspoiled landscape and find ways to make our existing infrastructure more efficient and affordable. To avoid the continued decline of natural habitat and ecosystem services it is becoming increasingly necessary to take a fresh look at the homes we have already built and try to make them more affordable and attractive to first time home buyers. A new report, issued by the Joint Center for Housing Studies of Harvard University, finds that the weak economy coupled with an increase in government programs to support home renovation and first time homebuyers have made sustainable re-development the most promising growth sector in the housing market.

The State of the Nations Housing Report provides a periodic assessment of the nation’s housing outlook and summarizes important trends in the economics and demographics of housing. Predictably, this years report is short on good news. Fewer homes were started in 2009 than in any year since World War II. Census Bureau estimates show that construction permits totaled just 583,000 in 2009, compared with 2.16 million at the 2005 peak and an annual average of 1.32 million in the 1990s. This is the first time since 1959, when records began being kept, that annual permits have numbered less than 900,000. One of the most interesting key facts in the report is that while new home sales were down by 23-percent, the sale of existing homes in 2009 climbed five-percent. Much of the growth in existing home sales is credited to declining real estate prices, along with government tax credits marketed to first-time homebuyers. The report notes that controversial bailout programs helped spark a turnaround and drove all of the increase in existing home sales in 2009.

Experts note that the outlook for the housing market will continue to be rather bleak until employment and income, the leading indicators of housing development, begin to rise. One of the chief impediments to home ownership is the issue of affordability. All told, 40.3 million households spent more than 30 percent of their incomes on housing in 2008, while 18.6 million of these households spent more than half—up from 13.8 million in 2001. After holding steady at 12 percent in both 1980 and 2000, the share of “severely burdened” households (those spending more than half their incomes on housing) jumped by a third, to 16 percent, in 2008. More than half of the 4.5 million low-income single-parent households spent 60 percent or more of their incomes on housing in 2008.  Lower income households with children who dedicated more than half their income to housing had less than $600 per month left for all other necessities. Similarly burdened elderly and single-person households had even less (under $500) left over after housing expenses.

While the housing market and new home development face a long road to recovery, experts do see opportunity to make significant gains in energy efficiency for municipalities and reduction of utilities expenditure for homeowners. In a recent press release, Casius Pealer, director of affordable housing policy for the U.S. Green Building Council, noted that “As existing home sales begin to rise, there is a great opportunity to bring the energy and water efficiency aspects of these homes up to today’s standards,” The Housing Report found that if all pre-2000 homes were brought up to the same efficiency as post-2000 homes in their regions, residential energy consumption would fall by 22.5 percent! Indeed, the only sector to show growth in the 2010 Housing Report is in energy efficiency home renovation. In 2009, the American Recovery and Reinvestment Act (ARRA) extended energy efficiency tax credits for homeowners and funded low-income home weatherization programs. The share of professional remodelers reporting that they had worked on projects linked to the energy efficiency tax credits increased from 39 percent in 2009 to 53 percent in early 2010. Mohsen Mostafavi, Dean of the Harvard University Graduate School of Design noted that “Today’s homeowner has the ability to significantly reduce home energy costs through environmentally-conscious building materials and design approaches”.

As home prices move consistently higher, the Housing Report predicts that some of the equity that owners lost over the last decade will be restored. But rising prices will also put additional strain on the already large number of households facing affordability challenges. One of the reports seminal conclusions is that tackling affordability issues while leveraging the potential of housing to anchor neighborhood revitalization and achieve energy savings will need to be national priorities in the decade ahead. Contrasting with oft heard calls for an end to federal domestic spending, the report calls for a continuation and expansion of policy implements like those found in the ARRA that will encourage efficient home and community design as a means to drive down housing costs and make homeownership more affordable. Longer-term federal commitments include HUD’s new Sustainable Communities Initiative, to encourage more energy-efficient and transit-friendly development patterns on a local level. Additionally, homeowners and builders alike continue to make homes more energy efficient, led by regional certification programs such as the USGBC’s LEED for Homes and LEED for Neighborhood Development programs, both of which offer credits for smart location and linkages and location efficiency. At stake are potentially large savings in the energy consumed to heat and cool homes, as well as in the number of vehicle miles traveled and related carbon emissions.

Projects like the APUS Academic Center are at the forefront of this growing development paradigm. The success of our project in Charles Town will serve as a guiding example of how we can utilize sustainable development practices to bring new vitality and much needed economic opportunity to communities across the country.  Simultaneously lowering the cost of property ownership through increases in efficiency and sensible project siting.

Links of Interest

HUD-DOT-EPA Interagency Partnership for Sustainable Communities

Renewable Energy World Magazine; May/June 2010-Volume 13, Issue 3

In the most recent issue of Renewable Energy World International Magazine (May/June 2010), an article was published on the power of small and midsize local governments to drive sustainable development in their communities. The article was written by Ralph Sims, a Professor of Sustainable Energy at Massey University in Palmerston North, New Zealand. The article is derived from a similar paper Sims produced on the subject for the International Energy Agency (IEA) in 2009. The paper details the variety of methods and legal authorities local governments can bring to bear to drive sustainable developments in their communities and highlights the achievements of some small communities.

The IEA reports that more than 50% of the world’s population currently resides in urban environments and this proportion will continue to grow over the next few decades. According to the IEA, urban areas produce around 71% of global, energy-related, CO₂ emissions and are on track to rise to 76% by 2030. With this kind of consumption at the community level, it is important for local governments to take a more proactive role in guiding community development and reducing environmental impact. Sims research finds that local governments have significant power to influence the energy choices of their citizens. They administer and regulate water supply, waste collection, public transport, and infrastructure. They own buildings, land, waste treatment facilities and vehicle fleets and they have close proximity to citizens and businesses.

Successful policies instigated by large and small city councils and local municipalities from around the world have resulted in the significant advancement of renewable energy projects. For example, the borough of Merton in London, England, introduced a regulation that all new buildings would have to meet at least 10% of their total energy demand from renewable energy technologies that are integrated into the building structure. This regulation has now been copied by many other local authorities throughout the UK. Another ordinance, introduced in Barcelona in 2000, required that solar water heaters be installed on all new and retrofitted buildings. This ordinance, with various modifications, has now been replicated throughout Spain as a national directive. Projects such as these demonstrate how leaders and officials of local governments are getting more involved in climate change policy-making by strategic planning; formulating, approving and implementing policies; evaluating their effectiveness; and disseminating successful actions for replication elsewhere.

Sims article also offers a variety of suggestions on how local governments can affect positive change in their community. Given that a municipality owns and operates a range of buildings and facilities it can do what it wishes in terms of their management and energy supply, this offers an opportunity to lead by example. The local government also collects, treats and disposes of solid and liquid wastes, the control and treatment of wastes is a major component of sustainable development. As a property owner and management firm, a city council can take a sustainable leadership role by introducing, designing and developing renewable energy projects and systems for their own activities. The city thereby becomes a role model for local businesses and citizens to follow where appropriate, as well as for other similar size municipalities to emulate.

For municipalities looking to stimulate actions outside of their owned properties, a local government, to varying degrees, can employ a variety of governing mechanisms to educate, encourage, or by regulation force the adoption of healthier and more efficient technologies and practices. For instance, larger local governments are often in a position to provide governance by provision; in which various forms of financial incentives are offered to encourage renewable energy project deployment. Local governments also often have the power to employ governance by authority; in which it can thereby determine and introduce regulations set to meet certain objectives. The target might be fairly broad, such as reducing overall greenhouse gas emissions, or be more specific, such as a mandate that all local buses and taxis will be run on a specified blend of biofuels, or that all new building construction will have to include the installation of a ground source heat pump. Finally, most local municipalities are usually in a good position to undertake governance through enabling; by providing education, training, advice, research and information services for its local businesses and citizens. In many cases it has been shown that both regulations and financial incentives can be more successful when undertaken in parallel with an information and educational campaign.

Various types of municipalities can exercise their functions by using a range of specific policy instruments. Sims research notes that successful policies are rarely implemented in isolation and it is more typical to develop and introduce a suite of complementary policies simultaneously. The local approach can help demonstrate what is possible, at what costs and who the winners and losers might be. This localized form of sustainable policy development serves as a proving ground for national policies. Sims notes that “Social experimentation relating to renewable energy deployment can be undertaken at the local level and, where successful, adopted nationally”. In his summation, Sims calls for national governments to enable action at the local government level in order to fully integrate renewable energy and climate considerations into urban development strategies.

By: Wesley Holmes

Wellesley Parking Lot (Image Courtesy of Time Magazine)

This morning I found some time to sit around drinking coffee and reading this weeks’ (May 31) Time Magazine , a rare and pleasant occurrence on Tuesday. I came across an interesting article in the Life Section titled Extreme Makeover: Parking Edition. This brief piece, by Lisa Davis, details the re-thinking of American parking space. The article highlights a number projects going on around the country to maximize the utility of thousands of acres of paved parking areas. Projects include a variety of clever start-ups, such as building over the top of parking areas to create mixed use and residential building space, as well as a San Diego based project covering expansive garage roofs with solar panels that provide enough energy for 68 homes. Some projects are more lo-tech and lo-cost efforts to turn expanses of asphalt into green space. Pictures from the article illustrate how Wellesley College, over the course of a seven year clean up project, turned a 175 space parking area covering a toxic brownfield into a community park. The parks wetland features now help to manage stormwater runoff.

Wellesley's new park (Image courtesy of Time Magazine)

The article also mentioned a really cool urban planning competition that I want to pass along to APUS students and faculty. Currently, there is an open call to architects, urban designers, planners, students, visionaries and everyone else interested in re-shaping Long Island suburbs. In other words, you don’t have to an engineer; you just have to have a good idea. It’s called the “Build a Better Burb” competition and its creators, a research non-profit called the Long Island Index, are looking for “bold design proposals for retrofitting underutilized asphalt in suburban downtowns into innovative and surprising new uses, forms and urbanisms”. The project invites visionaries of whatever stripe to offer design and redevelopment plans for a number of large parking areas throughout the “first suburbs” on Long Island. The parcels of land add up to an amazing 8,300 acres of land that could be put to better use. Submittals for the project are due by June, 21^st, but for those most outstanding ideas the judges will award a guaranteed first prize of $10,000 and $10,000 in additional prizes, to be announced in September 2010. In addition there will be a $2,500 prize awarded to the top project submitted by a student currently enrolled in an undergraduate or graduate program.

This project presents an opportunity to re-think how our communities are designed and explore ways pre-developed land can be re-utilized to reduce our consumption of unspoiled natural land. In doing so, it embodies the principal theme of next months (June 15-17) 2010 Green Remediation Conference. The conference is being co-hosted by the Environmental Institute, the University of Massachusetts Amherst, and the U.S. EPA Office of Superfund Remediation and Technology Innovation. The conference, to be held at Amherst, will provide a forum for scientists, regulators, environmental engineers, sustainability managers, educators, and other stakeholders to interact and share new knowledge on how green approaches can be applied to site cleanup and sustainable reuse. Apus-green-building.com is happy to announce that Environmental Studies Program Director, Dr. Carol Pollio and I will be presenting the APUS Academic Center project as a case study on brownfield revitalization through sustainable development. Our project will be presented as part of day long symposium of sustainable development projects and technologies. As President Boston noted at the outset, one of the goals of this project is to set an example for others in the community. Community revitalization and environmentally conscious development are a hallmark of the growth of APUS. The conference in Amherst provides an ideal venue to showcase the economic viability and sound business strategy of the APUS approach.

BP Deepwater Horizon April. 20 (Image provided by Reuters)

Around the world, corporations, particularly publicly traded corporations, are gradually beginning to realize that environmental accountability and social responsibility play as large a role in attracting investment as any other economic indicator. The relationship between investor confidence and companies’ environmental impact was recently illustrated by the catastrophic failure of BP’s gulf coast oil rig, Deepwater Horizon. The disastrous failure of the rigs safety features has already taken a devastating toll on the ecology of the Gulf Coast, and is likely to have harmful ramifications long into the future. The magnitude of the Deepwater Horizon disaster and the immediate and long term costs it implies for BP seems to be sinking in with BP investors as well. According to the New York Times, BP’s stock has plunged more than 13% since the incident began on April 20^th. The company which

(marketwatch.com) BP Stock drop on April, 21

operated the rig, Transocean, has seen stock prices fall by more than 14%.

In 1989 another major environmental disaster shook public confidence in corporate America—the Exxon-Valdez oil spill. 10.8 million gallons of oil poured into Alaska’s Prince William Sound, devastating one of the world’s most pristine habitats. Suddenly, the environmental cost of doing business became painfully clear. In response to the Exxon-Valdez incident, a group of investors established Ceres.  Ceres, pronounced “Series”, is a national network of investors, environmental organizations and other public interest groups working with companies and investors to address sustainability challenges. The US based Ceres now manages the Investor Network on Climate Risk (INCR), comprised of more than 90 institutional investors who collectively manage nearly $10 trillion in assets. In a very timely coincidence, on March 18, just weeks before the rig failure, Ceres and other institutional investors released new climate disclosure guidelines for the oil and gas sector. Identifying significant future investment value at risk, the investors said that levels of transparency from oil and gas companies are now needed to reflect the shift in regulation internationally because of climate change. Mindy Lubber, Ceres President and INCR Director said “Companies in the oil and gas sector face significant climate risks and should be assessing, managing and disclosing the impact of those risks on their businesses and supply chains. Investors want to know, for example, what return they will get from their portfolio companies that are pumping tens of billions of dollars into carbon-intensive Canadian oil sands extraction when low carbon fuel standards take hold.”

This need for full disclosure of environmental factors is also gaining acceptance at the Securities and Exchange Commission (SEC). In early 2010 the SEC issued guidance on how publicly traded companies should report on climate change-related risks and opportunities. The guidelines do not create new legal requirements, but they do say companies should account for the material impacts of climate change on their business, such as how it could affect their operations, or demand for their products or services. In a recent publication of Sustainable Industries, Sara Stroud wrote an excellent report on the state of corporate social responsibility (CSR) efforts. As of spring 2010, investors had filed almost 100 climate change-related shareholder resolutions with U.S. and Canadian companies—a 40-percent increase over the total number filed in 2009, according to Ceres.

While the BP oil spill and Exxon-Valdez incidents represent extreme examples of potential environmental costs, it is important for all companies to examine their impact on the environment and examine the potential costs of mitigation and cleanup. Such preparation is becoming increasingly important as climate change and pollution control come under increasing regulation. Clark McKinley, a spokesman for California Public Employees’ Retirement Systems (CalPERS) notes that the heightened pressure from investors around CSR reporting largely boils down to managing risks; Risks which include risks to assets, infrastructure and operations, as well as legal, regulatory and reputational risks. “We believe the market will reward investors who see the climate change challenge as opportunity, and investors and companies that are slow to act will find themselves years behind the curve,” McKinley wrote in an e-mail to Stroud. “Those that focus on innovation as the world shifts to a low-carbon economy will go a long way in ensuring their viability and competitiveness.”  This is business paradigm that APUS has embraced for many years. As an active proponent of the Campus Sustainability Movement, APUS has committed much of its resources to adapting to the emerging clean energy economy.  The development of the new Academic Center is just another of the community oriented growth projects APUS has initiated.  As research has shown and the recent Gulf spill tragedy has illustrated corporate social responsibility does play a decided role in attracting investment and reducing perceptions of risk. As APUS continues to invest in a sustainable growth,  investor perceptions of security and risk reduction are likely to grow along with it.

Useful Links

2010 Investor Summit on Climate Risk

US Chamber of Commerce Business Civic Leadership Program

Yale School of Management: Program on Social Enterprise

Harvard Corporate Social Responsibility Initiative

Links Page

By Wesley Holmes

As APUS has grown and expanded it has consistently embraced an environmentally conscious business model. The decision to achieve LEED Gold standards of performance for the new Academic Center is a continuation of this sustainable philosophy and representative of a collective movement among colleges and universities across North America to make our educational institutions more environmentally sound and economically sustainable. A quick Google Scholar search of “greening our academic institutions” reveals that the idea of colleges and universities taking a lead role in environmental sustainability emerged in the early 1990’s and has been steadily gaining in momentum over the past two decades. The growth of this movement has manifested in organizations such as the Association for the Advancement of Sustainability in Higher Education (AASHE) and organized institutional efforts such as the American College and University Presidents Climate Commitment (ACUPCC). These collective efforts have come to be known as the Campus Sustainability Movement.

The origins of this movement within academia are best articulated by Leith Sharp of the Harvard School of Public Health and founder of Harvard’s Office for Sustainability. According to Sharp, the Campus Sustainability Movement was born out of frustration with the clear disconnect between the environmental threats and ecologic principles expounded upon in the classroom that were being largely ignored in campus facility design and operation. For many students and faculty the idea of teaching sustainability without demonstrating it is highly problematic. Students and faculty alike wanted to take a more proactive role on their campuses and turn theory into practice. It has been suggested that this drive for ecologic stability on campuses largely mirrors growing desires for sustainability across the country. Advocates for campus sustainability initiatives note that the higher education sector serves as an ideal proving ground for sustainable technologies and practices. These sentiments have helped fuel a movement dedicated to transforming our educational institutions into living laboratories for the demonstration and practice of environmental sustainability.

Over the last decade the Campus Sustainability Movement has made significant strides. According to a National Wildlife Federation Campus Ecology Survey conducted in both 2001 and 2008, of the 1,068 schools surveyed in 2008, 65% had some form of written commitment to address environmental sustainability or stewardship (or at least had a plan in place to create one), compared to just 43% of the schools surveyed in 2001. In 2007, the American higher education sector had approximately 285 construction projects underway that had been certified under the United States Green Building Council’s (USGBC) Leadership in Energy and Environmental Design (LEED) program (USGBC, 2007). At the time, this accounted for about 10% of LEED projects nationally. According to AASHE, between mid-2007 and March 2009, over 620 presidents of colleges and universities in the United States endorsed the American College and University Presidents Climate Commitment (ACUPCC). One of these signatories was APUS President Wallace Boston. President Boston on joining the ACUPCC.

Since signing the Commitment, APUS has taken several significant steps toward reducing its overall carbon footprint and working toward achieving carbon neutrality in its operations.  Under President Boston’s guidance, APUS has implemented a Sustainability Committee which is tasked with managing the various aspects of the Commitment.  Comprised of employees from nearly every department within the online university, the Committee is dedicated to addressing various aspects of the school’s operations in order to achieve greater sustainability.  The school has implemented a recycling program in both its Charles Town, WV and Manassas, VA locations.  Additionally, the school’s admissions process is now completely paperless, leading to a more streamlined experience for students and staff as well as a more environmentally sound operation overall.  The school is currently working to implement systems to create a paperless accounts payables process as well.  In late 2009, the university installed an environmentally friendly porous paving system in its Charles Town, WV location.  The system prevents storm water runoff by providing a compacted layer of stone beneath the pavers which serves as a filter for water prior to its absorption into the ground.  Nearly all buildings in both APUS campus locations have been outfitted with occupancy sensors which have greatly increased energy efficiency.  Members of the school’s Sustainability Committee have recently launched a blog, http://apus-sustainability.com, which will serve as an outreach mechanism for sharing ideas related to sustainability in higher education, in general, as well as a means of documenting and sharing APUS’ experiences as it works toward achieving a more sustainable future.

Links and Citations

LEED Certified Projects Directory

National Wildlife Federation Campus Ecology Program

The College Sustainability Report Card

Sharp, L. 2009. Higher education: the quest for the sustainable campus. Sustainability: Science, Practice, & Policy 5(1):1-8. http://ejournal.nbii.org/archives/vol5iss1/editorial.sharp.html.

United States Green Building Council (USGBC). 2007. LEED Registered Projects. https://www.usgbc.org/ShowFile.aspx?DocumentID=2313. (March 19, 2010)

By: Wesley Holmes

SS Credit 6.1: Stormwater Design—Quantity Control

1 Point

Intent

To limit disruption of natural hydrology by reducing impervious cover, increasing on-site infiltration, reducing or eliminating pollution from stormwater runoff and eliminating contaminants.

Requirements

Case 1-Option 1. For sites with existing imperviousness 50% or less implement a stormwater management plan that prevents the post development peak discharge rate and quantity from exceeding the predevelopment peak discharge rate and quantity for the 1- and 2-year 24-hour design storms.

When land is altered for development, the way stormwater moves through the landscape is fundamentally altered. In an undeveloped landscape, trees, shrubs and other vegetation reduce stormwater runoff volumes through various processes. When rain falls to the ground the leaves of branches and shrubs catch or intercept the rain. This process, termed interception, lowers the total amount hitting the ground and reduces impact on topsoil. Transpiration is a more complex process where water captured in root systems is processed through the plant and released through leaves. In addition, the topography of an area usually will have natural depressions which collect water allowing evaporation. Ultimately these processes work to reduce the amount of water flowing through collecting streams and storm drains. According to a 2008 report issued by the National Research Council on Urban Stormwater Management in the United States in addition to entrainment of chemical and microbial contaminants as stormwater runs over roads, rooftops, and compacted land, stormwater discharge poses a physical hazard to aquatic habitats and stream function, owing to the increase in water velocity and volume that inevitably result on a watershed scale as many individually managed sources are combined.

When land is typically prepared for development it is graded, compacted and in many places paved. Grading removes the native soils and natural depression areas that once worked to retain rainfall and stormwater runoff on site. Compaction reduces the infiltration capacity of the underlying soils and increases the amount of rainfall that is converted to stormwater runoff. The addition of roads, parking lots, rooftops and other impervious surfaces work to further increase stormwater runoff volumes and flow. In the end, much of the rainfall that was once retained in the landscape is now converted to a flow of stormwater runoff. This increase in flow rates can have significant erosion impacts on receiving streams and riparian vegetation.

LEED Site Selection Credit 6.1 requires that the peak discharge rate and quantity of stormwater after development does not exceed the predevelopment peak discharge rate and quantity for the 1- and 2-year 24-hr design storm (Really heavy and lasting rain). Essentially this requires that the Academic Center development to maintain the rate and amount of runoff from the site. The runoff control is being achieved through a retention and treatment pond which will be covered in next weeks post on stormwater quality control.

External Links of Interest

EPA Urban Stormwater BMP Performance Tool

EPA National Menu of Stormwater Best Management Practices

Center for Watershed Protection