A Sustainable Milestone

Nationals Park, located in the Near Southeast area of Washington, D.C., is America’s greenest ballpark, the first professional stadium in the United States to earn LEED Silver Certification. Situated on the banks of the Anacostia River--one of the most neglected natural resources in the region--the ballpark’s site dictated much of its sustainable design attributes to help minimize further pollution of the site and its surroundings.

The area is characterized by large public and subsidized housing complexes and relatively small portions of retail and commercial space. Parking near the ballpark is limited--not only to encourage the use of public transportation, but also to avoid the blight of surface parking, and to enable a more pedestrian-friendly neighborhood. As a planned anchor for millions of dollars of mixed-use development in the area, Nationals Park’s design incorporated sidewalks, open spaces, plazas and retail frontage.

The previous inhabitants were low-density warehouses, an asphalt plant with its by-products and light industrial businesses, as well as a trash-transfer station. The ballpark was enrolled in the District of Columbia’s Voluntary Clean-Up Program, and, as such, the site’s 18.76 acres are in better condition environmentally than before its development. Additionally, the ground-water and storm-water systems put in place by this project are expected to provide continuous environmental remediation for the lifespan of the facility.

“At the onset of the ballpark’s design, there were no green-certified sports facilities in the United States,” says Joe Spear, FAIA, Senior Principal at HOK Sport, the architecture firm that designed the ballpark. “And because most green-design rating systems are designed for offices and schools, we truly had no model to follow. It was an interesting design challenge, but by creating strong buy-in from all parties, we were able to create a one-of-a-kind green ballpark.”

Given the ballpark’s site near the river, the team’s main sustainable design strategies were to mitigate the construction process impact on the environment, to protect the natural resources, and to produce a facility that offered a measurable improvement in building performance.

To start the process, the sustainable team (the owner, user, contractor and design team) initially scored the building for a number of credits the facility could achieve, and then priced the credits prioritized by each stakeholder group to determine if these credits fit within the budget. This scorecard became the basis of implementation, which had to be reviewed and monitored through a number of parties to ensure that every team member was working toward the goal of a sustainable ballpark. During weekly progress review meetings with the stakeholder group, an update was given for each credit and where it stood in the documentation process. One of the biggest challenges was keeping the targeted credits within the budget and on track within a tight, fast-paced construction schedule.

Each representative of the sustainable team focused on a key component to champion in order to reach the project goal.

“Having everyone on board and working toward the same goal was perhaps the project’s largest success, given the challenges of a limited construction budget and a shortened construction schedule,” says Spear.

For sustainable elements that did not fit into the budget, the team looked to private sources for some funding. For instance, the Chesapeake Bay Foundation provided $100,000 for a 6,300-square-foot green roof above a concession/restroom area near the outfield.

Because all credits were submitted electronically, the entire sustainable team had real-time access to the LEED-credit submission process online. In total, the team amassed 34 points for a LEED Silver rating, including such sustainable design elements as:

· Treating and replacing contaminated soil at the ballpark site (a brownfield redevelopment)

· Burying six massive sand filters to mitigate any further pollution of the nearby Anacostia River

· Capitalizing on its urban accessibility to a variety of public transportation options, includingseveral metrorail lines to the north, bike trails and nine metro bus routes stopping at the site

· Incorporating high-efficiency field lighting to save an estimated $440,000 over a 25-year span (and strategically designed to minimize light spillage into nearby areas)

· Incorporating water-conserving plumbing fixtures to save 3.6 million gallons of water a year, and to reduce overall water consumption by 35 percent over the baseline

· Using air-cooled chillers instead of water-cooled chillers to save an additional 6 million gallons of water per year

· Installing more than 100 recycling bins for fan use

· Recycling 24,727 tons of construction waste diverted from landfills

· Incorporating a 6,300-square-foot green roof to infiltrate rain water and minimize heat gain to the atmosphere

· Specifying a ballpark maintenance plan that incorporates environmentally friendly cleaning products.

Storm-water management encompassed a significant portion of the sustainable design investment. Given the many pounds of organic material--hot dog buns, peanut shells and spilled beer, to name a few--collected after each ball game, it was imperative to find a solution to screen this organic debris from the storm-water system.

To accommodate, screens and debris guards are located in front of area drains in the lower and upper seating bowls as a first step in diverting solids. From there, the collected water is transmitted to six sand filters buried throughout the ballpark that screen runoff through the use of modified chambers. The water is screened once again, collected. and then pumped to the public storm-drain system.

“Looking back, we were able to do quite a bit because we had a talented team that was committed to the challenge,” says Spear. “We initially heard it would be $10 million to $20 million more than normal to build a LEED-Certified ballpark, but in the end, it was affordable--less than 2 percent of the construction cost.”

Implementing a variety of green elements helped the ballpark achieve notable projected savings in its first year:

· 70 percent of the project’s annual electric energy consumption purchased through a two-year agreement with Tradeable Renewable Certificates (meeting the Green-E definition for renewable power, or 14,600,706 kWh)

· Energy expenditure of 45.29 kBtu/SF/year, nearly half that of the average commercial building

· 82 percent of the building’s construction materials (24,727 tons) diverted from the waste stream

· $12,369 saved by installing high-efficiency field lighting (1,500-watt Green Generation lighting, never before used in a ballpark, and 22 percent more efficient than traditional field lighting); this lighting expected to save nearly $440,000 above over a 25-year span

· $18,400 saved by using water-conserving plumbing fixtures (2,565,000 gallons of water)·$30,689 saved by using air-cooled chillers instead of water-cooled chillers (4,275,000 gallons)

· More than half of all fans traveling to and from the ballpark via metrorail.

The sustainable team credits two items for its success, items any project team may use in achieving a green facility: having every team member on board with the same goal, and working with the U.S. Green Building Council to come up with creative solutions that respond to specific challenges of the building type.

Since its opening in March 2008, more than a million fans have visited the ballpark; these fans not only have reveled in the views of the Capital City but have also seen firsthand the benefits of a sustainable lifestyle.

“It was our hope to show fans that sustainability could be implemented at any scale,” says Spear. “We’re proud of our result--a fitting ballpark in the nation’s capital that serves as a model of sustainability for all Americans.”

As sustainability coordinator at HOK Sport, Stephanie Graham leads the firm’s efforts to incorporate sustainable design principles into office practices and into every project, including the eight current projects HOK Sport has registered. She also leads training efforts to help HOK employees become LEED-Accredited, and to educate them on topics related to sustainability. She can be contacted at stephanie.graham@hoksve.com