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Introduction and Themes of the Workshop

America’s national parks provide a wealth of experiences to millions of people every year. What visitors see—landscapes, wildlife, cultural activities—often lingers in memory for life. And what they hear adds a dimension that sight alone cannot provide.

Natural sounds can dramatically enhance visitors’ experience of many aspects of park environments. In some settings, such as the expanses of Yellowstone National Park, they can even be the best way to enjoy wildlife, because animals can be heard at much greater distances than they can be seen. Sounds can also be a natural complement to natural scenes, whether the rush of water over a rocky streambed or a ranger’s explanation of a park’s history. In other settings, such as the New Orleans Jazz National Historical Park, sounds are the main reason for visiting a park.

The acoustical environment is also important to the well-being of the parks themselves. Many species of wildlife depend on their hearing to find prey or avoid predators. If they cannot hear, their survival is jeopardized—and the parks where they live may in turn lose part of their natural heritage.

For all these reasons it is important to be aware of noise (defined as unwanted sound, and in this case usually generated by humans or machinery), which can degrade the acoustical environment, or soundscape, of parks. Just as smog smudges the visual horizon, noise obscures the listening horizon for both visitors and wildlife. This is especially true in places, such as remote wilderness areas, where extremely low sound levels are common.

The National Park Service (NPS) has determined that park facilities, operations, and maintenance activities produce a substantial portion of

noise in national parks and thus recognizes the need to provide park managers with guidance for protecting the natural soundscape from such noise. Therefore, the focus of the workshop was to define what park managers can do to control noise from facilities, operations, and maintenance, and not on issues such as the effects of noise on wildlife, noise metrics, and related topics.

To aid in this effort, NPS joined with the National Academy of Engineering (NAE) and with the US Department of Transportation’s John A. Volpe National Transportation Systems Center to hold a workshop to examine the challenges and opportunities facing the nation’s array of parks. Entitled “Protecting National Park Soundscapes: Best Available Technologies and Practices for Reducing Park-Generated Noise,” the workshop took place October 3–4, 2012, at NPS’s Natural Resource Program Center in Fort Collins, Colorado.

ORIGINS OF THE WORKSHOP

The workshop grew in part from a 2010 NAE report, Technology for a Quieter America, which concluded that “reducing the noise levels to which Americans are exposed will require cooperation among engineers, industrial management, and government in many disciplines, and it will not be accomplished in a short time. Nevertheless, reduced noise levels will contribute to improved quality of life for many Americans.”

The report made many observations and recommendations that relate to issues of concern to the Park Service, said George Maling, chair of the authoring committee, who briefly summarized the report’s conclusions at the workshop. It did not recommend a single noise metric for quiet areas such as parks, but carefully examined the need for metrics and their uses. It also investigated issues relating to occupational noise, hazardous noise, low-noise-emission products, and the role of government agencies such as the Environmental Protection Agency (EPA) in regulating noise levels. Maling noted that several follow-on activities have occurred since the release of the report, including a workshop on motorcycle noise.

At about the same time the report came out, NPS was conducting a survey of park superintendents about noise and other issues. The survey results revealed problems with excessive noise in national parks and served as an additional impetus for this workshop, which sought to examine noise in national parks that can be controlled by the Park Service itself, review the issues raised in Technology for a Quieter America, and apply that report’s relevant recommendations to the parks.

“We’ve been spreading the gospel of natural sounds and trying to reduce noise,” said Bert Frost, associate director for the NPS Natural Resource Stewardship and Science Directorate, “but we haven’t had those conversations internally.” The Park Service needs to “lead by example,” added Frost. If it does, it will have a much stronger case in asking others to do the same in the areas it protects and conserves.

ORGANIZATION OF THE BREAKOUT GROUPS

After the plenary presentations, the workshop participants divided into breakout groups focused on transportation, facilities and maintenance, and construction. Box 1-1 presents the general guidance provided to the three groups.

Chapters 3, 4, and 5 convey the reports from representatives of the breakout groups in the final plenary session. These reports should not be interpreted as recommendations of the workshop or of the breakout groups.

THEMES OF THE WORKSHOP

Several major themes emerged from the presentations in the initial plenary session and from the reports of the breakout groups. These themes are presented not as conclusions or recommendations but as organizing principles for future discussions and follow-up.

Themes from Plenary Presentations

• The Park Service has a mandate to protect the acoustic environment and specific policies designed to implement that mandate.
• Many sources of noise in parks originate in park operations, maintenance, and construction.
• Population growth and increased traffic are expected to increase noise in and around parks.
• Noise has substantial effects both on wildlife and on human visitors to parks.
• Every park is unique and needs to adapt policies to its own situation.

Themes from the Breakout Group on Transportation

• Maintenance is one of the simplest and most effective ways to control noise and improve the functionality, safety, and fuel efficiency of vehicles.
• A parkwide database could include a ranking of each piece of equipment by the noise produced per mile traveled and be used to prioritize maintenance, use, and replacement.

• Turning off idling vehicles, using auxiliary power units, or moving vehicles to sheltered locations can reduce noise in parks, particularly at the most visited locations, such as overlooks.
• Technological options such as quiet pavements, new kinds of backup alarms, quieter engines and tires, and short berms along-side roads offer potential ways to reduce noise.
• Quiet zones, quiet times, reduced speeds, and scheduling of transit can limit noise at sensitive times, such as dusk and dawn when wildlife activity tends to be more prevalent.
• Communication through the latest technologies, such as Twitter, Facebook, and texting, should be considered.

Themes from the Breakout Group on Facilities and Maintenance

• A construction guide for park employees could help them prepare for construction projects by, for example, establishing noise metrics and noise limits for the project.
• Noisy operations can be limited or reduced through scheduling, relocation of noisy work elsewhere, or use of different equipment.
• A database of existing equipment and of noise-producing operations could inform park operations and maintenance of the best procedures for reducing noise.
• Involving concessionaires and other stakeholders in discussions and decisions can build understanding and support for low-noise policies.
• Guidelines for buying quieter products and mitigation strategies for existing equipment can be included in planning and contracts.

Themes from the Breakout Group on Construction

• Flexibility and good practice are both necessary to make effective tradeoffs among the duration, noise levels, and cost of construction projects.
• Noise can be limited at its source through measures such as scheduling, equipment restrictions, better maintenance, reduced power operations, quieter backup alarms, and noise compliance monitoring.

• Barriers, enclosures, or increased distance can buffer noise for those within hearing range.
• The impacts of noise on people within hearing range can be limited through soundproofing, receptor noise limits, stakeholder meetings, noise complaint processes, or temporary relocation.
• A noise mitigation or control plan can be written into contracts and used to hold a contractor accountable.
• A training program and guidance manual for park managers could demonstrate noise specification and compliance measures.

STRUCTURE OF THIS REPORT

Chapter 2 draws on the initial plenary session of the workshop to provide background on the issue of noise in the national parks. Chapters 3, 4, and 5 summarize the observations of three breakout groups that examined transportation, facilities and maintenance, and construction, respectively. These chapters are based on the reports of breakout group members in the concluding plenary session of the workshop. Chapter 6 conveys the reflections of workshop participants on the breakout reports and on the workshop as a whole.