facilities renewal master plan - National Zoo - Smithsonian Institution

FACILITIES MASTER PLAN ENVIRONMENTAL ASSESSMENT
7:00 am and 7:00 pm on any weekday. Noise levels are not permitted to exceed 80 dBA
unless granted variance. For each larger development activities, SI would assess the
potential impacts to noise and seek to minimize noise levels during construction.
Operationally, Alternatives A, B, and C would not result in any substantial changes that
would affect noises levels at the National Zoo or to the surrounding properties. The road
and aerial trams would add a new noise source but the long-term impacts resulting from
each would be minor. For comparison purposes, the aerial tram noise would be
equivalent to that of a manual typewriter. Additional evaluation would occur to further
assess the impacts associated with the aerial tram. Renovation or the addition of
additional building systems such as heat pumps, air condition units, generators, etc. could
add an additional noise source to the environment that might be perceptible to nearby
residents at night. In each instance, SI would consider screening or noise abatement
measure to reduce noise levels from sensitive noise receptors such as nearby residences.
Overall, impacts associated with Alternatives A, B, and C would have minor short-term
and long-term adverse impacts on noise levels at the National Zoo because noise
generated from construction activities and other facilities improvements such as the road
and aerial trams could be perceptible from outside the National Zoo.
Mitigation for the Preferred Alternative
Temporary noise impacts will be minimized during construction or demolition activities
of individual projects by utilizing BMPs, as necessary, to meet the requirements of the
Washington, DC Noise Control Act of 1977. In accordance with the standards,
construction and demolition activity would be limited to between 7:00 am and 7:00 pm
on weekdays. If necessary, noise abatement would be used to attenuate excessive
construction noise in proximity of noise sensitive receptors. In addition, it is
recommended that construction specifications require selection of construction truck
routes that would minimize the potential for noise impacts to residences. Before
beginning construction on larger projects, a noise study will be performed and a
construction noise mitigation plan will be required. The plan will detail specific actions
to be taken by the contractor in order to minimize noise impacts and comply with DC
noise regulations.
B. Cultural Resources
B.1 Cultural Landscapes
The National Zoo is listed in the National Register of Historic Places (NRHP) as a
historic site. It is significant under National Register Criteria A and C as one of the
earliest zoological parks developed in the United States, and as a premier recreational
area for Washington, DC. Moreover, the National Zoo’s original plan was prepared by
Frederick Law Olmsted, whose idea of allotting a space for each type of animal that is
appropriate to its needs and indigenous habitat, revolutionized zoo design. As a cultural
landscape, the National Register Bulletin No. 18, How to Evaluate and Nominate
Designed Historic Landscapes details various types of designed historic landscapes. The
National Zoo has these characteristics of a cultural landscape:
SMITHSONIAN INSTITUTION – NATIONAL ZOOLOGICAL PARK 61 | P a g e