When pieces are damaged onsite, they must be shipped to
a warehouse for evaluation before being transported to a conservator.
Without proper emergency storage and stabilization, damaged pieces
can potentially be further damaged during shipment. Any loss of
museum pieces is irretrievable.
Natural Resources
Subsoils and Groundwater Considerations
No new underground development would be proposed that would
affect or be affected by subsoil and groundwater conditions. Ongoing
surface replacement activities (sidewalks and other infrastructure)
could require the replacement of some fill with appropriate soils.
Impacts on Water Resources
No change to the quality and quantity of surface or ground
waters would occur as a result of ongoing visitor, special event,
and Executive Office activities within the study area.
Impacts on Vegetation and Soils
Existing vegetation patterns through the study area would remain,
with changes only occurring as a result of existing visitor use
and special events, minor construction projects, and natural mortality
of individual plants. The number and location of special events
and the current White House tour program would continue to provide
substantial stress on the trees, soils, and turf of the Ellipse.
Soil degradation due to intense use would continue to affect
plant materials and drain-
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Impacts of the No-Action Alternative: Home
and Office President
age. Resources such as the American elms on the Ellipse would
receive attention in accordance with the best current management
practices but only to solve immediate problems and would include
such methods as spraying, selective removal of individual trees,
and substitution of hybrid breeds as they became available.
The steamline would continue to affect turf across the center
of the Ellipse throughout the year.
Home and Office of the President
Impacts on Executive Residence Operations
Analysis
Indoor Recreation Space. Informal, indoor recreation
space within the secured White House complex would continue to
he limited. Future first families would have to go outside the
White House for these opportunities, and security precautions
at these facilities would affect others' use of such facilities.
Future first families with young children could find the White
House a difficult space in which to rear children.
Privacy. Staff would continue to move through the
lower floors of the Executive Residence during the day, infringing
some-what on privacy for the first family. The need to go outside
the White House for recreational opportunities would also limit
privacy for the first family.
Storage. The lack of storage would continue to require
that furnishings, materials, and supplies used frequently in the
Executive Residence be stored offsite and brought into the complex
when needed. These repeated operations would be inefficient and
costly in terms of staff time' transportation logistics, and security
checks. Corridors, stairwells, work spaces, and other inappropriate
locations in the White House would continue to be used to store
items, creating unsafe situations for staff moving through these
areas and making it difficult to retrieve supplies. A lack of
work space would continue to affect the efficiency of Executive
Residence operations.
Public Access. As described for the proposed plan,
die desire for public access to the White House would continue,
and multiple uses of the site would have to be coordinated to
allow public tours.
Conclusion
Existing problems within the Executive Residence related
to privacy and onsite amenities for future first families would
continue. The lack of adequate onsite storage space would still
cause safety hazards, result in the costly movement of supplies
and furniture, and the inappropriate use of existing space.
Impacts on Executive Office Support Services
Analysis
Visitor Arrivals. Thousands of diplomatic and business
visitors enter the White House complex each year and thousands
of individuals attend meetings and events inside the area. Visitors
would continue to enter the complex at multiple access points
and be greeted at entrances to the East and West Wings and at
the north and south porticos.
Meeting Space. Meetings that could not be accommodated
in existing meeting rooms would probably continue to be held in
historic rooms at the site. Poor acoustics, the lack of infrastructure
for state-of-the-art communications systems (such as audiovisual
and
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ENVIRONMENTAL CONSEQUENCES
teleconferencing equipment), and the lack of space would make
it difficult to accommodate existing needs. Finding appropriate
meeting space would continue to be a problem for staff at the
site.
Parking. Vehicles used by senior staff and diplomats
would continue to be parked on East and West Executive Avenues,
State and Hamilton Places, and other street locations, causing
congestion for pedestrians and vehicular traffic. Staff parking
would be near the White House, but no protection from inclement
weather would be provided. Parked vehicles would still result
in conflicts with deliveries. Presidential motorcades would continue
to be staged throughout the site.
Parking for other staff would continue to be provided on
the Ellipse roadways and adjacent streets, with staff sometimes
competing for limited parking spaces. Staff vehicles would still
be the target of some vandalism and damage.
Deliveries. deliveries would continue at various
surface locations, resulting in conflicts between delivery trucks,
parked vehicles, pedestrians, and service equipment within the
White House complex. After being unloaded, items would be moved
about the site by way of common spaces used by the first family,
staff, business visitors, and vehicles, causing additional conflicts
and congestion.
Site Circulation. Staff would use present access
corridors to move about the site, including the ground floor of
the White House. The storage of items in offices, corridors, and
alleyways would impede circulation and cause unsafe conditions.
Staff use of the ground floor of the residence would impact public
tours and contribute to congestion and crowding.
Conclusion
Physical and visual congestion at the White House and President's
Park by vehicles and the movement of materials and staff through
public and private areas would continue to contribute to a feeling
of disorganization and confusion throughout the White House complex.
Meetings that could not be accommodated in limited meeting
rooms would likely be held in historic rooms throughout the site,
which have poor acoustics and lack appropriate infrastructure.
Impacts on News Media Facilities
Analysis
The existing presidential briefing facilities and media
work space would be used. These areas are extremely crowded and
utilities are inadequate for existing needs. Work space is poor,
and there is no space to store broadcast equipment, so any temporarily
vacant spaces, as well as entrances and exits, are used to store
equipment, causing safety concerns. Out-of-town and international
press representatives cannot be accommodated.
Conclusion
News media facilities would remain over-crowded and utilities
inadequate.
Visitor Experience
Impacts on Diplomatic and Business Visitors
Diplomatic and business visitors to the White House would
find no change in their experiences. Visitors could continue to
enter the
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Impacts of the No-Action Alternative: Visitor
Experience
West Wing on the surface, while their vehicles would park on
West Executive Avenue. Visitors could notice a lack of consistency
in design elements used throughout President's Park and the White
House. Vehicle parking on the White House grounds would intrude
on the formality of the setting.
Impacts on Public Visitors
Analysis
Initial Impressions. The expectations of first -time
visitors to President's Park would probably continue to be compromised
by the presence of vendors along curb lines, by vehicles parked
throughout the area, and by the inconsistent use of materials
on the site. Buses parked within sight lines to and from the White
House would detract from the visitor experience by blocking views,
creating noise, emitting diesel fumes, and compromising the site's
dignity and ceremonial value. There would be no sense of arrival
for visitors, signifying that they were in a special, historic
place.
Information/Orientation. Visitors would continue
to receive limited information in advance about the White House
and public tours. There would be no welcoming or orientation points
for visitors as they entered President's Park. Information in
other languages would continue to be limited.
Visitor Center. The present visitor center in the
Commerce Building would provide limited space for exhibits and
visitor orientation prior to White House tours. White House Historical
Association sales items would still be offered, making it easy
for visitors to buy educational materials.
Visitors who could not participate in the White House public
tours would be able to view limited exhibits about the White House
and the presidency in the visitor center.
Interpretation and Education. Present educational
materials and programs would offer visitors minimal opportunities
to learn about the site and its historical significance. Out-reach
programs would be restricted.
White House Tours. Visitors taking public tours
of the White House would continue to be exposed to traffic hazards
as they crossed 15th Street and E Street, walking from the visitor
center in the Commerce Building to the visitor entrance building.
While waiting for tours to begin, visitors would continue to queue
up out of doors on the Ellipse regardless of weather conditions.
Mobility-impaired visitors would still use the northeast gate
and enter the White House through the north portico.
Public Amenities. Few public amenities would be
available. Those that are offered would still have an inappropriate
or temporary appearance, such as the blue plastic water fountains.
Conclusion
Expectations of first-time visitors to President's Park
would probably be compromised by activities and uses that do not
reflect the dignity of the site. Information about activities
and White House tours would be somewhat hard for visitors to find,
especially after the visitor center in the Commerce Building had
closed. While the visitor center would help meet information and
interpretive needs, space would be inadequate for indoor staging
of public White House tours or for extensively interpreting the
significance of the site and the history of the presidency.
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ENVIRONMENTAL CONSEQUENCES
Impacts on Pedestrians
Analysis
Pedestrians entering President's Park from the north would
cross H Street and walk through Lafayette Park or along Jackson
or Madison Place Pedestrians would encounter a constant flow of
visitors and commuters but no heavy crowded or congested conditions.
Pedestrians entering the site from Hamilton Place south
of the Treasury Building and from State Place south of the Old
Executive Office Building would encounter parked vehicles, the
continual movement of staff cars and service trucks, narrow traffic
lanes, and security barriers. Pedestrian use along East Executive
Park would continue to be especially heavy in the morning due
to access by local residents, staff, casual visitors, and tourists
waiting in line for White House tours. West Executive Avenue would
not be open to the public.
E Street would continue to be a major obstacle for pedestrian
movements as a result of two traffic lanes. Mid-block traffic
signals east of 15th and west of 17th Street help pedestrians
cross the street, particularly tourist groups of 250 people (from
10 A.M. to noon), but the short timing sequence usually does not
allow all pedestrians to cross safely. One-third of pedestrian
crossings would continue to occur outside the crosswalks, and
pedestrian/traffic conflicts on E Street would continue.
Pedestrians crossing the south side of the park from any
direction would still have to contend with parked vehicles and
traffic along the roadways.
Conclusion
Present barriers to pedestrian movements to and through
the site, including traffic and parked vehicles, would remain.
Impacts on Local Residents
Passive and active recreational uses would be allowed to
continue on the Ellipse.
Noise Impacts
The main noise source would continue to be traffic. Noise
levels resulting from activities in President's Park would be
similar to present noise levels. Short-term noise impacts associated
with individual construction projects would continue. No new permanent
noise sources would be created.
Special Events
Impacts on Public Events
Various special events, some of which would occur over
long periods of time, would continue within President's Park,
particularly on the Ellipse. Depending on the intensity of events
and their duration, the time it takes the site to recover after
events could be lengthy.
The annual Pageant of Peace would continue in its current
setup in the northeast center of the Ellipse. Setup would begin
in October, with dismantling and restoration of the turf sometimes
taking until May or potentially longer. Conflicts between pageant
dismantling activities and public tour operations starting on
the Ellipse in March would also continue. The possibility of staging
other events on the Ellipse would be limited by the prolonged
removal of infrastructure for the pageant.
Impacts on White House Events
Storage and work space to prepare for events would remain
limited. Many event-related items would be stored offsite and
shuttled to and from the White House as needed. Many
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Impacts of the No-Action Alternative: Transportation
use conflicts, such as multiple deliveries and inadequate work
spaces, would create logistical problems in preparing for and
staging events.
Utilities would likely be upgraded, where feasible, to
support the many functions at the White House.
Staging for garden and Christmas candlelight tours would
continue outside the visitor en-trance building and around the
south fence. No protection from inclement weather would be available.
The Ellipse would continue to be available for staging activities
associated with the Easter egg roll.
Transportation
Impacts on Access and Circulation
Under the no-action alternative E Street would remain a
one-way eastbound street, and no changes are anticipated to the
downtown street system. As described in the "Affected Environment,"
eastbound Constitution Avenue operates under capacity (LOS C or
better) throughout the day. In the morning peak period both H
and L Streets operate slightly under capacity, and K Street at
capacity. Within President's Park, E Street operates under capacity
during the morning peak period. In the afternoon peak period,
E, H. K, and L Streets all operate either at or over capacity,
resulting in slow speeds and stopped delays. Except for I Street,
the westbound streets, including Constitution, K, and M, all operate
under capacity during both the morning and afternoon peak periods.
I street operates over capacity during both periods.
The northbound segments of 17th Street between Constitution
Avenue and State Place, 15th Street north of Pennsylvania Avenue,
and 14th Street between Pennsylvania Avenue South and New York
Avenue operate over capacity in the morning peak period. In the
afternoon peak period, north-south streets in both directions
generally operate under capacity between Pennsylvania Avenue and
Constitution Avenue. North of Pennsylvania Avenue, only the southbound
segments operate at or over capacity.
Temporary closures of E Street for special events, dignitaries'
arrivals or departures, and presidential movements would continue.
The trend in recent years is that these temporary closures are
occurring more frequently. Based on this trend, it is likely that
E Street would be closed more and more often, causing greater
traffic congestion on adjacent streets as drivers tried to find
alternate routes.
Impacts on Public Parking
There would be no changes to the existing on-street parking
supply. The public would continue to search for parking because
existing on-street parking is limited.
Impacts on Public Transit
The Metrorail stations would not be impacted by President's
Park activities, nor would the Metrobus terminals, bus stops,
routes or operations.
Impacts on Tour Buses
Tour buses would continue their present use of the site,
with some parking within sight lines of the White House and causing
obstacles for pedestrians and traffic. Since parking for tour
buses is limited, buses would continue to park in non designated
spaces or circulate, contributing to traffic congestion and exhaust
emissions. As described for the proposed plan, future planning
by both the District of Columbia and the National Capital Planning
Commission to coordinate mass transit
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ENVIRONMENTAL CONSEQUENCES
proposals and centralized tour bus parking lo-cations outside
the downtown area would help reduce tour bus impacts within and
near President's Park.
Tour buses could continue offering drive-by views of the
White House along E and H Streets.
Impacts on the Tourmobile
Continued operation of the Tourmobile on existing routes
would not affect traffic circulation on the site and would be
a convenient means of transportation for tourists within the Memorial
Core.
Impacts on Bicyclists
There would be no impacts to the regional or D.C. bicycle
route system. Conditions for bicyclists in the study area would
not change. Except for Pennsylvania Avenue, bicyclists would travel
on streets with traffic.
Socioeconomic Environment
Impacts on D.C. Revenues
Parking Revenues. No parking meter spaces would be removed,
therefore there would be no impact to D.C. parking revenues.
Vendor Revenues. No vendor spaces would be removed, therefore
there would be no impact to D.C. vendor license and sales tax
revenues.
Impacts on Vendors
Vendor spaces would remain so there would be no loss of
vendors' jobs or business revenue.
Impacts on Local Businesses
Parking spaces along 17th Street, 15th Street, and E Street
would remain, and the parking supply available for leases would
not change. Therefore, parking available to businesses and agencies
would not change.
Construction Impacts
There would be no economic impacts associated with construction
under this alternative other than minor benefits from ongoing
facility maintenance or upgrades (such as those related to the
"Greening of the White House").
Site Management and Operations
Impacts on Site Operations
Residence and business arrivals would have minimal effects
on site operations.
Using historic rooms in the White House, the Old Executive
Office Building, and the Treasury Building for meetings would
require staff time to set rooms up, to transport equipment and
materials to and from offsite storage areas, and to put rooms
back in order.
To ensure the protection of significant resources throughout
President's Park, an increase in staff could be required. While
the White House grounds are always maintained to the highest possible
standards, insufficient staffing and operating funds have precluded
comparable maintenance practices in Lafayette Park and the Ellipse.
Impacts on Maintenance
The efficiency of maintenance operations within President's
Park would continue to be affected by the offsite location of
key support services and storage for large equipment and
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No-Action Alternative Cumulative Impacts
bulk materials. Travel times to and from off-site supply bases
would reduce efficiency. Managerial and administrative staff and
storage for small equipment and supplies would still be distributed
in several different facilities throughout President's Park.
Maintenance equipment materials arid supplies for the White
House grounds would continue to be housed in a facility that is
often inadequate for maintenance operations.
Impacts on Utilities
Utility systems throughout the site would be upgraded as
needed. Existing utility corridors would be affected by individual
construction projects throughout President's Park.
Irreversible and Irretrievable Commitments
of Resources
Arrangements for staging White House public tours-queuing
on the Ellipse, traffic conflicts while crossing E Street, and
exposure to poor weather could continue to detract from the overall
experience of a site visit. A less than satisfactory White House
tour experience would be an irretrievable loss of time, energy,
and money spent by visitors, particularly those from outside the
region.
Allowing surface parking within the White House complex
and President's Park would continue to deprive the public of opportunities
to view the landscape as it was intended to be seen by the original
designers and cause conflicts with numerous site users.
Cumulative Impacts
Continuing existing conditions for visitors to the White
House and President's Park would do clothing to improve the overall
experience for visitors to Washington. For a more complete understanding
of the history of the presidency, visitors would have to visit
numerous sites, such as the Smithsonian Institution museums and
individual presidential sites.
Relationship to Other Plans and
Efforts
Many management strategies and current elements within
President's Park would continue to be inconsistent with the elements
and objectives of other plans (listed in "Relationship of
this Document to Other Plans and Efforts"). E Street would
continue to divide the historic landscape. Cars would continue
to be parked within historic vistas. These actions ore not consistent
with the "Preservation and Historic Feature" element
of theft Comprehensive Plan for the National Capital. Because
of parked cars, continued conflicts between vehicles and pedestrians
would occur daily, and a pedestrian-friendly environment would
not prevail.
Retaining E Street as a one-way eastbound street would
be consistent with NCPC's Extending the Legacy plan, which identified
E Street as a secondary connector in the city's transportation
system.
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IMPACTS OF ALTERNATIVE 1
Cultural Resources
Impacts on the Cultural Landscape
Analysts
Removing parked vehicles within President's Park would
improve the quality of vistas across the Ellipse area to the Washington
Monument and the Jefferson Memorial as seen from the White House
or the south grounds. However, making E Street a four-lane roadway,
without landscaped medians, would intrude on the decorum of the
site and would further separate President's Park from the Ellipse
area.
As described for the proposed plan, establishing formal
entryways would introduce new architectural elements to the site
and focus visitor traffic at these points. Implementing Design
Guidelines for the site would help ensure that design elements
and materials were consistent throughout the site, helping create
a unified character for the White House and President's Park.
Similar to the proposed plan, historic views could temporarily
be affected by the storage of construction equipment, supplies,
and structures. More construction would occur under this alternative
than under the proposed plan. Vistas to the north and south would
be intruded upon by parking garage and visitor center construction,
although not at the same time.
Resource Management. No additional memorials within
President's Park would be encouraged, helping minimize any additional
intrusions on existing views.
Home and Ounce of the President. As described for
the proposed plan, constructing a new 290-space parking structure
under Pennsylvania Avenue and an 850-space structure underground
on the Ellipse would allow the removal of surface parking. However,
access portals on the north end of West Executive Avenue and on
the south side of the Ellipse, as well as traffic entering and
leaving the garages, would be new intrusions on historic and formal
vistas to and from the White House. Locating pedestrian access
points to the Ellipse parking south of E Street would avoid any
potential impacts on First Division Monument and Sherman Park.
Ventilation systems, pedestrian access points, and emergency exits
would need to be designed to minimize any additional adverse effects
on the landscape.
Under this alternative building a 170-space parking facility
under the south plaza of the Treasury Building (a national historic
land-mark) would require entrance and exit portals within the
right-of-way for Hamilton Place, intruding on the historic south
approach to this historic structure. It would be impossible to
completely screen the portals, and they would be a new visual
intrusion on the landscape
As described for the proposed plan, a new meeting/conference
facility under West Executive Avenue would be adjacent to the
Old Executive Office Building (a national historic landmark),
and the northside parking garage would be adjacent to the Lafayette
Square National Historic Landmark District and near the Treasury
Building. Under this alternative the Ellipse and eastside parking
facilities would potentially affect the setting of nearby historic
structures and districts, including the Old Executive Office Building,
Treasury Building,
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Impacts of Alternative 1: Cultural Resources
Fifteenth Street Financial Historic District, Pennsylvania
Avenue National Historic Site, Federal Triangle Historic District,
and Seventeenth Street Historic Area. Potential impacts from construction
on the settings of these historic resources would need to be mitigated
through sensitive design. There would be more potential intrusions
on President's Park South under this alternative than any other.
Constructing a staff circulation corridor along the north
side of the White House, as de-scribed for the proposed plan,
would put two fern-leaf beeches near the west wing (one planted
by President Johnson in 1968, and one by President Nixon in 1972)
at risk.
Also, an estimated 24 trees on the Ellipse would be permanently
lost as a result of constructing the parking facility, utilities,
and pedestrian and vehicular corridors. Depending on the method
of construction (tunneling or surface excavation), up to 31 additional
trees could be at risk. These trees contribute to the present
character of the Ellipse, and the loss would be an adverse effect
on the cultural landscape.
The redesign of West Executive Avenue would be handled
in such a way as to retain the general character of a roadway.
Providing deliveries at a renovated facility in the New
Executive Office Building, with underground deliveries to the
White House complex, would reduce surface activities and improve
the appearance and decorum of the site as both an executive office
and residence.
As described for the proposed plan, redesigning the present
NPS grounds maintenance facility on the south grounds of the White
House would affect the landscape during construction, but proper
design would mitigate any adverse visual effects.
Visitor Use and Services. An underground visitor center
on the Ellipse would serve large numbers of visitors and would
require a large entrance area. The entrance would add an architectural
element to the site, potentially intruding on the landscape and
compromising the formal nature and dignity of the space. The settings
of adjacent historic structures and districts, including the Fifteenth
Street Financial Historic District, the Pennsylvania Avenue National
Historic Site, and the Federal Triangle Historic District, could
be affected.
Visitors would enter the White House visitor entrance building
directly from the visitor center, requiring a redesign for this
facility to accommodate an escalator, a stairway, and an elevator.
Any redesign would need to ensure that the design complemented
the present site character.
An E Street pedestrian underpass to Lily Triangle would
require this location to be redesigned and the construction of
an entry portal. The effect of the entry portal could be mitigated
by design and placement.
Public recreation would be continued on the Ellipse, but
passive activities would be encouraged, helping preserve the park's
formal and ceremonial vistas.
Special Events. Events would be scheduled that reflect
the dignity and purpose of the White House and President's Park.
Reducing the scale of events would help protect formal vistas
and enhance the dignity of the area. Dispersing events around
the Ellipse would allow additional time for turf and garden areas
to recover from previous events, contributing to an overall improvement
in the appearance of President's Park South.
Transportation. Making E Street a four-lane thoroughfare
through President's Park would substantially compromise the formal
setting of the entire area, separating what designers perceived
of as an integrated site into two distinct parcels. The Ellipse
could be at greater risk for inappropriate uses because it
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ENVIRONMENTAL CONSEQUENCES
would not be perceived as related to the White House and President's
Park. Park lands would be lost through a widening of E Street.
Properties on the National Register of Historic Places between
17th and 18th Streets would be compromised as a result of widening
E Street. Noise from four lanes of traffic could detract from
the formal setting of President's Park and nearby historic districts.
As described for the proposed plan, preparing a future
citywide tour bus management plan (in cooperation with the National
Capital Planning Commission and the District of Columbia) and
designating tour bus passenger dropoff and pickup points would
eliminate bus parking within historic sight lines and lessen traffic
noise and confusion.
Conclusion
Impacts would be similar to those described for the proposed
plan except for the following:
* A new entry to a belowground visitor center on the Ellipse
and entrance portals to a parking/delivery facility south of
the Treasury Building, as well as to an Ellipse parking and maintenance
facility, would permanently intrude on formal vistas. Once these
facilities were in place. incompatible activities on the surface
would be reduced, hut there would be more new intrusions on the
southern portion of the park under this alternative than any
other. Two commemorative plantings on the White House grounds
could be damaged or lost as a result of construction.
* Making E Street a four-lane roadway would substantially
compromise the character of the entire area and divide the Ellipse
from the rest of the park. Park lands would be used to widen
the street.
Impacts on Archeological Resources
Analysis
As described for the proposed plan, archeological resources
would be protected overall through an organized program for surveying,
testing, and recording archeological resources, preparing a survey
for the property, and making the collection available for study
by scholars.
Actions under this alternative that could affect archeological
resources include (1) a meeting/ conference facility under West
Executive Avenue, a 290-vehicle parking garage under Pennsylvania
Avenue, and an 850-space parking garage and 4,000-square-foot
maintenance facility beneath the Ellipse (all the same as the
proposed plan), (2) first family recreation space and news media
facilities under West Executive Avenue, (3) a 66,000-square-foot
visitor center under the northeast section of the Ellipse, (4)
a 1 70-space parking/delivery facility beneath the south plaza
of the Treasury Building, (5) nine underground pedestrian, vehicle,
and service corridors, and (6) a rerouted Ellipse steamline (the
same as the proposed plan). As described for the proposed plan,
any disturbance of archeological resources during excavations
could be mitigated through survey, monitoring, and recordation.
However, disturbance would be substantial, and mitigation would
be both expensive and time consuming.
Conclusion
More archeological resources would be subject to disturbance
under this alternative than any other alternative. Any disturbance
could be mitigated through survey, monitoring, and recordation;
however, given the extent of disturbance, mitigation could be
time consuming and costly.
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Impacts of Alternative 1: Cultural Resources
Impacts on Historic Buildings and Structures
Analysis
Home and Office of the President. Executive Residence-As
described for the proposed plan, providing indoor recreation space
for the first family would help meet existing needs and minimize
the potential for future impacts on historic resources and the
surrounding cultural landscape. Through proper redesign of the
present NPS grounds maintenance facility on the south grounds
of the White House' visual effects from the facility on the cultural
landscape could be mitigated.
Executive Office Support Services -The following
impacts would be the same as those described for the proposed
plan:
*A new underground facility for meetings would relieve some
impacts on historic resources by offering an alternative location
for these activities and focusing events at one location. The
proposed development beneath West Executive Avenue would be adjacent
to two national historic landmarks - the Old Executive Office
Building and Lafayette Square National Historic Landmark District.
Any potential impacts would need to be mitigated through sensitive
design.
*Garage air and filtering systems in under-ground parking
facilities would lessen the potential for some air pollution
and air-borne pollutant damage to stone and metallic resources.
Impacts related to traffic on the site, including motorcades
and security vehicles, would be minimal.
*Security measures would continue to have effects on cultural
resources, including the cultural landscape, by the placement
of material and equipment in the landscape and potentially affecting
the historic fabric of the White House.
Mitigations for effects would be developed through a continuing
dialogue between the National Park Service and the U.S. Secret
Service.
Under this alternative constructing a 170 - space parking
facility under the south plaza of Treasury Building (a national
historic land-mark) could affect this structure's foundation.
The foundations date from 1836 60 and vary from concrete to rubble
to wood pilings. Possible effects that would have to be mitigated
include dewatering problems and other stability questions. Parking
garage portals south of the Treasury Building would be permanent
new intrusions on the historic landscape.
News Media - Similar to the proposed plan, developing
news media facilities below West Executive Avenue would help reduce
resource degradation by providing wider corridors for circulation
and increasing work space.
Visitor Use and Services. The entrance to a visitor
center in the northeast portion of the Ellipse would be within
sight of the Treasury Building, and potential impacts on the historic
setting would need to be mitigated through sensitive design.
Transportation. Widening E Street to four lanes
would require the use of an undetermined amount of park property
in President's Park South.
Site Operations. Providing an onsite maintenance
facility for President's Park would eliminate the need to use
historic structures (such as the Bulfinch gatehouses) in inappropriate
ways.
Conclusion
The following impacts would be similar to the proposed plan:
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ENVIRONMENTAL CONSEQUENCES
* A more proactive resource management program for historic
buildings and structures would help ensure the continued protection
of the historic fabric of nationally significant resources. Providing
new facilities for meetings would help relieve the overuse of
historic rooms and the subsequent deterioration of historic fabric.
* An onsite maintenance facility for President's Park would
eliminate inappropriate uses of historic structures.
* Security measures would continue to affect historic buildings
and structures, but adverse effects could be mitigated by continued
consultation between cultural resource and security agencies.
Under this alternative constructing a parking garage under
the south plaza of the Treasury Building could result in foundation
dewatering problems and other stability questions. Garage entrance
portals, portals to an E Street underpass at Lily Triangle, and
an entrance to a visitor center in the northeast portion of the
Ellipse would be permanent intrusions on the historic setting
of the Treasury Building and within sight of nearby historic districts.
Potential impacts would need to be mitigated through sensitive
design
Impacts on Fine and Decorative Arts
As described for the proposed plan, providing proper emergency
storage and stabilization facilities for the White House museum
collection would help ensure that valuable pieces would be protected
from damage or loss. This facility would also allow some pieces
to be kept onsite, reducing the potential for damage during shipment.
Natural Resources
As described for the proposed plan, the construction of
new belowground facilities could affect and be affected by subsoil
and ground-water conditions within the study area. Construction
could also cause changes in vegetation patterns. Appendix E lists
the proposed construction method (cut/cover or tunneling) for
each underground structure. Vegetation and soil mitigation measures
that would be employed during construction to protect vegetation
are outlined in the "Mitigating Measures" section
Also as described for the proposed plan, many of the facilities
have only been conceptually designed. When final designs were
undertaken (once a proposed plan has been approved and funding
acquired), an environmental assessment would be conducted (1)
to analyze site- specific impacts, (2) to ensure that all facilities
and design details are in concurrence with the proposals and guidelines
presented in this document, and (3) to identify measures to minimize
or mitigate impacts to all resources and site activities
Geotechnical Considerations: Soils and Groundwater
Analysis
Geotechnical site constraints would be generally the same
as those outlined for the proposed plan. Particular structures
that could be affected by subsurface conditions include the staff
perking garage and visitor center, both of which would be under
the Ellipse All or a portion of the existing fill in the two construction
areas might have to be replaced with properly compacted structural
fill, and even though conventional cut-and-cover construction
techniques would be suitable, site conditions could require that
the excavations be shored. A permanent drain or dewatering
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Impacts of Alternative 1: Natural Resources
system might need to be installed to control groundwater both
during and after construction. The structures would also need
to be designed for hydrostatic uplift.
Tunneling in the natural clayey silts and silts might be
feasible in areas such as the E Street underpass. However, site-specific
investigations should be conducted at this location to determine
if the existing fill materials could sustain tunneling operations.
As suggested for the proposed plan, additional soil borings
and monitoring wells would be required throughout the study area
before the final design of any proposed underground structures.
Hazardous materials investigations would also be conducted, as
described for the proposed plan.
Conclusion
As described for the proposed plan, all proposed underground
structures would be feasible, given known geotechnical characteristics
(see the proposed plan for specific requirements). Where information
is incomplete, site specific studies would be required during
design development, such as additional soil borings, groundwater
monitoring wells, and hazardous materials investigations.
Impacts on Water Resources
Surface Water
Analysis
Even though the amount of development would be greater
under this alternative than the proposed plan, there should be
no noticeable permanent change in the volume of stormwater runoff
over the short or long term. Appropriate stormwater management
practices and erosion control measures would be implemented in
the design and construction of both surface and underground structures.
The reduction in aboveground parking on the Ellipse and West Executive
Avenue would reduce the amount of oil, gas, and other wastes that
would enter the stormwater system through runoff:
Conclusion. As described for the proposed plan, no long-term
changes in stormwater volumes or effects on surface water quantity
or quality are anticipated.
Groundwater
Analysis. As noted in the geotechnical evaluation,
the development of a parking garage and visitor center under the
Ellipse could require a permanent drain or dewatering system.
Such a system could potentially lower the local groundwater table.
Further ground-water studies, in the form of research and groundwater
monitoring wells, would be required before design development.
Conclusion. Groundwater quantity and quality would
probably not be affected by pro-posed structures. Thorough, site-specific
groundwater wells and testing would be conducted before any construction
to ensure that effects would be minimized.
Impacts on Vegetation and Soils
Analysis
As discussed for the proposed plan, any trees or shrubs
removed or lost during construction would be replaced in kind
with stock from an NPS nursery or other cooperating horticultural
institutions; however, the plants would likely vary in size from
existing vegetation. Some trees would be permanently lost and
not replaced. Damage to commemorative trees would be avoided where
possible.
White House Grounds and West Executive Avenue. The excavations
on the White House grounds would be similar to those described
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ENVIRONMENTAL CONSEQUENCES
under the proposed plan, although less in number because functions
such as news media facilities and potentially first family recreation
space would be moved.
The development under West Executive Avenue would require
the removal of many of the trees along the avenue-approximately
15 oaks and 2 saucer magnolias.
Constructing a staff circulation corridor along the north
side of the White House and redesigning the grounds maintenance
facility on the south grounds would have the same impacts as described
under the proposed plan. Two commemorative plantings and approximately
18 other trees on the north grounds would be at risk during construction.
In and adjacent to the existing maintenance facility on the south
grounds care would be taken to preserve the Children's Garden
and the bald cypresses (planted prior to 1900).
East Executive and Sherman Parks. A large area would
be excavated under East Executive Park and the south plaza of
the Treasury Building. The eastside parking and delivery facility
and the pedestrian corridor from the visitor center would put
approximately four large, mature willow oaks in Sherman Park at
risk and would require the removal of several willow oaks, Allegheny
serviceberry, and saucer magnolias from East Executive Park and
the west side of the Treasury Building.
Lafayette Park. Impacts on Lafayette Park would
be the same as described for the proposed plan. Development under
Jackson Place or Pennsylvania Avenue would not affect vegetation
within the park. Some street plantings along the west side of
Jackson Place could be removed or at risk during construction;
however, activities would be limited to the street if possible.
Ellipse. Constructing the White House visitor center
and museum underneath the northeast panel of the Ellipse would
require the temporary removal of approximately 21 trees (13 American
elms plus Norway maples, bald cypresses, American lindens or basswood,
and magnolias). The majority of elms line the northeast dog leg
and the adjacent section of the Ellipse Drive. As discussed for
the pro-posed plan, placing the entrance portals for the staff
parking facility at the southern end of the Ellipse would require
the permanent removal of approximately 13 elms along the north
and south sides of the Ellipse Drive near 16th Street. The underground
pedestrian corridor on the northwest end of the Ellipse would
require the temporary removal of between two and six American
elms and up to 25 other trees, depending on the construction method
(tunneling or cut-and-cover) and the location of the corridor
and its access points. Although trees that were temporarily removed
could be replaced after construction, the replacement stock would
be younger and much smaller than existing trees.
Dewatering activities could be required during the construction
of the visitor center and Ellipse parking facility. Soil moisture
would be monitored both during and after construction, and the
capability to water the trees would be required in the event moisture
sensors indicated a threatening decline in soil moisture.
Staging White House tours from the Ellipse visitor center
would eliminate current damage to both soils and turf on the surface
of the Ellipse caused by people assembling for tours. However,
soil compaction and turf damage would most likely continue to
occur in and around the Ellipse's northeast panel because of visitors
congregating in and around the new visitor center. Special events
would be rotated around the Ellipse to more evenly distribute
event-related soil and turf impacts. Realigning the existing steamline
would stop impacts on turf across the center of the Ellipse.
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Comprehensive Design Plan Continued