TIER 1 DRAFT ENVIRONMENTAL IMPACT STATEMENT

Construction 

Effects

8.

Tier 1 Draft EIS Page | 8-i

Table of Contents

8. CONSTRUCTION EFFECTS...........................................................................................................8-1

8.1 INTRODUCTION .................................................................................................................................8-1

8.2 CONSTRUCTION OVERVIEW.................................................................................................................8-1

8.2.1 Construction Types ...............................................................................................................8-1

8.2.2 Construction Impacts on Train Operations...........................................................................8-4

8.3 STATION CONSTRUCTION....................................................................................................................8-6

8.4 CONSTRUCTION EQUIPMENT ...............................................................................................................8-7

8.5 TYPICAL CONSTRUCTION SEQUENCING..................................................................................................8-8

8.6 CONSTRUCTION STAGING AREAS..........................................................................................................8-8

8.7 TEMPORARY CONSTRUCTION EFFECTS.................................................................................................8-10

8.8 POTENTIAL MITIGATION ...................................................................................................................8-13

8.9 SUBSEQUENT TIER 2 ANALYSIS...........................................................................................................8-14

Tables

TABLE 8-1: TYPICAL SEQUENCE OF CONSTRUCTION ACTIVITIES (ACTION ALTERNATIVES).........................................8-9

TABLE 8-2: EXAMPLES OF POTENTIAL CONSTRUCTION-RELATED EFFECTS ...........................................................8-10

Figures

FIGURE 8-1: PERCENTAGE OF ROUTE MILES BY CONSTRUCTION TYPE – WASHINGTON, D.C., TO BOSTON, MA...........8-2

FIGURE 8-2: TUNNEL BORING MACHINE...........................................................................................................8-7

FIGURE 8-3: GANTRY CRANE SYSTEM FOR AERIAL STRUCTURE OR MAJOR BRIDGE CONSTRUCTION............................8-7

FIGURE 8-4: TYPICAL NEW TRACK CONSTRUCTION MACHINE ..............................................................................8-8

Tier 1 Draft EIS Page | 8-1

8. Construction Effects

8.1 INTRODUCTION

This chapter describes the potential construction types and sequencing that would likely be required 

for constructing any of the Tier 1 Draft Environmental Impact Statement (Tier 1 Draft EIS) Action 

Alternatives. This chapter also presents a qualitative description of potential construction-related 

effects for each of the Tier 1 Draft EIS resource areas.

The Action Alternatives would involve improvements to the existing Northeast Corridor (NEC) and 

construction of significant new rail infrastructure—tunnels, bridges, embankments, new stations and 

ancillary roads and support facilities—across the NEC over an extended period. While this chapter 

describes potential construction-related effects of the Action Alternatives, it is not intended to 

describe the precise construction methods that would ultimately be used or to dictate or confine the 

construction process. Actual construction staging areas, construction methods, and materials would 

vary, depending on how Tier 2 projects are designed to be most cost effective within the guidelines 

of the oversight and funding entities, and within the requirements set forth in bid, contract, and 

construction documents. In addition, Tier 2 environmental studies would assess and document 

project-specific construction activities and their impact, as well as establish project permitting 

requirements and mitigation measures.

8.2 CONSTRUCTION OVERVIEW

8.2.1 Construction Types 

Detailed project design and construction information was not available for this Tier 1 Draft EIS 

analysis. Therefore, the Federal Railroad Administration (FRA) developed potential construction types 

based on available conceptual information for each Action Alternative. Six construction types

comprise the potential infrastructure associated with all of the New Track Construction (NTC) for the 

Action Alternatives: tunnel, trench, at-grade, embankment, aerial structure (bridges and viaducts),

and major bridge. The FRA considered existing NEC construction features, as well as land use, 

topographic and other environmental features, and cost in developing the construction types.

This section includes a general description of the potential construction types for any of the Action

Alternatives. Figure 8-1 describes the percentage of construction types by route distance for the 

existing NEC and each Action Alternative.
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Figure 8-1: Percentage of Route Miles by Construction Type – Washington, D.C., to 

Boston, MA

Source: NEC FUTURE team, 2015

* The percentage of route miles shown in Alternative 3 is the average route miles by construction type for all route options 

between Washington, D.C., and Boston.
8. Construction Effects

Tier 1 Draft EIS Page | 8-3

The following are characterizations of each of the construction types defined for the NTC of the Action 

Alternatives:

4 Tunnel construction lays tracks below the surface in a tunnel that is dug by a tunnel boring 

machine (TBM) or, in some instances, by cut-and-cover construction methods. Tunnel 

construction is used where the railroad right-of-way topography is submersed, where the 

topography is too steep for tracks designed for speeds of 160 to 220 mph to accomplish the 

grades 1 for climbing or braking, and in densely developed areas. While TBMs would be the 

assumed tunnel construction method, other methods such as cut-and-cover and drilling and 

blasting would be considered in Tier 2 project development.

4 Trench construction places the tracks in an open cut that is supported by retaining walls. Trench 

construction types were applied to a Representative Route in transition areas where the tunnel 

returns to at-grade or embankment.

4 At-grade construction is used where the topography is flat or locations where effects on 

environmental resources would be minimal. The at-grade construction type would generally be 

applied to the Representative Route where existing highway and roadway rights-of-way are grade 

separated on aerial structures above the tracks.

4 Embankment construction places the tracks atop an earthen embankment or retaining wall of 

varying height that slopes down to meet the existing grade. The embankment construction type 

generally would be applied to the Representative Route prior to and following an aerial structure. 

4 Aerial Structure construction elevates the tracks on infrastructure above the ground. The aerial 

structure construction type generally would be applied to the Representative Route in heavily 

urbanized areas where at-grade construction is not practical. Aerial structures would also be 

constructed at river crossings, wetland areas, valleys, or crossings over existing 

highways/roadways where vertical grade changes do not permit at-grade construction. Aerial 

structures consist of both bridges and viaducts, depending on topography and land use and 

presence of environmental resources.

4 Major Bridge construction is used over major water crossings where marine traffic requires 

adequate vertical clearance. 

Alternative 1 includes new construction within the existing NEC right-of-way to eliminate 

chokepoints. New construction outside the NEC right-of-way is confined to the Baltimore, MD, and 

New York City, metropolitan areas, and coastal Connecticut and Rhode Island. Alternative 2 includes 

new construction within the existing NEC right-of-way to remove speed restrictions, and provides 

construction of a new segment between New Haven and Hartford, CT, and Providence, RI. Alternative 

3 includes construction of new segments operating between Washington, D.C., and Boston, separate 

from the existing NEC to create a second spine, including new route options outside the NEC rightof-way between New York City, Hartford, and Boston. Chapter 7.15, Climate Change and Adaptation, 

 

1 Based on AREMA design criteria used on recent High-Speed Rail Studies, the desired maximum grade for highspeed track is 2.5% with 3.0% permitted in limited situations. The maximum length of continuous run at the 

maximum grade should be less than 10,000 feet. In order to comply with these criteria, the contours of the existing 

terrain may require tunneling or viaducts to meet these conditions.
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identifies known areas of the existing NEC where it is vulnerable to the effects of climate change,

including increased flooding from storm events and/or rising sea levels. Where the Action 

Alternatives propose improvements to the existing NEC in such areas, construction of the 

improvements will address those underlying vulnerabilities where practical.

All of the Action Alternatives would include approximately 2.5 miles of new tunnels in Baltimore, and 

approximately 3 miles of new tunnels crossing the Hudson River from New Jersey to New York. In 

Alternative 3, tunnels would account for approximately 18 percent of the construction types, of 

which one route option would include approximately 22 miles of tunnel across the Long Island Sound, 

and another route option would include approximately 55 miles of tunnel from New York City to 

Hartford via Central Connecticut.

Trenches would account for approximately 2 percent and 4 percent of the construction types in 

Alternative 1 and Alternative 2, respectively. In Alternative 3, approximately 6 percent of the 

construction types would consist of trenches, which would include approximately 30 miles of 

trenches in Nassau and Suffolk Counties for the route option that goes from New York to Hartford via 

Long Island.

At-grade construction would account for approximately 50 and 44 percent of the construction types 

for Alternative 1 and Alternative 2, respectively. This construction would be primarily within the 

existing NEC right-of-way, where the existing tracks are at-grade. For Alternative 3, at-grade 

construction would account for approximately 37 percent of the construction types, most of which is 

south of New York City. North of New York City, a new right-of-way would be added between New 

York City, Hartford, CT, and Boston, where at-grade construction is often infeasible because of 

topography and development.

Embankment construction would account for approximately 35 percent and 33 percent of Alternative 

1 and Alternative 2, respectively. Similar at-grade construction, this embankment construction would 

be primarily within the existing NEC right-of-way, where the existing tracks are on embankments. For 

Alternative 3, embankments would account for approximately 30 percent of the construction types, 

most of which would be south of New York City. North of New York City, a new right-of-way is added

between New York City, Hartford, CT, and Boston, where embankment construction would not be 

feasible because of topography and development except prior to and following a new aerial structure.

Aerial structures would account for a small percentage of all the Action Alternatives. This would 

include approximately 5 miles of aerial structures between Stamford and Westport in Fairfield 

County, CT, for all Action Alternatives.

Major bridges would account for less than 2 percent of the construction types for all of the Action 

Alternatives and would include major bridges over the Susquehanna River in Maryland, and Devon, 

Cos Cob, and Saugatuck Rivers in Fairfield County, CT. 

8.2.2 Construction Impacts on Train Operations

Implementation of dozens of infrastructure projects along an active rail corridor already operating at 

capacity will present severe challenges for a region that depends on reliable Intercity and Regional 
8. Construction Effects

Tier 1 Draft EIS Page | 8-5

train service. Not only would construction of individual projects be staged to minimize disruption to 

ongoing train operations, but the schedule for implementing multiple simultaneous projects across 

the NEC would be highly coordinated and integrated to provide required construction outages and 

resources (both materials and workers) where and when needed. Amtrak’s experience between 1994 

and 2000 in rebuilding and electrifying the New Haven–Boston segment of the NEC helps to 

demonstrate that complex, multi-dimensional project work across a large area of an active railroad 

can be successfully and safely undertaken with only minor impacts to ongoing train operations.

Nonetheless, the planning and staging of work to minimize adverse impacts to ongoing operations 

would be challenging and would require an unprecedented level of coordination among the various 

NEC rail operators. Even with the best of planning, likely adverse impacts could include the following:

4 Reduced service during portions of the day and night to lengthen periods of available outages for 

construction activities

4 Longer travel time, resulting from tracks being out of service and slower speeds on temporary 

infrastructure and around work zones

4 Reduced on-time performance and reliability resulting from specific project work, such as 

constructing infrastructure in between or adjacent to existing and live operating railroad tracks

4 Possible station closures and/or temporary stations to accommodate work at or around stations

4 Reduced parking at some stations 

4 Frequent changes to train schedules

Fortunately, while the scope of upgrades included in all of the Action Alternatives would be 

significant, the work required for some improvements would be undertaken sufficiently away from 

the existing tracks to minimize impacts to ongoing train operations. These upgrades would include a 

number of chokepoint projects, new bridges and tunnels, and new rail segments that would be 

constructed parallel to or along (or over) the existing NEC. These improvements would be designed 

specifically to minimize disruption to ongoing train operations.

Alternatives 2 and 3 include substantially new infrastructure built off the existing NEC. Alternative 2 

includes a new greenfield2 route option between New Haven and Hartford, CT, and Providence, RI,

to supplement the existing shoreline route. Alternative 3 includes construction of a new two-track 

second spine the entire length of the NEC. South of New York City, the new spine runs parallel to the 

existing NEC, with significant segments built within the existing right-of-way. North of New York City, 

the second spine would consist of greenfield construction off the existing NEC between New York 

City and Boston.

Construction in Alternative 3 off the existing NEC spine would provide some opportunity to minimize 

impacts on existing operations since once the new rail line is completed, some operations on the 

existing line would be shifted to the new route, freeing up the existing line for necessary construction 

activities. However, the extent of these potential benefits would be limited primarily to Intercity train 

 

2 Potential site for development—that is currently undeveloped or used as agricultural land—that lacks any 

existing structures.
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service north of New York City. For example, construction of a second spine segment between 

Hartford, CT, and New York City (via either Central Connecticut or Long Island) prior to upgrade of 

the existing NEC between those cities would help to minimize impacts to Intercity train service since 

Intercity trains would simply relocate to the new tracks once construction is completed.

However, Regional train service between New Haven, CT, and New York City would remain on the 

existing NEC while that segment of the NEC is improved in order to serve existing stations. South of 

New York City, substantial portions of the new second spine would be located on the existing NEC 

right-of-way, resulting in potential disruption to both Intercity and Regional trains. Similarly, while 

construction off the existing NEC may reduce some costs associated with staging of construction to 

minimize disruption to ongoing train operations, these savings would be limited since Regional train 

service would continue to operate on the existing NEC during construction north of New York City,

and construction within the right-of-way south of New York City would necessitate construction 

staging activities.

Regardless of which Action Alternative is selected, minimizing construction impacts on ongoing rail 

operations would be best planned and achieved by packaging projects into multiple phases of the 

selected alternative. Through such phases, individual projects would be timed to meet a number of 

important objectives. These would include optimizing the benefits across the NEC of complementary 

capacity and travel-time projects, balancing the demand on resources, and spacing projects to take 

advantage of construction outages and to minimize adverse impacts on ongoing train operations. The 

Service Development Plan will include a full phasing plan for the selected alternative that seeks to 

achieve these benefits. Chapter 10, Phasing and Implementation, includes a representative initial 

phase that could apply to any one of the Action Alternatives.

8.3 STATION CONSTRUCTION

Most new stations would be constructed where the Action Alternative involves new right-of-way off 

the existing NEC. In some cases, however, new stations would be added along the existing NEC.

Modifications to existing stations are proposed only on the existing NEC. New stations would be 

constructed concurrently with NTC. Modifications to existing stations would be completed in several 

phases of construction to maintain train service. These phases could involve construction of 

temporary run-around tracks while station platforms are expanded or modified. Once the 

modifications are completed, train service would be shifted back to the original track alignment. 

Construction of below-ground stations would typically employ open cut-and-cover construction, 

depending upon the depth of construction. While TBMs are assumed for construction of tunnels, cutand-cover construction is used for below-ground stations because of the extent of station spaces. 

Where the track is at-grade, on embankment or aerial structure, stations would be constructed to 

match the track elevation. 
8. Construction Effects

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8.4 CONSTRUCTION EQUIPMENT

The Action Alternatives would most likely use 

conventional construction techniques and 

equipment currently used in the Northeast 

and throughout the United States.

Typical equipment would include backhoe 

loaders, dump trucks, bulldozers, pile drivers, 

excavators, graders, compactors, bucket 

trucks, and smaller hand-operated devices 

such as welding equipment, rail cutters, and 

rail grinders. A few large-scale types of 

construction equipment may be required for 

more specialized construction associated 

with the Action Alternatives. For example, a 

TBM would likely be used for tunnel

construction (Figure 8-2). This machine 

consists of several large pieces of machinery 

that bore the tunnel, remove the earth and rock debris, and support the installation of walls.

For aerial construction and major bridges, a gantry crane system (Figure 8-3) would likely be used in 

the field to place prefabricated sections of viaduct and track. This system has been used for aerial 

construction of rail tracks in both Europe and China and has also been employed to construct highway 

bridges in the United States. Major bridges would also likely use tower cranes to lift and position 

heavy materials.

Figure 8-3: Gantry Crane System for Aerial Structure or Major Bridge Construction

Source: http://upload.wikimedia.org/wikipedia/commons/a/ab/Hada_high-speed_railway_under_const.JPG

Figure 8-2: Tunnel Boring Machine 

Source: http://www.livesoma.com/2012/02/27/central-subwayproject-update-soma-feb12/
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For at-grade, embankment, and trench 

construction, an NTC machine (Figure 8-4) would 

likely be used to construct the track and the track 

subballast, typically crushed stone below the 

tracks. An NTC can install continuously welded 

rail and concrete railroad ties, which would be 

required for the NEC.

8.5 TYPICAL CONSTRUCTION

SEQUENCING

This section provides information concerning 

typical construction sequencing for all of the 

Action Alternatives. Table 8-1 outlines 

construction activities in sequential order and 

describes key tasks.

8.6 CONSTRUCTION STAGING AREAS

Construction of the Action Alternatives would 

require construction staging areas, also referred 

to as “laydown areas.” These are areas and sites 

used to store materials and equipment, and to 

assemble construction materials. Work zones 

are those areas where the construction is 

occurring. Field offices for contractors and construction managers are usually situated in temporary 

job site trailers at staging areas or existing office space near the work areas. 

Construction staging/laydown in urban areas, where space is limited, is often located within the 

street right-of-way as permitted by local transportation departments. In some instances, the laydown 

areas can be set within the limits of vacant urban lots or within surface parking lots. In these 

instances, a payment would be needed to satisfy the needs of the private property owner in lieu of 

utilizing public street right-of-way.

In suburban or rural areas, construction/laydown areas are typically included in the right-of-way 

property requirements for the project. Staging/laydown areas vary in size with construction methods 

and facilities being constructed, but are typically 0.5 to 1 acre in size and are adjacent to the facility 

construction site. 

The specific location of construction staging/laydown areas would be identified in subsequent 

development of Tier 2 projects. Appendix A, Mapping Atlas, identifies the environmental resources 

within the Affected Environments for each Action Alternative. Consideration of these environmental 

resources would occur when identifying construction staging and access areas during subsequent 

project phases.

Figure 8-4: Typical New Track 

Construction Machine

Source: http://www.harscorail.com/equipment/trackconstruction-and-renewal/new-track-construction.html
8. Construction Effects

Tier 1 Draft EIS Page | 8-9

Table 8-1: Typical Sequence of Construction Activities (Action Alternatives)

Activity Tasks

Pre-Construction Survey ■ Perform geotechnical activities

■ Locate utilities

■ Establish rights-of-way and project control points and centerlines

■ Relocate survey monuments 

Site Preparation ■ Relocate utilities and clear and grub rights-of-way (demolition)

■ Widen streets

■ Establish detours and haul routes

■ Erect safety devices and mobilize special construction equipment

■ Prepare construction equipment yards and stockpile materials

■ Install monitoring instrumentation for tunneling

■ Implement ground improvements

■ Underpin existing building

■ Establish maintenance of traffic

Heavy Construction ■ Excavate and construct the tunnel portals, tunnels, and underground stations

■ Construct aerial structures, including foundation elements

■ Construct surface trackway

■ Reconstruct adjacent roadways and sidewalks

Medium Construction ■ Lay track 

■ Construct surface stations

■ Install drainage

■ Pave roadway and perform minor earthwork

Light Construction ■ Finish track alignment and surface

■ Install system elements (electrical signal and communications)

■ Install street lighting

■ Landscaping

■ Install signage and striping

■ Close detours

■ Clean-up and test system 

Pre-Revenue Service ■ Test communications

■ Implement signaling and ventilation systems

■ Train operators and maintenance personnel 

Source: NEC FUTURE team, 2015
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8.7 TEMPORARY CONSTRUCTION EFFECTS

Construction effects associated with any Action Alternative would likely be short term, depending on 

the duration of construction activities. The areas that would be most affected by construction 

activities would generally comprise the area immediately bordering the construction activities. 

However, in some cases, effects from construction activities could extend beyond the immediate area 

surrounding construction sites (e.g., dust carried by wind, or noise propagated over distances). 

Under the Action Alternatives, construction would include regular maintenance activities within the 

existing NEC right-of-way, as well as improvements that could occur outside of the existing NEC rightof-way. Project sponsors would be required to follow environmental requirements as specified in the 

necessary permits to minimize construction impacts.

Table 8-2 identifies examples of temporary construction effects from the Action Alternatives.

Table 8-2: Examples of Potential Construction-Related Effects

Resource Temporary Construction Effects

Transportation ■ Lengthened freight-rail travel times and, in turn, increased costs to freight-rail 

operators caused by reduced operating speeds through the construction zones. 

■ Impacts to local transit operations (e.g., light rail transit or bus), including lane 

closures, roadway closures, detours, and disruption of transit operations during 

peak and nonpeak times caused by construction within new rights-of-way off the 

existing NEC. 

■ Impacts to nearby local roadway operations, including changes in access, lane and 

roadway closures, detours, and disruption of traffic during peak and off-peak travel

times; loss of or decrease in parking areas and loading zones caused by

construction near stations.

Economic Effects ■ New employment opportunities associated with construction activities

■ Negative effects to some businesses from loss of parking and difficulty accessing 

businesses caused by roadway and sidewalk closures 

Land Cover ■ Easements required for construction activities, including storage of materials and 

equipment, access to construction areas, and other construction-related activities.

Agricultural Lands ■ Easements required for construction access and laydown areas

■ Effects to the use of and access to agricultural lands

■ Potential for erosion, sedimentation, and increase in flooding

■ Airborne dust from mobile and stationary construction-related equipment

■ Removal of or damage to vegetation (e.g., trees, shrubs, grass, etc.)
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Table 8-2: Examples of Potential Construction-Related Effects (continued)

Resource Temporary Construction Effects

Parklands ■ Disrupted access to park facility

■ Conversion of park property easements required for construction staging areas or 

access 

■ Loss of parking

■ Rerouting of trails during construction

■ Noise and vibration from construction equipment and vehicles

■ Potential for erosion, sedimentation, and increase in flooding

■ Changes to the visual environmental near construction sites caused by the 

introduction of construction workers, trucks, fencing, equipment, lighting, etc.

■ Airborne dust from mobile and stationary construction-related equipment

■ Removal of or damage to vegetation (e.g., trees, shrubs, grass, etc.)

Water Resources ■ Placement of fill material in designated wetland areas could cause soil erosion, 

sedimentation, or increased risk of contamination associated with presence of 

heavy equipment.

■ Use of water to support TBM operations.

■ Increases in runoff volume caused by the creation of impervious surface areas. 

■ Alteration of stream discharge caused by silt loading, increased siltation 

downstream of stream crossings, increased nutrient loading from runoff during 

construction, and increased potential for toxic substance release from construction 

vehicles or equipment.

Ecological Resources ■ Effects to wildlife from the elimination and/or fragmentation of forested habitat.

■ Construction noise and construction staging areas may displace some wildlife. 

■ Effects to Essential Fish Habitat could include habitat disturbance, and spawning 

could be affected by in-water construction work.

Hazardous Waste 

and Contaminated 

Material Sites

■ Excavation could encounter contaminated soil and groundwater.

■ Demolition activities could encounter asbestos-containing materials. 

■ Greatest potential for effects would be expected in areas of deep excavation and 

where dewatering would be required.

■ Release into the air of contaminants and hazardous materials located within the 

railroad right-of-way during construction and track maintenance/replacement 

activities.

Cultural Resources 

and Historic 

Properties

■ Construction could damage or alter cultural resources and historic properties. 

■ Fragile historic buildings and structures could be damaged by activities (e.g., pile 

driving) that cause vibration.

■ On the surface or below ground, cultural resources include archaeological sites and 

tribal resources that could be damaged or disturbed by grading activities and 

excavating natural soils for cuts, trenches, tunnel portals, ventilation shafts, 

footings for bridges and viaducts, and foundations for ancillary facilities. Depositing 

fill for embankments may also compress and damage the archaeological features. 

Visual and Aesthetic 

Resources

■ Presence and movement of construction machinery, equipment, building materials, 

construction access ways, construction cranes, fences and screens. 
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Table 8-2: Examples of Potential Construction-Related Effects (continued)

Resource Temporary Construction Effects

Environmental 

Justice

■ Transportation and environmental effects to both Environmental Justice (EJ) and 

non-EJ populations include increased levels of dust, noise, vibration, and vehicle 

emissions. Associated effects include temporary adjustments to vehicular and 

pedestrian traffic patterns and access, temporary loss or relocation of parking, and 

temporary visual impacts related to construction activities and stockpiling of 

materials and equipment.

■ Effects would be considered EJ impacts only if they disproportionately affected EJ 

populations. Evaluations of disproportionality would be undertaken as part of Tier 

2 evaluations.

Noise and Vibration ■ Vibration impacts from pile driving, heavy equipment usage, and tunneling.

■ Building damage could occur from construction-related vibration as a result of 

displacement (movement) of a building over time, resulting in structural damage.

Air Quality ■ Fugitive dust emissions from land clearing and grading operations can occur from 

excavation, hauling, dumping, spreading, grading, compaction, wind erosion, and 

traffic over unpaved areas. 

■ Increases in mobile source emissions both on and off the construction site from onand off-road construction equipment and vehicles.

■ Disruption to traffic during construction, such as reduction in roadway capacity and 

increased queue lengths, could result in short-term elevated concentrations of 

localized pollutants such as carbon monoxide and particulate matter.

■ Mobile source emissions from construction would occur as a result of operation of 

heavy-duty diesel and gasoline-powered construction equipment and operation of 

heavy-duty diesel trucks, and locomotives involved in transporting excavated 

material and delivering construction materials. 

■ Increase in CO2e emissions from construction activities that could be offset as the 

operational CO2e emissions reduce emissions from transportation.

Energy ■ Direct propulsion requirements, one-time, non-recoverable indirect energy 

expenditures would result from construction activities.

Safety ■ Limitations and vehicular and pedestrian access in certain areas to address public 

safety and to accommodate the variety of machinery, storage areas, and 

construction activities that would occur.

■

Source: NEC FUTURE team, 2015
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8.8 POTENTIAL MITIGATION

Construction of any Action Alternative could generate impacts to the natural and built environment.

During Tier 2 EIS evaluations, project sponsors would be required to develop project-specific 

measures to reduce and/or mitigate construction impacts. Examples of mitigation measures that 

could be employed include the following: 

4 Schedule construction activities that require lane or roadway closures during off-peak hours, 

where practicable.

4 Develop Maintenance of Traffic Plans.

4 Coordinate freight schedules and construction activities with railroads.

4 Locate staging areas on sites designated for permanent project use, such as parking lots and yard 

and maintenance facilities.

4 Coordinate with local business owners and provide notification of roadway disruptions and 

descriptions of alternative routes.

4 Maintain access to businesses during construction for customers and deliveries.

4 Use best management practices to minimize construction noise and vibration, including

alternative methods to avoid impact during pile driving where feasible; to limit nighttime 

construction and the use of backup alarms to the greatest extent possible; to use barriers to shield 

noisy construction equipment, and to specify construction truck routes that minimize noise 

exposure to sensitive community areas.

4 Implement dust control measures in accordance with state requirements, as well as use 

construction equipment that complies with U.S. Environmental Protection Agency’s emission 

standards. Possible dust and emission control measures include minimizing land disturbance;

covering trucks when hauling soil, stone and debris; using water trucks to minimize dust; using 

ultra-low sulfur diesel equipment; and equipping some construction equipment with emission 

control devices such as diesel particulate filters.

4 Coordinate with the public and agencies having jurisdiction over affected parks to develop 

appropriate minimization strategies during construction, including advanced public notice of 

planned activities and temporary changes in access.

4 Minimize disturbed areas and employ an Erosion and Sediment Control Plan to treat stormwater 

runoff.

4 Prevent the storage of fill and other materials in floodplains, to the extent practicable.

4 Dispose of and transport hazardous materials according to federal, state, and local guidelines to 

protect workers and the public.

4 Adhere to Construction Protection Plans for cultural resources and historic properties.

4 Provide construction barriers and fencing to secure construction sites and staging areas. 

4 Control access to construction sites through the use of construction fencing and barricades.

Maintenance of traffic plans would address motorist safety through construction work zones.

4 Coordinate with emergency services providers (e.g., police, fire, etc.) to minimize impacts and 

disruptions to emergency service routes near construction sites. 
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8.9 SUBSEQUENT TIER 2 ANALYSIS 

Subsequent planning and environmental compliance processes associated with Tier 2 projects would 

assess temporary construction-related effects to the natural and built environment. Tier 2 analysis 

would be based upon site-specific design and construction methods, as well as construction

scheduling and sequencing. Tier 2 evaluations would include field investigations and subsurface 

testing. Consultation with regulatory agencies regarding temporary construction effects and 

development of agreed-upon permit requirements/conditions would also be undertaken during 

Tier 2 evaluations.