**Programmatic Environmental Assessment:\
Nationwide Differential Global Positioning System**

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Prepared for:

Federal Highway Administration

In cooperation with:

U.S. Department of Transportation Office of the Secretary

U.S. Coast Guard

Federal Railroad Administration

December 1998

Prepared by:

John A. Chamberlain, Environmental Consultant

Patricia L. Burns, Program Director

Envirotechnical Program

SRI International

333 Ravenswood Avenue

Menlo Park, California 94025

Submitted to:

Mr. Ted Pugh, Vice-President

PB Farradyne, Incorporated

3200 Tower Oaks Boulevard

Rockville, Maryland 20852

#   {#section .heading0 .unnumbered}

# ABSTRACT {#abstract .heading0}

As required under the National Environmental Policy Act of 1969 (NEPA),
the Federal Highway Administration has prepared this Programmatic
Environmental Assessment (PEA) to evaluate the potential environmental
effects of a proposed U.S. Department of Transportation Nationwide
Differential Global Positioning System (NDGPS). This PEA evaluates
potential individual and cumulative impacts of the proposed action and
alternatives on environmental, land-use, and socioeconomic resource
areas. This PEA represents the first tier of environmental impact
analysis. Subsequent NEPA analyses tiered to this PEA may be prepared
when site-specific impacts cannot be avoided or mitigated as specified
herein.

To expand existing Differential Global Positioning System (DGPS)
capabilities nationwide, the installation of at least 67 additional
reference stations with low-frequency transmit antennas is required.
Three NDGPS deployment alternatives were considered. Alternative A would
consist of the conversion of 32 Ground Wave Emergency Network (GWEN)
relay nodes to NDGPS reference stations, transfer of GWEN equipment from
remaining GWEN relay nodes or spare GWEN equipment sets to 28 new NDGPS
site locations, and installation of 7 additional NDGPS sites using new
equipment, for a total of 67 NDGPS sites. Alternative B would consist of
installation of new equipment at 32 existing GWEN relay node sites and
at 35 new sites; each reference station would be physically similar to
those described under Alternative A. Alternative C would consist of
installation of 80 to 100 new reference station sites using equipment
similar to that at U.S. Coast Guard local area DGPS stations. The
environmental impact of the no-action alternative was also considered.

The potential for significant environmental impacts has been identified
for each deployment alternative, including the no-action alternative.
Under any of the proposed action alternatives, no significant
environmental impacts will result provided that specific site-selection
criteria and, if necessary, mitigation measures discussed in this PEA,
are applied to each site proposed for installation of an NDGPS reference
station. If, for some unforeseen reason, mitigation to reduce
potentially significant impacts cannot be implemented at a specific site
or a type of impact was not anticipated and addressed in this PEA, then
additional NEPA analysis and documentation will be prepared for
installation of an NDGPS facility at that specific site.

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# EXECUTIVE SUMMARY {#executive-summary .heading0}

The U.S. Department of Transportation (DOT) has been authorized under
Section 346 of Public Law 105-66 to select, install, and operate a
Nationwide Differential Global Positioning System (NDGPS) for public and
private applications. The proposed project would augment existing
satellite-based Standard Positioning Service (SPS) Global Positioning
System (GPS) range information with a differential correction broadcast
from a network of ground-based reference stations transmitting from
known positions. GPS users receiving both the differential correction
signal and the SPS range information will be able to more precisely
determine their location. Federal agencies that would implement the
proposed NDGPS service are the Federal Highway Administration (FHWA),
Federal Railroad Administration (FRA), DOT Office of the Secretary of
Transportation (OST), U.S. Coast Guard (USCG), U.S. Army Corps of
Engineers, U.S. Air Force (USAF), and the National Oceanic and
Atmospheric Administration. A draft Memorandum of Agreement (MOA) among
these agencies has been prepared for the establishment and operation of
the NDGPS (see Appendix A).

The purpose of an NDGPS network is to provide government and civilian
users with augmented radionavigation and positioning capabilities for
use in public safety applications. Other uses include a wide range of
transportation, scientific, and agricultural applications. Key uses
include public safety and traffic management and control functions for
vehicle and railroad transportation, inland waterway navigation,
notification of emergency conditions, natural resource and emergency
infrastructure mapping, and agricultural crop management.

The method for achieving an NDGPS service that best meets user
requirements for accuracy, availability, and reliability is the
expansion of the existing USCG local area Differential Global
Positioning System (DGPS) network of reference stations. The existing
system provides DGPS coverage to the Atlantic and Pacific Ocean coastal
regions, the Gulf coast, the Great Lakes region, and major inland
waterways. Under the preferred alternative, system expansion would
utilize existing Ground Wave Emergency Network (GWEN) relay-node sites
and equipment. These relay nodes consist of low and medium frequency
transmission antennas and associated equipment that have been
decommissioned by the USAF, Air Combat Command. In addition to the reuse
of selected GWEN sites, new site locations will be acquired to provide a
nationwide network of differential correction broadcasts. Under Phase I
of the proposed expansion, at least one reference station would provide
a usable NDGPS transmission to a GPS user located anywhere in the
continental U.S. and portions of Alaska by the year 2000. Under Phase
II, differential corrections from at least two reference stations (dual
coverage) would be available anywhere in the continental U.S. by 2002.

The FHWA is the lead agency, and the USCG, FRA, and OST are cooperating
agencies in the implementation of the National Environmental Policy Act
of 1969 (NEPA) requirements for the NDGPS program. A draft MOA among
these agencies has been prepared for compliance with NEPA (see Appendix
B). This draft Programmatic Environmental Assessment (PEA) provides a
basis for the FHWA and the cooperating agencies to determine whether a
Programmatic Environmental Impact Statement (PEIS) is required or if a
Finding of No Significant Impact (FONSI) is appropriate for
implementation of the proposed or alternative actions. This draft PEA
analyzes the potential for significant environmental effects in the
following issue areas: geology and soils, water quality, ecologically
sensitive areas, air quality, noise, visual resources, flora and fauna,
cultural resources, recreation, land use, hazardous materials,
socioeconomics, environmental justice, and radiofrequency (RF)
environment and human exposure. Reference station operation and
maintenance are also considered during the 15-year life of NDGPS, as are
actions that occur during decommissioning. Comments on the December 1998
draft PEA will be solicited from federal, state, and local agencies and
the public, and addressed in a final PEA.

Several technologies used in combination are required for NDGPS. All the
technology combinations considered for suitable NDGPS service to
government and civilian users require expansion of existing USCG local
area DGPS. The existing USCG service provides single coverage to
approximately 45 percent of the continental U.S. For nationwide service,
the deployment of NDGPS reference stations via any one of three
alternatives was considered. Alternative A consists of conversion of 32
GWEN sites to NDGPS reference station use and the transfer of GWEN
equipment from remaining GWEN sites to, or the installation of spare
GWEN equipment sets at, 28 new NDGPS site locations. Seven additional
sites would receive similar new equipment, for a total of 67 NDGPS
reference stations. Transmit antennas would use 299 ft-tall guyed towers
and operate at an effective radiated power (ERP) of no more than 500 W.
Alternative B would require installation of new equipment at 32 existing
GWEN relay node sites as well as at 35 new sites. The resulting NDGPS
reference stations would be physically similar to the reference stations
of Alternative A. Alternative C would utilize all new sites and
equipment similar to existing USCG local area DGPS stations. The
Alternative C reference stations would utilize either 90 ft- or 120
ft-tall towers and operate at an ERP of no more than 170 W.
Approximately 80 to 100 reference stations would be required for an
NDGPS service under this alternative. This PEA also examines the
environmental impact of not implementing NDGPS under the no-action
alternative. The affected environment under each action alternative
includes the use of existing GWEN sites and equipment and/or the use of
other minimally developed or undeveloped 11-acre land parcels located
principally in the interior portions of the continental U.S. and Alaska.
Sites will typically be on level ground and away from tall objects or
structures.

During the selection of sites for NDGPS reference stations, the FHWA and
cooperating agencies are committed to avoiding potentially significant
environmental impacts by applying environmental siting criteria and,
where necessary, the use of appropriate mitigation measures. If
necessary, the following methods will be applied in sequence to mitigate
impacts:

-   Avoid the impact altogether by not undertaking the action or parts
    of the action

-   Minimize the impact by limiting the degree or magnitude of the
    action and its implementation

-   Rectify the impact by repairing, rehabilitating, or restoring the
    affected environment

-   Reduce or eliminate the impact over time by preservation and
    maintenance operations during the life of the action

-   Compensate for the impact by replacing or providing substitute
    resources or environments.

The FHWA and cooperating agencies will consult with key regulatory
agencies and apply environmental site-selection criteria to avoid
potentially significant impacts at new (non-GWEN) sites selected for
NDGPS. If a potentially significant environmental impact is unavoidable
during the selection of sites for NDGPS reference stations, specific
mitigation measures will be implemented to decrease the impact to a less
than significant level. If environmental site-selection criteria and
specific mitigation measures identified in Table 11 (section 7) are
implemented during the selection of NDGPS reference station locations,
no significant environmental impacts will occur under any of the
proposed action alternatives. If, for some unforeseen reason, planned
mitigation measures for potentially significant impacts cannot be
implemented at a specific site, or a site-specific impact is encountered
that was not anticipated and addressed in this PEA, then additional
appropriate NEPA analysis and documentation will be prepared by the FHWA
for that specific reference station.

For each alternative, electromagnetic interference (EMI) with nearby
Federal Aviation Administration radiobeacons operating in the same
frequency band may occur. This EMI impact, however, can be mitigated by
reassigning the operating frequency of one of the interfering sources of
RF or, in some cases, altering the ERP.

Implementation of the mitigation measures identified in this PEA,
including agency consultation and acquisition of required permits,
should prevent significant environmental impacts from conversion of GWEN
relay nodes to NDGPS reference stations.

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# TABLE OF CONTENTS {#table-of-contents .heading0}

> ABSTRACT iii
>
> EXECUTIVE SUMMARY v
>
> list of figures xii
>
> list of TABLES xiii
>
> list of abbreviations xv
>
> 1 INTRODUCTION [1](#introduction)
>
> 1.1 function of NDGPS [1](#function-of-ndgps)
>
> 1.2 department of transportation authorization
> [1](#department-of-transportation-authorization)
>
> 1.3 selectiNg an ndgps architecture
> [4](#selecting-an-ndgps-architecture)
>
> 1.4 NEPA POLICY and Environmental Documentation
> [6](#nepa-policy-and-environmental-documentation)
>
> 2 purpose and need [9](#purpose-and-need)
>
> 3 DESCRIPTION OF PROPOSED ACTION [11](#description-of-proposed-action)
>
> 3.1 Proposed NDGPS Service [11](#proposed-ndgps-service)
>
> 3.2 Existing USCG DGPS Service [11](#existing-uscg-dgps-service)
>
> 3.3 Proposed Reuse of GWEN Facilities and Equipment and installation
> of new NDGPS reference stations
> [12](#proposed-reuse-of-gwen-facilities-and-equipment-and-installation-of-new-ndgps-reference-stations)
>
> 3.4 Description of Typical NDGPS Reference Station
> [29](#description-of-typical-ndgps-reference-station)
>
> 3.5 NDGPS Reference Station Maintenance
> [32](#ndgps-reference-station-maintenance)
>
> 3.6 USCG Control Station [32](#uscg-control-station)
>
> 4 alternatives [33](#alternatives)
>
> 4.1 reasonable alternative TECHNOLOGies
> [33](#reasonable-alternative-technologies)
>
> 4.2 Description of alternatives ANALYZED IN DETAIL
> [36](#description-of-alternatives-analyzed-in-detail)
>
> 5 affected environment [41](#affected-environment)
>
> 5.1 Geology AND SOILs [41](#geology-and-soils)
>
> 5.2 water quality [42](#water-quality)
>
> 5.3 ecologically sensitive areas [44](#ecologically-sensitive-areas)
>
> 5.4 air quality [45](#air-quality)
>
> 5.5 noise [46](#noise)
>
> 5.6 Visual Resources [47](#visual-resources)
>
> 5.7 flora and fauna [50](#flora-and-fauna)
>
> 5.8 cultural resources [51](#cultural-resources)
>
> 5.9 recreation [53](#recreation)
>
> 5.10 land use [54](#land-use)
>
> 5.11 socioeconomics and Environmental justice
> [57](#socioeconomics-and-environmental-justice)
>
> 5.12 energy [58](#energy)
>
> 5.13 HAZARDOUS MATERIALS [58](#hazardous-materials)
>
> 5.14 Radiofrequency Environment and Human Exposure
> [60](#radiofrequency-environment-and-human-exposure)
>
> 6 environmental consequences [63](#environmental-consequences)
>
> 6.1 Geology [64](#geology)
>
> 6.2 water quality [65](#water-quality-1)
>
> 6.3 ecologically sensitive areas [68](#ecologically-sensitive-areas-1)
>
> 6.4 air quality [69](#air-quality-1)
>
> 6.5 noise [71](#noise-1)
>
> 6.6 Visual Resources [72](#visual-resources-1)
>
> 6.7 flora and fauna [75](#flora-and-fauna-1)
>
> 6.8 cultural resources [78](#cultural-resources-1)
>
> 6.9 recreation [81](#recreation-1)
>
> 6.10 land use [84](#land-use-1)
>
> 6.11 socioeconomics and environmental justice
> [86](#socioeconomics-and-environmental-justice-1)
>
> 6.12 energy [90](#energy-1)
>
> 6.13 Hazardous materials [91](#hazardous-materials-1)
>
> 6.14 radiofrequency radiation environment and human
>
> exposure
> [95](#radiofrequency-radiation-environment-and-human-exposure)
>
> 6.15 irreversible or irretrievable commitment of resources
> [99](#irreversible-or-irretrievable-commitment-of-resources)
>
> 7 mitigation measures [101](#mitigation-measures)
>
> 8 COnclusion [105](#conclusion)
>
> 9 references [107](#references)
>
> 10 List of preparers [111](#list-of-preparers)
>
> APPENDICES
>
> A DRAFT MEMORANDUM OF AGREEMENT for the establishment and operation of
> the nationwide differential global positioning system A-1
>
> B DRAFT MEMORANDUM OF AGREEMENT for compliance with the national
> environmental policy act for the establishment of the nationwide
> differential global positioning system\
> service B-1
>
> C GWEN RELAY NODES AND OTHER (NON-GWEN) SITES PROPOSED\
> FOR NDGPS USE C-[1](#for-ndgps-use)
>
> D distribution list for the notice of availability---ndgps draft
> programmatic environmental assessment
> D-[1](#distribution-list-for-the-notice-of-availabilityndgps-draft-programmatic-environmental-assessment)

# LIST OF FIGURES {#list-of-figures .heading0}

Figure 1 Space-based GPS Satellite Constellation 2

Figure 2 GPS Satellites Within NDGPS Reference Station Orbital Plane 2

Figure 3 Depiction of GPS Satellite Range and NDGPS Correction Signal
Broadcasts 3

Figure 4 Locations of Existing USCG Local Area DGPS Reference Stations
(CONUS) 13

Figure 5 Locations of Existing USCG Local Area DGPS Reference Stations
(Alaska) 14

Figure 6 Existing USCG Local Area DGPS Coverage (CONUS) 15

Figure 7 Existing USCG Local Area DGPS Coverage (Alaska) 16

Figure 8 Existing USCG DGPS and Proposed NDGPS Reference Station
Locations---Phase I CONUS (Preferred Action Alternative) 17

Figure 9 Existing USCG DGPS and Proposed NDGPS Reference Station
Locations---Phase I Alaska (Preferred Action Alternative) 18

Figure 10 Estimated Phase I NDGPS Coverage (CONUS) 19

Figure 11 Estimated Phase I NDGPS Coverage (Alaska) 20

Figure 12 Existing USCG DGPS and Proposed NDGPS Reference Station
Locations---Phase I and II CONUS 21

Figure 13 Existing USCG DGPS and Proposed NDGPS Reference Station
Locations---Phase I and II Alaska 22

Figure 14 Estimated Phase II NDGPS Coverage and Remaining (Shaded) Phase
I Coverage (CONUS) 23

Figure 15 Estimated Phase II NDGPS Coverage (Alaska) Including Both
Single and Dual Coverage Areas 24

Figure 16 Typical GWEN Relay Node 25

Figure 17 Plan View of Typical GWEN Relay Node 26

Figure 18 Photograph: Representative GWEN Relay Node (Savannah Beach,
Georgia) 27

Figure 19 Photograph: GWEN Antenna Tuning Unit Shelter and Security
Fence (Savannah Beach, Georgia) 28

Figure 20 Photograph: GWEN Equipment Area (with 30 ft Tall UHF Antenna,
Radio Equipment and Backup Power Group Shelters) 28

Figure 21 Conceptual NDGPS Reference Station Layout 30

Figure 22 Proposed NDGPS Equipment Shelter for Reference Stations Not
Using GWEN Equipment 31

# LIST OF TABLES {#list-of-tables .heading0}

Table 1 NDGPS Participants and Responsibilities 4

Table 2 Proposed or Developed Augmented GPS Systems 34

Table 3 System Architectures Versus User Requirements 35

Table 4 Number of Properties to be Acquired Under Each Alternative at
Full Buildout 38

Table 5 Freshwater Toxics Criteria for Dissolved Copper 43

Table 6 BLM VRM Classifications 49

Table 7 VMC Ratings for Various Conditions 74

Table 8 Summary of GWEN Environmental Baseline Surveys 92

Table 9 Safety Standards for Human Exposure to RFR at an Operating
Frequency of 300 kHz 96

Table 10 Ground Level Electric and Magnetic Fields at a Typical NDGPS
Reference Station 96

Table 11 Environmental Siting Criteria and Consultation and Mitigation
Measures for NDGPS Facilities at new Locations and GWEN Locations 102

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list of abbreviations

  ---------------- ------------------------------------------------------
  µg               microgram

  A                ampere

  ACHP             Advisory Council on Historic Preservation

  ACTS             Advanced Communications Technology Satellite

  AGL              above ground level

  AM               amplitude modulated

  A/m              amperes per meter

  ANSI             American National Standards Institute

  AST              aboveground storage tank

  ASTM             American Society of Testing and Materials

  ATU              antenna tuning unit

  BLM              Bureau of Land Management

  BOR              Bureau of Reclamation

  BUPG             backup power group

  CAT              Category of Aircraft

  CCC              Criteria Continuous Concentration

  CE               Categorical Exclusion

  CEQ              Council on Environmental Quality

  CFR              Code of Federal Regulations

  CMC              Criteria Maximum Concentration

  CO               carbon monoxide

  CONUS            Continental United States

  CORS             Continuously Operating Reference Station

  CZMA             Coastal Zone Management Act

  CZMP             Coastal Zone Management Plan

  dB               decibel

  DGPS             Differential Global Positioning System

  DOC              Department of Commerce

  DOD              Department of Defense

  DOT              Department of Transportation

  EA               Environmental Assessment

  EDDA             environmental due diligence assessment

  EIS              Environmental Impact Statement

  EMC              electromagnetic compatibility

  EMD              Electronics Maintenance Detachment

  EMI              Electromagnetic interference

  EPA              Environmental Protection Agency

  ER               en route

  ERP              effective radiated power

  FAA              Federal Aviation Administration

  FCC              Federal Communications Commission

  FEIS             Final Environmental Impact Statement

  FEMA             Federal Emergency Management Agency

  FHWA             Federal Highway Administration

  FM               frequency modulation

  FONSI            Finding of No Significant Impact

  FPPA             Farmland Protection Policy Act

  FRA              Federal Railroad Administration

  g                gram

  GLONASS          Global Orbiting Navigation Satellite System

  GPS              Global Positioning System

  GWEN             Ground Wave Emergency Network

  HC               hydrocarbon

  IEEE             Institute of Electrical and Electronic Engineers

  INS              Inertial Navigational System

  IOC              Initial Operational Capability

  IRPA             International Radiation Protection Association

  ITS              Intelligent Transportation System

  kHz              kilohertz

  km               kilometer

  kW               kilowatt

  l                liter

  LF               Low frequency

  m                meter

  MBTA             Migratory Bird Treaty Act

  mg               milligram

  MF               medium frequency

  mi               statute mile

  MOA              Memorandum of Agreement

  MPE              maximum permissible exposure

  NAAQS            National Ambient Air Quality Standards

  NCSHPO           National Conference of State Historic Preservation
                   Officers

  NDGPS            Nationwide Differential Global Positioning System

  NEPA             National Environmental Policy Act

  NHPA             National Historic Preservation Act

  NO~x~            oxides of nitrogen

  NO~2~            nitrogen dioxide

  NOAA             National Oceanic and Atmospheric Administration

  NPS              National Park Service

  NRC              National Research Council

  NRCS             Natural Resource Conservation Service

  NRHP             National Register of Historic Places

  NSTC             National Science and Technology Committee

  NTIA             National Telecommunications and Information
                   Administration

  O~3~             ozone

  OMB              Office of Management and Budget

  OST              Office of the Secretary of Transportation

  Pb               lead

  PCB              polychlorinated biphenyl

  PDD              Presidential Decision Directive

  PEA              Programmatic Environmental Assessment

  PEIS             Programmatic Environmental Impact Statement

  PIT              Policy and Implementation Team

  PL               Public Law

  ppm              parts per million

  PPS              Precise Positioning Service

  PSD              Prevention of Significant Deterioration

  RF               radiofrequency

  RFR              radiofrequency radiation

  SHPO             State Historic Preservation Office

  SO~2~            sulphur dioxide

  SPCC             Spill Prevention, Control, and Countermeasure

  SPS              Standard Positioning Service

  TEA-21           Transportation Equity Act for the 21^st^ Century

  TSP              total suspended particulates

  UHF              ultra high frequency

  U.S.             United States

  USACE            U.S. Army Corps of Engineers

  USAF             U.S. Air Force

  USCG             U.S. Coast Guard

  USDA             U.S. Department of Agriculture

  USFS             U.S. Forest Service

  USFWS            U.S. Fish and Wildlife Service

  USGS             U.S. Geological Survey

  V                volt

  VLF              very low frequency

  VMC              Visual Modification Class

  VRM              Visual Resource Management

  W                watt

  WAAS             Wide Area Augmentation System

  WAS              Wide Area System
  ---------------- ------------------------------------------------------

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# INTRODUCTION

## function of NDGPS

Global Positioning System (GPS) satellite signals can be received around
the world. The existing GPS uses 24 satellites to provide radio signals
which allow persons on the ground, in flight, or at sea to determine
their location (see Figure 1). GPS receivers, which are commercially
available from a number of sources, receive the radio signals
transmitted by these satellites and calculate the location of the
receiver in widely used coordinate systems, such as latitude and
longitude. Signals from at least four satellites should be received to
obtain an accurate location estimate (see Figure 2). Two types of
service quality are available, and the accuracy with which the
receiver's location can be calculated depends on the type of service
received. Precise Positioning Service (PPS) is available only to the
U.S. military and other authorized users for national security reasons.
It provides a horizontal accuracy of 22 m and a vertical accuracy of
27.2 m. Standard Positioning Service (SPS) is available to all members
of the public and provides a horizontal accuracy of 100 m and a vertical
accuracy of 156 m.

The Nationwide Differential Global Positioning System (NDGPS) will
augment the existing satellite system with ground-based radio
transmitters, known as reference stations. The reference stations will
broadcast a signal from a transmitter located at a known fixed location
on the ground. Users who receive the ground-based signal in addition to
the normal satellite signals will be able to determine their position
with an accuracy of 1 to 3 m (see Figure 3). While the existing U.S.
Coast Guard (USCG) local area Differential Global Positioning System
(DGPS) provides this service near coastal areas and navigable waterways,
NDGPS would serve the remaining 55 percent of the continental U.S.
(CONUS) and Alaska. Under Phase I, NDGPS would provide single coverage
(an NDGPS signal from at least one reference station reaching a GPS user
anywhere in the CONUS and Alaska). After Phase II installation, the
proposed NDGPS will provide dual coverage (an NDGPS signal from at least
two reference stations reaching a GPS user anywhere in the CONUS and
Alaska) with 99.999 percent availability. In addition, the reference
stations will monitor the locations of satellites and notify system
operators if a satellite is not performing within specified tolerances.
Thus, the NDGPS augmentation will also help to ensure the reliability of
the satellite radio signals.

## department of transportation authorization

Under Section 346 of Public Law (PL) 105-66, the U.S. Department of
Transportation (DOT) is authorized to design, install, and operate an
NDGPS service (see Appendix A). The law directs the Secretary of
Transportation to investigate improvements, to develop standards, to
sponsor new applications, and to continually upgrade NDGPS to meet the
needs of federal, state,

Figure 1 Space-based GPS Satellite Constellation

Figure 2 GPS Satellites Within NDGPS Reference Station Orbital Plane

Figure 3 Depiction of GPS Satellite Range and NDGPS Correction Signal
Broadcasts

and local governments and the general public. The agencies within DOT
and their responsibilities with respect to the proposed NDGPS are as
shown in Table 1.

+--------------------------------+-------------------------------------+
| Table 1\                       |                                     |
| NDGPS Participants and         |                                     |
| Responsibilities               |                                     |
+--------------------------------+-------------------------------------+
| Agency                         | Responsibility                      |
+--------------------------------+-------------------------------------+
| > Office of the Secretary of   | > Interagency coordination and      |
| > Transportation (OST)         | > policy guidance                   |
+--------------------------------+-------------------------------------+
| > Federal Railroad             | > System sponsor (funding)          |
| > Administration (FRA)         |                                     |
+--------------------------------+-------------------------------------+
| > Federal Highway              | > Network design, radio signal      |
| > Administration (FHWA)        | > coverage verification,            |
|                                | > environmental review              |
+--------------------------------+-------------------------------------+
| > U.S. Coast Guard (USCG)      | > Installation, operation,          |
|                                | > maintenance, and long-term system |
|                                | > improvement                       |
+--------------------------------+-------------------------------------+
| > U.S. Army Corps of Engineers | > Real estate services and          |
| > (USACE)                      | > management                        |
+--------------------------------+-------------------------------------+
| > U.S. Air Force (USAF)        | > Transfer of Ground Wave Emergency |
|                                | > Network (GWEN) property and       |
|                                | > equipment for NDGPS use           |
+--------------------------------+-------------------------------------+
| > National Oceanic and         | > Establish and maintain            |
| > Atmospheric Administration   | > coordinates for each reference    |
| > (NOAA)                       | > station, integrate NDGPS into the |
|                                | > Continuously Operating Reference  |
|                                | > Station (CORS) system, and        |
|                                | > coordinate the use of NDGPS in    |
|                                | > the Integrated Precipitable Water |
|                                | > Vapor System.                     |
+--------------------------------+-------------------------------------+

A draft Memorandum of Agreement (MOA) among the agencies listed in Table
1 identifies the respective role of each agency in the implementation of
NDGPS (see Appendix A). A number of other federal agencies will be major
users of NDGPS service. These include the Department of Interior
(National Park Service \[NPS\] and Bureau of Land Management \[BLM\]),
the Department of Energy, the Department of Justice, the Department of
Commerce (DOC), the Department of Agriculture, and the Environmental
Protection Agency (EPA). Use of NDGPS service by many local and state
governmental agencies is also anticipated.

This Programmatic Environmental Assessment (PEA) evaluates the
anticipated environmental consequences of the DOT effort to deploy
reference stations nationwide that will provide DGPS service for both
government and commercial applications. When fully implemented, this
service will provide accurate navigation and positioning information
across the nation, promoting safety and efficiency in transportation and
other fields.

## selectiNg an ndgps architecture

The need to select and implement a single radionavigation system that
meets diverse user requirements was recognized in the early 1990s. In
December 1993, the U.S. Department of Defense (DOD) and DOT published a
Joint Task Force report entitled *The Global Positioning System:
Management and Operation of a Dual Use System* (Joint DOD/DOT Task
Force, 1993). The report considered both military and civilian
requirements for accuracy, reliability, coverage, integrity, and cost
while eliminating unnecessary duplication of facilities and services.
The satellite-based GPS was identified as the system most capable of
meeting the full range of military and civilian navigation and
positioning requirements.

During the early 1990s, several government agencies were independently
planning to develop an augmented GPS service for various uses. The Joint
Task Force report concluded that a study of all augmentation
alternatives was required to develop an optimum integrated system. In
December 1994, a study entitled *A Technical Report to the Secretary of
Transportation on a National Approach to Augmented GPS Services* was
published (DOC National Telecommunications and Information
Administration \[NTIA\], 1994). The study evaluated the capabilities of
the various augmented GPS technologies and determined the optimum
technology mix for DGPS.

Nineteen existing and proposed federal, private, and foreign augmented
GPS technologies were considered in the Joint Task Force report. Of
these, seven were identified as being technically feasible and
potentially capable of meeting user requirements in the near future
(however, no single existing or planned augmented GPS technology was
found to be capable of meeting all user requirements). From these, six
potential composite system architectures (i.e., combinations of feasible
technologies) were proposed to satisfy as many user requirements as
possible. The baseline architecture is the existing USCG local area
DGPS, which does not provide nationwide coverage. All of the other
architectures considered would also involve the expansion of the
existing USCG local area DGPS service to a nationwide network.

Expansion of the USCG system required additional analysis to ensure it
was technically feasible. The proposed expansion would provide service
to the 55 percent of the contiguous U.S. and parts of Alaska not
currently covered by the existing USCG local area DGPS system. Of
principal concerns were the availability of frequency spectrum, and the
number and distribution of reference stations. A frequency analysis was
performed to design a nationwide network of reference stations that
would minimize the potential for electromagnetic interference (Lemmon
and Ketchum, 1998).

A Presidential Decision Directive (PDD) dated March 28, 1996, was issued
based on a National Science and Technology Committee (NSTC) document
identified as NSTC-6. It provided federal agencies with specific goals
and direction for further implementation of an NDGPS service. The goals
expressed in the PDD include: strengthen national security, integrate
GPS into nonmilitary applications, encourage private sector investment
in GPS, and promote safety and efficiency in transportation and other
disciplines. The PDD directed the DOT to serve as the lead agency within
the U.S. Government for all federal civil GPS matters and to develop and
implement U.S. Government augmentations to the basic GPS technology for
transportation applications.

In January 1997, the DOT formed an interagency NDGPS Executive Steering
Group consisting of senior management from each participating agency,
and an NDGPS Policy and Implementation Team (PIT) to lead the
implementation of the nationwide system. The NDGPS PIT documented the
requirements of many federal and state agencies, evaluated alternative
methods of providing differential corrections, documented benefits, and
developed a cost benefit analysis in accordance with the Office of
Management and Budget (OMB) Circular A‑94. This work is documented in
the team's *Nationwide DGPS Report* (NDGPS PIT, 1998). Seventeen
Executive Steering Group members and 27 PIT members from the public and
private sectors contributed to the formulation of the NDGPS report. Many
public safety applications are identified in the report, including
saving lives on the railroads and highways.

## NEPA POLICY and Environmental Documentation

The NDGPS MOA identifies the FHWA as the lead federal agency, as defined
in 40 *Code of Federal Regulations* (CFR) 1501.5, for NDGPS program
compliance with the National Environmental Policy Act (NEPA). As allowed
by 40 CFR 1505.1(a), the parties to the MOA agree that FHWA NEPA
regulations (23 CFR 771) will provide primary direction for
environmental impact analysis and procedural compliance with NEPA. A
separate MOA for the implementation of NEPA has been prepared which
identifies the roles of the USCG, FRA, and OST as cooperating agencies
in this process (see Appendix B).

During project planning and the preparation of NEPA documents, the FHWA
has followed technical advisory T6640.8A, "Guidance for Preparing and
Processing Environmental and Section 4(f) Documents," dated October 30,
1987, and the FHWA's Environmental Policy Statement, first issued in
1990 and revised in 1994. Based on this policy, the FHWA is committed to
incorporating environmental stewardship into its planning procedures,
project development, and decision making. Social, economic, and
environmental goals are considered equally with engineering, safety, and
mobility issues in reaching project decisions. This includes the
preparation of an NDGPS PEA that captures and fully describes options to
avoid, minimize, and mitigate adverse impacts and, where possible,
enhance the natural and human environment. The FHWA's policy, ensuring
that environmental commitments made during planning and project
development and identified in NEPA documents, will be implemented during
facility site selection, construction, maintenance, and operation.

This draft PEA analyzes the potential for the proposed installation and
operation of the NDGPS to result in significant effects on the quality
of the environment. The scope of the analysis is consistent with
requirements set forth in FHWA regulations for environmental assessments
(23 CFR 771.119). When necessary, measures to mitigate adverse impacts
(both significant and nonsignificant) have been incorporated into the
proposed action, per FHWA policy described in 23 CFR 771.105(d). As
required under NEPA regulations, the effectiveness and possible
environmental effects of a range of alternative actions and the
no-action alternative are analyzed. This document also specifies the use
of environmental site-selection criteria and planned mitigation measures
to be used to avoid or reduce potentially significant impacts that may
occur during implementation of NDGPS. Where local conditions at proposed
NDGPS reference stations warrant, the government intends to conduct
follow-up environmental analyses at a site-specific level. Those
analyses may include additional NEPA impact analysis and documentation.

The scope of this PEA focuses on the installation, operation, and
eventual decommissioning of reference stations to supplement the
existing USCG local area DGPS. Installation and operation of existing
USCG local area DGPS reference stations are not included in this
analysis. The FHWA is the lead agency under NEPA, however, other
participating agencies have been given the opportunity to review this
PEA. Copies of the draft PEA will be made available to the public and
government agencies for comment during a 30-day period. For areas where
considerable local concern is expressed, the FHWA may conduct a public
meeting to describe the proposed project and discuss any project-related
concerns.

The general size and layout of existing equipment and infrastructure at
USAF GWEN sites are very similar to that proposed for NDGPS reference
stations. Both the existing GWEN stations and NDGPS reference stations
use the low frequency (LF) portion (\~300 kHz) of the radiofrequency
(RF) spectrum. Much of the analysis presented in the GWEN Final
Environmental Impact Statement (EIS) applies to the FHWA proposal to
install DGPS service at GWEN sites or use identical or similar equipment
at new sites. Portions of this PEA are based on applicable information
contained in the GWEN Final EIS (USAF, 1987). However, that information
has been updated to account for changes in regulations and the physical
environment. The GWEN Final EIS may be obtained by contacting: HQ Air
Combat Command/CEVP, Langley Air Force Base, Virginia 23665.

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# purpose and need

The NDGPS is a proposed nationwide radionavigation system that would use
ground-based reference stations to broadcast radio signals for DGPS
users to obtain greater positioning accuracy than is possible using only
the existing satellite GPS signals. The proposed NDGPS would provide
positioning accuracy, availability, integrity, and coverage sufficient
to meet numerous government and civilian GPS navigation requirements,
and would represent a significant improvement over traditional
positioning technologies used in land and marine applications.

Current GPS assets are managed by the DOD. Neither of the available two
levels of GPS service, PPS and SPS, are sufficient to meet the existing
and anticipated needs of GPS users for nationwide navigation and
positioning.

The purpose of the proposed NDGPS is to provide government and civilian
users with augmented SPS radionavigation and positioning capabilities
through use of range-correction information broadcast by the reference
stations. This will enable greater position accuracy in public safety,
transportation, scientific, and agricultural applications.

An NDGPS is the most effective and efficient use of existing
technologies that will meet the navigation and positioning requirements
of land and marine GPS users. Under the preferred action alternative, an
economic benefit of \$10.4 billion is estimated (NDGPS PIT, 1998). A key
NDGPS land transportation need is to support the Intelligent
Transportation Systems (ITS) initiative under the Transportation Equity
Act for the 21^st^ Century (TEA-21). The ITS initiative will result in
development of programs in the areas of traffic management, traveler
information, vehicle control, public transportation, rural
transportation, and commercial vehicle operations.

An NDGPS is also needed to provide train location and speed information
to support public safety elements of advanced train control systems,
such as positive train control. This will permit dynamic supervision of
multiple trains, including positive train separation, when coupled with
input from railway sensors and data communication networks that manage
railroad traffic. These systems will increase train safety and improve
the operating efficiency of the railroad system saving over \$60 million
per year (Allen, 1998).

Currently, USCG local area DGPS reference stations serve a variety of
maritime navigation applications, including harbor, coastal, and ocean
navigation for vessels of all sizes. An NDGPS would increase the
reliability of these services and provide navigation reference points
for inland waterways not currently served by the existing local area
DGPS network.

Many other public safety applications that would benefit from an NDGPS
have been identified (NDGPS PIT, 1998). These include tracking law
enforcement assets, monitoring natural resources, monitoring groundwater
contamination, abating hazardous material contamination, and mapping
safety infrastructure. Agencies at all levels of government will use the
NDGPS to locate and track the movement of personnel and assets; to map
natural and man-made features of concern; to receive automatic
notification of accidents and emergencies; and to assist in emergency
response. These applications will provide considerable benefits by
enhancing public safety and fostering economic development.

#  DESCRIPTION OF PROPOSED ACTION

## Proposed NDGPS Service

Under the preferred action alternative, expansion of existing USCG local
area DGPS service to an NDGPS will require the following:

-   Acquiring or leasing 32 GWEN relay node sites

-   Acquiring 53 previously built and 6 spare GWEN equipment sets

-   Converting 32 GWEN relay nodes into NDGPS reference stations

-   Selecting candidate sites for NDGPS reference stations using
    technical and environmental siting criteria

-   Consulting with appropriate agencies regarding all prospective sites
    as described in 23 CFR 771.133 including agencies implementing the
    Endangered Species Act, the Migratory Bird Treaty Act, the National
    Historic Preservation Act, and 47 CFR 80 requirements relative to
    the DOC's Manual of Regulations and Procedures for Federal Radio
    Frequency Management

-   Acquiring or leasing 35 new properties for NDGPS reference stations

-   Acquiring new NDGPS reference station equipment

-   Transferring and installing GWEN equipment and new equipment at 35
    acquired sites

-   Testing and calibrating NDGPS and other equipment at each reference
    station

-   Operating and maintaining 67 NDGPS reference stations

-   Installing new equipment to expand the capacity of existing USCG
    control stations at Alexandria, Virginia, and Petaluma, California

-   Decommissioning the NDGPS reference stations, including
    environmental evaluations and audits, removal of equipment,
    restoration of property, as necessary, and the cessation of leases
    and agreements or transfer of land to the General Services
    Administration.

Phase I will allow users in most of the U.S. to obtain a DGPS correction
signal from at least one reference station by 2000. Phase II will allow
users in most of the U.S. to obtain a DGPS correction signal from at
least two reference stations (dual coverage) by 2002.

## Existing USCG DGPS Service

The USCG operates a series of ground-based reference stations which
provide local area DGPS service to GPS users along the Atlantic and
Pacific coasts, near the Mississippi River, in the Great Lakes region,
and in portions of Alaska and Hawaii. Fifty-four existing local area
DGPS reference stations exist in the CONUS and Alaska as shown in
Figures 4 and 5. The local area DGPS currently provides dual coverage
for the State of Hawaii. The areas covered by the existing DGPS service
in the lower 48 states and Alaska are shown on Figures 6 and 7,
respectively.

The proposed NDGPS would provide DGPS service to the 55 percent of the
area of the U.S. not currently served by the USCG system. Under the
preferred action (Alternative A) described in Section 4.2.1, this will
require the installation of 67 additional reference stations, mostly in
the interior regions of the continental U.S. and Alaska. As proof of
concept, one reference station has been installed at a former GWEN
station at Appleton, Washington.

## Proposed Reuse of GWEN Facilities and Equipment and installation of new NDGPS reference stations

Until recently, the USAF operated a series of unmanned GWEN relay node
stations around the country. The GWEN system was decommissioned by the
USAF Air Combat Command in 1998. Because of their similarities to the
NDGPS system, the existing GWEN relay nodes are well suited for reuse as
NDGPS reference stations. The government will be able to reuse all 53
GWEN relay nodes and 6 spare GWEN equipment sets for its NDGPS reference
stations.

Phase I will include the installation of NDGPS reference stations at 22
GWEN stations (including the existing NDGPS reference station at
Appleton, Washington), using surplus GWEN equipment at 10 new locations,
and using new equipment at 5 new locations (see Figures 8 and 9).
Estimated Phase I coverage from sites in the CONUS and Alaska are shown
in Figures 10 and 11, respectively. Under Phase II (dual coverage) an
additional 10 reference stations will be installed at former GWEN sites,
18 new reference stations will be installed using surplus GWEN
equipment, and 2 additional reference stations will be installed using
new equipment (see Figures 12 and 13). A list of GWEN relay nodes and
other (non-GWEN) sites proposed for NDGPS use is provided in Appendix C.
Estimated dual coverage from this proposed system is shown in Figures 14
and 15.

A typical GWEN relay node station contains a 299 ft-tall tower, radio
equipment shelter, antenna tuning unit (ATU) shelter, copper ground
plane, and security fences (see Figures 16 and 17). Six GWEN towers are
310 ft tall. A copper ground plane, buried one foot below the ground
surface, consists of 50 to 150 copper wires (0.128 inches in diameter)
extending in a radial pattern from the base of the 299 ft-tall tower.
Photographs of a typical GWEN relay node and associated equipment are
shown in Figures 18 through 20. The GWEN relay nodes formerly broadcast
a low-frequency radio signal for military use. The 299 ft antenna tower,
electrical equipment shelters, security fencing, ground plane, access
road, standby power generator, and utility connections at existing GWEN
facilities are all suitable for reuse at an NDGPS reference station. The
installation of two 30 ft-tall antennas, and electronic equipment will
be required to convert a GWEN relay node to an NDGPS reference station.

Figure 4 Locations of Existing USCG Local Area DGPS Reference Stations
(CONUS)

Figure 5 Locations of Existing USCG Local Area DGPS Reference Stations
(Alaska)

Figure 6 Existing USCG Local Area DGPS Coverage (CONUS)

Figure 7 Existing USCG Local Area DGPS Coverage (Alaska)

Figure 8 Existing USCG DGPS and Proposed NDGPS Reference Station
Locations---Phase I CONUS (Preferred Action Alternative)

Figure 9 Existing USCG DGPS and Proposed NDGPS Reference Station
Locations---Phase I Alaska (Preferred Action Alternative)

Figure 10 Estimated Phase I NDGPS Coverage (CONUS)

Figure 11 Estimated Phase I NDGPS Coverage (Alaska)

Figure 12 Existing USCG DGPS and Proposed NDGPS Reference Station
Locations---Phase I and II CONUS

Figure 13 Existing USCG DGPS and Proposed NDGPS Reference Station
Locations---Phase I and II Alaska

Figure 14 Estimated Phase II NDGPS Coverage and Remaining (Shaded) Phase
I Coverage (CONUS)

Figure 15 Estimated Phase II NDGPS Coverage (Alaska) Including Both
Single and Dual Coverage Areas

Figure 16 Typical GWEN Relay Node

Figure 17 Plan View of Typical GWEN Relay Node

Figure 18 Photograph: Representative GWEN Relay Node (Savannah Beach,
Georgia)

Figure 19 Photograph: GWEN Antenna Tuning Unit Shelter and Security
Fence (Savannah Beach, Georgia)

Figure 20 Photograph: GWEN Equipment Area (with 30 ft Tall UHF Antenna,
Radio Equipment and Backup Power Group Shelters)

## Description of Typical NDGPS Reference Station

An NDGPS reference station is an unmanned facility that continuously
broadcasts a radio signal at an operating frequency within the range 285
to 325 kilohertz (kHz). The signal has an effective range of up to 250
statute miles (mi) or approximately 400 kilometers (km).

Each reference station will require no more than 11.2 acres of land. A
conceptual NDGPS reference station layout is shown in Figure 21. The
most prominent feature will be a guyed steel-lattice tower located near
the center of the property, which supports an LF broadcast antenna. The
tower will be 299 ft in height and equipped with red warning lights
and/or a strobe beacon to reduce hazards to aircraft. At the base of the
tower will be an ATU shelter. A metallic ground plane or matting one
foot below the ground surface will be required for transmission of the
\~300 kHz signal. Similar to a GWEN relay node, this ground plane will
consist of 50 to 150 buried copper wires (aka radials), each up to 330
ft in length, extending outwards in all directions from a buried ground
mat centered near the base of the tower.

The FHWA will use property and/or GWEN equipment available from 53 GWEN
sites and 6 spare GWEN equipment sets. The 299 ft GWEN LF antenna,
backup power group (BUPG), and ATU and radio equipment shelters will be
retained. Since there is not enough GWEN equipment, new concrete
equipment shelters, BUPG shelters (or batteries), and LF antennas will
also be used. A typical equipment shelter is shown in Figure 22. An 8
ft-tall chain-link fence topped with barbed wire will surround the tower
and adjacent equipment shelter. In some locations, a shorter fence will
surround the copper ground plane. An area near the entrance to the
facility will also be fenced and will contain the radio equipment
shelter and a BUPG shelter. Shelters at all NDGPS reference stations
will use new, nonfreon air-conditioning units. These units contain R-22
(Refrigerant #22), a Class II refrigerant that has a recognized Ozone
Depleting Potential. This product is scheduled for production phase-out
but is appropriate for use until alternatives are available.

At each NDGPS facility a reference station antenna and an integrity
monitor receive antenna will be mounted on each of two approximately 30
ft-tall masts located outside the ground plane and near the equipment
shelter. The 25 kilowatt (kW) BUPG will provide electricity in case of
primary power failure.

The NDGPS reference station will require 3-phase electric power and
telephone service. Primary commercial electric power with 120/208 V
alternating current and a service connection of 100 A will be needed.
One telephone voice line and one telecommunications data line will be
needed to meet telecommunications needs. No staff will be stationed at
the reference station, which will be automated. Water service is not
needed, and no wastewater will be generated. An all-weather driveway
will be required for construction and long-term access for maintenance
and repair.

Figure 21 Conceptual NDGPS Reference Station Layout

Figure 22 Proposed NDGPS Equipment Shelter for Reference Stations Not
Using GWEN Equipment

## NDGPS Reference Station Maintenance

NDGPS reference stations will be maintained by the USCG. The USCG uses a
three-tier maintenance support structure. First response and routine
maintenance is the primary function of the local group office or
"organizational unit." Primary support for the local group office is
supplied at the district level or "support unit." These units provide
maintenance only and carry out quarterly visits using inspection and
maintenance procedures found in the USCG Index of Maintenance Procedures
and various GPS operator drawings, manuals, and guides. Key functions of
the maintenance team, typically consisting of two technicians, are
cleaning and inspection of electronic and physical components, testing
of electronic subsystems and components, and tests on various power and
environment support systems, such as batteries, fire suppression units,
and airflow equipment. Areawide support is provided by the regional
Electronics Maintenance Detachment (EMD) to resolve significant
technical problems.

## USCG Control Station

NDGPS will require the installation of more sophisticated electronic
monitoring equipment at USCG DGPS control stations in Alexandria,
Virginia, and Petaluma, California. The Alexandria and Petaluma stations
currently have eight and four staff members, respectively. These control
stations continuously monitor critical parameters at each USCG local
area DGPS reference station. With the addition of more efficient
equipment, the stations will be able to monitor and control the full
network of planned NDGPS reference stations, including the USCG local
area DGPS reference stations. Nine additional DGPS operators will be
stationed at those control stations.

# alternatives

## reasonable alternative TECHNOLOGies

### Screening GPS Technologies 

Augmentation of existing GPS is the most effective means of meeting
government and civilian user requirements for nationwide positioning and
navigation. A unique mix of technologies will be used for the NDGPS
system architecture chosen to meet user requirements. Nineteen GPS
technologies were considered for the development of an NDGPS
architecture (see Table 2). These include GPS augmentation technologies
that are in operation, likely to be put into operation, or are
conceptual, and that individually or in combination with other
technologies are likely to meet user requirements. Of the 19
technologies considered, 8 technologies were rejected because of lack of
technical feasibility, inability to meet user requirements, and/or an
insufficient development. Four other technologies were excluded because
they lack key elements required to meet one or more of the user
requirements (e.g., coverage over coastal or ocean areas or high failure
notification time). Seven were determined to be suitable for augmenting
existing GPS service (DOC NTIA, 1994).

A review of these suitable technologies concluded that no single one
would meet all federal DGPS user requirements. Except for the extremely
high accuracy and availability requirements of a highway collision
avoidance application, all other user requirements can be met through a
combination of technologies. During evaluation of the seven remaining
technologies, a key consideration was that an NDGPS will need to be
integrated into the existing USCG local area DGPS and the National
Geodetic Survey's CORS system to attain the accuracy needed for
ground-based GPS users.

### Selection of a System Architecture

In devising a multiple-technology architecture that best meets the
requirements for all anticipated uses, at least two GPS augmentation
technologies will be required: one primarily for users operating on the
earth's surface, and one primarily for aviation users. Using
combinations of the seven accepted technologies, six system
architectures were identified which maximized commonality and the
sharing of resources while reducing duplication of effort. Table 3
describes these six architectures.

Architecture 1 includes the use of the existing USCG local area DGPS in
conjunction with the planned Federal Aviation Administration (FAA)
technologies; however, this system does not provide nationwide coverage.
This architecture was rejected because it would not meet user
requirements or security needs.

<table>
<colgroup>
<col style="width: 6%" />
<col style="width: 6%" />
<col style="width: 17%" />
<col style="width: 13%" />
<col style="width: 0%" />
<col style="width: 14%" />
<col style="width: 10%" />
<col style="width: 2%" />
<col style="width: 8%" />
<col style="width: 4%" />
<col style="width: 14%" />
</colgroup>
<tbody>
<tr class="odd">
<td colspan="11">Table 2<br />
Proposed or Developed Augmented GPS Systems</td>
</tr>
<tr class="even">
<td><strong><br />
No.</strong></td>
<td colspan="4"><strong><br />
Augmented GPS Technology</strong></td>
<td colspan="2"><strong><br />
Responsible Entity</strong></td>
<td colspan="3"><strong>Proposed System</strong></td>
<td><strong>Operating System</strong></td>
</tr>
<tr class="odd">
<td>1*</td>
<td colspan="4">Low Frequency (LF)/Medium Frequency (MF) Radiobeacon
System (over waterways)</td>
<td colspan="2">USCG</td>
<td colspan="3"></td>
<td>X</td>
</tr>
<tr class="even">
<td>2*</td>
<td colspan="4">LF/MF Radiobeacon System (nationwide)</td>
<td colspan="2">DOT</td>
<td colspan="3">X</td>
<td></td>
</tr>
<tr class="odd">
<td>3</td>
<td colspan="4">Commercial Frequency Modulation (FM) Subcarrier
System</td>
<td colspan="2">Private</td>
<td colspan="3">X</td>
<td></td>
</tr>
<tr class="even">
<td>4*</td>
<td colspan="4">Wide Area Augmentation System (WAAS) 1 and FAA local
area DGPS</td>
<td colspan="2">FAA</td>
<td colspan="3">X</td>
<td></td>
</tr>
<tr class="odd">
<td>5*</td>
<td colspan="4">WAAS 2</td>
<td colspan="2">FAA</td>
<td colspan="3">X</td>
<td></td>
</tr>
<tr class="even">
<td>6*</td>
<td colspan="4">WAAS 3</td>
<td colspan="2">FAA</td>
<td colspan="3">X</td>
<td></td>
</tr>
<tr class="odd">
<td>7*</td>
<td colspan="4">WAAS 4</td>
<td colspan="2">FAA</td>
<td colspan="3">X</td>
<td></td>
</tr>
<tr class="even">
<td>8</td>
<td colspan="4">WAAS 5</td>
<td colspan="2">FAA</td>
<td colspan="3">X</td>
<td></td>
</tr>
<tr class="odd">
<td>9</td>
<td colspan="4">WAAS 6</td>
<td colspan="2">FAA</td>
<td colspan="3">X</td>
<td></td>
</tr>
<tr class="even">
<td>10*</td>
<td colspan="4">CORS System</td>
<td colspan="2">DOC</td>
<td colspan="3"></td>
<td>X</td>
</tr>
<tr class="odd">
<td>11</td>
<td colspan="4">Loran-C System</td>
<td colspan="2">USCG</td>
<td colspan="3"></td>
<td>X</td>
</tr>
<tr class="even">
<td>12</td>
<td colspan="4">Advanced Communications Technology Satellite (ACTS)</td>
<td colspan="2">NASA</td>
<td colspan="3">X</td>
<td></td>
</tr>
<tr class="odd">
<td>13</td>
<td colspan="4">Global Orbiting Navigation Satellite System
(GLONASS)</td>
<td colspan="2">Russia</td>
<td colspan="3"><mark></mark></td>
<td>X</td>
</tr>
<tr class="even">
<td>14</td>
<td colspan="4">Expanded GPS Constellation</td>
<td colspan="2">DOD</td>
<td colspan="3">X</td>
<td></td>
</tr>
<tr class="odd">
<td>15</td>
<td colspan="4">Inertial Navigation System (INS)</td>
<td colspan="2">Various</td>
<td colspan="3"></td>
<td>X</td>
</tr>
<tr class="even">
<td>16</td>
<td colspan="4">Sign Post System</td>
<td colspan="2">Unknown</td>
<td colspan="3">X</td>
<td></td>
</tr>
<tr class="odd">
<td>17</td>
<td colspan="4">Pseudolite System</td>
<td colspan="2">Unknown</td>
<td colspan="3">X</td>
<td></td>
</tr>
<tr class="even">
<td>18</td>
<td colspan="4">Dead Reckoning and Map Matching System</td>
<td colspan="2">Unknown</td>
<td colspan="3">X</td>
<td></td>
</tr>
<tr class="odd">
<td>19</td>
<td colspan="4">Omega System (existing network of very low frequency
[VLF] transmitters used for military and civil navigation, positioning,
and timing)</td>
<td colspan="2">DOD</td>
<td colspan="3"></td>
<td>X</td>
</tr>
<tr class="even">
<td colspan="11">*7 GPS systems considered for system architecture based
on technical feasibility, potential for meeting user requirements, and
level of development.</td>
</tr>
<tr class="odd">
<td colspan="11">Table 3<br />
System Architectures Versus User Requirements</td>
</tr>
<tr class="even">
<td colspan="2"><strong><br />
<br />
<br />
Architecture</strong></td>
<td><strong><br />
<br />
<br />
Technologies</strong></td>
<td><strong><br />
<br />
Nationwide<br />
Coverage</strong></td>
<td colspan="2"><strong>Aviation<br />
Requirements<br />
(ER, CAT I, II,<br />
III) Satisfied</strong></td>
<td colspan="2"><strong><br />
CORS<br />
Standard<br />
Compliant</strong></td>
<td><strong><br />
<br />
<br />
IOC</strong></td>
<td colspan="2"><strong><br />
<br />
<br />
Comments</strong></td>
</tr>
<tr class="odd">
<td colspan="2">1</td>
<td><p>USCG local area DGPS</p>
<p>FAA WAAS</p>
<p>FAA local area DGPS</p></td>
<td>No</td>
<td colspan="2">Yes</td>
<td colspan="2">Yes</td>
<td>1997</td>
<td colspan="2">No nationwide service</td>
</tr>
<tr class="even">
<td colspan="2">2</td>
<td><p>Expanded USCG local area DGPS</p>
<p>FAA WAAS</p>
<p>FAA local area DGPS</p></td>
<td>Yes</td>
<td colspan="2">Yes</td>
<td colspan="2">Yes</td>
<td>1997</td>
<td colspan="2">High performance; intermediate IOC</td>
</tr>
<tr class="odd">
<td colspan="2">3</td>
<td><p>Expanded USCG local area DGPS</p>
<p>Variant of FAA WAAS</p>
<p>FAA local area DGPS</p></td>
<td>Yes</td>
<td colspan="2">Yes</td>
<td colspan="2">Yes</td>
<td>&gt;1998</td>
<td colspan="2">High performance; later IOC</td>
</tr>
<tr class="even">
<td colspan="2">4</td>
<td><p>Expanded USCG local area DGPS</p>
<p>Modified FAA WAAS</p>
<p>FAA local area DGPS</p></td>
<td>Yes</td>
<td colspan="2">Yes</td>
<td colspan="2">Yes</td>
<td>&gt;1998</td>
<td colspan="2">Moderate performance; later IOC</td>
</tr>
<tr class="odd">
<td colspan="2">5</td>
<td><p>Expanded USCG local area DGPS</p>
<p>Modified FAA WAAS</p>
<p>FAA local area DGPS</p></td>
<td>Yes</td>
<td colspan="2">Yes</td>
<td colspan="2">Yes</td>
<td>&gt;1998</td>
<td colspan="2">Moderate performance; high security; high infrastructure
cost</td>
</tr>
<tr class="even">
<td colspan="2">6</td>
<td><p>Expanded USCG local area DGPS</p>
<p>Variant of FAA WAAS</p>
<p>FAA local area DGPS</p></td>
<td>Yes</td>
<td colspan="2">Yes</td>
<td colspan="2">Yes</td>
<td>&gt;1998</td>
<td colspan="2">Signal interference may occur (eliminated from
consideration)</td>
</tr>
<tr class="odd">
<td colspan="11">ER=en route; CORS=Continuously Operating Reference
Station; CAT=Category of Aircraft; IOC=Initial Operational
Capability</td>
</tr>
</tbody>
</table>

Architectures 2 and 3 were deemed the top two candidate architectures
for the NDGPS based on system performance, cost, and security factors.
Architecture 2, a nationwide system of USCG-like DGPS reference
stations, ranked highest overall, unless system security is an
overriding factor, in which case Architecture 3 would be selected.
Architectures 4 and 5 ranked lower in performance than Architectures 2
and 3. Architecture 6 was rejected because of concerns about signal
interference to aviation users, which was deemed unacceptable.

Security was not determined to be an overriding factor by the DOT.
Therefore, Architecture 2 was identified as the most advantageous
architecture for NDGPS (DOC NTIA, 1994).

Architecture 2 was therefore selected to meet land-based user
requirements. The DOT is proposing to deploy NDGPS reference stations at
strategic locations in two phases. Under Phase I, a GPS user anywhere in
the CONUS and Alaska will receive a differential correction signal from
at least one NDGPS reference station. Dual or redundant coverage, in
which a user would receive a signal from at least two reference
stations, will be available to GPS users in Phase II.

Because of the availability of former GWEN sites and equipment for the
expansion of local area DGPS, three possible deployment alternatives,
and the no-action alternative, are under consideration. Alternative A,
the preferred alternative, entails the use of GWEN sites and equipment
plus obtaining new sites and then relocating the remaining surplus
equipment from other GWEN facilities to some of these new sites.
Alternative B entails the use of GWEN sites and new sites using new
equipment similar to the GWEN equipment. Alternative C is the selection
of all new sites using new equipment similar to that now used for local
area service. For each alternative, a 1,000 W LF transmit antenna is
proposed. New NDGPS facilities under Alternatives A and B will operate
at 50 percent efficiency, or a maximum of 500 W effective radiated power
(ERP). USCG-like equipment used under Alternative C will operate at 17
percent efficiency or 170 W ERP. Alternative D is the no-action
alternative and would entail no future installation of NDGPS reference
stations.

## Description of alternatives ANALYZED IN DETAIL

### Alternative A (Preferred Action)---Mix of GWEN sites and equipment plus new sites and equipment

Alternative A, the preferred action for NDGPS service, would use a
combination of GWEN relay node sites and newly acquired (non-GWEN) sites
as locations for NDGPS facilities. By Phase II of the NDGPS program, 32
existing GWEN sites will have been identified for reuse, and 35 new
(non-GWEN) sites would be acquired to complete the system. Ownership of
all GWEN properties selected for NDGPS development will be transferred
from the USAF to either the USCG or the USACE for administration as
NDGPS properties.

Existing GWEN sites are typically 700 ft × 700 ft, or slightly over 11
acres. A short access and utilities corridor connects the GWEN site with
an existing public access road. Newly acquired properties for NDGPS
reference stations would also be about 11 acres in size and require
access and utilities corridors. Approximately 75 percent of the area at
a typical site would be used for the NDGPS facilities. The remaining
area would be used for staging and construction, and utilities and road
access to the sites. Conversion of existing GWEN relay nodes to NDGPS
use would not require new ground disturbance outside of the current site
boundaries.

Thirty-two selected GWEN relay nodes would be converted for reuse as
NDGPS facilities. Equipment from GWEN relay nodes and surplus GWEN
equipment would be installed at 28 newly acquired (non-GWEN) sites.
Newly manufactured DGPS equipment shelters and antennas would be
installed at seven additional (non-GWEN) sites, which would have the
same general size and layout configuration as a GWEN relay node.

A typical GWEN relay node with the 299 ft tower and ATU shelter is
described in Section 6 and presented in Figure 16. Conversion of the
existing GWEN facilities into NDGPS reference stations involves the
following actions:

-   Installation of two approximately 30 ft-tall masts (towers) and
    antenna equipment

-   Installation of two 4 ft × 4 ft × 6 ft concrete mast foundations
    located at the outer edge of the existing ground plane

-   Installation of a pull box at each mast location

-   Installation of a 1 sq ft DGPS junction box near the existing
    equipment enclosure

-   Installation of a 4-inch underground conduit between pull boxes and
    to the DGPS junction box

-   Hardwire connection of the DGPS mast ground to the existing ground
    plane

-   Removal or modification of other existing USAF equipment for
    compatibility with DGPS operation.

The 28 new NDGPS reference stations that would use GWEN equipment will
have a standard GWEN layout, including the 299 ft guyed tower, ground
plane, and BUPG and antenna equipment shelters. DGPS equipment as
described above will be installed. The transmitter equipment shelter and
BUPG (with a 500-gallon diesel fuel tank) will be installed near the
perimeter of the site, and security fencing will be placed in a manner
similar to the GWEN facilities. The 12 ft-wide access driveway will
connect to an existing public road and lead to the base of the transmit
antenna tower. Aboveground 3-phase commercial power and telephone lines
will be brought onto the site along the 12 ft-wide access road.

At the remaining seven new sites, NDGPS equipment having the same
configuration as GWEN equipment will be installed, including the 299 ft
tower. Site layout and equipment installation would be as described
above for the NDGPS reference stations using GWEN equipment. For easier
reference, Table 4 breaks out the types and number of properties
required for each alternative.

  --------------------------------- ---------------- ---------------- ---------------- ----------------
  Table 4\                                                                             
  Number of Properties to be                                                           
  Acquired Under Each Alternative                                                      
  at Full Buildout                                                                     

  **\                               **Alternative\   **Alternative\   **Alternative\   **Alternative\
  Type of Components**              A**              B**              C**              D**

  GWEN relay node sites with reuse  32               --               --               0
  of GWEN equipment (299 ft tower)                                                     

  GWEN relay node sites with new    --               32               --               0
  equipment (299 ft tower)                                                             

  Non-GWEN sites with GWEN          28               --               --               0
  equipment (299 ft tower)                                                             

  Non-GWEN sites with new equipment 7                35               --               0
  (299 ft tower)                                                                       

  Non-GWEN sites with USCG          --               --               80--100          0
  equipment (120 ft tower)                                                             
  --------------------------------- ---------------- ---------------- ---------------- ----------------

Construction equipment used to install NDGPS includes a backhoe for
trenching and ground plane installation, a front-loading tractor, and a
large forklift to unload shelters. The tower can be erected in several
ways: with a single crane; with a winch truck and gin pole; with a crane
for the first 100 ft followed by use of a winch truck; or with a
heavy-lift helicopter (Pugh, 1998). Other vehicles to be used at the
construction site include up to four equipment delivery trucks and
private commute vehicles for construction workers.

Installation of the proposed facilities at existing GWEN sites would
require a maximum of 10 workers over a 30- to 45-day construction
period. For construction at new, non-GWEN sites, a maximum of 15 workers
over a 2- to 3-month construction period would be needed (Pugh, 1998).

No unusual infrastructure or utility requirements will be needed for
installation of this alternative. The cost of equipment acquisition and
installation for 67 sites under this alternative is expected to be
\$30.3 million. Annual operating costs are estimated to be \$2.5
million, and annual maintenance costs are expected to be \$2.1 million
(NDGPS PIT, 1998). The FRA would pay for costs of installing, operating,
and maintaining NDGPS, although operation and maintenance would actually
be carried out by USCG personnel (see Appendix A).

### Alternative B---Mix of GWEN sites and new sites using new equipment

Alternative B involves the use of existing GWEN sites and new (non-GWEN)
sites as locations for NDGPS facilities. As described above for the
preferred action, 32 GWEN relay node sites will be required for use and
35 newly acquired non-GWEN sites would need to be identified and
acquired to achieve dual coverage under Phase II of the NDGPS program
(see Table 4, above).

Except for the ground plane, no GWEN equipment would be reused or
relocated for NDGPS facilities at any of the existing GWEN sites or
newly acquired non-GWEN sites. Instead, new DGPS equipment would be
acquired and installed at all 67 sites. The ground plane at 32 existing
GWEN sites would be reused. Equipment installation, utilities, and
access road installation would be as described above for newly acquired
sites in Alternative A, except new DGPS equipment would be installed. A
299 ft-tall tower would be used at all sites (see Table 4, above).
Project information in terms of land acquisition and property ownership,
site size, and required construction equipment is identical to
Alternative A.

Installation of the proposed facilities at existing GWEN sites would
employ a maximum of 10 persons over a 30- to 45-day construction period.
For construction at new sites, a maximum of 15 persons over a 2- to
3-month construction period would be needed. Although new equipment will
be installed at all sites, the number of days needed for installation at
existing GWEN sites is reduced because of the reuse of the existing
ground plane.

No unusual infrastructure or utility extensions will be needed for
installation of Alternative B. The cost of equipment acquisition and
installation for 67 sites under this alternative is expected to be about
\$37.2 million. Likewise, annual operating and maintenance costs are
\$2.5 million and \$2.1 million per year, respectively. The FRA would
pay for costs of installing, operating, and maintaining NDGPS. USCG
personnel would install, operate, and maintain the NDGPS equipment (see
Appendix A).

### Alternative C---All new sites using standard USCG equipment

Alternative C for the deployment of an NDGPS service involves the
identification and development of new site locations for facilities very
similar in size and capability to the existing USCG local area DGPS
stations now in use. Approximately 80 to 100 new sites ranging in size
between 2 and 11 acres would be required to expand the existing local
area DGPS service to a nationwide dual coverage system using the current
standard USCG equipment (see Table 4, above). Standard USGS local area
DGPS reference stations use a single transmit antenna ranging between 90
and 120 ft in height, including a copper ground radial plane.

Site acquisition would be undertaken by the USACE, and as with
Alternatives A and B, the USCG and USACE would administer the
properties. Construction equipment needs would also be the same as
described for Alternatives A and B. Installation of the proposed
facilities at all site locations would require a maximum of 15 persons
over a 2- to 3-month construction period (Pugh, 1998).

The cost of equipment acquisition and installation is expected to be
\$44 million. Annual operating costs are estimated at \$3.6 million and
annual maintenance costs are estimated at \$3.1 million (NDGPS PIT,
1998). As with Alternatives A and B, the FRA would pay for the cost of
installation, operation, and maintenance, and USCG personnel would carry
out operation and maintenance responsibilities (see Appendix A).

### Alternative D---No-action alternative

Under the no-action alternative, the existing GWEN system of facilities
would continue to be decommissioned by the USAF. In this case, the USAF
will continue to cease operations and intends to remove equipment at all
GWEN properties (USAF, 1995). An environmental assessment for each of
these actions will be prepared by the USAF. Those GWEN facilities
located on leased property would be returned to private use. Properties
purchased by the USAF for GWEN relay nodes would revert to the General
Services Administration for possible reuse by another federal agency or
resale out of federal ownership (USAF, 1987). The USCG would continue to
operate its local area DGPS reference stations. No undeveloped or
previously developed properties would be altered for use as NDGPS
reference stations. The current accuracy, reliability, and availability
of existing SPS service would remain unchanged.

# affected environment

The proposed NDGPS reference stations will be located in the interior
portions of the CONUS and Alaska. Nearly level property away from tall
objects and structures is preferred for installation of reference
stations. There is a relatively large area within which candidate sites
for a reference station may be located. Given this flexibility, the
government intends to select locations for reference stations so as to
minimize the potential effect on the environment. This section discusses
the range of conditions that may be present at candidate sites, sources
of site-specific resource information, and the regulatory setting within
which the resource is managed or protected.

The proposed NDGPS network of reference stations will use existing GWEN
sites and equipment, and/or deploy similar equipment at new sites. Given
the similarity of these two programs, portions of the GWEN Final EIS
have been used in this section when appropriate.

## Geology AND SOILs

### Resources Affected

Geological resources consist of soil and bedrock including
unconsolidated and consolidated earth materials. Resources include the
construction engineering properties of the materials, economic mineral
deposits, significant or unique landforms, and paleontological (fossil)
remains. The NDGPS program may affect or be affected by the geological
environment. Major potential geological constraints to the project
include seismic shaking and soil instability. The United States has been
subdivided into six seismic zones and classified according to the
potential for seismic hazard within that zone. Zones range from 0 to 4
(0, 1, 2A, 2B, 3, and 4) with the higher number indicating increasing
potential for damage (International Conference of Building Officials,
1997). Zones 0 through 2 are found throughout the United States, while
Zones 3 and 4 occur in the western and Rocky Mountain states and Alaska.

Soil instability is found on steep slopes of 5 percent or greater or in
areas with highly erodible soil. These conditions can be found in all
regions of the United States.

Mineral resources are widely distributed and include all types of rock
and rock-derived material which has some economic use including fossil
fuels, construction and building materials, metals, gemstones, and
nonmetallic raw materials. Sand and rock quarries are the most common
type of economic mineral deposit, and extraction sites may occur
throughout the U.S. Oil and gas reserves are located throughout the U.S.
Oil and gas production wells are typically spaced at one well per every
40 to 640 acres.

Paleontological resources are also present throughout the U.S. and may
occur where bedrock is exposed on the surface, typically where erosion
has exposed subsurface features or in mountainous terrain, and also in
alluvial and lacustrine deposits.

### Data Sources

Data on geological conditions and related resources, such as flooding,
soil characteristics, terrain and paleontological resources, are
available from the U.S. Geological Survey (USGS), the Natural Resource
Conservation Service (NRCS), the U.S. Forest Service (USFS) and the
USACE. Information on paleontological resources located on lands
administered by the BLM or Bureau of Reclamation (BOR) is available from
those federal agencies. Information on seismic zones is contained in the
International Conference of Building Officials *Uniform Building Code*
(1997). Sources of data at the state level include state offices of
geology, natural resources, environmental conservation, emergency
management, and oil and gas regulation, among others. Other independent
sources include research and review by land development and resource
extraction industries, and independent clubs and organizations.

### Regulatory Setting

The code governing construction and design of NDGPS facilities within an
assigned seismic hazard zone is contained in the 1997 *Uniform Building
Code*. Procedures and guidelines developed by the USFS, BLM, or BOR for
the protection, survey, and excavation of paleontological resources
located on lands under their jurisdiction reside with those agencies.
State regulations and management practices may also apply.

## water quality

### Resources Affected

Water resources include surface water and groundwater and their
physical, chemical, and biological conditions. The anticipated physical
and chemical factors that influence local water quality and surface
water runoff, including the effects of erosion and sedimentation, are
discussed below. Floodplain and wetland resources are discussed
separately in Section 5.3, Ecologically Sensitive Areas.

Water resources such as lakes, rivers, streams, canals, and drainage
ditches make up the surface hydrology of a given watershed. Groundwater
resources consist of subsurface hydrology in which one or more aquifers
may be present. Aquifers perched near the ground surface may
significantly influence local surface water levels, flow rates,
salinity, and chemistry.

The buried copper radials used for the NDGPS (or former GWEN) antenna
may be subject to corrosion, potentially resulting in increased copper
concentration near the antenna ground plane. This aspect of NDGPS
development on water quality depends on baseline copper concentrations,
depth to groundwater, soil acidity, and water hardness (CaCO~3~).
Increased hardness is associated with greater buffering capacity and
reduced toxicity of copper (USAF, 1987). Except in acidic soils, copper
mobility is generally limited because of insolubility, adsorption,
and/or complexation (USAF, 1987). For the protection of aquatic life,
the 1997 EPA standards for copper concentrating in water contained in 40
CFR 131 are dependent on water hardness. Table 5 indicates the allowable
maximum and continuous concentrations of dissolved copper in freshwater
depending on water hardness or CaCO~3~ content.

+-----------------------+-----------------------+-----------------------+
| Table 5\              |                       |                       |
| Freshwater Toxics     |                       |                       |
| Criteria for          |                       |                       |
| Dissolved Copper (40  |                       |                       |
| CFR 131.36) July 1,   |                       |                       |
| 1997                  |                       |                       |
+-----------------------+-----------------------+-----------------------+
| **\                   | **Criterion\          | **Criterion\          |
| Hardness^1^\          | Maximum               | Continuous            |
| CaCO~3~ (mg/l)**      | Concentration^2^\     | Concentration^3^\     |
|                       | (µg/l)**              | (µg/l)**              |
+-----------------------+-----------------------+-----------------------+
| 25                    | 5                     | 3                     |
+-----------------------+-----------------------+-----------------------+
| 50                    | 9                     | 6                     |
+-----------------------+-----------------------+-----------------------+
| 75                    | 13                    | 9                     |
+-----------------------+-----------------------+-----------------------+
| 100                   | 17                    | 11                    |
+-----------------------+-----------------------+-----------------------+
| 150                   | 25                    | 16                    |
+-----------------------+-----------------------+-----------------------+
| 200                   | 33                    | 21                    |
+-----------------------+-----------------------+-----------------------+
| 300                   | 48                    | 29                    |
+-----------------------+-----------------------+-----------------------+
| 400                   | 63                    | 37                    |
+-----------------------+-----------------------+-----------------------+
| \_\_\_\_\_            |                       |                       |
| \_\_\_\_\_\_\_\_\_\_\ |                       |                       |
| _\_\_\_\_\_\_\_\_\_\_ |                       |                       |
|                       |                       |                       |
| ^1^The hardness level |                       |                       |
| used for calculations |                       |                       |
| must be no less than  |                       |                       |
| 25 and no greater     |                       |                       |
| than 400, regardless  |                       |                       |
| of\                   |                       |                       |
| the actual hardness   |                       |                       |
| value at the site (40 |                       |                       |
| CFR 131.36 c(4)).     |                       |                       |
|                       |                       |                       |
| ^2^Criterion Maximum  |                       |                       |
| Concentration (CMC) = |                       |                       |
| the highest           |                       |                       |
| concentration of a    |                       |                       |
| pollutant to which    |                       |                       |
| aquatic life\         |                       |                       |
| can be exposed for a  |                       |                       |
| short period of time  |                       |                       |
| (1-hour average)      |                       |                       |
| without deleterious   |                       |                       |
| effects.              |                       |                       |
|                       |                       |                       |
| ^3^Criterion          |                       |                       |
| Continuous            |                       |                       |
| Concentration (CCC) = |                       |                       |
| the highest           |                       |                       |
| concentration of a    |                       |                       |
| pollutant to which    |                       |                       |
| aquatic life\         |                       |                       |
| can be exposed for an |                       |                       |
| extended period of    |                       |                       |
| time (4 days) without |                       |                       |
| deleterious effects.  |                       |                       |
+-----------------------+-----------------------+-----------------------+

### Data Sources

Data on the location and condition of regional watershed resources is
available from both the EPA and USGS water programs and resource maps.
The USGS publishes the National Water Summary for water resources
nationwide, and their National Water Quality Assessment Program provides
water quality information for specific "study units." The EPA STORET
environmental data system, which provides additional water quality and
other descriptive information, is available via the Internet. Finally,
the *Groundwater Atlas of the United States* (USGS, 1998) is another
source of water resource information.

The potential for erosion and sedimentation can be identified by soil
type from soil surveys prepared by the NRCS for each county or portion
of a county. Soil classifications are ranked by several criteria,
including their potential for severe erosion. The universal soil loss
equation prepared from NRCS data is a standard method for quantifying
anticipated losses of soil by erosion. This quantitative assessment of
whether significant erosion would occur is typically applied on a
site-by-site basis if a potential for severe erosion exists. For some
locations, quantification of water runoff may be required for state or
county project review requirements. Water runoff is typically a concern
in low-lying areas near sea level, such as the coastal Gulf states and
in mountain valleys. It is a concern when large impervious areas replace
exposed soils that formerly promoted infiltration of standing water.

Typically, sources of data at the state level include state and county
departments of water quality, environmental conservation, and
environmental protection. Other independent sources include municipal
water treatment data and independent sampling by private health,
scientific and environmental organizations.

### Regulatory Setting

The Clean Water Act of 1977 (as amended) is the primary law regulating
water pollution and gives the EPA the authority to set water quality
standards for contaminants in surface waters. The EPA publishes surface
water quality standards and toxic pollutant criteria at 40 CFR Part 131.
In 1997, the EPA updated its standards based on water hardness to
protect aquatic life from excessive copper concentrations (40 CFR
131.36).

## ecologically sensitive areas

### Resources Affected

Ecologically sensitive areas include jurisdictional wetlands and the
100-year floodplain. According to the USACE definition of wetlands
contained in 33 CFR 328, three necessary conditions must be met in order
for an area to be classified as jurisdictional wetlands: the area must
contain hydric soils; it must support hydrophilic vegetation; and it
must have an appropriate hydrologic regime. Typical wetland areas
include marshes, swamps, and bogs, and, in general, are transitional
zones between terrestrial and aquatic ecosystems. Wetlands are of prime
importance to waterfowl and provide critical habitat for numerous other
wildlife. Wetlands occur throughout the U.S. and are delineated based on
regional or local criteria determined by the USACE. Where the presence
or absence of jurisdictional wetlands is not known, delineation of
wetland boundaries using criteria accepted by the USACE may be required.

Floodplains are lowlands and "relatively flat areas adjoining inland and
coastal waters including floodprone areas of offshore islands, including
at a minimum, that area subject to a one percent or greater chance of
flooding in any given year" (President, 1977). A 100-year floodplain is
an area subject to flooding on average more than once every 100 years.
The 100‑year floodplain may be present in low-lying regions throughout
the U.S., particularly in the Midwest and Gulf states, and in mountain
valleys and coastal areas.

### Data Sources

The locations of known wetlands are available from the U.S. Fish and
Wildlife Service (USFWS) National Wetlands Inventory maps. NRCS soil
surveys and separate soil listings delineate areas that may contain
hydric soils or hydrophilic vegetation. Field studies may be required to
confirm the presence or absence of jurisdictional wetlands. Flood
Insurance Rate Maps indicating the boundary of the 100-year floodplain
are available from the Federal Emergency Management Agency (FEMA).

### Regulatory Setting

Section 404 of the Clean Water Act of 1977 (as amended) regulates
development in wetlands and surface water bodies, and requires agencies
to obtain a permit from the USACE to dredge or fill in U.S. waters.
Executive Order 11990---Protection of Wetlands, directs federal agencies
to avoid to the extent possible adverse impacts associated with the
destruction or modification of wetlands. Executive Order
11988---Floodplain Management and Protection, directs federal agencies
to avoid to the extent possible the long- and short-term adverse impacts
associated with the occupancy and modification of floodplains and to
avoid direct or indirect support of floodplain development wherever
there is a practicable alternative.

## air quality

Air quality for a given location is characterized by the concentration
of various key pollutants in the atmosphere. Parts per million (ppm) or
micrograms per cubic meter (µg/m^3^) are typical units for atmospheric
pollutants. A significant impact on air quality may occur for incidents
in which federal and state air quality standards are exceeded or where
hazardous air pollutants may adversely affect public health. Short-term
air emissions would occur during construction and decommissioning
activities, principally from site clearing activities, if any, and the
use of construction equipment and related vehicles. Long-term air
emissions would occur during operation of the NDGPS reference station
because of infrequent use of the BUPG during disruption of commercial
power.

### Resources Affected

The National Ambient Air Quality Standards (NAAQS) specify allowable
pollutant concentrations at which public health and welfare are
protected with a reasonable margin of safety. The criteria pollutants
under federal and state standards are ozone (O~3~), carbon monoxide
(CO), nitrogen dioxide (NO~2~), sulphur dioxide (SO~2~), total suspended
particulates (TSP), particulate matter under 10 microns (PM10), and lead
(Pb). Key factors affecting air quality conditions for a location or
region are pollutant emission rates, emission parameters, topographic
features, chemical reactions, cumulative effects from other emission
sources, and meteorological conditions. If criteria pollutant standards
are exceeded more than once per year, that area is designated as being
in nonattainment. For nonattainment areas, each state submits for
approval a State Implementation Plan that will bring the affected air
basin into attainment with the NAAQS. Air emission regulations are more
stringent in nonattainment areas and vary from air basin to air basin.

Areas with very clean air are required to adhere to Prevention of
Significant Deterioration (PSD) requirements concerning major new
emission sources. Areas in which PSD requirements apply include federal
wilderness areas and other settings possessing pristine air quality.

### Data Sources

The Council on Environmental Quality (CEQ) annually summarizes the
nation's air quality. Data from the annual reports are gathered by the
EPA from national, state, and local air-quality monitoring sites,
typically located in urban or industrial areas. Data for specifically
designated air basins within the U.S. are also available.

Data on air quality standards and air basin conditions are available
from state and regional air pollution control agencies and air quality
management district offices. Whether a proposed action is in compliance
with rules and regulations for a particular air basin is determined on a
site-by-site basis. Areas in attainment and not subject to PSD
requirements are not expected to require site-specific air quality
analysis.

### Regulatory Setting

The Clean Air Act Amendments of 1990 (as amended) set the NAAQS, while
State Implementation Plans for areas in nonattainment with NAAQS are
prepared by each state and the appropriate regional air quality
management district.

## noise

### Resources Affected

Noise is unwanted sound heard by people or wildlife in the vicinity of
the project area because of activities related to the construction,
operation, and maintenance of the proposed facilities. Noise can be
intermittent or continuous, steady or impulsive, and may involve any
number of sources and frequencies. It may be readily identifiable or
generally nondescript. Human response may vary depending on the source,
listener sensitivity and expectations, the time of day, and the distance
from the source. Noise is measured in decibels (dB), usually adjusted to
the A-scale. Affected receptors are specific or areawide locales in
which occasional or persistent sensitivity to noise above ambient levels
exists, such as at or near hospitals, amphitheaters, nursing homes, and
certain locally designated districts.

NDGPS reference stations will be located in a variety of local
environments. While no land-use type can be eliminated from selection,
dense urban environments having the highest ambient noise levels are
less likely to be selected. Wilderness areas, parks, and rural
communities possess low ambient noise. This last setting is typical for
many GWEN relay nodes. Suburban areas may have the greatest amount of
noise-sensitive receptor locations.

### Data Sources

Published data on anticipated noise levels of typical construction
equipment are available in Bolt et al. (1971). Published federal, state,
or local laws, ordinances, regulations, and standards can be obtained
for comparison with anticipated noise emissions.

### Regulatory Setting

The EPA administers the Noise Control Act of 1972, and has identified 55
dB (A-scale) as a desirable noise level for residential use. This level
is not regarded as a noise standard, but simply a basis for state and
local governments to set appropriate standards that should also factor
in local considerations and issues. The FHWA has established long-term
peak hourly noise level standards for the design of highway projects in
various types of land-use settings.

The 1982 FHWA Federal Highway Program Manual 7-7-3 was used to assess
the relative effects of noise. It establishes long-term average peak
hourly noise levels for various land-use categories. For the most highly
sensitive receptor areas, such as hospitals and parks, exterior noise
levels of 57 dB (A-scale) or less are recommended. For areas containing
moderately sensitive land uses, such as residences, hotels, and schools,
an exterior noise level of 67 dB (A‑scale) or less is recommended. For
other developed lands, an exterior noise level of 72 dB (A‑scale) or
less is recommended.

## Visual Resources

### Resources Affected

Visual resources comprise the natural and man-made features that give a
particular environment its aesthetic qualities. These features form the
overall impression that a viewer has of an area or its landscape
character. Landforms, water surfaces, vegetation, and man-made features
are considered characteristic of an area if they are inherent to the
composition and function of the landscape. The landscape character is
studied to determine whether a new element would appear compatible with
the affected setting or would noticeably contrast in such a way as to
diminish its character or aesthetic quality (USAF, 1987).

Methods to assess visual resources based on public values, goals,
awareness, and concern have been developed by the BLM (BLM, 1986). The
Visual Resource Management (VRM) system helps to define the visual
sensitivity of an area and the degree of potential effect on a visual
resource. Of particular concern are state and locally designated scenic
highways and recognized visual settings governed by local comprehensive
plans and ordinances, which are common within coastal, recreation, and
open space areas, and historic properties or districts. These are of
moderate sensitivity. Areas of national significance, such as national
parks, wild and scenic rivers, monuments, and landmarks are areas of
potentially high visual sensitivity.

Four broadly defined landscapes would occur within the potential
settings of the proposed project. These four landscapes consist of
natural, rural, urban, and transitional landscapes (USAF, 1987) and are
briefly described below.

Natural landscapes are those in which natural-appearing landforms and
vegetation predominate, and signs of human activity are not readily
apparent. Coastlines, water bodies, mountainous landforms and areas of
varied relief are the most striking and tend to be the most conspicuous.
More sparsely vegetated mountainous areas in the western U.S. are
dominated by their landform, such as rock outcroppings, ridges,
escarpments, and plateaus. Natural areas within the eastern third of the
continental U.S. are typically heavily forested. Even where there is
substantial relief, the heavily forested landforms are undistinguished
and tend to confine a viewer's attention to the immediate foreground.
Tower facilities would be least compatible within a natural landscape;
however, for areas in which a forested area offers a diverse skyline or
visual screening, the conspicuity of the structure would tend to be
lower.

Rural landscapes include features such as croplands, orchards, fields,
fences, and farm-related structures. Agricultural areas are
predominantly flat or gently rolling hills. Native vegetation is present
in confined areas where land is steep or soils are unproductive. Views
may extend for some distance, with typically vertical elements
consisting of relatively low farm buildings, silos, water towers,
utility poles and trees. Distinct geometric patterns are often observed,
such as rectangular or circular fields and property boundaries divided
by section lines. Towns are small and contain a relatively low skyline
profile. In general, structures are relatively few but can be of
aesthetic interest and the landscape is noticeably influenced by
agricultural practices. Other rural areas are forested or desert in
character and are influenced by roadways, towns, and land-clearing
actions such as timber harvesting, strip mining, ski areas, and large
reservoirs.

Urban landscapes represent only a fraction of the nation's entire land
area, but it is the dominant visual environment of roughly
three-quarters of the U.S. population. Residential and suburban areas
represent much of the urban landscape, with a centralized primary
commercial center and business district defining the most dominant
visual setting. Heavy and light industry tend to be scattered and
located within specific zones or districts, such as along permanent
roadways and waterfronts or near airports. The scale of development in
major urban areas is large, dominated by structures, freeways,
infrastructure and trees. Urban landscapes can absorb the greatest
degree of visual change because of the dominant visual features
contained within it. For tower structures, the presence of other similar
towers in the region, the complexity and relief of the skyline, and the
screening of view by structures and trees will lessen the potential for
significant visual impact.

Transitional landscapes are those that contain common features of two or
more of the dominant landscapes mentioned above. They represent a
gradual change from one landscape type to another. Visual landscapes
between urban and rural areas are generally the most capable of
absorbing visual change.

### Data Sources

Data on visual resources and landforms are available from USGS
topographic maps, road maps, regional transportation and planning maps,
and from field investigations by experienced observers. Observation and
analysis of visual effects are effectively categorized using the BLM VRM
system. This method is simplified for use during NDGPS site-selection
activities and can be applied to non-BLM lands.

Significance of impact should be based on visual dominance and visual
sensitivity. The extent to which a project element is visually dominant
relative to the affected landscape can be classified according to the
BLM VRM classifications in Table 6.

  ----------------- --------------- ----------------------------------------------------
  Table 6\                          
  BLM VRM                           
  Classifications                   

  **Class**         **Dominance**   **Description**

  I                 Not noticeable  The change would generally be overlooked

  II                Noticeable      Visually subordinate; change is subtle but noticed
                                    by most without being pointed out

  III               Distracting     Visually codominant; change competes strongly for
                                    attention and is equally conspicuous with other
                                    features

  IV                Dominant        Demands attention; change to landscape is the focus
                                    of attention and becomes the primary focus of the
                                    viewer
  ----------------- --------------- ----------------------------------------------------

Visual sensitivity reflects the level of viewer awareness and value
placed on a particular scene or setting. Highly sensitive areas are
typically designated as being of significant importance to the general
public. These include national and state parks, designated wild and
scenic rivers, historic sites, memorials, recreational areas, scenic
roadways, overlooks, trails and rivers, wilderness areas, and other
areas designated for special outdoor public use. Some travel routes,
including roads, trails, bicycle paths, and equestrian trails at or
leading to areas known for their unique scenic quality, are also
considered to be highly sensitive. Medium sensitivity areas are affected
areas or travel routes having no specific designation but lead to areas
of special interest. Undesignated, but protected or popularly used areas
of aesthetic, recreational, cultural, or scientific significance are
present and are often identified by local, state, or county
jurisdictions. Low sensitivity areas are those in which the general
public is expected to have no more than a minor concern about changes in
the landscape. Views in these areas are not unlike others in the general
vicinity, and sensitivity remains low when viewed from any viewpoint or
travel route not considered to be either medium or high in sensitivity.

### Regulatory Setting

Regulations and planning documents that address potential effects to
visual resources include federal management policies for public lands,
particularly lands managed by the BLM and the USFS. Specific regulations
containing federal requirements for visual resource assessment include
the National Forest Management Act of 1976 (as amended), the Federal
Land Policy and Management Act of 1976 (as amended), the Wild and Scenic
Rivers Act of 1968, and the resource management policies of the BLM and
USFS.

## flora and fauna

### Resources Affected

Flora and fauna resources include native and exotic plant species (or
vegetation) and indigenous or migratory animal species (or wildlife) and
their habitats. These resources include plant populations and
communities, and wildlife populations and their relationship to habitat,
including aquatic, wetland, and riparian ecosystems. Of principal
concern are direct or indirect effects upon state and federally
protected species or their prime habitats. Lists of protected flora and
fauna are prepared for each county and periodically updated by the
regional or local field office of the USFWS. Current lists of
state-listed species reside with the equivalent state-level agency
and/or the natural heritage database.

There are numerous settings in which state- and federally listed plant
and wildlife species may occur. Common, broadly classified ecosystems
include deserts, grasslands, scrub, woodlands and forests, aquatic,
wetlands, and riparian areas. In addition to threatened and endangered
species, flora and fauna protected by other federal and state laws must
be considered. This includes the potential for mortalities to indigenous
and migratory birds because of tower strikes. Typically, the location of
new, tall guyed towers between large migratory bird stopover and feeding
areas within the Central, Pacific, and Atlantic Flyways should be chosen
to avoid areas where low flyovers (below 300 ft) occur. Also, federal
regulations for some areas may require the use of utility pole
cross-arms designed to eliminate the potential for raptor
electrocutions.

Other types of critical habitat occur in areas with broad, natural
occurring ecosystems, such as old growth coniferous forests in the
Pacific Northwest, long-leaf pine forests of the lower eastern seaboard,
and undisturbed areas within the southwestern deserts. Numerous other
types of valuable habitat areas are present and must be considered
during site-specific investigations for suitable properties.

### Data Sources

To effectively consider effects upon flora and fauna, site-specific
information and regulatory agency input are required. USFWS Recovery
Plans for federally protected species and species location information
on state natural heritage database records are excellent sources. Any
conflict between observed or documented ecosystems identified on-site
and critical habitat required to sustain protected species should be
evaluated by a qualified botanist or wildlife biologist. Initial
screening for conflicts with critical habitat can be made using on-site
observations and published information.

### Regulatory Setting

The principal federal statute pertaining to the protection of plants and
animals is the Endangered Species Act of 1973 (as amended), which
requires protection of federally listed threatened and endangered
species and their habitats. Other federal statutes include the Migratory
Bird Treaty Act of 1918 (as amended), the Fish and Wildlife Coordination
Act of 1958 (as amended), and the Bald Eagle Protection Act of 1940. For
coastal and marine locations, the Marine Mammal Protection Act of 1972
(as amended) and the Coastal Zone Management Act of 1972 (as amended)
would apply. Various state laws protecting state-listed plant and animal
species or habitat areas of special concern must also be considered
during the siting and development of NDGPS facilities.

## cultural resources

### Resources Affected

Cultural resources that could be affected by construction and operation
of an NDGPS reference station include prehistoric-archaeological,
historic, architectural, and Native American (American Indian and Native
Alaskan) resources. Prehistoric-archaeological resources are defined as
physical remnants of human occupation that predate the advent of written
records in a particular culture and geographic region. These resources
typically include archaeological sites, dwellings and structures,
artifacts, midden heaps, and other evidence of prehistoric human
activity. Historic resources consist of physical properties or locations
postdating the advent of written records. In addition to the artifacts
mentioned above, historic resources may also consist of written records
and locations associated with events that have made a significant
contribution to history or that are associated with the lives of
historically significant persons. Architectural resources include
historic/prehistoric structures, buildings, and other objects related to
prior human occupation. American Indian and Native Alaskan cultural
resources may be prehistoric archaeological sites, artifacts, burial
grounds, areas of prior occupation and events, historic and contemporary
sacred areas (traditional cultural properties), hunting and gathering
areas, cultural landscapes, and other botanical, biological, and
geological resources of importance to contemporary Native American
groups. Traditional cultural properties can often be bounded areas
defined by symbolic associations with religious or cultural practices,
historic events, or other concepts and not necessarily manifested by
physical remains.

Areas of potential impact to cultural resources include properties,
structures, landscapes, or traditional cultural sites that qualify for
listing in the National Register of Historic Places (NRHP). While
typical locations of previously unknown cultural resources are
subsurface artifacts and sites located on undeveloped properties,
developed sites with structures greater than 50 years old may be
eligible for the NRHP. Historic districts, landscapes, or clusters of
similar historic properties related to a common theme or locale may
occur in prospective NDGPS site areas. Undocumented or unidentified
traditional cultural sites or landscapes may also exist at or near
prospective NDGPS sites. Visual, noise, atmospheric, and physical
impacts must be considered during NDGPS site evaluations near these
resources.

### Data Sources

Data sources include those available from the State Historic
Preservation Office (SHPO) and from NRHP-eligible properties and
landmarks listed in the National Register Information System (NPS,
1998). Information from the SHPO or other databases on the presence of
prior cultural resource studies in the vicinity of the project's site
search area are also valuable. For some areas, regional prehistoric,
historic, and ethnohistoric descriptions and accounts that summarize
cultural properties and lifestyles found in the U.S. may be appropriate.
Definitive information regarding the presence or absence of cultural
resources is obtained from on-site cultural resource investigations by a
qualified archaeologist or architectural historian. Ethnographic
information, including information on traditional cultural properties,
may be available from regional historians or must be obtained by
ethnographic research and interviews with traditional cultural leaders
from tribal groups or other Native Americans.

### Regulatory Setting

Numerous federal laws govern the treatment of cultural resources on
lands administered or managed by federal agencies or that may
potentially be affected by proposed federal projects. The National
Historic Preservation Act (NHPA) of 1966 (as amended) is the cornerstone
of federal preservation law and establishes the current national
historic preservation program. Section 106 of the NHPA requires federal
agencies to consider the effects of their actions on historic properties
and to seek comments from the Advisory Council on Historic Preservation
(ACHP). The procedure for meeting Section 106 requirements is set forth
in ACHP regulations at 36 CFR Part 800. Other statutes and regulations
include: the Antiquities Act of 1906, Section 4(f) of the DOT Act of
1966, the Archaeological and Historic Preservation Act of 1974, the
American Indian Religious Freedom Act of 1978 (as amended), the
Archaeological Resources Protection Act of 1979 (as amended), the Native
American Graves Protection and Repatriation Act of 1990, Section
101(d)(6)(A) and (B) of the NHPA, and other codes, plans, and programs
that set forth actions and procedures for the protection of cultural
resources.

Cultural resources derive their significance from the roles they have
played in American history, architecture, archaeology, engineering, and
culture. To be eligible for listing on the NRHP, resources must be
evaluated for significance against standards established by the NPS. The
criteria for evaluation listed below are those standards used for
evaluating NRHP eligibility. The quality of significance is "present in
districts, sites, buildings, structures, and objects\
that . . .:

(a) are associated with events that have made a significant contribution
    to the broad patterns of our history; or

(b) are associated with the lives of persons significant in our past; or

(c) embody the distinctive characteristics of a type, period, or method
    of construction, or that represent the work of master, or that
    possess high artistic values, or that represent a significant and
    distinguishable entity whose components may lack individual
    distinction; or

(d) have yielded, or may be likely to yield information important in
    prehistory or history"

(NPS, 1982).

To be eligible for listing on the NRHP, a property must meet at least
one of the above criteria and possess "integrity of location, design,
setting, materials, workmanship, feeling, and association. . ." (NPS,
1982). NRHP eligibility is determined in consultation with the SHPO.

Potential impacts to significant cultural resources occur when the
proposed undertaking alters the characteristics of the resource that
qualifies the resource for inclusion on the NRHP. To determine effect,
potential alteration to features of a property's location, setting, or
use should be considered. An undertaking is considered to have an
adverse effect when the integrity of the property's location, design,
setting, materials, workmanship, feeling, or association is diminished.
Potential adverse effects include:

-   physical destruction, damage, or alteration of all or part of the
    property;

-   isolation of the property from or alteration of the character of the
    property's setting when that character contributes to the property's
    qualification for the National Register;

-   introduction of visual, audible, or atmospheric elements that are
    out of character with the property or alter its setting;

-   neglect of a property resulting in its deterioration or destruction;
    and

-   transfer, lease, or sale of the property

(ACHP and GSA, 1991).

## recreation

### Resources Affected

Recreational resources include designated areas such as national and
state parks, national and state recreation areas, national seashores,
national monuments, national historic sites, state beaches, and state
fishing areas. Other recreational resources potentially affected by
construction and operation of the proposed facilities are regional,
county, and municipal parks, reservoirs and beaches, and recreation
areas used by the local populace. Potential concerns in these areas
include increases in traffic and noise, alteration of scenic quality,
increased access from the installation of new roadways, and conversion
of land uses to nonrecreational uses, both individually and
cumulatively.

Recreational resources are those places or amenities set aside as
parklands, beaches, trails (hiking, skiing, bicycling, equestrian),
recreation fields, sport or recreational venues, open spaces,
aesthetically pleasing landscapes, and many other locales. National,
state, and local jurisdictions typically have designated land areas with
defined boundaries for recreation. Other less structured
activities---for example, hunting or cross-country skiing---are
performed in broad, less defined locales. A recreational setting may
consist of natural or man-made landscapes and can vary in size from a
roadside monument to a multimillion-acre wilderness area.

### Data Sources

Key national recreational resources can be identified from land-use maps
prepared by numerous federal agencies, such as the NPS, USFS, BLM,
USFWS, and other land management agencies. State recreational resources
are found from state park, recreation, natural resource, fish and game,
and historic preservation agencies. Local regional or county
recreational amenities are found from maps prepared by the local
governing jurisdiction, and local civic and athletic organizations.

### Regulatory Setting

Recreational resources are provided varying levels of management and
protection by several federal regulations. These include Section 4(f) of
the DOT Act, the Land and Water Conservation Act of 1985 (36 CFR Part
59), the Wilderness Act of 1964, the Coastal Zone Management Act, the
Wild and Scenic Rivers Act, and portions of other legislation enacted to
create and maintain the resource areas mentioned in Section 5.9.1.

## land use 

### Resources Affected

Natural land uses and land uses that occur as a result of human
modification are considered affected resources. Natural land uses may
include forest, rangeland, desert, and other open or undeveloped areas.
Human land uses include residential, commercial, industrial, and
institutional, transportation corridors, communications and utilities
rights-of-way, agriculture, and other activities. Recreational land use
and wild and scenic rivers are addressed separately in Section 5.9,
Recreational Resources, and Section 5.6, Visual Resources.

Land-use designations are typically made by the state or federal land
management agency or by the local jurisdiction through management plans,
policies, ordinances, and regulations. Federal policies that govern
prime farmlands and coastal zones include the Farmland Protection Policy
Act of 1984 (FPPA) (7 CFR 658) and the Coastal Zone Management Act
(CZMA) of 1972 (as amended) (15 CFR 923). Prime farmland is land that
has the best combination of physical and chemical characteristics for
the production of crops. The FPPA minimizes the extent to which federal
programs contribute to the unnecessary and irreversible conversion of
such farmlands to nonagricultural uses, and assures that federal
programs are administered to be compatible with state or local
governments and policies to protect farmland. Approximately 334 million
acres of land in the U.S. are designated as prime farmland by the U.S.
Department of Agriculture (USDA) (NRCS, 1994). Prime farmlands can occur
throughout the U.S. but are more prevalent throughout the Great Plains,
Midwest, and Western states.

Coastal zones are areas located along U.S. oceans and lakes that are
regulated by state or local management plans developed under the
authority of the CZMA. Coastal zone areas include islands, transitional
and intertidal areas, salt marshes, wetlands, beaches, estuaries, bays,
ponds, lagoons, bayous, dunes, barrier islands, reefs, and fish and
wildlife habitat. The purpose of the act is to preserve, protect,
develop, and restore or enhance the resources of the nation's coastal
zones, and to assure that all federally supported activities that
directly affect the coastal zone are consistent with approved state
coastal management programs as much as possible.

Land-use designations are typically more restrictive in urban and
suburban areas and can change frequently over a distance of just several
hundreds of feet. Conversely, in rural areas, a single land-use
designation may encompass several tens of acres, or more. These areas
are typically zoned for agriculture and carry relatively few
restrictions on the installation of communication towers, unmanned
shelters, and the extension of utilities. However, because of the
proliferation of numerous cellular and other communication antenna
towers in urban, suburban, rural, and transitional landscapes, more
stringent land-use approval procedures are becoming common.

The NDGPS program will require the long-term lease or acquisition of
public or private lands to install towers and equipment within an
approximately 11-acre area. A major issue is the potential for
regulatory conflict between existing land uses and the proposed NDGPS
action. Under the doctrine of federal supremacy, the federal government
is not subject to local or state land-use and zoning regulations unless
specifically consented to by Congress. Under the Public Building
Amendments of 1988, the federal government does take land-use and zoning
policies into consideration, and cooperates with state and local
agencies to avoid conflicts when possible. The federal government will
offer planning and design drawings for courtesy review, but will not
formally apply for conditional use permits, variances, or similar
land-use approvals related to local/regional zoning and land-use law.

### Data Sources

Individual city and county planning agencies or regional planning boards
are the most definitive sources of information regarding current
land-use plans and zoning regulations. Lead planners can provide an
indication of the potential for current and future land use. State
agencies coordinating or assisting in regional development plans can
also provide information on proposed development activities. State
and/or local agencies would also provide coastal zone management
policies approved under the CZMA. NRCS soil surveys and separate soil
listings delineate areas that may qualify as prime farmland.

### Regulatory Setting

The Public Buildings Act of 1959 enables federal projects to proceed
without local approvals. The Public Building Amendments of 1988 require
federal agencies to consider local land use and zoning during their
project planning and to accommodate local requirements whenever
possible.

Executive Order 12372---*Intergovernmental Review of Federal Programs*
directs federal agencies to "make efforts to accommodate state and local
elected officials' concerns with proposed...direct federal development."
This executive order requires federal agencies to provide state and
local officials the opportunity to comment on action that could affect
their jurisdictions, using state clearinghouses to facilitate the
consultation process, when possible. Several states have elected to
eliminate this process; however, efforts to coordinate with local
planning and development reviewing agencies should be made at the
earliest possible time.

The Land and Water Conservation Act of 1965 promulgated under 36 CFR
Part 59 allows Congress to fund grants to state and local agencies for
the acquisition of parkland. Agencies may purchase and develop land and
water areas for recreational use with those funds but may not use the
land for nonpark uses. The CZMA and FPPA are discussed above. Section
4(f) of the DOT Act states that a DOT action requiring the use of any
publicly owned land from a public park, recreation area, or wildlife and
waterfowl refuge of national, state, or local significance or land from
a historic site of national, state, or local significance would only be
approved if there is no feasible and prudent alternative to the use of
such land, or the action includes all possible planning to minimize harm
resulting from the use.

Other federal laws contain indirect land-use elements. The Federal Land
Policy and Management Act of 1976 (as amended) requires projects on BLM
land to coordinate with state and local land-use plans. The Federal
Aviation Act of 1958 provides for FAA review of proposed towers over 200
ft, and smaller towers within 20,000 ft of major airport runways or
within 10,000 ft of general aviation airports. This process is carried
out through the review of FAA Form 7460-1---Notice of Proposed
Construction or Alteration. Federal and state environmental regulations
or programs mentioned in other sections of this document could prohibit
development in some areas. Or, these regulations may not prohibit
development, but could require extensive mitigation to protect or
replace a particular resource. Also, local concerns may arise because of
perceived conflicts between the project and existing land-use plans,
zoning, and other development controls.

## socioeconomics and Environmental justice

### Resources Affected

Socioeconomics comprise such interrelated resources as population,
employment, income, temporary living quarters (during construction), and
public finance. Public finance pertains to the fiscal effect of a
project on local governments---including such entities as counties,
cities, schools, and special districts---and refers to local property
revenues, expenditures, debt, and bonding and tax limitations.
Socioeconomic issues and concerns are associated with a project's
selection and use of construction contractors, available local labor and
materials; the need for temporary housing and other services to support
construction and maintenance personnel; the need for protective or
public services, such as fire and police protection; and any special tax
ramifications. Land use as applied to social and economic issues and
concerns is addressed in Section 5.10.

Executive Order 12898---*Federal Actions to Address Environmental
Justice in Minority Populations and Low-Income Populations,* was issued
to ensure that disproportionately high and adverse human health or
environmental effects on ethnic minority communities and low-income
communities were identified and addressed (President, 1994). An ethnic
minority is defined as an individual who is a member of one of the
following population groups: American Indian or Native Alaskan, Asian or
Pacific islander, Black (not of Hispanic origin), or Hispanic. Ethnic
minority populations are identified when the minority population of a
defined study area, or area of project effect, exceeds 50 percent, or
the minority population percentage is meaningfully greater when compared
with levels in other geographically defined units (e.g., neighborhoods,
census tracts, county, state) (CEQ, 1997). Low-income populations are
identified as those living at or below statistical poverty thresholds.
Impacts on resource areas such as water and air quality could
potentially be considered adverse to minority and low-income populations
if they were found to significantly impact the environment. Executive
Order 13045---*Protection of Children from Environmental Health Risks
and Safety Risks*, addresses safety risks to children that may result
from federal activities and requires each federal agency, when taking
regulatory action, to identify and assess environmental health risks
that may disproportionately affect children (President, 1997).

### Data Sources

Demographic data such as area population, ethnic minority status, and
income are available from the Bureau of the Census, as well as from
federal, tribal, state, and local health, environmental, and economic
agencies. Local employment and industry summaries prepared by local
jurisdictions or the Chamber of Commerce, the county tax assessor's
office, and listings of local construction contractors and existing
hotel/motel accommodations should be examined.

### Regulatory Setting

Executive Order 12898 requires federal agencies to identify and address
disproportionately high and adverse human health or environmental
effects of their programs and activities on minority communities and
low-income populations. The CEQ Interagency Working Group, chaired by
the EPA, finalized guidelines for incorporating environmental justice
concerns into the NEPA compliance process in December 1997. DOT
procedures to comply with Executive Order 12898 are set forth in the
final DOT order issued on April 15, 1997, to address environmental
justice (*Federal Register*, April 15, 1997). Executive Order 13045
provides policy guidance for possible effects on children from federal
activities (President, 1997).

## energy

### Resources Affected

Direct and indirect energy sources required for the installation and
operation of each of the proposed NDGPS reference stations are
considered. Direct energy sources include 3-phase electrical power from
commercially available sources and fuels required to operate the NDGPS
equipment, and construction and maintenance vehicles and equipment.
Indirect energy sources are fuel resources consumed by others because of
NDGPS installation and operation.

Public and cooperative energy providers are typically able to provide
service in even remote areas throughout the continental U.S. Depending
on the location, primary sources of energy may not be available for
proposed NDGPS site locations in Alaska. Adequate fuel supplies for
transportation and equipment are expected to be present in most areas.

Backup power will be provided by a BUPG equivalent to the same as the
existing units serving the USAF GWEN facilities.

### Data Sources

Site-specific information regarding available 3-phase power sources and
their current service areas are available from the local electric power
company. Some local government offices may also have this information.

### Regulatory Setting

Specific state or local regulations may require consideration of energy
expenditures and the availability of energy resources.

## HAZARDOUS MATERIALS

### Physical Setting

The reuse of existing GWEN relay node properties is contemplated by
several of the alternative actions considered herein. In general, these
facilities would be expected to contain minimal amounts of hazardous or
regulated materials. During construction and maintenance of the GWEN
facilities, it is likely that hazardous or regulated materials, such as
petroleum fuels, paints, solvents and cleaners, sealants, herbicides and
pesticides, and so on, were used in small quantities. However, it is
unlikely that the use of small amounts of those materials would have
resulted in significant contamination of the property. Diesel fuel for
the GWEN backup generator was stored at these properties in tanks with
secondary containment, which should have prevented release of fuel and
contamination of soil or groundwater.

The GWEN relay nodes were installed after the manufacture of
polychlorinated biphenyls (PCBs) was banned, and it is unlikely that
transformers or light ballasts at these facilities would contain PCBs.
Use of lead paint in occupied structures was banned prior to
construction of the GWEN relay nodes, and it is expected that lead paint
would not have been used at the relay nodes (USAF, 1995). Similarly,
because of the relatively recent construction of the GWEN relay nodes in
the late 1980s or early 1990s, these facilities are not expected to
contain asbestos (USAF, 1995).

The GWEN copper ground plane is composed of unshielded copper wire and
may have corroded during the years since its installation. If so, it is
possible that the level of copper in soil or groundwater at the GWEN
property may have reached action levels of regulatory significance.
According to the GWEN Final EIS, that result is only possible in areas
of acidic soil and constantly or seasonally shallow groundwater. For the
most part, such areas were avoided during selection of locations for
GWEN relay nodes, thus significant levels of copper in soil or
groundwater is considered unlikely at GWEN properties. Recent tests of
four soil samples taken at depths of 1 to 3 ft below the ground surface
at the GWEN relay node at Savannah Beach, Georgia, which has acidic
soils and may be subject to a seasonally shallow water table, found
copper levels ranging up to 11 ppm. The measured copper levels are far
below the 1,500 ppm action level for copper in soil established by the
Georgia Department of Natural Resources (EMC Engineering Services, Inc.,
August 21, 1998).

### Regulatory Setting

The Resource Conservation and Recovery Act of 1976 governs the handling,
treatment, and disposal of solid wastes, which are defined as garbage,
refuse, or sludge from a waste treatment facility and other discarded
materials including solids, semi-solids, liquids, and contained gases.
In general, land disposal of solid wastes is allowed only at properly
permitted facilities which are located, constructed, and operated so as
to prevent release of contaminants to the environment. Hazardous wastes
are those solid wastes which are hazardous to human health or the
environment because of an inherent characteristic of being reactive,
ignitable, corrosive, or toxic. Petroleum products are not considered
hazardous materials or wastes but their storage, transport, use, and
disposal is regulated by several laws, most notably the Oil Pollution
Act of 1990.

The Comprehensive Environmental Response, Compensation, and Liability
Act assigns physical and fiscal responsibility for the removal or
neutralization of hazardous waste. In general, the owner and operator of
facilities or land at the time at which disposal of hazardous waste
occurs is responsible for the cost of remedial actions. In some
situations, such as when the prior owner or operator cannot be found or
is financially insolvent, landowners who acquire a property with
pre-existing contamination may be liable for clean-up costs. Landowners
in the latter situation can be relieved of liability if they can show
that they diligently conducted studies to ascertain the presence or
absence of contamination prior to acquiring the property (i.e., the
innocent landowner defense). The most common means for establishing this
defense is to conduct an environmental due diligence study meeting
recognized standards, such as the American Society of Testing and
Materials (ASTM) E-1527-93 or E-1528-93 standards. Compliance with the
ASTM due diligence standards requires investigation of past and existing
uses of the target property, past and existing uses of nearby
properties, search of government and private environmental databases for
information on the target property and surrounding lands, physical
inspection of the property and surroundings, and interview of
individuals who may have knowledge about the target property and its
past and present uses.

Under regulations contained in 40 CFR 112, newly installed storage tanks
for fuel must meet certain performance standards including designs to
minimize the likelihood of releases of fuel to the environment (e.g.,
double walls, secondary containment structures). In addition, a Spill
Prevention, Control, and Countermeasure (SPCC) Plan must be prepared for
facilities containing an individual above-ground storage tank with
capacity of 660 gallons or more or multiple above-ground tanks with a
total capacity of 1,320 gallons or more.

## Radiofrequency Environment and Human Exposure

The Communications Act of 1934 assigns responsibility for assignment of
radio frequencies for non-government users to the Federal Communications
Commission (FCC) and for government users to the President. Executive
Order 12046 (March 26, 1978) delegated the President's authority over
government radio users to Secretary of Commerce who designated the
Administrator of NTIA as the appropriate party to carry out this
function. NDGPS reference stations would be government radio stations
and would require a frequency allocation from the NTIA.

NDGPS reference stations include two receiving antennas for GPS signals
and an antenna transmitting the DGPS correction signal. The receive
antennas are mounted on twin masts at heights of about 30 ft above
ground level (AGL). Under the preferred alternative, the transmit
antenna typically consists of a 299 ft-tall steel lattice tower, similar
to amplitude modulated (AM) broadcast towers commonly found throughout
the U.S. At former GWEN sites, the existing transmit tower and antennas
would be reused, and the GPS receive antennas and masts would be newly
installed. The receive antennas only receive the existing GPS signals
emitted by satellites in earth orbit; they do not generate any new RF
emissions or add to the existing RF environment. The band between 285
and 315 kHz, which includes the operating frequencies of the NDGPS
transmitters, is reserved for use in the Western Hemisphere (i.e.,
north, central, and south America) for maritime radiolocation and
aeronautical radionavigation. DGPS stations are expressly authorized to
operate in this band on a primary basis. In this band, the FCC may
authorize operation by specific nongovernment navigation aids based on
need and a lack of government service. Radio frequency separation is
attained by following the *Manual of Regulations and Procedures for
Radio Frequency Management* (DOC NTIA, 1994). Additionally, government
and nongovernment electric utility providers can operate power line
carrier communications systems, which are transmitted along power lines,
at frequencies below 490 kHz (NTIA, 1995).

In 1991, the FCC and the EPA measured the electric and magnetic fields
at 1 m (3.28 ft) AGL at various locations near nine AM broadcast
antennas in southern California. The towers ranged in height from 180 to
480 ft, which is comparable to the roughly 299 ft tower planned at a
typical NDGPS reference station. The power levels of the transmissions
from these towers ranged from 630 W to 50 kW, as compared with the 300 W
to 500 W broadcast by the typical NDGPS reference station. Within 1 m of
the base of these towers, the measured electric field ranged from 95 to
500 V/m. At a distance of 164 ft (50 m) from the base of the towers, the
electric field had diminished considerably and ranged from 2.5 to 30
V/m. At a distance of 328 ft (100 m), the strength of the electric field
ranged from 3.3 to 20 V/m. The local strength of the measured electric
field was substantially reduced in the vicinity of conductive objects,
such as a metal fence. The strength of the magnetic field measured at
the base of the towers ranged from 0.1 to 1.5 A/m. At a distance of 164
ft (50 m), the strength of the magnetic field decreased considerably and
ranged from 0.01 to 0.08 A/m. At a distance of 328 ft (100 m), the
strength of the magnetic field ranged from 0.008 to 0.075 A/m.

The GWEN relay nodes that are proposed for conversion to NDGPS reference
stations contain two types of radio transmitters, a 50 W transmitter
operating in the 225 to 400 MHz band and a 5,000 W transmitter operating
in the 150 to 175 kHz band. These transmitters would be removed during
the conversion for NDGPS use. The Final EIS for the GWEN system examined
the possible human health effects of exposure to the radio signals
transmitted by the GWEN relay nodes. Possible effects of exposure to
GWEN transmissions in the 150 to 175 kHz band, which is relatively close
to the 300 kHz operating frequency of NDGPS, are of particular interest.
The GWEN Final EIS found that the level of exposure to RF emissions
during operation of GWEN relay nodes would comply with national and
international safety guidelines (USAF, 1987). In 1993, at the request of
the USAF, the National Research Council (NRC) of the National Academy of
Sciences reviewed the findings of the GWEN Final EIS with respect to
human exposure to RF fields. The NRC study investigated possible
mechanisms of interactions between the GWEN fields and biological
tissues and organisms; possible effects on cells and cellular
components, organs, and tissue systems; and evidence from
epidemiological studies and laboratory studies on animals and human
volunteers. The NRC states, "The conclusions of this report reinforce
those of the EIS, in that no evidence of adverse effects of GWEN fields
on public health was found" (NRC, 1993).

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# environmental consequences

This section provides a programmatic-level analysis of the environmental
impacts (individual as well as cumulative) that could occur in specific
issue areas as a result of implementation of the preferred action and
alternatives. The general approach is to identify the impact and take
specific mitigation measures that would reduce potential impacts below a
level of significance. The following mitigation strategies are used in
the order shown:

-   Avoiding the impact altogether by not undertaking the action or
    parts of the action

-   Minimizing the impact by limiting the degree or magnitude of the
    action and its implementation

-   Rectifying the impact by repairing, rehabilitating, or restoring the
    affected environment

-   Reducing or eliminating the impact over time by preservation and
    maintenance operations during the life of the action

-   Compensating for the impact by replacing or providing substitute
    resources or environments

It is the government's intention to avoid impacts to sensitive
environmental conditions or resources through selection of locations for
NDGPS reference stations. During the site-selection process, the
presence or absence of sensitive environmental resources in the siting
area will be ascertained. Sites for reference stations will be selected
such that the proposed facilities will be compatible with nearby uses
and will not cause adverse effects on environmental resources. For
environmental impacts that cannot be avoided, specific mitigation will
be performed to ensure an impact is less than significant. If for some
unforeseeable reason planned mitigation measures cannot be undertaken,
additional environmental analysis and documentation may be prepared by
the FHWA.

The broadest range of anticipated environmental impacts are identified
for each environmental resource/condition and project alternative.
Information is presented to determine, at the programmatic level,
whether the potential impact to the human environment will be
significant or not significant.

The proposed NDGPS network of reference stations will consist of reuse
of existing GWEN sites and/or equipment, and deployment of similar
equipment at new sites. For that reason, information in the GWEN Final
EIS has been used in this section when appropriate.

## Geology

### Alternative A (Preferred Action)---Mix of GWEN sites and equipment plus new sites and equipment

Seismic shaking because of an earthquake could damage the proposed
facilities. The GWEN towers, whether existing or transferred to a new
location, are stabilized by guy wires. A very large earthquake could
potentially result in damage on-site to the NDGPS transmission tower and
associated facilities. The existing towers have been in place for many
years without failure, indicating significant structural integrity. Even
in the case of collapse, the tower would remain within the property
boundary and there would be no impact on surrounding areas. On-site
environmental impact would not be significant since GWEN sites were
selected that do not contain environmental resources of critical concern
and none are expected to have developed during the operation of GWEN. In
the case of tower failure, it is expected that severely damaged towers
would be replaced with new DGPS equipment by the USCG Maintenance and
Logistics Command. The proposed 11 ft × 17 ft shelter at the base of the
tower would be designed and constructed to withstand seismic shaking
that may occur in seismic zone 4 (great damage) conditions.

Since ground-clearing activities are involved at new sites, the
potential for erosion is highest during facility construction and
decommissioning. Minimal ground disturbance is required for the
conversion of GWEN sites to NDGPS reference stations. Because GWEN sites
are located on relatively level terrain and only small areas of soil
would be disturbed, erosion is not expected as a result of NDGPS
equipment installation on those properties. The potential for
significant impacts from soil erosion at new locations will be minimal
since preferred locations for reference stations have relatively level
terrain and are not located close to large drainage systems. Unless
eroded or highly erodible soil is present at a new site area, the only
erosion impacts would be insignificant. To reduce the effects of
erosion, standard erosion control measures will be used, if feasible.
These include the use of silt fences, mulch, siltation basins, and
revegetation of disturbed areas to control short-term erosion. Steep
slopes and eroded or highly erodible areas identified in NRCS soil
surveys will be avoided during the selection of new NDGPS sites.

Mineral resources occur in widely spaced and diverse areas. Selection of
new NDGPS sites will avoid areas of mineral extraction and known
economic mineral sources. If avoiding these resources is not possible,
it is unlikely that the small size of the proposed facilities, about 11
acres, would significantly restrict access to mineral deposits. No
impacts on mineral resources would result from conversion of GWEN
properties to NDGPS use.

Paleontological resources are found in widely scattered areas. The
likelihood of encountering these resources is very low, and the resource
can be avoided during selection of new sites for NDGPS reference
stations through early consultation with the state geologist and other
relevant agencies. For federal properties in certain fossil-rich areas,
paleontological resource monitoring during construction may be prudent.
Inquiries to the state geologist regarding known paleontological
resources are recommended when evaluating sites on undeveloped property.
If the resource is encountered, the impact is likely to be minor
provided that monitoring is performed whenever recommended by the state
geologist. Extraction and recordation of the resource will be conducted,
if feasible, should unforeseeable potentially significant impacts to
paleontological resources arise. No significant impacts to geological or
mineral resources will result.

### Alternative B---Mix of GWEN sites and new sites using new equipment

The use of new equipment instead of using GWEN equipment transferred
from other locations would result in essentially the same effects on
geological resources as discussed in Alternative A. Using a new USCG
tower structure rather than a previously used GWEN tower may slightly
reduce the potential for structural failure during seismic activity (or
high wind loads); however, the potential for this impact to occur is
remote. All other impacts are expected to be equivalent to Alternative
A, discussed above. No significant impacts to geological or mineral
resources will result.

### Alternative C---All new sites using USCG-like equipment

Under this alternative, all NDGPS reference station sites will be
located at new non-GWEN sites less than 11 acres. Furthermore, up to 35
more reference stations would be required than for Alternatives A and B.
This alternative has the most potential for impacts because of the
greater number of reference stations required and the expected location
of reference stations on previously undeveloped property. While it is
more likely that geological resources would be encountered under this
alternative, avoiding significant geological hazards and resources will
be possible. Mitigation measures discussed under Alternative A would
reduce potential impacts to insignificant levels. No significant impacts
to geological or mineral resources will result.

### Alternative D---No-action alternative

The no-action alternative would not result in the impact on geological
and mineral resources expected from implementation of the proposed NDGPS
service. Decommissioned GWEN facilities would be dismantled and removed
by the USAF. GWEN site leases with private landowners or land-use
agreements with other federal land managers would be terminated. This
USAF action would involve removal of existing facilities and would be
confined to previously disturbed areas. No significant impacts to
geological or mineral resources will result.

## water quality

### Alternative A (Preferred Action)---Mix of GWEN sites and equipment plus new sites and equipment

Water resources may be affected by the proposed NDGPS facilities because
of soil erosion promoted by land clearing and grading during
construction, and subsequent entertainment and transport of eroded soil
to surface waters. Also of interest is the potential for copper from the
ground plane to leach over time into the soil or to the nearest surface
water or groundwater. Improper storage and handling of fuels for each
proposed BUPG may also result in release to the environment and
contamination of water resources.

The potential for copper from the NDGPS ground plane to enter water
supplies depends on the rate of corrosion, the extent of leaching into
the soil, and the distance for transport of copper via groundwater flow
to the nearest water resource. The Final EIS for the GWEN Final
Operational Capacity found that the rate of copper addition from a
single ground plane to nonacidic, unsaturated soil would normally be
less than 10 pounds per year and less than 1 pound per acre. The maximum
rate of copper added to soil is estimated at 4.75 pounds per acre per
year. This amount would not be expected to have adverse effects on water
resources or on terrestrial or aquatic ecosystems. Ground planes at new
NDGPS reference station locations would be very similar to the GWEN
ground plane. No significant impact upon drinking water is expected for
sites with nonacidic soils or that are not subject to seasonal
saturation.

The mobility of copper in soil is relatively limited, except in acidic
soils (pH less than 6.5) and where the seasonally high water table is
within 1.3 m of the ground plane. During the selection of new NDGPS
sites, it would be prudent to avoid locations that have both of these
conditions; if these conditions are avoided, no significant impact in
water quality would result. If these conditions cannot be avoided, a
separation of 300 ft between the ground plane and the nearest surface
water source (particularly those that support significant aquatic fauna)
is planned. With that separation, the impact to water quality would not
be significant. If under these conditions a 300 ft setback from surface
water resources cannot be established, there exists the potential for
significant impact to water resources containing sensitive aquatic
organisms. A possible mitigation under these unlikely circumstances
would be the application of lime to soil at the ground plane in order to
raise the soil pH above 6.5. Unless the background copper concentration
of the soil is known to be excessively high, no cumulative impacts would
result.

There is potential for soil erosion at new NDGPS sites because of the
installation of facilities on previously undeveloped land. Although the
total site area would be about 11 acres, less than 8 acres would
actually be cleared and disturbed. Construction would remove existing
vegetation and organic soil horizons that normally limit erosion of
soil. The potential for severe erosion from land-disturbing activities
and the potential for impacts to water resources would be eliminated by
avoiding eroded or highly erodible soils as identified by the NRCS soil
survey, or by evaluating conditions and taking appropriate erosion
control measures based on consultation with the local NRCS soil
scientist. Erosive soils will be avoided during site selection, or, if
avoidance is not possible, measures will be taken to prevent washing of
soil and increased turbidity of surface waters. No significant impacts
upon local water quality would result.

The converted GWEN sites and the newly constructed NDGPS reference
stations would have aboveground storage tanks (ASTs) for diesel fuel for
the standby generators. At converted GWEN sites, 1,000 gallons of
storage capacity is available. At new sites, 500 gallons of capacity
would be installed. EPA regulations at 40 CFR 112 require preparation of
SPCC plans for storage of more than 660 gallons in a single AST or more
than 1,320 gallons in multiple ASTs at a single facility. The proposed
NDGPS reference stations would not have capacity exceeding those
thresholds and preparation of an SPCC would not be required. The ASTs
for the reference stations would have secondary containment to prevent
release of fuel to the environment. No significant impacts on water
quality would result.

### Alternative B---Mix of GWEN sites and new sites using new equipment

The installation of USCG-like equipment at new NDGPS sites, instead of
transferring decommissioned GWEN equipment, would not be expected to
alter the anticipated level of impact to water resources described for
Alternative A. The physical specifications and site-selection criteria
would essentially be equivalent for Alternatives A and B. No significant
impacts on water quality would result.

### Alternative C---All new sites using USCG-like equipment

Under Alternative C, individual NDGPS sites are likely to be smaller in
size (and broadcast coverage area). For this reason, additional sites
would be required nationwide, and the ability to avoid certain locales
with sloped terrain, acidic or highly erodible soil, or areas within 300
ft of a surface water body may decrease. Under this alternative, there
is a slightly higher potential for impacts to water resources because of
the greater number of reference stations. Mitigation measures mentioned
above for Alternative A for impacts to water resources apply for this
alternative action. Potentially significant impacts can be avoided or
mitigated under this alternative. Because of the smaller size of each
project area, cumulative effects to water resources when combined with
other nearby land uses will be negligible. No significant impacts on
water quality would result.

### Alternative D---No-action alternative

The no-action alternative would prevent the occurrence of water resource
impacts that may result from the installation of NDGPS reference
stations. Water quality would remain unchanged.

Potential indirect environmental benefits provided by the proposed NDGPS
service would not occur. These include increased accuracy in the
positioning of water sample collection points and greater precision when
applying fertilizers and pesticides, minimizing adverse impact on
adjacent water resources. No improvement in water quality would result
under the no-action alternative. Other local area positioning methods
may be able to substitute for NDGPS and provide benefits to water
resources.

Under this alternative GWEN facilities would be dismantled and removed
after decommissioning. This activity would not affect water resources.
No significant impact on water quality would result under the no-action
alternative.

## ecologically sensitive areas

### Alternative A (Preferred Action)---Mix of GWEN sites and equipment plus new sites and equipment

Ecologically sensitive areas contain resources that are particularly
susceptible to impacts from new development. Of specific regulatory
concern are wetlands and floodplain resources. A site-specific wetlands
delineation survey may be required to determine whether jurisdictional
wetlands would be affected. Areas with hydric soil, hydrophylic
vegetation, and seasonally standing water meet the criteria for
jurisdictional wetlands. Projects resulting in dredge or fill deposition
into wetlands would require a nationwide or individual permit from the
USACE, in accordance with Section 404 of the Clean Water Act. To obtain
a USACE permit, it must be demonstrated that no upland site alternatives
are feasible. Nationwide permits are available in some states for
relatively small actions, such as road crossings, utility corridors, and
relatively small land disturbing activities (i.e., less than 10 acres)
and may apply to NDGPS reference stations where available.

Wetlands will be avoided when selecting prospective sites for NDGPS
reference stations. Wetland inventory maps prepared by the USFWS can be
used to identify known wetlands resources. Avoiding areas containing
hydric soil, as identified by the NRCS, will eliminate conflicts with
suspected wetlands resources. If jurisdictional wetlands are present, a
delineation survey will be performed and, if necessary, nationwide or
individual permits for dredge and fill in wetlands will be obtained from
the USACE. For developments that require an individual USACE permit for
dredge or fill in wetlands, mitigation may be necessary. These may
include the enhancement or creation of wetlands on other portions of the
property or in designated areas off-site. Some states offer the
mitigation option of contributing restoration funds to a "wetlands
bank." It is the intention of the FHWA and participating agencies to
first avoid jurisdictional wetlands. If avoidance is not feasible, the
impact will be rendered to an insignificant level by minimizing the
affected area and performing mitigation measures agreed upon by the FHWA
and the USACE during Section 404 permit process. Since either resource
avoidance or appropriate mitigation (pursuant to a USACE permit) will be
achieved, no significant impacts will result.

Similarly, developments involving placement of new dwellings or assets
must be outside of the 100-year floodplain, as designated by the FEMA
(unless no reasonable alternative exists). FEMA Flood Insurance Rate
Maps identify these areas. If no other alternative exists, the ground
elevation for the proposed facilities must be raised above the 100-year
floodplain to protect life and property, or critical facilities must be
floodproofed. For the NDGPS program, this would include the equipment
shelters, BUPG unit, and transmit and receive antenna towers. Unless
unforeseeable circumstances arise, the 100-year floodplain will be
avoided during the siting process for each NDGPS reference station.

No significant impacts will result.

### Alternative B---Mix of GWEN sites and new sites using new equipment

For Alternative B, the installation of new equipment at newly proposed
NDGPS sites (instead of transferring decommissioned GWEN equipment)
would have an equivalent level of impact to environmentally sensitive
resources as anticipated under Alternative A. The physical
specifications and site-selection criteria under this alternative are
equivalent to those for Alternative A. No significant impacts will
result.

### Alternative C---All new sites using USCG-like equipment

Under Alternative C, a greater number of NDGPS reference stations would
be required nationwide and the ability to avoid some environmentally
sensitive locales could decrease. Under this alternative, there is a
slightly greater likelihood that environmentally sensitive resources
could not be avoided during the siting process. Mitigation measures
mentioned above for Alternative A for impacts to environmentally
sensitive resources would apply for this alternative action. Because of
the relatively small size of each project area, nationwide dredge and
fill permits from the USACE are likely to be appropriate in the unlikely
case that jurisdictional wetlands are affected. In general, significant
impacts to environmentally sensitive resources under this alternative
will be avoided during site selection or by applying mitigation
measures. No significant impacts will result.

### Alternative D---No-action alternative

The no-action alternative would not result in resource impacts
anticipated to result from the implementation of the proposed NDGPS
service. Environmentally sensitive resources would remain unchanged.
Enhancements in water (wetland) quality monitoring methods expected to
result from an NDGPS would not be realized. Decommissioned GWEN
facilities would be dismantled and removed. Based on the siting criteria
identified in the GWEN Final EIS and applied during GWEN site selection,
no sensitive water resources are expected to be affected. No significant
impact upon this resource will result during GWEN decommissioning.

## air quality

### Alternative A (Preferred Action)---Mix of GWEN sites and equipment plus new sites and equipment

For this resource, short-term impacts are associated with
construction-related air emissions. Long-term impacts are associated
with operation and maintenance activities, such as use of the BUPG
diesel generator, and project-related vehicle emissions. Most
construction-related emissions are exempt from regulatory review
provided that NAAQS would not be exceeded. For the NDGPS program,
qualitative (versus quantitative air quality) modeling is sufficient to
demonstrate continued adherence to air quality standards. The
construction period for the conversion of GWEN sites will last between 4
and 6 weeks and the installation of equipment at new sites approximately
2 and 3 months. Except for dust, emission of criteria pollutants by
project-related vehicles and equipment during the construction period
will be minor. Changes in local air quality resulting from these sources
would not be a significant impact. Cumulative effects would also not be
significant.

During installation of the ground plane and guy-wire anchors at new
sites, ground surface disturbance will occur over approximately
three-quarters of the 11-acre site. In areas where wind erosion is a
concern, dust suppression techniques (e.g., periodic watering or using
low-impact ditching equipment) will be used as necessary to reduce
airborne emissions. Dust emissions would not result from the conversion
of GWEN sites to NDGPS reference stations.

NDGPS reference stations would not be classified as major emission
sources. The emission of minor amounts of air pollution would be
unavoidable; however, the individual and cumulative impacts during
construction will be insignificant. Long-term impacts from hydrocarbon
(HC) and oxides of nitrogen (NO~x~) emissions during monthly testing and
infrequent use of the BUPG and from quarterly equipment maintenance
visits will be negligible. For each NDGPS reference station in a
nonattainment area, the FHWA will adhere to the approved applicable
State Implementation Plan (SIP). In some areas, a local permit to
construct and/or operate a BUPG is required. In these cases, the FHWA
will ensure that necessary permits are obtained by the operator of a
reference station. No hazardous air pollutants specifically listed in
the Clean Air Act Amendments (42 USC 7412) will be generated by the
proposed facilities. No significant impacts on air quality will result.

### Alternative B---Mix of GWEN sites and new sites using new equipment

The level of local air quality impacts resulting from the construction
and operation of NDGPS reference stations using USCG-like equipment at
new sites will be the same as that discussed for Alternative A, above.
No significant impacts on air quality will result.

### Alternative C---All new sites using USCG-like equipment

The level of short-term, local air quality impact associated with the
construction of a typical NDGPS reference station using current USCG
equipment at new sites will be less than that discussed for Alternative
A, above. Individual site size will be less than 11 acres; hence, land
disturbance associated with a smaller copper ground plane will create
proportionately less dust (depending on local site conditions and
climate). Operation and maintenance practices will be the same as
Alternative A; hence, long-term air quality impacts under this
alternative will also be insignificant. Emission of criteria pollutants
at any proposed reference station site will be negligible. No
significant impacts on air quality will result.

### Alternative D---No-action alternative

The no-action alternative would not result in the air quality impacts
expected to result from implementation of the proposed NDGPS.
Decommissioned GWEN facilities would be dismantled and removed creating
minor, short-term emissions of dust, HC, and NO~x~. The absence of NDGPS
capabilities would have no foreseeable direct or indirect effects on air
quality. GWEN site leases with private landowners or land-use agreements
with other federal land managers would be terminated. No significant
impacts on air quality will result.

## noise

### Alternative A (Preferred Action)---Mix of GWEN sites and equipment plus new sites and equipment

Short-term noise impacts associated with site clearing and preparation
and the installation of facilities would occur. Noise would also be
associated with dismantling the facility upon decommissioning of the
reference stations. Except for the use of specific equipment during
brief segments of the construction (and dismantling) periods, average
project-related noise is expected to be well below recommended levels
for human exposure. Average noise levels 50 ft from the source can reach
84 dB for ground clearing activities, 78 dB for foundations, and 85 dB
for steel erection. Considering noise attenuation by both distance and
terrain, noise generated during NDGPS installation and dismantling would
be considered a short-term, daytime nuisance rather than a health
concern. Potentially significant impacts because of noise generated
during the construction period would be prevented by limiting
construction to normal working hours and shutting off equipment when not
in use. Noise impacts due to the conversion of GWEN facilities to NDGPS
reference stations will not be significant.

No noise sources are present during NDGPS operation, except for the rare
use of the BUPG during power failure. Noise levels generated by the BUPG
will be below significant levels provided that a manufacturer's silencer
is installed and operating. The government plans to include this feature
as a standard practice. No significant long-term change to the average
ambient noise level will occur because of the proposed project.
Likewise, no significant cumulative impacts will occur regardless of
other adjacent noise sources. During operation of the NDGPS facility,
even the most sensitive noise receptors would not be significantly
affected. No significant noise impacts will result from facility
operation and maintenance.

### Alternative B---Mix of GWEN sites and new sites using new equipment

The levels of unavoidable, short-term noise associated with the
construction of a new NDGPS reference station would be roughly
equivalent to that discussed for Alternative A, above. Use of
construction equipment would be similar as for Alternative A. Any
potentially significant impacts because of noise generated during the
construction period would be prevented by limiting construction to
normal working hours and shutting off equipment when not in use. The
government plans to include this action as a standard practice. No
significant cumulative noise effects will occur. Project-related noise
sources will generally be absent during the operation of NDGPS reference
stations. Installing a silencer on the BUPG will ensure noise emissions
are below levels of significance. No significant noise impacts will
result from facility operation and maintenance.

### Alternative C---All new sites using USCG-like equipment

The level of short-term, local noise generated during the construction
of a typical NDGPS reference station using current USCG equipment at new
sites will be roughly the same as that discussed for Alternative A,
above. Land-clearing activity associated with a smaller site area will
generate similar noise levels, but for a slightly shorter construction
period. No significant noise impacts will result from facility operation
and maintenance.

### Alternative D---No-action alternative

Ambient noise levels at new reference station sites would remain
unchanged. Decommissioned GWEN facilities would be dismantled and
removed creating noise levels similar to those discussed for Alternative
A. This impact would be minor and short term. The absence of NDGPS
service would have no foreseeable direct or indirect effect on ambient
noise. GWEN site leases with private landowners or land-use agreements
with other federal land managers would be terminated. No significant
noise impacts will result.

## Visual Resources

### Alternative A (Preferred Action)---Mix of GWEN sites and equipment plus new sites and equipment

The principal visual element of the proposed NDGPS reference station
will be the 299 ft-tall steel-lattice antenna tower and associated guy
wires and top-loading elements. The proposed shelters at the base of the
tower, the two shelters near the perimeter of the property, and the twin
30 ft antenna masts will not be visually dominant from the most direct
viewpoints more than 500 ft from the site boundary. For the conversion
of GWEN facilities to NDGPS reference stations, no change in the
existing visual quality of the affected area would result. The proposed
twin antenna masts would essentially replace the existing UHF (ultra
high frequency) antenna located on a number of existing GWEN sites. The
number (three), size, and location of electronic equipment and BUPG
shelters will essentially be the same as that of the existing GWEN site.

The 299 ft tower and land clearing will be the primary elements
affecting visual quality at new sites. The method used to assess the
visual impact of similar GWEN tower facilities may be applied to
determine the visual impact of proposed NDGPS facilities at new sites.
This method uses the BLM VRM classifications described in Section 5.6.2.
As with GWEN, the visual analysis for newly proposed NDGPS reference
station sites will consider the following factors: the distance from
which an element is viewed, focal-point sensitivity, skyline complexity,
competing feature interest, and physical screening.

Distance affects the degree of contrast an object will have within the
surrounding landscape. An object loses much of its identity with greater
distance. For GWEN relay nodes, views from less than 0.5 mi (foreground)
and greater than about 1.5 mi (distant) are most strongly affected by
this factor alone (USAF, 1987). Foreground views of the transmit tower
tend to dominate at these distances; however, the 60 ft- or 150 ft-tall
GWEN UHF tower contributes strongly to the assignment of Class IV
(dominant) within 0.5 mi. For NDGPS, the twin 30 ft-tall masts would not
be as conspicuous at this distance; hence, a Class III (codominant)
assignment would be appropriate for NDGPS locations with a competing
interest or a complex skyline. When viewed from 0.5 mi to 3 mi away, the
GWEN LF tower could be discerned and in rare circumstances would compete
for, or be the object of attention (USAF, 1987). The screening effect of
vegetation and terrain proved effective in making the structure appear
relatively distant, subordinate, and less obtrusive. For many
conditions, the tower would fall into Class I: it could not be noticed
unless specifically pointed out. When viewed from beyond 3 mi, the tower
could not be discerned. Clearing of vegetation or surface soil would
create a marked contrast to the surrounding environment. For a clearing
of approximately 11 acres performed on nearly level terrain, this would
usually not be a concern beyond 0.75 mi.

For distances within 3 mi, relative amounts of skyline complexity,
focal-point sensitivity, and competing features would affect whether a
Visual Modification Class (VMC) rating of II, III or IV is assigned
(USAF, 1987). Focal-sensitivity considers focal points directing viewer
attention, particularly in areas that receive public attention. These
focal points occur with abrupt changes in a sequence or pattern of
landscape or when a sudden shift in viewing direction is encountered.
Skyline complexity is the relative degree of irregularity created at the
horizon by masses of vegetation, topography, or structures. Irregularity
can be created by the vertical difference between the highest and lowest
point along the skyline. Irregular skylines are more complex and tend to
mask the appearance of an added element, such as a GWEN or NDGPS
transmit tower. Competing interest is when a feature of strong visual
interest is included within the view of the tower. Such features are
commonly farm buildings, dominant mountain crests, and lakes. These
features of added interest tend to draw attention away from other
elements, such as a GWEN or NDGPS tower structure. Focal-point
sensitivity and skyline complexity are generally given relative
assignments of low, moderate, and high, while competing interest is
either present or absent. Table 7 indicates the appropriate assignment
of a VMC rating used for GWEN relay node facilities based on varying
conditions.

In summary, the primary visual elements would be the 299 ft-tall NDGPS
transmit tower and the contrast created by the clearing of the ground
surface. The visual modification from these features would tend to be
dominant (Class IV) when viewed from less than 0.5 mi, except when a
competing feature and moderate-to-high skyline complexity is present to
provide a codominant visual feature (Class III). A high skyline
complexity with no focal-point sensitivity could render the visual
modification as simply noticeable (Class II). Between 0.5 mi and 1.5 mi,
the tower would appear visually dominant (Class IV) only if the skyline
complexity were low and there were no other competing features of
interest. Beyond 1.5 mi, the tower would be barely noticeable or, at
worst, very subordinate.

+----------------+-----+------+-----+-----+-------+-----+-----------+
| Table 7\       |     |      |     |     |       |     |           |
| VMC Ratings    |     |      |     |     |       |     |           |
| for Various    |     |      |     |     |       |     |           |
| Conditions     |     |      |     |     |       |     |           |
+----------------+-----+------+-----+-----+-------+-----+-----------+
| **[factors]    | **[ |      |     |     |       |     |           |
| {.smallcaps}** | VMC |      |     |     |       |     |           |
|                | rat |      |     |     |       |     |           |
|                | ing |      |     |     |       |     |           |
|                | ]{. |      |     |     |       |     |           |
|                | sma |      |     |     |       |     |           |
|                | llc |      |     |     |       |     |           |
|                | aps |      |     |     |       |     |           |
|                | }** |      |     |     |       |     |           |
+----------------+-----+------+-----+-----+-------+-----+-----------+
| Focal Point    | L   |      |     | 0.5 |       |     | **1.5 to  |
| Sensitivity/\  | ess |      |     | to  |       |     | 3.0       |
| Competing      | t   |      |     | 1.5 |       |     | mi\***    |
| Feature\       | han |      |     | m   |       |     |           |
| Interest       | 0.5 |      |     | i\* |       |     | Relative  |
|                | m   |      |     |     |       |     | Skyline   |
|                | i\* |      |     | Re  |       |     | C         |
|                |     |      |     | lat |       |     | omplexity |
|                | Re  |      |     | ive |       |     |           |
|                | lat |      |     | Sk  |       |     |           |
|                | ive |      |     | yli |       |     |           |
|                | Sk  |      |     | ne\ |       |     |           |
|                | yli |      |     | C   |       |     |           |
|                | ne\ |      |     | omp |       |     |           |
|                | C   |      |     | lex |       |     |           |
|                | omp |      |     | ity |       |     |           |
|                | lex |      |     |     |       |     |           |
|                | ity |      |     |     |       |     |           |
+----------------+-----+------+-----+-----+-------+-----+-----------+
|                | **  | **Mo | *   | **  | Mod   | *   | **Not a   |
|                | Hig | dera | *Lo | Hig | erate | *Lo | Factor**  |
|                | h** | te** | w** | h** |       | w** |           |
+----------------+-----+------+-----+-----+-------+-----+-----------+
| [N             | IV  | IV   | IV  | II  | II or | III | I or II   |
| o]{.underline} |     |      |     | or  | III   | or  |           |
| focal point    |     |      |     | III |       | IV  |           |
| sensitivity\   |     |      |     |     |       |     |           |
| [N             |     |      |     |     |       |     |           |
| o]{.underline} |     |      |     |     |       |     |           |
| competing      |     |      |     |     |       |     |           |
| feature        |     |      |     |     |       |     |           |
| interest       |     |      |     |     |       |     |           |
+----------------+-----+------+-----+-----+-------+-----+-----------+
| Focal point    | IV  | IV   | IV  | III | III   | IV  | I or II   |
| sensitivity\   |     |      |     | or  | or IV |     |           |
| [N             |     |      |     | IV  |       |     |           |
| o]{.underline} |     |      |     |     |       |     |           |
| competing      |     |      |     |     |       |     |           |
| feature        |     |      |     |     |       |     |           |
| interest       |     |      |     |     |       |     |           |
+----------------+-----+------+-----+-----+-------+-----+-----------+
| Focal point    | III | III  | III | II  | III   | III | I or II   |
| sensitivity\   |     | or   | or  | or  |       |     |           |
| Competing      |     | IV   | IV  | III |       |     |           |
| feature        |     |      |     |     |       |     |           |
| interest       |     |      |     |     |       |     |           |
+----------------+-----+------+-----+-----+-------+-----+-----------+
| [N             | II  | III  | III | II  | II or | II  | I or II   |
| o]{.underline} | or  |      | or  |     | III   | or  |           |
| focal point    | III |      | IV  |     |       | III |           |
| sensitivity\   |     |      |     |     |       |     |           |
| Competing      |     |      |     |     |       |     |           |
| feature        |     |      |     |     |       |     |           |
| interest       |     |      |     |     |       |     |           |
+----------------+-----+------+-----+-----+-------+-----+-----------+
| \*Distance is  |     |      |     |     |       |     |           |
| that between   |     |      |     |     |       |     |           |
| observer       |     |      |     |     |       |     |           |
| position and   |     |      |     |     |       |     |           |
| NDGPS          |     |      |     |     |       |     |           |
| facilities.    |     |      |     |     |       |     |           |
+----------------+-----+------+-----+-----+-------+-----+-----------+

Potentially significant long-term visual impacts would occur if a
medium- to high-sensitivity view were affected by a Class IV VMC, and if
a high-sensitivity view were affected by a Class III VRM.
Medium-sensitivity views affected by a Class III VRM would result in a
moderate (less than significant) visual impact. To eliminate this
potential for significant visual impact during site selection, proposed
NDGPS reference stations will be located at least 1.5 mi from areas
designated for their visual sensitivity (e.g., scenic roads, rivers,
national parks and monuments, scenic vistas within national and state
forests, and open space districts) whenever feasible. With this siting,
no significant impacts would result.

### Alternative B---Mix of GWEN sites and new sites using new equipment

The analysis for Alternative A applies to Alternative B. No significant
impacts would result.

### Alternative C---All new sites using USCG-like equipment

Assuming 120 ft towers are to be used, visual resource impacts would
likely be less than significant for all sites except those within 0.5 mi
of the most sensitive areas. Proposed NDGPS reference stations with
towers 120 ft tall or less will be located 0.5 mi or more from a
sensitive visual resource area, as identified in Section 6.6.1.
Screening of fences and shelters using vegetation would reduce visual
impacts. No significant impacts would result.

### Alternative D---No-action alternative

The no-action alternative would not result in visual impacts. The
existing visual environment at non-GWEN site locations would remain
unchanged. The decommissioned GWEN facilities would not be reused, and
the USAF would dismantle and remove those facilities including the
299 ft tower. This would result in a marginal enhancement of the
existing visual conditions at and near those sites. The absence of NDGPS
service would have no foreseeable direct or indirect effect on visual
quality. GWEN site leases with private landowners or land-use agreements
with other federal land managers would be terminated. Benefits of more
accurate NDGPS service to users would not be realized under this
alternative. No significant impacts would result.

## flora and fauna

### Alternative A (Preferred Action)---Mix of GWEN sites and equipment plus new sites and equipment

The proposed conversion of GWEN sites to NDGPS reference stations is
unlikely to result in a significant impact to flora and fauna, including
federal- and state-listed threatened and endangered species. The
potential does exist for protected species to occur at a GWEN site
converted to DGPS use; however, based on the environmental siting
criteria established in the GWEN Final EIS and applied during individual
site selection for GWEN relay nodes, it is unlikely that listed species
occur at GWEN properties. No significant impacts to protected species
would result from the installation and operation of NDGPS at former GWEN
properties. To ensure that protected species will not be significantly
affected by the conversion of GWEN sites to NDGPS reference stations,
the FHWA will obtain current listings of federal and state-protected
species per Section 7 of the Endangered Species Act. Based on
information regarding these protected species, the FWHA will determine
whether the potential to effect any of these species exists because of
the proposed project and will consult with regulatory agencies regarding
its determination. The USFWS field office will be contacted regarding
federally listed species, and, for state-listed species, the responsible
state agency (e.g., departments of fish and game) will be contacted.

If the FHWA determines that no effect upon protected species will result
and the regulatory agency concurs, no further action is necessary. If a
"may effect" determination is made for protected species, formal
consultation and, if necessary, a biological assessment will be
performed to determine the level of impact to protected flora or fauna.
Should the potential for significant impact exist, the FHWA plans to
apply appropriate mitigation measures to reduce this potential impact to
insignificant levels. The specific mitigation measures to be taken will
be determined during consultation with appropriate regulatory agencies
prior to site acquisition. Mitigation measures planned by the FHWA
include not undertaking all or portions of the proposed action at the
affected GWEN location or compensating for any critical loss of species
or their habitat by resource conservation, management or replacement
methods agreed upon with the appropriate regulatory agency.

For NDGPS reference stations proposed on new (non-GWEN) properties,
project related ground disturbance may occur anywhere within the
approximately 11-acre property boundary. For previously undeveloped
properties, ground clearing to install the proposed towers, copper
ground plane, shelters, and access drive would displace habitat for
common plant and animal species. Unless protected species are
jeopardized, this amount of common habitat displacement would not result
in a significant biological impact.

During the evaluation and selection of candidate sites for new NDGPS
reference stations, the government will comply with the Endangered
Species Act and other regulatory requirements previously cited in
Section 5.7. During the evaluation of candidate sites, the FHWA plans to
consult with appropriate regulatory agencies, as discussed above, to
determine whether protected species may be adversely affected. In cases
where protected species may be adversely affected, additional
consultation will be performed and, if necessary, a biological
assessment will be prepared to determine the level of potential impact.
Should the potential for significant impact exist, the FHWA plans to
apply appropriate mitigation measures to reduce this potential to less
than significant levels. The specific mitigation measures to be taken
will be determined during consultation with appropriate regulatory
agencies prior to site acquisition. Mitigation measures planned by the
FHWA include not undertaking all or portions of the proposed action at
the selected site location or compensating for any critical loss of
species or their habitat by resource conservation, management, or
replacement methods agreed upon with the appropriate regulatory agency.

In general, habitat areas likely to support protected species will be
avoided, such as wetlands, riparian habitat, diverse native plant
communities, and areas with large, contiguous native old-growth forest
habitat. In addition to on-site project activities, the potential
effects from off-site activities, such as the additional infrastructure,
should be considered. For example, where appropriate, new overhead power
lines should be designed to prevent the electrocution of raptors, and
traffic through some remote areas may jeopardize protected species that
use existing/proposed access routes. Given that avoidance of protected
species and their habitats can be achieved or that consultation with
federal and state regulatory agencies will result in a no adverse effect
determination, no significant impacts to flora or fauna will occur. If
for unforeseeable reasons the FHWA and federal or state regulatory
agencies find that a potentially significant adverse impact will occur,
additional analysis will be performed to determine what mitigation
measures are necessary to reduce the impact to less than significant
levels.

The proposed 299 ft-tall tower may represent a hazard to birds in
flight. Collisions with the tower or its guy wires and top-loading
elements may result in bird mortality. As discussed in the GWEN Final
EIS and in other literature, the most common episodes of avian mortality
involve migrating songbirds, or passerines, that have become disoriented
during stormy or overcast conditions (USAF, 1987). While birds have been
killed from strikes on shorter, 100 ft‑tall towers, the majority of bird
mortality incidences are associated with towers over 300 ft in height.
Indeed, the greatest risk to birds in flight involves towers over 500 ft
tall, which are typical for radio and television broadcast antennas.
Raptors and waterfowl appear to be less susceptible to collisions with
towers or guy wires. Raptors are agile species with keen eyesight and
are adept at avoiding tall structures; however, nest sites within 1.5 mi
can be disturbed by construction-related noise and activity. By
consulting with local and regional USFWS offices, known nest sites and
other critical habitat could be avoided during nesting and rearing
seasons. Low flights by migratory birds such as waterfowl are more
common between wetland areas and adjacent or nearby open feeding areas.
For proposed NDGPS tower facilities planned in or near major migratory
corridors such as the Pacific, Atlantic, and Central flyways,
prospective sites between adjacent, local stopover locations (broad
wetlands habitat) and feeding areas (typically open fields) will be
avoided. By locating NDGPS reference stations more than 3 mi from
critical avian habitat within major flyways, the potential for avian
mortality to migratory birds is reduced to an insignificant impact. In
addition, consultation with the USFWS will be performed to confirm that
the location of the proposed facilities is consistent with policies of
the Migratory Bird Treaty Act.

The proposed action is expected to result in approximately the same
level of copper leaching into the soil as anticipated for the existing
GWEN facilities. As discussed in the GWEN Final EIS (p. 4.4--7), the
addition of copper is "unlikely to have any detrimental effect on
resident land plants" as long as "soil pH were above 6.5 and cation
exchange capacity were above 15 milli-equivalent per 100 grams
(m~eq~/100 g)." If these conditions cannot be met, significant impacts
would only occur to plant species of "special concern." Animal species
consuming such plants are not expected to be affected in any case (USAF,
1987).

The potential for significant impact upon aquatic biota depends on the
water hardness of a given resource. The GWEN Final EIS states that
concentrations in excess of 10 µg/l may generate a variety of adverse
effects. For the GWEN ground plane located 1 ft beneath the ground
surface, aquatic habitat within 300 ft would not be exposed to adverse
levels of project-related copper unless the soil pH is below 6.5, the
seasonally high water table was within 1.3 m of the surface, and the
subsurface flow is directed toward the aquatic resource. If these
conditions cannot be avoided, surface water concentrations for copper
could exceed acceptable standards and a very localized but long-term
adverse impact would arise. Depending on concern registered by USFWS,
state agencies, and scientific organizations, this impact could be
significant (USAF, 1987). In the unlikely circumstance in which areas
with acidic soils, a high water table, and nearby aquatic resources
cannot be avoided, an effective mitigation measure is to add lime to the
soil to raise its pH above 6.5. This action would eliminate the
potential for significant impacts to aquatic flora and fauna caused by
the amount of copper released into the environment.

Upon decommissioning, the government plans to evaluate and restore NDGPS
sites so that environmental impacts because of copper leached into the
soil and any hazardous materials in the environment are removed or
reduced to insignificant levels. These actions will eliminate the
potential for significant long-term impacts to subsequent users of the
property.

Cumulative effects may occur because of NDGPS reference station
facilities located at either new sites or existing GWEN properties. New
sites near existing tower structures located within a major avian flyway
could result in a significant cumulative impact; however, these areas
would be avoided during the siting process. Because of the widely spaced
siting requirements of adjacent NDGPS reference stations, no significant
cumulative or individual impacts to flora and fauna will result.

### Alternative B---Mix of GWEN sites and new sites using new equipment

This alternative would have similar impacts as described for Alternative
A, above. No significant impacts will result.

### Alternative C---All new sites using USCG-like equipment

This alternative would be less likely to result in bird strikes at any
one reference station because of the use of shorter towers. However, a
greater number of towers is required and may result in siting near
wetlands and other waterfowl habitat. The same magnitude of impact is
expected for this alternative as that described for Alternative A.
Environmental siting criteria previously discussed will be applied,
including agency consultation and mitigation, performed in accordance
with the Endangered Species Act and the Migratory Bird Treaty Act. No
significant impacts will result.

### Alternative D---No-action alternative

The no-action alternative would eliminate any resource impacts
anticipated from the implementation of the proposed NDGPS service.
Habitat values and existing flora and fauna at new (non-GWEN) NDGPS
reference station locations would remain unchanged. Decommissioned GWEN
facilities would be dismantled and removed, potentially adding habitat
value to some former GWEN locations. GWEN site leases with private
landowners or land-use agreements with other federal land managers would
be terminated. The absence of NDGPS service would not have a foreseeable
direct or indirect impact on flora and fauna resources. No significant
impacts will result.

## cultural resources

### Alternative A (Preferred Action)---Mix of GWEN sites and equipment plus new sites and equipment

Under Alternative A, 32 GWEN relay nodes would be converted to NDGPS
reference stations. During implementation of the GWEN project and the
associated NEPA compliance process, those sites underwent Section 106
review with SHPOs and, in some cases, additional review with the ACHP.
Because new ground-disturbing activities would be confined to the
existing project area that has received SHPO and ACHP clearance, no
impacts to cultural resources would occur at those sites. To comply with
Section 106, however, the FHWA would submit project information for
review to the SHPO as required by 36 CFR Part 800.4.

Implementation of Alternative A would result in the identification and
land acquisition of 35 new sites. Potentially significant long-term
impacts include the following:

-   Partial or full physical destruction of archaeological or
    architectural resources, traditional cultural properties, or other
    Native American resources during site preparation and
    ground-disturbing activities

-   Visual impacts from the 299 ft tower or utility lines on historic
    structures or their settings, historic districts, historic or
    cultural landscapes, and traditional cultural properties

-   Restricted access to traditional-use areas by members of an ethnic
    minority group

-   Increased public access to traditional cultural sites by the general
    public because of installation of new roadways.

Potentially significant short-term impacts include noise impacts on
nearby traditional cultural properties caused by construction
activities.

Cumulative impacts on cultural resources could occur from installation
of an NDGPS reference station within a particular area when added to
other projects being undertaken in the vicinity. Cumulative impacts of
this nature will be determined by obtaining current and future
development plans from local planning agencies and during consultation
with the SHPO.

The most effective means of avoiding significant impacts to cultural
resources would be through the site-selection process. Environmental
siting criteria that will be used by the government to avoid significant
impacts to cultural resources include the following:

-   Avoid known cultural resources listed or eligible for listing on the
    NRHP

-   Avoid siting within 1.5 mi of a known significant cultural resource
    with high visual sensitivity (see Section 5.6)

-   Avoid traditional cultural properties and other resources and use
    areas that are known to have significance for Native Americans

-   Avoid siting at or near historic resources of state or local
    importance that are not listed or eligible for listing on the NRHP.

Although adherence to the environmental siting criteria would avoid
significant adverse effects to cultural resources in most instances, it
may be necessary to proceed with site-specific analysis under specific
unusual conditions. In some cases, it may be necessary to conduct an
archaeological or historic structure survey or consult with appropriate
Native American traditional cultural leaders or other ethnic minority
groups before sufficient information is known about the location and
types of resources that may be present in the area of potential effect.
It may also not be possible to avoid affecting particular cultural
resources such as historic structures or archaeological sites during the
site-selection process because of technical, operational, or cost
considerations. Should this occur, the following measures would be taken
to ensure that a mitigation strategy would be followed. These measures
would be carried out in consultation with the SHPO and would follow
procedures established under 36 CFR Part 800 to comply with Section 106
of the NHPA and any state standards that may apply to cultural resources
investigations.

-   In consultation with the SHPO, identify and evaluate cultural
    resources that are present in the area of potential effect and
    determine project effects.

-   Develop procedures in consultation with the SHPO to avoid or
    mitigate adverse effects through data recovery (for both
    archaeological and historic architectural resources) in accordance
    with federal, state, and local regulations.

-   Develop a strategy to ensure that previously unidentified
    archaeological resources encountered during site preparation and
    construction are protected and afforded appropriate management
    treatment.

-   If human remains or items of cultural patrimony are encountered,
    consult with the appropriate state or federal agencies or Native
    American group. Exhumation, study, and disposition of any human
    remains would comply with all federal, state, and local laws.

-   Properly analyze, report on, and curate all recovered archaeological
    resources.

-   Request the comments of the ACHP.

Based on the site selection and mitigation strategies outlined above, no
significant impacts will result.

### Alternative B---Mix of GWEN sites and new sites using new equipment

Implementation of Alternative B would result in the same level of
potential impacts to cultural resources as those described above under
Alternative A, and the same environmental siting criteria and all
mitigation measures apply to Alternative B. No significant impacts will
result.

### Alternative C---All new sites using USCG-like equipment

Under Alternative C, a greater number of NDGPS reference stations will
be required nationwide, and the potential for encountering cultural
resources would increase. The ability to avoid known significant
cultural resources may be slightly more difficult to accomplish, but
adherence to the environmental siting criteria is achievable with
similar limitations as described under Alternative A. The potential for
encountering archaeological resources at prospective sites or during
construction of the NDGPS facilities would also increase slightly under
this alternative; however, the environmental siting criteria and
mitigation strategy described above would apply. No significant impacts
will result.

### Alternative D---No-action alternative

The no-action alternative would eliminate direct resource impacts
anticipated from the implementation of the proposed NDGPS. Cultural
resources existing at new (non-GWEN) NDGPS reference station locations
would remain unaffected. Decommissioned GWEN facilities would be
dismantled and removed. Based on the environmental site-selection
criteria contained in the GWEN Final EIS and applied during site
selection, cultural resources are not present at existing GWEN
properties. No cultural resources would be affected at decommissioned
GWEN relay node sites during removal of GWEN facilities and no
additional ground disturbance would occur outside of the GWEN relay
node; thus, no archaeological resources would be affected by removal of
the facilities. GWEN site leases with private landowners or land-use
agreements with other federal land managers would be terminated. In the
absence of NDGPS service, no direct impacts to cultural resources would
occur. Indirect benefits of NDGPS related to new methods to locate and
reestablish cultural resources survey locations would not be achieved.
No significant impacts will result.

### Statement of Compliance with Section 4(f) of the DOT Act

Section 4(f) of the DOT Act (40 U.S. Code 303) requires analysis of
possible impacts arising from FHWA actions on historic properties and
stipulates that DOT projects may not be sited on land from a historic
site of national, state, or local significance as determined by the
officials having jurisdiction thereof, unless no other prudent and
feasible alternative is possible and all possible planning is taken to
minimize harm to the historic site to be used.

As described above, no significant unavoidable impacts would result from
conversion of existing GWEN sites to NDGPS reference stations,
construction and operation of NDGPS reference stations at newly acquired
site locations, or decommissioning of NDGPS as long as the proposed
environmental siting criteria are adhered to or appropriate mitigation
is applied. Implementation of the proposed action would not result in
significant impacts on cultural resources and would be consistent with
policies in Section 4(f) of the DOT Act.

## recreation

### Alternative A (Preferred Action)---Mix of GWEN sites and equipment plus new sites and equipment

Potentially significant long-term impacts on recreational resources
could occur if proposed NDGPS reference stations are located within
areas designated as wilderness areas, national and state parks, national
and state recreation areas, national seashores, and other designated
recreational areas listed in Section 5.9.1. Those areas are normally
regulated by general management plans that identify management zones and
prohibit incompatible uses. Potentially significant long-term visual
effects could also result from siting an NDGPS facility too close to
designated scenic vistas within national and state forests. Potential
adverse effects could occur to locally designated or undesignated
recreational areas where recreational activities would be impeded or
diminished as a result of installation of an NDGPS facility. Although
the probability is low, the potential also exists for impacts to result
from increased access to resources from the construction of new
roadways. However, should this occur, it would result in a beneficial
effect since the recreational resource would be more accessible to the
public. Potential short-term effects on recreational resources could
result from temporary increases in traffic and noise during the
construction period.

Under Alternative A, potential impacts on recreational resources could
occur from installation of NDGPS facilities at newly acquired sites.
Existing GWEN relay nodes that would be converted to NDGPS reference
stations would not result in impacts on recreational resources. The most
effective means of avoiding impacts to recreational resources is through
the site-selection process. Environmental siting criteria that will be
used to avoid significant impacts include the following:

-   Avoid wilderness areas and wilderness study areas designated in
    accordance with the Wilderness Act

-   Avoid national and state parks, national and state recreation areas,
    national sea shores, national monuments, national historic sites,
    state beaches, and state fishing areas designated by the Department
    of Interior or state agencies with jurisdiction over recreational
    areas

-   Avoid national natural landmarks in accordance with the National
    Natural Landmarks Program

-   Avoid locally designated or undesignated local recreational areas
    where recreational activities would be impeded or lost, such as
    county and municipal parks, reservoirs, county beaches, and other
    recreational areas used by the populace.

Adherence to these environmental siting criteria would ensure that
significant impacts on recreational land use would not result.
Potentially significant impacts on visually sensitive recreational areas
could be avoided by siting the NDGPS facilities at least 1.5 mi away
from the resource. This site-selection criteria is based on the visual
analysis that was conducted for resources with medium- to
high-sensitivity views (see Sections 5.6 and 6.6, Visual Resources).
Project related traffic volumes on existing roadways during construction
would be low and temporary. Long-term traffic would be infrequent,
approximately one or two vehicles per month. This effect on recreation
would be insignificant.

Adhering to the environmental siting criteria will also minimize
potential short-term impacts during the construction period. For
proposed NDGPS reference stations sited at least 1.5 mi from national,
state, or local recreational resources, increases in traffic because of
construction-related activities or noise generated during construction
would have little or no effect on resources. No significant impacts on
recreational resources would result.

### Alternative B---Mix of GWEN sites and new sites using new equipment

The potential for recreational impacts associated with the construction
and operation of NDGPS reference stations using USCG-like equipment
would be comparable to those discussed for Alternative A, above, and the
same environmental siting criteria would apply. No significant impacts
on recreational resources would result.

### Alternative C---All new sites using USCG-like equipment

Environmental siting criteria would apply to all new reference stations
using USCG-like equipment proposed under Alternative C. Because no
significant unavoidable impacts would result if the environmental siting
criteria are adhered to, project effects under Alternative C would be
the same as those discussed under Alternative A.

### Alternative D---No-action alternative

The no-action alternative would eliminate direct resource impacts
anticipated from the implementation of the proposed NDGPS service.
Recreational resources at new (non-GWEN) NDGPS reference station
locations would remain unaffected. Decommissioned GWEN facilities would
be dismantled and removed, and GWEN site leases with private landowners
or land-use agreements with other federal land managers would be
terminated. No significant impacts on recreational resources would
result.

### Statement of Compliance with Section 4(f) of the DOT Act

Section 4(f) of the U.S. DOT Act of 1966 states that a DOT action
requiring the use of any publicly owned land from a public park,
recreation area, or wildlife and waterfowl refuge of national, state, or
local significance or land from a historic site of national, state, or
local significance will be approved only if there is no feasible and
prudent alternative to the use of such land, and the action includes all
possible planning to minimize harm resulting from the use.

Based on application of the environmental siting criteria, no NDGPS
reference station site will be located within a designated recreational
area of national, state, or local significance. No significant
unavoidable impact would result from construction, operation, and
decommissioning of NDGPS in conformance with the proposed environmental
siting criteria.

Section 4(f) also applies to indirect use of recreation or conservation
properties under the constructive use principle. Under this principle,
Section 4(f) applies where the facts support the proposition that the
proposed action would constitute "constructive use" of adjacent Section
4(f) property. For example, as defined in 23 CFR 771.135(p)(2) of the
FHWA Regulations, constructive use:

> occurs when the transportation project does not incorporate land from
> a Section 4(f) source, but the project\'s proximity impacts are so
> severe that the protected activities, features, or attributes that
> qualify a resource for protection under Section 4(f) are substantially
> impaired. Substantial impairment occurs only when the protected
> activities, features, or attributes of the resource are substantially
> diminished.

The regulations at 23 CFR 771.135 describe certain situations where
constructive use would be found such as:

-   Where there is excessive noise when the project is adjacent to a
    noise-sensitive facility

-   Where the aesthetic features of the protected facility would be
    impaired or obstructed

-   Where the proposed project would result in the restriction of access
    to the protected facility

-   Where the vibration impact of the project would substantially impact
    the use of the protected facility

-   Where the ecological intrusion of the project would substantially
    diminish the value of protected wildlife habitats adjacent to the
    project (23 CFR 771.135(4)).

Installation, operation, and decommissioning of NDGPS would not remove
land from existing recreation or conservation use and would not cause
constructive use of designated recreation or conservation properties.
Therefore, no direct or constructive impacts on Section 4(f) properties
would result.

## land use

### Alternative A (Preferred Action)---Mix of GWEN sites and equipment plus new sites and equipment

Under the Public Buildings Amendments of 1988, the federal government is
not bound by local planning and zoning land-use requirements, but is
directed to consider them in the project planning and decision-making
process and accommodate state and local concerns to the extent
practicable. Some rural areas are not officially zoned for a specific
use and may or may not have specific restrictions or review processes
for tower structures. Many areas with land-use guidelines and zoning
regulations allow tower facilities outright and provide for a variance
to stated zoning requirements or offer a conditional use permit to
nonfederal applicants. In the latter case, height restrictions as well
as public health and visual aesthetic concerns may need to be addressed
with the local jurisdiction. With the proliferation nationwide of 30 to
100 ft-tall transceiver antenna towers for cellular and digital personal
communication devices, many local jurisdictions have specified or plan
to specify conditions on the location and design of some tower
structures.

Land use concerns at the local level may also include the potential for
effects upon regional landmarks, historic properties, heritage
districts, and scenic viewsheds. Under the Public Building Amendments of
1988 and E.O. 12372, local area land-use and zoning considerations
should be addressed during the NDGPS site-selection process. While
unlikely, residential land use may be affected by the proposed
construction activities. These effects (typically noise and traffic) are
expected to be short term, and insignificant. Long-term effects are not
expected to be significant; however, concern by local residents over
perceived inconsistencies with local zoning and land-use plans may
arise. Areas zoned for heavy industrial or commercial uses are likely to
be consistent with the proposed NDGPS project from a land-use
perspective. Light-industrial use tends to be located in more
aesthetically pleasing environs, often containing well-maintained
landscapes and lawns, which could be a concern in some local
jurisdictions.

Agricultural areas are typically able to absorb the conversion of 11
acres of property to nonagricultural use and are considered consistent
with the proposed use of a tower structure. Whenever feasible, prime
farmlands designated by both the state department of agriculture and the
USDA NRCS should be avoided via consultation with these agencies. If
prime, or locally important or unique, farmland cannot be avoided, a
USDA Farmland Conversion Impact Rating form will be completed and a
determination made as to whether the proposed conversion is consistent
with the FPPA. Based on the small size of individual NDGPS sites,
significant impact to prime farmland is highly unlikely; however,
significant impacts can be mitigated by altering the NDGPS site size or
design. Open or undeveloped areas may be affected if they are designated
as conservation zones or open space districts. Unrestricted open or
undeveloped areas would have no specific land-use conflicts; however,
the future use of adjacent properties may be affected because of
sensitivities concerning radiofrequency interference or aesthetic
concerns.

State and federally managed lands typically have management plans that
limit or restrict certain activities or facilities. After consultation
with the land manager, areas incompatible with an NDGPS reference
station should be avoided. If the incompatibility can be eliminated by
an acceptable change in facility layout or design, this form of
mitigation will be implemented.

For NDGPS reference station sites in states with approved state or local
coastal zone management programs, a review of applicable management
plans will be performed to determine federal consistency with the plan.
Consultation with the state Coastal Zone Management Plan (CZMP) manager
will be performed to establish a consistency determination. Conflicts
with CZMP goals and objectives will be avoided during the siting of
NDGPS reference stations.

Individual and cumulative impacts upon existing, local land-use
designations would not be significant. Submittal of NDGPS development
plans to local jurisdictions for courtesy review for up to 30 days is
required under Public Law 100-618; and city and county planning offices
should be consulted regarding the NDGPS project, its siting criteria,
and the federal government's ability to voluntarily avoid potential
conflicts with existing land-use designations, regulations, and
requirements. The federal government is not required to pay fees or make
changes recommended by the local agencies. The FHWA will avoid areas
that conflict with parks, refuge areas, recreation areas, culturally
significant properties, wilderness areas, and other resources discussed
in Sections 5.8, Recreation, and 5.9, Cultural Resources.

Land use and other natural resource benefits are expected under the
preferred action alternative. This alternative involves the maximum
reuse of GWEN equipment and properties for NDGPS. This reduces the need
for disposal of nonrenewable materials such as metals and earth
materials.

### Alternative B---Mix of GWEN sites and new sites using new equipment

This alternative would have an equivalent level of impact and the same
potential for significant impact as that described for Alternative A,
above. Land use conflicts, if any, would occur in a similar fashion, and
the methods to avoid land-use conflicts would be the same. Conflicts
with federal, state, and local land-use plans will be avoided during the
siting process, and significant impacts will not occur. Direct
environmental benefits in terms of reduction of waste and reuse of
materials arise under Alternative B from the reuse of 32 GWEN sites (but
not GWEN equipment).

### Alternative C---All new sites using USCG-like equipment

This alternative would be less likely to result in land-use conflicts at
any one site because of the use of a shorter tower and a smaller
facility size. However, because of the greater number of sites required,
some conflicts may result despite the smaller site size and lower tower
height. Conflicts with existing land-use plans will be avoided in the
site-selection process, and no significant impacts to land-use
conditions would result.

### Alternative D---No-action alternative

The no-action alternative would prevent impacts anticipated from the
implementation of the proposed NDGPS service. Existing land uses would
remain unchanged for areas where new (non-GWEN) NDGPS reference station
locations were to be considered. Decommissioned GWEN facilities would be
dismantled and removed, possibly resulting in a change in land-use
designation or zoning for that specific land parcel. This would enable
local jurisdictions to adjust land use to that which is more compatible
with adjacent parcels. GWEN site leases with private landowners or
land-use agreements with other federal land managers would be terminated
and new land uses considered by their owners. Benefits of more accurate
NDGPS services to identify remote land-use boundaries would not be
realized under this alternative. No significant impacts would result.

## socioeconomics and environmental justice

### Alternative A (Preferred Action)---Mix of GWEN sites and equipment plus new sites and equipment

#### Socioeconomics

Adherence with the environmental siting criteria described in Section
6.10, Land Use, during site selection is achievable and would avoid
land-use impacts associated with social and economic issues. Adherence
to these environmental siting criteria would also avoid local land-use
concerns and issues that could potentially arise from local residents.
No adverse impacts on land use are expected to occur. Direct economic
impacts to the residents and residential areas would not occur, as
direct impacts would be confined to the construction and staging area of
the project sites. Should a fire, break-in, or other emergency occur at
the NDGPS facilities, the services of local police and firefighter
personnel may be needed. However, no undue increase in demand on public
protective services would occur as a result of the operation and
maintenance of the proposed NDGPS facilities.

It is not likely that installation of the NDGPS facilities will affect
employment patterns on a permanent basis or induce substantial growth or
growth-related impacts. The facilities will be unmanned, and no increase
in population levels would result. Installation of the proposed
facilities at existing GWEN sites would employ 10 workers over a 30- to
45-day construction period. For construction at new sites, 15 workers
over a 2- or 3-month construction period would be needed. If the
government employs local contractors to install the facilities, this
would result in a short-term, positive impact to the local economy
although it would not necessarily be a net addition to a region's
economy. However, it is more likely that the government would bring in
its own contractors to construct the proposed facilities (Pugh, 1998).
If this is the case, temporary housing and other services to support the
construction workers would be required, and local hotels and motels,
restaurants, and other local businesses would benefit during the
construction period. In addition, in either scenario, construction
materials needed for installation of the facilities and available
locally would be purchased from local suppliers.

In economies that rely heavily on tourism and recreation, significant
short-term impacts could potentially occur on temporary housing. If the
construction period occurs during the peak travel season in a given
region when lodging is at or near capacity, guests needing temporary
lodging could be displaced by construction workers and they may be
unable to find accommodations. Should this be the case, the government
plans to bring in temporary housing units, such as trailers, to house
the workers, or the construction period can be shifted to avoid peak
tourist periods. If either measure is implemented, no adverse impacts on
temporary housing would result. Government personnel who would travel to
the area periodically to perform routine maintenance on the NDGPS
equipment would not adversely impact temporary housing.

Impacts of the preferred alternative on public finances would be
insignificant. The government plans to acquire about 11 acres of land
for new sites. Land acquisition would be either through a lease or
direct purchase. If up to 11 acres of land were purchased for
installation of an NDGPS facility, property tax revenues from that land
would potentially be decreased and unavailable to local governments.
Based on a study conducted by the USAF at the time the GWEN facilities
were installed, the potential effect of removing 11 acres from the tax
base would be insignificant (USAF, 1987). If the land were leased, no
tax revenue would be lost. No significant impacts would result.

#### Environmental Justice and Protection of Children

Potential impacts on ethnic minority populations, low-income
populations, and Native American groups may differ from impacts on the
general population, depending on the make-up of the particular community
and the community's distinct cultural practices. An example of this
difference is found in the phrase, "differential patterns of consumption
of natural resources." This term refers to differences in subsistence
patterns, such as the dependence by a minority or low-income population
on indigenous fish, vegetation, and wildlife as a principal part of
their diet, and to differences in the rates and patterns of consumption
as compared with rates and patterns of consumption of the general
population (CEQ, 1997).

When determining whether disproportionately high and adverse human
health effects would result on a minority or low-income population,
agencies should consider the following three factors to the extent
practicable (CEQ, 1997):

(1) Whether the health effects are significant (as employed by NEPA), or
    above generally accepted norms

(2) Whether the risk or rate of hazard exposure by a minority or
    low-income population to an environmental hazard is significant (as
    employed by NEPA) and appreciably exceeds or is likely to
    appreciably exceed the risk or rate to the general population or
    other appropriate comparison group

(3) Whether health effects occur in a minority or low-income population
    affected by cumulative or multiple adverse exposures from
    environmental hazards.

When determining disproportionately high and adverse environmental
effects on a minority or low-income population, agencies should consider
the following to the extent practicable (CEQ, 1997):

(1) Whether there is or will be an impact on the natural or physical
    environment that significantly (as employed by NEPA) and adversely
    affects a minority or low-income population; such effects may
    include ecological, cultural, human health, economic, or social
    impacts when those impacts are interrelated to impacts on the
    natural and physical environment

(2) Whether environmental effects would be significant (as employed by
    NEPA) and may have an adverse impact on minority or low-income
    populations that appreciably exceeds or is likely to appreciably
    exceed those on the general population or other appropriate
    comparison group

(3) Whether the environmental effects occur or would occur in a minority
    or low-income population affected by cumulative or multiple adverse
    exposures from environmental hazards.

Development of new site locations to support NDGPS will occur at up to
35 sites throughout CONUS and interior Alaska, therefore, it may not be
possible to avoid areas that contain significant percentages of ethnic
minority and low-income populations. However, no disproportionately high
and adverse human health and environmental impacts on ethnic minority
communities and low-income communities will result because of
installation and operation of the proposed NDGPS. No significant short-
or long-term impacts on water resources are expected to occur, as
analyzed in Section 6.2. As long as the proposed mitigation measures are
implemented at sites where soil and water table conditions are conducive
to copper mobility, no adverse impacts to surface water, vegetation, or
aquatic biota that may be consumed would occur. Individual and
cumulative impacts on air quality and from noise would be minor, and
land use and socioeconomic impacts would not be significant, as
discussed, respectively, in Sections 6.4, 6.5, 6.10 and 6.11.1.1 A
discussion of potential effects from exposure to radiofrequency
radiation (RFR) and electromagnetic fields at the NDGPS operating
frequency is presented in Section 6.13 of this PEA. The analysis
concludes that it is unlikely that anyone would be harmed by RFR outside
the 8 ft-high security fence surrounding the tower, and posted signs
warning of the danger from RF exposure would provide additional
security. It is also unlikely that anyone would suffer electric shock or
burns from exposure to the NDGPS electric fields.

Executive Order 13045 addresses safety risks to children that may result
from federal activities. This order requires each federal agency, when
taking regulatory action, to identify and assess environmental health
risks attributable to products or substances that children are likely to
come into contact with and that may disproportionately affect children.
The order also sets up a task force to coordinate federal research on
safety risks to children. Installation of NDGPS to provide greater
nationwide radionavigation and positioning capabilities is not a covered
regulatory action, and Executive Order 13045 does not specifically apply
to such an action. However, in keeping with the spirit and intent of
Executive Order 13045, this PEA examines possible health and safety
risks to those in the vicinity of NDGPS, including children, from
exposure to RF signals emitted by NDGPS and to NDGPS electric and
magnetic fields. It is unlikely that anyone, including children, would
be harmed by RFR outside the 8 ft-high security fence surrounding the
ATU, and posted signs warning of the danger from RF exposure would
provide additional security. The high security fence, which would be
locked unless maintenance personnel were present, would prevent small
children from entering the fenced area. It is also unlikely that anyone,
including children, would suffer electric shock or burns from exposure
to the NDGPS electric fields. Installation of the NDGPS would be
consistent with E.O. 13045. No significant impacts would result.

### Alternative B---Mix of GWEN site and new sites using new equipment

Potential socioeconomic and environmental justice impacts and impacts on
children under this alternative would be comparable to impacts described
under Alternative A, and the same mitigation measures would apply. No
significant impacts would result.

### Alternative C---All new sites using USCG-like equipment

Under Alternative C, a greater number of new NDGPS reference station
sites would be required nationwide, however, socioeconomic impacts would
be equivalent to those described under Alternative A, and the same
mitigation measures would apply. Although the increase in new sites from
Alternatives A and B would increase the likelihood of siting an NDGPS
within an area containing a high percentage of ethnic minority and
low-income populations, the potential for disproportionately high and
adverse human health and environmental effects would be low. The
recommendation to involve the public and minority and low-income
populations early in the NEPA process applies. The unlikely potential
for environmental health and safety risks on children from installation
of NDGPS is comparable to Alternative A. No significant impacts would
result.

### Alternative D---No-action alternative

The no-action alternative would not cause any direct, adverse resource
impacts. Existing conditions within minority and low-income areas would
remain unchanged in areas where new (non-GWEN) site locations were
considered. Decommissioned GWEN facilities would be dismantled and
removed, possibly resulting in a change in land use at locations where
minority and low-income populations currently exist. GWEN site leases
with private landowners or land-use agreements with other federal land
managers would be terminated and new land uses considered. No
significant impacts would result.

## energy

### Alternative A (Preferred Action)---Mix of GWEN sites and equipment plus new sites and equipment

Based on the number of personnel and type of equipment required, the
energy used for construction of an NDGPS reference station, both
individually and cumulatively, is not expected to exceed the capacity of
existing services or be difficult to obtain.

During operation, individual NDGPS reference stations would use
commercial 3-phase power that can offer reasonably reliable service
year-round. This level of service is expected to be available, or be
extended, to most NDGPS siting areas within the CONUS. Some areas within
the CONUS and the state of Alaska may not offer commercial service
within a distance that would enable economically feasible extension of
service lines. The use of generators, solar, or battery-powered
equipment may be considered in these rare cases. Broadcast
characteristics for each NDGPS transmitter have not been finalized;
however, a 1,000 W capacity transmitter is currently planned at each
site. The energy requirement for NDGPS reference stations would be
consistent with other similar low-power, LF broadcast antennas operating
within the U.S. Annual usage of commercial power and other energy
resources for this type of facility and its proposed level of operation
would not be significant for almost every area within the CONUS. For
remote areas such as portions of Alaska, alternative sources of primary
power may need to be considered, and the appropriate state-level permits
obtained, if necessary. No significant impact to national or local
energy consumption would result based on these power requirements.

### Alternative B---Mix of GWEN sites and new sites using new equipment

The energy requirements under Alternative B are similar to those for
Alternative A. No significant individual or cumulative impacts to energy
sources would result.

### Alternative C---All new sites using USCG-like equipment

The energy requirements under Alternative C are similar to those for
Alternative A. No significant individual or cumulative impacts to energy
sources would result.

### Alternative D---No-action alternative

The no-action alternative would result in minor impacts. Existing energy
use would remain unchanged for areas where new (non-GWEN) site locations
were to be considered. Decommissioned GWEN facilities would be
dismantled and removed, possibly resulting in a minor net reduction in
energy use for that service area. BUPG energy requirements (e.g., the
use of diesel fuel) would be eliminated. GWEN site leases with private
landowners or land-use agreements with other federal land managers would
be terminated and new land uses considered. No significant impacts would
result.

## Hazardous materials

### Alternative A (Preferred Action)---Mix of GWEN sites and equipment plus new 

###  sites and equipment {#sites-and-equipment .unnumbered}

This alternative envisions the reuse of 32 GWEN properties as NDGPS
reference stations and the relocation of certain GWEN equipment to new
sites. In addition, a number of reference stations would be installed at
newly acquired properties. Based on Environmental Baseline Survey
reports prepared by the USAF for 32 GWEN relay nodes proposed for reuse,
none of these properties contain significant amounts of hazardous
materials or environmental contamination, however, additional review and
analysis are recommended at Kirtland AFB, New Mexico, and Pueblo,
Colorado. A list of Environmental Baseline Survey reports prepared by
COMPA Industries, Inc., are listed in Table 8.

The relocation of GWEN equipment would not be expected to cause
contamination of soil or water. However, to prevent the assumption of
liability for existing contamination at new (non-GWEN) properties
acquired by the government, the FHWA should perform environmental due
diligence assessments (EDDAs) in conformance with ASTM standards prior
to acquiring those properties.

NDGPS reference stations consist principally of electronic components,
hardware and subassemblies, and generate little if any hazardous waste.
During construction and operation of the NDGPS reference stations, small
amounts of hazardous or regulated materials, such as petroleum fuels,
paints, solvents and cleaners, sealants, herbicides and pesticides, and
so on, would likely be used at the reference station properties. The use
and handling of these materials will be performed according to
applicable regulations and manufacturer's recommendations. No
contamination of the environment will result.

<table>
<colgroup>
<col style="width: 11%" />
<col style="width: 6%" />
<col style="width: 6%" />
<col style="width: 8%" />
<col style="width: 12%" />
<col style="width: 13%" />
<col style="width: 10%" />
<col style="width: 0%" />
<col style="width: 14%" />
<col style="width: 0%" />
<col style="width: 14%" />
</colgroup>
<tbody>
<tr class="odd">
<td colspan="11"><p>Table 8</p>
<p>Summary of GWEN Environmental Baseline Surveys</p></td>
</tr>
<tr class="even">
<td>GWEN Site</td>
<td>Report Date</td>
<td>Field Survey Date</td>
<td>Ownership</td>
<td>On-Site Contamination Concerns</td>
<td>Adjacent<br />
Areas of Site Contamination or Concern Exist</td>
<td colspan="2">Category Assignment*</td>
<td>Recommendation†</td>
<td colspan="2">Comments</td>
</tr>
<tr class="odd">
<td>Appleton, WA</td>
<td>6/98</td>
<td>12/10/96</td>
<td>U.S. Govt.</td>
<td>No</td>
<td>No</td>
<td colspan="2">BUPG: 2,<br />
all else: 1</td>
<td>Proceed, with consideration of Deed Covenant &amp; Reservation of
Access</td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td>Austin, NV</td>
<td>7/98</td>
<td>11/14/96</td>
<td>U.S. Govt. (BLM)</td>
<td>No</td>
<td>No</td>
<td colspan="2">BUPG: 2,<br />
all else: 1</td>
<td>Proceed</td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td>Bakersfield, CA</td>
<td>6/98</td>
<td>12/5/96</td>
<td>Private</td>
<td>Yes</td>
<td>No</td>
<td colspan="2">BUPG: 2,<br />
all else: 1</td>
<td>Proceed</td>
<td colspan="2">Buried household waste at site.</td>
</tr>
<tr class="even">
<td>Billings, MT</td>
<td>11/97</td>
<td>10/9/96</td>
<td>Private</td>
<td>No</td>
<td>No</td>
<td colspan="2">BUPG: 2,<br />
all else: 1</td>
<td>Proceed</td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td>Bobo, MS</td>
<td>7/98</td>
<td>2/10/97</td>
<td>U.S. Govt.</td>
<td>No</td>
<td>No</td>
<td colspan="2">BUPG: 2,<br />
all else: 1</td>
<td>Proceed, with consideration of Deed Covenant &amp; Reservation of
Access</td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td>Clark, SD</td>
<td>6/98</td>
<td>10/16/96</td>
<td>Private</td>
<td>No</td>
<td>No</td>
<td colspan="2">BUPG: 2,<br />
all else: 1</td>
<td>Proceed</td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td>Edinburg, SD</td>
<td>12/97</td>
<td>10/15/96</td>
<td>Private</td>
<td>No</td>
<td>No</td>
<td colspan="2">BUPG: 2,<br />
all else: 1</td>
<td>Proceed</td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td>Fenner, CA</td>
<td>6/98</td>
<td>12/3/97</td>
<td>U.S. Govt.</td>
<td>No</td>
<td>No</td>
<td colspan="2">BUPG: 2,<br />
all else: 1</td>
<td>Proceed, with consideration of Deed Covenant &amp; Reservation of
Access</td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td>Flagstaff, AZ</td>
<td>11/97</td>
<td>10/23/96</td>
<td>U.S. Govt.</td>
<td>No</td>
<td>Yes</td>
<td colspan="2">BUPG: 2,<br />
all else: 1</td>
<td>Proceed, with consideration of Deed Covenant &amp; Reservation of
Access</td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td>Gettysburg, PA</td>
<td>6/98</td>
<td>3/6/97</td>
<td>U.S. Govt.</td>
<td>Yes</td>
<td>Yes</td>
<td colspan="2">BUPG: 2,<br />
all else: 1</td>
<td>Proceed, with consideration of Deed Covenant &amp; Reservation of
Access</td>
<td colspan="2">NPL hazardous materials site 1 mi NW, could impact
groundwater at GWEN site.</td>
</tr>
<tr class="odd">
<td>Goodland, KS</td>
<td>7/97</td>
<td>1/21/97</td>
<td>Private</td>
<td>No</td>
<td>No</td>
<td colspan="2">BUPG: 2,<br />
all else: 1</td>
<td>Proceed</td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td>Grady, AL</td>
<td>7/98</td>
<td>2/13/97</td>
<td>Private</td>
<td>No</td>
<td>No</td>
<td colspan="2">BUPG: 2,<br />
all else: 1</td>
<td>Proceed</td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td>Great Falls, MT</td>
<td>11/97</td>
<td>10/7/96</td>
<td>Private</td>
<td>No</td>
<td>No</td>
<td colspan="2">BUPG: 2,<br />
all else: 1</td>
<td>Proceed</td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td>Hackleburg, AL</td>
<td>7/98</td>
<td>2/12/97</td>
<td>Private</td>
<td>Yes</td>
<td>No</td>
<td colspan="2">BUPG: 4,<br />
all else: 1</td>
<td>Proceed</td>
<td colspan="2">A fuel leak occurred inside the BUPG shelter.</td>
</tr>
<tr class="odd">
<td>Hagerstown, MD</td>
<td>6/98</td>
<td>3/5/97</td>
<td>State of Maryland</td>
<td>Yes</td>
<td>No</td>
<td colspan="2">BUPG: 2,<br />
all else: 1</td>
<td>Proceed</td>
<td colspan="2">Buried trash in northwest part of GWEN facility.</td>
</tr>
<tr class="even">
<td>Hawk Run, PA</td>
<td>6/98</td>
<td>3/9/97</td>
<td>Private</td>
<td>No</td>
<td>No</td>
<td colspan="2">BUPG: 2,<br />
all else: 1</td>
<td>Proceed</td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td colspan="11"><p>Table 8 (concluded)</p>
<p>Summary of GWEN Environmental Baseline Surveys</p></td>
</tr>
<tr class="even">
<td>GWEN Site</td>
<td>Report Date</td>
<td>Field Survey Date</td>
<td>Ownership</td>
<td>On-Site Contamination Concerns</td>
<td>Adjacent<br />
Areas of Site Contamination or Concern Exist</td>
<td>Category Assignment*</td>
<td colspan="3">Recommendation†</td>
<td>Comments</td>
</tr>
<tr class="odd">
<td>Kirtland AFB, NM</td>
<td>6/98</td>
<td>2/13/97</td>
<td>U.S. Govt.</td>
<td>Yes</td>
<td>Yes</td>
<td>BUPG: 2, storage building &amp; undeveloped land: 7,<br />
all else: 1</td>
<td colspan="3">Proceed</td>
<td>Storage building on site may have contained hazardous materials;
past explosives testing and disposal of debris nearby may have
contaminated site.</td>
</tr>
<tr class="even">
<td>Klamath Falls, OR</td>
<td>6/98</td>
<td>11/19/96</td>
<td>Private</td>
<td>No</td>
<td>No</td>
<td>BUPG: 2,<br />
all else: 1</td>
<td colspan="3">Proceed</td>
<td></td>
</tr>
<tr class="odd">
<td>Macon, GA</td>
<td>6/98</td>
<td>2/19-20/97</td>
<td>Private</td>
<td>No</td>
<td>No</td>
<td>BUPG: 2,<br />
all else: 1</td>
<td colspan="3">Proceed</td>
<td></td>
</tr>
<tr class="even">
<td>Medford, WI</td>
<td>6/98</td>
<td>6/17/97</td>
<td>U.S. Govt.</td>
<td>No</td>
<td>No</td>
<td>BUPG: 2,<br />
all else: 1</td>
<td colspan="3">Proceed, with consideration of Deed Covenant &amp;
Reservation of Access</td>
<td></td>
</tr>
<tr class="odd">
<td>Medora, SD</td>
<td>12/97</td>
<td>10/11/96</td>
<td>U.S. Govt.</td>
<td>No</td>
<td>No</td>
<td>BUPG: 2,<br />
all else: 1</td>
<td colspan="3">Proceed, with consideration of Deed Covenant &amp;
Reservation of Access</td>
<td>Site is a portion of Little Missouri National Grassland.</td>
</tr>
<tr class="even">
<td>Onandaga, MI</td>
<td>7/98</td>
<td>4/4/97</td>
<td>Private</td>
<td>No</td>
<td>No</td>
<td>BUPG: 2,<br />
all else: 1</td>
<td colspan="3">Proceed</td>
<td></td>
</tr>
<tr class="odd">
<td>Penobscot, ME</td>
<td>11/97</td>
<td>9/24/96</td>
<td>Private</td>
<td>No</td>
<td>No</td>
<td>BUPG: 2,<br />
all else: 1</td>
<td colspan="3">Proceed</td>
<td></td>
</tr>
<tr class="even">
<td>Pueblo, CO</td>
<td>7/98</td>
<td>1/23/97</td>
<td>U.S. Army</td>
<td>No</td>
<td>Unknown</td>
<td>BUPG: 2,<br />
all else: 1</td>
<td colspan="3">Proceed</td>
<td>The entire Army depot is considered a CERCLIS site.</td>
</tr>
<tr class="odd">
<td>Ronan, MT</td>
<td>11/97</td>
<td>10/4/96</td>
<td>U.S. Govt.</td>
<td>No</td>
<td>No</td>
<td>BUPG: 2,<br />
all else: 1</td>
<td colspan="3">Proceed, with consideration of Deed Covenant &amp;
Reservation of Access</td>
<td></td>
</tr>
<tr class="even">
<td>Savannah Beach, GA</td>
<td>3/97 (Draft)</td>
<td>2/10-11/97</td>
<td>Private</td>
<td>Yes</td>
<td>No</td>
<td>BUPG: 3,<br />
all else: 1</td>
<td colspan="3">Proceed</td>
<td>A minor fuel leak occurred in 1996. Reported to have been cleaned
up.</td>
</tr>
<tr class="odd">
<td>Spokane, WA</td>
<td>6/98</td>
<td>12/5/96</td>
<td>U.S. Govt.</td>
<td>No</td>
<td>No</td>
<td>BUPG: 2,<br />
all else: 1</td>
<td colspan="3">Proceed, with consideration of Deed Covenant &amp;
Reservation of Access</td>
<td></td>
</tr>
<tr class="even">
<td>Summerfield, TX</td>
<td>7/98</td>
<td>3/6/97</td>
<td>Private</td>
<td>No</td>
<td>No</td>
<td>BUPG: 2,<br />
all else: 1</td>
<td colspan="3">Proceed</td>
<td></td>
</tr>
<tr class="odd">
<td>Whitney, NE</td>
<td>11/97</td>
<td>10/21/96</td>
<td>Private</td>
<td>No</td>
<td>No</td>
<td>BUPG: 2,<br />
all else: 1</td>
<td colspan="3">Proceed</td>
<td></td>
</tr>
<tr class="even">
<td colspan="11"><p>*Definition of All Category Assignments:</p>
<p>1 = No storage, release, or disposal of hazardous materials has
occurred and the area is not subject to migration from a release
nearby.</p>
<p>2 = Only storage of hazardous materials occurred in this specific
area.</p>
<p>3 = Contamination exists but is below the regulatory limit requiring
action.</p>
<blockquote>
<p>4 = Contamination existed but has been remediated to below the
regulatory action level.</p>
<p>7 = Further evaluation required.</p>
</blockquote>
<p>†Proceed=transfer of land is acceptable BUPG = backup power
generator</p></td>
</tr>
</tbody>
</table>

The standby generator requires storage of diesel fuel and uses
lubricating oil and antifreeze. The storage capacity for diesel fuel
would be about 500 gallons in one AST or 1,000 gallons in two ASTs,
which is below the SPCC threshold of 660 gallons in a single tank or
1,320 gallons in total; therefore, an SPCC Plan is not required by 40
CFR 112. The diesel fuel will be stored in ASTs with double walls or
secondary containment, greatly reducing the potential for leaks to the
environment. The amounts of lubricating oil and antifreeze used would be
minor and would not present a significant risk to the environment.

The USCG-like reference stations may use batteries to provide backup
power instead of a diesel fuel generator. Upon removal or replacement,
these batteries will likely be considered a hazardous waste and would be
sent to a waste facility that is licensed to accommodate this type of
waste.

Based on existing information, the FHWA plans to conduct additional
EDDAs for GWEN properties at Kirtland AFB, New Mexico, and Pueblo,
Colorado. If those studies find a low risk of contamination at those
properties, no significant hazards to construction or maintenance
personnel would result. If the FHWA analysis finds potential for
contamination at significant levels (i.e., regulatory action levels),
those sites would not be used. No significant impacts will result.

### Alternative B---Mix of GWEN sites and new sites using new equipment

The potential for the DGPS program to incur liabilities if this
alternative is implemented would be similar to that for Alternative A.
To prevent the assumption of liability for existing contamination at
properties acquired by the NDGPS program, the FHWA should perform EDDAs
in conformance with ASTM standards prior to acquiring those properties.

During construction and operation of the NDGPS reference stations, small
amounts of hazardous or regulated materials, such as petroleum fuels,
paints, solvents and cleaners, sealants, herbicides and pesticides, and
so on, would likely be used at the reference station properties. If
these materials are properly used in accordance with the manufacturer's
instruction, no contamination of the environment will result.

The USCG-like reference stations would likely use batteries for backup
power instead of a diesel-fuel generator. No diesel fuel would be stored
on site. Upon removal or replacement, these batteries would likely be
considered a hazardous waste and would be sent to a waste facility that
is licensed to accommodate this type of waste. No significant impacts
will result.

### Alternative C---All new sites using USCG-like equipment

Implementation of this alternative would result in the installation of
80 to 100 USCG-like reference stations. The potential for the NDGPS
program to incur liability because of the acquisition of contaminated
property and the potential for construction or operation of NDGPS
reference stations to cause significant contamination would be the same
as for Alternative B. No significant impacts will result.

### Alternative D---No-action alternative

Under this alternative, the NDGPS program would not acquire any property
or construct any facilities. There would be no potential for the program
to incur liability for contaminated property or to cause contamination.
No significant impacts will result.

## radiofrequency radiation environment and human exposure

### Alternative A (Preferred Action)---Mix of GWEN sites and equipment plus new sites and equipment

Under this alternative, 32 existing GWEN relay nodes would be converted
to GPS use, which would entail the removal of the GWEN transmitter and
the installation of a new DGPS transmitter and two new receive antennas.
Antennas, towers, and other equipment from 22 additional GWEN relay
nodes and 6 spare GWEN sets would also be relocated and installed at
newly constructed NDGPS reference stations. Finally, 7 NDGPS reference
stations would be newly constructed without use of GWEN sites or
equipment. In each of these cases, the NDGPS reference station would
include one transmit antenna and two smaller receive antennas. In regard
to the possible health effects of human exposure to RF radiation, only
the transmit antenna is of concern.

The NDGPS reference station transmits a signal at an ERP of 500 W and an
operating frequency of about 300 kHz. That signal generates electric and
magnetic fields in the vicinity of the transmit antenna that generally
decrease in field strength with increasing distance from the antenna. A
number of national and international standard-setting bodies, including
the American National Standards Institute (ANSI)/Institute of Electrical
and Electronic Engineers (IEEE), International Radiation Protection
Association (IRPA) of the World Health Organization, and the FCC, have
developed or adopted frequency-specific standards for occupational and
general public exposure to electromagnetic fields, such as those
generated by NDGPS transmissions. In the NDGPS operating band, the
safety standards define maximum permissible exposure (MPE) for both
electric and magnetic fields. Table 9 lists those MPEs, which are based
on a 6-minute averaging time. The ground-level electric and magnetic
fields that would be generated by the NDGPS transmitter are shown in
Table 10 (SRI International, 1998).

As shown by Tables 9 and 10, the NDGPS electric and magnetic fields
would exceed the national and international occupational safety
standards only within the inner 8 ft fence surrounding the transmit
tower and antenna. It is expected that the height of the security fence
and the barbed wire atop the fence would effectively discourage
trespassing. Signs will be posted warning the public to stay out of this
area. Authorized maintenance personnel will be instructed to make sure
the reference station is not transmitting when they enter this area.

+-----------------------+-----------------------+----------------------+
| Table 9\              |                       |                      |
| Safety Standards for  |                       |                      |
| Human Exposure to RFR |                       |                      |
| at an Operating       |                       |                      |
| Frequency of 300 kHz  |                       |                      |
+-----------------------+-----------------------+----------------------+
| Organization          | **MPE Level**         |                      |
+-----------------------+-----------------------+----------------------+
|                       | **Electric Field      | Magnetic Field (A/m) |
|                       | (V/m)**               |                      |
+-----------------------+-----------------------+----------------------+
| ANSI/IEEE\*           |                       |                      |
+-----------------------+-----------------------+----------------------+
| > Occupational        | 614                   | 54.33                |
+-----------------------+-----------------------+----------------------+
| > General Public      | 614                   | 54.33                |
+-----------------------+-----------------------+----------------------+
| IRPA                  |                       |                      |
+-----------------------+-----------------------+----------------------+
| > Occupational        | 614                   | 5.3                  |
+-----------------------+-----------------------+----------------------+
| > General Public      | 87                    | 2.5                  |
+-----------------------+-----------------------+----------------------+
| FCC                   |                       |                      |
+-----------------------+-----------------------+----------------------+
| > Occupational        | 614                   | 1.63                 |
+-----------------------+-----------------------+----------------------+
| > General Public      | 614                   | 1.63                 |
+-----------------------+-----------------------+----------------------+
| \*Adopted by the USAF |                       |                      |
| as Occupational       |                       |                      |
| Safety and Health     |                       |                      |
| Standard 48-9 (August |                       |                      |
| 1,1997) and the       |                       |                      |
| Department of Defense |                       |                      |
| as DOD Instruction    |                       |                      |
| 605.11 (February 21,  |                       |                      |
| 1995).                |                       |                      |
+-----------------------+-----------------------+----------------------+

  ------------------------------ ------------------- --------------------
  Table 10\                                          
  Ground Level Electric and                          
  Magnetic Fields at a Typical                       
  NDGPS Reference Station                            

  **\                            **Electric Field\   **Magnetic Field\
  Distance from base of tower    (V/m)**             (A/m)**
  (ft)**                                             

  2                              1,200               2.87

  30 (8 ft security fence)       80                  0.191

  100                            24                  0.057

  300 (40 ft perimeter fence)    8.0                 0.0191

  320 (equipment area)           7.5                 0.0179

  350 (boundary of site)         0.0164              0.0164

  Source: SRI International,                         
  1998                                               
  ------------------------------ ------------------- --------------------

The NDGPS magnetic field would not exceed the national and international
safety standards for exposure of the general public at any place outside
the inner 8 ft security fence. As noted above, public entry into that
fenced area is not expected. Outside the 8 ft security fence, the NDGPS
electric and magnetic fields will not exceed the ANSI/IEEE, IRPA, or FCC
safety standards for exposure of the general public to electric fields.

In addition to the possible health effects from absorption of RFR by the
human body, electromagnetic fields at the NDGPS operating frequency can
potentially shock an individual because of either: (1) flow of the
received electric field through his or her body touch, or (2) contact
with ungrounded metal objects within the field, thereby completing the
ground circuit and cause flow of electricity through his or her body.
The GWEN Final EIS identified a field strength of about 3,800 V/m as the
level necessary to produce sufficient current flow within the body to
cause discomfort to a person (USAF, 1987). At ground level, the NDGPS
electric field would be far less (at least an order of magnitude) than
one-tenth of that level and would not harm or cause discomfort to
persons in the vicinity.

The GWEN Final EIS also examined the situation in which a child touches
a van that has nonconducting rubber tires, causing flow of electricity
through the child's body and a shock to the child (USAF, 1987). The
NDGPS electric field would be sufficient to cause that shock only within
about 50 ft of the tower base. The shock would be startling but not
harmful to the child. To be harmed (i.e., burned) by current flow, the
child would have to grab a firm hold of a portion of the vehicle while
exposed to an electric field of 430 V/m or more (USAF, 1987). An
electric field of that strength would not occur outside the 8 ft
security fence. Adults are physically larger than children and would
require a more intense electric field to create the same current flows
as would occur in a child. The fences at the NDGPS reference stations
would be grounded and would not present a shock or burn hazard.

The measurements by the EPA and FCC at typical AM radio stations showed
that the electric and magnetic fields generated by such stations
decrease to levels well below the safety levels established by the
standards within a few hundred feet of the broadcast towers. The same
occurs for NDGPS reference stations. The cumulative level of RFR
exposure from an NDGPS reference station and another nearby radio
transmitter, even if directly adjacent to the NDGPS reference station,
would not create a health hazard in areas outside the inner fence of the
NDGPS reference station.

To address the potential for NDGPS reference stations to cause
electromagnetic interference (EMI) with other radio facilities using the
same frequency band, or a nearby band, the NTIA conducted a study of EMI
concerns (Lemmon and Ketchum, 1998). The coverage areas of NDGPS
reference stations, and hence the locations and number of stations
required to achieve nationwide coverage, depend on the ERPs of the
sites. The assignments of operating frequencies and ERPs to the
broadcast sites are constrained by the requirement that there be no
interference problems among DGPS signals or between DGPS signals and the
signals broadcast by other users of the 285 to 325 kHz band. These other
users include Canadian DGPS beacons, Canadian aviation beacons, Mexican
aviation beacons, FAA beacons, and radiobeacons licensed by the FCC. In
general, there would not be interference problems among DGPS beacons
that do not have cochannel frequency assignments. During the selection
of new sites for NDGPS reference stations, the government plans to avoid
areas where EMI is likely to occur. On the other hand, potential
interference problems do not appear to be entirely avoidable for any
choice of the number of sites, power levels, and frequency assignments.
Mutual EMI may result from operation of NDGPS reference stations and FAA
beacons located in the same vicinity. Based on a preliminary NTIA
analysis of possible locations for NDGPS reference stations having an
ERP of 300 W, three FAA beacons would suffer EMI under Phase I. Seven
FAA beacons may suffer EMI because of installation and operation of
NDGPS reference stations under Phase II. The number of FAA beacons
affected may change because of the proposed increase to 500 W ERP
transmission and any future changes in the location of NDGPS reference
stations. To prevent or minimize these EMI effects, the NTIA study
recommends that the operating frequency of the FAA beacons be changed to
provide frequency separation. Alternately, the ERP of the NDGPS
reference stations and/or the FAA beacons could be reduced in some cases
(Lemmon and Ketchum, 1998). Implementation of these measures to prevent
EMI would require coordination with the NTIA *Manual of Regulations and
Procedures for Federal Radio Frequency Management* (DOC NTIA, 1995), as
well as the FAA and other RF emitters. No significant impacts on public
health and no significant EMI with other systems would result.

### Alternative B---Mix of GWEN sites and new sites using new equipment.

The installation of all USCG-like DGPS equipment at both GWEN and newly
acquired NDGPS sites would not alter the anticipated level of impact
from RFR or shock from electromagnetic fields described under
Alternative A. Although Alternative A would use a mix of GWEN equipment
and USCG-like DGPS equipment, both types use the same transmit antenna,
which is the only component of concern with regard to possible health
effects from RFR exposure. Maximum ERP level would be 500 W for each
transmit antenna. No significant impacts on public health and no
significant EMI with other systems would result.

### Alternative C---All new sites using USCG-like equipment.

Under Alternative C, existing USCG equipment would be installed at all
proposed NDGPS sites. The transmit antenna used with existing USCG
equipment operates at a maximum 170 W ERP, resulting in a much lower
exposure level than from the GWEN and USCG-like DGPS transmit antenna.
Anticipated levels of impact, therefore, would be lower than those
described under Alternatives A and B. No significant impacts on public
health and no significant EMI with other systems would result.

### Alternative D---No-action alternative

Under this alternative, no actions would be taken to convert existing
GWEN relay nodes to NDGPS use, and no new NDGPS reference stations would
be built. There would be no new RF emissions. Existing RF emissions from
the existing GWEN relay nodes would occur in the future as long as the
USAF continued to operate the GWEN system. Because the USAF plans to
cease operation of the GWEN network in the near future, it is expected
that GWEN RF transmissions would end shortly. In any case, the findings
of the NRC study, which specifically addressed human exposure to RFR
from GWEN, confirm that no adverse effects on human health will result
from exposure to GWEN RFR (NRC, 1993). No significant impacts on public
health and no significant EMI with other systems would result.

## irreversible or irretrievable commitment of resources

This section represents an assessment of whether significant
irreversible or irretrievable commitment of resources would occur either
on a long-term or short-term basis. Long-term resources are permanent in
nature and include nonrenewable resources such as certain materials,
human labor, commodities, and natural resources. Short-term resources
are materials and labor used during construction. The following
assessment considers commitments for any of the three project
alternatives.

### Acceptance of GWEN Sites and Equipment 

The NDGPS program proposes to use existing materials, equipment, and
infrastructure from the GWEN program upon decommissioning of those USAF
assets. It allows the DOT to avoid committing resources to new equipment
or properties. This arrangement results in efficiencies in capital
expenditures, use of durable goods, and in human labor. Reuse of
materials would result in a minor direct benefit to the environment.
Useful materials would not be discarded prematurely to landfills, and
new materials would be spared for other uses. Economic trade-off
analyses indicate that the fiscal benefits over the life of the project
would far outweigh the short- and long-term commitments of resources and
capital to install, operate, and maintain an NDGPS service (NDGPS PIT,
1998).

### Personnel and Materials

The proposed NDGPS reference stations are unmanned and can be monitored
from a remote location for functional accuracy and reliability.
Personnel used during construction would result in an irretrievable
commitment; however, the number of workers and the expected duration of
equipment installation do not represent a significant expenditure,
regardless of the local or regional economy involved. Long-term use of
materials for NDGPS sites using new equipment and property would involve
the use of standard tower structures, electronic equipment, and
construction materials available commercially. These materials have the
potential for reuse, after NDGPS is decommissioned, for other purposes,
if necessary.

Maintenance and quality assurance activities would require a commitment
of human resources. Upon complete installation, only one or two
technicians or grounds maintenance personnel will visit the facility per
quarter. These visits typically involve inspection, cleaning, and
preventive maintenance of NDGPS subsystems, components, and hardware.
These activities are confined to the project area and do not require
major physical changes to the reference station. Hence, the life-cycle
effect of maintenance would not result in significant impacts to
environmental, socioeconomic, or cultural resources. During operation,
quality assurance monitoring would occur from remote locations using
existing levels or minor increases in personnel and monitoring
equipment.

### Decommissioning

If used for the full project life of the NDGPS program, approximately 15
years, most or all of the resources committed to the project would be
either obsolete or structurally inferior for reuse. Decommissioning
would be performed according to applicable federal environmental
regulations and established USCG protocols in force at that time. A
commitment of human resources is required to decommission the
facilities, remove materials and equipment, and restore the property.
This commitment of resources, similar to project installation, is not
considered significant.

#  mitigation measures

For NDGPS reference stations proposed at new (non-GWEN) properties, no
significant environmental impacts are anticipated from the
implementation of either the preferred action or any of the alternative
actions provided that sensitive environmental resources or conditions
are avoided during site selection. Environmental site-selection criteria
will be applied and agency consultation performed as part of the
proposed action to ensure that unforeseeable, site-specific adverse
impacts will not be significant. The environmental site selection
criteria for new sites and agency consultation and mitigation measures
to be taken for all NDGPS sites are summarized in Table 11 and discussed
in Section 6. If impact avoidance cannot be achieved, specific
mitigation measures including agency consultation will be taken by the
FHWA to reduce any potentially significant impacts to less than
significant levels.

For NDGPS reference stations proposed at existing GWEN properties, no
environmental resources or conditions will be significantly affected;
however, confirmation of this assessment at the site-specific level
would be required for the following resources or conditions: flora and
fauna, cultural resources, land use, and RF effects (see Table 11). To
confirm that no potentially significant impact to these resources will
occur, consultation with appropriate resource agencies, and possibly
other mitigation measures, will be performed as necessary.

To the extent possible, FHWA plans to adhere to the environmental siting
criteria and/or implement the mitigation measures identified herein in
order to eliminate all significant adverse environmental effects. Only
in the unlikely situation that planned mitigation measures cannot be
undertaken or would not be effective, would additional site-specific
NEPA analysis and mitigation be prepared by the FHWA.

Table 11 is designed to assist the FHWA in selecting sites for NDGPS
reference stations and determining the proper level of environmental
review for those sites. Avoidance during site selection is the primary
means of preventing significant impacts. If avoidance through site
selection is not possible, mitigation measures indicated herein will be
implemented as needed at new sites or at GWEN sites proposed for use as
NDGPS reference stations.

+-----------+----------------+-------------------+-------------------+
| Table 11  |                |                   |                   |
|           |                |                   |                   |
| Envi      |                |                   |                   |
| ronmental |                |                   |                   |
| Siting    |                |                   |                   |
| Criteria  |                |                   |                   |
| and       |                |                   |                   |
| Con       |                |                   |                   |
| sultation |                |                   |                   |
| and       |                |                   |                   |
| M         |                |                   |                   |
| itigation |                |                   |                   |
| Measures\ |                |                   |                   |
| for NDGPS |                |                   |                   |
| F         |                |                   |                   |
| acilities |                |                   |                   |
| at New    |                |                   |                   |
| Locations |                |                   |                   |
| and GWEN  |                |                   |                   |
| Locations |                |                   |                   |
+-----------+----------------+-------------------+-------------------+
| **\       | Environmental  | Consultation and  |                   |
| \         | Siting         | Mitigation        |                   |
| \         | Criteria for   |                   |                   |
| R         | New Sites      |                   |                   |
| esource** |                |                   |                   |
+-----------+----------------+-------------------+-------------------+
|           |                | New Sites         | GWEN Sites        |
+-----------+----------------+-------------------+-------------------+
| Geology\  | Avoid unstable | Apply standard    | Apply standard    |
| (see §    | slopes and     | erosion control   | erosion control   |
| 6.1)      | highly         | measures          | measures          |
|           | erodible or    |                   |                   |
|           | eroded soils   |                   |                   |
+-----------+----------------+-------------------+-------------------+
|           | Avoid          | Compensate for    | None              |
|           | conflicts with | loss of access to |                   |
|           | mineral rights | resource          |                   |
|           | and known      |                   |                   |
|           | mineral        |                   |                   |
|           | deposits       |                   |                   |
|           | (including oil |                   |                   |
|           | and gas)       |                   |                   |
+-----------+----------------+-------------------+-------------------+
|           | Avoid areas    | Monitor during    | None              |
|           | known or       | construction      |                   |
|           | expected to    | using a qualified |                   |
|           | contain        | paleontologist    |                   |
|           | p              |                   |                   |
|           | aleontological |                   |                   |
|           | resources      |                   |                   |
+-----------+----------------+-------------------+-------------------+
|           |                |                   |                   |
+-----------+----------------+-------------------+-------------------+
| Water     | Avoid areas    | Apply lime to     | Evaluate          |
| Quality\  | with           | acidic soil;\     | conditions at     |
| (see      | seasonally     | evaluate          | decommissioning   |
| §6.2)     | high ground    | conditions at     |                   |
|           | water and      | decommissioning   |                   |
|           | acidic soils,  |                   |                   |
|           | or set back    |                   |                   |
|           | copper ground  |                   |                   |
|           | plane \>300 ft |                   |                   |
|           | from surface   |                   |                   |
|           | water          |                   |                   |
+-----------+----------------+-------------------+-------------------+
|           |                |                   |                   |
+-----------+----------------+-------------------+-------------------+
| Ecol      | Avoid          | Obtain USACE      | None              |
| ogically\ | federal-       | dredge and fill   |                   |
| Sensitive | jurisdictional | permit and/or     |                   |
| Areas\    | wetlands       | compensate for    |                   |
| (see §    |                | loss of wetlands  |                   |
| 6.3)      |                |                   |                   |
+-----------+----------------+-------------------+-------------------+
|           | Avoid the      | Raise facilities  | None              |
|           | 100-year       | above 100-year    |                   |
|           | floodplain     | flood level or    |                   |
|           |                | flood-proof       |                   |
|           |                | facilities        |                   |
+-----------+----------------+-------------------+-------------------+
|           |                |                   |                   |
+-----------+----------------+-------------------+-------------------+
| Air       | None           | Obtain local      | Obtain local      |
| Quality\  |                | permits for BUPG; | permits for BUPG; |
| (see §    |                | suppress dust     | suppress dust     |
| 6.4)      |                | emissions during  | emissions during  |
|           |                | construction      | construction      |
+-----------+----------------+-------------------+-------------------+
|           |                |                   |                   |
+-----------+----------------+-------------------+-------------------+
| Noise\    | None           | Equip the BUPG    | Equip the BUPG    |
| (see §    |                | with silencer;    | with silencer;    |
| 6.5)      |                | limit             | limit             |
|           |                | construction to   | construction to   |
|           |                | normal working    | normal working    |
|           |                | hours and shut    | hours and shut    |
|           |                | off equipment     | off equipment     |
|           |                | when not in use   | when not in use   |
+-----------+----------------+-------------------+-------------------+
|           |                |                   |                   |
+-----------+----------------+-------------------+-------------------+
|           |                |                   |                   |
+-----------+----------------+-------------------+-------------------+
| Table 11  |                |                   |                   |
| (c        |                |                   |                   |
| ontinued) |                |                   |                   |
|           |                |                   |                   |
| Envi      |                |                   |                   |
| ronmental |                |                   |                   |
| Siting    |                |                   |                   |
| Criteria  |                |                   |                   |
| and       |                |                   |                   |
| Con       |                |                   |                   |
| sultation |                |                   |                   |
| and       |                |                   |                   |
| M         |                |                   |                   |
| itigation |                |                   |                   |
| Measures\ |                |                   |                   |
| for NDGPS |                |                   |                   |
| F         |                |                   |                   |
| acilities |                |                   |                   |
| at New    |                |                   |                   |
| Locations |                |                   |                   |
| and GWEN  |                |                   |                   |
| Locations |                |                   |                   |
+-----------+----------------+-------------------+-------------------+
| Resource  | Environmental  | Consultation and  |                   |
|           | Siting         | Mitigation        |                   |
|           | Criteria for   |                   |                   |
|           | New Sites      |                   |                   |
+-----------+----------------+-------------------+-------------------+
|           |                | New Sites         | GWEN Sites        |
+-----------+----------------+-------------------+-------------------+
| Visual    | Avoid areas    | None              | None              |
| R         | within view of |                   |                   |
| esources\ | moderately to  |                   |                   |
| (see §    | highly         |                   |                   |
| 6.6)      | sensitive      |                   |                   |
|           | public use     |                   |                   |
|           | areas          |                   |                   |
+-----------+----------------+-------------------+-------------------+
|           | Avoid          | None              | None              |
|           | designated or  |                   |                   |
|           | candidate wild |                   |                   |
|           | and scenic     |                   |                   |
|           | river areas    |                   |                   |
+-----------+----------------+-------------------+-------------------+
|           |                |                   |                   |
+-----------+----------------+-------------------+-------------------+
| Flora and | Avoid critical | Consult with      | Consult with      |
| Fauna\    | habitat for    | USFWS and state   | USFWS and state   |
| (see §    | threatened and | agencies          | agencies          |
| 6.7)      | endangered     | regarding         | regarding         |
|           | species        | protected         | protected         |
|           |                | species; alter    | species; alter    |
|           |                | facility layout   | facility layout   |
|           |                | to reduce level   | to reduce level   |
|           |                | of impact         | of impact         |
+-----------+----------------+-------------------+-------------------+
|           | Avoid critical | Consult with      | Consult with      |
|           | avian habitats | USFWS regarding   | USFWS regarding   |
|           | and vicinity   | MBTA; mark tower, | MBTA; mark tower, |
|           | within major   | guy wires and     | guy wires and     |
|           | flyways        | overhead power    | overhead power    |
|           |                | lines             | lines             |
+-----------+----------------+-------------------+-------------------+
|           | Avoid rare     | Consult with      | Consult with      |
|           | native plant   | state agencies    | state agencies    |
|           | communities    | and natural       | and natural       |
|           |                | heritage          | heritage          |
|           |                | database; conduct | database; conduct |
|           |                | survey and alter  | survey and alter  |
|           |                | site layout to    | site layout to    |
|           |                | avoid rare plants | avoid rare plants |
+-----------+----------------+-------------------+-------------------+
|           |                |                   |                   |
+-----------+----------------+-------------------+-------------------+
| Cultural  | Avoid siting   | Consult with      | Consult with      |
| R         | on properties  | SHPO; perform     | SHPO; perform     |
| esources\ | listed or      | data recovery per | data recovery per |
| (see §    | eligible for   | consultation with | consultation with |
| 6.8)      | listing on the | SHPO and ACHP     | SHPO and ACHP     |
|           | NRHP or within |                   |                   |
|           | 1.5 mi of      |                   |                   |
|           | historic       |                   |                   |
|           | properties     |                   |                   |
|           | with high      |                   |                   |
|           | visual         |                   |                   |
|           | sensitivity    |                   |                   |
+-----------+----------------+-------------------+-------------------+
|           | Avoid          | Consult with      | None              |
|           | resources or   | traditional       |                   |
|           | properties of  | cultural leaders  |                   |
|           | significance   | on appropriate    |                   |
|           | to Native      | methods to reduce |                   |
|           | Americans      | potential impacts |                   |
+-----------+----------------+-------------------+-------------------+
|           |                |                   |                   |
+-----------+----------------+-------------------+-------------------+
| Re        | Avoid          | None              | None              |
| creation\ | national,      |                   |                   |
| (see      | state,         |                   |                   |
| §6.9)     | regional, and  |                   |                   |
|           | local parks    |                   |                   |
|           | and recreation |                   |                   |
|           | areas          |                   |                   |
+-----------+----------------+-------------------+-------------------+

+-----------+----------------+-------------------+-------------------+
| Table 11  |                |                   |                   |
| (c        |                |                   |                   |
| oncluded) |                |                   |                   |
|           |                |                   |                   |
| Envi      |                |                   |                   |
| ronmental |                |                   |                   |
| Siting    |                |                   |                   |
| Criteria  |                |                   |                   |
| and       |                |                   |                   |
| Con       |                |                   |                   |
| sultation |                |                   |                   |
| and       |                |                   |                   |
| M         |                |                   |                   |
| itigation |                |                   |                   |
| Measures\ |                |                   |                   |
| for NDGPS |                |                   |                   |
| F         |                |                   |                   |
| acilities |                |                   |                   |
| at New    |                |                   |                   |
| Locations |                |                   |                   |
| and GWEN  |                |                   |                   |
| Locations |                |                   |                   |
+-----------+----------------+-------------------+-------------------+
| Resource  | Environmental  | Consultation and  |                   |
|           | Siting         | Mitigation        |                   |
|           | Criteria for   |                   |                   |
|           | New Sites      |                   |                   |
+-----------+----------------+-------------------+-------------------+
|           |                | New Sites         | GWEN Sites        |
+-----------+----------------+-------------------+-------------------+
| Land Use\ | Avoid areas    | Consult with      | Consult with      |
| (see §    | where NDGPS    | local planning    | local planning    |
| 6.10)     | would conflict | jurisdiction;     | jurisdiction;     |
|           | with land-use  | alter facility    | alter facility    |
|           | plans or local | design to reduce  | design to reduce  |
|           | zoning         | or eliminate      | or eliminate      |
|           |                | potential         | potential         |
|           |                | conflict          | conflict          |
+-----------+----------------+-------------------+-------------------+
|           | Avoid          | Complete Farmland | None              |
|           | designated     | Conversion Impact |                   |
|           | prime, unique, | Rating form       |                   |
|           | or state- or   |                   |                   |
|           | lo             |                   |                   |
|           | cal-importance |                   |                   |
|           | farmland       |                   |                   |
+-----------+----------------+-------------------+-------------------+
|           | Avoid state    | Alter facility    | None              |
|           | and federal    | design to reduce  |                   |
|           | lands where    | or eliminate      |                   |
|           | management     | potential         |                   |
|           | plans are      | conflict          |                   |
|           | incompatible   |                   |                   |
|           | with NDGPS     |                   |                   |
+-----------+----------------+-------------------+-------------------+
|           | Avoid          | Alter facility    | None              |
|           | conflicts with | design to reduce  |                   |
|           | approved state | or eliminate      |                   |
|           | and local      | potential         |                   |
|           | coastal zone   | conflict          |                   |
|           | management     |                   |                   |
|           | plans          |                   |                   |
+-----------+----------------+-------------------+-------------------+
|           |                |                   |                   |
+-----------+----------------+-------------------+-------------------+
| Socio     | None           | Supply temporary  | None              |
| economics |                | housing for       |                   |
| &         |                | construction      |                   |
| Envi      |                | workers if needed |                   |
| ronmental |                |                   |                   |
| Justice\  |                |                   |                   |
| (see §    |                |                   |                   |
| 6.11)     |                |                   |                   |
+-----------+----------------+-------------------+-------------------+
|           |                |                   |                   |
+-----------+----------------+-------------------+-------------------+
| Energy\   | None           | None              | None              |
| (see §    |                |                   |                   |
| 6.12)     |                |                   |                   |
+-----------+----------------+-------------------+-------------------+
|           |                |                   |                   |
+-----------+----------------+-------------------+-------------------+
| Hazardous | None           | Prepare EDDAs     | Prepare EDDAs at  |
| M         |                |                   | Kirtland AFB, NM, |
| aterials\ |                |                   | and Pueblo, CO,   |
| (see §    |                |                   | GWEN relay nodes  |
| 6.13)     |                |                   |                   |
+-----------+----------------+-------------------+-------------------+
|           |                |                   |                   |
+-----------+----------------+-------------------+-------------------+
| Radio     | Avoid areas    | Consult with      | Consult with      |
| frequency | near other     | NTIA; analyze     | NTIA; analyze     |
| Effects\  | radio          | assigned          | assigned          |
| (see §    | facilities     | frequency for     | frequency for     |
| 6.14)     | where EMI is   | EMI/EMC; reassign | EMI/EMC; reassign |
|           | possible       | operating         | operating         |
|           |                | frequencies; or   | frequencies; or   |
|           |                | reduce ERP        | reduce ERP        |
+-----------+----------------+-------------------+-------------------+
|           | None           | Maintain security | Maintain security |
|           |                | fences and signs  | fences and signs  |
|           |                | to warn of RF     | to warn of RF     |
|           |                | exposure hazard   | exposure hazard   |
+-----------+----------------+-------------------+-------------------+

#  

# COnclusion

This PEA, prepared for a network of NDGPS reference stations, supports
the conclusion that potentially significant environmental impacts can
either be avoided during site selection or mitigated via appropriate
mitigation measures. No significant site-specific environmental impacts
will occur as a result of implementation of the preferred or alternative
actions.

For NDGPS reference stations proposed at existing GWEN properties, no
environmental resources or conditions will be significantly affected;
however, confirmation of this assessment will be performed at the
site-specific level for the following resources or conditions: flora and
fauna, cultural resources, land use, and RF effects. To confirm that no
potentially significant impacts to these resources will occur,
consultation with appropriate resource agencies, and implementation of
other mitigation measures, will be undertaken.

For proposed NDGPS reference stations proposed on other (non-GWEN)
properties, it is anticipated that potentially significant impacts can
be avoided during the selection of candidate sites. Specific
environmental siting criteria are described in this document that will
allow the FHWA to avoid potentially significant impacts. For
environmental siting criteria that cannot be met during the
site-selection phase, mitigation measures will be taken to reduce or
eliminate any potentially significant environmental impact to an
insignificant level. To confirm that no potentially significant impacts
to these resources will occur, consultation with appropriate resource
agencies, and implementation of mitigation measures, will be undertaken.

Implementing the preferred action or any of the alternative actions
would not result in a direct taking or constructive use of lands
protected by Section 4(f) of the DOT Act.

A Finding of No Significant Impact (FONSI) is recommended at the
programmatic level for the deployment of NDGPS reference stations.

#  {#section-32 .heading0}

#  {#section-33 .heading0}

#  {#section-34 .heading0}

#  {#section-35 .heading0}

#  {#section-36 .heading0}

# THIS PAGE INTENTIONALLY LEFT BLANK  {#this-page-intentionally-left-blank-6 .heading0}

#  references

Advisory Council on Historic Preservation and the GSA Interagency
Training Center. *Introduction to Federal Projects and Historic
Preservation Law, Participant's Desk Reference* (January 1991).

Allen, Leonard W., III. *United States' Nationwide Differential Global
Positioning System*, Alexandria: United States Coast Guard (1998).

ANSI/IEEE C95.1.1991. *IEEE Standard for Safety Levels with Respect to
Human Exposure to Radio Frequency Electromagnetic Fields, 3kHz to 300
GHz,* New York: Institute of Electrical and Electronics Engineers
(1992).

Avery, M., P. F. Springer, and J.F. Cassel. "The Effects of a Tall Tower
on Nocturnal Bird Migration -- a Portable Ceilomenter Study," *Auk*,
Vol. 93 (1976), 281-291.

Bolt, Beranek, and Newman. *Noise from Construction Equipment and Home
Appliances,* Environmental Protection Agency (December 31, 1971).

Bradley, J. W. "Differential Global Positioning Services and Traffic
Services," *Differential Corrections, Inc.* (1995),
<http://www.dgps.com/>, 5 June 1998.

Bureau of Land Management. *Visual Resource Management Program,* Bureau
of Land Management Manual Series 8400, Handbooks 8410 and 8431-1, GPO
No. 024-011-00116-6, Washington, DC:, Department of the Interior (1986).

Council on Environmental Quality. *Environmental Justice, Guidance Under
the National Environmental Policy Act* (December 10, 1997).

Council on Environmental Quality. "Regulations on Implementing National
Environmental Policy Act Procedures," 40 *Code of Federal Regulations,*
1500--1508 (1986).

Crawford, R. L. "Bird Casualties at a Leon County, Florida TV Tower: A
25-year Migration Study," *Bulletin of Tall Timbers Research Station,*
No. 22 (1981).

Department of Transportation. "Department of Transportation Order to
Address Environmental Justice in Minority Populations and Low-Income
Populations," *Federal Register*. Volume 62, Number 72 (April 15, 1997).

Differential Corrections, Inc. "DGPS Architecture Based on Separating
Error Components, Virtual Reference Stations and FM Subcarrier
Broadcast," (1995), <http://www.dgps.com/>, 5 June 1998.

EMC Engineering Services, Inc. *Testing for Copper and Cursory Review of
Aquatic Fauna, Proposed NDGPS Facility, Pembroke, Bryan County,
Georgia,* by Mike S. Ruth, PG and David R. Crawley, EMC Project No.
98-420.30, August 21, 1998.

Environmental Protection Agency. "National Ambient Air Quality
Standards," 43 *Federal Register* 8962 (1978).

Environmental Protection Agency. "Federal Radiation Protection Guidance,
Proposed Alternatives for Controlling Public Exposure to Radiofrequency
Radiation, Notice of Proposed Recommendations," *Federal Register* (Part
II), 51 (146) (1986), 27318--27339.

Environmental Protection Agency (EPA). "Toxics criteria for those states
not complying with Clean Water Act section 303 (c) 2 (B)," 40 *Code of
Federal Regulations* 131.36, (July 1, 1997).

Environmental Protection Agency (EPA). "National Primary and Secondary
Drinking Water Regulations," Office of Ground Water and Drinking Water
(August 21, 1998), http://www.epa.gov/OGWDW, 9 September 1998.

Federal Communications Commission (FCC). "Evaluating Compliance with FCC
Guidelines for Human Exposure to Radiofrequency Electromagnetic Fields,"
Office of Engineering and Technology (OET) Bulletin 65 (1997).

Federal Highway Administration (FHWA). *Guidance for Preparing and
Processing Environmental and Section 4(f) Documents,* Technical Advisory
T 6640.8A (October 30, 1987),
[http://www.fhwa.dot.gov](http://www/fhwa.dot.gov).

Federal Highway Administration (FHWA). "Environmental Impact and Related
Procedures: Right-of-Way and Environment," 23 *Code of Federal
Regulations* 771 (1987),
[http://www.fhwa.dot.gov](http://www/fhwa.dot.gov).

Federal Highway Administration (FHWA). Environmental Policy Statement
1994, "A Framework to Strengthen the Linkage between Environmental and
Highway Policy," http://www.fhwa.dot.gov/region3/.

International Conference of Building Officials. *Uniform Building Code*
(1997).

Jaroslow, B.N. *A Review of Factors Involved in Bird-Tower Kills, and
Mitigative Procedures,* paper presented at the Mitigation Symposium,
Colorado State University (July 16--20, 1979).

Joint U.S. Department of Defense/U.S. Department of Transportation Task
Force. *The Global Positioning System: Management and Operation of a
Dual Use System,* Washington, DC (December 1993).

Ketchum, R. L., J. J. Lemmon, and J. R. Hoffman. *Site Selection Plan
and Installation Guidelines for a Nationwide Differential GPS Service,*
Boulder, CO: National Telecommunications and Information Administration
(1997), also available from the Turner-Fairbank Highway Research Center
Web site at <http://www.tfhrc.gov/>.

Lemmon, J. J., and R. L. Ketchum. "Performance Parameter Tradeoff
Analysis for a Nationwide Differential GPS Service," *Turner-Fairbank
Highway Research Center*, <http://www.tfhrc.gov/> 30 July 1998.

National Park Service (NPS). "National Register Information System,"
<http://www.nr.nps.gov/nrishome.html>, updated 4 June 98.

National Park Service. "Guidelines for Applying the National Register
Criteria for Evaluation," *National Register Bulletin 15* (June 1,
1982).

National Research Council. *Assessment of the Possible Health Effects of
Ground Wave Emergency Network* (1993).

Natural Resources Conservation Service (NRCS). "State of the Land---1992
National Resources Inventory (May 1994),"
<http://www.nhq.nrcs.usda.gov/land/home.html>, 16 July 1998.

NDGPS Policy and Implementation Team. *Nationwide DGPS Report: Rationale
for the Development of a DGPS Policy and Implementation Plan for a
Nationwide DGPS Service,* Rockville, MD: PB Farradyne, Inc. (March 24,
1998).

Office of Science and Technology Policy. *Fact Sheet: U.S. Global
Positioning System Policy,* The White House (March 29, 1996),
<http://gauss.gge.unb.ca/policy/Fact_Sheet>, 3 June 1998.

President, Executive Order. "Protection of Children," Executive Order
13045, 62 *Federal Register* No. 78, 19883 (April 23, 1997).

President, Executive Order. "Federal Actions to Address Environmental
Justice in Minority Populations and Low-income Populations," Executive
Order 12898, 11 February, 1994. 59 *Federal Register* No. 32, 3685
(1994).

President, Executive Order. "Floodplain Management," Executive Order
11988,
<http://www.usace.army.mil/inet/functions/cw/cecwo/reg/eo11988.html>, 24
May 1977.

Pugh, Ted. Personal communication (August 1998).

SRI International. *National Environmental Policy Act Compliance for the
Nationwide Differential Global Positioning System (DGPS) Program (Task
Assignment 9605.SRI.1),* Menlo Park, CA: SRI International (May 27,
1998).

U.S. Air Force. *Electromagnetic Radiation Hazards,* Air Force
Communications Service (E-1 Standard) Technical Manual, T.O. 312-10-4
(1971).

U.S. Air Force. "Explosives Safety Standards," AF Regulation 127-100
(C1), (1982).

U.S. Air Force. *Final Environmental Impact Statement, Final Operational
Capability, Ground Wave Emergency Network,* Hanscom Air Force Base, MA:
Air Force Systems Command, Electronic Systems Division (September 1987).

U.S. Air Force. *Finding of No Significant Impact,* "Closure of the
Chico Ground Wave Emergency Network (GWEN) Site, Chico, California," Air
Combat Command Headquarters, Environmental Leadership Board, 5 October
1995.

U.S. Army Corps of Engineers. "Nationwide Permit Program," 33 *Code of
Federal Regulations* 330, (July 1, 1998).

U.S. Army Corps of Engineers. "Procedures for Implementing NEPA," 33
*Code of Federal Regulations* 230, (July 1, 1997).

U.S. Coast Guard. *Feasibility Report: Conversion of U.S. Air Force
Ground Wave Emergency Network (GWEN) Site #722 Appleton, WA to U.S.
Coast Guard Differential Global Positioning (DGPS) Operation,*
Electronic Engineering Center, Differential GPS Branch (March 7, 1997).

U.S. Coast Guard. *Differential Global Positioning System Navigation
Service Concept of Operations*, COMDTINST 16577.2 (16 August 1995).

U.S. Coast Guard. *National Environmental Policy Act: Implementing
Procedures and Policy for Considering Environmental Impacts,* COMDTINST
M16475.1C.

U.S. Congress. Public Law 89-670, *An Act to Establish a Department of
Transportation and for Other Purposes* (October 15, 1966).

U.S. Congress. Public Law 105-66, *Department of Transportation and
Related Agencies Appropriations Act, 1998* (October 27, 1997).

U.S. Department of Commerce (DOC), National Telecommunications and
Information Administration (NTIA). *A Technical Report to the Secretary
of Transportation on a National Approach to Augmented GPS Services,*
NTIA Special Publication 94-30 (December 1994).

U.S. Department of Commerce, National Telecommunications and Information
Administration. *Manual of Regulations and Procedures for Federal Radio
Frequency Management*, May 1992 Edition, revised January 1995.

U.S. Department of Defense, U.S. Department of Commerce, and U.S.
Department of Transportation. *Memorandum of Agreement for the
Establishment and Operation of the Nationwide Differential Global
Positioning System (NDGPS),* Version 6, (July 1998).

U.S. Department of the Interior, Bureau of Mines. *State Mineral
Summaries* (1991).

U.S. Department of Transportation. "Department of Transportation Order
to Address Environmental Justice in Minority Populations and Low-Income
Populations," *Federal Register*, Vol 62 (April 15, 1997) 18377--18381.

U.S. Department of Transportation, and U.S. Department of Defense. *1996
Federal Radionavigation Plan*, Report Number
DOT-VNTSC-RSPA-97-2/DOD-4650.5 (July 1997).

U.S. Geological Survey. *Ground Water Atlas of the United States,*
[http://wwwcapp.er.usgs.gov/publicdocs/gwa/](http://wwwcapp.er.usgus.gov/publicdocs/gwa/)
23 October 1998.

# List of preparers

Patricia L. Burns, Director, Envirotechnical Program, SRI International.

John A. Chamberlain, Environmental Consultant, Envirotechnical Program,
SRI International.

William A. Edson, Senior Principal Engineer, Radio Science and
Engineering Division, SRI International.

James Manitakos, Jr., Senior Environmental Consultant, Envirotechnical
Program, SRI International.

Jeannette Nishida, Environmental Consultant, Envirotechnical Program,
SRI International.

#   {#section-37 .heading0}

#  {#section-38 .heading0}

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#  {#section-45 .heading0}

# APPENDIX A {#appendix-a .heading0}

# DRAFT MEMORANDUM OF AGREEMENT {#draft-memorandum-of-agreement .heading0}

# for the establishment and operation of the  {#for-the-establishment-and-operation-of-the .heading0}

# nationwide differential global positioning system (NDGPS)  {#nationwide-differential-global-positioning-system-ndgps .heading0}

#  {#section-46 .heading0}

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#  {#section-48 .heading0}

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# APPENDIX B {#appendix-b .heading0}

# draft MEMORANDUM OF AGREEMENT for compliance with the {#draft-memorandum-of-agreement-for-compliance-with-the .heading0}

# national environmental policy act for the establishment of the {#national-environmental-policy-act-for-the-establishment-of-the .heading0}

# nationwide differential global positioning system service  {#nationwide-differential-global-positioning-system-service .heading0}

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# APPENDIX C {#appendix-c .heading0}

# GWEN RELAY NODES AND OTHER (NON-GWEN) SITES PROPOSED {#gwen-relay-nodes-and-other-non-gwen-sites-proposed .heading0}

# FOR NDGPS USE  {#for-ndgps-use .heading0}

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# APPENDIX D {#appendix-d .heading0}

# distribution list for the notice of availability---ndgps draft programmatic environmental assessment  {#distribution-list-for-the-notice-of-availabilityndgps-draft-programmatic-environmental-assessment .heading0}

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