3.3

TVA's Fontana Dam Visitor Center offers hot showers and picnic tables. The lake has boat docks and
launching ramps. Fishing is popular at Fontana Lake with its abundant supply of rainbow trout
(Oncorhynchus mykiss), brown trout (Salmo trutta), brook trout (Salvelinus fontinalis), largemouth bass
(Mic�opterus saln�oides), smallmouth bass (M. dolomieu), walleye (Sander vitreus), pike (Esox lucius),
perch (Perca.flavescens), sunfish (Lepo�nis sp.), and crappie (Pomoxis nigromaculatus). The historic
Fontana Village Resort is a year-round vacation spot whose appeal is in part due to its location adjacent to
GSMNP.
3.3 Existing Physical Environment
3.3.1 Topography, Geology, and Soils
The study area involves mountainous terrain with high ridges, steep slopes, and deep ravines. A
considerable topographic relief of 3,650 ft (1,113 m) occurs across the study area. The geologic setting of
the study area consists of highly deformed metamorphic Precambrian sedimentary rocks. These rocks have
been folded and faulted in multiple uplift episodes, and the orientation of these rocks is highly variable. Area
soils are derived from in-situ weathering of the parent rock; the steep slopes do not allow far thick soil
development. Both the rock and soil contain sulfide minerals, which can produce acid drainage when
disturbed and exposed to oxygen and water. The following paragraphs summarize these existing conditions,
and a more detailed report is included in Appendix I.
The terrain of the alternative corridors consists primarily of steep peaks, ridges and mountains with
alternating ravines and benches. Specifically, this region consists of three distinct topographic settings.
Broad to narrow flats form floodplains which have been incised by rivers and streams. Rolling hills and
moderate slopes are found on lower intermediate mountains and side ridges. Finally, steep slopes are found
on the larger high mountain divides. The elevations range from approximately 1,275 ft(389 m) msl to
approximately 5,000 ft (1,524 m) msl.
The study area lies within the Blue Ridge pbysiographic province of North Carolina. Locally within the
alternative corridors, the rocks are comprised primarily of inetamorphic Precambrian sedimentary rocks of
the Ocoee Supergroup. This group of rocks includes slates, phyllites, schists, and quartzites — all with
varying degrees of inetamorphism. Approximately 10 mi (16 km) south, the Cherohala Skyway was
constructed in the same group of rocks (Appendix L). During construction, it was realized that rocks of the
Ocoee Supergroup contained enough iron-sulfide minerals to produce acid drainage when disturbed. This
chemical reaction is caused when sulfide minerals oxidize resulting in the production of sulfuric acid, sulfate
salts, and iron hydroxide. The pH of the drainage can vary from 2.0 to 4.5, which is acidic enougb to
degrade the remaining ininerals in the rocks. Some rocks within the corridors contain heavy metal minerals
(i.e., copper, lead, and zinc). When disturbed, these minerals can leach from the rock, mobilize, and
concentrate to furkher degrade the quality of the drainage.
Two Ocoee Supergroup rock formations underlie the alternative corridors, the Copperhill Formation and the
slate of the Copperhill Formation. The Copperhill Formation is priinarily a light gray, coarse- and medium-
grained, feldspathic metasandstone or metagraywacke with minar proportions of a graphitic and sulfidic
mica schist. The Slate of the Copperhill Formation consists of dark-gray to black, graphitic, sulfidic slate,
Affected Environment — 3-26
North Shore Road Final Environmental Impact Statement

phyllite and schist, and this formation contains the heavy metal bearing sulfide deposits associated with the
Swain County copper districts.
Some of the study area's underlying rocks are known to contain "black shales" or monazite deposits.
Monazite contains varying levels of variety elements, such as thorium and uranium, which are radioactive.
Such rocks have been termed NORMs — Naturally Occurring Radioactive Materials (Kohn 2005).
Structural deformation has occurred across the entire study area. A typical section through this area shows
an undulating surface of alternating anticlines and synclines separated by occasional faults. This
deformation is the result of multiple mountain-building episodes that have occurred throughout. Regional
strike is generally northeast/southwest, but it is highly variable across the site depending on proximity of the
immediate structural feature. Regional dip direction is southeast or northwest depending on which limb of
the fold is being oriented. Dip angles can be as great as 90 degrees, and numerous overiurned beds occur
throughout the corridars.
The soils along the study corridors are broken into three major series of soiL These soils are a product of the
natural weathering of the parent rocks and have been modified by the site topography, vegetation, erosion
and climate. The soils include but are not exclusive to the Junaluska, Soco, and Spivey-Cataska series. The
soils are rypically found in mountainous topography with thin ridges, narrow valleys and steep slopes. Each
soil is very acidic due to the weathering of the sulfide minerals contained in the parent rocks. The Junaluska
series forms from weathering of the Copperhill formation. These soils are generally found along the
northern shoreline of Fontana Lake. The soil taxonomy is fine loamy, mixed, sub-active, mesic Typic
Hapludults. The Soco soils are weathered from coarse grained low-grade metasedimentary rocks such as
metasandstone and metagraywacke, occasionally interbedded with phyllite or slate. The soil taxonomy is
coarse-loamy, mixed, active, mesic Typic Dystrudepts. The Spivey-Cataska soils are formed from the
weathering of the slate of the Copperhill Formation which includes low-grade metasedimentary rocks such
as siltstone, slate, and phyllite. These soils are found in a thin band trending northeast from Fontana Dam.
The soil taxonomic class is loamy skeletal, semiactive, mesic, Typic and Humic Dystrudepts.
3.3.2 Floodplains
Executive Order (EO) 11988, Floodplain Management, 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" (Carter 1977). Development of floodplains within GSMNP is protected and monitored under
DO #77-2: Floodplain Management (NPS 2003b).
FEMA identifies and maps floodplains as part of the National Flood insurance Program (NFIP). The NFIP
was created to reduce the costs of flood damage to and the potential for future damage to man-made
facilities. Because of the very limited extent of development within GSMNP, neither floodplain limits nor
flood elevations have been determined by FEMA for flood prone areas within GSMNP.
For purposes of this study, approximate methods of flood analyses were used to estimate floodplain
boundaries within GSMNP. General topography in this region is steep, and most stream valleys are confined
Affected Environment — 3-27
North Shore Road Final Environmental Impact Statement

so that the extent of floodplain is limited. Additional detail on FEMA maps is included in the Floodplains
Section of the ECR, Section 3-8. Figure 3-3 illusirates the extent of FEMA mapped floodplains in the study
area.
3.3.3 Hazardous Materials and Underground Storage Tanks
Hazardous material and waste sites are regulated by the Resource Conservation and Recovery Act of 1976
(RCRA), as amended; ihe Comprehensive Environmental Response, Compensation, and Liability Act of
1980 (CERCLA), as amended; and the Superfund Amendments and Reauthorization Act of 1986 (SARA).
Hazardous waste is generally defined as any material that has or, when combined with other materials, will
ha�e a deleterious effect on humans or the natural environment. Characterized as reactive, toxic, infectious,
flammable, explosive, corrosive, or radioactive, hazardous waste may be solid, sludge, liquid, ar gas.
Potential hazardous material and waste sites include service stations, landfills, dumps, pits, lagoons, salvage
yards, and industrial sites, as well as aboveground and underground storage tanks (ASTs and USTs).
Environmental Data Resources, lnc., (EDR) was contracted to search the appropriate federal and state
databases for facilities of potential concern that may be located within the study area. EDR identified 54
sites within the study area. None of these sites were located within GSMNP. More information on the sites
identified by EDR is provided in the Hazardous Material and Waste Sites Section of the ECR, Section 3. ] 3.
Prior to its conversion into GSMNP, the development along what is now the northern shore of Fontana Lake
consisted of residential, commercial, and industrial uses. Although there is no record of registered ASTs or
USTs, it is possible that unregistered ASTs and USTs exist in former inhabited areas within GSMNP.
Furthermore, mining operations were once active at such locations as Hazel Creek and Eagle Creelc. The
presence of hazardous material and waste sites related to these operations as well as the aforementioned land
uses is unknown.
3.3.4 Air Quality
3.3.4.1 Ambient Air Quality Standards
The USEPA, North Carolina Department of Environment and Natural Resources (NCDENR) and some local
level administrative authorities are jointly responsible for protecting air quality within the state. The quality
of air in a given region is managed under the auspices of the Clean Air Act (CAA) by tracking the presence
of certain airborne constituents that are known to have adverse effects on human health and the environment.
These constituents are generally referred to as the "criteria" air pollutants, for which the USEPA has set both
primary and secondary NAAQS. Primary standards represent air qualiry concentrations that are protective of
public health. Secondary standards or "welfare" standards represent air quality concentrations that safeguard
visibility, comfort, animals, and property from the deleterious affects of poor air quality. If the
concentrations of these regulated airborne constituents are measured over a sustained period to be greater
than the NAAQS, the subject region is designated as"non-attainment" for that regulated air pollutant.
Specifically, NAAQS were established for the following air pollutants: carbon monoxide (CO), lead (Pb),
nitrogen dioxide (NOz), sulfur dioxide (SOz), ozone (03), and particulate matter (PM). PM is
Affected Environment — 3-28
North Shore Road Final Environmental Impact Statement

regulated as three groupings, based on particle size. The particle size is measured as the effective
aerodynamic diameter and is the key factor that differentiates particles that affect visibility, from those that
cause stress to the respiratory track, and those that can become trapped within the lungs ar become entrained
into the bloodstream. Under the NAAQS, particulate matter is regulated as PM�o, which are airborne
particles with aerodynamic diameters of 10 microns or less in size; and PM2.5, which are particles with
aerodynamic diameters of 2.5 microns or less.
In addition to the NAAQS, the state of North Carolina has an ambient air quality standard for Total
Suspended Particulate (TSP), which refers to particles with an aerodynamic diameter of 100 microns or less.
Table 3-3lists the NAAQS, including the North Carolina standard far TSP. Also shown are the monitared
values from air qualiry monitoring sites in Bryson Ciry
and in the Park at Purchase Knob, Clingmans Dome,
and Look Rock for various criteria pollutants. Note
that the monitored values may not be representative of
the air quality throughout the entire study area.
Monitars located in the Park indicate that air qualiry
concentrations of regulated air pollutants (primarily 03
and PM2.5), visibility parameters, and atmospheric
deposition rates for nitrogen and sulfur compounds are
USEPA designated the GSMNP portion of Swain declining, especially over the past 5 years. The air
Countv as nnn-attainmPnt fnr n��nP in 2�04_ quality in GSMNP is improving and is expected to
continue to improve in the years to come as a result of
regulatory actions such as the NOX SIP Call, Regional Haze Rule, Non-Road Diesel Engine Rule, the Clean
Air Interstate Rule (CAIR), the TVA's emissions reduction program, the North Carolina Clean Smokestacks
Act, clean fuels program for gasoline and diesel fuels, and future revisions to State Implementation Plan
(SIP) within the region that will address recent non-attainment designations for ozone and PM2.5 discussed in
the next section.
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North Shore Road Final Environmental Impact Statement

Table 3-3. National and North Carolina Ambient Air Quality Standards
Pollutant Type of
Standard
Carbon Monoxide Primary
(CO)
Nitrogen Dioxide Primary and
(NOz) Secondary
Ozone (03) Primary and
Secondary
Total Suspended Primary and
Particulate (TSP) Secondary
Particulate Matter Primary and
(PM 10) Secondary
Particulate Matter Primary and
(PM 2.5) Secondary
Sulfur Dioxide
(SOZ)
Lead
(Pb)
Notes:
Primary
Secondary
Primary and
Secondary
Averaging
Time
8-hour�
1-hour*
Annual
Arithmetic Mean
8-hour^
8-hour
8-hour
8-hour
1-hour
Standard
Value**
9 ppm (10 mg/m3)
35 ppm (40 mg/m3)
0.053 ppm
(100 Ng/m3)
0.08 ppm (157 �g/m3)
0.08 ppm (157 �g/m3)
0.08 ppm (157 �g/m3)
0.08 ppm (157 �g/m3)
0.12 ppm (235 �g/m3)
Annual Geometric 75 ug/m3
Mean
24-hr�
Annual
Arithmetic Mean
24-hour
Annual
Arithmetic Mean
24-hour
Annual
Arithmetic Mean
24-hour
3-hour
Quarterly Average
150 ug/m3
50 �g/m3
150 �g/m3
15 �ag/m3
65 �g/m3
0.030 ppm (80 �g/m3)
0.14 ppm (365 �g/m3)
0.50 ppm (1,300 �g/m3)
1.5 �g/m3
Monitored Location
Value
0.074 ppm
0.085 ppm
0.092 ppm
0.092 ppm
0.091 ppm
21 �g/m3
13.5 �g/m3
100 �g/m3
51.12 �ag/m3
13.4 �g/m3
10.7 Ng/m3
30.9 �g/m3
31.98 ug/m3
Bryson City
Purchase Knob
Clingmans Dome
Look Rock
Bryson City
Bryson City
Look Rock
Bryson Ciry
Look Rock
Bryson City
Look Rock
Bryson City
Look Rock
0.0016 ppm Bryson City
0.008 ppm Bryson City
0.013 ppm Bryson City
* Not to be exceeded more than once per year.
^ To attain the 8-hour standard, the 3-year average of the fourth-highest daily maximum 8-hour average of continuous ambient air
monitoring data over each year must not exceed the standard value. To attain the 1-hour standard, the daily maximum 1-hour
average concentration measured by a continuous ambient air monitor must not exceed the standard value more than once per
year, averaged over 3 consecutive years.
** Parenthetical value is an approximately equivalent concentration. Units of ineasure for the values are parts per million (ppm)
by volume, milligrams per cubic meter of air (mg/m3), and micrograms per cubic meter of air (Ng/m3).
Sources: www.epa.gov/airs/criteria.html USEPA, Air Quality System Quick Look Report 2000, 2001, and 2002
http://vista.cira.colostate.edu/views; NPS Monitors AQS#:37-087-0036; AQS#:47-155-0102; AQS#:47-009-0101
3.3.4.2 Non-Attainment Designations
USEPA designates an area as "attainment" if monitoring data indicate that the ambient concentrations of the
criteria pollutants meet or are below the NAAQS. A designation of "non-attainment" is given for areas that
exceed or "violate" the standard, or have contributed to violations of the NAAQS. There are several levels
Affected Environment — 3-30
North Shore Road Final Environmental Impact Statement

of attainment (basic, marginal, moderate, serious, severe, or extreme) based on the severity of the violating
conditions.
On April 15, 2004, the USEPA made final non-attainment designations of the 8-hour ozone standard
nationwide, designating the GSMNP as "basic non-attainment," including only the parts of both Swain and
Haywood counties in the Park. This partial two-counry area is known as the "Great Smoky Mountains
National Park non-attainment area." 'Che Park counties on the Tennesse�side of the Park are part of the
seven-counry Knoxville non-attainment area. These designations indicate that air quality within the Park
meets the 1-hour ozone standard, but does not meet the 8-hour standard. As a result of this designation and
other non-attainment area designations made across the state, NCDENR must take action toward improving
air quality to attain ihe new 8-hour ozone standard by the federally mandated deadlines established by the
1990 Clean Air Act Amendments (CAAA). This requires a revision to the STP that establishes emission
control requirements and permitting requirements far various sources of air pollution that contribute to the
ozone violation.
At this time, NCDENR is in the process of revising its SIP. The proposed SIP must be submitted by April
2007. Concurrently, the USEPA has been taking a wide range of national clean air actions that will help all
areas across the country significantly improve ozone air qualiry. Ozone is not directly emitted to the
atmosphere from air emission sources, but is a pollutant that fonns as a result of the atmospheric reactions of
nitrogen oxides (NOx) with volatile organic compounds (VOC) in the presence of sunlight. Ozone levels
tend to be higher during the warmer months between May through September. Therefore, the USEPA's
actions for reducing ozone concentrations are implemented by reducing emissions of NOx from various
emission source types. Note tbat in certain farested areas, especially GSMNP, VOCs are produced and
emitted to the atmosphere by natural biological processes that cannot be controlled. For these areas
especially, ozone is most effectively controlled by reducing concentrations of NOx.
Many of these federal clean air actions are expected to bring local areas into attainment without any
additional local controls. These national clean air control programs include:
■ USEPA's regional ozone transport rule (known as the NOX SIP Call),
■ USEPA's Clean Air Interstate Rule which addresses issues of pollution transported across state
boundaries,
■ Clean Air Diesel Rules targeting diesel emissions from on road and off road diesel engines, and
■ USEPA is also phasing in very stringent tailpipe standards for cars, trucks, and SLJVs that also reduce
NOX emissions.
While these actions are being implemented, in the interim, non-attainment areas must demonstrate that they
are making reasonable further progress toward improving their air quality.
Transportation conformity and associated requirements were introduced in the CAA of 1977 and made more
rigorous in the CAAA of ] 990. A transportation conformity regulation was issued in November, 1993
detailing implementation of the ] 990 requirements. "Transportation conformiry is a way to ensure that
Federal funding and approval goes to those transportation activities that are consistent with air qualiry goals,"
Affected Environment — 3-31
North Shore Road Final Environmental Impact Statement

and applies to approval or funding by FHWA of projects in non-attainment areas (NCDOT 2004). As
described previously, the project is located in an ozone non-attainment area. As discussed in Section 5. ] 0,
NPS and FHWA have coordinated with NCDOT and the North Carolina Division of Air Qualiry (NCDAQ)
regarding conformiry requirements that could apply to the North Shore Road Project. The North Shore Road
project has been included in the NCDOT 2007-2013 State Transportation Improvement Program (STIP) as
project R-4908 for planning and environmental study only (NCDOT 2007). NCDOT issued a draft report
titled Transportation Conformity Analysis for the North Shore Road in the Great Smoky Mountains National
Park (Haywood and Swain Counties) in December 2006 (NCDOT 2006).
3.3.4.3 The Clean Air Act and Class 1 Areas
The CAA passed in 1970 established national policy to preserve, protect, and enhance air quality. The 1977
CAAA established the Prevention of Significant Deterioration (PSD) rules and defined Class I areas. All
national parks that exceed 6,000 ac (2,428 ha) in size, as of 1977, are designated Class I areas, including
GSMNP. Class I areas are afforded the greatest degree of air qualiry protection under the Act. PSD
increment concentrations were established for sulfur dioxide, particulate matter, and nitrogen dioxide within
the Class I areas. New or expanding major facilities that will potentially affect the air qualiry of a Class I
area must prove that they will not add emissions that will cause ambient concentrations in Class I areas to
increase above the allowable PSD increment values. In addition, Federal land managers (FLMs) have the
responsibiliry to protect the quality of air in Class I areas. FLMs are to take an active role and err on the side
of protection when making decisions on air quality. Reviewing permits and projects for new and expanding
major sources of air pollution is part of their responsibility. This review process allows the FLMs the
opportuniry to serve in an advisory role and to comment on whether tbese new sources of pollution will
adversely affect the air quality of nearby Class I areas.
Protecting the air quality of Class I areas, specifically GSMNP, is difficult because most of the air pollutants
threatening the Park, are emitted outside the Park. Due to prevailing air currents and the terrain of the
region, pollutants from urban and indusirial areas in the Tennessee, Ohio, and Mississippi river valleys are
trapped and concentrated in the southern Appalachians. In addition, pollutants from elsewhere in the
Northeast, Southeast, and Midwest threaten the air quality of the region.
Sulfur dioxide and nitrogen oxides, emitted from the burning of fossil fuels, are responsible for the majority
of air quality impacts at GSMNP. These emissions convert to harmful secondary pollutants (e.g., sulfate,
nitrates, particulate matter, and ozone). Ozone pollution is responsible far harming human health and
damaging vegetation. High levels of ozone can irritate the respiratory track and lungs of Park visitors and
employees. The effects of elevated ozone concentrations on vegetation can range from foliar injury and
premature leaf loss to reduced photosynthesis and reduced growth in sensitive plant species. The impacts of
existing ozone on vegetation are discussed in Vegetation Communities, Section 3.4.5. One metric used far
evaluating potential biological effects of ozone exposure is the SUM06 statistic, which is the sum of hourly
average ozone concentrations greater than or equal to 0.06 ppm calculated over a 3-month period. Generally,
a SUM06 value of less than or equal to 8 ppm-hrs is considered to be protective against foliar injury and
growth loss. The SUM06 ozone exposures recorded in GSMNP at Look Rock and Clingmans Dome over a
5-year period between 2000 and 2004 are 31 ppm-hrs and 34 ppm-hrs, respectively.
Affected Environment — 3-32
North Shore Road Final Environmental Impact Statement

In addition to the formation of ozone, air pollution results in deposition of airborne sulfur and nitrogen
compounds under both wet and dry weather conditions. Nitrogen and sulfur deposition phenomena is
adversely affecting streams and soils in the higher elevation spruc�fir forests of the Park and is well
documented in the Park's Noland Divide Watershed in Swain County. In fact, Noland Divide receives some
of the highest rates of nitrogen and sulfur deposition compared to any other monitored location in North
America. Research shows that certain high elevation forests are receiving so much airborne nitrogen tbat
they are suffering from advanced stages of nitrogen saturation. This condition limits the availability of forest
nutrients, especially calcium, to plants and animals, and causes the release of toxic aluminum that can harm
vegetation and stream-life. The degradation of these resources is impacting aquatic as well as terrestrial
resources. Mountain streams and forest soils are being acidified to the point that the health of the Park's high
elevation ecosystems are in jeopardy. The impacts of current deposition and acidified soil conditions on
Park water quality and vegetation are discussed in Section 3.43 and Section 3.4.5, respectively.
Monitoring of both wet and dry weather deposition rates is ongoing in GSMNP. in 1990, USEPA
established the Clean Air Status and Trends Network (CASTNet) as a nationwide network of monitoring
stations that collect actual deposition samples of sulfur and nitrogen particles and gases during dry
conditions. CASTNet operates a deposition monitor at Look Rock, Tennessee. At the same time, the
National Atmospheric Deposition Program (NADP), which is a collaborative effort between multiple
government and state agencies, operates a network of monitors measuring wet deposition rates across the
country, including a monitor in GSMNP at Elkmont, Tennessee. Existing deposition rates calculated from
data obtained from the CASTNet and NADP monitoring sites indicate that the average annual deposition rate
for total sulfur between 2000-03 is 8.95 kg/ha/yr. During the same period, an annual average total nitrogen
deposition rate of 8.52 kg/haJyr was measured.
Poor air quality also jeopardizes visitor enjoyment of the Park by reducing visibility. Visibility at GSMNP
has been greatly degraded due to air pollution during the last 50 years. The annual average visual range at
scenic views is currently 25 mi (40.2 km), when historically it was over 110 mi (] 77 km). Most of the
Park's haze comes from particulate matter made up of a mixture of chemical, primarily sulfate, particles
which scatter and degrade visibility. Recent visitor surveys have shown that visitors to the Park said that
clean air was extremely important to them during their stay in the Park, and that 84 percent said that scenic
views were extremely important. Viewing scenery is the number one activiry reported by Park visitors
(NPS 2002b).
Under the Clean Air Act Regional Haze Program, visual air quality in ] 56 Class I areas across the country is
being monitored. Visual quality is measured in terms of the 20 percent clearest (best) days and the 20
percent haziest (worst) days over a 5-year period. The ultimate goal of the Regional Haze Program is to
restore visual clariry to the level defined as the "natural visibiliry conditions" for the 20 percent haziest days
and prevent visibility on the 20 percent best days from getting worse. Natural visibility conditions represent
the long-term degree of visibility that is estimated to exist in the absence of human-caused effects.
Visibility conditions, progress goals, and changes in natural visibility conditions are expressed in tenns of
deciview (dv) units, per 40 CFR 51.308(d)(1). The deciview is a unit of ineasurement of haze that indicates
changes in perception of haziness (derived from light extinction). The approved methodology for calculating
visibiliry in Federal Class I areas was established by the Interagency Monitoring of Protected Visual
Affected Environment — 3-33
North Shore Road Final Environmental Impact Statement

Environments (IMPROVE). Concentrations of particulate matter species are summed in conjunction with
the relative humidity averages for a given area. The values collected by the IMPROVE monitor located at
Look Rock indicate approximate 5-year (2000-2004) averages of 29.1 dv representing the 20 percent worst
days and 13.9 dv representing the 20 percent best days. The default natural visibiliry parameters for all
mandatory federal Class I areas are provided in USEPA's Guidance for Estimating Natural Visibility
Conditions Under the Regional Haze Rule (USEPA 2003a). Default natural visibility values for GSMNP are
3.76 dv and 1].44 dv for the best and worst days, respectively.
3.3.4.4 Air Toxics
Under the CAAA of 1990, the USEPA significantly expanded its list of toxic air pollutants. Toxic air
pollutants, also known as hazardous air pollutants (HAP), are those pollutants that are known or suspected to
cause cancer or other serious health effects, such as reproductive effects or birth defects, or adverse
environmental effects. USEPA is working with state, local, and tribal governments to reduce air toxics
releases of 188 polhrtants to the environment. Examples of toxic air pollutants include benzene, which is
found in gasoline; perchlorethlyene, wbich is emitted from some dry cleaning facilities; and methylene
chloride, which is used as a solvent and paint stripper by a number of industries. Examples of other listed air
toxics include dioxin, asbestos, toluene, and metals such as cadmium, mercury, chromium, and lead
compounds.
USEPA monitors ambient air concentrations of some HAP compounds under the Urban Air Toxics
Monitoring Program (UATMP), which is a program that is designed to characterize the magnitude and
composition of potentially toxic air pollution in, or near, urban locations. The UATMP includes 53
monitoring stations, including one located in Kingsport, Tennessee, and one in Loudon, Tennessee
(southwest of Knoxville). The most recent data available from these monitors show that benzene and
acetaldehyde are the most prevalent HAP compounds detected, as provided in 2003 Urban Air Toxics
Monitoring Program July 2004 Final Report (USEPA 2004a). Ambient concentrations of HAP vary widely
throughout the UATMP network since many of the HAP compounds originate from a variety of industrial,
motor vehicle, and natural emission sources.
The Park and TVA are currently monitoring mercury deposition at Clingmans Dome and Elkmont as part of
the Mercury Deposition Network (MDN). Monitaring results from 2002-2004 show that deposition of total
mercury at the Park is in the top 10 percent of the national network. The Clean Air Mercury Rule should
help to reduce mercury deposition at the Park. To reduce HAP nationwide, the USEPA has promulgated
National Emission Standards for Hazardous Air Pollutants (NESHAP) that are aimed at reducing emissions
of HAP at specific industrial processes that are known to emit significant quantities of HAP compounds.
Some examples of affected processes are industrial boilers, organic chemical manufacturers, refineries, and
pulp and paper manufacturers. The NESHAP are technology-based standards that require emission sources
to implement Maximum Achievable Control Technology (MACT) to reduce HAP emissions. Many HAP
emission sources affected by these new rules are currently in the process of installing MACT. For GSMNP,
and other regions across the nation, concentrations of HAP are continuing to be reduced through the
implementation of the new NESHAP rules.
Affected Environment — 3-34
North Shore Road Final Environmental Impact Statement

3.3.5 Soundscapes
Sounds from wind, moving water, and wildlife dominate the soundscape of the study corridars. The existing
soundscape and ambient sound levels in the study area are briefly summarized in this section and are detailed
in the Noise Section of the ECR, Section 3.12. The goal to preserve, maintain or restore the natural
soundscape, is an NPS policy (NPS 2006). Human-caused sound from such sources as traffic or motorized
equipment can degrade the natural soundscape. As noted in Solitude Impacts, Section 4.2.5.2.9, the existing
GSMNP soundscape north of Fontana Lake provides serenity and a sense of solitude to visitors.
Examples of sound levels related to human perception, in an A-weighted decibel level (dBA), are listed in
Table 3-4. These are provided for context only. Uarious levels of sound and how they are perceived to fall
within a continuum of very quiet to loud are highly dependent upon type of environment in which they are
experienced. Perceptions of "loudness" or annoyance, for example, may be very different between an urban
environment and a national park environment. Decibel level is not the only determinant of annoyance. The
frequency, or tone, of sound may also be perceived as out of character for a given setting, especially when
people expect "quieY' or to hear only natural sounds. Some sounds may be deemed as annoying regardless
of their decibel level.
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North Shore Road Final Environmental Impact Statement

Table 3-4. Typical Human Hearing Levels
A-weighted decibel levels
140 Shotgun blast,
jet 100 ft(30 m) away at takeoff
130
Firecrackers
120 Severe thunder, pneumatic jackhammer
Hockey crowd
Amplified rock music
110
100 Subway train, elevated train, farm tractor
Power lawn mower, newspaper press
Heavy city traffic, noisy factory
.�
Diesel truck 40 mph (65 kph), 50 ft(15 m) away
80 Crowded restaurant, garbage disposal
Average factory, vacuum cleaner
Passenger car 50 mph (80 kph), 50 ft(15 m) away
70
Quiet typewriter
60 Singing birds, window air conditioner
Quiet automobile
Normal conversation, average office
50
Quiet office
40
Average home
30 Dripping faucet
Whisper 5 ft(1.5 m) away
20 Light rainfall, rustle of leaves
Whisper
10
0
Painfully loud
Human ear pain threshold
Uncomfortably loud
Loud
Moderately loud
Quiet
Very quiet
Average person's threshold
of hearing
Just audible
rhreshold tor acute hearf
Source: World Book, Rand McNally Atlas of the Human Body, Encyclopedia Americana, "Industrial Noise and Hearing
Conversation" by J. B. Olishifski and E. R. Harford (Researched by N. Jane Hunt and published in the Chicago
Tribune in an illustrated graphic by Tom Heinz). Original table title, "Hearing: Sounds that Bombard Us Daily."
Ambient3 sound level measurements taken in 2003 are shown on Figure 3-4, which help to quantify the
existing acoustic environment and provide a basis for assessing potential future impacts, which are discussed
in Chapter 4. Differences in the measured sound levels are attributed to variations in site conditions and
traffic volumes. The sound level distribution for the study area ranges from 35 dBA to 79 dBA. The higher
range values occur on NC 28 in the vicinity of existing road construction. Lower-range values occur in and
close to GSMNP. Sound readings north of Fontana Lake were approximately 43.3 dBA, as detailed in the
Noise Section of the ECR, Section 3.12.
3 Ambient level refers to the total sound environment combining all natural sounds with all human caused sounds, including traffic,
overflights and other sound sources.
Affected Environment — 3-36
North Shore Road Final Environmental Impact Statement