20080540 Ver 1_EA Comments_20080402

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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION 4
i = ATLANTA FEDERAL CENTER
° 61 FORSYTH STREET
?111` pnoltcl ATLANTA GEORGIA 30303-8960
April 2, 2008
Ms Jennifer H Hams, P E , Staff Engineer
North Carolina Turnpike Authority
1578 Mail Service Center
Raleigh, North Carolina 27699-1578
SUBJECT EPA Review Comments of the Federal Environmental Assessment for
U-476313, Triangle Parkway, from NC 540 to I-40, Wake and Durham
Counties
Dear Ms Hams
The U S Environmental Protection Agency Region 4 (EPA) has reviewed the
subject document and is commenting in accordance with Section 309 of the Clean Air
Act and Section 102(2)(0) of the National Environmental Policy Act (NEPA) The
North Carolina Turnpike Authority (NCTA) and the Federal Highway Administration
(FHWA) are proposing to construct a 3 4-mile new location, multi-lane toll facility
between NC 540 and I-40 in the Research Triangle Park (RTP) area of Wake and
Durham Counties In addition, the proposed project would also entail the widening of
eastbound NC 540 for 1 3 miles and the widening of northbound NC 147 for 1 9 miles
The primary signatory agencies to the Section 404/NEPA Merger 01 process,
including the U S Army Corps of Engineers (ACE), the North Carolina Division of
Water Quality (DWQ), the North Carolina Department of Transportation (NCDOT) and
FHWA agreed with the NCTA not to include this proposed toll project in the full Merger
01 process An ACE Section 404 Individual Permit (IP) appeared likely based upon 2006
estimated jurisdictional wetland and stream impacts NCTA has been advancing this
proposed project under the SAFETEA-LU Section 6002 environmental coordination
process (i e, Turnpike Environmental Agency Coordination - TEAC process) It should
be noted that several representatives from NCDWQ requested that NCTA include this
project in the NCDOT's Merger Process (Triangle Parkway Agency Scoping Meeting,
1/25/06, Appendix D)
NCTA held a TEAC meeting on Triangle Parkway on October 17, 2007 Under
the meeting minutes, NCTA stated that "agencies will provide written comments on
avoidance and minimization measures by November 9, 2007" Agencies were further
instructed by NCTA to provide written comments on the findings and conclusions of the
Qualitative Indirect and Cumulative Effects assessment by November 9, 2007 NCTA
provided the ACE and NCDWQ with copies of the draft hearing maps to assist them in
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their review of the avoidance and rmnimmization efforts NCTA, with NCDOT assistance,
held a"Concurrence Point 4B-Hydraulic RevieW'type meeting with State and Federal
agencies on November 14, 2007 NCTA, with NCDOT assistance, held a`Concurrence
Point 4C-Permit RevieW'type meeting on December 5, 2007 EPA also acknowledges
that the ACE has issued the Public Notice on March 21, 2008, for the Section 404 perrrut
for the Triangle Parkway project
The scoping comments reflected in the January 25, 2006, meeting minutes do not
specifically address the reasons for preparing an EA for the proposed project According
to FHWA regulations at 23 CFR Section 771 115(a)(1) and (2), an Environmental Impact
Statement (EIS) is normally required for a new controlled access facility and a highway
project of four or more lanes on new location The scope of the Triangle Parkway met
both conditions for preparing an EIS There are other statements in NCTA meeting
minutes that an EA will be prepared for the proposed project without a specific
discussion as to why this new location project did not require an EIS
EPA has environmental concerns regarding impacts to streams and wetlands, a
Significant Natural Heritage Area, noise receptors, and air quality EPA is requesting
additional information on the air quality analysis performed, including the 8-hour Ozone
standard and Mobile Source Air Toxics (MSATs) EPA requests that these issues be
fully addressed before a final NEPA document is issued for this project and that copies of
appropriate information and repo -are provided to me with a copy to Mr Christopher
Militscher of my staff EPA's EA review comments are contained in Attachment 1
Because of the potential issues involving MSATs and the inclusion of a quantitative
assessment, EPA is providing detailed technical air toxic mobile comments on the EA in
Attachment 2 These comments also should be addressed prior to the issuance of a final
NEPA document
Because there are deficiencies in the EA and unresolved issues concerning the
proposed design and water and air quality impacts, EPA recommends that FHWA and
NCTA_consider an EA Re-evaluation to address outstanding concerns EPA is also
seeking greater consideration of avoidance and minimization efforts as well as utilizing
very stringent Best Management Practices (BMPs) during construction Thank you for
the opportunity to comment
Sincerely,
Heinz J Mueller, Chief
EPA Region 4 NEPA Program Office
Attachments 1 and 2
cc Gregory Thorpe, NCDOT
John Sullivan, FHWA
Brian Wrenn, NCDWQ
Scott McClendon, USACE
Attachmentl - - - - - - -- --
Triangle Parkway U-4763B
Wake and Durham Counties
EPA Review Comments on the Environmental Assessment
April 2, 2008
RTP Master Plan
The EA references the RTP Master Plan in numerous sections and is included as
Figure I-2 The original plan was developed in 1958 and the current version shown in the
EA is dated January 2006 There are light green areas shown on this figure with no
description in the legend The proposed Triangle Parkway corridor follows this green
shaded area throughout most of the park The RTP Master Plan includes a'Hollow Creele
between lots 49 and 50 There is no description of Hollow Creek in the EA
While there appear to be some designated `Natural Area Preserves' in the southern
potion of the RTP Campus within Wake County there are no preserves or conservation
areas shown north of the county line into Durham More than two-thirds of RTP is
within Durham County All of the lots depicted are either sold, under option, available for
sale, designated service centers or park research centers There are no designated
`gneenspaceg in Durham County Significant Natural Heritage Areas (SNHAs) as
designated by the North Carolina Natural Heritage Program (NCNHP) are not shown on
the RTP Master Plan The proposed Hopson Road Interchange will impact 3 4 acres of
the SNHA Site ID #2527
EPA cannot ascertain if any specific environmental features were included in the
development of the RTP Master Plan NCTA and FHWA have greatly relied on this plan
for the development of new location preliminary alternatives From this plan and other
maps contained in the EA, it appears that the proposed corridor follows the terminus for
NC 147 at T W Alexander Drive through the center of the park until it is proposed to
connect to Hopson Road EPA is concerned that most upland areas within RTP were
Yeserved for development purposes and infrastructure such as new roadways and utilities
were planned for `low-lying areas Pages 5-8 and 5-9 of the EA itemize the 15 utility
entities that have infrastructure within the project study area and are anticipated to require
utility relocations There are also several privately owned water/sewer systems and
communication facilities that could also be impacted by the proposed project
Traffic Analysts and Alternatives
Section 2 1 of the EA discusses traffic congestion impacts While most of this
information is correct and supported by existing studies, EPA notes that traffic safety can
be confusing when congestion is relieved through the construction of new high-speed
roadways Based upon recent FHWA studies, new high-speed facilities may not decrease
the number of accidents Furthermore, new high-speed facilities can possibly increase
the seventy of traffic accidents as well
The EA also states that congestion contributes to environmental damage of air and
water quality from concentrated emission levels Air quality is certainly expected to
improve with reduced traffic congestion assuming that the new facility is not inducing
additional traffic and vehicle miles traveled in the project study area However, there is
no direct link between reduced traffic congestion and improved water quality (due to
concentrated emission levels) Water quality is expected to be degraded in the project
study area following the construction of the new roadway due to increased impervious
surfaces, more runoff from contaminants, reduced riparian buffers and vegetation, etc
EPA is concerned with the lack of a comprehensive traffic plan for the project
study area that does not include the`2-40 High Occupancy Vehicle (HOV) Lane
Altemativd'(Section 2 2 3 of the EA) as part of the final NEPA decision for the proposed
project There are numerous benefits cited in the EA for I-40 HOV lanes and that this
alternative would compliment the proposed Triangle Parkway While EPA understands
that this Alternative does not specifically eliminate the need for the proposed Triangle
Parkway, FHWA and NCDOT should have included a discussion on when this
Alternative might be incorporated into the overall comprehensive transportation plans for
the project study area The I-40 HOV Alternative is a distinct alternative and serves the
east-west movement of traffic through RTP The final report was published in March of
2003 (i e , I-40 HOV/Congestion Management Study) and the focus was on I-40 because
`k is the Triangle region's most important transportation artery' Since the issuance of the
final report, there has been no specific transportation project that incorporates the final
reporfs recommendations and conclusions for HOV lanes
The EA addresses the potential alternative of converting an existing roadway
(e g, Davis Drive, NC 54 or NC 55) to a fully-access controlled freeway There is a
general assessment that the conversion of some of the existing roadways would not meet
the purpose and need for the project However, the conversion of Davis Drive"could
meet the purpose of improving access to RTP, although it would close existing driveway
access and displace several of the large employers in RTP' While tlus widening
alternative would obviously have substantial impacts to some of the large businesses
within RTP (e g , Biogen, Sony Ericsson and Cisco), impacts to natural resources such as
streams and terrestrial forests would potentially be substantially less Davis Drive
parallels the new Triangle Parkway throughout most of the project study area There
could also be traffic management issues associated with the intersection of Davis Drive
and Cornwallis Road From a NEPA analysis standpoint, it would have been beneficial
for the public, resource agencies and decision-makers to evaluate this potential Davis
Drive Widening to a Freeway Alternative in more detail in order to make a full
comparison of the impacts to a new location freeway It is important to note that Davis
Drive is being widened to a four-lane, median divided facility under TIP# U-4026 to
increase traffic carrying capacity, improve mobility, to manage congestion and to
improve safety (February 2002 NCDOT Newsletter, Issue #2) This 5 3-mile project is
depicted on Figure 1-4 of the EA and is currently under construction Acquisition of
additional right of way was required for this estimated $18 million project and impacts to
Burdens Creek and Kit Creek and their tributaries resulted from this project EPA
recognizes that driveway access along. the-existing Davis Dnve route would be also an
issue The lack of `economic feasibility is an additional factor that supported NCTA and
FHWA's decision to eliminate this widening alternative from further consideration (Page
2-8 of the EA) However, EPA also notes that the Davis Drive Widening to a Freeway
Alternative was not evaluated in conjunction with any Mass Transportation alternatives
or Traffic System Management (TSM) options
EPA is concerned that the `HCS traffic analysis tool that is typically utilized for
most projects indicted that most of the major roadway facilities are expected to operate
over capacity with or without the construction of Triangle Parkway by the 2030 design
year (Page 2-16 of the EA) The microsimulation (CORSIM) analysis was also utilized
for future traffic conditions and that it considers all locations simultaneously on a
network basis EPA recognizes that volume to capacity (V/C) ratios are improved with
the proposed project (Table 2-5 of the EA) However, EPA is concerned that based upon
the addition network analysis, there are several future project considerations that will be
need to be made at future dates but within the 2030 design year This includes the
widening of eastbound NC 540 and the widening of the flyover from eastbound NC 540
to northbound Triangle Parkway by 2024 and the widening of Triangle Parkway from 6-
lanes to 8-lanes until after the McCnmmon Connector (TIP #U-4763A) is constructed
The widening of Triangle Parkway between NC 540 and I-40 is proposed to be evaluated
as part of that project Furthermore, I-40 was determined to need widening in the future
with or without the addition of the Triangle Parkway There are no studies or designs in
place to widen I-40 (Page 2-20 of the EA)
It is noted that several local planning organizations show the Triangle Parkway as
either a four-lane road with a landscaped median or a four-lane expressway (i e , Town of
Cary Thoroughfare Plan and North Morrisville-Shiloh Small Area Plan, respectively)
Wake Countys Transportation Plan shows NC 540 but does not show Triangle Parkway
Relocations
The EA indicates that there will be 2 residences and 0 businesses directly
impacted by the proposed new location facility. EPA performed a comparison between a
3 4-mile new location project and the Merger baseline for the same environmental
indicator based upon impacts per mile For atypical Eastern North Carolina project,
there are on average 3 1 residential and 4 0 business relocations per mile for new 4-lane
project EPA recognizes that the project study area is mostly contained with the Research
Triangle Park planning area and that residential units are not permitted in the park and the
proposed toll facility is 6-lanes (instead of 4-lanes used in the baseline analysis)
Noise Receptors
According to the EA there are anticipated to be 13 residential noise receptors
impacted, 1 recreational facility impacted and 2 businesses impacted These project noise
impacts are anticipated without abatement measures EPA recognizes that further noise
studies may be required for the remaining phases of Kitts Creek and Davis Park
developments, The EA discusses-noise barriers at several locations (t e, Barrier B, C, E
and I) Based upon the NCDOT Traffic Noise Abatement Policy and the determination
of reasonableness and feasibility, NCTA proposes one noise barrier at Barrier E with a
preliminary size of 10 feet in height and 1,651 feet long EPA concurs with the
recommendation for a noise barrier at this location EPA made a comparison of noise
receptor impacts per mile to the baseline for both Eastern and Western NC new location
projects and found that the proposed project is below the average for both (i e , Eastern
new location = 8 9 impacted receptors/mile and Western new location = 5 2 impacted
receptors/mile) Using 3 4 miles and a total of 16 impacted noise receptors, the Triangle
Parkway potentially impacts (without abatement measures) 4 7 receptors/mile With the
proposed noise barrier at the Barrier E location, the proposed project will have less than
the average 4 7 impacted receptors per mile
Other Human Resources Impacts
EPA recognizes that there are no identified impacts from the proposed Triangle
Parkway to National Historic Preservation Act (NHPA) eligible or listed historic
properties, Section 4(f) properties, archaeological sites, prime farmlands, churches or
schools, cemeteries and other typical community facilities
Wetland and Stream Impacts
The EA (Table 5-4) states proposed impacts to streams and wetlands as follows
4,647 linear feet of perennial stream, 4,082 linear feet of interimttent stream, and 2 05
acres of wetlands The primary streams that will be impacted by the proposed project
include Burdens Creek and Kit Creek and associated unnamed tributaries (UTs) These
streams are part of the Cape Fear River Basin Both Burdens Creek and Kit Creek and
their associated UTs are classified by NCDWQ as Class_C-NSW (Nutrient Sensitive
Waters) The class"C'designation denotes fresh waters protected for secondary
recreation, fishing, wildlife, fish and aquatic propagation and survival and other uses
The NSW classification notes that additional nutrient management for these waters is
needed because they are subject to excessive growth or microscopic or macroscopic
vegetation Both Burdens Creek and Kit Creek drain to Northeast Creek which from NC
55 to the New Hope Creek arm of Jordan Lake is currently on the Section 303(d) list of
impaired waters Northeast Creek is listed as impaired due to fecal coliform, turbidity,
low dissolved oxygen and impaired biological function Based upon EPA's review of the
project files for U-4026, David Drive Widening, more than 1,050 linear feet of impact to
tP Burdens Creek and Kit Creek and their tributaries will result from this ongoing project
The proposed Triangle Parkway will result in an additional 8,000 linear feet of stream
impact and approximately 2 acres of wetland impact to this system Northeast Creek
could be further impaired from impacts to both Burdens Creek and Kit Creek and their
tributaries
EPA has performed a comparison analysis to a baseline for other new location
projects in Eastern North Carolina Using solely perennial stream impacts of 4,647 miles
for a 3 4-mile new location facility, the `per miles impact to streams is 1,366 7 linear feet
per mile The Merger baseline for Eastern North Carolina new locations projects is 473 0
linear feet per mile Even using a Western North Carolina new location project of 907 1
linear feet per mile of stream impacts, the proposed toll facility is still well above the
average per mile impact
EPA also notes that the November 27, 2007, preliminary design drawings
prepared by Mulkey Engineers and Consultants show a Hollow Creep along the eastern
portion of the new toll road The cover sheet to the preliminary design plans Sheets 9, 10
and l Iindicate this named stream The individual plan sheets only indicate a creek The
EA does not describe a Hollow Creek' This issue should be clarified to EPA and other
agencies before a final NEPA decision is made for this project
Avoidance and Minimization Measures
The EA states that bridging is proposed in the functional designs for Burdens
Creek in the northern part of the project study area The EA identifies that the Preferred
Alternative incorporates a split-diamond interchange at David Drive and Hopson Road
that minimizes stream and wetland impacts Additionally, the proposed retaining wall
along the EPA RTP property line minimizes impacts to the ITTs to Burdens Creek
(`Hollow Creek' as shown on several plans) The EA further states that additional
minimization could be achieved through the use of bottomless culverts and steeper side
slopes, where feasible Based upon the Triassic soils and the lack of stream bedrock
materials in the project study area, it is unlikely that bottomless culverts are feasible
Furthermore, the statement that steeper side slopes are a possible nummization measure
is inconsistent with the statement on Page 5 of 14 from the NCTA's October 17, 2007,
meeting minutes (Based on the geotechnical recommendations for this area, the ability to
use steeper side slopes is limited Due to poor soil conditions in the project study area,
the geotechnical recommendations for the project specified four to one (4 1) of flatter
side slopes in areas with cut heights in excess of 10 feet to ensure slope stability ")
The TEAC meeting minutes from October 17'' also differs in the total wetland
and stream impacts described in the EA (i e , 1917 acres of wetlands, 3,993 linear feet of
perennial streams, and 3,876 linear feet of intermittent streams) The Section 5 of the EA
also lacks the specificity of the avoidance and minimization measures included in the
meeting minutes According to the preliminary designs, the retaining wall along the EPA
property will reduce wetland impacts by approximately 0 57 acres and stream impacts by
2,450 linear feet The interchange design at Hopson Road/Davis Drive will reduce
stream impacts by an estimated 198 linear feet The proposed bridge over Burdens Creek
reduces wetland impacts by approximately 0 22 acres A retaining wall at the NC 540
ramp toll plaza reduces stream impacts by approximately 600 linear feet These specific
items are included in Section 3 of the EA for the Preferred Alternative but are left out of
Section 5 on the Environmental Consequences
EPA recommends that these specific avoidance and minimization measures be
included in the final NEPA document Furthermore, NCTA and FHWA should analysis
the differences in the stream and wetland impacts from the October 17, 2007, TEAC
meeting minutes, the ACE Public Notice and the EA and provide a detailed explanation
for any differences
Section 3 16 of the EA states that the planning measures included in selecting the
project corridor location that collectively avoids and rrunimizes impacts to resources
within the project area Furthermore, the EA states that the alignment for the Preferred
Alternative was designed to avoid impacts to the EPA and Keystone properties and to
avoid the relocation of the office building located on 4105 Hopson Road The NCTA and
FHWA only examined one other Build Alternative alignment (Table 2-1 Preliminary
Corridor Evaluation Green and Yellow Corridors) The EA does not provide what
specific planning measures that were included in selecting the project corridor that
collectively avoids and minimizes impacts to resources The"Yellow'or Corridor B
Alternative was infeasible from the onset of project planning due to the inability to
condemn Federal lands and was also inconsistent with the RTP Master Plan From
earlier scoping meeting discussions, the proposed project has been presented to EPA and
other agencies as a'One build alternative' project once NCTA learned that EPA and/or
NIEHS were not willing to sell property at RTP EPA does not believe that NCTA and
FHWA can support the statement claimed in Section 34 6 concerning early planning
avoidance and minimization Based upon impacts to,-J-rennial and intermittent streams
of more than 8,600 linear feet, 2 acres of wetlands and 12 6 acres of floodplains, the
location of this new roadway has been potentially 1steered to low-lying areas within RTP
EPA believes that further consideration o oidance and minimization measures
to streams needs to be considered, including the use of additional retaining walls and the
y / reduction in either the median or shoulder widths Figure 3-1 of the EA includes the
proposed typical section of the Triangle Parkway mainline The 46-foot total median
includes two 12-foot interior paved shoulders, six (6) 12-foot travel lanes, two 12-foot
exterior paved shoulders and 6 1 to 2 1 variable side slopes In effect, there are 10 lanes
of pavement covering approximately 112 feet of impervious surface with approximately
26 feet of unpaved, grass median The total construction width is estimated at
approximately 250 feet According to NCTA's analysis performed in October and
November of 2007, slopes less than 4 1 (steeper) are not generally feasible due to the
type of soils in the project study area EPA recognizes that retaining walls are already
proposed at six separate locations (Section 3 10 2) However, EPA recommends that
NCTA consider additional retaining walls at selected impact locations, reduce the interior
c _- 10-foot paved lanes, and make ever effort to minimize the 250-foot construction width
One of the most substantial impact areas to streams and wetlands is the location
between the Davis Drive Interchange and the Hopson Road Interchange where Sites 6, 8,
9 and 10 are located The largest wetland impact for the project occurs at this location as
well as more 500 linear feet of stream impact EPA requests that other interchange
designs options be considered for this interchange (i e , Service Ramps-SR land SR 2) to
reduce wetland and stream impacts Connecting the `western loope of the Hopson Road
Interchange with the `eastern loopg of the Davis Drive Interchange with SR 1 and SR 2
appears to create a much larger construction footprint than if each interchange were
individually designed and connected to Triangle Parkway If spacing between
interchanges is an issue, NCTA? should consider eliminating one of the interchanges
(Davis Drive) There is an existing multiple lane intersection with Davis Drive and
Hopson Road a quarter of a mile east of the proposed Triangle Parkway interchange at
Hopson Road
kp
The EA does not describe in detail the potential impacts from relocation of
numerous utilities within the project construction footprint Based upon the general
discussion in the Ed, impacts to natural resources could be substantial from utility
relocations NCTA should consider further examination of these potential impacts
Potential disruptions in vital utility services also need to be closely coordinated with
businesses and Government agencies within RTP
Best Management Practices (BMPs)
Due to the potential impacts to NSW streams from the proposed project and other
® sensitive resources in the project study area, EPA recommends that the most stringent
BMPs be included in the design-build contract and included as a specific project
commitment in the final NEPA document Clearing and grubbing should be minimized
to the greatest extent practicable without impacting safety considerations Soil erosion
and sediment control measures should be installed as soon as possible and properly
maintained during construction Installation of temporary sediment basins or other types
of sediment catchments should be considered, designed and installed to eliminate any
downstream sedimentation into Northeast Creek from Burdens Creek or Kit Creek
Compensatory Mitigation under the Clean Water Act
NCTA and FHWA propose to utilize the Ecosystem Enhancement Program's
(EEP) In-Lieu Fee program (ILF) If NCTA has not already done so, EPA recommends
that the NCTA contact EEP as soon as possible to ensure that EEP will have the ability to
provide the necessary linear footage of mitigation within the Cape Fear 02 watershed
The ILF is different from the NCDOTs MOA program, in that EEP does not necessarily
provide the mitigation up front. Under the Memorandum of Understanding (MOU) for
the II-F, mitigation for an impact is to be provided within a year from the end of the state
fiscal year in which the fee is collected If NCTA pays the fee for the mitigation before
July 1 this year (2008), then EEP will be required to institute the mitigation by June 30,
2009 If NCTA pays the fee on or after July 1, then EEP will have until June 30, 2010
This is a very large impact for the ILF program to compensate As DWQ anticipates
requiring compensatory mitigation for intermittent streams in the next few months, it is
likely that NCTA will need to provide-mitigation in an amount over 13,000 linear feet
This is a substantial amount of stream linear footage for the ELF program Currently,
EEP does not have a surplus in this watershed, and would likely have to find a site or
many sites to adequately compensate for these impacts Early coordination with EEP is
necessary to ensure that they will be able to provide this substantial amount of stream
mitigation within the time-frame required by the ILF MOU

In Section 3.10.1 on Page 3-10 (second to last bullet), the DA lists two new box
culverts measuring" 29 feet by 7 feet' It appears that this is a typographical error and there
are two (2) 'Yx7 culverts This measurement should be corrected in the final NEPA
document
Other Mitigation
While not specifically required under the Clean Water Act, FHWA regulations
and policy recommend that mitigation be considered for all project impacts There is an
estimated 3 4-acre impact to SNHA Site ID #2527 for the Hopson Road Interchange
FHWA and NCTA should consider working with the Research Triangle Foundation
(RTF) and other land use planning entities to fully compensate for this regionally
important natural resource loss within the RTP Study area There are several regionally
important plant species associated with this SNHA that could be lost as a result of habitat
destruction
Utility Impacts
It is unclear from the EA if utility relocations are expected to increase project
impacts to wetlands and streams At least 15 individual utility entities have been
identified as having utilities that will require at least some relocation, including water and
sewer lines, electrical transmission lines, natural gas lines, communication and cable
lines, etc The EA cites that $5 5 million of the total project cost is for utilities (Page 3-
13) EPA requests that impacts to wetlands and streams be evaluated in detail and
provided to interested and regulatory parties before a final NEPA decision is made
Sidewalks and Multi-Use Paths
The EA states that sidewalks and multi-use paths are not included in the Triangle
Parkway design and that such activities are not compatible with a multi-lane controlled
access freeway facility EPA notes that NCTA will replace the multi-use path along the
north side of Davis Drive with sidewalks to maintain a connection along the existing
multi-use path Future sidewalks are also planned to be accommodated along Hopson
Road The new bridge proposed over NC 54 includes sidewalks on both sides of the
bridge to connect to existing sidewalks along NC 54 The 2030 CAMPO Long Range
Transportation Plan Bike Element (June of 2005) indicates that many of the roads
surrounding and within the project study area need improvements for bicycle
accommodations CAMPOs Bicycle and Pedestrian Plan indicates that NC 54, NC 55,
and Davis Drive are'Pnonty Corridors of Greater Needs' It is unclear to EPA how the
currently designed Triangle Parkway fits into the comprehensive transportation plans for
the study area
Air Quality Analysis
EPA requests 3 copies of the study entitled `Air Quality Analysis-Triangle
Parkway from Northern Wake Expressway to I-4(J, dated June 2007, which was
- incorporated by reference One copy should be-directlyiwowded to Ms. Amanetta Wood
in EPA Region 4s Air Pesticides and Toxic Management Division Another copy should
be provided to Mr Christopher Militscher of my staff in Raleigh, N C The third copy
should be provided to me at the above referenced address
EPA notes that additional information on the prolecfs impacts to ozone is needed
The EA fully addresses predicted 1-hour and 8-hour Carbon monoxide (CO)
concentrations on Pages 5-18 and 5-19, but fails to provide predicted values for the 8-
hour Ozone concentration
Mobile Source Air Toxics
There are detailed comments attached (See Attachment 2) from EPA Region 4's
Air Toxics Assessment and Implementation Section on the EA NCTA and FHWA
should address all of the issues raised prior to making a final NEPA decision for the
project
One of the most important aspects of NEPA planning is the description of the
existing affected environment EPA believes that the MSATS analysis can be very useful
in the evaluation of alternatives Section 4 3 5 on MSATs should better describe the
existing conditions (e g , Location of any potential sensitive receptors, topography,
background concentrations, existing potential exposures, etc ) Section 5 1 14 identifies
the childcare facility known as the RTI Parenfs Child Care Cooperative Organization, but
no specific location or description is provided The EA should provide descriptions of
sensitive receptors like childcare facilities and provide the approximate location
compared to the property line or to the proposed centerline of the proposed Triangle
Parkway, or any other readily available information It is difficult to discern between the
above referenced childcare facility and the First Environments Early Learning Center
(FEELC) in the NIEHS building A noise barrier has been determined to be feasible at
the FEELC location (Section 3 11, et al ), so there is a figure reference to this facility
However, Figure A-4 should have been detailed to include the location of the daycare
facility (e g , Near the identification box citing,`Retaining Wall and Noise Sensitive
Ared)
In summary, the MSAT analysis provided in the EA is not adequate for the
purposes of determining the potential effects of the new multi-lane toll road on sensitive
receptors and what specific minimization and mitigation measures might be required to
off-set these potentially adverse air quality impacts We recommend that the FHWA and
NCTA employ the Air Toxic Risk Assessment Reference Library approach to evaluate
the potential for health effects and inform mitigation efforts to avoid health impacts such
as those that have been associated, in epidemiological studies, with exposure near
roadways We strongly encourage FHWA and NCTA to locate and design the roadway to
mimmize the impacts on sensitive receptors Minimization measures should include the
construction of barriers of adequate dimensions to potentially reduce near-road noise and
air emissions and maintaining/planting vegetative (treed) buffers between the edge of the
pavement and sensitive receptors Additional minimization measures that should be
considered include reducing lane, median and/or shoulder widths, providing retaining
walls and guardrails up to the paved outside shoulder and other engineering designs and
controls to reduce the overall road footprint
-- Attachment 2- - - -
Air Toxics Assessment and Implementation Section
In Collaboration With
Office of Transportation Air Quality
Comments on the February 2008
Triangle Parkway Environmental Assessment
Page 1-2, §1.3 notes that, "Even if the Triangle parkway project and all other planned
projects are implemented, there will still be congestion on the network " There may be
so much congestion, in fact, that on Page iv, the EA notes that "Time-of-day or peak-
period (sometimes known as `value pricing') can be used as a congestion management
option, with toll prices higher for peak travel times and lower for off-peak hours " An
important reason for this congestion is the growth in population projected by the North
Carolina Demographics Unit for Durham and Wake Counties in the period between 2000
and 2030 Population increases are projected to be 48 3% and 123 7% respectively for
those counties In the event that the parkway is not built, the volume of traffic will
exceed the capacity of all eight of the roadway links evaluated (V/C ratio) significantly
(page 1-16, Table 1-4), and as a result, the Level of Service on roadway links in the area
is predicted to be at a LOS F (serious congestion - page 1-14, Table 1-3) If the parkway
is constructed, the V/C ratio for seven of these eight roadway links will remain
significantly over 10 (i e , significantly over capacity), and the eighth roadway link is
virtually at capacity The Triangle Parkway is projected to be nearly at capacity (V/C
ratios of 0 87 to 0 93)
The purpose and need for this project are to (page2-2)
• improve mobility, accessibility, and connectivity to Research Triangle Park
employment center, and
• reduce congestion on existing north-south routes that serve the Triangle Region,
primarily NC 55 and NC 54
The EA goes on to say (page 2-2, §2.2), "To meet these elements of the purpose and
need, an alternative must provide more than a minor improvement Alternatives that
provide only a minor improvement do not meet the purpose and need and therefore are
not reasonable alternatives "
While the congestion on NC 54 and 55 is expected to be reduced through this project,
traffic will still significantly exceed the roads' capacities This raises the question of
whether a more durable improvement for the congestion problem should be identified
Page 2-9 §2 2 4 states that, "improved bus service, even if successful in attracting
additional riders, would not be sufficient to reduce congestion on NC 54 and NC 55 to a
noticeable extent because bus trips make up such a small fraction of all commuter trips "
It also states that, "while shuttle services could provide better access to RTP for those
who take transit, that improvement would affect only a small fraction of all commuter
trips to the RTP campus Therefore, thus alternative (bus transit) would not meet the
purpose of improving access for commuters to RTP, nor would it meet the purpose of
reducing congestion on NC 54 and NC 55 For these reasons, this alternative is not
reasonable and is not carved forward for detailed study " The section goes on to say
that, "Implementing a Regional Rail System in the Triangle region could improve access
for commuters to RTP (if the rail service includes a station on the RTP campus) In
addition, if the Rail System was implemented in its entirety, it eventually could help
reduce congestion on the north-south roadways within the study area, such as NC54 and
NC55 However, even with the Rail System in place, the Triangle Regional Travel
Demand Model still projects an increase of 53 to 60 percent in traffic volumes within this
same area by 2030 Implementing the Rail System alone would not provide improved
access into the RTP campus from existing commuter routes, such as 1-40 and NC 54
Therefore, while a Rail System would have benefits, it would not meet the needs for this
proposed action Based on this finding, the Mass Transit Alternative was determined to
be an unreasonable alternative for this project and was eliminated from further
consideration "
We understand that the Special Transit Advisory Commission has prepared a draft report
for the Capital Area Metropolitan Planning Organization and the Durham-Chapel Hill-
Carrboro Metropolitan Planning Organization that was updated February 28, 2008 at
http //www transitbluepnnt org/stac shtml This plan offers options that should be
considered with respect to the parkway, because the plan involves bus and rail service
that would serve the RTP area as well as the Triangle region Transit offers the prospect
of transportation options that can serve all ages and economic strata, while reducing the
air pollution impacts as well as congestion These options involve buses that could use
roads such as the parkway as well as rail connections The draft report indicates that the
region has already evaluated some of the transit options While the EA finds that bus
service or rail service alone will not solve the congestion issues in the area, it also
indicates that the parkway alone will not solve these issues
It would appear that an effective transportation plan will require a coordinated collection
of efforts involving roads, buses, rail, and other solutions An effective plan will require
collaboration among those with different perspectives and consideration of the larger
transportation picture in the area As the cost of gasoline and diesel fuel rises, options that
previously were discarded may be reconsidered The EA should consider the Special
Transit Advisory Commission report and how collaboration between the parkway
planners and the Special Transit Advisory Commission might work to the benefit of
commuters in the area The analyses presented in the EA suggest that the capacity of the
transportation system must be increased
The EA should consider the costs and benefits of increasing capacity through road
construction alone vs. through a plan that incorporates a collection of complementary
approaches simultaneously. Determining the effectiveness of projects in isolation
from one another and on a piece meal basis is likely to be a less effective approach
than one that considers the transit situation comprehensively. Road and transit (bus
-and rail) options (and combinations of road and transit) should be considered with,
quantitative evaluation of all their pros and cons, including
impact on congestion as population of the area grows
comprehensive cost analysis
o all sources of funding (e g , toll road fees, transit fares, state
appropriations, Federal Transit Administration grants, etc )
o cost of constructing and maintaining infrastructure
o time delays resulting from traffic congestion and resulting reductions in
personal and business productivity
o fuel consumption and costs resulting from traffic congestion and
associated with road and rail options
o insurance costs
• safety
o risk of crashes on highway
o impact on health from stress, crashes,
• environmental analysis
o all the analyses that should be included in an EA or EIS
o evaluation of uncontrolled emissions during operation of each of the
alternatives
o impact on air and water quality and resulting impacts on health
(The draft EA acknowledges the importance of evaluating many of these considerations
on Page 2-1 and 2-2 §2 12 )
Page 3-12 §3.11 states that the final determination concerning a noise barrier will be
made later after a study is completed This uncertainty is significant, as EPA research
suggests that barriers accompanied with trees can reduce downwind concentrations of
pollutants emitted along a highway In evaluating the EA, it is important to see the plan
as the sponsor intends to carry it out Will the sponsor submit a new or supplemental EA
after such uncertainties are resolved for review by the public9
Page 3-14 §3.16 and 3.17 There are numerous approaches that will minimize the impact
of the project on the environment which are not mentioned here
This project should implement sustainable practices to the extent feasible (e.g. Green
Highways practices, recycling materials, minimal footprint, etc.). Since the project will
be constructed close to several sensitive populations and businesses, care should be
taken to avoid air quality impacts from the project to the maximum extent feasible
During construction and for the final project design, every effort should be made to avoid
air quality impacts including, but not limited to
1 A ban on open burning - all matenals that would normally be burned should be
recycled to the extent feasible to avoid health and visibility impacts
2 Minimizing dust and debris generated during construction Given the drought in
the Southeast, what measures are planned for dust suppression? What are the
potential impacts of-alternatives tQ water? These are additional reasons to
minimize the footprint of the project
3 Construction limited to the smallest footprint feasible to avoid environmental
degradation and reduce the amount of dust generated during construction
4 Maintenance of the maximum amount of trees feasible within the project nght-of-
way during construction to reduce footprint, noise and dust dispersion during
construction
5 Installation of the latest air pollution control devices on all construction
equipment (see EPA's Venfied Technologies List for diesel engines at
http //www epa gov/otaq/retrofit/venf-list htm)
6 Use of ultra low sulfur fuel exclusively for construction equipment
7 Restriction on the time that engines involved in construction may be left to idle
Numerous health studies show that populations spending significant time near large
roadways like the proposed project may be at an increased risk for a large number of
adverse health effects Air quality monitoring data collected near roads indicated that a
number of air pollutant concentrations can be highly elevated near roads, with
concentrations generally decreasing exponentially away from the road Recent studies
also indicate that the presence of noise barriers and vegetation near the road can reduce
these air quality impacts In addition, the presence of noise barriers and vegetation has
been shown to decrease noise levels, which may also contribute to these adverse effects
We have included below references to several studies addressing the adverse health
effects, elevated pollutant concentrations, and the mitigating effects of noise barriers and
vegetation on air quality
As a result of this large body of evidence, the project should be located as far away
from sensitive receptors as possible, with a commitment to constructing adequate noise
barriers and maintaining the maximum amount of trees possible within the project's
right-of-way between the road and these sensitive populations
The sponsor and F1 WA should incorporate these and other approaches to mitigate the
impact of the project on the area The mitigative measures should not be limited to
restricting the use of neighboring land that is not owned by the sponsor (Page 5-16
§5 1 13)
Page 4-20 Table 4-13 Note that the ozone standard has changed and is now 0 075ppm
Page 4-21 §4.3.5 states that limitations in the tools and techniques for assessing project-
specific health impacts from MSATs impede FHWA's ability to evaluate how mobile
source health risks should factor into project level decision making under NEPA It also
refers to six MSAT pollutants that were appropriate for evaluation in the process How
were these six selected, since EPA does not have a current "priority MSAT" list See the
2007 MSAT rule (Regulatory Impact Analysis, Chapter 1) for further details EPA has
compiled a Master list of compounds emitted by mobile sources based on an extensive
review of the literature on exhaust and evaporative emissions from on road and non road
equipment This list currently includes approximately 1000 compounds and is available
at littp //epa gov/otaq/toxics htm The tools and techniques necessary for project specific
health impact analyses do exist, as noted below
Page 5-5 §5.1.2 notes that bicycle and pedestrian accommodations are not proposed
along the freeway section of the parkway Will bicycle and pedestrian accommodations
be installed in safe areas paralleling the parkway to encourage their use? Such
alternatives benefit not only the user, but also the environment by reducing the pollutants
emitted by commuters
Page 5-10 §5.1.11 states that the parkway project could benefit public transportation
services by providing an additional choice in routes through RTP Please elaborate on
this statement
Page 5-16 §5.1.13 states under Other Mitigation Measures Considered, "The use of
buffer zones to minimize impacts to future sensitive areas is not recommended because
this could be accomplished through land use control " The EA notes that the cost to
acquire the land would exceed an abatement threshold Does the "abatement threshold"
account for relevant public health impacts that traffic-related air pollutants might have on
adjoining populations? If the parkway does not plan to purchase the land, but anticipates
land use restrictions for the land, is this not assuming an encumbrance on land that the
sponsor does not own? What authority do the parkway planners have to impose this land
use restriction? Has the sponsor consulted with the owners of the land concerning such a
restriction?
Page 5-19 §5.1.14 We are pleased that the FHWA has arranged an evaluation of
emissions of some air toxics associated with the project This section goes on to discuss
the reductions in air toxics emissions that will result from the regulations the EPA has
issued concerning vehicle emissions and fuel formulation Pages 5-20 and 5-23 note that
the EPA regulations are expected to result in reductions in emissions of Mobile Source
Air Toxics on a national basis of from 57% to 87% from the year 2000 to 2020, and by
46% for the affected transportation network between 2006 and 2030 It is important to
note that these are projected reductions, and they do not absolve the sponsor and FHWA
from the responsibility to protect public health from emissions associated with this
project by using appropriate mitigation measures
Page 5-20 Chart 5-1 These figures should be updated to reflect the 2007 MSAT rule,
which includes higher emissions at cold temperatures than previous analyses
Page 5-20 §5.1.14 The section on quantitative MSAT analysis states that there are
technical shortcomings that prevent reliable estimates of MSAT emissions and effects at
the project level This sentence is at variance with current practice and published
literature among emissions, air quality, and environmental health professionals
Quantitative methods do exist for estimating health impacts from roadway emissions at
the project level
Pages-22 §5.1.14 The section on MSAT analysis results notes that within the affected
transportation network VMT is expected to increase by 136% between 2006 and 2030
Given that epidemiologic studies suggest traffic volumes near homes and schools are
associated with adverse health outcomes, the changes in volumes should be presented
with a figure/map of the roadways involved The travel model and MOBILE6 2 together
can provide this level of spatial resolution It should be clear to the reader which
roadway links will have increased traffic volumes and V/C ratios and which will be
mitigated See comment below for Page 5-28
Page 5-23 §5.1.14 The top of this page says that higher emissions could be offset by
operational improvements and reduced congestion on several north-south roads Is this
statement supported by data from a regional travel model or a micro simulation of
activity on these links? If so, the data should be presented If not, the EA should explain
what evidence does support the statement
Page 5-23 §5.1.14 Below the table, the text states that regardless of the alternative
chosen, MSAT emissions will be lower than present levels as a result of EPA regulations
This information does not inform the decision between options since the EA's purpose is
to compare the impacts of those options at some point in the future, not to evaluate the
impact of the EPA regulations between today and some point in the future
Page 5-24 Chart 5-3 Are these two years likely to represent the periods of maximum
emissions? If not, the year with expected maximum emissions should be estimated
Page 5-25 The top of this page notes that," it is possible that localized increases and
decreases in MSAT emissions may occur most pronounced along the new Triangle
Parkway " This is useful information, and should be quantified How many
homes/schools/people will be brought into "close" proximity of traffic (e g within 500
meters), what segments are likely to bring populations into the greatest likelihood of
exposure? Who is upwind/downwind? What factors such as barriers and vegetation are
likely to affect exposure?
Page 5-25 The second full paragraph states that available technical tools do not allow us
to reliably predict project specific health impacts While it is correct that these tools do
not predict health impacts, they do allow a comparison of potential impacts among
alternatives The thrust of the text is at variance with the common practice of air quality
and environmental health professionals, as reflected in the body of peer-reviewed
literature employing these various models
In particular, the NCHRP report referenced below (now final) represents the views of air
quality modeling and risk assessment experts, and reaches conclusions vastly divergent
from those in this and the following pages i The text also contradicts EPA and other
international governmental publications on air toxics 2
i Carr, E L , Ernst, D A, Rosenbaum, A, Glass, G , Hartley, S (2007) Analyzing, documenting, and
communicating the impacts of mobile source air toxic emissions in the NEPA process Report under
NCHRP project 25-25 Note that the authors from ICF International have developed air quality models
Page 5-25 The section "Information that is Unavailable or Incomplete" says that EPA's
tools to estimate MSAT emissions are not sensitive to key variables associated with
highway projects This comment applies only to MOBILE6 2's emission factor for PM
and pollutants linked to PM via the "ADDITIONAL RAPS" command MOBILE6 2's
PM emission factors are not sensitive to speed, so any increase in traffic volume results in
increased emissions Traffic smoothing is not reflected The comment does not apply to
emission factors for any other pollutant, including MSATs
Page 5-25 The "Emissions" section goes on to say that MOBILE6 2 has limited
applicability at the project level,
" is a trip-based model-emission factors are projected based on a typical trip
of 7 5 miles, and on average speeds for this typical trip This means that
MOBILE6 2 does not have the ability to predict emission factors for a specific
vehicle operating condition at a specific location at a specific time Because of
this limitation, MOBILE6 2 can only approximate the operating speeds and levels
of congestion likely to be present on the largest-scale projects, and cannot
adequately capture emissions effects of smaller projects "
This description of MOBILE6 2 is incorrect According to EPA's "Technical Guidance
on the Use of MOBILE6 2 for Emission Inventory Preparation, " "MOBILE6 2 has an
'AVERAGE SPEED' command which is intended specifically to assist users in modeling
individual roadway links "
This statement also contradicts the opinion of emission modeling experts (Bai et al ,
2007, Atmos Environ) "Note that a consistent link level interface (with activity from
travel models] can be attained if trip-based emission factors are converted to link based
specifications The latest MOBILE model (MOBILE6 2) reflects such a conversion for its
previous versions, which now specifies emission factors for different facility types"3
The text misconstrues the need for emissions "at a specific location at a specific time "
Numerous scientific articles have used emission factor models like MOBILE6 2 to
predict air pollutant concentrations at receptors with high spatial resolution, resulting
from vehicle activity on specific road links without the need for emission factors at the
resolution described in the policy text (i a modal emission rates)
The comment that MOBILE6 2 cannot describe emissions associated with specific
operating conditions is not relevant here and should be deleted, as none of the traffic
modeling approaches discussed herein provides information on vehicle operations at this
level of detail (e g traffic micro simulation)
employed by EPA, and include past presidents of professional environmental health societies (Arlene
Rosenbaum is past president of the International Society for Exposure Analysis)
2 EPA (2004) Air Toxics Risk Assessment Reference Library Volume 1 Technical Resource Manual
Report number EPA-453-K-04-001A [Online at http //www epa gov/ttn/fera/risk_atra_voll htmil This
document has been extensively peer-reviewed
3 Bai, S , Chiu, Y-C , Niemeier, D A (In press) A comparative analysis of using trip-based versus link-
based tratfic data fro regional mobile source emissions estimation Atmospheric Environment [Online at
http //dx doi org doi 10 1016/ atmosenv 2007 05 05 1 J
The section continues, "Also the emission rates used in MOBILE6 2 for both particulate
matter and MSATs are based on a limited number of tests of mostly older-technology
vehicles " While the data obtained on the fractions of total organic gas (TOG) comprised
by individual toxics were collected in the early 1990s, there is no a peon basis for
asserting that these toxic fractions are not applicable to current vehicles MOBILE6 2's
emission factors for VOCs, CO, and NOx are based upon extensive testing of recent
model year vehicles
One study from Connecticut that evaluated the performance of the toxic ratios within
MOBILE6 2 using ambient data concluded that modeled and monitored data "were in
good agreement "4
In a report to FHWA, Tamura et al reported finding no consistent and substantial bias in
MOBII.E6 2 emission rates for benzene and 1,3-butadiene, and were unable to evaluate
aldehyde rates 5
The issues raised in the EA are inconsistent with these recent reports suggesting no
systematic errors with the MOBILE6 2 model Hence the statement at the beginning of
the second paragraph, "These deficiencies compromise the capability of MOBME6 2 to
estimate MSAT emissions" should be deleted
Page 5-26 The "Dispersion" section states that,
EPA's current regulatory models, CALINE3 and CAL3QHC, were developed and
validated more than a decade ago for the purpose of predicting episodic
concentrations of carbon monoxide to determine compliance with the NAAQS
The purpose of model development was not NAAQS compliance per se Also,
historically it should be noted that the algorithms were derived on the basis of
experiments such as the GM sulfate experiments, which involved non-CO (particulate)
species 6
Dispersion of a pollutant is not dependent on molecular properties For instance, in the
National Air Toxics Assessment for 1999, EPA modeled nearly 200 compounds using
dispersion models evaluated using other contaminant and tracer gas data
Page 5-26 The "Dispersion" section goes on to say,
s Nadim, F , Iranmahboob, J , Holmen, B , Hoag, G E , Perkins, C , Dahmam, A M (2003) Application of
computer models to assess the effects of emission-reduction programs for a sustainable urban air quality
management Conference paper Application of Technology in Urban Development, Iranian Academic
Association December 21-28, 2003
5 Tamura, T M , Hafner, H R , Brown, S G , Eisinger, D S (2005) Investigation of consistency between
ambient monitoring data and MOBILE6 2 emissions predictions for air toxics Sonoma Technologies, Inc
Final Report STI-903632-2621-FR Prepared for Federal Highways Administration, Office of Natural
Environment
6 Chock, D P (1978) A simple line-source model for dispersion near roadways Atmos Environ (1967) 12
823-829
The performance of clispersioa models is more accurate for predicting maximum
concentrations that can occur at some time at some location within a geographic
area
This assessment of model performance is at variance with numerous studies conducting
comparisons between modeled and monitored concentrations at a particular location
The emphasis on "more accurate" also fails to note that in Appendix W to 40 CFR Part
51, EPA concludes that CALINE3 is applicable to "primary pollutants," without such
caveats provided here
Page 5-26 The "Dispersion" section continues,
This limitation makes it difficult to predict accurate exposure patterns at specific
times at specific highway project locations across an urban area to assess potential
health risk
There are numerous applications of dispersion models for this specific purpose in
scholarly ,journals
Page 5-26 The "Dispersion" section concludes,
Along with these general limitations of dispersion models, FHWA is also faced with
a lack of monitoring data in most areas for use in establishing project-specific MSAT
background concentrations
Among the reasons for conducting modeling is the high cost and length of time required to
obtain MSAT monitoring data, However, should FHWA wish to conduct such a study in
the RTP area, EPA would be pleased to collaborate and offer technical advice
Page 5-26 The "Exposure Levels and Health Effects" section states
Finally, even if emission levels and concentrations of MSATs could be accurately
predicted, shortcomings in current techniques for exposure assessment and nsk
analysis preclude us from reaching meaningful conclusions about project-specific
health impacts
The risk assessment process was not designed to quantify actual health risk in a
community Rather, screening level risk assessments can be used to compare potential
impacts as one consideration in evaluating various alternatives
EPA published the Air Toxics Reference Library in order to assist in the screening
evaluation of air toxics exposures for health impacts That library is available at
http //www epa gov/ttn/fera/risk_atra_main html The library includes a tabulation of
toxicity values for many air toxics That table is available at
http /wv w epa go,. /ttn/,itw/tolsource/summaZ html
We urge the sponsor and FHWA to employ the Aar Toxic Risk Assessment Reference
Library's approach to evaluate the potential for health effects and inform mitigation efforts
to avoid health impacts such as those that have been associated, in epidemiological
studies, with exposures near roadways (see comment "Page 28" below).

Atiered approach to nsk analysts begins with a simple, screening-level evaluation using
health-protective exposure assumptions (e g , assuming people are located in the area
with the highest estimated concentrations over their lifetime) and relatively simple, yet
conservative, modeling If the result of this process using conservative assumptions
shows acceptably low potential risk, further analysts may not be necessary, or may be
necessary for only a limited number of HAPs which appear to pose the majority of the
risk Higher level tiers of analyses, if necessary, are more data intensive, with more
realistic (and typically less conservative) inputs, and more detailed modeling to more
accurately predict whether there may be important nsks from air toxics emissions
associated with the project Overall, this tiered approach provides the benefit of limiting
the cost of an evaluation in the event that the project's emmsstons do not pose a significant
potential risk for the public under the various alternatives being considered
These analyses would likely involve the common frameworks for evaluating the
significance of estimated air toxtcs exposures, such as the risk management framework
established in the Clean Air Act for certain stationary sources? and in the Region 4
guidance for performing screening-level assessments of air toxics monitoring datas
Page 5-26 the "Exposure Levels and Health Effects" section goes on to say
Exposure assessments are difficult because it is difficult to accurately calculate
annual concentrations of MSATs near roadways, and to determine the portion of a
year that people are actually exposed to those concentrations at a specific
location These difficulties are magnified for 70-year cancer assessments,
particularly because unsupportable assumptions would have to be made regarding
changes in travel patterns and vehicle technology (which affects emissions rates)
over a 70-year period
Refinements in modeling technology have significantly improved the ability to handle
non-sedentary mobility during the life of a given population The National-scale Air
Toxics Assessment (NATA http //www epa gov/ttn/atw/nata/index html) is one example
of this extensively robust approach towards achieving a finer measure of exposure that
reflects more life activities The 70-year averaging time for carcmogenesis reflects the
potential onset of an excess cancer that might result from exposure to a carcinogen under
a given exposure scenario Adjustments to reflect travel patterns and vehicle technology
might provide useful information in predicting a central tendency exposure outcome
However, it would be unclear whether, and if so, how the result would improve the
accuracy/protectiveness of the resulting risk characterization relative to a given
population over a lifetime
7As described in detail in the "Residual Risk Report to Congress"
(http //www epa gov/ttn/oarpg/t3/reports/nsk iep pdf)
s EPA Region 4 has published screening level health-based benchmarks for numerous air toxtcs in a
document entitled "A Preliminary Risk-based Screening Approach for Air Toxics Monitoring Data Sets"
which can be found at http //www epa gov/region4/air/airtoxic/Screening-041106-KM pdf While
developed for screening-level evaluation of monitoring data, these screening values are also appropriate for
screening-level assessment of modeling data
We have discussed estimating MSAT concentration above. In a screening level
evaluation, as noted in the Air Toxics Risk Assessment Reference Library (Volume 1)
simplifying assumptions are used to save time and costs associated with the effort In the
interest of not overlooking a potential issue, the assumptions are conservative, for
example, assuming that the person is exposed to the toxic air pollutant concentration
continuously for 70 years We recognize that this is not realistic, but it is a reasonable
conservative assumption of the type that is used routinely in screening level risk
evaluations If the potential risk identified through this process is higher than is
acceptable, a more careful evaluation using more realistic inputs can be carried out
However, in the interest of saving the sponsoring organization time and money, and in
the interest of emng on the side of public health, such assumptions are used
Page 5-26 The "Exposure Levels and Health Effects" section continues
There are also considerable uncertainties associated with the existing estimates of
toxicity of the various MSATs, because of factors such as low-dose extrapolation
and translation of occupational exposure data to the general population Because
of these shortcomings, any calculated difference in health impacts between
alternatives is likely to be much smaller than the uncertainties associated with
calculating the impacts
It is true that there is uncertainty in the toxicity estimates associated with air pollutants
This does not mean however, that these benchmarks are without accuracy and thus not
useful in risk predictions Because the toxicity assessment process is designed to be
conservative and protective of sensitive sub-populations, the resulting nsk-based safe
linuts have been used internationally to protect human health The uncertainty in hazard
assessment is sound and reflects the best current peer reviewed science
If we did not use toxicity estimates, risk assessments would not be possible
Extrapolating from higher doses to lower doses is often required to develop toxicity
estimates because it would be inappropriate (for many reasons) to intentionally expose
members of the general population to air toxics simply to obtain a more refined toxicity
number Instead, we might employ epidemiological studies carried out on people who
are exposed during the course of their work, and then extrapolate from those levels to
lower levels typical of the general public In many cases we do not have human exposure
data at all, and must resort to exposing animals to evaluate the effect of chemicals This
also involves extrapolation, but it is done systematically and deliberately by toxicologists
trained in the science This process is described to the Air Toxics Reference Library
Yes, there are shortcomings, but screening level risk assessments are a useful way to
compare alternatives and to identify potential risks that warrant further investigation with
more sophisticated risk assessment techniques Such evaluations are our opportunity to
identify potential toxic exposures that could be mitigated or avoided, and to identify those
exposures that are of no concern While uncertainties do exist in risk assessment, they
also exist in all other modeled outputs, such as travel demand and land use
Pages 5-27 to 5-2&This section should bexevised to incorporate the summary of science
in the Regulatory Impact Analysis for the Mobile Source Air Toxics Rule published in
the Federal Register February 26, 2007
Page 5-28 The first full paragraph notes that, "Some recent studies have reported that
proximity to roadways is related to adverse health outcomes - particularly respiratory
problems " The section goes on to say,
The FHWA cannot evaluate the validity of these studies, but more importantly,
they do not provide information that would be useful to alleviate the uncertainties
listed above and enable us to perform a more reliable, comprehensive evaluation
of the health impacts specific to this project
It should be noted that there are hundreds of studies that have been published dust since
2000 associating proximity to roadways with a number of adverse health effects
including respiratory, birth and developmental effects, cardiovascular, premature
mortality, and cancer Baldauf et al provided a summary of a number of these studies at
the Transportation Research Board's Air Quality and Land Use Planning Conference in
2007 (Traffic Emission Impacts on Air Quality Near Large Roadways Proceedings the
Transportation Research Board Planning and Air Quality Conference, July 9-11, 2007)
While these studies may not implicate specific pollutants as resulting in the adverse
effects, they do implicate proximity as a key factor
The 2004 statement on air pollution by the American Academy of Pediatrics states,
" [s]iting of school and child care facilities should include consideration of proximity to
roads with heavy traffic and other sources of air pollution New schools should be
located to avoid "hot spots" of localized pollution "
Several recent reviews of epidemiologic literature conclude that residence near major
roads is associated with a range of adverse health effects. Given these statements in
publications by medical societies and environmental health researchers, for residents near
mayor transportation infrastructure, a public health concern exists at present 9 10 It 12 13
Recent reviews involving near-road health effects can be found in the literature'a?is 16 17
18 19
9 Adar, S D , Kauffman, J D (2007) Cardiovascular disease and air pollutants evaluating and improving
eeidemiological data implicating traffic exposure Inhal Toxicol 19 (Suppl 1) 135-149
Samet, J M (2007) Traffic, air pollution, and health Inhal Toxicol 19 1021-1027
Tonne, C , Beevers, S , Armstrong, B G , Kelly, F , Wilkinson, P (2008) Air pollution and mortality
benefits of the London Congestion Charge spatial and socioeconomic inequalities Occupational and
Environmental Medicine Published online February 28, 2008 [Online at http //dx dot org
dot 10 1136/oem 2007 036533]
12 Burr, M L , Karam, G , Davis, B , Holmes, B A , Williams, K L (2004) Effects on respiratory health of
a reduction in air pollution from vehicle exhaust emissions Occupational and Environmental Medicine 61
212-218
i' Lwebuga-Mukasa, J S , Oyana, T , Thenappan, A , Ayirookuzhi, S J (2004) Association between traffic
volume and health care use for asthma among residents at a U S -Canadian border crossing point Journal
of Asthma 41 289-304
14 Salam, M T et al (2008) Recent evidence for adverse effects of residential proximity to traffic sources
on asthma Current Opin Pulmonary Med 14(1) 3-8
This area of research should be discussed-in detail in the EA. Discussion ofthese -
health concerns should not be limited to MSA Ts, though MSAT analyses may help
identify populations at potential risk and devise mitigation strategies.
EPA's 2007 MSAT rule discusses these studies and is current through February 2007
Section 3 5 of the Regulatory Impact Analysis addresses these studies in greater detail
Supporting information on air quality near roads and the effects of noise barriers
and vegetation on near road air quality
Motor vehicles influence the concentrations of criteria pollutants, air toxic pollutants
(including MSATs), and particulate matter (PM as a criteria pollutant and air toxic
component) concentrations within urban areas Emissions from motor vehicle operations
may lead to elevated concentrations of particular air pollutants near mayor roads Air
quality monitoring studies have detected elevated levels of carbon monoxide (CO), nitric
oxides (NO,,), nitrogen dioxide (NOD, coarse (PM10-25), fine (PM25), and ultrafine
(PM01) particle mass, black carbon (BC), polycyclic aromatic hydrocarbons (PAHs), and
benzene near large roadways, as compared to overall urban background levels 20 21 22 23 24
25 Several recent studies have focused on PM measurements, identifying elevated
15 Adar, S D, Kauffman, J D (2007) Cardiovascular disease and air pollutants evaluating and improving
eridemiological data implicating traffic exposure Inhal Toxicol 19 (Suppl 1) 135-149
1 Samet, J M (2007) Traffic, air pollution, and health Inhal Toxicol 19 1021-1027
17 Heinrich and Wichmann, 2004, Curr Opin Allergy Clin Immunol 4 341-8,
18 Raaschou-Nielson and Reynolds, 2006, Int J Cancer 118 2920-9
19 American Academy of Pediatrics Committee on Environmental Health, 2004, Pediatrics 114 1699-
1707
20 Duci, A, Chaloulakou, A, Spyrellis, N, 2003 Exposure to carbon monoxide in the Athens urban area
during commuting The Science of the total environment 309, 47-58
2' Gilbert, N L , Woodhouse, S , Stieb, D M , Brook, J M 2003 Ambient nitrogen dioxide and distance
from a major highway The Science of the total environment 312(1-3), 43-46
22 Giugliano, M, Lonati, G, Butelli, P, Romele, L, Tardivo, R , Grosso, M, 2005 Fine particulate
(PM2 5-PM1) at urban sites with different traffic exposure Atmospheric Environment 39 2421-2431
23 Harrison, R M, Tilling, R, Callen Romero, M S, Harrad, S, Jarvis, K 2003 A study of trace metals
and polycyclic aromatic hydrocarbons in the roadside environment Atmospheric Environment 37, 2391-
2402
24 Kim, J J , Smorodinsky, S , Lipsett, M , Singer, B C , Hogdson, A T , Ostro, B , 2004 Traffic-related Air
Pollution Near Busy Roads The East Bay Children's Respiratory Health Study American Journal of
Respiratory and Critical Care Medicine 170(5), 520-526
25 Reponen, T, Grinshpun, S A, Trakumas, S , Martuzevicius, D, Wang, Z M , LeMasters, G , Lockey,
J E , Biswas, P , 2003 Concentration gradient patterns of aerosol particles near interstate highways in the
Greater Cincinnati airshed Journal of Environmental Monitoring 5(4), 557-562
ultrafine particle number concentrations-in primly to-the-roadway 26 27 28Other
studies have noted that PM concentrations in the ultrafine, fine, and coarse modes may be
elevated near mayor roads 29 30 These studies suggest that elevated concentrations occur
within several hundred meters of the road, although the extent of elevated concentrations
will likely vary depending on traffic conditions, environmental conditions, topography,
and structures present near the road In addition to air pollutants, the presence of non-
specific stressors (i a noise) may be increased for populations living near roads Figure 1
provides an example of typical elevated pollutant concentrations measured near roads,
with linear and/or exponential decreases in concentrations with distance
1.0
08
04
02
00
Zhu et al , 2002
06
ParWS Nl VMW

t
Bloc* Carbon
Upwind •200 -100 0 100 240 300 Do%%-nwtwd
D}iatuamc to the 710 Ftenwray (m)
Figure 1 Changes in CO, BC and PM number concentrations measured in Los Angeles,
CA as a function of distance from the road This figure highlights the elevated
concentrations of these traffic emitted pollutants, as well as the exponential decrease in
26 Zhu, Y , Hinds, W C , Kim, S K, Shen, S, Sioutas, C, 2002 Study of ultrafine particles near a major
highway with heavy-duty diesel traffic Atmospheric Environment 36,4323-4335
27 Zhu, Y , Hinds, W C , Kim, S K , Sioutas, C , 2002 Concentration and size distnbution of ultrafine
particles near a mayor highway Journal of the Air & Waste Management Association 52, 1032-1042
28Reponen, T , Gnnshpun, S A Trakumas, S , Martuzevicius, D, Wang, Z M, LeMasters, G, Lockey,
J E , Biswas, P , 2003 Concentration gradient patterns of aerosol particles near interstate highways in the
Greater Cincinnati airshed Journal of Environmental Monitoring 5(4), 557-562
29 Kittelson, D B , Watts, W F, Johnson, J P, 2004 Nanoparticle emissions on Minnesota highways
Atmospheric Environment 38(l),9-19
30 Zhang, K M , Wexler, A S , Zhu, Y F , Hinds, W C , Sioutas, C (2004) Evolution of particle number
distribution near roadways Part 11 the 'Road-to-Ambient' process Atmos Environ 38 6655-6665
concentrations with distance. This figure also highlights the inter-relationship of CO
with potential surrogate measurements of BC and PM number (Zhu et al 31)
Roadway design can influence the amount of emissions generated from motor vehicles as
well as the transport and dispersion of the pollutants from the road Factors of roadway
design that can impact emissions include road grades, ramps, intersections, sharp curves,
and merge locations Road grades create a potential increased load on vehicles ascending
the grade leading to increased exhaust emissions, while vehicles descending the grade
may experience increased brake emissions The presence of ramps, intersections, curves,
and lane merge locations may also lead to increased brake wear emissions, idling vehicle
conditions due to increased congestion, and accelerations to reach prevailing speeds The
type of pavement on the road may also affect the amount of re-suspended road dust,
while asphalt pavements also emit small levels of VOCs
The topography around the roadway will influence pollutant transport and dispersion
away from the road At-grade roadways will experience the least amount of resistance to
pollutant dispersion if no other structures exist near the road (see next section) However,
cut section roads, whether vertical or sloped cut walls, will increase the number of
vortices created by wind flow into and along the cut section roadway, potentially
increasing pollutant dispersion In addition, as winds flow up and out of the cut section,
the plume off the roadway may be more elevated than under an at grade condition
Figure 2 shows an example from a wind tunnel study comparing roadway design
configurations and changes in near road air pollutant concentrations to illustrate these
effects The figure shows that emissions from motor vehicles in a cut section with a 6m
or higher noise barrier at the top of the cut section result in the lowest air pollutant
concentrations for the scenarios evaluated.
31 Zhu, Y , Hinds, W C , Kim, S K , Shen, S , Sioutas, C , 2002 Study of ultrafine particles near a mayor
highway with heavy-duty diesel traffic Atmospheric Environment 36, 4323-4335
Zhu, Y, Hinds, W C , Kim, S K, Sioutas, C, 2002 Concentration and size distribution of ultrafine
particles near a major highway Journal of the Air & Waste Management Association 52, 1032-1042
C
O
O
V
C
O
U
O
t.
O
wJ
20
r;
15=
10
-M- Flat terrain
-'V Noise barrier, upwind and downwind
-+- Depressed roadway (6m), vertical walls
----)-- Depressed roadway (6m), 30 deg slope
--E)- Depressed roadway (6m), 30 deg, with bamers
7
00 10 20
XIH
40
Figure 2 Wind tunnel study results comparing downwind air pollutant concentrations
from a road at-grade with no obstructions to airflow with roadway configurations
containing varying topography and roadside structures For this figure, the distance from
the road is related to the height of the noise barrier evaluated (6 meters), thus, the
distances listed along the x-axis should be multiplied by a factor of 6 to get the actual
distance (in meters) from the road edge These results represent winds perpendicular
from the road at a speed of 3 m/s 32
In addition to topographic feature changes near the road, structures may be present that
impact pollutant transport and dispersion These structures may include noise barriers
and vegetation As shown in the wind tunnel results, these physical barriers may affect
pollutant concentrations around the structure by blocking initial dispersion, and
increasing turbulence and initial mixing of the emitted pollutants Figure 3 illustrates the
potential effects of roadside barriers using fluid dynamics modelling
Noise barriers reduce noise levels from traffic by blocking and deflecting sound waves
These barriers may also affect air pollutant dispersion, leading to increased vertical
mixing due to the upward deflection of air flow caused by the structure Studies suggest
that this upward deflection of air may create a recirculation cavity downwind of the
barrier containing a well-mixed, and often lower, zone of pollution concentrations
32 Wind Tunnel Simulations of Pollution from Roadways D K Heist, S G Perry, L A Bnxey, and
G E Bowker Proceedings of the International Workshop on Physical Modelling of Flow and Dispersion
Phenomena (PHYSMOD 2007) pp 63-68 Orleans, France August, 2007
However, noise barriers adjacent to a roadway may also tnhibit air movements off the
road, leading to elevated on-road pollutant concentrations 33 34 35 36 37 38 39
Vegetation stands will also affect near-road pollutant concentrations The complex and
porous structure of tree limbs and leaves will likely increase air turbulence and promote
mixing and dispersion Trees and other vegetation may also reduce pollutant
concentrations by enhancing deposition of certain pollutants, notably PM components
Variables such as the type of vegetation, plant height, and vegetation thickness will likely
influence the extent of mixing and deposition experienced at the site, although specific
relationships of these factors have not been identified 40 41 42 43 44 45
33 Tan, K T , Lepp, N W , 1977 Roadside vegetation an efficient barrier to the lateral spread of
atmospheric lead9 Arboricultural Journal 3(2), 79-85
34 Nokes, W A, Benson, P E , 1984 Carbon monoxide concentrations adjacent to sound barriers Office of
Transportation Laboratory, Califorma Department of Transportation Report FHWA/CA/TL-84104
35 Lidman, J K, 1985 Effect of a Noise Wall on Snow Accumulation and Air Quality Transportation
Research Record 1033, 79-88
36 Paul-Carpenter, S , Barboza, M J , 1988 Effects of highway noise barriers on carbon monoxide levels
81" Annual meeting of the Air Pollution Control Association (APCA), Dallas, TX, June, 1988
37 Holscher, N , Hoffer, R , Niemann, H-J , Brilon, W , Romberg, E , 1993 Wind tunnel experiments on
micro-scale dispersion of exhausts from motorways Science of the Total Environment 134, 71-79
38 Swamy, K T Veerabhadra, Lokesh, K S , 1993 Lead dispersion studies along highways Indian Journal
of Environmental Health 35 33, 205-209
39 Bowker, G E, R W Baldauf, V Isakov, A Khlystov, W Petersen, Modeling the
effects of sound barriers and vegetation on the transport and dispersion of air pollutants
front roadways, Atmospheric Environment 2007 41 8128-8139
40 Beckett, J P , Freer-Srmth, P H , Taylor, G , 2000 Effective tree species for local air quality
management Arboriculture, 26 (1), 12-19
4i Bowker, G E , R W Baldauf, V Isakov, A Khlystov, W Petersen, Modeling the effects of soured
barriers and vegetation on the transport and dispersion of air pollutants from roadways, Atmospheric
Environment 2007 41 8128-8139
42 Bussotti F, Grossomi, P, Batistoni, P , Ferretti, M , Cenni, E , 1995 Preliminary studies on the ability
of plant barriers to capture lead and cadmium of vehicular origin Aerobiologia, 11 (1), 11-18
41 Heath, B A , Matighan, J A , Morrison, A A , Eastwood, I W , Drew, I B , Lofkin, M , 1999 The
Influence of Wooded Shelterbelts on the Deposition of Copper, Lead, and Zinc at Shakerley Mere,
Cheshire, England Sci Total Environ, 235 (1-3), 415(3)
44 Heichel, G H, Hankin, L, 1976 Roadside Coniferous Windbreaks as Sinks for Vehicular Lead
Emissions Journal of the Air Pollution Control Assoc, 26 (8), 767-770
4' Munch, D, 1993 Concentration Profiles of Arsenic, Cadmium, Chromium, Copper, Lead, Mercury,
Nickel, Zinc, Vanadium, and PAH in Forest Soil Beside an Urban Road Sci Total Environ, 138 (1-3), 7-
55
a) 30
25
t 20
o,
x
1s
10
51
0
b) 30
25
E
V_ 20
rn
as
x
,. 15
10
5
O
C) 30
25
E
20
rn
a,
x
15
10
S
O
South-North distance (m)
3
O 005 010 015 O 20 O 25 030 Y 035 040 O 45 ?O 50
Normalized concentrations
Figure 3 Fluid dynamic modelling comparing (a) an at-grade road with no obstructions
to airflow with (b) a roadway with only a noise barrier and (c) a roadway with a noise
barrier, trees, and buildings This figure shows the potential cavity zone behind a noise
South-North distance (m)
South-North distance (m)
< ? 4 ^ r
barrier, as well as the enhanced mixing that occurs with the presence of vegetation and
buildings near the road 46)
900 --- -- -- -?
800 20 nm size particles
-*-Open Field I
700 -E-- Noise Barner Only
E -A- Noise Barner & Vegetation
L 600
m i
E 500
cvCi 400
c
v 300 i
m 200
100
0
0 0 0 0 0 0 0 0 N0 0 0 0 0
r
N N N N N N M
Distance from 1-440 (m)
Figure 4 Mobile monitoring measurements of the number of 20 nm size particles present
at varying distances from the road for an at-grade roadway with no obstructions (open
field), behind only a noise bamer (noise barrier only), and behind a noise barrier with
mature vegetation and detached single story houses (noise bamer & vegetation) Bars
represent 95 percent confidence intervals for each distance 47
Figures 3 and 4 show that the combination of noise barriers and trees will likely reduce
pollutant concentrations near roads when compared to situations with no barriers or trees
A noise bamer alone may reduce concentrations for a short distance behind the wall, but
concentrations can increase further from the barrier if no trees are present In addition,
the cavity that forms behind the wall can change with changing wind directions, so this
affect is not consistent
Regardless of the roadway design, the activity of vehicles on the road will induce
turbulence at the point of pollutant emission, leading to enhanced pollutant dispersion In
addition, the elevated temperature of exhaust emissions will enhance thermal buoyancy in
the plume This thermal and vehicle induced turbulence will provide an initial mixing
zone for vehicle emitted pollutants that will be dependent on the number, type and speed
46 Bowker, G E , R W Baldauf, V Isakov, A Khlystov, W Petersen, Modeling the effects of sound
barriers and vegetation on the transport and dispersion of air pollutants front roadwavs, Atmospheric
Environment 2007 41 8128-8139
47 Baldauf R W , E Thoma, A Khlystov, V Isakov, G E Bowker, T Long, R Snow, Impacts of Noise
Barriers on Near-Road Air Quality, submitted to Atmospheric Environment
of vehicles on the road The more turbulence present, the more initial mixing of pollutant
emissions that will occur The initial mixing and turbulence effects can lead to increased
pollutant concentrations upwind of the road As discussed in Venkatram et al 4s, (2007),
elevated pollutant concentrations can occur in close proximity of the highway whether
the wind is blowing to or from the road
i
ae Venkatram, A, V Isakov*, E Thoma, R W Baldauf, Analvsis of air quality data near roadways using a
dispersion model, Atmospheric Environment 2007 41 9481-9497