VDOT AIR QUALITY ANALYSIS DULLES AIR CARGO, PASSENGER & METRO ACCESS HIGHWAY

Transcription

1 LOUDOUN COUNTY PROJECT NUMBER: R , P0; UPC NO FEDERAL PROJECT NUMBER: STP-5A0(454) VDOT AIR QUALITY ANALYSIS SUBMITTED PURSUANT TO 42 U.S.C. 4332(2)(C) DULLES AIR CARGO, PASSENGER & METRO ACCESS HIGHWAY PREPARED FOR Hrris Miller Miller & Hnson, Inc. 77 Sou t h Bed f ord Street B urli n g ton, MA For t Evns R od, NE Leesbur g, VA 2076 U.S. DEPARTMENT OF TRANSPORTATION FEDERAL HIGHWAY ADMINISTRATION & VIRGINIA DEPARTMENT OF TRANSPORTATION

2 AIR QUALITY ANALYSIS TECHNICAL REPORT Dulles Air-Crgo, Pssenger nd Metro Access Highwy Loudoun County, Virgini HMMH Report No Februry 25, 204 Prepred for: Virgini Deprtment of Trnsporttion 40 Est Brod Street Richmond, VA 2329 VDOT Project No. R , P0 UPC No Prepred by: Hrris Miller Miller & Hnson Inc. 77 South Bedford Street Burlington, MA 0803 T F

3 Air Qulity Technicl Report Dulles Air Crgo, Pssenger nd Metro Access Highwy Februry 25, 204 VDOT Project No. R , P0 Contents Executive Summry... 2 Introduction Project Description Alterntive ; No-Build Alterntive Alterntive Alterntive Alterntive 3A US Route 50 Elevted Alterntive 3B Alterntive 3C Trffic Summry Existing Conditions Meteorology Climte Regultory Stndrds Ntionl Ambient Air Qulity Stndrds Mobile Source Air Toxics Trnsporttion Conformity Project Assessment Crbon Monoxide (CO) Anlysis Methodology Intersections Studied MOVES Emissions Estimtion CAL3QHC Dispersion Model Receptors CAL3QHC Modeling Results Prticulte Mtter Mobile Source Air Toxics Anlysis Methodology MSAT Bckground Motor Vehicle Emissions Simultor (MOVES) MSAT Reserch Project MSAT Impcts Incomplete or Unvilble Informtion for Project-Specific MSAT Helth Impcts Anlysis MSAT Conclusions Construction Emission Anlysis Mitigtion Conclusions Appendix A Trffic Anlysis (Avilble Upon Request)... A- Appendix B Smple MOVES Input nd Output Files (Complete Set of Files Avilble Upon Request)... B- iii

4 Air Qulity Technicl Report Dulles Air Crgo, Pssenger nd Metro Access Highwy Februry 25, 204 VDOT Project No. R , P0 Appendix C Smple CAL3QHC Input nd Output Files (Complete Set of Files Avilble Upon Request)... C- Figures Figure. Study Are... 3 Figure 2. No-Build Alterntives nd Study Corridor... 4 Figure 3. Alterntive 2 Typicl Rodwy Section... 4 Figure 4. Alterntive 3A Typicl Rodwy Section... 5 Figure 5. Alterntive 3B Typicl Rodwy Section... 6 Figure 6. Alterntive 3C Typicl Rodwy Section... 7 Figure 7. Alterntive 3C Typicl Rodwy Section... 8 Figure 8. CAL3QHC Receptor Loctions: Evergreen Mills Rod t Belmont Ridge Rod nd Brirfield Lne... 9 Figure 9. CAL3QHC Receptor Loctions: US 50 t Gum Springs Rod Figure 0. CAL3QHC Receptor Loctions: Loudoun County Prkwy t Old Ox Rod... 2 Figure. CAL3QHC Receptor Loctions: US 50 t Loudoun County Prkwy Existing Conditions Figure 2. CAL3QHC Receptor Loctions: US 50 t Loudoun County Prkwy No-Build Conditions Figure 3. CAL3QHC Receptor Loctions: US 50 t Loudoun County Prkwy Alterntive 3A Figure 4. CAL3QHC Receptor Loctions: US 50 t Loudoun County Prkwy Alterntive 3C Figure 5. CAL3QHC Receptor Loctions: Loudoun County Prkwy t Old Ox Rod Figure 6. Ntionl MSAT Emission Trends for Vehicles Operting on Rodwys Using EPA's MOVES 200b Model Tbles Tble. Ntionl Ambient Air Qulity Stndrds... 9 Tble 2. Estimted LOS nd Pek-Hourly Trffic Volumes t the Intersections/Interchnges for the 2025 nd 2040 Alterntive Conditions... 3 Tble 3. Estimted LOS nd Projected Dely Times t the Intersections for the 2025 nd 2040 Alterntive Conditions... 4 Tble 4. Estimted Trffic Volumes Entering nd Exiting ech Interchnge for the 2025 nd 2040 Alterntive Conditions... 6 Tble 5. Summry of MOVES Inputs... 7 Tble 6. Summry of CAL3QHC Inputs... 8 Tble 7. CAL3QHC Modeling Results for Ech Intersection/Interchnge Tble 8. Estimted AADT nd Diesel Truck Volumes for 2025 Alterntive Conditions... 3 Tble 9. Estimted AADT nd Diesel Truck Volumes for 2040 Alterntive Conditions iv

5 Air Qulity Technicl Report Dulles Air Crgo, Pssenger nd Metro Access Highwy Februry 25, 204 VDOT Project No. R , P0 Executive Summry The Virgini Deprtment of Trnsporttion (VDOT) is conducting study of the proposed Airport Connector Rodwy Study Alterntives ( Project ). The purpose of the Project is to enhnce the movement of pssenger nd ir crgo trffic to Wshington Dulles Interntionl Airport (IAD) in conjunction with the plnned Phse 2 extension of the Metroril Silver Line. The Project is intended to reduce congestion nd improve cpcity on the existing rodwy network in the Dulles South re. The study is being conducted to support the Environmentl Assessment (EA) of the retined lterntives. Federl funding is involved with the Project, therefore, complince with the Ntionl Environmentl Policy Act (NEPA) nd the Clen Air Act (CAA) is required. NEPA requires discussion of the trnsporttion-relted ir qulity concerns in the project re nd summry of ny crbon monoxide nlysis performed, nd the CAA requires trnsporttion conformity demonstrtion with ny Stte Implementtion Pln (SIP) for ny U.S. Environmentl Protection Agency (EPA) criteri pollutnt in non-ttinment or mintennce res. Loudoun County is locted in n EPA designted non-ttinment re for the 8-hour ozone stndrd (997 nd 2008 stndrds) nd the 997 nnul fine prticulte mtter stndrd (PM2.5). The re is designted s ttinment for ll other Ntionl Ambient Air Qulity Stndrds (NAAQS). As such, ll resonble precutions should be tken to limit the emissions of voltile orgnic compounds (VOCs) nd nitrogen oxides (NOx). In ddition, the following VDEQ ir pollution regultions will be dhered to during the construction: 9 VAC 5-30 et seq., Open Burning restrictions, 9 VAC 5-45, Article 7 et seq., Cutbck Asphlt restrictions, 9 VAC et seq. nd Fugitive Dust precutions. On Februry 20, 203 the Ntionl Cpitl Region Trnsporttion Plnning Bord (TPB) greed to include the Dulles Air Crgo, Pssenger, nd Metro Access Highwy (DACPMAH) build nd no-build lterntives for regionl ir qulity conformity testing. In Mrch 204, VDOT will formlly mke recommendtion on preferred Alterntive to the TPB for inclusion in the 204 Ntionl Cpitl Region s Finncilly Constrined Long-Rnge Pln (CLRP) which includes projected trnsit nd trffic, demogrphics, nd ir qulity conditions through the 2040 horizon yer. An ir qulity impct ssessment of crbon monoxide (CO) trffic emissions ws conducted since the verge nnul dily trffic (AADT) is estimted to be bove the pplicble thresholds in the 2009 VDOT nd Federl Highwy Administrtion (FHWA) Project-Level Crbon Monoxide Air Qulity Studies Agreement. The worst-cse CO ground level impcts were estimted t receptor loctions in close proximity to the five worst-cse intersections/interchnges in the project corridor bsed on Level of Service (LOS), trffic volumes, public ccess, nd resonbleness. The worst-cse ground level CO impcts were found to remin well below the CO NAAQS t ll modeled receptor loctions. The study re is locted in n EPA designted non-ttinment re for the 997 nnul PM2.5 stndrd; therefore, EPA s Trnsporttion Conformity Rule pplies nd n nlysis ws required to determine whether the project is considered to be one of ir qulity concern for fine prticulte mtter. Bsed on the EPA criteri specified in the Trnsporttion Conformity Rule nd ssocited EPA guidnce, the Study Alterntives re not considered to be of ir qulity concern for fine prticulte mtter. Therefore, the Clen Air Act nd 40 CFR 93.6 requirements for PM2.5 were met without the need of performing hot-spot nlysis, since projects such s this hve been found to not be ones of ir qulity concern under 40 CFR 3.23(b)(). The nlysis lso evluted potentil impcts from mobile source ir toxics (MSATs) in the Study re. Since the Build Alterntives will not dd significnt cpcity to ny of the existing nd proposed rodwy networks where design yer trffic is projected to be 40,000 to 50,000 AADT or greter, the Alterntives re best chrcterized s project with Low Potentil MSAT Effects under the 202 FHWA interim guidnce updte document. For ll Build Alterntives in the design yer, there could be slightly higher MSAT emissions in the Study re reltive to the No-Build Alterntive due to incresed

6 Air Qulity Technicl Report Dulles Air Crgo, Pssenger nd Metro Access Highwy Februry 25, 204 VDOT Project No. R , P0 VMT, nd there could lso be increses in MSAT levels in few loclized res where VMT is projected to increse. However, in ll res of the project corridor, EPA's vehicle nd fuel regultions will bring bout significntly lower MSAT levels in the future thn exist tody. Emissions produced during the construction of the Study Alterntives will be short-term or temporry in nture. In order to mitigte these emissions, construction ctivities will be performed in ccordnce with VDOT s current Rod nd Bridge Specifictions. The specifictions conform to the SIP nd require complince with ll pplicble locl, stte, nd federl regultions. 2 Introduction Potentil ir qulity impcts ssocited with the proposed Dulles Air-Crgo, Pssenger nd Metro Access Highwy (DACPMAH) Alterntives locted in Loudoun County were ssessed by Hrris Miller Miller & Hnson Inc. (HMMH). The purpose of the project is to enhnce the movement of pssenger nd ir crgo trffic to Wshington Dulles Interntionl Airport (IAD) in conjunction with the plnned Phse 2 extension of the Metroril Silver Line. The Study Alterntives re intended to reduce congestion nd improve cpcity on the existing rodwy network in the Dulles South re. Federl funding is involved with the Study Alterntives; therefore, complince with the Ntionl Environmentl Policy Act (NEPA) nd the Clen Air Act (CAA) is required. NEPA requires discussion of the trnsporttion-relted ir qulity concerns in the project re nd summry of ny crbon monoxide nlysis performed, nd the CAA requires trnsporttion conformity demonstrtion with ny Stte Implementtion Pln (SIP) for ny EPA criteri pollutnt in non-ttinment or mintennce res. Loudoun County is locted in n EPA designted non-ttinment re for the 8-hour ozone stndrd (997 nd 2008 stndrds) nd the 997 nnul fine prticulte mtter (PM2.5) stndrd. The re is designted s ttinment for ll other NAAQS. 3 Project Description The Virgini Deprtment of Trnsporttion (VDOT), in coopertion with the Federl Highwy Administrtion (FHWA), is proposing to construct limited-ccess rodwy to the west of the Wshington Dulles Interntionl Airport in Loudoun County, VA. The project tem is evluting vrious proposed study Alterntives tht would extend from the interchnge of the plnned Tri-County Prkwy nd Lee-Jckson Memoril Highwy (US Route 50) to the existing intersection of Old Cox Rod (VA Route 606) nd Arcol Rod (VA Route 842) where future irport connector rods nd n extension of the Loudon County Prkwy re nticipted to converge. Figure depicts the project study re. 3. Alterntive ; No-Build Alterntive Consistent with the requirements of the NEPA nd relted FHWA guidelines, full considertion is given to the environmentl consequences of tking no ction to meet future trvel demnd (hereinfter referred to s the No-Build Alterntive ). The No-Build Alterntive serves s benchmrk for comprison to the proposed project lterntives by providing bseline condition with which to compre the improvements nd consequences ssocited with ech of the Build Alterntives. The No-Build Alterntive would include ll plnned nd progrmmed trnsporttion improvements in the study re tht hve been pproved nd dopted for implementtion by 2040, s identified in the most recent Ntionl Cpitl Region s Finncilly Constrined Long-Rnge Pln (CLRP). Under the No-Build Alterntive, no dditionl rodwy infrstructure bove nd beyond the CLRP projects would be relized to the west of the irport. The No-Build Alterntive would not stisfy the identified needs of the project. 2

7 Air Qulity Technicl Report Dulles Air Crgo, Pssenger nd Metro Access Highwy Februry 25, 204 VDOT Project No. R , P0 Figure. Study Are 3.2 Alterntive 2 Alterntive 2 would originte t US Route 50, pproximtely 2.2 miles west of its existing intersection with the Loudoun County Prkwy (Route 607), in the loction where the Tri-County Prkwy (VA Route 4) interchnge is plnned, s depicted in Figure 2. Alterntive 2 would connect to the proposed interchnge llowing for ll movements to nd from US Route 50 nd the proposed Tri-County Prkwy (VA Route 4). From US Route 50, the proposed lterntive would extend pproximtely one-mile northest before turning due est south of Evergreen Mills Rod (VA Route 62). The lignment would continue est for pproximtely.7 miles, with n overpss t Belmont Ridge Rod (VA Route 659) nd Evergreen Mills Rod (VA Route 62) until intersecting with existing Old Ox Rod (VA Route 606) / Loudoun County Prkwy. Proposed Alterntive 2 would be limited ccess highwy, specificlly, with no direct ccess to djoining properties. Connections with rteril rodwys would be provided vi US Route 50, Tri-County Prkwy, Old Ox Rod (VA Route 606), plnned extension of Loudoun County Prkwy (VA Route 607) nd the future irport connector rods. 3

8 Air Qulity Technicl Report Dulles Air Crgo, Pssenger nd Metro Access Highwy Februry 25, 204 VDOT Project No. R , P0 Figure 2 Figure 2. No-Build Alterntives nd Study Corridor As shown in the typicl section (See Figure 3) for Alterntive 2, the proposed build option would consist of four-lne divided principl rteril with design speed of 60 miles per hour. Figure 3. Alterntive 2 Typicl Rodwy Section 4

9 Air Qulity Technicl Report Dulles Air Crgo, Pssenger nd Metro Access Highwy Februry 25, 204 VDOT Project No. R , P0 3.3 Alterntive 3 Alterntive 3 consists of mking improvements long existing US Route 50 nd Old Ox Rod (VA Route 606) from the future US Route 50 interchnge t Tri-County Prkwy to proposed full-ccess interchnge with Old Ox Rod (VA Route 606), the plnned Loudoun County Prkwy (VA Route 607) extension, nd future IAD connector rods. Within the Loction Study Corridor for Alterntive 3, three potentil improvements, described below, were studied independently for trffic nd ir qulity impcts Alterntive 3A US Route 50 Elevted Alterntive 3A (Figure 4) would be 4-lne divided limited ccess principl rteril, on n eril structure within the medin of US Route 50. Upon returning to grde prllel to Loudoun County Prkwy, Alterntive 3A would run prllel to Loudoun County Prkwy s seprted 4-lne divided principl rteril but t-grde insted of elevted. Alterntive 3A would originte t US Route 50 nd the plnned Tri-County Prkwy interchnge nd provide full connections to Tri-County Prkwy (VA Route 4). Proposed Alterntive 3A would provide ccess to US Route 50 westbound nd from US Route 50 estbound only. From the interchnge t Tri-County Prkwy (VA Route 4), Alterntive 3A would follow long the US Route 50 lignment in n elevted section, within the rodwy medin. At the future interchnge with Loudoun County Prkwy, the rodwy would trvel north over the Loudoun County Prkwy nd return to grde on the est side of Old Ox Rod (VA 606) / Loudoun County Prkwy, on Dulles Airport property. Alterntive 3A would provide connection to US Route 50 estbound nd from US Route 50 westbound t this future interchnge. From there, the fcility would extend prllel to Old Ox Rod (VA Route 606) / Loudoun County Prkwy pproximtely.7 miles to the future irport connector rods. Figure 4. Alterntive 3A Typicl Rodwy Section 5

10 Air Qulity Technicl Report Dulles Air Crgo, Pssenger nd Metro Access Highwy Februry 25, 204 VDOT Project No. R , P Alterntive 3B Alterntive 3B (Figure 5) would originte t the plnned full-ccess interchnge of US Route 50 nd the Tri-County Prkwy (VA Route 4). To meet Loudoun County s Countywide Trnsporttion Pln (CTP) (Loudoun County, 202), US Route 50 is proposed to be widened from four (4) lnes to six (6) lnes from the plnned interchnge of US Route 50 nd Tri-County Prkwy (VA Route 4) to Gum Springs Rod (VA Route 659). At-grde ccess to ll properties would be closed long US Route 50 from Tri-County Prkwy to Loudoun County Prkwy to meet the limited ccess requirements. Access to properties to the south would be provided from Tll Cedrs Prkwy. Access to properties to the north would be provided from prllel frontge rod ccessed from Gum Springs Rod (VA Route 659). A full ccess interchnge t Gum Springs Rod (VA Route 659) nd US Route 50 would lso be provided, in order to conform to Loudoun County s dopted CTP. A full ccess interchnge would be provided t Old Ox Rod (VA 606) / Loudoun County Prkwy nd US Route 50 where Alterntive 3B would follow Old Ox Rod (VA Route 606) / Loudoun County Prkwy to the north. Under Alterntive 3B, Old Ox Rod (VA Route 606) / Loudoun County Prkwy would be upgrded to n eight (8) lne limited ccess fcility to mtch the Loudoun County CTP designtion of the fcility s freewy. The Loudoun County CTP shows t-grde intersections t proposed Glscock Boulevrd, Evergreen Mills Rd (VA Route 62) nd Arcol Boulevrd (VA Route 842) with the proposed freewy fcility. Alterntive 3B ssumes frontge rod will be provided within the proposed corridor long Old Ox Rod (VA Route 606) / Loudoun County Prkwy in the southbound direction to provide limited ccess to nd from Evergreen Mills Rod (VA Route 62). The frontge rod is nticipted to be for the southbound direction only. Alterntive 3B would terminte s full-ccess interchnge with Old Ox Rod (VA Route 606), the plnned Loudoun County Prkwy (VA Route 607) extension, nd future irport connector rods. This proposed lterntive would be six (6) lne limited ccess fcility long US Route 50 nd n eight (8) lne limited ccess highwy long Old Ox Rod (VA Route 606) / Loudoun County Prkwy. Figure 5. Alterntive 3B Typicl Rodwy Section 6

11 Air Qulity Technicl Report Dulles Air Crgo, Pssenger nd Metro Access Highwy Februry 25, 204 VDOT Project No. R , P Alterntive 3C On July 26, 203, t the request of the Loudoun County Bord of Supervisors following the Drft EA nd Loction Study Public Hering, VDOT greed to incorporte n dditionl modifiction to the Alterntive 3 Loction Study Corridor for evlution in the Revised EA. This modified scenrio, Alterntive 3C (Figure 6 nd Figure 7), would originte t the plnned fullccess interchnge of the US Route 50 nd the Bi-County Prkwy (VA Route 4) nd extend long US Route 50 to n interchnge t VA Route 606/Loudoun County Prkwy. At the estern terminus, irport ccess would be provided into the southwest corner of IAD, where MWAA hs greed their irport plns would be updted s necessry to reflect link to the public rodwy network. Under Alterntive 3C, ccess to nd from the irport would be provided from both directions of US Route 50 nd both directions of VA Route 606/Loudoun County Prkwy. This proposed modifiction long US Route 50 would consist of six through lnes (three in ech direction) two uxiliry lnes in opposite directions, nd two dedicted lnes for trffic in nd out of IAD). VA Route 606 will be widened to six lnes between the interchnge with US Route 50 nd its intersection with Evergreen Mills Rod. An dditionl frontge rod would be included on the north side of US Route 50 in order to mintin ccess for residents nd businesses long this corridor. Figure 6. Alterntive 3C Typicl Rodwy Section 7

12 Air Qulity Technicl Report Dulles Air Crgo, Pssenger nd Metro Access Highwy Februry 25, 204 VDOT Project No. R , P0 Figure 7. Alterntive 3C Typicl Rodwy Section 4 Trffic Summry The trffic nlysis for the project ws conducted by Whitmn, Requrdt & Assocites, LLP (WRA) for the 202 bse yer, nticipted opening/interim yer 2025 nd the 2040 design yer. For the ir qulity nlysis, the relevnt trffic components utilized from the trffic study were the level of service (LOS), verge nnul dily trffic (AADT), pek-hourly AADT, congested speeds, turning movements, rodwy grde nd signl timing dt for ech Alterntive. The trffic study consisted of evluting the five Alterntives to llevite trffic congestion nd ddress rodwy deficiencies within the study re. Ech of the Alterntives vried in terms of signlized intersections nd proposed interchnges. The five Alterntives re described in more detil bove, in Section 3. In totl, combintion of seven intersections/interchnges ws studied in the trffic nlysis. 5 Existing Conditions To chrcterize the existing ir qulity conditions of the Loudoun County re, review of the Virgini Air Qulity Dt Reports prepred by the Virgini Deprtment of Environmentl Qulity (VDEQ) Office of Air Qulity Monitoring ws completed. The nlysis focused on regulted ir pollutnts contined in the NAAQS; including sulfur dioxide (SO 2 ), crbon monoxide (CO), nitrogen dioxide (NO 2 ), ozone (O 3 ), nd prticulte mtter (PM 0 nd PM 2.5 ). The results show tht the EPA designted Loudoun County s non-ttinment for the 8-hour ozone (997 nd 2008) stndrd nd 997 nnul fine prticulte mtter (PM 2.5 ) stndrd. The re is designted s ttinment for ll other stndrds. 6 Meteorology Climte The study re within Loudoun County is locted in Northern Virgini on the western side of IAD nd pproximtely 25 miles to the west-northwest of Wshington, D.C. Winters re mild with limited snowfll nd summers re hot nd humid. The verge nnul temperture for the Dulles re is 55 F, with winter tempertures verging 35 F nd summer tempertures verging 75 F. The re verges 45 inches of rinfll nnully nd receives up to 22 inches of snow on verge. 7 Regultory Stndrds The ir qulity nlysis ddressed the EPA NAAQS, Mobile Source Air Toxics (MSAT) under the NEPA, nd the Trnsporttion Conformity Rule s required by the Clen Air Act. 8

13 Air Qulity Technicl Report Dulles Air Crgo, Pssenger nd Metro Access Highwy Februry 25, 204 VDOT Project No. R , P0 7. Ntionl Ambient Air Qulity Stndrds Pursunt to the Federl Clen Air Act of 970 (CAA), the EPA estblished Ntionl Ambient Air Qulity Stndrds (NAAQS) for mjor pollutnts known s criteri pollutnts. Currently, the EPA regultes six criteri pollutnts: ozone (O 3 ), crbon monoxide (CO), nitrogen dioxide (NO 2 ), sulfur dioxide (SO 2 ), prticulte mtter, nd led (Pb). Prticulte mtter (PM) is divided into two prticle size ctegories: prticles with dimeter less thn 0 micrometers (PM 0 ) nd those with dimeter of less thn 2.5 micrometers (PM 2.5 ). Tble shows the primry nd secondry NAAQS for the criteri pollutnts. The NAAQS re two-tiered. The first tier (primry) is intended to protect public helth; the second tier (secondry) is intended to protect public welfre nd prevent further degrdtion of the environment. Section 76(c) of the CAA requires Federl gencies to ssure tht ll of their ctions conform to pplicble implementtion plns for chieving nd mintining the NAAQS. Federl ctions must not cuse or contribute to ny new violtion of ny stndrd, increse the frequency or severity of ny existing violtion, or dely timely ttinment of ny stndrd. Tble. Ntionl Ambient Air Qulity Stndrds Pollutnt Averging Time Primry Stndrds [,2] Secondry Stndrds [,3] CO 8- hour 9 ppm (0 mg/m 3 ) None - hour 35 ppm (40 mg/m 3 ) None Led [4] Rolling 3-Month Averge [5] 0.5 µg/m 3 Sme s Primry NO 2 Annul Arithmetic Men ppm (00 µg/m 3 ) Sme s Primry -hour 0.00 ppm [6] None PM 0 Annul Arithmetic Men None None 24-hour 50 µg/m 3 Sme s Primry PM 2.5 Annul Arithmetic Men 2 µg/m 3,9 5 µg/m 3 24-hour 35 µg/m 3 Sme s Primry O 3 8-hour (2008 stndrd) ppm Sme s Primry 8-hour (997 stndrd) 0.08 ppm Sme s Primry -hour 0.2 ppm [7] Sme s Primry SO 2 -hour 75 ppb [8] None 3-hour None 0.5 ppm Notes:. Ntionl stndrds (other thn ozone, prticulte mtter, nd those bsed on nnul verges) re not to be exceeded more thn once per yer. The ozone stndrd is ttined when the fourth highest 8-hour concentrtion in yer, verged over three yers, is equl to or is less thn the stndrd. For PM 0, the 24-hour stndrd is ttined when the expected number of dys per clendr yer with 24-hour verge concentrtion bove 50 ug/m 3 is equl to or is less thn one. For PM 2.5, the 24-hour stndrd is ttined when 98% of the dily concentrtions, verged over three yers, re equl to or re less thn the stndrd. 2. Primry Stndrds: Levels necessry to protect public helth with n dequte mrgin of sfety. 3. Secondry Stndrds: Levels necessry to protect the public from ny known or nticipted dverse effects. 4. Led is ctegorized s toxic ir contminnt with no threshold exposure level for dverse helth effects determined. 5. Ntionl led stndrd, rolling three-month verge: finl rule signed October 5, To ttin this stndrd, the 3-yer verge of the 98th percentile of the dily mximum -hour verge t ech monitor within n re must not exceed 0.00 ppm (effective Jnury 22, 200). 7. EPA revoked the -hour ozone stndrd in ll res; however, some res hve continuing obligtions under tht stndrd. 8. Finl rule signed June 2, 200. To ttin this stndrd, the 3-yer verge of the 99 th percentile of the dily mximum - hour verge t ech monitor within n re must not exceed 75 ppb. 9. EPA updted the NAAQS for PM 2.5 to strengthen the primry nnul stndrd to 2 ug/m 3. The stndrds in Tble pply to the concentrtion of pollutnt in outdoor mbient ir. If the ir qulity in geogrphic re is equl to or is better thn the ntionl stndrd, it is clled n ttinment re. Ares where ir qulity does not meet the ntionl stndrd re clled non-ttinment res. Once the ir qulity in non-ttinment re improves to the point where it meets the stndrds nd the dditionl redesigntion requirements in the CAA [Section 07(d) (3)(E)], EPA redesigntes the re s mintennce re. 9

14 Air Qulity Technicl Report Dulles Air Crgo, Pssenger nd Metro Access Highwy Februry 25, 204 VDOT Project No. R , P0 The Clen Air Act Amendments (CAAA) of 990 requires sttes to designte the sttus of ll res within their borders s being in or out of complince with the NAAQS. The CAAA further defines nonttinment res for ozone bsed on the severity of the violtion s mrginl, moderte, serious, severe, nd extreme. In n effort to further improve the ntion s ir qulity, the EPA hs clssified dditionl res s ttinment/non-ttinment for the hour ozone stndrd. The project is locted in n re tht ws designted s being in mrginl non-ttinment under the hour ozone stndrd. Ech stte is required to prepre stte implementtion pln (SIP) tht outlines mesures the region will implement to ttin the pplicble ir qulity stndrd in non-ttinment res, nd to mintin complince with the pplicble ir qulity stndrd in mintennce res. 7.2 Mobile Source Air Toxics In December of 202, FHWA issued the Interim Guidnce Updte on Mobile Source Air Toxic Anlysis in NEPA. The updte reflects the recent implementtion of the EPA MOVES emission model for estimting MSAT emissions from mobiles sources long with updting the scientific reserch in the MSAT ren. The EPA identified seven compounds with significnt contributions from mobile sources tht re mong the ntionl nd regionl-scle cncer drivers from their 999 Ntionl Air Toxics Assessment (NATA). The seven compounds identified were crolein, benzene,,3-butdiene, diesel prticulte mtter plus diesel exhust orgnic gses, formldehyde, nphthlene, nd polycyclic orgnic mtter (POM). While FHWA considers these the priority mobile source ir toxics, the list is subject to chnge nd my be djusted in considertion of future EPA rules. The FHWA guidnce developed tiered pproch for ssessing MSATs in NEPA documents nd identified three levels of nlysis. The three levels identified were for projects with no meningful MSAT effects, low potentil MSAT effects, nd high potentil MSAT effects. The FHWA guidnce defines the levels of nlysis for ech type of MSAT effect: No nlysis for projects with no potentil for meningful MSAT effects; A qulittive nlysis for projects with low potentil MSAT effects; nd A quntittive nlysis for projects with high potentil MSAT effects. The study Alterntives were evluted ginst ech threshold criteri in order to determine the type of MSAT nlysis required to stisfy NEPA. 7.3 Trnsporttion Conformity As discussed bove, Loudoun County is locted in n ttinment re for ll pollutnts s designted by the EPA except for the 997 nd hour ozone stndrds nd the 997 nnul PM 2.5 stndrd for which the re is designted s non-ttinment. The stte of Virgini hs prepred SIP tht outlines the control mesures tht will be implemented to chieve complince nd mintin the ozone nd PM 2.5 NAAQS, respectively. The EPA promulgted the Trnsporttion Conformity Rule (40 CFR Prts 5 nd 93) concerning pplicbility, procedures, nd criteri tht trnsporttion gencies must use in nlyzing nd determining conformity of trnsporttion projects. The Trnsporttion Conformity Rule pplies to federl funded trnsporttion projects in certin res tht hve violted one or more of the NAAQS in EPA designted non-ttinment or mintennce res (40 CFR 93.02(b)). 0

15 Air Qulity Technicl Report Dulles Air Crgo, Pssenger nd Metro Access Highwy Februry 25, 204 VDOT Project No. R , P0 In Mrch of 2006, EPA nd FHWA issued joint guidnce for conducting hot-spot nlysis for prticulte mtter. The guidnce pplies to projects within mintennce or non-ttinment re for PM 2.5 nd outlines the criteri for determining whether project is considered to be one of ir qulity concern. In December 200, EPA issued updted modeling guidnce 2 for performing quntittive nlyses of PM 2.5 nd PM 0 emissions for conforming with the PM 2.5 NAAQS. This guidnce pertins to federlfunded or pproved trnsporttion projects tht re deemed to be projects of ir qulity concern tht re locted in PM 2.5 non-ttinment nd mintennce res. The federl conformity rule requires tht conforming trnsporttion pln nd progrm be in plce t the time of the project pprovl (40 CFR 93.4), nd for the project to be included in the conforming pln nd progrm (40 CFR 93.5). On Februry 20, 203 the Ntionl Cpitl Region Trnsporttion Plnning Bord (TPB) greed to include the Dulles Air Crgo, Pssenger, nd Metro Access Highwy build nd no-build lterntives for regionl ir qulity conformity testing. In Mrch 204, VDOT will formlly mke recommendtion on preferred Alterntive to the TPB for inclusion in the 204 Ntionl Cpitl Region s Finncilly Constrined Long-Rnge Pln (CLRP) which includes projected trnsit nd trffic, demogrphics, nd ir qulity conditions through the 2040 horizon yer. 8 Project Assessment An ir qulity project level nlysis ws conducted for crbon monoxide (CO), prticulte mtter (PM) nd Mobile Source Air Toxics (MSATs). The methodologies nd ssumptions for ddressing the type of nlysis for ech pollutnt is discussed below nd is consistent with ll FHWA nd EPA regultions nd guidnce, s well s the VDOT Consultnt Guide on Air Qulity Project-Level Anlysis (My 2009) Crbon Monoxide (CO) Anlysis On Februry 27, 2009, the FHWA nd VDOT finlized n updted memorndum of understnding (MOU) ddressing NEPA requirements for project-level CO ir qulity nlyses. Under this greement, project-level ir qulity (hot-spot) nlyses re conducted for CO for projects tht meet trffic nd relted criteri s specified in the greement. A hot-spot nlysis for CO is required for this nlysis s the expected trffic volumes will exceed the qulittive nlysis threshold criteri specified in the MOU. The ir qulity study utilizes the trffic ssessment conducted by the design tem for the 202 bse yer, 2025 interim yer nd the 2040 design yer conditions. Emissions of CO were estimted using the EPA Motor Vehicle Emissions Simultor (MOVES) model. Ambient concentrtions t sensitive receptor loctions were estimted using the EPA CAL3QHC dispersion model, nd the results were dded to pproprite bckground concentrtions for comprison to the CO NAAQS to determine complince. 8.. Methodology The microscle nlysis typiclly exmines worst-cse ground-level CO impcts due to trffic flow in the immedite vicinity of project intersection/interchnge. CO is used in microscle studies to indicte rodwy pollutnt levels s it is the most bundnt pollutnt emitted by motor vehicles nd cn result in so-clled hot-spot (i.e., high concentrtion) loctions round congested intersections. The NAAQS Trnsporttion Conformity Guidnce for Qulittive Hot-Spot Anlyses in PM2.5 nd PM0 Nonttinment nd Mintennce Ares (Mrch 2006). 2 Trnsporttion Conformity Guidnce for Quntittive Hot-Spot Anlyses in PM 2.5 nd PM 0 Nonttinment nd Mintennce Ares, US EPA, December Consultnt Guide Air Qulity Project-Level Anlysis, Revision 8: VDOT Environmentl Division, Air Section, My 2009.

16 Air Qulity Technicl Report Dulles Air Crgo, Pssenger nd Metro Access Highwy Februry 25, 204 VDOT Project No. R , P0 were developed by the EPA to protect humn helth ginst dverse helth effects with mrgin of sfety. These stndrds do not llow mbient CO concentrtions to exceed 35 prts per million ( ppm ) for -hour verging period nd 9 ppm for n 8-hour verging period, more thn once per yer t ny loction. The widespred use of dvnced ctlytic technologies on lte-model vehicles hs significntly reduced the occurrences of CO hotspots in recent yers. Air qulity models (computer simultion progrms) re typiclly used to predict worst-cse CO levels for both existing nd future conditions to evlute complince of proposed rodwys with the CO NAAQS. The microscle nlysis ws conducted using the ltest versions of the EPA MOVES (MOVES200b) nd CAL3QHC models to estimte worst-cse CO concentrtions t individul receptor (i.e. receiver) loctions. CAL3QHC modeling results for ech condition were then dded to the pproprite bckground CO concentrtions to determine worst-cse ir qulity impcts for ech Study Alterntive. These vlues were then compred to the -hour nd 8-hour CO NAAQS to determine complince Intersections Studied As discussed bove, pek-hour volume nd LOS nlysis ws completed for the existing, interim nd design yer for ech Alterntive. Bsed on the trffic nlysis, quntittive hot-spot ir qulity nlysis ws required for CO since trffic volumes re predicted to exceed the threshold criteri specified in the 2009 VDOT-FHWA Project-Level Crbon Monoxide Air Qulity Studies Agreement. An nlysis of the pek-hour Build Alterntive volumes, LOS, nd dely times were evluted to estblish the worst-cse intersection/interchnges nd Alterntive conditions for inclusion in the CO hot-spot modeling nlysis. Tble 2 provides the totl AM nd PM pek-hour trffic volumes long with the LOS for ech signlized intersection nd/or interchnge within the project corridor while Tble 3 provides the projected dely times. The tbles summrize the trffic results for the existing (202), no-build, nd Build Alterntives for 2025 nd

17 Air Qulity Technicl Report Dulles Air Crgo, Pssenger nd Metro Access Highwy Februry 25, 204 VDOT Project No. R , P0 Tble 2. Estimted LOS nd Pek-Hourly Trffic Volumes t the Intersections/Interchnges for the 2025 nd 2040 Alterntive Conditions Intersection Pek Existing Volumes Existing LOS 2025 No Build 2025 NB Volumes LOS 2025 Build Alt-2 Volumes 2025 Build Alt-2 LOS 2025 Build Alt-3A Volumes 2025 Build Alt-3A LOS 2025 Build Alt-3B Volumes 2025 Build Alt-3B LOS 2025 Build Alt-3C Volumes 2025 Build Alt-3C LOS 2040 No Build 2040 NB Volumes LOS 2040 Build Alt-2 Volumes 2040 Build Alt-2 LOS 2040 Build Alt-3A Volumes 2040 Build Alt-3A LOS 2040 Build Alt-3B Volumes 2040 Build 2040 Build Alt-3C 2040 Build Alt-3B LOS Volumes Alt-3C LOS Intersection Loudon County Old Ox Rod t Dulles Connector Rod AM This intersection only exists in future Alterntives 3584 C 3656 C Intersection becomes n Interchnge, All Rmps operte t Cor Better becomes n Interchnge, All Rmps operte t C 4000 B 4552 F 400 D Intersection becomes n Interchnge, All Rmps operte t C or Intersection becomes n Interchnge, All Rmps operte t Cor Better 4727 D PM 4480 D 4570 D (See Note ) or Better (See Note 4820 C 5690 F 5000 D Better (See Note ) (See Note ) 6476 E ) Signlized Rmps Signlized Rmps Signlized Rmps Only Signlized Rmps Signlized RmpsOnly Signlized Rmps Signlized Rmps Only Signlized Rmps Only Signlized Rmps Only LoudounCountyPrkwy t Only Exist Under Only Exist Under Exist Under Alterntive - Only Exist Under Exist Under Alterntive - Only Exist Under Exist Under Alterntive - Exist Under Alterntive - Exist Under Alterntive EB Dulles Connector Rmps AM Alterntive -2 Alterntive C Alterntive -2 D 2 Alterntive PM 3263 B 3600 C Totl Signlized Rmps Signlized Rmps Signlized Rmps Only Signlized Rmps Signlized RmpsOnly Signlized Rmps Signlized Rmps Only Signlized Rmps Only Signlized Rmps Only LoudounCountyPrkwy t Only Exist Under Only Exist Under Exist Under Alterntive - Only Exist Under Exist Under Alterntive - Only Exist Under Exist Under Alterntive - Exist Under Alterntive - Exist Under Alterntive WB Dulles Connector Rmps AM Alterntive -2 Alterntive B Alterntive -2 C 2 Alterntive PM 3263 B 3600 C Totl Northstr Boulevrd AM Interchnge Does not exist under the Existing Conditon PM Signlized Rmps Signlized Rmps Signlized Rmps Only Signlized Rmps US SB Northstr Boulevrd AM Only Exist Under Alterntive -2 Only Exist Under Alterntive A Exist Under Alterntive - 2 Only Exist Under 2345 Alterntive -2 A PM 285 A 2400 A Totl Signlized Rmps Signlized Rmps Signlized Rmps Only Signlized Rmps Signlized RmpsOnly Signlized Rmps US NB Northstr Boulevrd AM Only Exist Under Alterntive -2 Only Exist Under Alterntive B Exist Under Alterntive - 2 Only Exist Under Alterntive -2 Exist Under Alterntive - 2 Only Exist Under Alterntive B PM 958 A 250 A Totl Interchnge AllRmps Interchnge AllRmps operte t Cor Better operte t Cor Better US Loudoun County Prkwy AM 4485 D Totl PM D Interchnge All Rmps operte t C or Better Interchnge All Rmps operte t C or Better Thisn Interchnge, ll rmps operte t LOS C or better Interchnge AllRmps operte t Cor Better Interchnge All Rmps operte t C or Better Interchnge All Rmps operte t C or Better This is n Interchnge. All Rmpsoperte t LOSCor Better. Signlized RmpsOnly Exist Under Alterntive - 2 This is n interchnge. All rmpsoperte t LOS C or Better Interchnge All Rmps operte t C or Better Signlized Rmps Only Exist Under Alterntive -2 Interchnge All Rmps operte t C or Better This is n Interchnge, ll rmps operte t LOSCor better Interchnge All Rmps operte t C or Better Interchnge AllRmps operte t Cor Better Signlized Rmps Only Exist Under Alterntive - 2 Signlized Rmps Only Exist Under Alterntive - 2 Interchnge AllRmps operte t Cor Better Interchnge AllRmps operte t Cor Better Signlized Rmps Only Exist Under Alterntive - 2 Signlized Rmps Only Exist Under Alterntive - 2 Interchnge AllRmps operte t Cor Better Interchnge All Rmps operte t C or Better Signlized Rmps Only Exist Under Alterntive -2 Signlized Rmps Only Exist Under Alterntive -2 Interchnge All Rmps operte t C or Better Intersection Intersection becomes n Intersection becomes becomes n Interchnge AllRmps n Interchnge All US Gum Spring Rod AM 2445 F 3955 E 3709 E 3767 D Interchnge All Intersection becomes n 4460 E 3900 E 439 D operte t Cor Better Rmps operte t C or PM 360 F 569 D 464 D 5374 D Rmps operte t C Interchnge All Rmps 6382 E 4950 E 5996 E Better Totl or Better operte t Cor Better Signlized Rmps Signlized Rmps Signlized Rmps Only Signlized Rmps Only Signlized Rmps Signlized Rmps Only Signlized Rmps Only Gum Spring EB Route Only Exist Under Only Exist Under Exist Under Alterntive - Exist Under Alterntive - Only Exist Under Exist Under Alterntive - Exist Under Alterntive - 50 Rmps AM Alterntive -3B Alterntive B A B A 327 3B A Alterntive -3B 3B 3B 2877 A PM 603 A 236 A 3076 A 2507 A Totl Signlized Rmps Signlized Rmps Signlized Rmps Only Signlized Rmps Only Signlized Rmps Signlized Rmps Only Signlized Rmps Only Gum Spring WB Route Only Exist Under Only Exist Under Exist Under Alterntive - Exist Under Alterntive - Only Exist Under Exist Under Alterntive - Exist Under Alterntive - 50 Rmps AM Alterntive -3B Alterntive 572-3B B 532 3B B 840 3B B Alterntive -3B 3B 3B 75 B PM 3092 C 205 C 2457 C 2353 C Totl Evergreen Mills Belmont Ridge Rod/Brirfield Lne AM 840 F 2645 F 285 F 2505 F 980 F 2440 F 2965 F 2245 F 280 F 2063 F 2723 F PM 92 F 2745 F 2255 F 2560 F 2253 F 2595 F 2970 F 2295 F 290 F 2289 F 2890 F Totl Loudon County Evergreen Mills Rod AM 2520 D 4278 B 435 B 4598 D Intersection is removed, ccess 4527 B 559 D 470 B 5043 D Intersection isremoved, ccess provided vi 520 B PM 290 C 5385 F 4760 E 5803 F provided vi rmps 5789 D 6495 F 4790 E 6366 F rmpstoor fromsb 726 F Totl to or from SB LCP LCP Note : Site # isnintersectiontht doesnot exist currently. Withthe extension of LoudounCountyPrkwyinthe future thisintersection will exist. The DullesConnector rod joinsthisintersectioninalterntive 2 to form 4thleg, nd in Alterntives3A, 3B, nd3cthisintersection becomes prt of the interchnge. 3

18 Air Qulity Technicl Report Dulles Air Crgo, Pssenger nd Metro Access Highwy Februry 25, 204 VDOT Project No. R , P0 Site Intersection AM A Tble 3. Estimted LOS nd Projected Dely Times t the Intersections for the 2025 nd 2040 Alterntive Conditions 2025 Alterntive Alterntive 3A 2025 Alterntive 3B Delys (sec) PM Delys (sec) AM Delys (sec) PM Delys (sec) AM Delys (sec) PM Delys (sec) Loudoun County Prkwy t EB Signlized Rmps Only Signlized Rmps Only Exist Dulles Connector Rmps C 25.2 B 8.6 Exist Under Alterntive-2 D 36.5 Under C Alterntive AM 2025 Alterntive 3C 2040 Alterntive Alterntive 3A 2040 Alterntive 3B Delys (sec) PM Delys (sec) AM Delys (sec) PM Delys (sec) AM Delys (sec) PM Delys (sec) AM Delys (sec) PM Delys (sec) AM 2040 Alterntive 3C Delys (sec) PM Delys (sec) Intersection becomes n Intersection becomes n Intersection becomes n Intersection becomes n Loudon County Old Ox Rod t Dulles Connector Rod C 33.6 D 35. interchnge, ll rmps operte t C or better (See Note ) interchnge, ll rmps operte t C or better (See Note ) B 5.3 C 30.3 D 46 D 45.2 interchnge, ll rmps operte t C or better (See Note ) interchnge, ll rmps operte t C or better (See Note ) D 8.5 E 6.6 Signlized Rmps Only Exist Under Alterntive-2 Signlized Rmps Only Exist Under Alterntive-2 Signlized Rmps Only Exist Under Alterntive-2 Loudoun County Prkwy t WB Signlized Rmps Only Signlized Rmps Only Exist B Dulles Connector Rmps B.9 B 8.6 Exist Under Alterntive-2 C 20. Under C Alterntive This is n Interchnge, ll This is n Interchnge, ll This is n Interchnge, ll rmps operte t LOS C or rmps operte t LOS C or rmps operte t LOS C or 3 US Northstr Boulevrd better better better Signlized Rmps Only Exist Under Alterntive-2 This is n Interchnge, ll rmps operte t LOS C or better Signlized Rmps Only Exist Under Alterntive-2 This is n Interchnge, ll rmps operte t LOS C or better Signlized Rmps Only Exist Under Alterntive-2 This is n Interchnge, ll rmps operte t LOS C or better Signlized Rmps Only Exist Under Alterntive-2 This is n Interchnge, ll rmps operte t LOS C or better Signlized Rmps Only Signlized Rmps Only Exist 3A US SB Northstr Boulevrd A 6.3 A 4.9 Exist Under Alterntive-2 A 6.4 Under A Alterntive Signlized Rmps Only Exist Under Alterntive-2 Signlized Rmps Only Exist Under Alterntive-2 Signlized Rmps Only Exist Under Alterntive-2 Signlized Rmps Only Exist Under Alterntive-2 Signlized Rmps Only Signlized Rmps Only Exist 3B US NB Northstr Boulevrd B.9 A 6.5 Exist Under Alterntive-2 B 4.5 Under A Alterntive Signlized Rmps Only Exist Under Alterntive-2 Signlized Rmps Only Exist Under Alterntive-2 Signlized Rmps Only Exist Under Alterntive-2 Signlized Rmps Only Exist Under Alterntive-2 2 US Loudoun County Prkwy This is n Interchnge, ll rmps operte t LOS C or This is n Interchnge, ll rmps operte t LOS C or This is n Interchnge, ll rmps operte t LOS C or This is n Interchnge, ll rmps operte t LOS C or better This is n Interchnge, ll rmps operte t LOS C or This is n Interchnge, ll rmps operte t LOS C or Intersection becomes n Intersection becomes n Interchnge, All rmps Interchnge, All rmps operte 4 US Gum Spring Rod E 56.4 D 40.3 D 47.4 D 38.7 operte t C or better t C or better E 73.4 E 55. D 54.6 E 57.6 This is n Interchnge, ll rmps operte t LOS C or Intersection becomes n Interchnge, All rmps operte t C or better This is n Interchnge, ll rmps operte t LOS C or Intersection becomes n Interchnge, All rmps operte t C or better 4A Gum Spring EB Route 50 Signlized Rmps Only Signlized Rmps Only Signlized Rmps Only Exist Signlized Rmps Only Exist Rmps Exist under Alterntive 3B Exist under Alterntive 3B A 9.3 A 9 A 8.3 A 5.7 under Alterntive 3B under Alterntive 3B A 8.8 A 4.9 A 0 A 9.6 4B 5 6 Gum Spring WB Route Signlized Rmps Only Signlized Rmps Only Signlized Rmps Only Exist Signlized Rmps Only Exist 50 Rmps Exist under Alterntive 3B Exist under Alterntive 3B B.4 C 22.4 B.2 C 20.9 under Alterntive 3B under Alterntive 3B B 2.7 C 23.4 B 2 C 20. Evergreen Mills Belmont Ridge Rod/Brirfield Lne F 66.9 F 209. F F 25.9 F 58.7 F F 20 F F 72.6 F 26.4 F F 324. F 83.7 F F 28 F Intersection is removed, Intersection is removed, Loudon County ccess provided vi rmps ccess provided vi rmps Evergreen Mills Rod B 20 E 64.4 D 36.3 F 56.8 to or from SB LCP. B 2.6 D 43.7 B 8.9 E 62.6 D 5.7 F 95.8 to or from SB LCP. D 3.6 E.6 Note : Site # is n intersection tht does not exist currently. With the extension of Loudoun County Prkwy in the future this intersection will exist. The Dulles Connector rod joins this intersection in Alterntive 2 to form 4th leg, nd in Alterntives 3A nd 3B this intersection becomes prt of the interchnge. 4

19 Air Qulity Technicl Report Dulles Air Crgo, Pssenger nd Metro Access Highwy Februry 25, 204 VDOT Project No. R , P0 A comprison of the four Build Alterntives for 2025 shows tht there re two intersections which re expected to operte t n LOS of F for both the AM nd PM pek-hourly periods;. Evergreen Mills Rod t Belmont Ridge Rod t Brirfield Lne, nd 2. Loudoun County Prkwy t Evergreen Mills Rod. The highest pek-hourly volumes of the four Build Alterntives re expected to occur under Alterntive 3A t these intersections. US 50 t Gum Spring Rod is lso expected to operte t LOS of D. The worst-cse pek-hourly volumes (e.g in the PM) for this intersection re lso expected to occur under Alterntive 3A. In ddition, the predicted dely times re lso generlly expected to be the highest under Alterntive 3A with mximum dely time rnging from 36 seconds to 302 seconds. A comprison of the Build Alterntives for 2040 shows tht the two highest pek-hour trffic volumes with n LOS of D, E, or F re expected t the following intersections:. Loudoun County Prkwy t Old Ox Rod; nd 2. Loudoun County Prkwy t Evergreen Mills Rod. The highest pek-hourly volumes of the four Build Alterntives re expected to occur under Alterntive 3C t these intersections. It should be noted tht the Loudoun County Prkwy t Old Ox Rod only exists in the interim build nd design condition nd does not exist in the existing condition. The next highest pek-hour trffic volumes with LOS of E or F re expected to occur t the intersection of US 50 t Gum Spring Rod (e.g., 5996 in the PM) nd Evergreen Mills Rod t Belmont Ridge Rod t Brirfield Lne (e.g., 290 in the PM) for Alterntive 3A. The predicted dely times for these intersections nd conditions re generlly expected to be the highest under Alterntive 3A nd Alterntive 3C. These four intersections with the highest pek volumes nd dely times re representtive of where the mximum CO concentrtions re expected to occur where the generl public my hve ccess. The remining intersections within the project corridor re projected to hve lower pek-hour trffic volumes or operte t LOS of D or better for ll other Alterntives which would generlly correlte to lower - hour nd 8-hour pek CO concentrtions. In summry, review of the LOS, pek trffic volumes nd dely time for ech nlysis yer nd the four Build Alterntives determined tht the four worst-cse intersections for inclusion in the CO hot-spot nlysis were:. US 50 t Gum Springs Rod; 2. Evergreen Mills Rod t Belmont Ridge Rod t Brirfield Lne; 3. Loudoun County Prkwy t Evergreen Mills Rod; nd 4. Loudoun County Prkwy t Old Ox Rod. The nlysis lso included evlutions of the worst-cse ffected interchnges from ech Build Alterntive for inclusion in the ir qulity nlysis. Tble 4 provides the predicted trffic volumes t ech interchnge for 2025 nd 2040 conditions. The volumes presented in Tble 4 represent the totl volumes entering nd exiting the interchnge from ll directions. A comprison of the trffic volumes t ech interchnge for ech Build Alterntive shows the highest trffic volumes re expected to occur t the US 50 t Loudoun County Prkwy interchnge for both the 2025 nd 2040 conditions. For the 2025 condition, Alterntive 3A results in the worst-cse volumes of 09,00, while for the 2040 condition, Alterntive 3C results in the worst-cse volumes of 6,450. Therefore, the interchnge t US 50 nd Loudoun County Prkwy ws included in the CO hot-spot nlysis long with the four intersections identified bove since it ws lso determined to be representtive of where mximum CO concentrtions my be expected to occur nd where the generl public my hve ccess. 5

20 Air Qulity Technicl Report Dulles Air Crgo, Pssenger nd Metro Access Highwy Februry 25, 204 VDOT Project No. R , P0 Tble 4. Estimted Trffic Volumes Entering nd Exiting ech Interchnge for the 2025 nd 2040 Alterntive Conditions Interchnge Description 2025 Build- Alt-2 Dily Volumes Totl 2025 Build- Alt-3A Dily Volumes Totl 2025 Build-Alt- 3B Dily Volumes Totl 2025 Build- Alt-3C Dily Volumes Totl 2040 Build- Alt2 Dily Volumes Totl 2040 Build- Alt-3A Dily Volumes Totl 2040 Build- Alt-3B Dily Volumes Totl 2040 Build Alt-3C Dily Volumes Totl Loudoun County Prkwy t Dulles Connector Rmps 47,650 53,600 56,700 55,350 56,850 58,900 66,550 73,00 US 50 t Loudoun County Prkwy 84,800 09,00 0,650 0,250 87,750 2,250,650 6,450 US 50 t Northstr Boulevrd 62,700 49,500 5,50 55,350 68,850 69,350 57,200 63,800 Gum Spring Rod t Route 50 55,950 64,650 8,600 70,050 57,600 63,200 87,800 80,800 Notes: Dily volumes re the sum of trffic entering nd exiting the intersections from ll directions. The trffic nlysis s summrized bove hs demonstrted tht the five intersections/interchnges selected for evlution in the CO hot-spot nlysis hve the worst-cse LOS nd/or highest trffic volumes within the project corridor, nd re representtive of the loctions where pek CO concentrtions would be expected to occur nd where the generl public my hve ccess. It is ssumed tht, if these worst-cse intersections/interchnges re found to hve pek ground level CO concentrtions below the CO NAAQS, then ll other loctions in the study re will lso remin below the CO NAAQS. As per Appendix A, the trffic nlysis results for ech condition used in the ir qulity nlysis cn be mde vilble upon request MOVES Emissions Estimtion CO vehicle emission rtes were estimted using the ltest version of the EPA MOVES (MOVES200b) model which recently replced the MOBILE6.2 emission model. The methodologies nd ssumptions used to run the MOVES model in this nlysis were consistent with the EPA guidnce document Using MOVES in Project Level Crbon Monoxide Anlyses. 4 Vehicle, fuels, nd trffic dt used s input into the MOVES model ws provided by the Metropolitn Wshington Council of Governments (MWCOG) nd the Virgini Deprtment of Environmentl Qulity (VDEQ), consistent with inputs used in the most recent regionl emissions modeling nlysis. Specificlly, fuel nd I/M input dt required s input to the MOVES dtbse were provided by VDEQ for Loudoun County. MOVES ws run utilizing the vehicle popultion nd ge distribution input dt provided by MWCOG since these dtbses hve been ugmented with regionl survey dt nd re specific to the re. MOVES input relies on link-specific dt, therefore, link files were developed for ech studied intersection/interchnge for ech nlysis yer. The link files include dt such s rod type, pek-hourly volumes, link lengths, speed, nd rodwy grde. The rodwy grdes for the existing, no-build nd build intersections were derived using GIS contours. For ny future new interchnge rmps nd rodwys, mximum llowble rodwy grdes were estimted using the VDOT Rod Design Mnul s worst-cse ssumption. The source type hour frctions for ech link were derived from the totl source operting hours for ech vehicle type nd rod type tht were generted from regionl MOVES model run using inputs provided by MWCOG from their most recent conformity finding. Worst-cse meteorologicl dt consistent with the VDOT Consulting Guide for Northern Virgini ws ssumed in RunSpec portion of the MOVES input file. A summry of the MOVES inputs re presented in Tble 5. 4 Environmentl Protection Agency, Using MOVES in Project Level Crbon Monoxide Anlyses. Report Number EPA 420-B December

21 Air Qulity Technicl Report Dulles Air Crgo, Pssenger nd Metro Access Highwy Februry 25, 204 VDOT Project No. R , P0 Tble 5. Summry of MOVES Inputs Prmeter Scle Menu Assumptions Project Domin Min/Mx Temperture 22 F Absolute Humidity 75% Evlution Month Time Spn Geogrphic Bounds Vehicles Equipment Link Files Rodwy Grde/Link Speeds Fuel nd I/M Inputs Vehicle Popultion nd Age Distribution Pollutnts nd Process Pnel Output Pnel Jnury AM Hour= 8AM to 9AM, PM Hour = 5PM to 6PM, Dys=Weekdys Virgini, Loudoun County All Vehicle Types nd Fuel Types Rodwy Specific Provided by WRA Provided by VDEQ Provided by MWCOG CO Running nd CO Crnkcse Grms nd Miles Selected s Units, Popultion nd Distnce trveled Mobile source emissions were clculted bsed on ctul congested speeds t which vehicles trvel through the intersections, while idle emissions re used to represent vehicles queuing. The MOVES model ws used to generte CO emission rtes for input into the CAL3QHC dispersion model for the bse yer (202), interim yer (2025) nd finl design yer (2040) conditions. A smple MOVES input nd output file is provided in Appendix B. A complete set of MOVES input/output files cn be mde vilble upon request CAL3QHC Dispersion Model The ltest version of the CAL3QHC model (04244) 5 ws used to predict worst-cse -hour CO concentrtions from queue nd free-flow links using the FHWA CAL3Interfce 6. The CAL3Interfce is softwre pckge tht incorportes the EPA CAL3QHC dispersion model. The CAL3QHC model incorported defult prmeters per EPA guidnce nd the VDOT Consultnt Guide. The -hour concentrtions from CAL3QHC were scled by fctor of to estimte 8-hour concentrtions. Approprite signl timing dt from the trffic nlysis modeling runs were input into the model for the signlized intersections. Trvel speeds were estimted bsed on field observtions, the trffic nlysis, nd queuing t the intersections. A summry of inputs used in the CAL3Interfce model re shown in Tble 6. 5 User s Guide to CAL3QHC Version 2.0: A Modeling Methodology for Predicting Pollutnt Concentrtions Ner Rodwy Intersections, EPA-454/R (Revised), EPA, September See CAL3Interfce A Grphicl User Interfce for the CALINE3 nd CAL3QHC Highwy Air Qulity Models, Michel Clggett, Ph.D., FHWA Resource Center, EPA guidnce for estimting 8-hour concentrtions from -hour concentrtions. 7

22 Air Qulity Technicl Report Dulles Air Crgo, Pssenger nd Metro Access Highwy Februry 25, 204 VDOT Project No. R , P0 Tble 6. Summry of CAL3QHC Inputs Description Surfce Roughness Coefficient Bckground CO Concentrtions Wind Speed Stbility Clss Mixing Height Wind Direction Vlue 75 Centimeters 2.9 ppm -hour, 2.3 ppm 8-hour (NOVA).0 meter per second Urbn D,000 meters 5 degree increments A smple CAL3QHC input nd output file is provided in Appendix C. A complete set of CAL3QHC files cn be mde vilble upon request Receptors For the modeling nlysis, receptor loctions were plced in the vicinity of the five intersections/interchnges t worst-cse loctions such s sidewlks, property lines, nd prking lots where the public generlly hs ccess. Consistent with EPA modeling guidelines 8, the receptors were locted minimum of 3 meters from the edge of the rodwy nd positioned t height of.8 meters bove the ground. Figure 8 through Figure 5 show the receptor loctions input into CAL3QHC for ech intersection/interchnge. It should be noted tht the modeling for the existing, No-Build nd Build Alterntive conditions t the interchnge of US 50 nd Loudoun County prkwy were conducted using three different sets of rodwy geometry (i.e. links) configurtions nd receptor loctions since this intersection/interchnge design vries for ech condition. The existing condition represents typicl four-wy signlized intersection while the future No-Build conditions incorporte the nticipted design s result of seprte project which chnges the intersection to n interchnge. Alterntive 3A nd 3C represents seprte rodwy design independent of the existing nd No-Build conditions. The receptor loctions for the US 50 nd Loudoun County Prkwy intersection/interchnge re presented in Figure, Figure 2, Figure 3, nd Figure 4 for ech modeled condition. Where pproprite, receptors from the existing condition were lso included in the modeling of the No-Build nd Build Alterntive. Figure 5 shows the receptor loctions for the Loudoun County Prkwy t Old Ox Rod intersection nd ws only evluted for 2025 nd 2040 conditions since the intersection does not exist for Guidelines for Modeling Crbon Monoxide from Rodwy Intersections, EPA-454/R , US EPA,

23 Evergreen Mills Rod Belmont Ridge Rod Pth: G:\PROJECTS\304800_WRA_VDOT_Env\004_Dulles_Airport_Connector\00_Noise\GIS\305080_DullesAC_Air_Qulity_Figure8.mxd Brirfield Lne Dulles Air Crgo, Pssenger, nd Metro Access Highwy Project No. R , P0; UPC No Figure 8 CAL3QHC Receptor Loctions: Evergreen Mills Rod t Belmont Ridge Rod nd Brirfield Lne Feet

24 UV Pth: G:\PROJECTS\304800_WRA_VDOT_Env\004_Dulles_Airport_Connector\00_Noise\GIS\305080_DullesAC_Air_Qulity_Figure9.mxd Gum Springs Rod Lee Jckson memoril Highwy 29 Dulles Air Crgo, Pssenger, nd Metro Access Highwy Project No. R , P0; UPC No Figure 9 CAL3QHC Receptor Loctions: US 50 t Gum Springs Rod Feet

25 Pth: G:\PROJECTS\304800_WRA_VDOT_Env\004_Dulles_Airport_Connector\00_Noise\GIS\305080_DullesAC_Air_Qulity_Figure0.mxd Evergreen Mills Rod Loudoun County Prkwy UV Dulles Air Crgo, Pssenger, nd Metro Access Highwy Project No. R , P0; UPC No Figure 0 CAL3QHC Receptor Loctions: Loudoun County Prkwy t Old Ox Rod Feet

26 Pth: G:\PROJECTS\304800_WRA_VDOT_Env\004_Dulles_Airport_Connector\00_Noise\GIS\305080_DullesAC_Air_Qulity_Figure.mxd UV Dulles Air Crgo, Pssenger, nd Metro Access Highwy Project No. R , P0; UPC No Figure CAL3QHC Receptor Loctions: US 50 t Loudoun County Prkwy Existing Conditions 0 500,000 Feet

27 Pth: G:\PROJECTS\304800_WRA_VDOT_Env\004_Dulles_Airport_Connector\00_Noise\GIS\305080_DullesAC_Air_Qulity_Figure2.mxd UV Dulles Air Crgo, Pssenger, nd Metro Access Highwy Project No. R , P0; UPC No Figure 2 CAL3QHC Receptor Loctions: US 50 t Loudoun County Prkwy No Build Conditions 0,000 2,000 Feet

28 Pth: G:\PROJECTS\304800_WRA_VDOT_Env\004_Dulles_Airport_Connector\00_Noise\GIS\305080_DullesAC_Air_Qulity_Figure3.mxd UV Dulles Air Crgo, Pssenger, nd Metro Access Highwy Project No. R , P0; UPC No Figure 3 CAL3QHC Receptor Loctions: US 50 t Loudoun County Prkwy Alterntive 3A 0,000 2,000 Feet

29 Pth: G:\PROJECTS\304800_WRA_VDOT_Env\004_Dulles_Airport_Connector\00_Noise\GIS\305080_DullesAC_Air_Qulity_Figure4.mxd UV Dulles Air Crgo, Pssenger, nd Metro Access Highwy Project No. R , P0; UPC No Figure 4 CAL3QHC Receptor Loctions: US 50 t Loudoun County Prkwy Alterntive 3C 0,000 2,000 Feet

30 7 Pth: G:\PROJECTS\304800_WRA_VDOT_Env\004_Dulles_Airport_Connector\00_Noise\GIS\305080_DullesAC_Air_Qulity_Figure5.mxd Dulles Air Crgo, Pssenger, nd Metro Access Highwy Project No. R , P0; UPC No Figure 5 CAL3QHC Receptor Loctions: Loudoun County Prkwy t Old Ox Rod Feet