Clark County Department of Aviation 

## IV. Environmental Consequences The potential environmental consequences associated with the Proposed Action and the No Action alternative are discussed in this chapter. The environmental categories evaluated, as specified in FAA Orders 1050.1E [I-1], 5050.4B [I-2], and BLM’s NEPA Handbook H-1790-1, Appendix 5 [I-3], are as follows: x 

### Noise x 

### Compatible land use x 

### Socioeconomic impacts, environmental justice, and children’s environmental health and safety risks x 

### Air quality x 

### Areas of critical environmental concern 1 x 

### Department of Transportation Section 4(f) lands x 

### Historic, architectural, archaeological, and cultural resources x 

### Native American religious concerns 1 x 

### Wilderness 1 x 

### Fish, wildlife, and plants x 

### Federally-listed threatened or endangered species x 

### Invasive, nonnative species 1 x 

### Floodplains and floodways x 

### Water quality x 

### Hazardous materials, pollution prevention, and solid waste x 

### Light emissions x 

### Visual resources 1,2 x 

### Natural resources and energy supply x 

### Secondary (induced) impacts x 

### Construction impacts x 

### Consistency with plans, goals, and policies x 

### Cumulative impacts The following environmental resources are not present within the project area and, therefore, would not be affected by the Proposed Action or the No Action alternative: wetlands, coastal resources, wild and scenic rivers, farmlands, and wild horses and borros 1 

### . 

## 4.1 Noise Potential noise effects associated with the Proposed Action and the No Action were estimated at and within the Overflight Area in accordance with FAA Orders 1050.1E and 5050.4B. The FAA’s INM, Version 7.0 3 

### was used to quantify helicopter noise exposure in close proximity to the Heliport site, at McCarran and along existing or potential flight corridors to determine the potential for adverse noise exposure impacts associated with the Proposed Action. Noise modeling assumptions included:

1 “Critical Elements of the Human Environment”, as listed in Appendix 5 of the BLM’s NEPA Handbook H-1790-1 . In accordance with BLM Instruction Memorandu m No. NV-2005-028, determination of significance for these environmental categories will be prov ided in the agency decision document. All other environmental categories will include the determination of significance in this EA, as required under FAA guidance [I-1, I-2]. 2 Visual resources, as detailed in the BLM’s Visual Resource Management (VRM) 8400 series manuals. 3 See Section 3.5 and Appendix D for a description of the INM. Final EA for a Southern Nevada Regional Heliport IV-1 December 2008 Environmental ConsequencesClark County Department of Aviation
x 

### forecasts and distribution 4 

### of helicopter activity x 

### the types of helicopters (the AS350 and the EC130) anticipated to be used at the Heliport x 

### the configuration of the Heliport and helicopter landing and takeoff locations at McCarran x 

### potential local flight patterns in the immediate vicinity of the Heliport and McCarran x 

### the locations of existing and potential helicopter flight corridors x 

### potential flight altitudes x 

### helicopter performance data provided by local helicopter operators Details regarding the noise analysis techniques, methodology, and assumptions used in the helicopter noise analysis are provided in Appendix D. A description of existing helicopter noise exposure in the vicinity of McCarran is provided in Section 3.5.1 and a description of the existing noise exposure at the Heliport site is provided in Section 3.5.2.1. Calculated noise exposure in the vicinity of the Heliport site and of McCarran is presented in the form of contour maps. For the helicopter noise analysis, two ranges of noise exposure were considered: DNL 5 

### 60 to 65 6 

### and DNL 65. FAA Orders 1050.1E and 5050.4B state that the threshold of significance for noise impacts for most areas is when an action, compared to the no action alternative, would cause noise-sensitive areas exposed to DNL 65 and higher under the proposed action to experience an increase in DNL of 1.5 or more [I-1, I-2]. The Orders also state that when such impacts would occur, increases in DNL of 3.0 or more in noise-sensitive areas exposed to noise exposure between DNL 60 and 65 under the Proposed Action, should also be disclosed, although such increases are not considered to constitute a significant impact. FAA Orders 1050.1E and 5050.4B further state that FAA must give special consideration to national parks, national wildlife refuges, and tribal traditional cultural properties. Supplemental noise analysis is provided in this Chapter to address such concerns. 

### 4.1.1 Summary of Findings No residences, households, or noise-sensitive land uses would be exposed to helicopter noise of DNL 65 or higher in 2011 or 2017 under the Proposed Action. Noise levels at various locations of interest in the Overflight Area are also predicted to be below DNL 65 under both the Proposed Action and the No Action alternative. In addition, at locations where existing ambient noise levels were evaluated, the predicted noise levels for 2011 and 2017 helicopter operations alone would be comparable to or lower than ambient noise levels from all sources as measured at the same locations in 2004. Implementation of the Proposed Action would not result in significant noise impacts compared to the No Action alternative; therefore, no mitigation measures would be required. Helicopter noise levels in established residential communities and portions of the Lake Mead National Recreation Area beneath the Tropicana and Charleston helicopter flight corridors associated 4 As described in the following sections and in Appendix D, it has been assumed that some Grand Canyon helicopter air tour activity would remain at McCarran Intern ational Airport and that so me would occur at a different location under both the Proposed Action and the No Action alternative. However, it is noted that the proposed Heliport could accommoda te all the Grand Canyon helicopter air tou r activity that may remain at McCarran and other airport loca tions in the Las Vegas region. 5 DNL = day-night average sound level. See Section 3. 5 and Appendix D for the definition and description of DNL. 6 The FAA does not require analysis of DNL 60 to 65 noise exposure when no significant noise impacts are expected within the area exposed to DNL 65 and highe r under the Proposed Ac tion when compared with the No Action alternative. However, Clark County agencies uses information regarding noise exposure between DNL 60 and DNL 65 for local planning purposes and th erefore DNL 60 noise contour s are depicted on exhibits in this EA. Final EA for a Southern Nevada Regional Heliport IV-2 December 2008 Environmental ConsequencesClark County Department of Aviation 

### with Grand Canyon helicopter tour overflights would be lower under the Proposed Action than the No Action alternative, because there would be fewer overflights. Section 4.6 summarizes the results of a supplementary noise analysis conducted for parks and cultural properties. 

### 4.1.2 Environmental Consequences The potential for significant noise impacts related to the Proposed Action was determined by considering the following: x 

### Cumulative helicopter noise exposure at and near the Heliport site and McCarran International Airport x 

### Cumulative helicopter noise exposure at noise-sensitive locations beneath or near existing helicopter flight corridors and potential helicopter flight corridors associated with the Heliport site As discussed in Sections 2.5.1 and 2.5.2, some helicopter operations are anticipated to occur at a facility other than McCarran or the proposed Heliport site under the Proposed Action and No Action alternative. The specific effects of those helicopter operations (i.e., the helicopter operations not at McCarran or the proposed Heliport Site) on people, households, and noise sensitive land uses in the Overflight Area were not evaluated in this EA. Appendix D provides additional information regarding the distribution of helicopter operations in 2011 and 2017 under the Proposed Action and No Action alternative. 4.1.2.1 Proposed Action Noise exposure contours were developed for the two locations expected to accommodate Grand Canyon helicopter air tour operations under the Proposed Action: the Heliport site and McCarran International Airport. Although Grand Canyon helicopter air tour operators have stated their support for the construction and operation of the heliport at the South of Sloan site, it has been assumed that some number of Grand Canyon helicopter air tour operations would continue at McCarran even after the Heliport is constructed and operational. Continued activity at McCarran is not part of the Proposed Action, but rather a planning assumption reflecting the fact that CCDOA has limited ability to prevent an operator from maintaining its base at McCarran. The CCDOA consulted with the helicopter operators, the FAA, and other stakeholders to identify potential flight corridors associated with the Heliport site. Existing 7 

### and potential flight corridors are shown on Exhibit IV-1 . Three potential flight corridor scenarios are evaluated in this EA for the Heliport site. Each scenario consists of one primary corridor to and from the Heliport site and a sunset return corridor to the Heliport site. Under Scenario A, the Henderson flight corridor would be

7 The helicopter air tour operators based at McCarran Inte rnational Airport and the FAA have executed Letters of Agreement establishing preferred helic opter flight corridors for Grand Canyon helicopter tour operations originating at McCarran. These Letters of Agreement are intended to ensure safety, mini mize noise levels in residential areas, and comply with FAA ATC guidelines while the helicopt er operators are in controlled airspace. The potential helicopter flight corridors analyzed in this EA could be a guide for future Letters of Agreement between the helicopter operators and the FAA, although the Letters of Agreement would not be applicable outside of controlled airspace. Final EA for a Southern Nevada Regional Heliport IV-3 December 2008 Environmental Consequences

### This page intentionally left blankClark County Department of Aviation

Final EA for a Southern Nevada Regional Heliport Environmental Consequences December 2008 

### Existing and Potential Helicopter Flight Corridors to and from the Grand Canyon Sources: Clark County Department of Aviation; Ricondo & Associates, Inc., September 2007. Prepared by: Ricondo & Associates, Inc., April 2008. 

# ^ _ Henderson Henderson

Boulder City Boulder City Eldorado Wilderness Area Black Canyon Wilderness Area Pinto Valley Wilderness Area

Boulder City Boulder City Las Vegas Las Vegas

South of Sloan (Proposed Action) McCarran International Airport Rendezvous Point 

# A
160

159 41

165 161 Lake Mead 

# §  ̈ ¦ 215 

# £ ¤

95



# £ ¤

95 

# §  ̈ ¦

15 

# §  ̈ ¦

15



# £ ¤

95 L Sunrise Mountain Natural Area

Lake Mead National Recreation Area

North McCullough Wilderness Area Sloan Canyon National

Conservation Area

South McCullough Wilderness Area McCullough Jean Henderson Tropicana Charleston Strip Railroad

1 mile 2 miles 1 mile 1 2 3 miles mile 3 2

Jean Airport Henderson Executive Airport Boulder City Municipal Airport North Las Vegas Airport 

### Legend

Exhibit IV-1 Proposed heliport site 

# ^ _

0 4 miles 

### Flight Corridor Identification Charleston Tropicana Henderson McCullough Jean Strip Railroad Existing arrival flight corridor along Charleston Boulevard Existing departure flight corridor along Tropicana Avenue South of Sloan potential flight corridor #1 South of Sloan potential flight corridor #2 South of Sloan potential flight corridor #3 South of Sloan potential flight corridor #4 (at sunset only) McCarran International Airport existing flight corridor to or from the Grand Canyon Potential flight corridor to and/or from the Grand Canyon Corridor boundary Potential flight corridor from the Grand Canyon (during and after sunset) Direction of traffic Helicopter flight corridors

Flight path allowed by Congressional legislation for helicopter tours originating or concluding at the South of Sloan site and crossing the Sloan Canyon National Conservation Area
Primary road Railroad Secondary/State road Jurisdictional boundary Other features National Conservation Area, Wilderness Area, Natural Area, or National Recreation Area Boulder City conservation easement

### This page intentionally left blankClark County Department of Aviation 

### the primary flight corridor for helicopter operations to and from the Heliport site. Under Scenario B, the McCullough flight corridor would be the primary flight corridor. In accordance with Public Law 109-115 [I-6] the McCullough flight corridor represents the only route that can be used by Grand Canyon helicopter tour operators to cross the Sloan Canyon NCA if the flight is starting from or ending at the Heliport site. Under Scenario C, the Jean flight corridor would be the primary flight corridor. All three scenarios under the Proposed Action include a secondary flight corridor, Strip Railroad, for sunset and evening arrivals only. Flights on the Strip Railroad corridor would follow the existing Charleston corridor past the western side of McCarran, along the railroad tracks and I-15. Noise along the flight corridors is discussed in more detail in Section 4.1.2.3. Noise exposure was analyzed for the anticipated first year of operations at the Heliport site (2011), and for conditions in a future year (2017). Noise exposure contours for the Proposed Action (Scenarios A, B, and C) for 2011 and 2017 superimposed onto maps of generalized existing land uses are presented on Exhibits IV-2 and IV-3 , respectively. The noise exposure contours for each flight corridor scenario differ slightly because of differences in flight paths between the takeoff/landing areas at the Heliport site and the helicopter flight corridors. For example, helicopter traffic on the Henderson flight corridor to and from the Heliport site would follow a different path when departing or arriving to the site, and therefore result in a different noise exposure pattern near the Heliport site than traffic to and from the McCullough flight corridor. Differences in noise contours are minimized by the fact that most differences in potential flight paths would occur outside the 60 and 65 DNL contours. No residences, or noise-sensitive land uses would be exposed to helicopter noise of DNL 65 and higher in either 2011 or 2017 under the Proposed Action under any of the three scenarios for potential flight corridors. As no existing noise-sensitive land uses would be exposed to DNL 65 and higher in 2011 or 2017, no significant changes in helicopter noise (i.e., an increase or decrease of 1.5 or more in noise-sensitive areas exposed to helicopter noise of DNL 65 or higher) would occur as a result of the Proposed Action. As discussed in Section 4.1.2.3, the Proposed Action would result in a reduction in the number of overflights of residences and portions of the Lake Mead National Recreation Area along the existing Grand Canyon helicopter air tour flight corridors. As a result, helicopter noise exposure would be less under the Proposed Action than under the No Action alternative along the existing Tropicana and Charleston flight corridors. 4.1.2.2 No Action Alternative Noise exposure contours for 2011 and 2017 superimposed onto a map of generalized land uses for the No Action alternative are presented on Exhibit IV-4 . One flight corridor scenario was used for the analysis associated with the No Action alternative based on the continued use of the existing Charleston and Tropicana corridors to and from McCarran. No residences, households, or noise-sensitive land uses would be exposed to helicopter noise of DNL 65 or higher in either 2011 or 2017 under the No Action alternative. However, noise related to helicopter operations along existing helicopter flight corridors would not be reduced under the No Action alternative, and residents and portions of the Lake Mead National Recreation Area along those flight corridors would continue to experience helicopter overflights and their associated noise exposure. In addition, it is anticipated that some helicopter operations might move from McCarran to other facilities in Clark County under the No Action alternative and additional routes could be established from other facilities over residential areas. Final EA for a Southern Nevada Regional Heliport IV-5 December 2008 Environmental Consequences

### This page intentionally left blankClark County Department of Aviation

Final EA for a Southern Nevada Regional Heliport Environmental Consequences December 2008 

### 2011 Helicopter Noise Exposure Contours over Generalized Existing Land Uses Proposed Action Sources: Brown-Buntin Associates, Inc., September 2007 (noise exposure contours); Ricondo & Associates, Inc., September 2007, based on existing land use data provided by the Clark County Department of Aviation, February 2005. Prepared by: Ricondo & Associates, Inc., April 2008. 

## î î

î î î î î

# #
# #

# #

# #

# # å

å å

å å

å å å å å å å å å å å UNLV7R 19L25L25R 19R7L 

### 1L 1R 

### McCarran International AirportKoval Ln.Pecos Rd.Eastern Ave.S. Las Vegas Blvd. Tropicana Ave.

Russell Rd.

Sunset Rd. Russell Rd.

Sunset Rd. Tropicana Ave.

DNL 60 DNL 65


# §  ̈ ¦

15 

# Unincorporated

Clark County Legend

Exhibit IV-2 0 3,000 feet * Recreation includes commercial and non-profit recreational facilities

Street Interstate highway U.S. route Jurisdictional boundary Airport property Vacant / open space Park / recreation* Mobile home Commercial Industrial Public DNL = Day-Night Average Sound Level - A metric used to describe the existing and predicted cumulative noise exposure for communities surrounding an airport. DNL is expressed in A-weighted decibels (dBA) and represents the average noise level over a 24-hour period. In calculating DNL, the average sound level for each hour during the nighttime period (10:00 p.m. to 6:59 a.m.) is increased by a 10-decibel weighting penalty. 2011 DNL 65 helicopter noise exposure contour

School 

## n Religious facility 

## î Hospital 

## G Structure listed in National Register of Historic Places 

## ^ Day care 

## # Noise sensitive facilities

Other features Generalized existing land uses Residential multi-family Residential single-family



# §  ̈ ¦ £ ¤ Railroad 2011 DNL 60 helicopter noise exposure contour (shown for informational purposes only) 

### South of Sloan - Henderson Corridor Scenario 

## City of Henderson Las Vegas Blvd . 

# §  ̈ ¦

15 DNL 60
DNL 65 

## Unincorporated

Clark County Potential/existing heliport site area 

### South of Sloan - McCullough Corridor Scenario 

## City of Henderson

Las V

egas B

lvd. 

# §  ̈ ¦

15 DNL 60
DNL 65 

## Unincorporated

Clark County South of Sloan - Jean Corridor Scenario 

## City of Henderson Las Vegas Blvd. 

# §  ̈ ¦

15 DNL 60
DNL 65 

## Unincorporated

Clark County

### This page intentionally left blankClark County Department of Aviation

Final EA for a Southern Nevada Regional Heliport Environmental Consequences December 2008 

### 2017 Helicopter Noise Exposure Contours over Generalized Existing Land Uses Proposed Action Sources: Brown-Buntin Associates, Inc., September 2007 (noise exposure contours); Ricondo & Associates, Inc., September 2007, based on existing land use data provided by the Clark County Department of Aviation, February 2005. Prepared by: Ricondo & Associates, Inc., April 2008. 

## î î

î î î î î

# #
# #

# #

# #

# # å

å å

å å

å å å å å å å å å å å UNLV7R 19L25L25R 19R7L 

### 1L 1R 

### McCarran International AirportKoval Ln.Pecos Rd.Eastern Ave.S. Las Vegas Blvd. Tropicana Ave.

Russell Rd.

Sunset Rd. Russell Rd.

Sunset Rd. Tropicana Ave.

DNL 60 DNL 65


# §  ̈ ¦

15 

# Unincorporated

Clark County Legend

Exhibit IV-3 0 3,000 feet * Recreation includes commercial and non-profit recreational facilities

Street Interstate highway U.S. route Jurisdictional boundary Airport property Vacant / open space Park / recreation* Mobile home Commercial Industrial Public DNL = Day-Night Average Sound Level - A metric used to describe the existing and predicted cumulative noise exposure for communities surrounding an airport. DNL is expressed in A-weighted decibels (dBA) and represents the average noise level over a 24-hour period. In calculating DNL, the average sound level for each hour during the nighttime period (10:00 p.m. to 6:59 a.m.) is increased by a 10-decibel weighting penalty. 2017 DNL 65 helicopter noise exposure contour

School 

## n Religious facility 

## î Hospital 

## G Structure listed in National Register of Historic Places 

## ^ Day care 

## # Noise sensitive facilities

Other features Generalized existing land uses Residential multi-family Residential single-family



# §  ̈ ¦ £ ¤ Railroad 2017 DNL 60 helicopter noise exposure contour (shown for informational purposes only) 

### South of Sloan - Henderson Corridor Scenario 

## City of Henderson Las Vegas Blvd . 

# §  ̈ ¦

15 DNL 60
DNL 65 

## Unincorporated

Clark County Potential/existing heliport site area 

### South of Sloan - McCullough Corridor Scenario 

## City of Henderson

Las V

egas B

lvd. 

# §  ̈ ¦

15 DNL 60
DNL 65 

## Unincorporated

Clark County South of Sloan - Jean Corridor Scenario 

## City of Henderson Las Vegas Blvd. 

# §  ̈ ¦

15 DNL 60
DNL 65 

## Unincorporated

Clark County

### This page intentionally left blankClark County Department of Aviation

Final EA for a Southern Nevada Regional Heliport Environmental Consequences December 2008 

### 2011 and 2017 Helicopter Noise Exposure Contours over Generalized Existing Land Uses No Action Alternative Sources: Brown-Buntin Associates, Inc., September 2007 (noise exposure contours); Ricondo & Associates, Inc., September 2007, based on existing land use data provided by the Clark County Department of Aviation, February 2005. Prepared by: Ricondo & Associates, Inc., April 2008. 

### Legend

Exhibit IV-4 0 3,000 feet * Recreation includes commercial and non-profit recreational facilities

Street Interstate highway U.S. route Jurisdictional boundary Airport property Vacant / open space Park / recreation* Mobile home Commercial Industrial Public DNL = Day-Night Average Sound Level - A metric used to describe the existing and predicted cumulative noise exposure for communities surrounding an airport. DNL is expressed in A-weighted decibels (dBA) and represents the average noise level over a 24-hour period. In calculating DNL, the average sound level for each hour during the nighttime period (10:00 p.m. to 6:59 a.m.) is increased by a 10-decibel weighting penalty. DNL 65 helicopter noise exposure contour

School 

## n Religious facility 

## î Hospital 

## G Structure listed in National Register of Historic Places 

## ^ Day care 

## # Noise sensitive facilities

Other features Generalized existing land uses Residential multi-family Residential single-family



# §  ̈ ¦ £ ¤ Railroad DNL 60 helicopter noise exposure contour (shown for informational purposes only) Potential/existing heliport site area



## î î

î î î î î

# #
# #

# #

# #

# # å

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å å

å å å å å å å å å å å UNLV7R 19L25L25R 19R7L 

### 1L 1R 

### McCarran International Airport - 2011Koval Ln.Pecos Rd.Eastern Ave.S. Las Vegas Blvd. Tropicana Ave.

Russell Rd.

Sunset Rd. Russell Rd.

Sunset Rd. Tropicana Ave.

DNL 60 DNL 65


# §  ̈ ¦

15 

# Unincorporated

Clark County

î î

î î î î î

# #
# #

# #

# #

# # å

å å

å å

å å å å å å å å å å å UNLV7R 19L25L25R 19R7L 

### 1L 1R 

### McCarran International Airport - 2017Koval Ln.Pecos Rd.Eastern Ave.S. Las Vegas Blvd. Tropicana Ave.

Russell Rd.

Sunset Rd. Russell Rd.

Sunset Rd. Tropicana Ave.

DNL 60 DNL 65


# §  ̈ ¦

15 

# Unincorporated

Clark County

### This page intentionally left blankClark County Department of Aviation 

### 4.1.2.3 Overflight Area Noise exposure within the Overflight Area associated with the potential helicopter flight corridors for the proposed Heliport is dependent on a number of factors including the altitude at which the helicopters are flown. For the purposes of the noise analysis, the lowest altitude analyzed for helicopter flight corridors was 300 feet AGL. This is the minimum altitude above the ground required by 14 CFR Part 135, Operating Requirements: Commuter and On Demand Operations and Rules Governing Persons on Board Such Aircraft [IV-1], for helicopters carrying a passenger for fare. However, according to the air tour operators, the minimum expected vertical distance between the helicopters and the terrain along the routes during Grand Canyon helicopter air tours would be 500 feet, or higher in some areas, when feasible. This would be a voluntary action on the part of the air tour operators, unless otherwise required by the Act. 8 

### Helicopter noise exposure near existing and potential helicopter flight corridors was evaluated for the ten locations described in Section 3.5.2, including FAA locations L05 and L07 within the Lake Mead National Recreation Area 9 

### , plus seven supplemental sites. The seven supplemental sites (grid points) were identified to represent typical noise-sensitive locations in the Las Vegas region, such as residential areas, schools, recreation areas, and wildlife habitat. These locations are shown on Exhibit IV-5 . Table IV-1 indicates the land use or receptor represented by the grid points, and summarizes the ranges of predicted helicopter noise exposure for each grid point under the Proposed Action and the No Action alternative. Helicopter noise levels are reported in terms of cumulative (DNL) and single-event (L max 

### ) exposure. The L max 

### is considered a supplementary noise metric, and Lmax values are reported for informational purposes. Based on the INM grid point analysis, the highest helicopter DNLs would occur at grid points R1 (recreation area/trail) and G7 (residential area). The lowest helicopter DNLs (less than 25 dBA) would occur at grid points R4 (undeveloped land) and G4 (recreation area/trail). At all grid points, calculated helicopter DNLs are predicted to be below 65 and differences in calculated DNLs between the Proposed Action and the No Action alternative would be less than significant. In addition, at Sites R1 through R8, and FAA Sites L05 and L07, predicted DNLs from helicopter operations alone under the Proposed Action for 2011 and 2017 are anticipated to be comparable to or less than existing DNL values as measured during ambient noise level monitoring at the same locations in 2004 . 

### The highest maximum (L max 

### ) helicopter noise levels would also occur at grid points R1 and R7 and the lowest helicopter L max 

### noise levels would also occur at grid points R4 and G4.

8 14 CFR Part 135, Operating Requirements: Commuter and On Demand Operations and Rules Governing Persons on Board Such Aircraft , requires a minimum altitude of 300 feet AGL for helicopter operations when over congested areas; however, the Grand Canyon he licopter tour operators currently attempt to achieve a minimum altitude of 500 feet AGL. 9 Federal Aviation Administration, Baseline Ambient Sound Levels in Lake Mead National Recreation Area (DOT-VNTSC-FAA-06-13), April 2006. Final EA for a Southern Nevada Regional Heliport IV-9 December 2008 Environmental Consequences

### This page intentionally left blankClark County Department of Aviation

Final EA for a Southern Nevada Regional Heliport Environmental Consequences December 2008 

### Noise Sensitive Areas in the Vicinity of the Overflight Area Sources: Clark County Department of Aviation; Ricondo & Associates, Inc., September 2007; Brown-Buntin Associates, Inc. (ambient noise monitorin g and supplemental grid points); Federal Aviation Administration, "Baseline Ambient Sound Levels in Lake Mead National Recreation Area," April 200 6 (FAA noise monitoring sites). Prepared by: Ricondo & Associates, Inc., August 2008. 

# ^ _ ! 

# A
! 

# A
! 

# A

! 

# A ! 

# A ! 

# A ! 

# A ! 

# A

! 

# A

! 

# A ! 

# A ! 

# A

! 

# A
! 

# A ! 

# A

! 

# A ! 

# A Henderson Henderson

Boulder City Boulder City Las Vegas Las Vegas

Eldorado Wilderness Area Black Canyon Wilderness Area Lake Mead National Recreation Area Pinto Valley Wilderness Area

L07

Boulder City Boulder City

South of Sloan (Proposed Action) McCarran International Airport Rendezvous Point 

# A
160

159 41

165 161 Lake Mead 

# §  ̈ ¦ 215 

# £ ¤

95



# £ ¤

95 

# §  ̈ ¦

15 

# §  ̈ ¦

15



# £ ¤

95 L Sunrise Mountain Natural Area

North McCullough Wilderness Area Sloan Canyon National

Conservation Area

South McCullough Wilderness Area McCullough Jean Henderson Tropicana Charleston Strip Railroad G7

G6 G5 G4 G3 G2

G1

R8 R7

R6 R5 R4 R3 R2 R1

L05

Jean Airport Henderson Executive Airport Boulder City Municipal Airport North Las Vegas Airport 

### Legend

Exhibit IV-5 Proposed heliport site 

# ^ _

Primary road

0 4 miles Railroad Secondary/State road Jurisdictional boundary Other features McCarran International Airport existing flight corridor to or from the Grand Canyon Potential flight corridor to and/or from the Grand Canyon Corridor boundary Potential flight corridor from the Grand Canyon (during and after sunset) Direction of traffic Helicopter flight corridors Ambient noise monitoring grid point 

### ! 

# A

Flight path allowed by Congressional legislation for helicopter tours originating or concluding at the South of Sloan site and crossing the Sloan Canyon National Conservation Area

National Conservation Area, Wilderness Area, Natural Area, or National Recreation Area Boulder City conservation easement Supplemental grid point 

### ! 

# A FAA noise monitoring site 

### ! 

# A

Flight Corridor Identification Charleston Tropicana Henderson McCullough Jean Strip Railroad Existing arrival flight corridor along Charleston Boulevard Existing departure flight corridor along Tropicana Avenue South of Sloan potential flight corridor #1 South of Sloan potential flight corridor #2 South of Sloan potential flight corridor #3 South of Sloan potential flight corridor #4 (at sunset only)

### This page intentionally left blankClark County Department of Aviation Table IV-1 Summary of Helicopter Noise Levels at Locations of Interest Nearest Helicopter Distance to Nearest Measured Ambient Predicted Helicopter Noise Levels Predicted Helicopter Noise Predicted Single Event Helicopter Grid Point 1/ Representative Land Use Flight Corridor(s) 2/ Flight Corridor(s) (feet) Noise Level (DNL) 3/ (DNL) No Action Alternative 7/ Levels (DNL) Proposed Action 7/ Noise Levels (L max ) 4/ 2011 2017 2011 2017 EC130 SA350D R1 Recreation area (trail) Charleston 0 50.6 44-53 45-55 39-49 40-50 61-78 65-80 R2 Abandoned mine Tropicana 3,310 59.7 34-37 34-38 29-32 30-33 47-53 51-59 R3 Undeveloped land Henderson (Inbound/Outbound) 7,600/2,340 55.1 n.a. n.a. 39-43 40-43 53-58 55-62 R4 Undeveloped land Henderson (Inbound/Outbound) 21,580/16,330 56.2 n.a. n.a. <25 <25 <35 <35 R5 Sloan Canyon petroglyphs McCullough (Inbound/Outbound) 8,110/13,520 50.2 n.a. n.a. 26-28 26-29 31-37 36-43 R6 Wilderness area with hiking trails McCullough (Inbound/Outbound) 2,580/2,580 49.4 n.a. n.a. 40-43 40-44 51-56 54-60 R7 Wilderness area with hiking trails Jean (Inbound/Outbound) 3,170/2,090 46.8 n.a. n.a. 42-44 42-44 55-59 57-63 R8 Electric power substation Jean (Inbound/Outbound) 1,810/3,410 45.1 n.a. n.a. 42-43 43-45 46-52 51-57 G1 Residential/school area Charleston 5,300 n.a. 27-33 28-34 22-28 22-28 39-45 44-51 G2 Recreation area (campsite) Tropicana 1,430 n.a. 43-47 44-48 38-43 39-43 59-66 62-69 G3 Residential area Henderson (Inbound/Outbound) 8,080/2,880 n.a. n.a. n.a. 36-40 36-40 49-55 52-59 G4 Recreation area (trail) Henderson (Inbound/Outbound) 22,420/17,110 n.a. n.a. n.a. <25 <25 <35 <35 G5 Wilderness/habitat area McCullough (Inbound/Outbound) 3,320/8,730 n.a. n.a. n.a. 33-37 33-37 47-53 51-57 G6 Wilderness/habitat area Jean (Inbound/Outbound) 8,200/13,580 n.a. n.a. n.a. 26-28 26-29 31-37 36-43 G7 Residential area Strip Railroad 0 n.a. n.a. n.a. 37-47 38-48 61-78 65-80 L05 5/ Semi-primitive/natural McCullough/Jean (Outbound) 2,440 41.8 6/ n.a. n.a. 36-41 36-42 53-58 55-62 L07 5/ High use Charleston 1,100 55.1 6/ 43-48 44-49 38-44 39-45 60-70 63-73 Notes: n.a. = Not applicable DNL = Day-night average sound level, expressed in A-weighted decibels 1/ Grid point locations are shown on Exhibit IV-5. Noise meas urements were conducted at Sites R1 through R8 and Sites L05 and L07 in 2004. 2/ Existing and potential helicopter fli ght corridors are shown on Exhibit IV-5. 3/ Ambient noise level data are from Table III-2. Sites G1-G7 are supplemental grid point locations where noise levels were ca lculated using the INM. Ambient noise measurements were not conducted at those locations. 4/ Predicted L max values are shown as a range for individual overflights by th e SA350D and EC130 helicopter types at altitudes ranging from 300 feet to 1500 feet above the observer location (grid point). 5/ FAA ambient noise monitoring site and data as described in Baseline Ambient Sound Levels in Lake Mead National Recreation Area (DOT-VNTSC-FAA-06-13), April 2006. 6/ DNL values estimated from hourly L eq data measured by the FAA as referenced above. 7/ Predicted DNL values are for potential helicopter flight altitudes ran ging from 300 feet to 1500 feet above the observer loc ation (grid point). Source: Brown-Buntin Associates, Inc. Prepared by: Ricondo & Associates, Inc., December 2008

Final EA for a Southern Nevada Regional Heliport IV-11 December 2008 Environmental Consequences

### This page intentionally left blankClark County Department of Aviation 

## 4.2 Compatible Land Use According to Appendix A of 14 CFR Part 150 [III-4] and FAA Advisory Circular 150/5020-1, Noise Control and Compatibility Planning for Airports [IV-2], a proposed action is considered to have a significant impact on land use compatibility if it causes significant increases in noise exposure over residential or other noise-sensitive land uses, such as schools, parks, and historic buildings, within areas exposed to aircraft noise of DNL 65 and higher. In addition to the consideration of aircraft noise impacts, other types of land use impacts to be considered in environmental assessments include disruption of communities, relocation of businesses, and induced socioeconomic impacts. Potential disruptions to communities, effects on businesses, and induced socioeconomic impacts associated with the implementation of the Proposed Action are discussed in Section 4.3. Potential impacts to floodplains and floodways are discussed in Section 4.13. Potential impacts to fish, wildlife, and plants are discussed in Section 4.10; federally listed threatened and endangered species, including potential impacts to critical habitat are discussed in Section 4.11. As discussed in FAA Order 1050.1E, the compatible land use section of EAs for airport actions must include documentation to support the required airport sponsor’s assurance under 49 USC 47107(a)(10) that appropriate action, including the adoption of zoning laws, has been or will be taken, to the extent reasonable, to promote airport/community land use compatibility. 10 

### The Clark County Board of County Commissioners has included a land use compatibility assurance letter in this EA, as provided in Appendix E . 

### 4.2.1 Summary of Findings Under both the Proposed Action and the No Action alternative, residents beneath and near existing helicopter flight corridors would continue to experience helicopter overflights and noise. The number of Grand Canyon helicopter tour overflights of established residential communities along the Tropicana and Charleston helicopter flight corridors would be lower under the Proposed Action when compared to the No Action alternative and helicopter noise levels would also be lower in those communities. Implementation of the Proposed Action would affect helicopter flight patterns in the Overflight Area; however, helicopter noise exposure is anticipated to be less than the FAA’s land use compatibility threshold of DNL 65 and is not expected to adversely affect community land use compatibility within the Area of Disturbance or the Overflight Area. 

### 4.2.2 Environmental Consequences 4.2.2.1 Proposed Action The Heliport site is located on BLM managed public land in unincorporated Clark County within the South County Planning Area. The Clark County Department of Comprehensive Planning adopted a land use plan for the South County Planning Area in 1994 [III-5] and updated the land use plan map in 2005. The Heliport site is within the County land use designation Open Land. 11 

### While the Open Land designation allows for some limited uses (e.g., grazing), it is anticipated that future development outside the BLM disposal area (generally around the Heliport site) would be limited as land is not available for disposal. 10 The land use compatibility category is an evaluation of effects on the manmade environment based on a review of 14 CFR Part 150 land use categori es; see other sections of this EA for discussions of noise relative to wildlife and DOT Section 4(f) lands. 11 The land use category is called open space on Exhibits IV-6 and IV-7. See Appendix E for detailed description of land use designations under th e South County Planning Area. Final EA for a Southern Nevada Regional Heliport IV-12 Environmental ConsequencesClark County Department of Aviation 

### In 2007 the City of Henderson annexed about 3,455 acres of land located within the BLM disposal area north/northeast of the Heliport site. The City of Henderson has not prepared a land use plan for the annexed land, which is located in the West Henderson Planning Area. The land use plan for the South County Planning Area, prepared by the Clark County Department of Comprehensive Planning, would continue to apply until the City of Henderson updates the land use designation applicable to this area. Two ranges of noise exposure were considered: DNL 60 to 65 and DNL 65 and higher. The noise contours were superimposed onto maps of generalized planned land uses to determine if projected noise levels would be incompatible with land use designations included in adopted land use plans encompassing the Area of Disturbance and McCarran. Helicopter noise exposure contours for the Proposed Action in 2011 and 2017 are presented over generalized planned land uses on Exhibits IV-6 and IV-7 , respectively. As shown on the exhibits, helicopter noise of DNL 65 and higher would not extend beyond the property boundaries of the Heliport site or McCarran International Airport in 2011 or 2017. No planned noise-sensitive land uses would be exposed to helicopter noise of DNL 65 and higher in either 2011 or 2017 as a result of the Proposed Action. 4.2.2.2 No Action Alternative Noise exposure contours for the No Action alternative in 2011 and 2017 are presented over generalized planned land uses on Exhibit IV-8 . As shown, the areas that would be exposed to DNL 65 and higher from helicopter operations would be contained within the McCarran boundaries. No existing or planned noise-sensitive land uses in the vicinity of McCarran would be exposed to helicopter noise of DNL 65 and higher in either 2011 or 2017. 4.2.2.3 Overflight Area Between the Heliport site and the Rendezvous Point 12 

### , planned land uses beneath the Henderson flight corridor generally represent a continuation of existing land use patterns, with single- and multi-family residential, commercial, industrial, recreation, public, and open space uses. The planned land uses also include new areas of industrial, mixed use, and low-density residential uses occupying a portion of what is currently vacant land. (See Exhibit III-12.) Most areas depicted as vacant lands on the existing land use exhibits are planned as open space. However, these lands are outside the BLM disposal area and are unavailable for community development. Flights on the McCullough flight corridor would pass primarily over land designated as open space or vacant land. Flights on the Jean flight corridor would pass over open space, vacant land, and a small area of planned industrial land use, which is currently vacant, and a small area of public land use. Almost all Open Land is federal land, except for areas within Boulder City, where the flight corridors pass over the Boulder City conservation easement 13 

### and a recreation area. Flights on the Strip Railroad corridor would pass over single- and multi-family residential, commercial,

12 As described in Section 3.2.1, the existing and potential helicopter flight corridors are the same between the Rendezvous Point and the Grand Canyon and no changes would occur as a result of the Proposed Action beyond the Rendezvous Point. See Exhibit III-8. 13 Clark County purchased a conservation easement on ab out 85,000 acres of desert tortoise habitat in the Eldorado Valley. Final EA for a Southern Nevada Regional Heliport IV-13 December 2008 Environmental ConsequencesClark County Department of Aviation

Final EA for a Southern Nevada Regional Heliport Environmental Consequences December 2008 

### 2011 Helicopter Noise Exposure Contours over Generalized Planned Land Uses Proposed Action Sources: Brown-Buntin Associates, Inc., September 2007 (noise exposure contours); Ricondo & Associates, Inc., September 2007, based on data obtai ned from the Clark County Department of Comprehensive Planning, February 2005. Prepared by: Ricondo & Associates, Inc., April 2008. 

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### McCarran International AirportKoval Ln.Pecos Rd.Eastern Ave.S. Las Vegas Blvd. Tropicana Ave.

Russell Rd.

Sunset Rd. Russell Rd.

Sunset Rd. Tropicana Ave.

DNL 60 DNL 65


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# Unincorporated

Clark County Legend

Exhibit IV-6 0 3,000 feet DNL = Day-Night Average Sound Level - A metric used to describe the existing and predicted cumulative noise exposure for communities surrounding an airport. DNL is expressed in A-weighted decibels (dBA) and represents the average noise level over a 24-hour period. In calculating DNL, the average sound level for each hour during the nighttime period (10:00 p.m. to 6:59 a.m.) is increased by a 10-decibel weighting penalty. 2011 DNL 65 helicopter noise exposure contour 2011 DNL 60 helicopter noise exposure contour (shown for informational purposes only) 

### South of Sloan - Henderson Corridor Scenario 

## City of Henderson Las Vegas Blvd . 

# §  ̈ ¦

15 DNL 60
DNL 65 

## Unincorporated

Clark County Potential/existing heliport site area 

### South of Sloan - McCullough Corridor Scenario 

## City of Henderson

Las V

egas B

lvd. 

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15 DNL 60
DNL 65 

## Unincorporated

Clark County South of Sloan - Jean Corridor Scenario 

## City of Henderson Las Vegas Blvd. 

# §  ̈ ¦

15 DNL 60
DNL 65 

## Unincorporated

Clark County

* Recreation includes commercial and non-profit recreational facilities

Street Interstate highway U.S. route Jurisdictional boundary Airport property Vacant / tax exempt Park / recreation* Commercial Mixed use Industrial Open space Public

School 

## n Religious facility 

## î Hospital 

## G Structure listed in National Register of Historic Places 

## ^ Day care 

## # Noise sensitive facilities

Other features Generalized planned land uses Residential multi-family Residential single-family



# §  ̈ ¦ £ ¤ Railroad Major development project

### This page intentionally left blankClark County Department of Aviation

Final EA for a Southern Nevada Regional Heliport Environmental Consequences December 2008 

### 2017 Helicopter Noise Exposure Contours over Generalized Planned Land Uses Proposed Action Sources: Brown-Buntin Associates, Inc., September 2007 (noise exposure contours); Ricondo & Associates, Inc., September 2007, based on data obtai ned from the Clark County Department of Comprehensive Planning, February 2005. Prepared by: Ricondo & Associates, Inc., April 2008. 

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### 1L 1R 

### McCarran International AirportKoval Ln.Pecos Rd.Eastern Ave.S. Las Vegas Blvd. Tropicana Ave.

Russell Rd.

Sunset Rd. Russell Rd.

Sunset Rd. Tropicana Ave.

DNL 60 DNL 65


# §  ̈ ¦

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# Unincorporated

Clark County Legend

Exhibit IV-7 0 3,000 feet DNL = Day-Night Average Sound Level - A metric used to describe the existing and predicted cumulative noise exposure for communities surrounding an airport. DNL is expressed in A-weighted decibels (dBA) and represents the average noise level over a 24-hour period. In calculating DNL, the average sound level for each hour during the nighttime period (10:00 p.m. to 6:59 a.m.) is increased by a 10-decibel weighting penalty. 2017 DNL 65 helicopter noise exposure contour 2017 DNL 60 helicopter noise exposure contour (shown for informational purposes only) 

### South of Sloan - Henderson Corridor Scenario 

## City of Henderson Las Vegas Blvd . 

# §  ̈ ¦

15 DNL 60
DNL 65 

## Unincorporated

Clark County Potential/existing heliport site area 

### South of Sloan - McCullough Corridor Scenario 

## City of Henderson

Las V

egas B

lvd. 

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15 DNL 60
DNL 65 

## Unincorporated

Clark County South of Sloan - Jean Corridor Scenario 

## City of Henderson Las Vegas Blvd. 

# §  ̈ ¦

15 DNL 60
DNL 65 

## Unincorporated

Clark County

* Recreation includes commercial and non-profit recreational facilities

Street Interstate highway U.S. route Jurisdictional boundary Airport property Vacant / tax exempt Park / recreation* Commercial Mixed use Industrial Open space Public

School 

## n Religious facility 

## î Hospital 

## G Structure listed in National Register of Historic Places 

## ^ Day care 

## # Noise sensitive facilities

Other features Generalized planned land uses Residential multi-family Residential single-family



# §  ̈ ¦ £ ¤ Railroad Major development project

### This page intentionally left blankClark County Department of Aviation

Final EA for a Southern Nevada Regional Heliport Environmental Consequences December 2008 

### 2011 and 2017 Helicopter Noise Exposure Contours over Generalized Planned Land Uses No Action Alternative Sources: Brown-Buntin Associates, Inc., September 2007 (noise exposure contours); Ricondo & Associates, Inc., September 2007, based on data obtai ned from the Clark County Department of Comprehensive Planning, February 2005. Prepared by: Ricondo & Associates, Inc., April 2008. 

### Legend

Exhibit IV-8 0 3,000 feet DNL = Day-Night Average Sound Level - A metric used to describe the existing and predicted cumulative noise exposure for communities surrounding an airport. DNL is expressed in A-weighted decibels (dBA) and represents the average noise level over a 24-hour period. In calculating DNL, the average sound level for each hour during the nighttime period (10:00 p.m. to 6:59 a.m.) is increased by a 10-decibel weighting penalty. DNL 65 helicopter noise exposure contour DNL 60 helicopter noise exposure contour (shown for informational purposes only) Potential/existing heliport site area



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### McCarran International Airport - 2011Koval Ln.Pecos Rd.Eastern Ave.S. Las Vegas Blvd. Tropicana Ave.

Russell Rd.

Sunset Rd. Russell Rd.

Sunset Rd. Tropicana Ave.

DNL 60 DNL 65


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# Unincorporated

Clark County

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### McCarran International Airport - 2017Koval Ln.Pecos Rd.Eastern Ave.S. Las Vegas Blvd. Tropicana Ave.

Russell Rd.

Sunset Rd. Russell Rd.

Sunset Rd. Tropicana Ave.

DNL 60 DNL 65


# §  ̈ ¦

15 

# Unincorporated

Clark County * Recreation includes commercial and non-profit recreational facilities

Street Interstate highway U.S. route Jurisdictional boundary Airport property Vacant / tax exempt Park / recreation* Commercial Mixed use Industrial Open space Public

School 

## n Religious facility 

## î Hospital 

## G Structure listed in National Register of Historic Places 

## ^ Day care 

## # Noise sensitive facilities

Other features Generalized planned land uses Residential multi-family Residential single-family



# §  ̈ ¦ £ ¤ Railroad Major development project

### This page intentionally left blankClark County Department of Aviation 

### mixed use, industrial, park/recreational and public land uses, open space, and vacant land. In addition, flights on the Strip Railroad corridor would continue west of McCarran, follow the railroad tracks and I-15, and pass over single- and multi-family residential, commercial, and industrial land uses, open space, park/recreational areas, vacant land, and an area of public land use. Implementation of the Proposed Action would affect helicopter flight patterns in the Overflight Area and potentially result in helicopters overflying areas that are currently developed with noise-sensitive land uses or that may be developed with noise-sensitive land uses in the future. Nevertheless, as discussed in Section 4.1, helicopter noise exposure beneath and near the Overflight Area is anticipated to be less than the FAA’s land use compatibility threshold of DNL 65. As a result, helicopter noise on the ground beneath the Overflight Area is not expected to adversely affect community land use compatibility. Between McCarran and the Rendezvous Point, planned land uses beneath the Tropicana flight corridor generally represent a continuation of existing land use patterns and include single- and multi-family residential, commercial, industrial, mixed use, public, and open space land uses. Planned land uses beneath the Charleston flight corridor generally represent a continuation of existing land use patterns and include single- and multi-family residential, commercial, mixed use, industrial, park/recreational, public land uses, open space, and vacant land. Under both the Proposed Action and the No Action alternative, the Tropicana and Charleston flight corridors would continue to be utilized; however, the number of overflights of established residential communities along both corridors would be lower under the Proposed Action. 

## 4.3 Socioeconomic Impacts, Environmental Justice, and Children’s Environmental Health and Safety Risks In accordance with FAA Orders 1050.1E and 5050.4B, the three primary social impact categories to be considered in an EA are: (1) socioeconomic impacts, (2) environmental justice, and (3) children’s environmental health and safety risks. Factors to be considered when determining whether a proposed project would result in significant socioeconomic impacts include: (1) if extensive relocation of residents would be required, but insufficient replacement housing is available, and this results in a high degree of controversy; (2) if Section 206(a) of the Uniform Relocation Assistance and Real Property Acquisition Policies Act , as amended, [IV-3] is used as provision for housing of last resort; (3) if relocation of businesses, including farms, creates severe economic hardship on the community; (4) if significant disruption of employment and communities occurs; and (5) if a noticeable increase in traffic congestion or access time to community facilities cannot be prevented or minimized. Executive Order 12898, Federal Actions to Address Environmental Justice in Minority Populations and Low-Income Populations [IV-4] provides guidance to federal agencies for identifying and addressing disproportionately high environmental effects of federal programs and activities on minority and low-income populations. Projects are considered to have a significant environmental justice impact when disproportionately high segments of low-income and minority populations are affected, or when the impacts are appreciably more severe or of greater magnitude than adverse effects experienced by non-minority and/or non-low-income populations. Executive Order 13045, Protection of Children from Environmental Health Risks and Safety Risks [IV-5], directs federal agencies to ensure that potential environmental health risks and safety risks Final EA for a Southern Nevada Regional Heliport IV-17 December 2008 Environmental Consequences