Loading...
4-11_Noise.pdf4.11 NOISE 4.11-1 This section describes existing noise conditions in the project area, describes criteria for determining the significance of noise impacts, and estimates the likely noise that would result from implementation of the project. Where appropriate, mitigation measures are recommended to reduce project-related noise impacts to less-than-significant levels. A summary of the characteristics of noise, vibration, and acoustical terms and definitions is provided in Ap- pendix G, Noise Data, of this Draft EIR. A. Fundamentals of Sound and Environmental Noise Sound is technically described in terms of amplitude (loudness) and frequency (pitch). The standard unit of sound amplitude measurement is the decibel (dB). The decibel scale is a logarithmic scale that describes the physical inten- sity of the pressure vibrations that make up any sound. The pitch of the sound is related to the frequency of the pressure vibration. Since the human ear is not equally sensitive to a given sound level at all frequencies, a special frequency-dependent rating scale has been devised to relate noise to human sensitivity. The A-weighted decibel scale (dBA) provides this compensation by discriminating against frequencies in a manner approximating the sensitivi- ty of the human ear. Noise, on the other hand, is typically defined as unwanted sound. A typical noise environment consists of a base of steady ambient noise that is the sum of many distant and indistinguishable noise sources. Superimposed on this background noise is the sound from individual local sources. These can vary from an occasional aircraft or train passing by to virtually continuous noise from, for example, traffic on a major highway. Several rating scales have been developed to analyze the adverse effect of community noise on people. Because environmental noise fluctuates over time, these scales consider that the effect of noise upon people is largely de- pendent upon the total acoustical energy content of the noise, as well as the time of day when the noise occurs. The Leq is a measure of ambient noise, TOWN OF TRUCKEE CANYON SPRINGS DRAFT EIR NOISE 4.11-2 while the Ldn and CNEL are measures of community noise. Each is applica- ble to this analysis and defined as follows: ¤ Leq, the equivalent energy noise level, is the average acoustic energy con- tent of noise for a stated period of time. Thus, the Leq of a time-varying noise and that of a steady noise are the same if they deliver the same acoustic energy to the ear during exposure. For evaluating community impacts, this rating scale does not vary, regardless of whether the noise occurs during the day or the night. ¤ Ldn, the Day-Night Average Level, is a 24-hour average Leq with a 10 dBA “weighting” added to noise during the hours of 10:00 p.m. to 7:00 a.m. to account for noise sensitivity in the nighttime. The logarithmic effect of these additions is that a 60 dBA 24 hour Leq would result in a measure- ment of 66.4 dBA Ldn. ¤ CNEL, the Community Noise Equivalent Level, is a 24-hour average Leq with a 5 dBA “weighting” during the hours of 7:00 p.m. to 10:00 p.m. and a 10 dBA “weighting” added to noise during the hours of 10:00 p.m. to 7:00 a.m. to account for noise sensitivity in the evening and nighttime, respectively. The logarithmic effect of these additions is that a 60 dBA 24 hour Leq would result in a measurement of 66.7 dBA CNEL. ¤ Lmin is the minimum instantaneous noise level experienced during a given period of time. ¤ Lmax is the maximum instantaneous noise level experienced during a given period of time. B. Regulatory Framework The following section summarizes the regulatory framework related to noise, including federal, State, and Town of Truckee plans, policies, and standards. TOWN OF TRUCKEE CANYON SPRINGS DRAFT EIR NOISE 4.11-3 1. Federal Laws and Regulations i. U.S. Environmental Protection Agency In 1972 Congress enacted the Noise Control Act. This Act authorized the U.S. Environmental Protection Agency (EPA) to publish descriptive data on the effects of noise and establish levels of sound “requisite to protect the pub- lic welfare with an adequate margin of safety.” These levels are separated into health (hearing loss levels) and welfare (annoyance levels), as shown in Table 4.11-1. The U.S. EPA cautions that these identified levels are not standards because they do not take into account the cost or feasibility of the levels. For protection against hearing loss, 96 percent of the population would be protected if sound levels are less than or equal to an Leq(24) of 70 Db. The “(24)” signifies an Leq duration of 24 hours. The U.S. EPA activity and inter- ference guidelines are designed to ensure reliable speech communication at about 5 feet in the outdoor environment. For outdoor and indoor environ- ments, interference with activity and annoyance should not occur if levels are below 55 dBA and 45 dBA, respectively. The noise effects associated with an outdoor Ldn of 55 dB are summarized in Table 4.11-2. At 55 dB Ldn, 95 percent sentence clarity (intelligibility) may be expected at 3.5 meters, and no community reaction. However, one percent of the population may complain about noise at this level and 17 percent may indicate annoyance. 2. State Laws and Regulations The State of California has established regulations that help prevent adverse impacts to occupants of buildings located near noise sources. Referred to as the “State Noise Insulation Standard,” it requires buildings to meet perfor- mance standards through design and/or building materials that would offset any noise source in the vicinity of the receptor. State regulations include requirements for the construction of new hotels, motels, apartment houses, and dwellings other than detached single-family TOWN OF TRUCKEE CANYON SPRINGS DRAFT EIR NOISE 4.11-4 TABLE 4.11-1 SUMMARY OF EPA NOISE LEVELS Effect Level Area Hearing loss Leq(24) < 70 dB All areas. Outdoor activity interference and annoyance Ldn < 55 dB Outdoors in residential areas and farms and other outdoor areas where people spend widely varying amounts of time and other places in which quiet is a basis for use. Leq(24) < 55 dB Outdoor areas where people spend limited amounts of time, such as school yards, play- grounds, etc. Indoor activity interference and annoyance Leq < 45 dB Indoor residential areas. Leq(24) < 45 dB Other indoor areas with human activities such as schools, etc. Source: U.S. Environmental Protection Agency, 1974. “Information on Levels of Environmen- tal Noise Requisite to Protect Public Health and Welfare with an Adequate Margin of Safety.” TABLE 4.11-2 SUMMARY OF HUMAN EFFECTS IN AREAS EXPOSED TO 55 DBA LDN Type of Effects Magnitude of Effect Speech – Indoors 100% sentence intelligibility (average) with a 5 dB margin of safety. Speech – Outdoors 100% sentence intelligibility (average) at 0.35 meters. 99%sentence intelligibility (average) at 1.0 meters. 95% sentence intelligibility (average) at 3.5 meters. Average Community Reaction None evident; 7 dB below level of significant complaints and threats of legal action and at least 16 dB below “vigorous action.” Complaints 1% dependent on attitude and other non-level related factors. Annoyance 17% dependent on attitude and other non-level related factors. Attitude Towards Area Noise essentially the least important of various factors. Source: U.S. Environmental Protection Agency, 1974. “Information on Levels of Environ- mental Noise Requisite to Protect Public Health and Welfare with an Adequate Margin of Safe- ty.” TOWN OF TRUCKEE CANYON SPRINGS DRAFT EIR NOISE 4.11-5 dwellings that are intended to limit the extent of noise transmitted into habit- able spaces. These requirements are found in the California Code of Regula- tions, Title 24 (known as the Building Standards Administrative Code), Part 2 (known as the California Building Code), Appendix Chapters 12 and 12A. For limiting noise transmitted between adjacent dwelling units, the noise in- sulation standards specify the extent to which walls, doors, and floor ceiling assemblies must block or absorb sound. For limiting noise from exterior noise sources, the noise insulation standards set an interior standard of 45 dBA CNEL in any habitable room with all doors and windows closed. In addition, the standards require preparation of an acoustical analysis demon- strating the manner in which dwelling units have been designed to meet this interior standard, where such units are proposed in an area with exterior noise levels greater than 60 dBA CNEL. The State has also established land use compatibility guidelines for determin- ing acceptable noise levels for specified land uses. The Town has adopted and modified the State’s land use compatibility guidelines, as shown in Table 4.11-3, and as discussed below. 3. Local Regulations and Policies a. Town of Truckee 2025 General Plan The Town of Truckee addresses noise in the Noise Element of the Town of Truckee 2025 General Plan. The Town’s policies extend the California Noise Insulation Standards for interior noise levels attributable to exterior sources to all proposed new single-family residences. The policies of the Noise (N) Element that are applicable to the proposed project are provided in Table 4.11-4. b. Town of Truckee Municipal Code Title 18, Development Code, Chapter 18.44 establishes regulations for noise level requirements of new development. Chapter 18.44 includes the follow- ing ordinances governing stationary noise sources that are applicable to the proposed project. TOWN OF TRUCKEE CANYON SPRINGS DRAFT EIR NOISE 4.11-6 TABLE 4.11-3 LAND USE COMPATIBILITY GUIDELINES Land Use Category Exterior Noise Exposure (CNEL, dB)a 55 60 65 70 75 80 Residential, Mobile Homes Residential in Mixed Use Development Hospitals, Schools, Congregate Care Office, Medical; Light Industrial Hotel; Commercial Neighborhood Parks, RV Parks Other Recreation; Community and Regional Parks NORMALLY ACCEPTABLE Specified land use is compatible, assuming standard con- struction practices are used. NORMALLY UNACCEPTABLE New land uses should be discouraged, but development may be allowed after a detailed noise analysis is performed, noise reduction and insulation features necessary to reduce exterior noise to “normally acceptable” levels and interior noise levels as appropriate are included in project design, and the land uses are shown to serve the greater public interests of the citizens of Truckee. CONDITIONALLY ACCEPTABLE New land uses may be allowed if detailed noise analysis is performed and noise reduction and insulation features necessary to reduce exterior noise levels to “normally acceptable” levels and interior noise levels as appropriate are included in the project design. UNACCEPTABLE New construction or development of these land uses should generally not be permitted because mitigation is usually not feasible. Note: the Truckee-Tahoe Airport has separate guidelines addressing airport noise. a Based on worst-case levels, both existing and 2025. Source: Town of Truckee, 2007. Town of Truckee 2025 General Plan. Figure N-3. TOWN OF TRUCKEE CANYON SPRINGS DRAFT EIR NOISE 4.11-7 TABLE 4.11-4 TOWN OF TRUCKEE GENERAL PLAN GOALS AND POLICIES RELEVANT TO NOISE Policy or Goal No. Goals and Policies Goal N-1 Minimize community exposure to excessive noise by ensuring compati- ble land uses relative to noise sources. N-P1.1 Allow new development only if consistent with the ground trans- portation noise compatibility guidelines illustrated in Figure N-3 [reference Table 4.11-] and the policies of this [the Noise] Element. Noise measurements used in establishing compatibility shall be measured in dBA CNEL and based on worst-case noise levels, either existing or future. N-P1.2 Require new development to mitigate exterior noise to “normally acceptable” levels in outdoor areas where quiet is a benefit, such as in the backyards of single-family homes. N-P1.3 Enforce the California Noise Insulation Standards for interior noise levels attributable to exterior sources for all proposed new single- and multi-family residences. Goal N-2 Address noise issues through the planning and permitting process. N-P2.1 Require mitigation of all significant noise impacts as a condition of project approval. N-P2.2 Require preparation of a noise analysis/acoustical study, which is to include recommendations for mitigation, for all proposed pro- jects which may result in potentially significant noise impacts to nearby noise sensitive land uses such as residences. N-P2.5 Require the application of the provisions in the California Build- ing Code Appendix Chapter II, Sections 1208A.8: Exterior Sound Transmission Control, to apply to all new single-family residences. Goal N-3 Reduce noise levels from sources such as domestic uses, construction and car stereos, and from mobile sources, including motor vehicle traffic and aircraft operations. N-P3.1 Enforce provisions of the Municipal Noise Ordinance, which lim- its maximum permitted noise levels that cross property lines and impact adjacent land uses. N-P3.2 Regulate noise from non-emergency construction activities through the Municipal Noise Ordinance. N-P3.13 Require the following standard construction noise control measures to be included as requirements at construction sites in order to minimize construction noise impacts. ¤ Equip all internal combustion engine driven equipment with intake and exhaust mufflers that are in good condition and ap- TOWN OF TRUCKEE CANYON SPRINGS DRAFT EIR NOISE TABLE 4.11-4 TOWN OF TRUCKEE GENERAL PLAN GOALS AND POLICIES RELEVANT TO NOISE (CONTINUED) 4.11-8 Policy or Goal No. Goals and Policies propriate for the equipment. ¤ Locate stationary noise generating equipment as far as possible from sensitive receptors when sensitive receptors adjoin or are near a construction project area. ¤ Utilize “quiet” air compressors and other stationary noise gen- erating equipment where appropriate technology exists. ¤ The project sponsor shall designate a “disturbance coordinator” who would be responsible for responding to any local com- plaints about construction noise. The disturbance coordinator will determine the cause of the noise complaint (e.g., starting too early, bad muffler, etc.) and will require that reasonable measures warranted to correct the problem be implemented. The project sponsor shall also post a telephone number for ex- cessive noise complaints in conspicuous locations in the vicinity of the project site. Additionally, the project sponsor shall send a notice to neighbors in the project vicinity with information on the construction schedule and the telephone number for noise complaints. Source: Town of Truckee 2025 General Plan. ¤ 18.44.040 – Exterior Noise Standards: It shall be unlawful for any per- son, at any location within the Town, to create any noise or to allow the creation of any noise on property leased, occupied, owned, or otherwise controlled by the person which does not comply with the provisions of this Section, unless the provisions of either Sections 18.44.050 (Residen- tial Interior Noise Standards) or 18.44.070 (Exceptions), below have been met. A. Exterior Levels: Exterior noise levels, when measured at any receiv- ing church, commercial, hospital, public library, residential or school property, do not conform to the provisions of this Section when they exceed the noise level standards established by Table 3-8, which has been reproduced in this Draft EIR as Table 4.11-5 below. TOWN OF TRUCKEE CANYON SPRINGS DRAFT EIR NOISE 4.11-9 TABLE 4.11-5 NOISE STANDARD BY RECEIVING LAND USE Cumulative Number of Minutes in Any Hour Noise Level Standards, dBA Day – 7:00 a.m. to 10:00 p.m. Night – 10:00 p.m. to 7:00 a.m. Hospital, Library, Religious Institutions, Residential, or School Uses 30a 55 50 15 60 55 5 65 60 1 70 65 0 75 70 Commercial Uses 30 65 60 15 70 65 5 75 70 1 80 75 0 85 80 a For example, this means the measured noise level may not exceed 55 dBA for more than 30 minutes out of any one hour time period. Source: Town of Truckee, 2011. Municipal Code, Title 18, Development Code, Chapter 18.44, Table 3-8. B. Ambient Noise Level Adjustment: In the event the measured ambi- ent noise level exceeds the applicable noise level standard in any cate- gory above, the applicable standards shall be adjusted to equal the ambient noise level. For example, if the applicable noise level stand- ard is 60 dB(A) and the ambient noise level is 63 dB(A), the applica- ble noise level standard would be adjusted to 63 dB(A). In these cas- es, a use would not exceed the applicable noise level standard if it did not increase the ambient noise level by more than 3.0 dB(A) when T OWN OF TRUCKEE CANYON SPRINGS DRAFT EIR NOISE 4.11-10 the ambient noise level is between 60 and 65 dB(A) or by more than 1.5 dB(A) when the ambient noise level is greater than 65 dB(A). H. Sensitive Land Uses: Whenever a use is proposed on a parcel where the expected noise levels generated by the use, when measured at any receiving church, hospital, public library, residential, or school prop- erty, may exceed the noise level standards established by Table 3-8 (reference Table 4.11-5), the land use permit application shall include an acoustical analysis of the effect of the noise generated by the use on the sensitive land use property. An acoustical analysis shall also be required when a commercial or industrial loading dock or area is located within 300 feet of a sensitive use. The acoustical analysis shall identify appropriate mitigation measures that reduce exterior noise levels to acceptable levels established by Table 3-8 (reference Table 4.11-5). These mitigation measures shall be incorporated into the design, construction, and operation of the use. I. Mitigation: Reasonable noise mitigation measures including building setbacks, alternative site design techniques, and alternative building orientation layouts shall be employed in lieu of sound walls to miti- gate noise impacts. Sound walls may be used if there are no other reasonable mitigation measures available or all reasonable mitigation measures do not satisfactorily reduce noise levels to acceptable levels. The Municipal Code, Title 18, Development Code, further includes ordi- nances governing mobile and stationary noise sources that are applicable to the proposed project as outlined below. ¤ 18.44.050 - Residential Interior Noise Standards: Single-family and multi- family residential development shall be designed and constructed to com- ply with the interior noise standards of this Section. A. Interior Noise Standard: Whenever a new single-family or multi- family dwelling unit is proposed on a parcel where the existing exte- rior ambient noise level may exceed 60 dB(A) CNEL, the land use permit application shall include an acoustical analysis showing the dwelling unit has been designed to limit intruding noise to an interi- TOWN OF TRUCKEE CANYON SPRINGS DRAFT EIR NOISE 4.11-11 or CNEL of 45 dB(A), in compliance with California Code of Regu- lations Title 24, Part 2. B. Residential Development Affected by Aircraft Noise: Land use per- mit applications for residential structures proposed within the Air- port 55 dB(A) CNEL contour shall comply with the provisions of Section 18.64.060 (Airport Noise Zones). C. Noise Mitigation Measures: Whenever interior noise levels may ex- ceed 45 dB(A) CNEL, residential developments shall incorporate the following noise mitigation measures, where appropriate: 1. Increase the distance between the noise source and the receiver; 2. Locate bedrooms on the side of the structure away from major public rights-of-way; and/or 3. Locate land uses not sensitive to noise (e.g., garages, maintenance facilities, parking lots, utility areas, etc.) between the noise source and the receiver. D. Noise Barrier Standards: The minimum acceptable surface weight for a noise barrier is four pounds per square foot (equivalent to three- fourths inch plywood). Noise barriers shall interrupt the line-of- sight between the noise source and the receiver. The barrier shall be of a continuous material which is resistant to sound and may includ- ing the following: 1. Earth berm or a combination of earth berm with concrete block; or, 2. Masonry block; or, 3. Precast concrete. ¤ 18.44.070 – Exceptions. A. Construction: The provisions of this section shall not apply to noise sources associated with non-single family residential construction, provided the activities do not take place before 7:00 a.m. or after 9:00 p.m. on any day except Sunday, or before 9:00 a.m. or after 6:00 p.m. on Sunday. The review authority may impose further limitations on T OWN OF TRUCKEE CANYON SPRINGS DRAFT EIR NOISE 4.11-12 the hours of construction or other measures to mitigate significant noise impacts on sensitive uses. G. Public Transportation Facilities. The provisions of this section shall not apply to any airports, railroad facilities including but not limited to trains, rolling stock, and railroad equipment, publicly owned roads and rights-of-way, or other similar facilities. C. Existing Conditions The following section describes the existing noise environment and identifies primary noise sources in each of the component areas of the proposed subdi- vision area. 1. Existing Conditions The project noise environment can be characterized as a typical rural envi- ronment and has not changed substantially in the last several years. There- fore, the ambient noise measurements conducted in 2006 by J.C. Brennan & Associates, Inc. are an accurate representation of the existing noise environ- ment in the project vicinity. The results of their noise monitoring effort are documented in the Canyon Springs Subdivision Draft EIR, dated April 2007.1 According to their documentation, in May 2006, continuous 24-hour noise level measurements were conducted on the proposed project site. In addition, short-term noise level measurements were also conducted on the site and in the vicinity of the site at four locations. Figure 4.11-1 shows the locations of all noise measurement sites. Table 4.11-6 shows the results of the noise measurement data. An analysis of this data was used to determine the overall daily noise levels on the project 1 The 2007 Draft EIR prepared for the project site by Quad Knopf was com- pleted and comments were provided by the public and interested agencies; however, no Final EIR was prepared and the 2007 Draft EIR was not certified. Comments submitted on the 2007 Draft EIR were taken into consideration for the preparation of this Draft EIR. TOWN OF TRUCKEE CANYON SPRINGS DRAFT EIR NOISE NOISE MEASUREMENT MAP FIGURE 4.11-1 Source: SCO Planning, Engineering & Surveying, April 2011. J.C. Brennan & Associates, 2006 / Quad Knopf, 2007.4000 800 FeetNORTH R R Martis Peak Road Main Access Point Edinburgh Drive Gated Access Short term noise measurement site 24 hour continuous noise measurement siteA# A 1 2 3 4 T OWN OF TRUCKEE CANYON SPRINGS DRAFT EIR NOISE 4.11-14 TABLE 4.11-6 AMBIENT NOISE MONITORING RESULTS, MAY 23-24, 2006 Site Measured Ldn/CNEL (dBA) Average Hourly Daytime (7:00 am – 10:00 pm) Leq (dBA) Lmax (dBA) A 45.8 45.4 51.4 1 NA 41.6 48.4 2 NA 42.6 56.1 3 NA 40.1 49.6 4 NA 40.3 52.9 Source: J.C. Brennan & Associates, Inc., April 2007. site for comparison to the Town’s land use compatibility standards. Based upon the noise measurements, the proposed project site and surrounding area can be characterized as fairly quiet with documented noise levels ranging from 40 dBA to 45 dBA Leq, and 45.8 dBA CNEL. Existing noise sources included distant trains, local roadway traffic, and aircraft operations at the Tahoe Truckee Airport. 2. Existing Aircraft Noise Sources While aircraft noise is occasionally audible within the project vicinity, the project does not lie within the noise influence area of the Truckee-Tahoe Air- port. Truckee-Tahoe Airport is located over 3.5 miles southwest of the pro- ject site. According to the future airport noise contours (Figure 2B of the Truckee Tahoe Airport Land Use Compatibility Plan)2 the project site would lie outside of the 55 dBA CNEL airport noise contour. The noise contours rep- resent the points beyond which airport-related noise would attenuate to be- low the indicated noise level. These contours reflect generalized noise projec- tions, and do not take into account site specific topography, natural vegeta- tion, site orientation or other localized factors. 2 Truckee Tahoe Airport Land Use Compatibility Plan, December 2, 2004. TOWN OF TRUCKEE CANYON SPRINGS DRAFT EIR NOISE 4.11-15 3. Existing Traffic Noise Sources Vehicular traffic is the primary noise source in the project vicinity. The exist- ing traffic noise levels along select roadway segments in the study area are listed in Table 4.11-7. The Federal Highway Administration (FHWA) High- way Traffic Noise Prediction Model (RD-77-108) was used to evaluate traffic- related noise conditions along segments of Glenshire Drive and Martis Peak Road in the project vicinity. These existing roadways would handle all the trips that access the project site. The project access drive as well as all internal roadways would be constructed with implementation of the project. The traffic noise model requires various data inputs, including traffic volumes, vehicle mix, vehicle speed, and roadway geometry to compute typical equiva- lent noise levels during daytime, evening, and nighttime hours. Traffic vol- umes were obtained from the traffic study prepared for the project by LSC Transportation Consultants, Inc.3 The resultant noise levels were weighted and summed over 24-hour periods to determine the CNEL values. Existing noise levels along these roadway segments (at 50 feet from the centerline of the outermost travel lane) range from 51.7 dBA CNEL to 64.9 dBA CNEL. The traffic noise model printouts are included in Appendix I, Traffic Data, of this Draft EIR. D. Standards of Significance The proposed project would have a significant impact with regard to noise if it would result in the following: ¤ Exposure of persons to or generation of noise levels in excess of standards established in the local General Plan or noise ordinance, or applicable standards of other agencies. ¤ Exposure of persons to or generation of excessive groundborne vibration or groundborne noise levels. 3 LSC Transportation Consultants, Inc., Canyon Springs Traffic Impact Analysis, 2011 (See Appendix I of this Draft EIR). T OWN OF TRUCKEE CANYON SPRINGS DRAFT EIR NOISE 4.11-16 TABLE 4.11-7 EXISTING TRAFFIC NOISE LEVELS Roadway Segment ADTa Center- line to 70 CNEL (Feet) Center- line to 65 CNEL (Feet) Center- line to 60 CNEL (Feet) CNEL (dBA) 50 Feet From Centerline of Outer- Most Lane Glenshire Drive – Old State Route 40 to Dorchester Drive 6,300 < 50 b 55 118 64.9 Glenshire Drive – Dorchester Drive to Somerset Drive 4,000 < 50 < 50 87 62.9 Glenshire Drive – Somerset Drive to Martis Peak Road 2,900 < 50 < 50 70 61.5 Glenshire Drive – Martis Peak Road to Hirschdale Road 3,100 < 50 < 50 74 61.8 Glenshire Drive – Hirschdale Road to I–80 ramps 3,200 < 50 < 50 75 61.9 Martis Peak Road – east of Glenshire Drive 300 < 50 < 50 < 50 49.0 a Average Daily Traffic. b Traffic noise within 50 feet of the roadway centerline requires site-specific analysis. Source: LSA Associates Inc., August 2011. ¤ A substantial permanent increase in ambient noise levels in the project vicinity above levels existing without the project. ¤ A substantial temporary or periodic increase in ambient noise levels in the project vicinity above levels existing without the project. ¤ For a project located within an airport land use plan or, where such a plan has not been adopted, within 2 miles of a public airport or public use airport, would the project expose people residing or working in the project area to excessive noise levels. TOWN OF TRUCKEE CANYON SPRINGS DRAFT EIR NOISE 4.11-17 ¤ For a project within the vicinity of a private airstrip, would the project expose people residing or working in the project area to excessive noise levels. E. Impact Discussion This section explains what the project’s potential impacts are, and it tells which impacts would actually occur, and why. 1. Project Impacts a. Exposure of persons to or generation of noise levels in excess of standards established in the local General Plan or noise ordinance, or applicable standards of other agencies. i. Traffic Noise Impacts. The FHWA highway traffic noise prediction model (FHWA RD-77-108) was used to evaluate traffic-related noise conditions in the vicinity of the project area. The resultant noise levels were weighed and summed over a 24-hour period in order to determine the CNEL values. The existing and future traf- fic volumes for roadway segments in the project vicinity were used in the traffic noise impact analysis. Table 4.11-8 shows the 2011 Plus Project Traffic Noise Levels along modeled roadway segments in the project area. Tables 4.11-9 and 4.11-10 show the predicted traffic noise levels for the year 2031 without and with the project, respectively. A significant impact would occur for proposed on-site noise sensitive land uses if the cumulative (2031) traffic noise levels would exceed the Town’s normally acceptable standards for new residential development according to land use shown in Table 4.11-3. Ambient noise levels greater than 60 dBA CNEL are in excess of the Town’s standards for normally acceptable noise environments for new residential development, such as that proposed under the project. TOWN OF TRUCKEE CANYON SPRINGS DRAFT EIR NOISE 4.11-18 TABLE 4.11-8 2011 PLUS PROJECT TRAFFIC NOISE LEVELS Roadway Segment ADTa Centerline to 70 CNEL (Feet) Centerline to 65 CNEL (Feet) Centerline to 60 CNEL (Feet) 50 Feet from Centerline of Outermost Lane CNEL (dBA) Increase from Existing Conditions Glenshire Drive – Old State Route 40 to Dorchester Drive 7,000 < 50 b 59 126 65.3 0.4 Glenshire Drive – Dorchester Drive to Somerset Drive 4,800 < 50 < 50 98 63.7 0.8 Glenshire Drive – Somerset Drive to Martis Peak Road 3,900 < 50 < 50 86 62.8 1.3 Glenshire Drive – Martis Peak Road to Hirschdale Road 4,700 < 50 < 50 97 63.6 1.8 Glenshire Drive – Hirschdale Road to I-80 ramps 4,800 < 50 < 50 98 63.7 1.8 Martis Peak Road – East of Glenshire Drive 2,800 < 50 < 50 < 50 58.7 9.7 Project Main Access Road – South of Martis Peak Road 2,800 < 50 < 50 < 50 55.2 NA Note: NA = Not applicable as there is no existing roadway to which to make a comparison. a Average Daily Traffic. b Traffic noise within 50 feet of the roadway centerline requires site-specific analysis. Source: LSA Associates Inc., August 2011. TOWN OF TRUCKEE CANYON SPRINGS DRAFT EIR NOISE 4.11-19 TABLE 4.11-9 2031 WITHOUT PROJECT TRAFFIC NOISE LEVELS Roadway Segment ADT Centerline to 70 CNEL (Feet) Centerline to 65 CNEL (Feet) Centerline to 60 CNEL (Feet) CNEL (dBA) 50 Feet from Centerline of Outermost Lane Glenshire Drive - Old State Route 40 to Dorchester Drive 8,600 < 50 67 145 66.2 Glenshire Drive - Dorcester Drive to Somerset Drive 5,600 < 50 51 109 64.4 Glenshire Drive - Somerset Drive to Martis Peak Road 3,100 < 50 < 50 74 61.8 Glenshire Drive - Martis Peak Road to Hirschdale Road 3,100 < 50 < 50 74 61.8 Glenshire Drive - Hirschdale Road to I-80 ramps 5,200 < 50 < 50 104 64.0 Martis Peak Road - east of Glenshire Drive 300 < 50 < 50 < 50 49.0 Project Main Access Road - south of Martis Peak Road NA NA NA NA NA Source: LSA Associates Inc., August 2011. TOWN OF TRUCKEE CANYON SPRINGS DRAFT EIR NOISE 4.11-20 TABLE 4.11-10 2031 PLUS PROJECT TRAFFIC NOISE LEVELS Roadway Segment ADT Centerline to 70 CNEL (Feet) Centerline to 65 CNEL (Feet) Centerline to 60 CNEL (Feet) 50 Feet from Centerline of Outermost Lane CNEL (dBA) Increase from Without Project Conditions Glenshire Drive - Old State Route 40 to Dorchester Drive 9,400 < 50 72 154 66.6 0.4 Glenshire Drive - Dorchester Drive to Somerset Drive 6,500 < 50 56 120 65.0 0.6 Glenshire Drive - Somerset Drive to Martis Peak Road 4,000 < 50 < 50 87 62.9 1.1 Glenshire Drive - Martis Peak Road to Hirschdale Road 4,700 < 50 < 50 97 63.6 1.8 Glenshire Drive - Hirschdale Road to I-80 ramps 6,700 < 50 57 123 65.1 1.1 Martis Peak Road - east of Glenshire Drive 6,700 < 50 < 50 81 62.5 13.5 Project Main Access Road - south of Martis Peak Road 6,700 < 50 < 50 < 50 59.0 NA Source: LSA Associates Inc., August 2011. TOWN OF TRUCKEE CANYON SPRINGS DRAFT EIR NOISE 4.11-21 Although the traffic analysis did not generate vehicle trip calculations for the project’s access (and primary internal) road, for the purposes of this analysis (and to provide an environmentally conservative analysis) it was assumed that the total (background plus project) trips for Martis Peak Road would also be the maximum trips for the primary access road. Per the Town Municipal Code Section 18.05.020, the speed limit on all Town local streets is 25 miles per hour. Thus, using the same traffic volume as Martis Peak Road but with a traffic speed of 25 mph, the resulting traffic noise levels for the year 2031 would range up to 59 dBA CNEL at 50 feet from the centerline of the outer- most travel lane of the project’s access and primary internal road. This noise level is within the Town’s “normally acceptable” range for new residential development. Therefore, traffic noise levels would have a less-than-significant impact in the project area. The traffic noise model printouts for all calculations, including those for the project’s access road, are included in Appendix I of this Draft EIR. ii. Stationary Sources Noise Impacts. Proposed project on-site uses could contain stationary noise sources such as mechanical equipment (e.g. air conditioning and heating units) and landscap- ing and maintenance equipment. The use of these types of equipment would be potential point sources of noise that could affect noise-sensitive receptors in the project vicinity. However, proposed residential units would be located over 500 feet from the closest existing noise sensitive receptors. At this dis- tance, noise levels from periodic use of project-related stationary equipment would not result in a perceptible increase in ambient noise levels, nor would they result in an exceedance of the existing ambient noise levels at nearby sensitive land uses. Therefore, noise levels from project-related stationary noise sources would result in a less-than-significant impact on off-site sensitive receptors. TOWN OF TRUCKEE CANYON SPRINGS DRAFT EIR NOISE 4.11-22 b. Exposure of persons to or generation of excessive groundborne vibration or groundborne noise levels. Human perception to vibration starts at levels as low as 67 VdB and some- times lower. Annoyance due to vibration in residential settings starts at ap- proximately 70 VdB. In extreme cases, excessive groundborne vibration has the potential to cause structural damage to buildings. The damage threshold for buildings considered of particular historical significance or that are partic- ularly fragile structures is approximately 96 VdB; the damage threshold for other structures is 100 VdB.4 Common sources of ground-borne vibration include construction activities such as blasting, pile driving, and operating heavy earth moving equipment. However, it is anticipated that construction of the project will not employ pile driving as a construction method. Typical groundborne vibration levels measured at a distance of 50 feet from heavy construction equipment in full operation, such as bulldozers or other heavy tracked equipment, range up to approximately 94 VdB. This is below the damage threshold for historic or fragile buildings. Furthermore, compliance with all of Truckee’s established standard construction noise control measures would reduce construction- related groundborne vibration impacts to a less-than-significant level. No permanent noise sources that would expose persons to excessive ground borne vibration or noise levels are proposed as part of the project. Therefore, implementation of the proposed project would have a less-than-significant im- pact in the permanent exposure of persons within or around the project site to excessive ground borne vibration. c. A substantial permanent increase in ambient noise levels in the project vicinity above levels existing without the project. A significant impact on off-site sensitive receptors would occur if project re- lated traffic noise levels would result in a substantial permanent increase of 5 dBA if the existing ambient noise level is below 60 dBA, or an increase of 4 Harris, C.M., 1998. Handbook of Acoustical Measurements and Noise Control. TOWN OF TRUCKEE CANYON SPRINGS DRAFT EIR NOISE 4.11-23 3 dBA or greater if the ambient noise level is between 60 and 65 dBA, or an increase by more than 1.5 dBA if the ambient noise level in the project vicini- ty is greater than 65 dBA. Modeling results indicate that only one modeled roadway segment would experience an increase in project-related traffic noise levels of more than 5 dBA. The roadway segment of Martis Peak Road east of Glenshire Drive would experience traffic noise levels of up to 58.7 dBA CNEL under the 2011 plus project traffic conditions, representing an increase of 9.7 dBA compared to conditions without the project. Under 2031 with project traffic condi- tions, this roadway segment would experience traffic noise levels of up to 62.5 dBA CNEL, representing an increase of 13.4 dBA compared to conditions without the project. However, there are no existing sensitive land uses along this roadway segment. The closest residential property to this roadway seg- ment is located over 100 feet west of Martis Peak Road, the residential prop- erty in the southwest quadrant of the Glenshire Drive and Martis Peak Road intersection. At a distance of 100 feet, noise levels from traffic on Martis Peak Road would attenuate to below 57 dBA CNEL. However, the closest resi- dential property fronts Glenshire Drive and is exposed to noise levels from traffic on Glenshire Drive of up to 61.5 dBA CNEL under existing condi- tions. Therefore, noise levels from traffic on Martis Peak Road would not result in an increase in traffic noise levels at this closest sensitive receptor. Therefore, implementation of the proposed project would result in a less-than- significant permanent increase in ambient noise levels impacting any sensitive land use in the project vicinity. d. A substantial temporary or periodic increase in ambient noise levels in the project vicinity above levels existing without the project. Noise levels from grading and other construction activities associated with build out of the project may range up to 91 dBA Lmax at the closest off-site sensitive receptors for very limited times when construction occurs near the project’s boundary. Short-term noise impacts would result from excavation, grading, and erecting of buildings within the project area during construction TOWN OF TRUCKEE CANYON SPRINGS DRAFT EIR NOISE 4.11-24 of proposed projects. Construction-related short-term noise levels would be higher than existing ambient noise levels in the project area but would no longer occur once construction is completed. Two types of short-term noise impacts could occur during construction with- in the project area. First, construction crew commutes and the transport of construction equipment and materials to construction sites within the project area would incrementally increase noise levels on access roads leading to the sites. Although there would be a relatively high single-event noise exposure potential causing intermittent noise nuisance (passing trucks at 50 feet would generate up to a maximum of 86 dBA Lmax), the effect on longer term (hour- ly or daily) ambient noise levels would be small. Therefore, short-term con- struction related impacts associated with worker commute and equipment transport to construction sites within the project area would be less than sig- nificant. The second type of short-term noise impact is related to noise generated dur- ing excavation, grading, and erection of buildings on sites within the project area. Construction is completed in discrete steps, each of which has its own mix of equipment and, consequently, its own noise characteristics. These various sequential phases would change the character of the noise generated and, therefore, the noise levels surrounding the site as construction progress- es. Despite the variety in the type and size of construction equipment, simi- larities in the dominant noise sources and patterns of operation allow con- struction related noise ranges to be categorized by work phase. Table 4.11-11 lists typical construction equipment noise levels recommended for noise im- pact assessments, based on a distance of 50 feet between the equipment and a noise receptor. The site preparation phase, which includes excavation and grading of the site, tends to generate the highest noise levels, because the nois- iest construction equipment is earth moving equipment. Earth moving equipment includes excavating machinery such as backhoes, bulldozers, drag- lines, and front loaders. Earth moving and compacting equipment includes compactors, scrapers, and graders. Typical operating cycles for these TOWN OF TRUCKEE CANYON SPRINGS DRAFT EIR NOISE 4.11-25 TABLE 4.11-11 TYPICAL CONSTRUCTION EQUIPMENT MAXIMUM NOISE LEVELS Type of Equipment Range of Maximum Sound Levels (dBA at 50 ft) Suggested Maximum Sound Levels for Analysis (dBA at 50 ft) Pile Drivers 81 to 96 93 Rock Drills 83 to 99 96 Jackhammers 75 to 85 82 Pneumatic Tools 78 to 88 85 Pumps 68 to 80 77 Scrapers 83 to 91 87 Haul Trucks 83 to 94 88 Electric Saws 66 to 72 70 Portable Generators 71 to 87 80 Rollers 75 to 82 80 Dozers 85 to 90 88 Tractors 77 to 82 80 Front-End Loaders 86 to 90 88 Hydraulic Backhoe 81 to 90 86 Hydraulic Excavators 81 to 90 86 Graders 79 to 89 85 Air Compressors 76 to 89 85 Trucks 81 to 87 85 Source: Bolt, Beranek & Newman, 1987. Noise Control for Buildings and Manufacturing Plants. TOWN OF TRUCKEE CANYON SPRINGS DRAFT EIR NOISE 4.11-26 types of construction equipment may involve 1 or 2 minutes of full-power operation followed by three or four minutes at lower power settings. During the construction phase, equipment such as bulldozers, scrapers, load- ers, graders, water trucks, and other trucks will be used. As shown in Table 4.11-11, the typical maximum noise level generated by backhoes is assumed to be 86 dBA Lmax at 50 feet from the operating equipment. The maximum noise level generated by bulldozers is approximately 88 dBA Lmax at 50 feet. The maximum noise level generated by trucks is approximately 85 dBA Lmax at 50 feet from these vehicles. Each doubling of the sound sources with equal strength would increase the noise level by 3 dBA. Assuming each piece of construction equipment operates at some distance apart from the other equipment, the worst-case combined noise level during the construction phase would be 91 dBA Lmax at a distance of 50 feet from an active construction ar- ea. The closest existing sensitive receptors would be the residential land uses lo- cated along the east end of Edinburgh Drive near the southwest portion of the project area. These residences would potentially be exposed to construc- tion noise levels of up to 91 dBA Lmax during construction of the extension of Edinburgh Drive (for the emergency access roadway) would occur. Other noise sensitive receptors would include residential land uses along Regency Circle and a portion of Courtney Lane that would be exposed to noise during installation of the off-site water main. These residences would potentially be exposed to construction noise levels of up to 91 dBA Lmax if multiple pieces of earth moving equipment operate simultaneously on the roadway adjacent to their property. The operation of heavy earth moving equipment related to construction of the proposed project would result in substantial temporary or periodic in- crease in ambient noise levels in the project vicinity above levels existing without the project. However, through mandatory regulatory compliance with the Town’s standards including Town’s General Plan Policy P3.13 and Development Code Section 18.44.070, project related noise impacts resulting TOWN OF TRUCKEE CANYON SPRINGS DRAFT EIR NOISE 4.11-27 from construction would be less than significant and no mitigation measures are required. e. For a project located within an airport land use plan or, where such a plan has not been adopted, within 2 miles of a public airport or public use airport, would the project expose people residing or working in the project area to excessive noise levels. Aircraft related noise would be audible at noise sensitive land uses on the pro- ject site. However, the project site is located approximately 3.5 miles from the Truckee-Tahoe Airport, and lies well outside of the 55 dBA CNEL air- port noise contour. Therefore, due to the distance from and the flight path orientation to the airport, aircraft related noise impacts would have a less- than-significant impact on noise sensitive development within the project area. f. For a project within the vicinity of a private airstrip, would the project expose people residing or working in the project area to excessive noise levels. The Truckee-Tahoe Airport, which is the closest airport, is located approxi- mately 3.5 miles southwest of the project site. The proposed project would not be located in an airport land use plan or within 2 miles of a private air- strip. Therefore, implementation of the proposed project would have a less- than-significant impact on the exposure of persons within the project site to excessive aircraft-related noise levels. 2. Cumulative Impacts This section analyzes potential noise impacts that could occur from a combi- nation of the project with the Town buildout identified in the Town of Truck- ee 2025 General Plan and reasonably foreseeable projects in the surrounding area. The geographic scope of this analysis is taken as the Town of Truckee sphere of influence (SOI), as defined in the Town of Truckee 2025 General Plan and reasonably foreseeable projects in the surrounding area. Therefore, as described in Chapter 4, Environmental Evaluation, of this Draft EIR, the Boca Quarry Expansion project in Nevada County, when considered with the project and the Town buildout of the Town of Truckee 2025 General Plan TOWN OF TRUCKEE CANYON SPRINGS DRAFT EIR NOISE 4.11-28 could result in cumulative environmental impacts. The Boca Quarry Expan- sion project site is approximately 2.5 miles northeast of the project site and north of Interstate 80 and noise generated from this project would not impact the project area. Cumulative noise impacts associated with implementation of the proposed project would primarily result from project-related traffic noise sources. As shown in the discussion above in Section E, Traffic Noise Impacts, implemen- tation of the proposed project would result in projected traffic noise levels along the project’s primary access road of up to 59 dBA CNEL at 50 feet from the centerline of the outermost travel lane under future 2031 conditions with the project which is within the Town’s “normally acceptable” range for new residential development. Therefore, no on-site significant exterior noise impacts would occur from cumulative (2031) traffic noise levels. A cumulative impact would also occur if there would be any increase in am- bient noise levels at existing sensitive receptors in the project vicinity that are currently exposed to noise levels above the Town’s conditionally acceptable threshold for that type of land use. As discussed above, the roadway segment of Martis Peak Road east of Glenshire Drive would experience traffic noise levels of up to 58.7 dBA CNEL under the 2011 plus project traffic conditions, representing an increase of 9.7 dBA compared to conditions without the pro- ject. Under 2031 with project traffic conditions, which include the Bocca Quarry project, this roadway segment would experience traffic noise levels of up to 62.5 dBA CNEL, representing an increase of 13.4 dBA compared to conditions without the project. However, there are no existing sensitive land uses along this roadway segment. Therefore, no existing traffic noise levels exceed the Town’s conditionally acceptable threshold of 65 dBA CNEL for residential land uses. Therefore, the project would have a less-than-significant increase in traffic noise levels under cumulative conditions with implementa- tion of the proposed project. TOWN OF TRUCKEE CANYON SPRINGS DRAFT EIR NOISE 4.11-29 F. Impacts and Mitigation Measures Project and cumulative impacts related to noise would be less than significant and no mitigation measures are required. TOWN OF TRUCKEE CANYON SPRINGS DRAFT EIR NOISE 4.11-30