5.11 NOISE EXISTING CONDITIONS Fundamentals of Sound

Transcription

1 5.11 NOISE This section evaluates the potential environmental effects related to noise associated with the proposed Project EXISTING CONDITIONS Fundamentals of Sound Sound is technically described in terms of loudness and frequency. The loudness of sound or noise, two terms that are used interchangeably throughout this section, is measured using a logarithmic scale with 10 as the base. The standard unit of sound measurement is the decibel (db), or db scale, which describes the physical intensity of the pressure vibrations that make up any sound. The decibel scale sets the hearing threshold as 0 db. The frequency of the sound is related to the pressure vibration, which is measured in hertz (Hz), which is measured in cycles per second. The human ear can detect a wide range of frequencies and sound pressure levels. The subjective audible sound pressure range is from 0 db to 140 db. The just-noticeable difference is typically around 1 db for sound level. The hearing thresholds show considerable variability from individual to individual, with a standard variation among individuals of about 5 db. Human ears can detect not only changes in overall sound pressure level, but also detect sound with a sound pressure well below the background noise level. Studies have shown that sound is perceived to be twice as loud if the sound level increases by 10 db. Similarly, a 20 db increase in the sound level is perceived as four times as loud by the normal human ear. In response to this sensitivity of the human ear to different frequencies, the A-weighted noise level, referenced in units of db(a), was developed to better correspond with subjective judgment of sound levels experienced by individuals. A doubling of sound energy results in a 3 db(a) increase in sound, which means that a doubling of sound wave energy (e.g., doubling the volume of traffic on a roadway) would result in a barely perceptible change in sound level. In general, changes in a noise level of less than 3 db(a) are not typically noticed by the human ear. 1 Changes from 3 to 5 db(a) may be noticed by some individuals who are extremely sensitive to changes in noise. An increase of greater than 5 db(a) is readily noticeable, while the human ear perceives a 10 db(a) increase in sound level to be a doubling of sound volume. 1 US Department of Transportation (USDOT), Federal Highway Administration (FHA), Fundamentals and Abatement of Highway Traffic Noise (Springfield, VA: USDOT FHA,, 1980), 81. Meridian Consultants ATV Adventure Trails of the Eastern Sierra

2 Noise sources can generally be categorized as one of two types: (1) point sources, such as stationary mechanical equipment; and (2) line sources, such as a roadway. Noise levels generated by a variety of activities are shown in Figure , Common Noise Levels. Sound generated by a point source typically diminishes or attenuates at a rate of 6 db(a) for each doubling of distance from the source to the receptor at acoustically hard sites and at a rate of 7.5 db(a) at acoustically soft sites. A hard, or reflective, site consists of asphalt, concrete, or very hard-packed soil, which does not provide any excess ground-effect attenuation, while an acoustically soft site consists of normal earth or most ground with vegetation. 2 As an example, a 60 db(a) noise level measured at 50 feet from a point source at an acoustically hard site would be 54 db(a) at 100 feet from the source and 48 db(a) at 200 feet from the source. Noise from the same point source at an acoustically soft site would be 52.5 db(a) at 100 feet and 45 db(a) at 200 feet from the source. Sound generated by a line source typically attenuates at a rate of 3 db(a) and 4.5 db(a) per doubling of distance from the source to the receptor for hard and soft sites, respectively. 3 Man-made or natural barriers can also attenuate sound levels. Solid walls and berms may reduce noise levels by 5 to 10 db(a). 4 Sound levels from a source may also be attenuated 3 to 5 db(a) by the first row of houses and 1.5 db(a) for each additional row of houses in a residential neighborhood. The minimum attenuation of exterior to interior noise provided by typical residential and commercial buildings in California is 17 db(a) with open windows and 25 db(a) with closed windows. Environmental Noise Noise level increases are used to determine the effect of noise in environmental settings. Many methods have been developed for evaluating community noise to account for, among other things: The variation of noise levels over time The influence of periodic individual loud events The community response to changes in the community noise environment Table , Noise Descriptors, identifies various noise descriptors developed to measure sound levels over different periods of time. 2 USDOT FHA, Fundamentals and Abatement of Highway Traffic Noise (1980), USDOT FHA, Fundamentals and Abatement of Highway Traffic Noise (1980), USDOT FHA, Fundamentals and Abatement of Highway Traffic Noise (1980), 18. Meridian Consultants ATV Adventure Trails of the Eastern Sierra

3 Table Noise Descriptors Decibel (db) Term A-weighted decibel (db[a]) Equivalent sound level (Leq) Day-Night Average Sound Level (Ldn) Community noise equivalent level (CNEL) Sound pressure level Ambient noise Definition The unit for measuring the volume of sound equal to 10 times the logarithm (base 10) of the ratio of the pressure of a measure sound to a reference pressure. A sound measurement scale that adjusts the pressure of individual frequencies according to human sensitivities. The scale accounts for the fact that the region of highest sensitivity for the human ear is between 2,000 and 4,000 cycles per second (hertz). The sound level containing the same total energy as a time varying signal over a given time period. The Leq is the value that expresses the time averaged total energy of a fluctuating sound level. Leq can be measured over any time period, but is typically measured for 1-minute, 15-minute, 1-hour, or 24-hour periods. The average sound exposure over a 24-hour period. Ldn values are calculated from hourly Leq values, with the Leq values for the nighttime period (10:00 PM to 7:00 AM) increased by 10 db to reflect their greater disturbance potential. A rating of community noise exposure to all sources of sound that differentiates between daytime, evening, and nighttime noise exposure. These adjustments add 5 db(a) for the evening (7:00 PM to 10:00 PM) and 10 db(a) for the night (10:00 PM to 7:00 AM).These penalties are applied to account for increased noise sensitivity during the evening and nighttime hours. The logarithmic effect of adding these penalties to the 1-hour Leq measurements typically results in a CNEL measurement that is within approximately 3 db(a) of the peak-hour Leq. The sound pressure is the force of sound on a surface area perpendicular to the direction of the sound. The sound pressure level is expressed in decibels (db). The level of noise that is all encompassing within a given environment, being usually a composite of sounds from many and varied sources both near to and far from the observer. No specific source is identified in the ambient noise. Source: California Department of Transportation, Technical Noise Supplement; A Technical Supplement to the Traffic Noise Analysis Protocol (Sacramento, CA: November 2009), N51 N54. Health Effects of Noise Human response to sound is highly individualized. Annoyance is the most common issue associated with community noise levels. Many factors influence the response to noise, including the character of the noise, the variability of the sound level, the presence of tones or impulses, and the time of day of the occurrence. Additionally, nonacoustic factors, such as individual opinion of the noise source, the ability to adapt to the noise, the attitude toward the source and those associated with it, and the predictability of the noise, all influence the response to noise. Thus, reaction to noise is highly subjective, with the perceived effect of a particular noise varying widely among individuals in a community. Meridian Consultants ATV Adventure Trails of the Eastern Sierra

4 The effects of noise can be grouped into three general categories: Subjective effects of annoyance, nuisance, and dissatisfaction Interference with activities such as speech, sleep, and learning Physiological effects such as hearing loss Noise-induced hearing loss usually takes years to develop. Hearing loss is one of the most obvious and easily quantifiable effects of excessive exposure to noise. While the loss may be temporary at first, it can become permanent after continued exposure. When combined with hearing loss associated with aging, the amount of hearing loss directly due to the environment is difficult to quantify. Although the major cause of noise-induced hearing loss is occupational, nonoccupational sources may also be a factor. Noise can mask important sounds and disrupt communication between individuals in a variety of settings. This process can cause anything from a slight irritation to a serious safety hazard, depending on the circumstance. Noise can disrupt both face-to-face and telephone communications, as well as the enjoyment of music and television in the home. Interference with communication has proved to be one of the most important components of noise-related annoyance. Noise-induced sleep interference is one of the critical components of community annoyance. Sound level, frequency distribution, duration, repetition, and variability can make it difficult to fall asleep and may cause momentary shifts in the natural sleep pattern or level of sleep. It can produce short-term effects, with the possibility of more serious effects on health, if it continues over long periods. Annoyance can be defined as the expression of negative feelings resulting from interference with activities, as well as the disruption of one s peace of mind and the enjoyment of one s environment. The consequences of noise-induced annoyance are privately held dissatisfaction, publicly expressed complaints to authorities, and potential adverse health effects, as discussed previously. Existing Noise Environment The Project area is located primarily within the upper Owens River Valley portion of Inyo County. Land uses include residential, commercial, open space, recreational, and grazing. Noise sources can be grouped into two categories: mobile sources, which are noise producers that move within the County (these include vehicle traffic on highway and roads and aircraft noise from military operations); and noise from general and commercial aviation. Primary stationary sources in the County include mining, industrial, commercial, and utility land uses. Meridian Consultants ATV Adventure Trails of the Eastern Sierra

5 Roadways, in particular federal (US 395) and State highways (SR 168), are a source of ambient noise in Inyo County, considering that most developed communities (City of Bishop and surrounding areas and unincorporated communities including Lone Pine, Independence, and Big Pine) are located adjacent to these corridors. Noise generated from vehicles is governed primarily by the number of vehicles, types of vehicles (the mix of automobiles, trucks, OHVs and other large vehicles), and speed. Table , Traffic Noise Levels along US 395, summarizes the daily traffic volumes, the predicted Ldn noise level at 100 feet from the roadway centerline, and the distance from the roadway centerline to the 55, 65, and 70 db Ldn contours for current conditions. Given the size of the County and the Project area, this table is used to represent the noise contour information for existing conditions requested by state planning guidelines for noise elements. Ambient Noise Representative noise measurements were collected at sites throughout the Project area on March 13, 2014, between 6:45 AM and 1:00 PM to document the ambient noise environment. Noise measurements were conducted over 15-minute intervals in accordance with American National Standards Institute (ANSI) standards using Larson Davis Laboratories (LDL) Model 831, precision integrating sound level meter (SLM). The SLM was calibrated before and after use with an LDL Model Cal200 acoustical calibrator to ensure measurement accuracy. The equipment meets all pertinent specifications of the ANSI standards for Type 1 SLMs (ANSI S [R2006]). Meteorological conditions during the measurement periods were favorable, with clear skies, temperatures ranging from 65 F to 75 F, and light winds ranging from 3 to 8 miles per hour (mph). Noise measurement locations for Bishop are shown in Figure , Noise Measurement Locations for Bishop Site. Noise measurement locations for Aberdeen are shown in Figure , Noise Measurement Locations for Aberdeen Site. Noise measurement locations for Big Pine are shown in Figure , Noise Measurement Locations for Big Pine Site. Noise measurement locations for Independence are shown in Figure , Noise Measurement Locations for Independence Site. Noise measurement locations for Lone Pine are shown in Figure , Noise Measurement Locations for Lone Pine Site. The ambient noise measurement and its proximity to sensitive receptors for each location are shown on Table , Ambient Noise Levels. Meridian Consultants ATV Adventure Trails of the Eastern Sierra

6 Roadway/Segment Daily Traffic Volume Table Traffic Noise Levels along US 395 Percent Truck Traffic Ldn at 100 feet Distance (feet) to 70 Ldn Contour Distance (feet) to 65 Ldn Contour Distance (feet) to 55 Ldn Contour Bishop 12,300 8% Big Pine 6,800 10% Independence 6,000 11% Lone Pine 6,300 11% Olancha 5,500 11% Source: Inyo County General Plan, Technical Background Report (2001). Measurement Location Minimum Maximum Table Ambient Noise Levels Average Noise Level Leq db(a) Nearest Sensitive Receptor (Distance from center of the road) Location ft. Location ft. Location ft. Location ft. Location ft. Location ft. Location ft. Location ft. Location ft. Location ft. Location ft. Location ft. Location ft. Location ft. Note: Noise monitoring was conducted over 15-minute intervals on March 13, 2014, between 6:45 AM and 1:00 PM. Noise measurements are located in Appendix Meridian Consultants ATV Adventure Trails of the Eastern Sierra

7 Sensitive Receptors Sensitive receptors are defined as locations such as residences, hotels, motels, hospitals, schools, churches, libraries, and parks where a quiet environment is essential and people would be adversely impacted by a loud noise environment. As a whole, the proposed routes are fairly isolated and not near communities where many of these noise-sensitive receptors would occur. However, some of the combined-use routes pass through residential areas, campgrounds, and resort lodges REGULATORY SETTING Federal Regulations U.S. Environmental Protection Agency The U.S. Environmental Protection Agency (USEPA) Office of Noise Abatement and Control was originally established to coordinate federal noise control activities. After its inception, the office issued the Federal Noise Control Act of 1972, establishing programs and guidelines to identify and address the effects of noise on public health and welfare and the environment. 5 Administrators of US EPA determined in 1981 that subjective issues such as noise would be better addressed at more local levels of government. Consequently, in 1982, responsibilities for regulating noise-control policies were transferred to state and local governments. However, noise-control guidelines and regulations contained in the rulings of the US EPA in prior years remain in place by designated federal agencies where relevant. With respect to noise generated by OHVs, the Federal Noise Control Act of 1972 established guidelines for the testing and labeling of OHVs. The noise emission standards were originally intended for application to OHVs distributed and sold through commerce. This measurement procedure and labeling standard is known as USEPA F-76a and requires testing of a vehicle while accelerating past the measurement location at a perpendicular distance of 50 feet. During this test procedure, the unit under test must not exceed 80 db for engines with a displacement smaller than 170 cubic centimeters (cc) and 82 db for engines with a displacement greater than 170 cc. As described, this procedure is specifically addressed to the testing of OHVs as developed and distributed by manufacturers and retailers. As such, the criteria and procedures established in the Federal Noise Control Act of 1972 do not account for increases in OHV noise due to modifications to the vehicle by individual owners, which has become commonplace to increase the performance of OHVs. 5 Noise Control Act of 1972, sec. 2 (1972). Meridian Consultants ATV Adventure Trails of the Eastern Sierra

8 Because the test method requires a professional user and adequate space and terrain for implementation, it is not practical as a field enforcement test State Regulations Off-Highway Motor Vehicle Recreation Act of 2003 The Off-Highway Motor Vehicle Recreation Act of 2003 (California State Assembly 2002) and California Vehicle Code, Section 38370, establish standards for regulating noise levels generated from the operation of motor vehicles. The Off-Highway Motor Vehicle Recreation Act adopted the Society of Automotive Engineers (SAE) J-1287 stationary test procedure for OHVs and established the following noise-level limits: 7 On and after January 1, 2003, off-highway motor vehicles, when operating pursuant to Section 38001, shall at all times be equipped with a silencer, or other device, which limits noise emissions. (1) Noise emissions of competition off-highway vehicles manufactured on or after January 1, 1998, shall be limited to not more than 96 db, and if manufactured prior to January 1, 1998, to not more than 101 db, when measured from a distance of 20 inches using test procedures established by the Society of Automotive Engineers under Standard J-1287, as applicable. Noise emissions of all other off-highway vehicles shall be limited to not more than 96 db if manufactured on or after January 1, 1986, and not more than 101 db if manufactured prior to January 1, 1986, when measured from a distance of 20 inches using test procedures established by the Society of Automotive Engineers under Standard J-1287, as applicable. California Department of Health Services The California Department of Health Services (DHS), Office of Noise Control has studied the correlation of noise levels and their effects on various land uses. Land use and noise compatibility criteria for Inyo County have been developed from the California Office of Noise Control Land Use Compatibility Matrix for Community Noise Exposure. Maximum acceptable noise levels for various land uses are shown in Table , Acceptable Ambient Noise Exposure by Land Use in Inyo County. 6 Wyle Laboratories, California Off-Highway Vehicle Noise Study: A Report to the California Legislature As Required by Public Resources Code Section (o), WR (El Segundo, CA: Wyle Laboratories, September 2005). 7 California Vehicle Code, sec (h) (2003). Meridian Consultants ATV Adventure Trails of the Eastern Sierra

9 Table Acceptable Ambient Noise Exposure by Land Use in Inyo County Land Use Suggested Maximum (Ldn) Residential 60 Hotels, Motels 60 Schools, Libraries, Churches, Hospitals, Extended Care Facilities Auditoriums, Concert Halls, Amphitheaters Sports Arenas, Outdoor Spectator Sports Playgrounds, Neighborhood Parks 70 Golf Courses, Riding Stables, Water Recreation, Cemeteries Office Buildings, Business, Commercial and Professional Mining, Industrial, Manufacturing, Utilities, Agriculture Note: Source: Inyo County General Plan, Public Safety Element, 9-36 (2001) Local Regulations Inyo County General Plan Public Safety Element The Public Safety Element of the Inyo County General Plan identifies goals, policies, and implementation measures designed to maintain a safe environment and to protect public safety and property. 8 The applicable polices set forth to minimize noise impacts are as follows: Policy NOI-1.1 Policy NOI-1.5 Acceptable Noise Limits. The County shall utilize the noise levels based on standards shown in Table for evaluating project compatibility related to noise. Implementation of Mitigation Measures. Require that proponents of new projects provide or fund the implementation of noise-reducing mitigation measures to reduce noise to required levels. 8 Inyo County General Plan, Draft Plan, 7-18 (2013), PublicSafety.pdfhttp:// Meridian Consultants ATV Adventure Trails of the Eastern Sierra

10 Policy NOI-1.6 Policy NOI-1.8 Policy NOI-2.3 Indoor Noise Levels. In the event that acceptable outdoor noise levels cannot be achieved by appropriate noise mitigation measures, indoor noise levels for residential uses shall be designed to not exceed 45-dB Ldn. Coordination with Agencies. The County will encourage other government agencies to implement noise-reducing measures when impacts to receptors within the County s jurisdiction occur. Buffers. Provide buffers between sensitive noise receptors and highway facilities that currently carry, or have the potential to carry, high vehicle loads. City of Bishop General Plan The Noise Element in the City of Bishop General Plan is consistent with the goals and policies set forth in the Inyo County General Plan. The purpose of the Noise Element is intended to limit the exposure of residents of the City to excessive noise levels generated by various sources. 9 The following policies are applicable to the proposed Project: Encourage the development of noise standards for motor vehicles by governmental agencies, including the Highway Patrol and the Bishop Police Department. The noise impact of intermittent activities, including those at the Fairgrounds, City Park, and new construction sites, should be considered and appropriate time limits of operation should be established. The California Environmental Quality Act (CEQA) environmental review process, including potential mitigation measures, shall be utilized to identify and mitigate the potentially significant noise impacts generated by automobiles, industry, and airport operations. Inyo County Code Noise standards for roads and recreational use are identified in the Inyo County Code, Chapter 12, Section , 10 which states the following: No person shall at any time disturb the peace and quiet by any loud or unusual noise or by hooting, calling, blowing of automobile horns or other noise-making devices, or by the use of vulgar, immoral, profane or indecent language or conduct, or by boisterous or 9 City of Bishop General Plan, Noise Element, p. 10-4, (1981). 10 Inyo County Code, ch. 12, sec Meridian Consultants ATV Adventure Trails of the Eastern Sierra

11 threatening behavior. Furthermore, quiet hours at all county parks and campgrounds shall be from 10 PM to 8 AM daily, with the exception of Tecopa Hot Springs Park, which shall be 8 PM to 8 AM. Inyo County AB 628 Implementing Procedures Section 17 of the Inyo County AB 268 Implementing Procedures restricts the operation of combined-use routes by OHVs in residential areas to between dawn and dark, and no earlier than 7:00 AM or later than 8:00 PM. This rule corresponds with California Vehicle Code Section , which prohibits the operation of OHVs on the highway during the hours of darkness. Bishop Municipal Code Noise standards are identified in the Bishop Municipal Code, Chapter 8, Section , 11 which states the following: It shall be unlawful for any person to make, continue or cause to be made or continued within the limits of the city, any loud, unnecessary or unusual noise, which injures or endangers the health, peace or safety of others; provided, however that this chapter will not in any way affect, restrict or prohibit any of the activities incidental to construction or repairing being conducted after the hour of seven a.m. or before the hour of ten p.m THRESHOLDS OF SIGNIFICANCE In order to assist in determining whether a project would have a significant effect on the environment, the CEQA Guidelines identify criteria for conditions that may be deemed to constitute a substantial or potentially substantial adverse change in physical conditions. Specifically, Appendix G of the State CEQA Guidelines (Environmental Checklist Form) lists the following thresholds under which a project may be deemed to have a significant impact on noise if it would result in: 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. 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. 11 Bishop Municipal Code, ch. 8, sec Meridian Consultants ATV Adventure Trails of the Eastern Sierra

12 Potential noise impacts that were determined to be less than significant or have no impact are discussed in Section 7.1, Effects Found Not to Be Significant PROJECT IMPACTS The environmental impact analysis presented below is based on determinations made in the Initial Study (IS) for impacts considered to be potentially significant and for impacts identified by reviewing agencies, organizations, or individuals commenting on the Notice of Preparation (NOP) as potentially significant (see Responses to NOP, Appendix 2.0-d) 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 Impact Analysis The proposed Project would designate 38 combined-use routes, encompassing approximately 250 miles, that include both County- and City-maintained roads. The proposed combined-use routes would link lodging and service facilities with roadways and trails where OHVs are currently permitted on federally managed lands, or would provide links between existing OHV routes and other such currently existing roadways and trails. As the proposed Project would occur on existing roads, no construction activities would occur, and no construction-related noise would be generated. As stated in Section 3.0, Project Description, the operation of combined-use routes by OHVs in nearby residential areas would be restricted to between dawn and dark, and no earlier than 7:00 AM or later than 8:00 PM. Additionally, OHV users would be required to comply with Chapter 12, Section of the Inyo County Code which restricts OHV activity at all county parks and campgrounds from 10:00 PM to 8:00 AM daily, with the exception of Tecopa Hot Springs Park from 8:00 PM to 8:00 AM daily. According to the California State Parks Off-Highway Motor Vehicle Recreation Division (OHMVR Division), sound emissions from OHVs typically range from 96 db(a) to 101 db(a), with newer models (post 1998) ranging from 92 to 94 db(a). 12 Increased OHV use would raise ambient noise levels in the immediate project vicinity. As mentioned previously, sound generated by a point source typically diminishes or attenuates at a rate of 6 db(a) for each doubling of distance from the source to the receptor at acoustically hard sites and at a rate of 7.5 db(a) at acoustically soft sites. A hard, or 12 California State Parks Off-Highway Motor Vehicle Recreation (OHMVR) Division, OHV Sound Regulations, Meridian Consultants ATV Adventure Trails of the Eastern Sierra

13 reflective, site consists of asphalt, concrete, and very hard-packed soil, which does not provide any excess ground-effect attenuation, while an acoustically soft site consists of normal earth and most ground with vegetation. 13 The average noise level of an OHV travelling approximately 35 miles per hour (mph) with a noise level of 96 db(a) at a reference distance of 6 feet would attenuate to 65 db(a) at a distance of 100 feet. As mentioned previously, ambient noise was monitored to establish baseline ambient noise levels for the Project area. The Federal Highway Traffic Noise Prediction Model (FHWA-RD ) was used to determine ambient to proposed Project noise levels. Modeling data referenced in this analysis is provided in Appendix 5.11, Noise Calculations. Table , Project Noise Levels, shows the potential noise increases generated by the proposed Project for each of the sample locations surveyed. The Inyo County Code and Bishop Municipal Code do not establish ambient noise standards governing traffic noise for vehicles and OHVs. However, as shown in Table , the recommended maximum allowable ambient noise exposure for low-density residential and high-density residential land uses is 60 to 65 Ldn, respectively. It is important to note that noise levels on a Ldn scale represent a 24 hour average. It is important to note that noise increases from OHVs are immediate and do not reflect the average ambient noise levels (Ldn). Additionally, the proposed Project would operate for approximately hours a day and OHV travel would be short term and intermittent. As OHV travel would not occur over a 24 hour period, it is unlikely that the proposed Project would exceed the County s thresholds. 13 USDOT FHA, Fundamentals and Abatement of Highway Traffic Noise (1980), 97. Meridian Consultants ATV Adventure Trails of the Eastern Sierra

14 Measurement Location Min Max Table Project Noise Levels Baseline Ambient Noise Level (db(a)) Nearest Sensitive Receptor Location ft Location ft Location ft Location ft Location ft Location ft Location ft Location ft Location ft Location ft Location ft Location ft Location ft Location ft Average Noise Level with Project (db(a)) Note: Noise monitoring was conducted over 15-minute intervals on March 13, 2014 between 6:45 AM and 1:00 PM. Noise measurements are located in Appendix As shown in Table , several locations have experienced singular noise spikes as high as 84 db(a). Sources of these noise spikes are from large trucks, speeding automobiles, and motorcycles. With these short-term noise spikes, locations retained an ambient noise level of db(a). Implementation of the proposed Project would realistically increase noise levels by 3 to 7 db(a). Due to the location of the proposed combined-use routes throughout the area, it is difficult to predict the concentration of OHV activity along any of the specific routes. Depending on the season, weather, and popularity amongst OHV users, certain routes may experience more use than others. As discussed in Section 5.15, Transportation and Traffic, the proposed Project would contribute an additional 1,406 average daily trips over the six areas during peak seasons (March 21 through June 21, and September 1 through October 31), and an additional 805 average daily trips over the six areas during off-peak seasons (June 22 through August 31, and November 1 through March 20). This corresponds to an average increase in OHV use throughout the proposed network of combined-use routes of approximately 2.7 percent during peak season, and 1.35 percent during the off-peak season. This increase in traffic is Meridian Consultants ATV Adventure Trails of the Eastern Sierra

15 considered minor; moreover, because of the large area of the proposed combined-use routes, constant accumulation of OHV travel along a concentrated portion of the Project site is unlikely. Additionally, studies have shown that the installation of quieter aftermarket exhaust systems have the potential reduce noise emissions from 2 to 9 db(a). 14 Currently, the mandatory installations of aftermarket exhaust systems for OHVs are not enforced. However, the Applicant would conduct public outreach and education programs encouraging the use of aftermarket exhaust systems to improve noise emissions for OHVs. Additionally, studies have shown that a reduction in speed would reduce the revolutions per minute (RPM) for OHVs, which would in turn reduce the noise generated from engines. 15 Human response to sound is highly individualized. Annoyance occurs with abrupt noise levels. Many factors influence the response to noise, including the character of the noise, the variability of the sound level, the presence of tones or impulses, and the time of day of the occurrence. Thus, the reaction to noise is highly subjective, with the perceived effect of a particular noise varying widely among individuals in a community. The effects of noise could result in subjective effects of annoyance, nuisance, and dissatisfaction. The Inyo County Code and Bishop Municipal Code do not establish ambient noise standards governing traffic noise for vehicles and OHVs. While there would be a minor traffic increase, the operation of combined-use routes by OHVs in nearby residential areas (including those in Bishop and along Birch Creek Road, as well as those in Big Pine, Aberdeen, Independence, and Lone Pine) would be restricted to between dawn and dusk and no earlier than 7:00 AM or later than 8:00 PM. While the provisions allow for a 12- to 13-hour period for OHV travel, peak concentrations of OHV travel would likely occur during the hours of 10:00 AM to 4:00 PM, which are typically the peak hours for leisure activities. While OHV trails would be accessible during all days of the week, peak activities would likely occur during weekends or holidays. Based on these factors, OHV-generated noise is unlikely to generate nuisances that would prohibit nearby residents from sleeping or enjoying quiet times in their homes. As mentioned in Section 5.2, Agriculture and Forest Resources, OHVs passing closely near grazing lands could create noise that could startle grazing animals and other wildlife. However, the use of signage associated with the proposed Project would reduce adverse impacts to agricultural and forest resources to a less-than-significant level. 14 Wyle Laboratories, California Off-Highway Vehicle Noise Study (September 2005). 15 Wyle Laboratories, California Off-Highway Vehicle Noise Study (September 2005). Meridian Consultants ATV Adventure Trails of the Eastern Sierra

16 As described in Section 5.4, Biological Resources, wildlife exposed to noise can suffer high levels of physiological stress. Noise can also cause a species to be displaced into a marginal or unsuitable habitat, which can have lasting effects on survival and productivity. For some species, the noise of OHVs can directly interfere with critical behaviors such as foraging or breeding, and OHV noise may simulate that of natural sounds for example, thunder to which many animals may be adapted to respond. 16 Additionally, hearing loss can occur in some species when exposed to prolonged OHV noise. However, the use of signage associated with the proposed Project would reduce adverse impacts to biological resources to a less-than-significant level. As previously stated, the proposed Project would contribute an additional 1,406 average daily trips over the six areas during peak seasons (March 21 through June 21, and September 1 through October 31), and an additional 805 average daily trips over the six areas during off-peak seasons (June 22 through August 31, and November 1 through March 20). This corresponds to an average increase in OHV use throughout the proposed network of combined-use routes of approximately 2.7 percent during peak season, and 1.35 percent during the off-peak season. While the increase is minor, the behavioral pattern of OHV users are unpredictable and an unexpected high concentration of OHVs could occur along certain popular roads. Therefore, the potential for noise impacts would still exist. Impacts would be potentially significant. Mitigation Measures The following mitigation measures are identified to reduce significant noise impacts: MM-NOI-1 MM-NOI-2: Where combined-use routes are located less than 100 feet from sensitive receptors, the Signage Plan shall be modified to include signage to reduce OHV speeds to 25 mph. Modifications to the Signage Plan shall be consulted and designed in accordance with Caltrans specifications. The Project Applicant shall conduct ongoing community and public outreach programs to work with local OHV groups and OHV-related businesses. The outreach program should include awareness with respect to aftermarket exhaust systems (e.g., mufflers), reducing noise emissions, and the importance of staying on designated combined-use routes. 16 Douglas S. Ouren et al., Environmental Effects of Off-Highway Vehicles on Bureau of Land Management [BLM] Lands, US Geological Survey Open-File Report (Reston, VA: US Department of the Interior and US Geological Survey, 2007). Meridian Consultants ATV Adventure Trails of the Eastern Sierra

17 Community and/or public outreach should be conducted in the form of an educational program, including the use of informational brochures and pamphlets, posting brochures on existing kiosks, and providing OHV vendors (such as rental companies) with brochures to be distributed to OHV users during safety orientations as part of OHV rental registration. MM-NOI-3: Upon implementation of the proposed Project, the County of Inyo or the City of Bishop shall implement a noise-monitoring program for routes located within their respective jurisdictions within 100 feet from sensitive receptors to determine if increased noise from OHV use exceeds acceptable standards over a 24hour period (60 65 Ldn). If noise levels are exceeded, then the County or City, depending on jurisdiction, shall close the combined-use routes to travel by OHVs. Level of Significance after Mitigation Impacts would be less than significant A substantial permanent increase in ambient noise levels in the project vicinity above levels existing without the project Impact Analysis The proposed Project would not create any stationary noise sources because it does not involve the construction of any facility, residential buildings or roads. All noise attributed to the proposed Project would come from mobile sources. As previously stated, the proposed Project would contribute an additional 1,406 average daily trips over the six areas during peak seasons (March 21 through June 21, and September 1 through October 31), and an additional 805 average daily trips over the six areas during off-peak seasons (June 22 through August 31, and November 1 through March 20). This corresponds to an average increase in OHV use throughout the proposed network of combined-use routes of approximately 2.7 percent during peak season, and 1.35 percent during the off-peak season. The increase in trips would increase the ambient noise levels above levels existing without the Project. OHV activity would occur only along Countydesignated routes, and it would be dispersed throughout the day during operational hours, between 8:00 AM and 8:00 PM. While the provisions allow for a 12-hour period for OHV travel, peak concentrations of OHV travel would likely occur during the hours of 10:00 AM to 3:00 PM, as it is typically the peak hours for leisure activities. Meridian Consultants ATV Adventure Trails of the Eastern Sierra

18 Additionally, it is unlikely that an increase in noise levels would occur on a daily basis. It is anticipated that the 2.7 percent traffic increase would occur during peak seasons and 1.35 percent during off-peak seasons. As shown on Table , Project Noise Levels, sensitive receptors that are less than 100 feet from a combined-use route are likely to experience increased noise spikes over db(a). However, OHV travel would be sporadic and unpredictable, and limited to daytime hours. Popularity of OHV routes are often determined by general weather conditions and consensus amongst OHV users. Because of this irregularity, an overall daily average above 65 Ldn is highly unlikely. As stated previously, during the peak seasons (spring and fall), the proposed Project would generate an overall increase of approximately 2.7 percent. While the increase is minor, the behavioral pattern of OHV users are unpredictable, and the potential for noise levels occurring above ambient levels would still exist. Impacts would be potentially significant. Mitigation Measures Mitigation measure MM-NOI-1, MM-NOI-2, and MM-NOI-3 have been identified to reduce impacts. Level of Significance after Mitigation Impacts would be less than significant A substantial temporary or periodic increase in ambient noise levels in the project vicinity above levels existing without the project Impact Analysis The proposed Project involves the designation of existing roadways as combined-use routes to connect existing OHV trail segments and recreation areas with goods and services. No construction, demolition, or earthmoving activities would occur. Prior to the Project s implementation, County, State Department of Parks and Recreation, and Caltrans staff would travel along designated sites to install appropriate signage for the proposed Project. However, noise generated from these mobile sources would be considered minimal and less than significant. Mitigation Measures No mitigation is required. Level of Significance after Mitigation Impacts would be less than significant. Meridian Consultants ATV Adventure Trails of the Eastern Sierra

19 INDIRECT IMPACTS Impact Analysis The operation of combined-use routes by OHVs in nearby residential areas would be restricted to between dawn and dark, and no earlier than 7:00 AM or later than 8:00 PM. While the provisions allow for a 12- to 13-hour period for OHV travel, peak concentrations of OHV travel would likely occur during the hours of 10:00 AM to 4:00 PM, typical peak hours for leisure activities. Peak activities would likely occur during weekends or holidays. Under the proposed Project, OHV users would be limited to those combined-use routes designated as part of the program and subject to the operating restrictions (hours of use) and noise curfew specified by the appropriate jurisdictions, thereby minimizing OHVs effects on sensitive receptors. OHV could continue in areas that the combined use routes link to and would be subject to the restrictions and conditions of use as determined by the landowners or agencies responsible for those areas. Indirect impacts from increased noise would be less than significant. As stated in Section 5.4, Biological Resources, wildlife behaviors, particularly foraging, hunting, and savaging, typically occur during dusk or dawn. Other behaviors, such as breeding, are typically seasonal. As OHV use tends to increase in the late morning and peak in the early afternoon, and then decrease in the late afternoon and early evening hours, potential impacts to wildlife would be minimized on Countymaintained and surrounding lands. Should OHV riders venture into OHV routes located in surrounding lands, OHV users would be subject to applicable curfew and noise ordinances. Indirect noise impacts on wildlife would be less than significant. As stated in Section 5.2, Agriculture, increase in OHV activity may potentially affect grazing activities to surrounding lands as a result in increases in noise and potential OHV use of non-designated routes, and could result in adverse effects on livestock in the area. The average noise level of an OHV travelling approximately 35 miles per hour (mph) could exceed local noise thresholds when OHV vehicles pass through grazing areas. Noise impacts would be short-term occurring only when the OHVs pass through an area but could be as loud as 65.5 db(a) at a distance of 100 feet along the designated routes (based on a noise level of 96 db(a) from the OHV source). This noise level would be considered minor as it would be short-term, and would result in less than significant impacts to grazing animals. The California Vehicle Code sets a prima facie speed limit of 15 mph for vehicles within 50 feet of people or animals, which would apply to OHVs passing active grazing areas. This speed limit would reduce the revolutions Meridian Consultants ATV Adventure Trails of the Eastern Sierra

20 per minute (RPM) for OHVs, which in turn would reduce the noise generated from engines. 17 Further, the use of a signage associated with the proposed Project would alert OHV users of the proximity of livestock in grazing areas, and assist in reducing indirect noise impacts to less than significant levels. Mitigation Measures No mitigation is required. Level of Significance after Mitigation Impacts would be less than significant CUMULATIVE IMPACTS Impact Analysis As noted in Section 4.0, Environmental Setting, the related projects are a combination of potential, proposed, and future projects, along with applicable planning documents. As shown in Table 4.0-8, Related Projects, related projects would not directly result in the development of residential units. When combined with the proposed Project, related projects would result in 80,000 square feet of hotel and casino space, 578,194,758 square feet of industrial space (primarily solar facilities), and 2,382,732 square feet of ranch space. Local federal and County plans have been incorporated into the list to create a programmatic evaluation of cumulative impacts. OHV hours of operation and speed limits would be restricted by the California Vehicle Code, which would reduce noise impacts to less than significant levels. Noise impacts are localized in nature and decrease with distance. Consequently, to achieve a cumulative increase in noise, more than one source emitting high levels of noise would need to be in close proximity to the noise receptor. As mentioned, the proposed Project would not result in any stationary sources of noise. It is assumed that all related projects with stationary noise sources would adhere to County noise standards and provide adequate noise shielding or abatement measures so as not to cause a substantial increase in ambient noise levels. The proposed Project would generate mobile sources of noise; however, this increase would only occur during daytime hours and during peak seasons or the weekend. The mobile sources of noise are 17 Wyle Laboratories, California Off-Highway Vehicle Noise Study (September 2005). Meridian Consultants ATV Adventure Trails of the Eastern Sierra

21 temporary by nature because they are primarily tourism driven, and they would not contribute to an overall permanent increase in ambient noise. The Project s contribution would not be considered considerable, and cumulative impacts would be less than significant. Mitigation Measures No mitigation is required. Level of Significance after Mitigation Cumulative impacts would be less than significant. Meridian Consultants ATV Adventure Trails of the Eastern Sierra

22 EXAMPLES DECIBELS (db) SUBJECTIVE EVALUATIONS NEAR JET ENGINE 140 THRESHOLD OF PAIN 130 DEAFENING THRESHOLD OF FEELING HARD ROCK BAND 120 ACCELERATING MOTORCYCLE AT A FEW FEET AWAY* 110 LOUD AUTO HORN AT 10' AWAY NOISY URBAN STREET NOISY FACTORY SCHOOL CAFETERIA WITH UNTREATED SURFACES continuous exposure above here is likely to degrade the hearing of most people VERY LOUD STENOGRAPHIC ROOM NEAR FREEWAY AUTO TRAFFIC AVERAGE OFFICE Range of Speech LOUD MODERATE SOFT RADIO MUSIC IN APARTMENT 40 AVERAGE RESIDENCE WITHOUT STEREO PLAYING 30 FAINT AVERAGE WHISPER 20 RUSTLE OF LEAVES IN WIND HUMAN BREATHING 10 VERY FAINT THRESHOLD OF AUDIBILITY 0 * NOTE: 50' from motorcycle equals noise at about 2000' from a four-engine jet aircraft. NOTE: db are average values as measured on the A scale of a sound level meter. FIGURE Common Noise Levels

23 Routes #12 End point Routes #8 & #14 End point 14 Silver Canyon Rd Route #16 End point Silver Canyon Rd Silver Canyon Rd Route #6 End point Route #7 End point 11 Schober Ln Route #10 End point 10 Routes #1, #2, #3, #4, #5, #15 End point BLACK CYN RD Route #9 End point BLACK CYN RD Route #18 End point LEGEND Noise Monitor Project Routes Federal OHV Trail Segments SOURCE: Inyo County Planning Department ; (For illustrative purposes only.) N FIGURE Noise Measurement Locations for Bishop Site

24 TINNEMAHA RD BIRCH CREEK RD 6 Route #3 End point TINNEMAHA RD Route #2 End point TABOOSE CREEK RD Routes #1, #2, #3 Start point Aberdeen 5 LEGEND Noise Monitor Route #1 End point Project Routes Federal OHV Trail Segments DIVISION CREEK RD DIVISION CREEK RD N SOURCE: Inyo County Planning Department ; (For illustrative purposes only.) FIGURE Noise Measurement Locations for Aberdeen Site

25 9 8 7 LEGEND Routes #2 & #3 End point Noise Monitor Project Routes Federal OHV Trail Segments SOURCE: Inyo County Planning Department ; (For illustrative purposes only.) N FIGURE Noise Measurement Locations for Big Pine Site