Level of Significance after Mitigation Impacts would be less than significant.

Transcription

1 Level of Significance after Mitigation Impacts would be less than significant. 4.8 NOISE This section assesses noise impacts associated with the proposed project. It analyzes both potential noise impacts caused by the construction and operation of the church. Mitigation measures are proposed for any impacts determined to be significant. Background on Noise Sound is mechanical energy transmitted by pressure waves in a compressible medium such as air. Noise can be defined as unwanted sound. Sound is characterized by various parameters that include the rate of oscillation of sound waves (frequency), the speed of propagation, and the pressure level or energy content (amplitude). In particular, the sound pressure level has become the most common descriptor used to characterize the loudness of an ambient sound level. Noise levels are measured on a logarithmic scale in decibels (db) that represent the fluctuation of air pressure above and below atmospheric pressure. Because this is a logarithmic scale, a doubling of sound energy results in a 3 db increase in noise levels. A noise level change of less than 3 db is considered imperceptible to the human ear. Since the human ear is not equally sensitive to all frequencies within the entire spectrum, noise measurements are weighted more heavily within those frequencies of maximum human sensitivity in a process called Aweighting, written as dba. Noise levels are generally higher during the daytime and early evening when traffic, commercial, and industrial activity is the greatest. Noise sources experienced during night-time hours, however, when background levels are generally lower can be potentially more conspicuous and irritating to the receiver. In order to evaluate noise in a way that considers periodic fluctuations experienced throughout the day and night, noise measurements are weighted and added over a 24-hour period to reflect magnitude, duration, frequency, and time of occurrence. New Paradise Church Draft EIR 72 August 2007

2 A number of different types of metrics are used to characterize the time-varying nature of sound. These metrics include: the equivalent continuous sound level (L eq ), the minimum and maximum sound levels (L min and L max ), percentile-exceeded sound levels (L xx ), the day-night level, and the community noise equivalent level (CNEL). The following are brief definitions of these metrics and other terminologies used in this section: Sound A vibratory disturbance created by a vibrating object, which, when transmitted by pressure waves through a medium such as air, is capable of being detected by a receiving mechanism, such as the human ear or a microphone. Noise Sound that is loud, unpleasant, unexpected, or otherwise undesirable. Decibel (db) A unit-less measure of sound on a logarithmic scale, which indicates the squared ratio of sound pressure amplitude to reference sound pressure amplitude. The reference pressure is 20 micro-pascals. Weighted Decibel (dba) An overall frequency-weighted sound level in decibels that approximates the frequency response of the human ear. Maximum Sound Level (L max ) The maximum sound level measured during the measurement period of interest. Minimum Sound Level (L min ) The minimum sound level measured during the measurement period of interest. Equivalent Sound Level (L eq ) The equivalent steady state sound level, which in a stated period of time would contain the same acoustical energy. Percentile-Exceeded Sound Level (L xx ) The sound level exceeded x percent of a specific time period. L 10 is the sound level exceeded 10 percent of the time. Day-Night Level (L dn ) The energy average of the A-weighted sound levels occurring during a 24-hour period, with 10 db added to the A-weighted sound levels occurring during the period from 10: 00 p. m. to 7: 00 a. m. Community Noise Equivalent Level (CNEL) The energy average of the A-weighted sound levels occurring during a 24-hour period with 5 db added to the A-weighted sound levels occurring during the period from 7:00 p.m. to 10:00 p.m. and 10 db added to the A-weighted sound levels occurring during the period from 10:00 p.m. to 7:00 a.m.. New Paradise Church Draft EIR 73 August 2007

3 Construction Noise Construction of facilities and structures involves the use of equipment. This generates high noise levels and adversely affects noise sensitive uses. The following are considered when assessing the impact of construction noise upon the environment: (1) the nature and level of activities that generate the noise, (2) the pathway through which the noise travels, (3) the sensitivity of the receptor, and (4) the period of exposure. Typical construction equipment types are presented in Table 2. Noise levels from these construction equipment types ranges from 76 to 91 dba for equipment powered by internal combustion engines, saws, and vibrators. Noise levels for impact equipment are from the mid- 80s to more than 100 dba. Table 3 provides typical noise levels for each construction phase. The excavation and finishing phases have the noisiest level among the construction activities. Construction noise can be created from both on-site and off-site sources. On-site noise during construction would occur primarily from heavy-duty diesel-powered construction equipment during activities such as ditching, grading, backfilling, etc. Offsite noise sources would occur from trucks delivering materials and equipment to and from the job-site, as well as from vehicles used by workers commuting to and from the proposed job site. Operational Noise Due to the size of the proposed church, the stationary and mobile vehicular noise sources associated with the operation of the proposed church would not significantly increase the existing noise levels of the current environmental setting. Similar to construction noise, long-term operational noise can be created from both on-site and off-site sources. On-site noise during operations would occur primarily from operations of mechanical equipment (e.g., air conditioning), other sources such as periodic landscape maintenance, and activities from the proposed project (e.g. singing hymns, handclapping). Offsite noise sources would occur from increased vehicle trips to the site. Table 3: Noise Level Ranges of Typical Construction Equipment New Paradise Church Draft EIR 74 August 2007

4 Equipment Levels in dba at 50 Feet* Front Loader Trucks Cranes (moveable) Cranes (derrick) Vibrator Saws Pneumatic Impact Equipment Jackhammers Pumps Generators Compressors Concrete Mixers Concrete Pumps Back Hoe Pile Driving (peaks) Tractor Scraper / Grader Paver * Machinery equipped with noise control devices or other noise-reducing design features does not generate the same level of emissions as that shown in this table. Source: EPA, Noise from Construction Equipment and Operations, Building Equipment and Home Appliances, PB , Table 4: Outdoor Construction Noise Levels Construction Phase Noise Level (dba L eq ) Noise Levels at 50 feet with 50 Feet Mufflers (dba) Ground Clearing New Paradise Church Draft EIR 75 August 2007

5 Excavation, Grading Foundations Structural Finishing Source: EPA, Noise from Construction Equipment and Operations, Building Equipment and Home Appliances, PB , Environmental Setting The project parcel and nearby vicinity are primarily exposed to noise generated by traffic from the surrounding streets, operational noises from nearby schools, and residential noise sources (e.g., passenger vehicles and landscape maintenance operations). Sensitive receptors within the proposed project vicinity include schools and a mix of residential units located adjacent to the project parcel. Office buildings in the vicinity of the project parcel are not considered noise sensitive uses. Environmental Impacts Thresholds of Significance According to the City of Los Angeles L.A. CEQA Thresholds Guide (2006), a project would normally have a significant impact on noise levels from construction if: Construction activities lasting more than one day would exceed existing ambient exterior noise levels by 10 dba or more at a noise sensitive use; Construction activities lasting more than 10 days in a three month period would exceed existing ambient exterior noise levels by 5 dba or more at a noise sensitive use; or Construction activities would exceed the ambient noise level by 5 dba at a noise sensitive use between the hours of 9:00 p.m. and 7:00 a.m. Monday through Friday, before 8:00 a.m. or after 6:00 p.m. on Saturday, or at anytime on Sunday. According to the City of Los Angeles L.A. CEQA Thresholds Guide (2006), a project would normally have a significant impact on noise levels from project operations if the project causes the ambient noise level measured at the property line of affected uses to increase by 3 dba in New Paradise Church Draft EIR 76 August 2007

6 CNEL to or within the normally unacceptable or clearly unacceptable category, or any dba or greater noise increase (see Table 4 below). Table 5: Community Noise Exposure Community Noise Exposure, CNEL, db Land Use Normally Acceptable Conditionally Acceptable Normally Unacceptable Clearly Unacceptable Single Family, Duplex, Above 70 Mobile Homes Multi-Family Homes Above 70 Schools, Libraries, Above 80 Churches, Hospitals, Nursing Homes Transient Lodging Motels, Above 80 Hotels Auditoriums, Concert Halls, Above 65 Amphitheaters Sports Arena, Outdoor Above 70 Spectator Sports Playgrounds, Neighborhood Above 72 Parks Golf Courses, Riding Above 80 Stables, Water Recreation, Cemeteries Office Buildings, Business Above and Professional Commercial Industrial, Manufacturing, Utilities, Agriculture Above Normally Acceptable: Specified land use is satisfactory, based upon the assumption that any buildings involved are of normal conventional construction without any special noise insulation requirements. Conditionally Acceptable: New construction or development should be undertaken only after a detailed analysis of the noise reduction requirements is made and needed noise insulation features included in the design. Conventional construction, but with closed windows and fresh air supply systems or air conditioning will normally suffice. Normally Unacceptable: New construction or development should generally be discouraged. If new construction or development does proceed, a detailed analysis of the noise reduction requirements must be made and needed noise insulation features included in the design. Clearly Unacceptable: New construction or development should generally not be undertaken. Source: California Department of Health Services (DHS) New Paradise Church Draft EIR 77 August 2007

7 Presumed Ambient Noise Levels, as set forth in the Los Angeles Municipal Code (LAMC), Section (Table 5) will be used as the methodology to determine the significant for noise. Table 6: Presumed Ambient Noise Levels (dba) ZONE DAY NIGHT Residential A1, A2, RA, RE, RS, RD, RW1, RW2, R1, R2, R3, R4, R5 Commercial P, PB, CR, C1, C1.5, C2, C4, C5, CM Manufacturing M1, MR1, MR Heavy Manufacturing M2, M Source: LAMC, Section Impact & Mitigation #15 Impact: Construction activities would result in substantial, temporary increases in existing ambient noise levels within the project vicinity. Construction activities including clearing, grading, hauling, framing, and completion of the building construction on-site would create short-term noise increases perceived by sensitive noise receptors located within 1,000 feet of the project parcel. Noise sensitive receptors such as schools and local residents surrounding the project parcel would potentially perceive short-term noise increases when: (1) construction vehicles would enter and leave the site (with workers, building materials, or construction equipment); (2) activities would occur in construction staging areas; (3) during operation of temporary onsite generators; (4) grading activities occur; and (5) during building construction. The intensity of potential noise impacts would depend upon (1) the proximity of the noise receivers to the area under construction, (2) the number and type of construction equipment operating each day, and (3) the length of time each piece of equipment would be in use. Impacts due to construction on noise would be temporary. New Paradise Church Draft EIR 78 August 2007

8 Based on criteria established in the Draft L.A. CEQA Threshold Guide, construction activities lasting more than one day, which would increase ambient exterior noise levels by 10 dba or more at a noise sensitive use, may result in a significant impact. The construction activities associated with the proposed project would result in an increase in ambient exterior noise levels at noise sensitive use of the adjacent residential housing and the middle school by more than 10 dba. However, the increase in noise levels at these offsite locations would be temporary in nature, and would not generate continuously high noise levels. Some of the typical noise generating construction activities would also be eliminated from this project given the reliance on prefabricated materials and scale of the project. Furthermore, construction activities associated with the proposed project would be required to comply with the noise regulations found in Section of the LAMC which prohibits noise generating activities between 9:00 P.M. and 7:00 A.M. on weekdays and 6:00 P.M. and 8:00 A.M. on Saturdays. Additionally, Implementation of Mitigation Measures N#1 through N#9 would also reduce the impacts. However, due to the proximity to noise sensitive land uses, the temporary construction noise impacts are expected to be temporary and unavoidable. Mitigation Measures: {N#1} Construction activity for site preparation and for future development shall be limited to the hours of 7:00 a.m. to 6:00 p.m., Monday through Friday, and 8:00 a.m. to 6:00 p.m. on Saturday. No construction shall occur on State Holidays (e.g., Thanksgiving, Labor Day). Construction equipment maintenance shall be limited to the same hours. Non-noise generating construction activities (e.g., painting, landscaping with hand tools, etc.) should not be subject to these restrictions. {N#2} Stationary construction equipment that generates noise that exceeds 65dBA at the project boundaries shall be shielded with the modern and effective noise control devices (i.e., mufflers, lagging, and/or motor enclosures). All equipment shall be properly maintained to ensure that no additional noise, due to worn or improperly maintained parts, would be generated. New Paradise Church Draft EIR 79 August 2007

9 {N#3} The project applicants shall notify the sensitive noise receptors 72 hours in advance of any and all construction activities. The construction manager s (or representative s) telephone number shall also be provided with the notification so that community concerns can be communicated. {N#4} Contractors will monitor construction noise levels to ensure compliance with the noise ordinance. In the event of complaints by nearby residents or receptors, the contractors will monitor noise from the construction activity to ensure that construction noise does not exceed limits specified in the City of Los Angeles Noise Ordinance No and and any subsequent ordinances, which prohibit the emission or creation of noise beyond certain levels at adjacent uses unless technically infeasible. In the event that construction noise exceeds the specified limits, appropriate measures will be implemented to limit noise to acceptable levels. {N#5} Construction and demolition activities shall be scheduled so as to avoid operating several pieces of equipment simultaneously, which causes high noise levels. {N#6} The construction contractor shall install noise curtains along the construction perimeter adjoining noise sensitive land uses, if found to be necessary. Fences shall be constructed around the site to minimize trespassing vandalism, short-cut attractions and attractive nuisances. {N#7} Noise and ground-borne vibration construction activities where specific location on the project site may be flexible shall be conducted as far as possible from the nearest noise and vibration sensitive land use. Due to noise impacts on the schools, no construction vehicles or haul trucks shall be staged or idled on these streets during school hours. New Paradise Church Draft EIR 80 August 2007

10 {N#8} With regard to worker exposure to high noise levels, all project personnel who could potentially be exposed to sound levels in excess of 85 dba will be provided personal protective equipment in accord with Occupational Safety and Health Administration (OSHA) regulations and guidelines. Therefore, noise impacts on project personnel would be less than significant. {N#9} The project contractor shall use power construction equipment with state-of-theart noise shielding and muffling devices. Level of Significance after Mitigation Project construction noise impacts would be temporary, yet potentially significant and unavoidable. Impact & Mitigation #16 Impact: Noise could be generated from the operation of the church, e.g. from singing hymns and clapping hands. Mitigation Measures: {N#10} Project sponsor must comply with Title 24 of the California Code of Regulations which ensures an acceptable interior noise environment. {N#11} To avoid disruption of the peace and harmony of neighbors with abutting property to the proposed site, the Church will sound proof its sanctuary in an affordable, efficient manner. {N#12} An 8-foot in height solid decorative masonry block wall shall be constructed along the south side and rear property lines (except within the front yard). {N#13} A 10-foot in height solid decorative masonry block wall shall be constructed along the north side of the property line and adjacent to that wall. New Paradise Church Draft EIR 81 August 2007

11 {N#14} A minimum five-foot wide landscape buffer shall be planted adjacent to the residential uses. Level of Significance after Mitigation Project impacts on noise would be less than significant. 4.9 PUBLIC SERVICES Environmental Impacts Thresholds of Significance The following criteria are obtained from the City of Los Angeles s Initial Study checklist. Would the project result in substantial adverse physical impacts associated with the provision of new or physical impacts associated with the provision of new or physically altered governmental facilities, construction of which would cause significant environmental impacts, in order to maintain acceptable service ratios, response times or other performance objectives for any of the public services: - Fire protection - Police protection - Schools - Parks - Other governmental services (including road)? Impact & Mitigation #17 Impact: Environmental impacts may result from project implementation due to the close proximity of the project to the school. The potential impacts will be mitigated to a level of insignificance by the following measures: Mitigated Measures: {PS#1} The developer and contractors must maintain ongoing contact with administrator of the local school. The administrative offices should be contacted when demolition, grading and construction activity begin on the project site so that New Paradise Church Draft EIR 82 August 2007