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HomeMy WebLinkAboutEx 06_Noise Study.pdf (206) 378-0569 www.greenbusch.com 1900 W Nickerson St., #201, Seattle, WA 98119  2262 N Albina Ave., #340 Portland, OR 97227 Memorandum DATE: December 8, 2022 TO: Julei Campos – Lynx Consulting, Inc. FROM: Justin Morgan, INCE RE: Comcast Kent Noise Study INTRODUCTION The intent of this Noise Study is to evaluate sound levels associated with the new equipment planned for installation at the Comcast Kent site (Site) located at 18809 116 th Avenue Southeast in Renton, Washington. This Noise Study includes a summary of applicable noise regulations, predicted sound levels at nearby properties, and recommended noise mitigation to achieve compliance with codified sound limits. SUMMARY To reduce sound emissions from the new equipment proposed at the Site, solid barriers should replace the existing chain-link fence around the perimeter of the Site. These barriers should range in height between 6-feet tall and 9-feet tall. Additionally, the proposed AirSys units should operate in “quiet mode.” Predicted sound levels with the inclusion of these barriers and AirSys units operating in “quiet mode” comply with the Renton Municipal Code sound limits at all nearby properties. ZONING AND REGULATORY CRITERIA Sound levels within the City of Renton are regulated by the Renton Municipal Code (RMC) Chapter 8.7. RMC Chapter 8-7-2 adopts by reference the maximum environmental noise levels defined in the Washington Administrative Code (WAC) Chapter 173-60. The WAC 173-60 sound limits are based on the Environmental Designation for Noise Abatement (EDNA) classification of the property containing the sound source and the EDNA classifications of properties receiving the sound. RMC Chapter 8-7-4 adopts the EDNA classifications defined in WAC 173-60-030. WAC 173-60-030 defines EDNA classifications by land use and are as follows:  Class A EDNA - Lands where human beings reside and sleep. Typically, Class A EDNA will be the following types of property used for human habitation : December 8, 2022 Page 2 Comcast Kent Noise Study (206) 378-0569 www.greenbusch.com 1900 W Nickerson St., #201, Seattle, WA 98119  2262 N Albina Ave., #340 Portland, OR 97227 o Residential o Multiple family living accommodations o Recreational and entertainment, (e.g., camps, parks, camping facilities, and resorts) o Community service, (e.g., group homes, assisted living facilities, hospitals, health and correctional facilities)  Class B EDNA - Lands involving uses requiring protection against noise interference with speech. Typically, Class B EDNA will be the following types of property: o Commercial living accommodations o Commercial dining establishments o Motor vehicle services o Retail services o Banks and office buildings o Miscellaneous commercial services, property not used for human habitation o Recreation and entertainment, property not used for human habitation (e.g., theaters, stadiums, fairgrounds, and amusement parks) o Community services, property not used for human habitation (e.g., educational, religious, governmental, cultural and recreational facilities)  Class C EDNA - Lands involving economic activities of such a nature that higher noise levels than experienced in other areas is normally to be anticipated. Persons working in these areas are normally covered by noise control regulations of the department of labor and industries. Uses typical of Class A EDNA are generally not permitted within such areas. Typically, Class C EDNA will be the following types of property: o Storage, warehouse, and distribution facilities o Industrial property used for the production and fabrication of durable and nondurable goods o Agricultural and silvicultural property used for the production of crops, wood products, or livestock In addition to land use, EDNA classifications also take into consideration the present, future, and historical use of properties, as well as the use of other lands in the vicinity. Maximum permissible sound levels are identified in WAC Chapter 173-60-040 and are shown in Table 1. Table 1. Maximum Permissible Sound Levels, dBA EDNA of Sound Source EDNA of Receiving Property Class A Class B Class C Class A 55 57 60 Class B 57 60 65 Class C 60 65 70 Source: WAC Chapter 173-60-040 December 8, 2022 Page 3 Comcast Kent Noise Study (206) 378-0569 www.greenbusch.com 1900 W Nickerson St., #201, Seattle, WA 98119  2262 N Albina Ave., #340 Portland, OR 97227 WAC Chapter 173-60-040(2)(b) includes modifications to the sound limits shown in Table 1. These modifications include a 10 dB reduction to sound levels received by Class A EDNA properties between the hours of 10:00 PM and 7:00 AM. Sounds that are exempt from the sound limits shown in Table 1 are listed in WAC 173- 60-050. WAC 173-60-050(4)(f) provides an exemption for sounds created by emergency equipment and work necessary in the interests of law enforcement or for health, safety, or welfare of the community. Because the proposed generator is an emergency generator this exemption likely applies and sounds created by the emergency generator would be exempt during testing, exercising, and operation during an emergency; however, this should be confirmed with the City of Renton. The Site is located on a currently undeveloped parcel. The Site and the parcel west of the Site are considered Class C EDNA. The property north of the Site is a school and is considered a Class B EDNA. Class A EDNA properties are located directly south of the Site and to the east, across 116th Avenue Southeast. However, the parcel the Site is located on is being subdivided and developed into single-family homes. Although the Site remains a Class C EDNA, the single-family homes being developed around the Site will be Class A EDNA. The location of the Site and future EDNA classifications are illustrated in Figure 1, and the resulting sound limits for the Site are shown in Table 2. Figure 1. EDNA Classifications December 8, 2022 Page 4 Comcast Kent Noise Study (206) 378-0569 www.greenbusch.com 1900 W Nickerson St., #201, Seattle, WA 98119  2262 N Albina Ave., #340 Portland, OR 97227 Table 2. Project Sound Limits, dBA Receiving Property EDNA of Receiving Property Project Sound Limits (day/night) North Class B 65/65 South Class A 60/50 East West ACOUSTICAL MODEL The primary tool used to predict sound levels at neighboring property lines was the 3-D computer noise modeling software environment, Cadna/A. Cadna/A utilizes the CADNA (Control of Accuracy and Debugging for Numerical Applications) computation engine developed by the Pierre et Marie Curie University of Paris. The model used for this project utilized the International Organization for Standardization 9613 Part II algorithms, implemented in the Cadna/A software, which accounted for the effects of distance, topography, and surface reflections on sound levels. The acoustical model is typically accurate to within 3 dB. Some conservative assumptions were used in the model created for this project to ensure sufficient design margin within the predicted sound levels. Therefore, predicted sound levels can be compared to applicable criteria directly, without consideration of additional design margin. The locations of the equipment were determined from drawings provided by Lynx Consulting, Inc. Topographical information and property line locations were determined from King County Geographical Information System data. Building locations and heights were estimated using Google Earth imagery. ANALYSIS The new Comcast equipment cabinet, the two Comcast battery cabinets, the 100-kilowatt (kW) emergency generator, and the existing equipment shelter were placed in the computer noise model at the locations shown in drawings provided by Lynx Consulting, Inc. The new equipment cabinet includes two HVAC units installed on the south side of the cabinet. These HVAC units are specified as AirSys UNICOOL Model 28V2B5MR410AAC units. Sound data for these units were obtained from the equipment specifications which include sound levels from normal operations and when the units are operating in “quiet mode.” The two new Comcast battery cabinets on the south side of the Site each have two temperature control units. Sound data for these units was not available at the time of this report. A similar unit was used in this analysis to estimate sound emissions from the new battery cabinets. There are two existing wall-mounted HVAC units on the north side of the existing equipment shelter. These units are Bard W36HB-A0ZZP4XXR 3-ton heat pumps. Sound data for these units was shown in the equipment specifications. December 8, 2022 Page 5 Comcast Kent Noise Study (206) 378-0569 www.greenbusch.com 1900 W Nickerson St., #201, Seattle, WA 98119  2262 N Albina Ave., #340 Portland, OR 97227 Sound data used in the acoustical model for the proposed and existing units are shown in Table 3. Table 3. Modeled Equipment Sound Levels Equipment Operating Mode Distance, feet Sound Level, dBA AirSys Model 28V2B5MR410AAC1 Normal Operation 6.5 68 Quiet Mode 62 Battery Cabinet2 Normal Operation 1.5 73 Bard W36HB- A0ZZPXXR3 Normal Operation 10 67 1. AIRSYS UNICOOL Specification Sheet Rev1.2. 2. Battery Cabinet Specification Sheet 3. Bard Wall-Mount Heat Pumps 1.5-5 Ton Capacity W18H-W60 Models 208V-460V 60hz Specification Book A 100-kW emergency generator will also be installed on the southeast side of the Site. Although the generator is assumed to be exempt from codified sound limits, it should only be exercised during daytime hours to minimize potential noise effects to nearby properties. RESULTS Predicted sound levels at adjacent properties from the proposed battery cabinets, the equipment cabinet cooling units operating normally, and the HVAC units on the existing equipment shelter are shown in Table 4. Table 4. Predicted Unmitigated Sound Levels, dBA Receiving Property Project Sound Limits (day/night) Predicted Sound Level Complies with Sound Limits? North 65/65 68 No, exceeds daytime and nighttime limits South 60/50 70 East 65 West 67 As shown in Table 4, predicted sound levels from the Site exceed the daytime and nighttime sound limits at all adjacent property lines. To reduce sound levels to within codified sound limits, the chain-link fence located on the west, south, and east sides of the Site should be replaced with a 9-foot-tall solid barrier. The west and east sides of the barrier should extend further north to meet the north property line. The northern portion of the chain-link fence should be replaced with a 6- foot-tall solid barrier. The gate does not need to be a solid barrier. The locations and heights of the recommended solid barriers are shown in Figure 2. Additionally, the new AirSys units should operate in “quiet mode.” The resulting sound levels with the addition of the solid barriers and AirSys units operating in “quiet mode” are shown in Table 5. December 8, 2022 Page 6 Comcast Kent Noise Study (206) 378-0569 www.greenbusch.com 1900 W Nickerson St., #201, Seattle, WA 98119  2262 N Albina Ave., #340 Portland, OR 97227 Figure 2. Locations and Heights of Solid Barriers Table 5. Predicted Mitigated Sound Levels, dBA Receiving Property Project Sound Limits (day/night) Predicted Sound Level Complies with Sound Limits? North 65/65 63 Yes South 60/50 50 East 49 West 50 Predicted sound levels with the addition of the solid barriers described above and the AirSys units operating in “quiet mode” comply with daytime and nighttime sound limits at all nearby properties. Figure 3 illustrates predicted mitigated sound levels five feet above grade. December 8, 2022 Page 7 Comcast Kent Noise Study (206) 378-0569 www.greenbusch.com 1900 W Nickerson St., #201, Seattle, WA 98119  2262 N Albina Ave., #340 Portland, OR 97227 Figure 3. Predicted Mitigated Sound Levels, dBA CONCLUSION Based on the information provided to our office by Lynx Consulting, Inc., sound produced by the proposed equipment is anticipated to be within codified sound limits at all nearby properties with the inclusion of the solid barriers described in this document and AirSys units operating in “quiet mode.” Respectfully submitted; Justin Morgan, INCE Lead Noise and Vibration Consultant