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HomeMy WebLinkAboutRS_KCESI2_Noise_Study_181207_v2.pdf p) 206.378.0569 f) 206.378-0641 www.greenbusch.com 1900 West Nickerson Street, Suite 201 Seattle, WA 98119 DATE: December 6, 2018 TO: Erik Waligorski, PE – Carollo Engineers, Inc. FROM: Drew J. Savas – The Greenbusch Group, Inc. RE: Eastside Interceptor Section 2 Rehabilitation Phase II – Noise Study Transmitted by: Mail Delivery Fax E-mail Erik: The intent of this memorandum is to present predicted sound levels during daytime and nighttime construction activities, compare predicted sound levels with regulatory criteria, recommend sound level limits and present potential mitigation for the Eastside Interceptor Section 2 Rehabilitation Phase II Project (“Project”) in Renton, Washington. Daytime construction activities will consist of bypass pumping, odor control, general construction, excavation, restoration, and pipe lining. Daytime activities will occur along the project alignment shown in Figure 1. Nighttime activities will consist of only bypass pumping and odor control in the North Staging Area. Nighttime activities are expected to normally require only three bypass pumps, while up to eight bypass pumps are anticipated during daytime hours. SUMMARY Daytime operations are expected to comply with the City of Renton and King County Guide Specification criteria. Nighttime operations are expected to exceed maximum permissible noise limits. Therefore, it is recommended that a noise variance be obtained from the City of Renton. The variance should allow a nighttime hourly LEQ up to 53 dBA 100 feet from the construction boundary or at EDNA Class A receptors when measured at the building envelop, whichever is further. Daytime operations should not exceed an hourly LEQ of 85 dBA 50 feet from the construction boundary or at residential-use receptors when measured at the building envelop, whichever is further. December 6, 2018 Page 2 Eastside Interceptor Section 2 Rehabilitation Phase II - Noise Study The Greenbusch Group, Inc. p) 206.378.0569 f) 206.378-0641 www.greenbusch.com 1900 West Nickerson Street, Suite 201 Seattle, WA 98119 NOMENCLATURE Decibel, dBA The auditory response to sound is a complex process that occurs over a wide range of frequencies and intensities. Decibel levels, or “dB,” are a form of shorthand that compresses this broad range of intensities with a convenient numerical scale. The decibel scale is logarithmic. For example, using the decibel scale, a doubling or halving of energy causes the sound level to change by 3 dB; it does not double or halve the sound loudness as might be expected. The minimum sound level variation perceptible to a human observer is generally around 3 dB. A 5-dB change is clearly perceptible, and an 8 to 10 dB change is associated with a perceived doubling or halving of loudness. The human ear has a unique response to sound pressure. It is less sensitive to those sounds falling outside the speech frequency range. Sound level meters and monitors utilize a filtering system to approximate human perception of sound. Measurements made utilizing this filtering system are referred to as “A weighted” and are called “dBA”. Table 1. A-weighted Levels of Common Sounds Sound Sound Level (dBA) Approximate Relative LoudnessA Jet Plane @ 100 feet 130 128 Rock Music with Amplifier 120 64 Thunder, Danger of Permanent Hearing Loss 110 32 Boiler Shop, Power Mower 100 16 Orchestral Crescendo at 25 feet 90 8 Busy Street 80 4 Interior of Department Store 70 2 Ordinary Conversation at 3 feet 60 1 Quiet Car at Low Speed 50 1/2 Average Office 40 1/4 City Residence, Interior 30 1/8 Quiet Country Residence, Interior 20 1/16 Rustle of Leaves 10 1/32 Threshold of Hearing 0 1/64 A As compared to ordinary conversation at 3 feet. Source: US Department of Housing and Urban Development, Aircraft Noise Impact Planning Guidelines for Local Agencies, November 1972. December 6, 2018 Page 3 Eastside Interceptor Section 2 Rehabilitation Phase II - Noise Study The Greenbusch Group, Inc. p) 206.378.0569 f) 206.378-0641 www.greenbusch.com 1900 West Nickerson Street, Suite 201 Seattle, WA 98119 Equivalent Sound Level, LAeq LAeq is the A-weighted level of a constant sound having the same energy content as the actual time-varying level during a specified interval. The LAeq is used to characterize complex, fluctuating sound levels with a single number. Typical intervals for LAeq are hourly, daily and annually. Sound Power Level, PWL Sound power is the amount of energy per second generated by a source, measured in watts. The sound power level (PWL) is a decibel representation with a reference value of 1 pico-watt (pW). Sound power is independent of distance, path, or influence from any nearby surfaces. Sound Pressure Level, SPL Sound pressure level correlates with what is heard by the human ear. SPL is defined as the squared ratio of the sound pressure with reference to 20 μPa. Sound pressure is affected by distance, path, barriers, directivity, etc. Percentage Sound Level, L(n) L(n) is the sound level that is exceeded n percent of the time; for example, L08 is the level exceeded 8% of the time. L25 is the sound level exceeded 25% of the time. REGULATORY CRITERIA Properties surrounding the project area consist of residential, commercial and industrial use. As of September 19th, 2018, the City of Renton no longer groups multiple zoning designations into noise districts called Environmental Designations for Noise Abatement (“EDNA”). Instead, the City has amended Section 8-7-4 of the Renton Municipal Code (“RMC”) to adopt Section 173-60-30 of the Washington Administrative Code (“WAC”). Section 173-60-030 of WAC states that EDNA classification will be defined by the property’s use. Generally, Class A EDNA includes residential use properties, Class B EDNA includes commercial use properties and Class C EDNA includes industrial use properties. Figure 1 provides a graphical representation of EDNAs in the Project area, along with the Project alignment. December 6, 2018 Page 4 Eastside Interceptor Section 2 Rehabilitation Phase II - Noise Study The Greenbusch Group, Inc. p) 206.378.0569 f) 206.378-0641 www.greenbusch.com 1900 West Nickerson Street, Suite 201 Seattle, WA 98119 Figure 1. Project Location and Nearby EDNAs Source: King County iMap, The Greenbusch Group, Inc., Bing Maps, City of Renton, Carollo Engineers, Inc. December 6, 2018 Page 5 Eastside Interceptor Section 2 Rehabilitation Phase II - Noise Study The Greenbusch Group, Inc. p) 206.378.0569 f) 206.378-0641 www.greenbusch.com 1900 West Nickerson Street, Suite 201 Seattle, WA 98119 Environmental Sound Level Limits City of Renton Maximum permissible environmental sound levels are defined by Section 8-7-2 of the RMC which adopts Section 173-60-040 of the WAC. These sound level limits are based on the EDNA the sound source originates from (EDNA of Sound Source) and in which EDNA the sound is received (EDNA of Receiving Property). A summary of the applicable sound level limits can be found in Table 2. Table 2. Environmental Sound Level Limits, L25 EDNA of Sound Source EDNA of Receiving Property Class A Class B Class C Class A 55 dBA 57 dBA 60 dBA Class B 57 dBA 60 dBA 65 dBA Class C 60 dBA 65 dBA 70 dBA Source: Section 8-7-2 City of Renton Municipal Code, Section 173-60-040 Washington Administrative Code Given the constant nature of bypass pumps and odor control equipment, hourly LEQ predictions are used to approximate L25 sound levels. Modifications Modifications to the environmental sound level limits set forth in Table 2 are also outlined in Section 173-60-040 of the WAC. These modifications are for certain times of day and classification of receiving properties. These modifications to the environmental sound level limits include the following: • 10 dBA reduction during the nighttime hours between the hours of 10 p.m. and 7 a.m. when the receiving property is within Class A EDNAs. Exemptions Section 173-60-050 of the WAC referenced by Section 8-7-2 of the RMC allows exemptions from environmental sound level limits set forth in Table 2. Applicable exemptions include all sounds originating from temporary construction sites as a result of construction activity that are received in Class B and Class C EDNAs, and in Class A EDNA between the hours of 7 a.m. and 10 p.m.. Construction activities that generate sounds received in Class A EDNAs between 10 p.m. and 7 a.m. would need to comply with sound level limits in Table 2. It is our interpretation of the RMC that all construction equipment, including bypass pumps and blowers, would qualify for this exemption. December 6, 2018 Page 6 Eastside Interceptor Section 2 Rehabilitation Phase II - Noise Study The Greenbusch Group, Inc. p) 206.378.0569 f) 206.378-0641 www.greenbusch.com 1900 West Nickerson Street, Suite 201 Seattle, WA 98119 PROJECT-SPECIFIC CRITERIA King County Guide Specification Section 01 35 43 defines sound level limits and general noise control requirements for the Project, as summarized below. • Sound Level Limits o Noise levels for scrapers, pavers, graders, and trucks shall not exceed 90 dBA and pile drivers shall not exceed 95 dBA at 50 feet as measured under the noisiest operating conditions. o For other equipment, noise levels shall not exceed 85 dBA. Equipment that cannot meet these levels shall be quieted by use of improved exhaust mufflers, noise attenuation barriers or other means. • General Noise Control Requirements o Noise complaints received by the Project Representative during the Work will be shared with the contractor. Work with the Project Representative, as required, to resolve noise related complaints. o Noisy operations shall be scheduled to minimize their impact. o Unless otherwise indicated through a noise variance, comply with local controls and noise level rules, regulations, and ordinances which apply to work performed. o Each internal combustion engine, used on the job or related to the job, shall be equipped with a muffler of a type recommended by the manufacturer. No internal combustion engine shall be operated without said muffler. o Use electric or hydraulic tools whenever practical to reduce noise. o Provide notification of special circumstances or emergency conditions that require work beyond the hours specified as follows: ▪ Notify the Project Representative and local authority in advance of any proposed extended work hours for preauthorization. Include a written request for authorization per Section 01 14 00 to perform work specified and the circumstances that warrant this request. Include any additional measures to mitigate noise generated by this construction activity if deemed necessary by the Project Representative. ▪ If an emergency situation occurs that warrants extended hours, notify the Project Representative immediately upon determining the need for this work. December 6, 2018 Page 7 Eastside Interceptor Section 2 Rehabilitation Phase II - Noise Study The Greenbusch Group, Inc. p) 206.378.0569 f) 206.378-0641 www.greenbusch.com 1900 West Nickerson Street, Suite 201 Seattle, WA 98119 ACOUSTICAL MODEL The primary tool used to predict sound levels at nearby properties during nighttime operations was a 3-D computer noise modeling 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 accounts for the effects of distance, topography, and surface reflections on sound levels. Locations and sound power levels of anticipated equipment used during nighttime operations were determined from project drawings and information provided by vendors via Carollo Engineers, Inc. Three electric bypass pumps and one odor control unit are anticipated for nighttime operations. Topography, building locations and locations of property lines were determined from King County GIS records, Bing Maps, and Google Maps. Table 3. Bypass Pumping and Odor Control Equipment Sound Levels Equipment Sound Power Level Electric Bypass Pump 97 LwA Odor Control Unit 74 LwA Source: Equipment Vendors, Carollo Engineers, Inc. Figure 2. Modeled Equipment Locations Source: The Greenbusch Group, Inc., Bing Maps, Carollo Engineers, Inc. December 6, 2018 Page 8 Eastside Interceptor Section 2 Rehabilitation Phase II - Noise Study The Greenbusch Group, Inc. p) 206.378.0569 f) 206.378-0641 www.greenbusch.com 1900 West Nickerson Street, Suite 201 Seattle, WA 98119 ANALYSIS AND MITIGATION Nighttime – Bypass Pumping & Odor Control Nighttime activities are expected to occur at the North Staging Area and consist of only bypass pumping and odor control. While up to eight electric bypass pumps may operate during daytime hours, only three are anticipated during nighttime hours, apart from any emergency periods. The odor control unit will operate continuously during nighttime hours. These nighttime activities are predicted to exceed 50 dBA at some nearby Class A EDNA receptors. Therefore, mitigation and a noise variance from the City of Renton will need to be obtained. Predicted sound levels without mitigation from nighttime operations are presented in Table 4 and Figure 3. Additionally, as requested by the City of Renton, predicted unmitigated sound levels 300 feet from the electric bypass pumps are included and can be found in Table 5. Table 4. Unmitigated Predicted Nighttime Operation Sound Levels Receiving Property EDNA Predicted Sound Level, LEQ Nighttime Sound Level Limit, L25A Gene Coulon Beach Park Class A 38 dBA 50 dBA The Bristol at Southport Class A 51 dBA 50 dBA Southport on Lake Washington Class B 46 dBA None The Reserve Apartments Class A 56 dBA 50 dBA A City of Renton Nighttime Sound Level Limits Table 5. Unmitigated Predicted Nighttime Operation Sound Levels at 300 feetA Receiving Location Predicted Sound Level, LEQ North 55 dBA West 55 dBA East 55 dBA South 57 dBA A When measured from the bypass pumps. December 6, 2018 Page 9 Eastside Interceptor Section 2 Rehabilitation Phase II - Noise Study The Greenbusch Group, Inc. p) 206.378.0569 f) 206.378-0641 www.greenbusch.com 1900 West Nickerson Street, Suite 201 Seattle, WA 98119 Figure 3. Predicted Unmitigated Nighttime Sound Levels, dBA Source: The Greenbusch Group, Inc., Google Maps, City of Renton, Carollo Engineer, Inc. Predicted unmitigated sound levels from nighttime operations exceed regulatory criteria at nearby EDNA Class A properties. Therefore, it is recommended that a noise variance from the City of Renton be obtained. The noise variance should allow a nighttime hourly LEQ up to 53 dBA 100 feet from the construction boundary or at EDNA Class A receptors when measured at the building envelop, whichever is further. The recommended sound level limits could be achieved by using only the northern three bypass pumps during night operations and placing a noise barrier between these bypass pumps and The Reserve Apartments. The barrier should be constructed such that the pumps are not visible from anywhere on The Reserve Apartment’s parcel. The barrier should include two sheets of ¾ inch plywood with at least a 2 inch air gap between the sheets or outdoor noise curtains with a mass of at least 2 pounds per square foot attached to a fence. Appendix A includes a Specification Data Sheet for a typical outdoor noise curtain which could be used in this instance. The barrier should be placed as close to the pumps as possible and be approved by a Structural Engineer. Reserve Apartments Southport on Lake Wash. Bristol at Southport 300’ from Pumps December 6, 2018 Page 10 Eastside Interceptor Section 2 Rehabilitation Phase II - Noise Study The Greenbusch Group, Inc. p) 206.378.0569 f) 206.378-0641 www.greenbusch.com 1900 West Nickerson Street, Suite 201 Seattle, WA 98119 A modeled barrier with a length of 50 feet, a height of 8 feet, and spaced 6 feet from the pumps as seen in Figure 4 was used to predict the effectiveness of the described noise barrier. Predicted sound levels with the modeled noise barrier are presented in Table 6 and Figure 5. Predicted mitigated sound levels 300 feet from the electric bypass pumps can be found in Table 7. Table 6. Mitigated Predicted Nighttime Operation Sound Levels Receiving Property EDNA Predicted Sound Level, LEQ Nighttime Sound Level Limit, L25A Gene Coulon Beach Park Class A 40 dBA 50 dBA The Bristol at Southport Class A 53 dBA 50 dBA Southport on Lake Washington Class B 48 dBA None The Reserve Apartments Class A 42 dBA 50 dBA A City of Renton Nighttime Sound Level Limits Table 7. Mitigated Predicted Nighttime Operation Sound Levels at 300 feetA Receiving Location Predicted Sound Level, LEQ North 57 dBA West 56 dBA East 55 dBA South 54 dBA A When measured from the bypass pumps. December 6, 2018 Page 11 Eastside Interceptor Section 2 Rehabilitation Phase II - Noise Study The Greenbusch Group, Inc. p) 206.378.0569 f) 206.378-0641 www.greenbusch.com 1900 West Nickerson Street, Suite 201 Seattle, WA 98119 Figure 4. Modeled Noise Barrier, South Facing Source: The Greenbusch Group, Inc., Google Maps, Carollo Engineers, Inc Reserve Apartments Noise Barrier Bypass Pumps December 6, 2018 Page 12 Eastside Interceptor Section 2 Rehabilitation Phase II - Noise Study The Greenbusch Group, Inc. p) 206.378.0569 f) 206.378-0641 www.greenbusch.com 1900 West Nickerson Street, Suite 201 Seattle, WA 98119 Figure 5. Predicted Mitigated Nighttime Sound Levels, dBA Source: The Greenbusch Group, Inc., Google Maps, City of Renton, Carollo Engineer, Inc. In the event of noise complaints from properties north of the North Staging Area, a noise barrier could be placed on all sides of the active bypass pumps. This noise barrier should be of the same construction as the noise barrier previously described. If the barrier is constructed of plywood, acoustical absorption should be placed on the interior walls. Daytime – Construction & Linabond Construction, restoration, and the Linabond pipe-lining process are expected to occur only during weekday, daytime hours and are therefore exempt from the City of Renton sound level limits. Bypass pumping and odor control will occur continuously during daytime hours and is also exempt from the City of Renton sound level limits. All daytime operations will be required to satisfy King County’s Guide Specification sound level limits. Sound originating from equipment or construction activity during daytime is assessed at 50 feet, per Section 01 35 43 of the Guide Specification. Anticipated daytime equipment and their respective sound levels can be found in Table 8. Reserve Apartments Southport on Lake Wash. Bristol at Southport 300’ from Pumps December 6, 2018 Page 13 Eastside Interceptor Section 2 Rehabilitation Phase II - Noise Study The Greenbusch Group, Inc. p) 206.378.0569 f) 206.378-0641 www.greenbusch.com 1900 West Nickerson Street, Suite 201 Seattle, WA 98119 Table 8. Construction Equipment Sound Levels Equipment Sound Level at 50’ Sound Level Limit at 50’ C Construction Front End Loader 80 dBA A 85 dBA Excavator 85 dBA A 85 dBA Back Hoe 80 dBA A 85 dBA Concrete Saw 90 dBA A 90 dBA Vibratory Pile Driver 95 dBA A 95 dBA Impact Pile Driver 95 dBA A 95 dBA Linabond System Supply and Spray-Rig Truck NA 85 dBA 300 kW Genset 82 dBA A 85 dBA 150 kW In-Line Heater 85 dBA A 85 dBA 10 HP Blower 85 dBA A 85 dBA 5000 CFM Dehumidifier 85 dBA A 85 dBA 1000 CFM Air Scrubber <85 dBA A 85 dBA Bypass Pumping and Odor Control Electric Bypass Pump 65 dBA B 85 dBA Odor Control Unit 42 dBA B 85 dBA A Table 9.1 FHWA Construction Noise and Vibration Handbook (LSmax) B Carollo Engineers, Inc. C King County Guide Specification Section 01 35 43 All daytime equipment and activities are expected to satisfy King County Guide Specification sound level limits. However, the King County Guide Specification only sets criteria for each piece of operating equipment and does not consider the cumulative sound levels of all operating equipment. Therefore, it is recommended that sound originating from daytime construction activities and the Linabond system not exceed an hourly LEQ of 85 dBA 50 feet from the construction boundary or at residential-use receptors when measured at the building envelop, whichever is further. It is recommended that the contractor implement the following to help meet the recommended sound level limits: • Use only ambient-sensing broadband back-up alarms and minimize backing. • Noisy equipment and construction activities should be placed or performed as far as possible from noise sensitive receptors. December 6, 2018 Page 14 Eastside Interceptor Section 2 Rehabilitation Phase II - Noise Study The Greenbusch Group, Inc. p) 206.378.0569 f) 206.378-0641 www.greenbusch.com 1900 West Nickerson Street, Suite 201 Seattle, WA 98119 • Monitor noise levels during construction. Additionally, the following may be implemented if further mitigation is required to meet the recommended sound level limits: • Limit engine idling to 5 minutes or less. • Use radios for long-range communication; only use raised voices and public address systems in an emergency. • Use upgraded engine exhaust mufflers, engine shrouds, or sound enclosures on noisier equipment. • Install noise barrier or noise curtains of similar design to what is previously described around noisier equipment. • Use electric and hydraulic equipment in lieu of diesel of pneumatic equipment. • Perform impact work during times of high ambient sound levels. Emergency Periods – Daytime and Nighttime The RMC adopts Section 173-60-050 of the WAC. Section 173-60-050 of the WAC exempts all sound created by emergency equipment and work necessary for the health, safety and welfare of the community. It is our interpretation that additional bypass pumping and the use of backup generators during emergency periods would be exempt from the City of Renton sound level limits. Appendix A Noise Curtain Specification Data Sheet Spec Data Sheet NOISE BARRIERS BBC-SERIES NOISE BARRIERS/SOUND ABSORBER COMPOSITES 50 H.P. Almgren Drive  Agawam, MA 01001  Ph 413.789.1770 fax 413.789.2248 www.soundseal.com BBC-13X-2 LB-2”Sound Curtains Sound Seal’s BBC-13X-2 LB-2” offers the benefits of both a noise barrier and a sound absorber for outdoor applications. This product consists of a two-inch thick vinyl-coated- fiberglass-cloth faced quilted fiberglass that is bonded to a two-pound per sq. ft. reinforced loaded vinyl noise barrier. “X” style Sound Curtain panels are constructed with grommets across the top and bottom, and exterior grade Velcro seals along the vertical edges. The product is also available in roll form with edges bound or unbound.  Class A (or 1) flammability rated per ASTM E- 84  For Indoor or Outdoor Applications  Available facing colors on quilt: gray, tan, black or off-white  Available barrier colors: gray, tan, blue or olive drab Applications: With its 7+ year life span* in the harshest environments, this product is typically used as a temporary noise barrier on outdoor applications such as construction site noise mitigation projects. Also available with a one-pound psf noise barrier or a one-inch thick quilted fiberglass sound absorber. Product Data: Description Vinyl coated fiberglass cloth facing on 2” quilted fiberglass/ 2 lb-psf reinforced loaded vinyl noise barrier Flammability Flame Spread: 23.0 Smoke density: 30.0 Nominal thickness 2.0 inches Temperature range -20 to +180 F Standard roll size 54” wide x 25’ long Weight ` 2.45 lb psf Acoustical Performance: Sound Transmission Loss OCTAVE BAND FREQUENCIES (Hz) Product 125 250 500 1000 2000 4000 STC BBC-13X-2lb-2” 19 25 33 46 53 58 37 ASTM E-90 & E 413 Sound Absorption Data OCTAVE BAND FREQUENCIES (Hz) Product 125 250 500 1000 2000 4000 NRC BBC-13X-2lb-2” .07 .27 .96 1.13 1.08 .99 .85 ASTM C 423 * when properly installed.