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2019-126 DEC Noise UpdateDate: June 14, 2019 Report No. 2019-126 INFORMAL STAFF REPORT TO MAYOR AND CITY COUNCIL SUBJECT: The purpose of this report is to provide the City Council with information regarding predictive noise modeling and staff public comments related to noise that were made during the planning and public involvement phase of the power plant projects. BACKGROUND: During the May 21rst City Council meeting a question was asked regarding whether or not predictive sound modeling was done during the planning phase of the Denton Energy Center (DEC). A follow up question involved public comments possibly made by DME staff addressing the potential noise impacts of the DEC. CONCLUSION: Burns and McDonnell did perform predictive sound modeling of both proposed sites. A memo summarizing the results of the modeling for 12 engines at the Jim Christal site is attached to this report. The City of Denton does not have a defined industrial noise code. The City does have a residential noise code which establishes the limit at 65dB. Based on this threshold, noise controls were included in the design to ensure the sound levels at the property lines did not exceed the threshold. Summary of the Predictive modeling prepared by Burns and McDonnell (12 engines Jim Christal): No sound reduction measures taken would result in 70.7 dB of noise at nearest residence. Installing 35 dB silencers on engine exhaust and utilizing Ultra Low Noise radiators would result in a sound level of 50.5 dB at nearest residence (predictive modeling). Jim Christal site modeling results are summarized on page 11, table 3. A sound contour graph was included on page 19. Staff reviewed past PUB and CC agendas, meeting minutes, and where available, recordings of meetings. The potential sound impacts of the proposed Green Valley site were discussed in a Saturday public forum held at the Council Chambers on January 23, 2016. The potential sound impacts of the Jim Christal site were not discussed. The memo and documents that were presented at the meeting also contained information about the Jim Christal site. The memo is attached to this report and a link to the video is below. Link to public meeting: A question regarding the potential noise impacts of the proposed Green Valley site was asked by Gary Steel on January 23, 2016 during the RDP public forum. At 33:30 in the video, Mr. Steel questions staff about the noise impacts on the surrounding homes and businesses. It was answered by Mary Davis with Burns and McDonnell. https://dentontx.new.swagit.com/videos/13207 Please do not hesitate to contact me if you have any further questions about any noise related issues with the DEC. Date: June 14, 2019 Report No. 2019-126 ATTACHMENT(S): DEC Noise Memo 1-8-2016.pdf STAFF CONTACT: Chris Lutrick, DME (940) 349-7152 Chris.Lutrick@cityofdenton.com This document and any attachments thereto may contain information that is confidential, commercially-sensitive, proprietary, and/or public power utility competitive and financial information in accordance with the provisions of Texas Government Code, Section 552.101, 552.104, 552.110 and/or 552.133, and may be protected from required public disclosure. Memorandum Date: January 8, 2016 To: Mary Hauner-Davis, Burns & McDonnell From: Tess Fuller, Burns & McDonnell Subject: Denton Municipal Noise Modeling A noise analysis has been performed as part of the permitting efforts for Denton Municipal Electric’s (DME) reciprocating engine power generating facility at the proposed Denton Energy Center. Ambient measurements were taken to determine the existing sound levels in the areas of the proposed generating facilities. In December of 2015, initial noise modeling was performed for the power generation facility with 12 engines in the model. Sound levels used in the noise models were estimated based on previous project information. Also, 15 decibels (dB) of attenuation was added for the reciprocating engine sources that were expected to be located inside a building. In that analysis, un-attenuated inlet vents and stacks were analyzed, as well as stacks and intake vents with 35 decibels (dB) of attenuation. The manufacturers exhaust gas silencer (stack) from all potential vendors is rated for 35 dB of attenuation. While no specific data was obtained from manufacturers for the silencers for the charge (inlet) air silencers, the bid specification requires 35 dBA of sound attenuation. For full results of this analysis, please see Attachment A for the original memo. Since that memorandum has been developed, DME requested that Burns & McDonnell perform modeling with low or ultra-low sound fans on the radiators for comparison with the standard sound attention that has already been modeled. The predicted sound level results for the Denton Energy Center (6-engine site) without attenuation on the fans, but including the bid-package requirement of 35 dB of attenuation at the intake vents and stacks are shown in Table 1. Resulting sound levels with low- and ultra-low sound fans on the radiators are discussed in further tables. The modeling layout and nearby residences for which noise levels were predicted are shown in Attachment B. January 8, 2016 Page 2 This document and any attachments thereto may contain information that is confidential, commercially- sensitive, proprietary, and/or public power utility competitive and financial information in accordance with the provisions of Texas Government Code, Section 552.101, 552.104, 552.110 and/or 552.133, and may be protected from required public disclosure. Memorandum (cont’d) Table 1: Denton Energy Center (6-Engine Site) Sound Levels with Attenuated Air Inlets and Stacks Onlya Time Period Measurement Point Measured L90 Modeled Facility With Attenuation Expected New Sound Levels Increase Over Ambient (dBA) (dBA) (dBA) (dBA) 11:00 AM - 1:00 PM Res1 40.9 48.8 49.5 8.6 Res2 40.9 47.2 48.1 7.2 Res3 40.9 43.9 45.7 4.8 Res4 40.9 43.2 45.2 4.3 Res5 47.1 48.6 50.9 3.8 Res6 47.1 48.5 50.9 3.8 Res7 47.1 48.0 50.6 3.5 Res8 47.1 47.3 50.2 3.1 5:00 PM - 7:00 PM Res1 41.4 48.8 49.5 8.1 Res2 41.4 47.2 48.2 6.8 Res3 41.4 43.9 45.8 4.4 Res4 41.4 43.2 45.4 4.0 Res5 40.2 48.6 49.2 9.0 Res6 40.2 48.5 49.1 8.9 Res7 40.2 48.0 48.7 8.5 Res8 40.2 47.3 48.1 7.9 11:00 PM - 1:00 AM Res1 45.0 48.8 50.3 5.3 Res2 45.0 47.2 49.2 4.2 Res3 45.0 43.9 47.5 2.5 Res4 45.0 43.2 47.2 2.2 Res5 48.4 48.6 51.5 3.1 Res6 48.4 48.5 51.5 3.1 Res7 48.4 48.0 51.2 2.8 Res8 48.4 47.3 50.9 2.5 5:00 AM - 7:00 AM Res1 44.4 48.8 50.1 5.7 Res2 44.4 47.2 49.0 4.6 Res3 44.4 43.9 47.2 2.8 Res4 44.4 43.2 46.9 2.5 Res5 45.2 48.6 50.2 5.0 Res6 45.2 48.5 50.2 5.0 Res7 45.2 48.0 49.8 4.6 Res8 45.2 47.3 49.4 4.2 (a) Using a 6-engine site For reference, sound is measured on a logarithmic scale, and thus, cannot be analyzed linearly. A 10-dB increase is a perceived doubling of sound levels. A 3-dB increase or decrease is January 8, 2016 Page 3 This document and any attachments thereto may contain information that is confidential, commercially- sensitive, proprietary, and/or public power utility competitive and financial information in accordance with the provisions of Texas Government Code, Section 552.101, 552.104, 552.110 and/or 552.133, and may be protected from required public disclosure. Memorandum (cont’d) considered a barely perceivable difference and a 5-dB change in sound levels is considered a clearly noticeable change. As shown in the Tables above, the model predicts a maximum of a 9.0 dB increase at the Denton Energy Center. Predicted sound level contours from the Denton Energy Center without attenuation for the fans, shown in 5-dB increments, is included in Attachment C. Low-sound fans for the radiators were also analyzed to determine how their use would impact sound levels at the nearest residences. The results from this analysis are shown below in Table 2. Table 2: Denton Energy Center (6-Engine Site) Sound Levels with Attenuated Air Inlets and Stacks and Low-Sound Fans on Radiatorsa Time Period Measurement Point Measured L90 Modeled Facility With Attenuation Expected New Sound Levels Increase Over Ambient (dBA) (dBA) (dBA) (dBA) 11:00 AM - 1:00 PM Res1 40.9 44.5 46.1 5.2 Res2 40.9 43.1 45.1 4.2 Res3 40.9 40.1 43.5 2.6 Res4 40.9 39.5 43.3 2.4 Res5 47.1 44.2 48.9 1.8 Res6 47.1 44.0 48.8 1.7 Res7 47.1 43.6 48.7 1.6 Res8 47.1 42.8 48.5 1.4 5:00 PM - 7:00 PM Res1 41.4 44.5 46.2 4.8 Res2 41.4 43.1 45.3 3.9 Res3 41.4 40.1 43.8 2.4 Res4 41.4 39.5 43.6 2.2 Res5 40.2 44.2 45.7 5.5 Res6 40.2 44.0 45.5 5.3 Res7 40.2 43.6 45.2 5.0 Res8 40.2 42.8 44.7 4.5 11:00 PM - 1:00 AM Res1 45.0 44.5 47.8 2.8 Res2 45.0 43.1 47.2 2.2 Res3 45.0 40.1 46.2 1.2 Res4 45.0 39.5 46.1 1.1 Res5 48.4 44.2 49.8 1.4 Res6 48.4 44.0 49.7 1.3 Res7 48.4 43.6 49.6 1.2 Res8 48.4 42.8 49.5 1.1 January 8, 2016 Page 4 This document and any attachments thereto may contain information that is confidential, commercially- sensitive, proprietary, and/or public power utility competitive and financial information in accordance with the provisions of Texas Government Code, Section 552.101, 552.104, 552.110 and/or 552.133, and may be protected from required public disclosure. Memorandum (cont’d) Time Period Measurement Point Measured L90 Modeled Facility With Attenuation Expected New Sound Levels Increase Over Ambient (dBA) (dBA) (dBA) (dBA) 5:00 AM - 7:00 AM Res1 44.4 44.5 47.5 3.1 Res2 44.4 43.1 46.8 2.4 Res3 44.4 40.1 45.8 1.4 Res4 44.4 39.5 45.6 1.2 Res5 45.2 44.2 47.7 2.5 Res6 45.2 44.0 47.7 2.5 Res7 45.2 43.6 47.5 2.3 Res8 45.2 42.8 47.2 2.0 (a) Using a 6-engine site The attenuated sound levels are noticeably lower than those without attenuation on the radiator fans, with a maximum increase of 5.5 dB for the Denton Energy Center (6-engine site). Predicted sound level contours from the Denton Energy Center with the low sound fans, shown in 5-dB increments, is included in Attachment C. Ultra-low sound fans were also analyzed for the radiators at the Denton Energy Center site (6- engine site). The results from this analysis are shown below in Table 3. Table 3: Denton Energy Center (6-Engine Site) Sound Levels with Attenuated Air Inlets and Stacks and Ultra-Low Sound Fans on Radiatorsa Time Period Measurement Point Measured L90 Modeled Facility With Attenuation Expected New Sound Levels Increase Over Ambient (dBA) (dBA) (dBA) (dBA) 11:00 AM - 1:00 PM Res1 40.9 43.5 45.4 4.5 Res2 40.9 42.2 44.6 3.7 Res3 40.9 39.3 43.2 2.3 Res4 40.9 38.8 43.0 2.1 Res5 47.1 43.1 48.6 1.5 Res6 47.1 42.9 48.5 1.4 Res7 47.1 42.5 48.4 1.3 Res8 47.1 41.7 48.2 1.1 January 8, 2016 Page 5 This document and any attachments thereto may contain information that is confidential, commercially- sensitive, proprietary, and/or public power utility competitive and financial information in accordance with the provisions of Texas Government Code, Section 552.101, 552.104, 552.110 and/or 552.133, and may be protected from required public disclosure. Memorandum (cont’d) Time Period Measurement Point Measured L90 Modeled Facility With Attenuation Expected New Sound Levels Increase Over Ambient (dBA) (dBA) (dBA) (dBA) 5:00 PM - 7:00 PM Res1 41.4 43.5 45.6 4.2 Res2 41.4 42.2 44.8 3.4 Res3 41.4 39.3 43.5 2.1 Res4 41.4 38.8 43.3 1.9 Res5 40.2 43.1 44.9 4.7 Res6 40.2 42.9 44.8 4.6 Res7 40.2 42.5 44.5 4.3 Res8 40.2 41.7 44.0 3.8 11:00 PM - 1:00 AM Res1 45.0 43.5 47.3 2.3 Res2 45.0 42.2 46.8 1.8 Res3 45.0 39.3 46.0 1.0 Res4 45.0 38.8 45.9 0.9 Res5 48.4 43.1 49.5 1.1 Res6 48.4 42.9 49.5 1.1 Res7 48.4 42.5 49.4 1.0 Res8 48.4 41.7 49.2 0.8 5:00 AM - 7:00 AM Res1 44.4 43.5 47.0 2.6 Res2 44.4 42.2 46.4 2.0 Res3 44.4 39.3 45.6 1.2 Res4 44.4 38.8 45.5 1.1 Res5 45.2 43.1 47.3 2.1 Res6 45.2 42.9 47.2 2.0 Res7 45.2 42.5 47.1 1.9 Res8 45.2 41.7 46.8 1.6 (a) Using a 6-engine site The attenuated sound levels are slightly lower than those with the low sound fans, with a maximum increase of 4.7 dB (versus a maximum increase of 5.5 dB over existing levels with the low-sound fans). Predicted sound level contours from the Denton Energy Center (6-Engine Site) with the low sound fans, shown in 5-dB increments, is included in Attachment C. TEF cc: Rob Everard, Burns & McDonnell ATTACHMENT A DECEMBER 2015 MEMORANDUM This document and any attachments thereto may contain information that is confidential, commercially-sensitive, proprietary, and/or public power utility competitive and financial information in accordance with the provisions of Texas Government Code, Section 552.101, 552.104, 552.110 and/or 552.133, and may be protected from required public disclosure. Memorandum Date: December 14, 2015 To: Mary Hauner-Davis, Burns & McDonnell From: Tess Fuller, Burns & McDonnell Subject: Denton Municipal Noise Modeling A noise analysis has been performed as part of the permitting efforts for Denton Municipal Electric’s (DME) two reciprocating engine power generating facilities at the proposed Denton Energy Center and Green Valley Energy Center. Ambient measurements were taken at both sites to determine the existing sound levels in the areas of the proposed generating facilities. Noise modeling was also performed for each power generation facility. Sound levels were estimated based on previous project information. Also, 15 decibels (dB) of attenuation was added for the reciprocating engine sources that are expected to be located inside a building. Noise model layouts for each facility is located in Attachment A. Measured ambient sound levels, along with projected facility sound levels without attenuation (in A-weighted decibels [dBA]) at the nearest residences are below in Table 1 and Table 2 for Denton Energy Center (12 engines) and Green Valley Energy Center (7 engines), respectively. Table 1: Denton Energy Center Sound Levels without Attenuation* Time Period Measurement Point Measured L90 Modeled Facility Expected New Sound Levels Increase Over Ambient (dBA) (dBA) (dBA) (dBA) 11:00 AM - 1:00 PM Res1 40.9 72.1 72.1 31.2 Res2 40.9 70.7 70.7 29.8 Res3 40.9 67.1 67.1 26.2 Res4 40.9 66.5 66.5 25.6 Res5 47.1 70.2 70.2 23.1 Res6 47.1 71.0 71.0 23.9 Res7 47.1 70.8 70.8 23.7 Res8 47.1 70.0 70.0 22.9 5:00 PM - 7:00 PM Res1 41.4 72.1 72.1 30.7 Res2 41.4 70.7 70.7 29.3 Res3 41.4 67.1 67.1 25.7 Res4 41.4 66.5 66.5 25.1 Res5 40.2 70.2 70.2 30.0 Res6 40.2 71.0 71.0 30.8 Res7 40.2 70.8 70.8 30.6 Res8 40.2 70.0 70.0 29.8 December 14, 2015 Page 2 This document and any attachments thereto may contain information that is confidential, commercially- sensitive, proprietary, and/or public power utility competitive and financial information in accordance with the provisions of Texas Government Code, Section 552.101, 552.104, 552.110 and/or 552.133, and may be protected from required public disclosure. Memorandum (cont’d) Time Period Measurement Point Measured L90 Modeled Facility Expected New Sound Levels Increase Over Ambient (dBA) (dBA) (dBA) (dBA) 11:00 PM - 1:00 AM Res1 45.0 72.1 72.1 27.1 Res2 45.0 70.7 70.7 25.7 Res3 45.0 67.1 67.1 22.1 Res4 45.0 66.5 66.5 21.5 Res5 48.4 70.2 70.2 21.8 Res6 48.4 71.0 71.0 22.6 Res7 48.4 70.8 70.8 22.4 Res8 48.4 70.0 70.0 21.6 5:00 AM - 7:00 AM Res1 44.4 72.1 72.1 27.7 Res2 44.4 70.7 70.7 26.3 Res3 44.4 67.1 67.1 22.7 Res4 44.4 66.5 66.5 22.1 Res5 45.2 70.2 70.2 25.0 Res6 45.2 71.0 71.0 25.8 Res7 45.2 70.8 70.8 25.6 Res8 45.2 70.0 70.0 24.8 *Sounds levels based on 12 engines at the Denton Energy Center location. December 14, 2015 Page 3 This document and any attachments thereto may contain information that is confidential, commercially- sensitive, proprietary, and/or public power utility competitive and financial information in accordance with the provisions of Texas Government Code, Section 552.101, 552.104, 552.110 and/or 552.133, and may be protected from required public disclosure. Memorandum (cont’d) Table 2: Green Valley Energy Center Sound Levels* Time Period Measurement Point Measured L90 Modeled Facility Expected New Sound Levels Increase Over Ambient (dBA) (dBA) (dBA) (dBA) 11:00 AM - 1:00 PM Res1 42.5 62.1 62.1 19.6 Res2 42.5 63.3 63.3 20.8 Res3 42.5 63.3 63.3 20.8 Res4 42.5 64.2 64.2 21.7 Res5 42.5 63.4 63.4 20.9 Res6 42.5 68.4 68.4 25.9 Res7 40.7 70.7 70.7 30.0 Res8 38.9 72.8 72.8 33.9 Res9 38.9 70.8 70.8 31.9 Res10 38.9 67.4 67.4 28.5 Res11 38.9 66.9 66.9 28.0 Res12 38.9 66.2 66.2 27.3 Res13 38.9 65.5 65.5 26.6 Res14 38.9 70.3 70.3 31.4 5:00 PM - 7:00 PM Res1 47.1 62.1 62.2 15.1 Res2 47.1 63.3 63.4 16.3 Res3 47.1 63.3 63.4 16.3 Res4 47.1 64.2 64.3 17.2 Res5 47.1 63.4 63.5 16.4 Res6 47.1 68.4 68.4 21.3 Res7 46.9 70.7 70.7 23.8 Res8 46.7 72.8 72.8 26.1 Res9 46.7 70.8 70.8 24.1 Res10 46.7 67.4 67.4 20.7 Res11 46.7 66.9 66.9 20.2 Res12 46.7 66.2 66.2 19.5 Res13 46.7 65.5 65.6 18.9 Res14 46.7 70.3 70.3 23.6 December 14, 2015 Page 4 This document and any attachments thereto may contain information that is confidential, commercially- sensitive, proprietary, and/or public power utility competitive and financial information in accordance with the provisions of Texas Government Code, Section 552.101, 552.104, 552.110 and/or 552.133, and may be protected from required public disclosure. Memorandum (cont’d) Time Period Measurement Point Measured L90 Modeled Facility Expected New Sound Levels Increase Over Ambient (dBA) (dBA) (dBA) (dBA) 11:00 PM - 1:00 AM Res1 45.2 62.1 62.2 17.0 Res2 45.2 63.3 63.4 18.2 Res3 45.2 63.3 63.4 18.2 Res4 45.2 64.2 64.3 19.1 Res5 45.2 63.4 63.5 18.3 Res6 45.2 68.4 68.4 23.2 Res7 45.3 70.7 70.7 25.5 Res8 45.3 72.8 72.8 27.5 Res9 45.3 70.8 70.8 25.5 Res10 45.3 67.4 67.4 22.1 Res11 45.3 66.9 66.9 21.6 Res12 45.3 66.2 66.2 20.9 Res13 45.3 65.5 65.5 20.2 Res14 45.3 70.3 70.3 25.0 5:00 AM - 7:00 AM Res1 50.4 62.1 62.4 12.0 Res2 50.4 63.3 63.5 13.1 Res3 50.4 63.3 63.5 13.1 Res4 50.4 64.2 64.4 14.0 Res5 50.4 63.4 63.6 13.2 Res6 50.4 68.4 68.5 18.1 Res7 47.4 70.7 70.7 23.4 Res8 44.3 72.8 72.8 28.5 Res9 44.3 70.8 70.8 26.5 Res10 44.3 67.4 67.4 23.1 Res11 44.3 66.9 66.9 22.6 Res12 44.3 66.2 66.2 21.9 Res13 44.3 65.5 65.5 21.2 Res14 44.3 70.3 70.3 26.0 *Sound levels based on 7 engines at the Green Valley Energy Center. Sound is measured on a logarithmic scale, and thus, cannot be analyzed linearly. A 10-dB increase is a perceived doubling of sound levels. A 3-dB increase or decrease is considered a barely perceivable difference and a 5-dB change in sound levels is considered a clearly noticeable change. As shown in the Tables above, the un-attenuated facility predicts a maximum of a 31.2 dB increase at the Denton Energy Center and a 33.9-dB increase at the Green Valley Energy Center. The manufacturers exhaust gas silencer (stack) from all potential vendors is rated for 35 dB of attenuation. While no specific data has been obtained from manufacturers for the silencers for December 14, 2015 Page 5 This document and any attachments thereto may contain information that is confidential, commercially- sensitive, proprietary, and/or public power utility competitive and financial information in accordance with the provisions of Texas Government Code, Section 552.101, 552.104, 552.110 and/or 552.133, and may be protected from required public disclosure. Memorandum (cont’d) the charge (inlet) air silencers, the bid specification requires 35 dBA of sound attenuation. When 35 dB of attenuation is added, the sound levels are reduced at the residential areas, as shown below in Table 3 and Table 4, below. Table 3: Denton Energy Center Sound Levels with Attenuated Inlets and Stacks Time Period Measurement Point Measured L90 Modeled Facility With Attenuation Expected New Sound Levels Increase Over Ambient (dBA) (dBA) (dBA) (dBA) 11:00 AM - 1:00 PM Res1 40.9 51.4 51.8 10.9 Res2 40.9 49.7 50.2 9.3 Res3 40.9 46.5 47.6 6.7 Res4 40.9 45.9 47.1 6.2 Res5 47.1 51.6 52.9 5.8 Res6 47.1 51.5 52.8 5.7 Res7 47.1 51.0 52.5 5.4 Res8 47.1 50.3 52.0 4.9 5:00 PM - 7:00 PM Res1 41.4 51.4 51.8 10.4 Res2 41.4 49.7 50.3 8.9 Res3 41.4 46.5 47.7 6.3 Res4 41.4 45.9 47.2 5.8 Res5 40.2 51.6 51.9 11.7 Res6 40.2 51.5 51.8 11.6 Res7 40.2 51.0 51.3 11.1 Res8 40.2 50.3 50.7 10.5 11:00 PM - 1:00 AM Res1 45.0 51.4 52.3 7.3 Res2 45.0 49.7 51.0 6.0 Res3 45.0 46.5 48.8 3.8 Res4 45.0 45.9 48.5 3.5 Res5 48.4 51.6 53.3 4.9 Res6 48.4 51.5 53.2 4.8 Res7 48.4 51.0 52.9 4.5 Res8 48.4 50.3 52.5 4.1 5:00 AM - 7:00 AM Res1 44.4 51.4 52.2 7.8 Res2 44.4 49.7 50.8 6.4 Res3 44.4 46.5 48.6 4.2 Res4 44.4 45.9 48.2 3.8 Res5 45.2 51.6 52.5 7.3 Res6 45.2 51.5 52.4 7.2 Res7 45.2 51.0 52.0 6.8 Res8 45.2 50.3 51.5 6.3 December 14, 2015 Page 6 This document and any attachments thereto may contain information that is confidential, commercially- sensitive, proprietary, and/or public power utility competitive and financial information in accordance with the provisions of Texas Government Code, Section 552.101, 552.104, 552.110 and/or 552.133, and may be protected from required public disclosure. Memorandum (cont’d) Table 4: Green Valley Energy Center Sound Levels with Attenuated Inlets and Stacks Time Period Measurement Point Measured L90 Attenuated Modeled Facility Expected New Sound Levels Increase Over Ambient (dBA) (dBA) (dBA) (dBA) 11:00 AM - 1:00 PM Res1 42.5 40.4 44.6 2.1 Res2 42.5 41.5 45.0 2.5 Res3 42.5 41.5 45.0 2.5 Res4 42.5 42.6 45.6 3.1 Res5 42.5 42.8 45.7 3.2 Res6 42.5 48.3 49.3 6.8 Res7 40.7 52.2 52.5 11.8 Res8 38.9 55.9 56.0 17.1 Res9 38.9 51.1 51.4 12.5 Res10 38.9 47.9 48.4 9.5 Res11 38.9 47.4 48.0 9.1 Res12 38.9 46.3 47.0 8.1 Res13 38.9 45.5 46.4 7.5 Res14 38.9 45.7 46.5 7.6 5:00 PM - 7:00 PM Res1 47.1 40.4 47.9 0.8 Res2 47.1 41.5 48.2 1.1 Res3 47.1 41.5 48.2 1.1 Res4 47.1 42.6 48.4 1.3 Res5 47.1 42.8 48.5 1.4 Res6 47.1 48.3 50.8 3.7 Res7 46.9 52.2 53.3 6.4 Res8 46.7 55.9 56.4 9.7 Res9 46.7 51.1 52.4 5.7 Res10 46.7 47.9 50.4 3.7 Res11 46.7 47.4 50.1 3.4 Res12 46.7 46.3 49.5 2.8 Res13 46.7 45.5 49.2 2.5 Res14 46.7 45.7 49.2 2.5 December 14, 2015 Page 7 This document and any attachments thereto may contain information that is confidential, commercially- sensitive, proprietary, and/or public power utility competitive and financial information in accordance with the provisions of Texas Government Code, Section 552.101, 552.104, 552.110 and/or 552.133, and may be protected from required public disclosure. Memorandum (cont’d) Time Period Measurement Point Measured L90 Attenuated Modeled Facility Expected New Sound Levels Increase Over Ambient (dBA) (dBA) (dBA) (dBA) 11:00 PM - 1:00 AM Res1 45.2 40.4 46.4 1.2 Res2 45.2 41.5 46.7 1.5 Res3 45.2 41.5 46.7 1.5 Res4 45.2 42.6 47.1 1.9 Res5 45.2 42.8 47.2 2.0 Res6 45.2 48.3 50.0 4.8 Res7 45.3 52.2 53.0 7.7 Res8 45.3 55.9 56.3 11.0 Res9 45.3 51.1 52.1 6.8 Res10 45.3 47.9 49.8 4.5 Res11 45.3 47.4 49.5 4.2 Res12 45.3 46.3 48.8 3.5 Res13 45.3 45.5 48.4 3.1 Res14 45.3 45.7 48.5 3.2 5:00 AM - 7:00 AM Res1 50.4 40.4 50.8 0.4 Res2 50.4 41.5 50.9 0.5 Res3 50.4 41.5 50.9 0.5 Res4 50.4 42.6 51.1 0.7 Res5 50.4 42.8 51.1 0.7 Res6 50.4 48.3 52.5 2.1 Res7 47.4 52.2 53.4 6.1 Res8 44.3 55.9 56.2 11.9 Res9 44.3 51.1 51.9 7.6 Res10 44.3 47.9 49.5 5.2 Res11 44.3 47.4 49.1 4.8 Res12 44.3 46.3 48.4 4.1 Res13 44.3 45.5 48.0 3.7 Res14 44.3 45.7 48.1 3.8 The attenuated sound levels are much lower than those of the un-attenuated model, with a maximum increase of 11.6 dB for the Denton Energy Center and a maximum of 17.1 dB for the Green Valley Energy Center. Sound level contours, shown in 5-dB increments for each facility, are shown in Attachment B. The sound levels shown are for the facilities only using the 35 dB silencers for the intake vents and the exhaust stacks. Further attenuation may be possible, but the feasibility and potential cost was not included within this noise analysis. TEF December 14, 2015 Page 8 This document and any attachments thereto may contain information that is confidential, commercially- sensitive, proprietary, and/or public power utility competitive and financial information in accordance with the provisions of Texas Government Code, Section 552.101, 552.104, 552.110 and/or 552.133, and may be protected from required public disclosure. Memorandum (cont’d) Enclosure Attachment A: Modeling Layouts Attachment B: Sound Level Contours cc: Rob Everard, Burns & McDonnell ATTACHMENT A: MODELING LAYOUTS COPYRIGHT © 2015 BURNS & McDONNELL ENGINEERING COMPANY, INC. Issued: 12/14/2015 Path: Z:\Clients\ESP\DentonTX\85894_RecipProject\Studies\Permitting\Site 1\GIS\DataFiles\ArcDocs\Noise Modeling Results DEC_Layout.mxd tfuller 12/14/2015 Service Layer Credits: Source: Esri, DigitalGlobe, GeoEye, Earthstar Geographics, CNES/Airbus DS, USDA, USGS, AEX, Getmapping, Aerogrid, IGN, IGP, swisstopo, and the GIS User Community NORTH5000500250 Scale in Feet Noise Modeling LayoutDenton Energy CenterDenton Municipal ElectricDenton, Texas Jim Christal Rd Legend Point Sources Vert Area Source Line Sources Area Source Structures Fenceline This document and any attachments thereto may contain information that is confidential, commercially-sensitive, proprietary, and/or public power utility competitive and financial information inaccordance with the provisions of Texas Government Code, Section 552.101, 552.104, 552.110 and/or 552.133,and may be protected from required public disclosure. Service Layer Credits: Source: Esri, DigitalGlobe, GeoEye, Earthstar Geographics, CNES/Airbus DS, USDA, USGS, AEX, Getmapping, Aerogrid, IGN, IGP, swisstopo, and the GIS User CommunityCOPYRIGHT © 2015 BURNS & McDONNELL ENGINEERING COMPANY, INC.Source: Esri, DigitalGlobe, GeoEye, i-cubed, USDA, USGS, AEX, and the GIS User Community, and Burns & McDonnell Engineering Company, Inc. Issued: 11/27/2015Path: Z:\Clients\ESP\DentonTX\85894_RecipProject\Studies\Permitting\Site 1\GIS\DataFiles\ArcDocs\GVEC_11-19-2015.mxd tfuller 11/27/2015NORTH120012060 Scale in Feet Noise Modeling LayoutGreen Valley Energy CenterDenton Municipal ElectricDenton, Texas This document and any attachments thereto may contain information that is confidential, commercially-sensitive,proprietary, and/or public power utility competitive and financial information in accordance with the provisions ofTexas Government Code, Section 552.101, 552.104, 552.110 and/or 552.133, and may be protected from required public disclosure. Legend Point Source Vertical Area Source Line Source Fenceline Area Source Building ATTACHMENT B: SOUND LEVEL CONTOURS COPYRIGHT © 2015 BURNS & McDONNELL ENGINEERING COMPANY, INC. Issued: 12/14/2015 Path: Z:\Clients\ESP\DentonTX\85894_RecipProject\Studies\Permitting\Site 1\GIS\DataFiles\ArcDocs\Noise Modeling Results DEC_Layout.mxd tfuller 12/14/2015 Service Layer Credits: Source: Esri, DigitalGlobe, GeoEye, Earthstar Geographics, CNES/Airbus DS, USDA, USGS, AEX, Getmapping, Aerogrid, IGN, IGP, swisstopo, and the GIS User Community NORTH 800 0 800400 Scale in Feet Sound Level ContoursDenton Energy CenterDenton Municipal ElectricDenton, Texas Jim Christal Rd Hi ckor y Creek50 55 45 60657075 40 45 4545 40 MP4 MP3 MP2 MP1 Res8Res7Res5 Res6 Res4 Res3 Res1 Res2 Legend Point Sources Receiver Vert Area Source Line Sources Area Source Structures Fenceline This document and any attachments thereto may contain information that is confidential, commercially-sensitive, proprietary, and/or public power utility competitive and financial information in accordance with the provisions of Texas Government Code, Section 552.101, 552.104, 552.110 and/or 552.133, and may be protected from required public disclosure. COPYRIGHT © 2015 BURNS & McDONNELL ENGINEERING COMPANY, INC. Issued: 12/14/2015 Path: Z:\Clients\ESP\DentonTX\85894_RecipProject\Studies\Permitting\Site 1\GIS\DataFiles\ArcDocs\GVEC_11-19-2015_CONTOURS.mxd tfuller 12/14/2015 Service Layer Credits: Source: Esri, DigitalGlobe, GeoEye, Earthstar Geographics, CNES/Airbus DS, USDA, USGS, AEX, Getmapping, Aerogrid, IGN, IGP, swisstopo, and the GIS User Community NORTH 1,800 0 1,800900 Scale in Feet Noise ContoursGreen Valley Energy Center Denton Municipal ElectricDenton, Texas 45 40 35 50 30 55 60 40 30 30 35 35 35 30 30 65 MP5 MP4 MP2 MP1 MP3 Res9 Res8 Res7 Res6 Res5 Res4 Res3 Res2Res1 Res14 Res11 Res13Res12 Res10 Legend Point Source Receiver Vertical Area Source Line Source Area Source Structures Fenceline This document and any attachments thereto may contain information that is confidential, commercially-sensitive, proprietary, and/or public power utility competitive and financial information in accordance with the provisions of Texas Government Code, Section 552.101, 552.104, 552.110 and/or 552.133, and may be protected from required public disclosure. ATTACHMENT B MODLEING LAYOUT COPYRIGHT © 2016 BURNS & McDONNELL ENGINEERING COMPANY, INC. Issued: 1/8/2016 Path: Z:\Clients\ESP\DentonTX\85894_RecipProject\Studies\Permitting\Site 1\GIS\DataFiles\ArcDocs\Noise_DEC 6 Eng\Receivers DEC_Layout_1-8-16_Low.mxd tfuller 1/8/2016 Service Layer Credits: Source: Esri, DigitalGlobe, GeoEye, Earthstar Geographics, CNES/Airbus DS, USDA, USGS, AEX, Getmapping, Aerogrid, IGN, IGP, swisstopo, and the GIS User Community NORTH8000800400 Scale in Feet Figure B-1Nearest ReceiversDenton Energy CenterDenton Municipal ElectricDenton, Texas Jim Christal Rd Hi ckor y CreekMP4 MP3 MP2 MP1 Res8Res7Res5 Res6 Res4 Res3 Res1 Res2 Legend Receiver Fenceline This document and any attachments thereto may contain information that is confidential, commercially-sensitive, proprietary, and/or public power utility competitive and financial information in accordance with the provisions of Texas Government Code, Section 552.101, 552.104, 552.110 and/or 552.133, and may be protected from required public disclosure. Service Layer Credits: Source: Esri, DigitalGlobe, GeoEye, Earthstar Geographics, CNES/Airbus DS, USDA, USGS, AEX, Getmapping, Aerogrid, IGN, IGP, swisstopo, and the GIS User CommunityCOPYRIGHT © 2016 BURNS & McDONNELL ENGINEERING COMPANY, INC.Issued: 1/8/2016Path: Z:\Clients\ESP\DentonTX\85894_RecipProject\Studies\Permitting\Site 1\GIS\DataFiles\ArcDocs\Noise_DEC 6 Eng\Noise Modeling Results DEC_Layout_1-8-16.mxd tfuller 1/8/2016Figure B-2Modeling LayoutDenton Energy CenterDenton Municipal ElectricDenton, Texas NORTH 100 0 10050 Scale in Feet Legend Point Sources Vertical Area Source Line Source Area Source Structures