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Home My WebLink About2007-01-12 Skanska Ltr to OPHSKANSKA 316007 January 12, 2007 Mr. Eric Johnson City of Oak Park Heights P.O. Box 2007 Oak Park Heights, MN 55082 Dear Eric: Sincerely, Skanska USA Building Inc. Dan Bu Project Manager cc: Central File 1 Field k Reference: Loge's of Oak Park Heights, MN As the City has requested, a noise survey has been conducted at the recently constructed Lowe's Home Improvement store to measure the noise level created by the generator and trash compactor located at this site. Attached with this letter is the report dated January 8, 2007, prepared by Terracon, a local independent testing agency. Minnesota Pollution Control Agency Noise Pollution Control Standards were used in determining acceptable levels of compliance. The results of the sound testing found that the trash compactor is in full compliance with MPCA standards. However, the Generator exceeded noise standards at one monitoring point (east property line). Lowe's is currently pursuing options to reduce the noise levels to be within the MPCA guidelines. One of the options proposed by the generator manufacturer is a Level 1 sound housing enclosure, however, the lead time for design, fabrication and installation would be approximately 12 weeks. Several other options are also under consideration that would reduce the noise output. 1 expect Lowe's to finalize a sound reduction plan shortly and will send you an update as soon as this occurs. Feel free to give me a call with any questions or concerns you may have. Skanska USA Building Inc. 5250 Lovers Lane, Suite 200 Portage, MI 49002 Phone 269 342 5400 Fax 269 342 5799 Web www.skanskausa.com January 8 2007 Jared Hawkinson Project Manager Estimator Collin Electrical Construction Co./Convergent Media 278 State Street St, Paul, MN 55107 Re: Letter Report of Noise Survey Lowe's 5888 Nova Scotia Avenue North Oak Park Heights, Minnesota 55082 Terracon Project No. 41067051 Dear Mr. Hawkinson: erracon Project Information Consuiting Engineers 8i Scientists 3535 Hoffman Road East Whde Bear Lake, Mnnscta 5511Ci-5376 Phone 651L77:0,1500 Fax &177Q1657 WAV.temi(;on,com Terracon Consultants, inc (Terracon) has completed a noise survey at the above referenced site. The purpose of this letter is to present the results of the noise survey. Terracon completed a noise survey at the request of Collins Electrical Construction Co,/ Convergent Media for an electrical generator and trash compactor located on the exterior of the Lowe's store in Oak Park Heights, Minnesota. The noise survey was conducted in general accordance with the Minnesota Pollution Control Agency (MPCA) Noise Pollution Control Standards as set forth in Minnesota Rules Chapter 7030 and A Guide to Noise Control in Minnesota issued by the MPCA and dated March 1999 (Noise Control (3uidance). The purpose of the survey was to measure the noise level created by a generator and trash compactor at a property adjacent and east of the site where residential town homes are to be constructed. Noise Survey A Terracon representative conducted a brief survey of the properties adjacent to the site in order to select the most appropriate monitoring [oration. Based on a telephone conversation with Eric Johnson of the City of Oak Park Heights, the monitoring locations were limited to points an the site property itself and not on adjacent properties. The Terracon representative selected two monitoring points on the property line of the site. Point 1 was located near the southwest corner of the property approximately 175 feet west and 35 feet south of the trash compactor. Point 1 was selected for its proximity to the trash compactor and for its distance from a barrier wall that has been erected on the southern property line. Point 2 was located on the eastern property [inc approximately 239 feet east and 59 feet south of the generator. Point 2 was selected for its proximity to the generator and an adjacent property to the east that will eventually support town homes. A sketch of the site and the monitoring points is provided an D ivering Success for Clients arid Employees Since 1965 More Than 80 Offices Nationwide Lowe's/Oak Park Heights, MN Noise Survey Project #41067051 January 8, 2006 the noise survey form attached. According to Minnesota Rues 7030.0050, the site has a Noise Area Classification (NAC) of 2 for retail trade facilities. Sound level measurements were taken using a Quest 1200 sound level meter equipped with a wind screen attachment The sound level meter was set to the “A" weighted scate used for measuring sounds within the range of human hearing and ail measurements were taken using the "FAST" response setting. The sound level meter was mounted on a tripod at a height of approximately 3,5 feet above the ground surface,. Prior to conducting measurements, the sound level meter was calibrated using a calibration attachment,. The calibration information was recorded on the attached noise survey form. For the background noise level, several measurements were take over a period of 10 minutes and averaged. The background noise level was estimated at approximately 50 decibels (dBA), Generator Monitoring Monitoring of the generator noise level was conducted for one hour monitoring points 1 and 2 from 1:30 pm to 3:30 pm. A sound level reading was made every 10 seconds during the hour for a total of 360 readings for each monitoring point. The sound levels were recorded on the manual monitoring data sheet attached. A light breeze of approximately three to five mites per hour was observed from the north and the temperature was approximately 45°F. Using the method described in the Noise Control Guidance, the 10 and 50 percentile noise levels (L10 and L50, respectively) were estimated using the results recorded on the attached manual monitoring data sheets. The L10 and L50 for the generator at monitoring points and the noise standard for the NAC are listed below in Table 1. Table. 1 — Generator Noise Location Monitoring Point 1 Monitoring Point 2 57 L50 (dBA1 56 • • 73 73 Noise Standard for NAC , i 1 10 65 70 Trash Co pactor Monitoring The trash compactor was not monitored in the same manner as the generator because it did not operate continuously. Terracon conducted measurements at monitoring points 1 and 2 while the trash compactor was operated once by itself and once while the generator was in operation, in each case, the compactor operated for approximately one minute, which allowed N':',Pro:41 067051 '1,8tler rePNT.ox 2 Iferracon Lowe's / Oak Park Heights, MN Noise Survey Project #41067051 January 8 2006 for six measurements. No change in sound level was observed at the monitoring points while the trash compactor was operated at the same time as the generator; therefore the measurements were not recorded. Table 2 below lists the measurements made white only the trash compactor operated. Because the sound level measurements varied by less than one dB during the compactor operation cycle at each monitoring point, only one measurement value is listed. The sound levels measured are shown an the attached manual monitoring sheet, Table 2 — Trash Compactor Noise Location . • • - • • • • • • - • • • • • • • Monitoring Point 1 Monitoring Point 2 Sound Leve 54 52 Conclusions The L10 and L50 values from Table 1 and the measurements from Table 2 were compared to the noise standards in Minnesota Rules 7030,0040 for NAC 2. The measurements for the trash compactor at points 1 and 2 listed in Table 2 did not exceed either the L10 or the L50 standard. The L10 and L50 values estimated for the generator at point 1 did not exceed the NAC 2 standards; however, both the L10 and L50 values estimated for the generator at point 2 exceeded the NAC 2 standards (See Table 1), Minnesota Rule 7030,0030 states that exceedances of noise standards for an NAC may not be violated upon establishment of land use within the NAC. Based on the noise standard exceedances observed at point 2 during operation of the generator, noise abatement measures may be necessary depending on the application of noise standards by the local municipal authority, The City of Oak Park Heights should be consulted to determine it noise abatement measures should be implemented, Sincerely, TERRACON JJSn Unkefer, P.G. Environmental Scientist JU/DJWfdw r1": \Pm Act- / 067 51 repo r3 d 3 David J. Wolfgrafri, Senior Engineer lrerracon • Atoet, w VESTIGATO INSTRUMENTATION: LSD 400 SIN PO r IMO SOURCE: 6e44.4-4- MONITOR LOCATION: - ' .....,..; \ t Tt A kitc ,r,- t. !....., ,x, . ¶L , ...... • ,,, 1.,.. .<:..t -t. I, Q i ' \ • • • • • • -............,,,,,,,,..------.,-,,,,,„.,,,„,..-„,„„----------,..„..., X II 1 Ak. Or I 1 '1,5 BC;Itt-i:'5•-r' ) 0 .A. • 0 70 MO O 'r) NOISE SLTRVEY • DATE: 1; TIME START: J30, TIME END: _,(510._ DIAGRAM 4 L'[( ATE - Nt hI SO 1R1 NOISE RECEIVER-, MICROPHONE LOGVIION, I— .FCIING 013.11a7TSIOBSTRUCTIONS AND DISTANCES) G eAtctivc , ht . . ......... . . . . , , . • . . . . •• • Meteorological Conditions Wind S peed / Direction mph/ TEMPERATURE: CALEBRAT ON CALIBRATOR SERIAL NUMBER:V ?,TALIBRATION FREQUENCY: CO) Hz INITIAL: (4.1 FINAL: 4 0 RI ,TS: LI 0 dB A 1,50 daA ES 1 1 .-- 16