5.2. SR 08-08-2011 - Laserfiche WebLink

Home Browse Search

Table 24-1: Decibel Levels of Common Noise Sources ' - .-. 140 Jet Engine (at 25 meters) 130 Jet Aircraft (at 100 meters) 120 Rock and Roll Concert ' 110 Pneumatic Chipper 100 Jointer/Planer 90 Chainsaw 80 Heavy Truck Traffic ' 70 Business Office 60 Conversational Speech 50 Library ' 40 Bedroom 30 Secluded Woods 20 Whisper ' SOURCE: "A Guide to Noise Control in Minnesota" Minnesota Pollution Control Agency (2008) Along with the volume of traffic and other factors (i.e. topography of the area and vehicle speed) that contribute to the loudness of traffic noise, the distance of a receptor from a sound's source is also an important factor. Sound levels decrease as distance from a source increases. The following rule of thumb regarding sound decreases due to distance is commonly used: Beyond approximately 50 feet, each time the distance between a line source (such as a road) and a receptor is doubled, sound levels decrease by three decibels over hard ground, such as pavement or water, and by 4.5 decibels over vegetated areas. Noise standards vary based on the intended use of the impacted property. The State noise standards are shown in Table 24-2. Table 24-2: MPCA State Noise Standards - Residential NAC-1 65 60 55 50 Commercial NAC-2 70 65 70 65 Industrial NAC-3 80 75 80 75 The existing and planned land uses within the project area are a mixture of , residential, commercial and industrial land. As the standards for residential properties (NAC-1) are the most stringent, this analysis will primarily consider the ' impacts of the development scenarios on existing residential properties in the area. This analysis also considers only daytime noise impacts. Sound Levels City of Elk River Draft Alternative Urban Areawide Review July 2011 Page 76 of 84