Laserfiche WebLink
agencies. Since then it has been adopted by several agencies including <br />• the Federal Highway Admi nistration (FHIJA), the Department of Housing and <br /> Urban Development (HUD), and the Federal A viation Administration (FAA). <br />' Those agencies have elected an outdoor residential maximum 24-hour Ldn of <br />- 65 dBA. <br />~. <br />Twenty-four hour Ldn's in areas adjacent to SH 133 and Stevens Gulch <br />L_. Road were assessed for the current and proposed Colorado Westmoreland pro- <br />duction levels using the Federal Highway Administration (FHWA) Highway <br />Traffic Noise Prediction Model (Barry and Reagan, 1978). Traffic data used <br />! were derived by International Engineering Company, Inc. Coal truck and <br />~._. <br />__ employee traffic information was provided by Colorado 4estmoreland Inc. <br />_ Table 3 provides a summary of the data used. <br />~_• <br />Estimates were first derived for a distance of 100 feet from each of <br />r <br />the two roads. Results are presented in Table 4. These estimates indicate <br />increased production could cause Ldn noise levels in areas adjacent to roads <br />l <br />.~. to increase by approximately 3 to 4 dBA. <br />One hundred-foot values were adjusted for other distances and 55, 60, <br />r <br />and 65 dBA Ldn noise contours were plotted (see Figures 3 and 4). Since <br />no noise sensitive areas, i. e., residences, farms, etc. are located on the <br />i~ upper portion of Stevens Gulch Road, that area was omitted. <br />r <br />The current production contour map (Figure 3) indicates that eight <br />homes are located within the 60 dBA Ldn contour and four more are encompassed <br />• by the 55 dBA contour, The increased production (1.3-million TPY) contour <br />_ map indicates fifteen homes will be located within the 65 dBA Ldn contour, <br />-19- <br />