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<br />Memo <br /> <br /> <br />PAZC Qt::... -~ L Z; ) <br />ORC MJd-3 ~ <br />Oate--.Ll- 1- () 0 <br />Exhibit No. ~ <br /> <br />I <br />j <br />ENGINEERS 'j <br />MN. : ~~~ <br /> <br />................."..........~..~........~....=..~............. \\~~~.j <br />-_"~M"'~~""W"_W'~::~~::"'~" :.~.~:::~j <br /> <br />Daly · Standlee & Associates~ Inc. <br /> <br />Date: <br /> <br />October 27, 2006 <br /> <br />4900 s.\~. Griffith Drive <br />Suite 216 <br />Beaverton. Oregon 97005 <br />(503) 646-4420 <br />Fo>: (503) 646.3385 <br /> <br />\ <br />\ <br />\. <br />.\ <br /> <br />To: Mr. George Staples <br />Risk Manager <br /> <br />From: <br /> <br />Delta Sand & Gravel <br />999 Division Avenue <br />Eugene, Oregon 97404 <br /> <br />Kerrie G. Standlee, P.E. <br /> <br />Re: <br /> <br />Delta Sand & Gravel Mining Area Expansion Noise <br /> <br />DSA File #: 137045 <br /> <br />Message: Mr. Staples, <br /> <br />At your request, Daly-Standlee & Associates, Inc. (DSA) conducted additional analyses to <br />determine mitigation measure's that could be used to ensure the noise radiating to residences <br />west of Delta's proposed mine expansion area would be in compliance with the DEQ noise <br />regulations during the time material is excavated in the setback area along the northern, <br />western and southern boundaries of the expansion area to allow for the construction of an <br />aquaclude. This memo documents the results. of the analyses and provides our <br />recommendations based on those results. <br /> <br />As directed by Delta Sand & Gravel, DSA conducted the analyses assuming a 4 foot thick <br />layer of overburden material from the aquaclude trench area would be used to construct a <br />temporary noise reduction berm between the trenching operations and residences located in <br />the vicinity of a particular work area where trenching is occurring. Also, as directed by Delta <br />Sand & Gravel, DSA assumed that a new CAT 980H front-end loader with a noise <br />suppression package would be used to excavate the material from the aquaclude trench. DSA <br />measured the noise generated by Delta Sand & Gravel' s CAT 980G front-end loader during <br />the early stages of the expansion noise study. According to data supplied by CAT, the 980H <br />front-end loader with the noise suppression package is approximately 5 dB quieter than the <br />980G front-end loader. Therefore, the sound data used in the original noise analysis was <br />adjusted by 5 dB and used in this study. <br /> <br />137045-M2.doc <br /> <br />Page I of 3 <br />