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this mitigation is infeasible and is unacceptable from a design and neighborhood impact standpoint. The City Council evaluated the requirement to achieve the General Plan noise standards with this development at its public hearing and Councilmember Sullivan requested that an addendum to the noise analysis for train horns be completed for the interior spaces of each of the proposed homes. The addendum is part of Exhibit L. It analyzed the noise levels for Lot 1, Lot 6, Lot 7, and Lot 8. As shown on "Table 1: Train Horn Interior Maximum Noise Levels, dBA" of the noise addendum, the operation of train horns will generate from 89 dBA to 112 dBA at a 75- foot distance from the train; that STC 46 rated doors/windows will reduce interior noise levels by 41 dB for Lot 6, Lot 7, and Lot 8, the lots adjoining the railroad right-of-way; and that STC 28 rated doors/windows will reduce the interior noise levels by 20 dB for Lot 1 facing Stanley Boulevard. Table 2, below, copies a portion of the table in the noise addendum and shows the interior noise levels for train horns. Table 2: Interior Noise Levels Due to Train Horns/Whistles Lot Window STC Noise Interior Sound Level Interior Sound Level Rating Reduction (Master Bedroom) (Bedroom Two) 1 28 20 dBA 41 dBA to 64 dBA 52 dBA to 75 dBA 6 46 _ 41 dBA 44 dBA to 67 dBA 51 dBA to 74 dBA_ 7 46 41 dBA 41 dBA to 64 dBA 45 dBA to 68 dBA _ 8 46 41 dBA 41 dBA to 64 dBA 51 dBA to 74 dBA J The train horn sound levels of the Lot 1 Bedroom Two interior is louder than for Lot 6, Lot 7, and Lot 8 because the STC rating of the Lot 1 windows does not need to be as high in order to mitigate the train engine/wheel noise. Train horns are operated to warn motorists and pedestrians of an oncoming train and generate very loud noise levels lasting a short duration; for this reason, train horns cannot be effectively mitigated by residential developments. The only effective mitigation would be if the Union Pacific Railroad and Ace Train were to not use their horns. The use of warming horns is regulated by the Federal Railroad Administration (FRA) of the Department of Transportation (DOT), which supersedes the City's authority. The Planning Commission may wish to discuss requiring up to STC-46 rated doors and windows for all of the proposed homes within this development in order to further mitigate train horn noise. The applicant, however, does not concur with this requirement due to the costs associated with producing STC-46 windows, their appearance, and the potential conflict of such a requirement with the window design requirement that the applicant has accepted. Vibration As required by the General Plan, the noise study includes an analysis of railroad- induced ground vibration. The General Plan requires that the project demonstrate that it would be compatible with the vibration impact criteria established by the Federal Transit Administration (FTA). The study indicates that the homes on Lot 6, Lot 7, and Lot 8 will need to have spread foundation footings or post/beam foundations, resulting in a raised Item 6.a., PUD-82 Page 18 of 22 July 13, 2011