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ARROYO LAGO RESIDENTIAL PROJECT ADDENDUM FCS 153 Https://adecinnovations.sharepoint.com/sites/PublicationsSite/Shared Documents/Publications/Client (PN-JN)/2148/21480036/Addendum/21480036 Arroyo Lago Residential Project Addendum.docx and practices. Implementation of MM NOI-1 would ensure that construction noise levels would not result in a substantial temporary increase in ambient noise levels in excess of the FTA’s thresholds for construction noise impacts. Therefore, with implementation of MM NOI-1, consistent with the impact conclusions of the Prior FEIR, temporary construction noise impacts would be reduced to less than significant. Operational Stationary Noise Impacts Operational Traffic Noise Impacts A significant impact would occur if operational noise levels generated by mobile noise sources at the project site would result in a substantial permanent increase in ambient noise levels in excess of the applicable noise standards established in the City’s General Plan. The City’s General Plan Noise Element Program 1.3 states that a significant noise impact would occur if exterior noise increased by more than 4 dBA over ambient levels. Therefore, for the purpose of this analysis, an increase of more than 4 dBA above ambient noise levels that would exist without the proposed project would be considered a substantial permanent increase in ambient noise. According to the Prior FEIR, implementation of the County Project would result in traffic noise levels of up to 59.1 dBA CNEL under existing plus project conditions. However, the measured existing ambient noise levels adjacent to this roadway segment are 59 dBA CNEL.40 Accordingly, project traffic noise levels would result in a 0.1 dBA increase over existing ambient noise levels. The analysis also showed that future plus project traffic noise levels would only result in a 0.6 dBA increase over future traffic noise levels that would exist without the project. Therefore, the proposed project would not result in a substantial increase in traffic noise levels above the City’s adopted threshold. The proposed project would be located on the same site and would include substantially the same residential uses (with slightly fewer units as well as a substantial reduction in off-site utility infrastructure) as compared with the County Project. Further, the proposed project anticipates a slight reduction in traffic noise from what was previously analyzed due to the nominally lower trip generation from the reduction in proposed residential units. As such, consistent with the impact conclusions in the Prior FEIR, the proposed project would not result in a substantial increase in traffic noise levels compared with traffic noise levels existing without the project, and this impact would be less than significant. Mechanical Equipment Operations A significant impact would occur if operational noise levels generated by stationary noise sources at the project site would result in a substantial permanent increase in ambient noise levels in excess of the applicable noise standards established in the City’s General Plan. Program 1.3 of the City’s 40 The 59.5 dBA noise level presented is in a Community Noise Equivalent Level (CNEL), which is weighted by applying a 5 dBA penalty to noise between 7:00 p.m. and 10:00 p.m. and a 10 dBA penalty between 10:00 p.m. and 7:00 a.m. The day/night equivalent noise level only applies a 10 dBA penalty to noise between 10:00 p.m. and 7:00 a.m. Because of this weighting, a noise level that is weighted in a CNEL would always remain higher than the same noise level weighted over a day/night equivalent noise level.