Ordinance No. 20413 - Laserfiche WebLink

Home Browse Search

Daly-Standlee begins its analysis of potential noise impact by stating that certain areas within the impact area may be subjected to mining activity noise above the limit allowed by the DEQ for a "new noise source" on a "previously unused site." DEQ noise limits for a new noise source on a previously unused site (OAR 340-35-0015(14) and 340-35-0035(1)(b)(B)(i) (Table 8)) are more restrictive than the noise limits for "existing noise sources" (OAR 340-35-0015(17) and 340-35- 0035(1)(a) (Table 7)). Daly-Standlee states that historically DEQ has ruled that when a mine site is expanded onto contiguous property, noise criteria which applied to the equipment before expansion shall also apply to the equipment while in the expansion area. Because aggregate mining has been occurring on the 474 adjacent acres of Delta Sand and Gravel COITlpany ownership since 1927, it could be argued that the existing mining operation is an "existing noise source" and that the expansion area should be subj ected to the less stringent existing noise source criteria under that historic DEQ interpretation. However, it could also be argued that the proposed expansion area is an "unused site" and that equipment moved to that area should be considered a "new noise source on a previously unused site." The city finds that the latter interpretation is the correct one. Delta Sand and Gravel Company has elected to address potential noise impacts of a new noise source on a previously unused site and to subject its future aggregate extractions to the more restrictive DEQ noise limits for such a noise source. Because Daly-Standlee states that certain areas within the impact area may be subjected to mining activity noise above the limit allowed by the DEQ for a new noise source on a previously unused site, this application must demonstrate that the potential noise impacts can be minimized. OAR 660-023-0 180( 1 )(g) provides that noise conflicts are considered minimized under the rule when the relevant DEQ noise regulations (OAR 340-035-0035) are met. Daly-Standlee proposes a variety of administrative mitigation measures (as compared to structural or engineered solutions that do not require constant monitoring), starting with limiting the first and second lift mining operations to the time period from 7 0' clock AM to 10 0' clock PM. Daly-Standlee proposes alternative mining procedures at various locations of the proposed expansion area. Those alternative procedures are provided in Tables 7 and 8 of the noise study. The study further concludes that if the proposed alternative procedures are followed during the first and second lifts then no noise mitigation will be required for the third and subsequent lifts. That statement is based upon the fact that due to the depth of operating equipment below grade (surface level), the noise barrier effect provided by the face of the excavation combined with the distance effect will reduce noise to a level in compliance with the DEQ noise restrictions at all locations within the impact area. Daly-Standlee also recommend restricted use of certain types of heavy equipment in zones proximate to residential property, and additional noise attenuating equip met on some equipment to meet DEQ standards. Opponents of the application, primarily through testimony of Arthur Noxon, PE, acoustic engineer, have challenged the Daly-Standlee report on grounds of methodology and conclusions. (See Exhibits 33e,37, 64, 65, 264, and 278). The city council is compelled by opposition's comments pertaining to the following issues: 1. Ambient noise levels in residential areas were not measured from the more sheltered, quieter private outdoor spaces that may be most impacted by the expanded quarry. Therefore, ambient noise levels used in the noise analysis were higher than true ambient noise levels in some residential locations, and truck noise in residential streets not fully measured. Therefore, noise conflicts were not fully predicted, and minimization of those conflicts is not assured. Exhibit A to Ordinance 20413 - 18