Ordinance No. 20413 - Laserfiche WebLink

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2. Impulse noises, such as the banging of dump trucks as they unload, were not measured by Daly-Standlee. The aquac1ude will involve filling of a 30-foot deep trench proximate to residences, presumably with associated impulse noises, inside the DEQ setback for mining operations. Therefore, noise conflicts were not fully predicted and minimization of those conflicts is not assured. 3. Because the expansion site has sensitive receptors, such as residences, on three sides, it is likely that excavation activities will not always be shielded by the quarry wall during third and fourth lifts. For instance, the residences on the south side of the expansion site will have a direct line of sight to excavation occurring along the north property line. Berms will be installed only temporarily for the aquaclude construction. The Daly-Standlee analysis does not specifically address whether the distances involved will mitigate the noise impacts. Therefore, noise conflicts were not fully predicted and minimization of those conflicts is not assured. 4. Most of the proposed mitigation measures depend on administrative oversight, such as self-monitoring the distances between certain types of equipment and property lines, hours of operation, frequency of loads, traffic speeds within the expansion area, etc. These are more difficult to monitor and enforce than structural or mechanical solutions, such as the installation of berms that can be inspected and measured. There is no programmatic monitoring system recommended other than DEQ oversight. Therefore, minimization of noise conflicts is not assured. Lane County found that the initial construction of the aquaclude, which involves the removal, stockpiling and return of topsoil and overburden to the trench during the surface digging, constitutes a construction project that is exempt from DEQ noise level requirements and enforcement. The City Council disagrees. Installation of the aquaclude involves mining of aggregate material to a depth of at least 30 feet and sales of most of that material. It is a mining operation by definitions of OAR 660-023-0180 (Mineral and Aggregate Resources), ORS 215.298 (Mining in exclusive farm use zone), and ORS 517.750 (Non Agricultural lands) and should not to be compared with the relatively simple surface preparation of a typical construction site. The noise generated by the excavation and filling of the aquaclude trench is a mining activity and is therefore not exempt from DEQ noise standards pursuant to OAR 340-035- 0035(5)(g). In any case, noise conflicts associated with aquaclude construction have not been adequately minimized to meet adopted standards. Defects in the noise measurements and predictions are cumulative; hence, the total effect of overestimating ambient noise levels, underestimating new noise from mining activities and transporting excavated materials through adj acent neighborhoods, and failure to account for all noise caused by mining to create the aquaclude can result in increases in the perceived noise of over 15 dBA, a possible violation ofDEQ noise regulations. We find that potential noise conflicts from the proposed mining of the expansion area cannot been minimized as required by Goal 5. Dust The applicant's expert, Bridgewater, provides evidence that, with the appropriate dust minimization measures, mining of the proposed expansion area would be compliant with Lane Regional Air Pollution Agency (LRAP A) airborne particulate matter emission standards and fugitive dust requirements. We note that, for those types of conflicts addressed by local state or Exhibit A to Ordinance 20413 - 19