Item C: Delta Sand and Gravel Metro Plan Amendment

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“Thickness of aggregate layer” is defined above as “the depth of the water-lain deposit of sand, stones, and pebbles of sand-sized fraction or larger, minus the depth of the topsoil and nonaggregate overburden.” The applicants’ report concludes that the average cumulative width of the aggregate layer is 70.5 feet with a maximum overburden of 4 feet. The applicant’s determination of the aggregate deposit width was based on two methodologies: averaging the thickness (width) of the gravelly bearing material (excluding overburden, sand only, and clay) from the three boring logs and pit wall, and extrapolating the boring results to the full expansion area. Exhibit 33 Dr. Reed () questions the applicant’s assertion that the average thickness of the aggregate layer exceeds a 60-foot depth. He contends that the actual depth of quality gravel cannot be accurately ascertained due to mixing of the various layers within each. DOGAMI notes that several operations encounter 10 – 15 foot thick seams of clay, which may be mixed with aggregate and treated as internal waste during Exhibit 144 production (). Dr. Reed notes that the DOGAMI evidence confirms that differences may exist between younger and older (shallower and deeper) resources and that the DOGAMI testimony did not address overall quality of the resource materials or representative testing methods for determining whether ODOT standards are met. Discrepancies in Boring Hole 3’s geologic log data identified by Dr. Reed call into question the thickness of the different layers, such as the thickness of the sand and gravel layers. Dr. Reed’s testimony suggests that if the log of one of the entire three boring holes is erroneous, it calls into question the validity of the other two boring tests as well. Since the logs of the boring holes form the factual basis of the determination of sufficient thickness of the resource, the applicant may not have provided adequate information to support this criterion. Based on the information before them, four Lane County Planning Commissioners and two City of Eugene Planning Commissioners voted that the sampling method for the quality analysis of the aggregate was inadequate to determine significance of the resource pursuant to OAR 660-023-180 (3). Conclusion: The Eugene City Council considered the record established by the Planning Commissions and additional evidence presented during a subsequent public hearing and extended period of open record. A sample of relevant evidence is listed below. A preponderance of evidence regarding the quality of the resource references testing methods and professional standards (Army Corps of Engineers, ASTM, and AASHTO) that may be applied. Both the applicant and opponents essentially relied on the same standards for their arguments, but reached different conclusions. The Eugene City Council concludes that there is insufficient evidence in the record to support a decision that a representative set of samples of aggregate material in the deposit on the site meets the applicable Oregon Department of Transportation (ODOT) specifications for base rock for air degradation, abrasion, and soundness (OAR 660-023-180 (3)(a)) or that the average thickness of the aggregate layer within the mining area exceeds 60 feet in this Lane County site (OAR 660-023-180 (3)(d)(B)(i)). Therefore, the City Council cannot find that the subject site is a “significant aggregate site” pursuant to OAR 660-023-180 (3).