Item 6: Ordinance on Delta Sand and Gravel

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Neither the record nor conditions are explicit about whether the berms installed for noise mitigation would be located closer to the residences than the setback specified for the aquaclude. In other words, it is not specified if the 10-foot high earthen berms would be closer than 50 feet to the property lines. If they were, the dust impacts could be even worse. Inasmuch as the draft findings for dust impacts already find that the conflicts are not adequately minimized, and an economic, social, environmental and energy (ESEE) analysis finds no overriding reasons to approve the mining, no significant changes to the findings are needed. Staff Recommendation: Dust: Amend finding to simply recognize that the variance granted by the county would exacerbate the dust impacts even further. Wetlands. Portions of the proposed expansion site’s western boundary follows an old meander scar of the Willamette River, commonly called East Santa Clara waterway. The aquaclude variance would allow construction activities to within 50 – 100 feet of this intermittent waterway, depending on the neighboring zone, as described above. This waterway was added to the City’s and County’s Goal 5 inventories as a “Category D” stream, which requires a setback of 20 feet. Installation of the aquaclude and berms would not encroach into the existing Goal 5 setback. There is no impact that would violate existing local standards. Staff Recommendation: Wetlands: No changes recommended except to clarify the status of the waterway as a Goal 5 resource and the locally adopted setbacks to this waterway. Flooding and Groundwater. The aquaclude is proposed as a mitigation against groundwater depletion and is designed to respond to concerns about too much rise in the groundwater in the neighboring urban areas. Staff finds nothing in the record that would quantify the different impacts between the proposed location for the aquaclude and another location if the variance were not granted. There is testimony in the record that describes how the subsurface water system is very large compared to the relatively small expansion site. Moving the aquaclude 50 – 100 feet to the east would probably not have a significant effect on flooding or groundwater. Staff Recommendation: Flooding and Groundwater: No changes recommended. Visual Impact.Visual impacts are not subject to the Goal 5 criteria for mining, but it is included in this paper for the sake of completeness. Construction of the aquaclude includes a 10 foot tall berm for noise attenuation. It is not clear how long the berm will remain, but for its duration it might be visible from nearby residences. The berm would help block views of construction equipment. Staff Recommendation: Visual Impact: No changes recommended.