SFPUC 2001 Alameda Watershed Management Plan

III. ENVIRONMENTAL SETTING AND IMPACTSF. AIR QUALITYfollowing construction, and covering stockpiles and trucks hauling soil or other loose materials.In addition, Action roa12 includes BMPs for roadway and trail construction, includingminimizing grading and designing roads and trails to avoid cut-and-fill and to minimizeexcavation. Implementation of Action des9, as described above and in Section IV.F, wouldreduce fugitive dust during project construction to a less than significant level (BAAQMD,1996).The impacts of day-to-day management activities that implement the Management Plan areanalyzed in this EIR and generally would not be subject to further environmental review. Nounavoidable significant program-level air quality impacts related to construction activities havebeen identified in this EIR. However, the San Francisco Planning Department would requireexamination of many specific management actions proposed in the Management Plan at the timethey are proposed for implementation to determine if further environmental review at a moredetailed project-specific and site-specific level were necessary. Table II-1 identifies the specificmanagement actions that are likely to require such study.Changes to Gravel Mining EmissionsGravel mining currently occurs in the Sunol Valley. At present, mining activities in the AlamedaWatershed occur only south of I-680. Fugitive dust emissions from topsoil and overburdenedstripping and transport associated with mining activities at Mission Valley Rock Company andRMC Pacific Materials mining areas are regulated by permits administered by the BAAQMD.Permit limits are designed to keep air pollutant emission levels below BAAQMD’s threshold ofsignificance for PM-10, the primary air pollutant of concern related to mining operations. Dustemissions from mining activities vary from day to day depending on a number of factors, such asprevailing weather and the level and type of mining activity.• As described earlier in this document, actions proposed in the Alameda Watershed ManagementPlan for mining north of I-680 would take place substantially in accordance with limits andmitigations set forth in the conditions of approval for Alameda County’s SMP-32. TheManagement Plan incorporates SMP-32 conditions of approval and proposes modification in thetiming and sequencing of mining (shortening the completion date for water storage pits) andmining reclamation. These modifications may require amendment of the existing permit butwould not bring about any new air quality impacts beyond those disclosed and mitigated in theEIR prepared for SMP-32. Alameda County’s conditions of approval for SMP-32 includemeasures to reduce dust emissions and requirements to maintain all quarry-operated equipmentto reduce exhaust emissions. These conditions reduce air quality impacts from mining to a lessthan significant level. Amendment of the existing permit, if required, would be subject toproject-level environmental review by Alameda County.Mining north of I-680 proposed under the Sunol Valley Resource Management Plan Element wouldreplace a portion of the current mining area south of I-680. Because mining south of I-680 isongoing at a rate based on plant capacity and market demand, increasing the mined area by miningNOP 96.223E: Alameda Watershed Management Plan III.F-14 ESA / 930385January 2001