SFPUC 2001 Alameda Watershed Management Plan

III. ENVIRONMENTAL SETTING AND IMPACTSD. HYDROLOGY AND WATER QUALITYveg1 requires preparation and implementation of a Vegetation Management Plan. Action veg7requires that operations and maintenance activities comply with erosion-control bestmanagement practices. Actions veg8 and veg9 identify areas subject to slope instability and soilerosion and require implementing erosion-control measures. Action veg10 establishes long-termerosion and sediment control monitoring. Action veg11 calls for developing and implementingan Integrated Pest Management program for the Watershed. Action veg13 minimizes thedisturbance of serpentine soils to prevent release of asbestos fibers to the water supply.Aquatic Zone Protection Actions aqu2 through aqu8 provide guidance for operations andmaintenance activities associated with the protection of reservoir shorelines and streambanks,which relates directly to protecting water quality. Actions aqu10, aqu11, aqu12, aqu13, andaqu14 specify management of sedimentation basins or sediment detention basins to optimizetheir use in maintaining water quality. Action fis6 calls for adoption of nontoxic managementpractices for protection of aquatic resources. Action sta6 provides water quality training forSFPUC staff. Action fic2 authorizes or prohibits specific lease or permit activities, partiallybased on impacts to water quality. Action inf3 calls for recording and updating water qualitydata to establish a database for overall water quality management.On a program level, implementation of the policies and management actions described above, andas described in Section IV.D, would reduce potential water quality impacts related to Watershedoperations and maintenance activities to a less than significant level. However, the San FranciscoPlanning Department would require examination of many specific management actions proposed inthe Management Plan at the time they are proposed for implementation to determine if furtherenvironmental review at a more detailed project-specific and site-specific level were necessary.Table II-1 identifies the specific management actions that are likely to require such study.Changes to Gravel Mining OperationsThe Management Plan would allow continuation of mining activities in the Sunol Valley(Policy WA37) as well as consideration of amending the existing mining permits to expandmining south of I-680, either in depth or in both depth and area, or modifications in the timingand sequence of mining and mining reclamation north of I-680 (Actions sun1, sun2a/2b). Asdescribed previously under Setting, Section 1.6, Gravel Mining, mining operations havehistorically affected hydrologic and water quality conditions in the Sunol Valley. These impactsare currently being addressed through conditions of approval for the operating permits and leaserequirements for SMP-32, SMP-30, and SMP-24. However, implementation of Actions sun1 andsun2a/2b could result in modifications of existing mining permits that could result in potentiallysignificant effects on water quality and groundwater.•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 butNOP 96.223E: Alameda Watershed Management Plan III.D-27 ESA / 930385January 2001