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<br />6.2A <br />Page 22 <br /> <br />Stee1head are present in Cordilleras Creek. Steelhead could be affected by construction <br />discharges of water, including discharges during hydrostatic testing and during dewatering of the <br />pipeline trench, shaft, and tunnel. Infrequent and unplanned summer releases of relatively cold <br />pipeline water to Cordilleras Creek, particularly during summer low-flow conditions, could <br />result localized adverse effects to juvenile steelhead from thermal shock, including mortality. <br /> <br />. Mitigation Measure BID 6: Discharge maintenance release measures <br /> <br />Impact BIO -7: Impacts on mission blue butterfly. <br /> <br />Larval-host plants for mission blue butterfly are found in a small area near the western end of the <br />proposed alignment, at Crestview Drive. Although field surveys did not find primary nectar- <br />plant species for this subspecies near the larval-host plants, this does not mean that Dlission blue <br />butterflies are not or could not be present. Because Project excavations and pipeline construction <br />could disturb the entire right of way, the proposed Project could result in potentially significant <br />impacts on these larval-host plants, mission blue butterfly individuals, or their larvae. <br /> <br />. Mitigation Measure BID 7a: Construction fencing; plan access routes; avoidance <br />measures <br />. Mitigation Measure BID 7b: Habitat compensation <br /> <br />Impact BIO -8: Impacts on burrowing owl. <br /> <br />Although burrowing owls were not detected within the study area during the 2005 surveys, <br />suitable habitat for the burrowing owl was found between the Newark Valve Lot and the Mission <br />Boulevard Service Connection. Burrowing mammals (e.g., ground squirrels) throughout the <br />eastern segment of the Project area provide suitable nesting habitat for burrowing owl, which <br />could n10ve onto the site to nest prior to grading. Disturbing these owls, if present during the <br />nesting season (February 1 through August 31)t could potentially result in significant impacts, <br />such as nest abandonment and mortality of young. PG&E's installation of the fiber optic cable <br />between the Ames and Ravenswood Substations could also result in impacts on burrowing owl. <br /> <br />. Mitigation Measure BID 8a: Conduct burrowing owl surveys, <br />. Mitigation Measure BID 8b: Mapping; monitoring; buffer zone adjustments; passive <br />relocation measures <br />. Mitigation Measure BID 8e: Avoidance measures <br /> <br />Impact BIO -9: lmpacts to saltmarsh common yellowthroat and tricolored blackbird. <br /> <br />Marginally suitable habitat for saltmarsh common yellowthroat and tricolored blackbird, which <br />are both State species of special concern, is found adjacent to the proposed tunnel shaft location <br />....... .()J:l.th,~..~~~,-,~~'y ~1.Y.~~9.t"l1<J. .~t~h.~ .Rc.tY~~s.~9.()gsi~~.. ..:P()t.~J:l~~J.l.y...~.ig~jfi~.~J:l.tJrl~p.~9.~S...9.c>.~J4... ... ...... .... <br />. .result fromconstruction;.related activities during the nesting season. (February. 1 through. August. <br />31) that could cause these birds to abandon occupied nests. However, Project construction would <br />not result in a permanent loss of suitable habitat for saltmarsh common yellowthroat or tricolored <br />blackbird. <br /> <br />. Mitigation Measure BID 9a: Site nlonitoring and surveys <br />. Mitigation Measure BID 9b: Handcut cattails to ground level and haul away the <br />vegetation <br />. Mitigation Measure BID 9c: Restrict grading and construction activities <br /> <br />Impact BIO -10: Impacts on saltmarsh wandering shrew. <br /> <br />12 <br />