A Pacific Gas and Electric project aimed at meeting the demands of an expanding biotech campus in Foster City will begin in the coming weeks and involve boring a tunnel underneath State Route 92. Existing infrastructure cannot meet the needs of Gilead Sciences, a multi-billion dollar international pharmaceutical company that’s continuing to build out its nearly 72-acre campus in Foster City. Now, PG&E plans to install 2,200 feet of a new 8-inch steel gas main along a stretch of southbound Foster City Boulevard leading toward the biotech company’s headquarters.