Increased attention is being paid to Tetra Tech’s alleged botched cleanup of hazardous grounds in Hunters Point — especially after Tuesday when Bayview District residents filed a class-action lawsuit for $27 billion...Tetra Tech was contracted to clean up a former U.S. Navy shipyard that the Environmental Protection Agency declared it Superfund site in 1989.  But the EPA found that 97 percent of soil samples in one section and 90 percent of another section didn’t look right, which the company denies...[A]t least 149 plaintiffs have joined the lawsuit to seek $27 billion in damages...