MediaNews reporter Shirley Dang takes a look at progressive restaurants' turn away from the Pellegrino bottle, pretty much sidestepping an obvious question: Why do restaurant diners shun plain, unfiltered tap water in the first place? Dang echoes a similar piece two weeks ago in the San Francisco Chronicle. Dang lays out the premise: "This spring, Chez Panisse in Berkeley will join the small cluster of Bay Area restaurants like Incanto, Nopa in San Francisco, and Poggio in Sausalito that have completely traded in bottles for tap. Shipping glass bottles of European spring water across the Atlantic to American restaurants pollutes the air and oceans, environmentalists say." Okay, cool. Chez Panisse is taking its lead from Incanto proprietor Mark Pastore, an early adopter. Dang again: "Pastore spent $6,000 on his water system. Every three or four months, he replaces the four filters, meaning he shells out at least $750 a year on filters alone. 'Water is a profit center for most restaurants,' Pastore said, standing next to the chromed German beer tap that he installed to dispense the in-house flat and sparkling water. 'For us, it's a cost center.'" What Dang doesn't quite around to is probing diners' desire for anything other than tap in the first place. Are we all just victims of thirty years of ad pitches, starting with Perrier and ending with Dasani? "A bottle of bubbly - whether Gerolstein from Germany or Evian from the Alps - lends special cache to a meal," suggests Dang. She quotes Marcus Hernandez, general manager at Postino in Lafayette: "When people go out, it's to get things they usually don't get." Sounds like a story with deeper roots: Is the turn away from the tap the result of a long marketing campaign, or a vote of no confidence in our basic infrastructure?