A Bronx-based emergency food program marked its 30th anniversary today, with residents, volunteers and politicians commemorating the occasion. Members of the organization, Part of the Solution (POTS), say they are feeding more than 400 people each month. In September, the pantry moved into a new 15,000-square-foot building on Webster Avenue, tripling the size of its community dining room, kitchen and office space. "It's helping the community a lot more," says Vietnam War veteran John Burns. With a revamped facility, clients are now able to walk through the aisles and shop as they would in a regular supermarket. Bronx man fills need for turkeys at food pantry