One burger joint in Pittsburgh has repeatedly kept raw hamburger meat, lettuce and coleslaw at temperatures that allow bacteria to flourish. A chain restaurant’s worst violations in the past three years were a missing floor tile and a dirty floor drain. Both restaurants have maintained their approved-to-operate green stickers from the Allegheny County Health Department, but one would’ve earned a ‘C’ and the other an ‘A’ if the county’s attempts to institute a restaurant grading system had passed. Nearly all of the roughly 4,200 restaurants in the county have a green sticker — no matter whether it had five high-risk health violations in its last inspection or none. There have been two failed attempts, most recently in May, to pass an A-B-C restaurant grading system that could give consumers more refined health information at a key decision-making point — entering a restaurant. Although the Allegheny County Health Department supported the change, the county council voted the A-B-C system