Slow drains or foul odors? It may be time to inspect your interior sewer lines. Mark 4 Plumbing offers full-service interior sewer line inspections, repairs, and replacements. We locate blockages and pipe damage. Serving homes and businesses in Philadelphia, we ensure every sewer line is up to code, safe, and functioning properly. From partial repairs to full replacements, we keep your property clean and your plumbing flowing.