Pittsburgh's basement water problems have a specific history. In 2004 the remnants of Frances and Ivan reached the area within 9 days, and Ivan's rainfall on Sep 17 ranked 1st among the tropical storm events listed for the city. Backups also come from the sewer system itself: PWSA says sewage can back up when a private or public sewer is blocked, broken, or overwhelmed by heavy rain or snowmelt, and that backwater valves, downspout disconnection and trench drains must be considered case by case. That shapes how you hire. Ask any contractor why a given fix suits your house and your sewer line, rather than accepting a standard package. In Allegheny County, plumbing work needs a permit, the Health Department must approve a plumbing plan before work starts, and every permit requires a final inspection. Ask who pulls the permit and who books the inspection. Contractors doing home improvements above the state threshold must also be registered with the Office of Attorney General, so ask for their registration number.