The Pittsburgh Water and Sewer Authority will spend nearly $50 million this year to replace thousands of old lead water lines under a settlement the Pennsylvania Public Utility Commission approved Feb. 7.

The joint settlement between the authority, the PUC’s Bureau of Investigation and Enforcement, the Office of Consumer Advocate, the Office of the Small Business Advocate, and Pittsburgh United—a coalition of faith, labor, and environmental groups—was approved by the commission in a 5-0 vote.

The settlement...