In January, the Pittsburgh Water and Sewer Authority began the daunting task of cataloging the material of its 70,933 service lines to determine how many are made of lead. To date, they've inspected nearly 1,750 lines across the city, and some city residents are beginning to receive their results in the mail.
Block by block, home after home, a crew of three contractors walks slowly, stopping every few feet to plant a small pink flag into the ground. The flags mark the lids to curb boxes, which provide underground access to the service lines carrying water to each home. Since January, when curb box inspections began in earnest, the crew has been seeking the answer to a simple, yet critical question: How many lead service lines are there in Pittsburgh? Though the lead test results released Tuesday by the Pittsburgh Water and Sewer Authority do not exceed the federal action limit, the question must still be answered. For one, the 90th-percentile result of 15 ppb is the threshold.