Lead service lines are generally a dull gray color and are very soft. The service line typically enters your residence near your water meter. Lead service lines can be easily identified by carefully scratching them with a key or coin. If the pipe is made of lead, the area you’ve scratched will turn a bright silver color.
A certified plumber can tell you for sure if you have a lead service line, check for lead solders in your internal pipes and look for fixtures containing lead. You may also check the service line material inventory listing published by the Water & Electric Department. In accordance with 415 ILCS 5/17.12, the utility is required to publish an inventory of water service materials on the distribution system which is updated on a yearly basis. Address-level information on water services may be found here.