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 contact the Water and Electric Department at 847-716-3558, and staff will check water service records for your residence.