Chicago is rated as one of the best TASTING municipal tap waters in the country. That said, you are unlikely to catch anything from it. The quality of the water itself in Chicago is excellent. However, the problems come with the aging lead pipe systems that run miles in the City. 

Unfortunately lead is often found and even if it's usually below regulated levels there is no safe level for children. Chicago has more lead pipe still than any major US City (2021 - artcle). Therefore it's recommended to use an affordable faucet filter certified for lead removal. Running your tap water for 30 seconds will dramatically decrease the amount of lead consumed.

Current City of Chicago Water Reports can be found: here