765 ILCS 745/6.2: Utility services.

(a) A park owner is prohibited from requiring a tenant to pay for utility services, such as water, sewer, and trash used in common areas in which a public utility company is charging for those services. If the public utility usage for common areas is not separately measured by equipment such as a water meter, the park owner may not charge the tenants for more than 80% of the public utility services for which the park owner was billed.

(b) On an annual basis, a park owner must provide tenants with a written explanation of how a tenant's share of the utility charge was calculated, and upon request from a tenant, must provide a copy of the park's monthly utility bills to tenants for any utility charge separately billed under this Section.