Champaign County authorizes MS4 notice of intent while awaiting Illinois EPA rule update

Champaign County on March 20 authorized the county executive to sign the notice of intent required for the county’s MS4 stormwater permit covering program years 2024–2029, while county staff said they are awaiting a finalized Illinois EPA ILR40 permit that could impose new monitoring requirements.

John Hall, identified in the meeting as the county MS4 program contact, told the board the MS4 program runs in five‑year cycles tied to the Illinois EPA general permit (ILR40). Hall said the county missed the routine renewal last year and is seeking to re‑establish its notice of intent so the county is aligned before the state issues a revised ILR40.

Why it matters: a draft ILR40 released in 2021 included potential new requirements such as sampling stormwater discharges, which could create significant operational and cost questions for local governments if adopted. County staff said the draft changes may explain the delay in the EPA issuing a final rule.

Discussion highlights:

• Hall summarized that the county’s current program maintains mapping, public education, illicit discharge procedures and six minimum control measures but has not yet moved to a formal discharge‑sampling program.

• Board members asked about the scope of anticipated changes; staff said they were in a “wait and see” posture pending the EPA’s final permit language.

• The board approved resolution 2025‑72 by voice vote; staff will monitor ILR40 finalization and return recommendations if the permit imposes new obligations.

The county will continue its current MS4 activities and will prepare to implement any legally required changes if the Illinois EPA adopts discharge monitoring or other new requirements in the final ILR40.