Illinois
The stormwater permit for construction in Illinois
Illinois runs its own NPDES programme, so a state issued construction general permit governs. Below is what our engine can say about it, and where we have not read that permit, what it will not say.
Governing permit
General NPDES Permit No. ILR10 for Storm Water Discharges From Construction Site Activities
- Issued by
- Illinois Environmental Protection Agency (Illinois EPA), Division of Water Pollution Control
- Permit number
- ILR10
- Version determined against
- as published by the state agency
Who may prepare the plan
No preparer credential foundNo preparer credential was found for Illinois. On what we have verified, a generated plan can be adopted by the operator without a credentialed signature. Local ordinances can still be stricter than state law.
State law is a floor: Cook County MWRD ordinance section 303.2.A(3) effectively requires a PE seal within Illinois.
No permit section cited. Confirm this with your permitting authority.
Does a site in Illinois need coverage
Worked for a one acre site as a reference point. Change the acreage in the tool below and the answer, and its reasoning, change with it.
Coverage
Permit coverage required
The project disturbs 1 acres, at or above the 1 acre threshold, so it needs permit coverage.
Determined against dataset version 2026-07-19.
Read these before you act on the answer
- We have identified General NPDES Permit No. ILR10 for Storm Water Discharges From Construction Site Activities as the governing permit but have not loaded its requirements. The requirements below are not shown because we will not substitute the federal permit's rules for a state's. Confirm with Illinois Environmental Protection Agency (Illinois EPA), Division of Water Pollution Control.
- No preparer credential was found for Illinois. On what we have verified, a generated plan can be adopted by the operator without a credentialed signature. Local ordinances can still be stricter than state law.
- Basinwise does not perform the physical site inspections the permit requires. Those must be carried out on site by a qualified person.
How this answer was reached, step by step
- 1
Coverage threshold
The project disturbs 1 acres, at or above the 1 acre threshold, so it needs permit coverage.
- 2
Permitting authority
Illinois. The state runs its own programme under ILR10.
- 3
Preparer credential
No preparer credential was found for Illinois. On what we have verified, a generated plan can be adopted by the operator without a credentialed signature. Local ordinances can still be stricter than state law.
What to do next
- 1. Confirm the governing permit. Read General NPDES Permit No. ILR10 for Storm Water Discharges From Construction Site Activities directly. It is linked above, and it is the document an inspector will hold you to. Illinois Environmental Protection Agency (Illinois EPA), Division of Water Pollution Control
- 2. Settle the preparer question before you draft. Getting this wrong costs a redraft at best. The detail is on the credential page for this state. Preparer credential in Illinois
- 3. Screen the site. Run the real acreage and receiving water facts through the tool below. You get the inspection frequency, the stabilisation deadlines and the filing path with the permit section behind each.
- 4. Read the requirements in full. SWPPP requirements in Illinois
Screen a Illinois site now
Runs in your browser. Nothing about the site is transmitted.
What people ask about the Illinois construction stormwater permit
Do I need a stormwater permit for a construction site in Illinois?
Permit coverage is triggered at one acre of land disturbance, and below one acre if the project is part of a larger common plan of development or sale that will ultimately disturb an acre or more. The project disturbs 1 acres, at or above the 1 acre threshold, so it needs permit coverage.
Who issues the construction stormwater permit in Illinois?
Illinois Environmental Protection Agency (Illinois EPA), Division of Water Pollution Control issues General NPDES Permit No. ILR10 for Storm Water Discharges From Construction Site Activities.
Does Illinois require a qualified preparer for the plan?
No preparer credential was found for Illinois. On what we have verified, a generated plan can be adopted by the operator without a credentialed signature. Local ordinances can still be stricter than state law.
Keep the record Illinois will ask you for
The screening is free. Holding the written plan and the retained inspection log is what the permit actually demands.