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Dynegy Midwest Generation LLC

Electric Services, major discharger, Hennepin, Illinois. NPDES permit IL0001554 expired Sep 30, 2026; its limits still apply. Last 12 months: no values over a limit. Source: EPA ECHO, Oct 22, 2026.

Reports due
About 25 days after each period: form 0 monthly (10 values), form S monthly (23 values)
Last report on file
August 2026
Oct 2024 – Sep 2025
0 values over a limit, 0 required values missing, 0 of 24 reports late

Limits in force (33)

ParameterStatisticLimitMonths
pHmonthly minimum≥ 6 SUall year
pHmonthly maximum≤ 9 SUall year
Solids, total suspended30-day average≤ 15 mg/Lall year
Solids, total suspendeddaily maximum≤ 30 mg/Lall year
Oil & Greasedaily maximumreport only (mg/L)all year
Cyanide, total [as CN]daily maximumreport only (ug/L)all year
Cyanide, free [amenable to chlorination]daily maximumreport only (ug/L)all year
Sulfate, total [as SO4]daily maximumreport only (mg/L)all year
Fluoride, total [as F]daily maximumreport only (mg/L)all year
Arsenic, total [as As]daily maximumreport only (mg/L)all year
Barium, total [as Ba]daily maximumreport only (mg/L)all year
Boron, total [as B]daily maximumreport only (mg/L)all year
Cadmium, total [as Cd]daily maximumreport only (mg/L)all year
Chromium, hexavalent [as Cr]daily maximum≤ .016 mg/Lall year
Chromium, total [as Cr]daily maximumreport only (mg/L)all year
Copper, total [as Cu]daily maximumreport only (mg/L)all year
Iron, dissolved [as Fe]daily maximumreport only (mg/L)all year
Lead, total [as Pb]daily maximumreport only (mg/L)all year
Manganese, total [as Mn]daily maximumreport only (mg/L)all year
Thallium, total [as Tl]daily maximumreport only (mg/L)all year
Nickel, total [as Ni]daily maximumreport only (mg/L)all year
Silver, total [as Ag]daily maximumreport only (mg/L)all year
Zinc, total [as Zn]daily maximumreport only (mg/L)all year
Antimony, total [as Sb]daily maximumreport only (mg/L)all year
Selenium, total [as Se]daily maximumreport only (mg/L)all year
Oil and grease30-day average≤ 15 mg/Lall year
Oil and greasedaily maximum≤ 20 mg/Lall year
Radium 226, totaldaily maximumreport only (pCi/mL)all year
Radium 228, totaldaily maximumreport only (pCi/mL)all year
Phenolics, total recoverabledaily maximumreport only (mg/L)all year
Flow, in conduit or thru treatment plantmonthly averagereport only (MGD)all year
Flow, in conduit or thru treatment plantdaily maximumreport only (MGD)all year
Mercury, total [as Hg]rolling average≤ 12 ng/Lall year

How strict are these limits?

Cited limits by parameter: Illinois's rules and the federal ones.

Same industry: the 45 Electric Services permits in Illinois.

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On EPA ECHO: Facility report · DMR history

Your permit document is the final word. As JSON: /api/v1/permits/IL0001554 · MCP: https://passage-data.com/mcp