DYNEGY MIDWEST GENERATION LLC — NPDES permit IL0001554: limits, due date and EPA's record

NPDES permit IL0001554 · Major NON-POTW · effective, expires 2026-09-30 · EPA's file as of 2026-09-19

EPA's record, 2025-09-01 to 2026-08-31

Reporting

Reports are due about 25 days after each monitoring period ends (the most common figure among IL permits in EPA's filings — check your permit).

Limits in force (33)

Outfall	Parameter	Statistic	Limit	Months
003	pH	MO MIN	>= 6 SU	all year
003	pH	MO MAX	<= 9 SU	all year
003	Solids, total suspended	30DA AVG	<= 15 mg/L	all year
003	Solids, total suspended	DAILY MX	<= 30 mg/L	all year
003	Oil & Grease	DAILY MX	report only	all year
003	Cyanide, total [as CN]	DAILY MX	report only	all year
003	Cyanide, free [amenable to chlorination]	DAILY MX	report only	all year
003	Sulfate, total [as SO4]	DAILY MX	report only	all year
003	Fluoride, total [as F]	DAILY MX	report only	all year
003	Arsenic, total [as As]	DAILY MX	report only	all year
003	Barium, total [as Ba]	DAILY MX	report only	all year
003	Boron, total [as B]	DAILY MX	report only	all year
003	Cadmium, total [as Cd]	DAILY MX	report only	all year
003	Chromium, hexavalent [as Cr]	DAILY MX	<= .016 mg/L	all year
003	Chromium, total [as Cr]	DAILY MX	report only	all year
003	Copper, total [as Cu]	DAILY MX	report only	all year
003	Iron, dissolved [as Fe]	DAILY MX	report only	all year
003	Lead, total [as Pb]	DAILY MX	report only	all year
003	Manganese, total [as Mn]	DAILY MX	report only	all year
003	Thallium, total [as Tl]	DAILY MX	report only	all year
003	Nickel, total [as Ni]	DAILY MX	report only	all year
003	Silver, total [as Ag]	DAILY MX	report only	all year
003	Zinc, total [as Zn]	DAILY MX	report only	all year
003	Antimony, total [as Sb]	DAILY MX	report only	all year
003	Selenium, total [as Se]	DAILY MX	report only	all year
003	Oil and grease	30DA AVG	<= 15 mg/L	all year
003	Oil and grease	DAILY MX	<= 20 mg/L	all year
003	Radium 226, total	DAILY MX	report only	all year
003	Radium 228, total	DAILY MX	report only	all year
003	Phenolics, total recoverable	DAILY MX	report only	all year
003	Flow, in conduit or thru treatment plant	MO AVG	report only	all year
003	Flow, in conduit or thru treatment plant	DAILY MX	report only	all year
003	Mercury, total [as Hg]	ROLL AVG	<= 12 ng/L	all year