GenOn MD Ash Management, LLC — NPDES permit MD0057584: limits, due date and EPA's record

NPDES permit MD0057584 · Minor NON-POTW · effective, expires 2030-02-28 · EPA's file as of 2026-09-19

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

Reporting

Reports are due about 28 days after each monitoring period ends (read off this permit's own late-day counts in EPA's filings).

Limits in force (55)

Outfall	Parameter	Statistic	Limit	Months
003	Conductivity	MO AVG	report only	all year
003	Conductivity	DAILY MX	report only	all year
003	Oxygen, dissolved [DO]	MINIMUM	>= 5 mg/L	all year
003	pH	MINIMUM	>= 6.5 SU	all year
003	pH	DAILY MX	<= 8.5 SU	all year
003	Solids, total suspended	MO AVG	<= 30 mg/L	all year
003	Solids, total suspended	DAILY MX	<= 70 mg/L	all year
003	Oil & Grease	MO AVG	<= 15 mg/L	all year
003	Oil & Grease	DAILY MX	<= 20 mg/L	all year
003	Nitrogen, total [as N]	MO AVG	report only	all year
003	Nitrogen, total [as N]	DAILY MX	report only	all year
003	Nitrogen, total [as N]	MO AVG	report only	all year
003	Nitrogen, total [as N]	DAILY MX	report only	all year
003	Nitrogen, ammonia total [as N]	MO AVG	report only	all year
003	Nitrogen, ammonia total [as N]	DAILY MX	report only	all year
003	Phosphorus, total [as P]	MO AVG	report only	all year
003	Phosphorus, total [as P]	DAILY MX	report only	all year
003	Phosphorus, total [as P]	MO AVG	report only	all year
003	Phosphorus, total [as P]	DAILY MX	report only	all year
003	Hardness, total [as CaCO3]	MO AVG	report only	all year
003	Hardness, total [as CaCO3]	DAILY MX	report only	all year
003	Arsenic, Inorganic	MO AVG	report only	all year
003	Arsenic, Inorganic	DAILY MX	report only	all year
003	Arsenic, total [as As]	MO AVG	<= 150 ug/L	all year
003	Arsenic, total [as As]	DAILY MX	<= 340 ug/L	all year
003	Boron, total [as B]	MO AVG	report only	all year
003	Boron, total [as B]	DAILY MX	report only	all year
003	Cadmium, total [as Cd]	MO AVG	<= .25 ug/L	all year
003	Cadmium, total [as Cd]	DAILY MX	<= 2 ug/L	all year
003	Chromium, total [as Cr]	MO AVG	report only	all year
003	Chromium, total [as Cr]	DAILY MX	report only	all year
003	Copper, total [as Cu]	MO AVG	<= 9 ug/L	all year
003	Copper, total [as Cu]	DAILY MX	<= 13 ug/L	all year
003	Iron, total [as Fe]	MO AVG	<= 3.5 mg/L	all year
003	Iron, total [as Fe]	DAILY MX	<= 7 mg/L	all year
003	Lead, total [as Pb]	MO AVG	<= 2.5 ug/L	all year
003	Lead, total [as Pb]	DAILY MX	<= 65 ug/L	all year
003	Nickel, total [as Ni]	MO AVG	<= 52 ug/L	all year
003	Nickel, total [as Ni]	DAILY MX	<= 470 ug/L	all year
003	Zinc, total [as Zn]	MO AVG	<= 120 ug/L	all year
003	Zinc, total [as Zn]	DAILY MX	<= 120 ug/L	all year
003	Selenium, total [as Se]	MO AVG	<= 5 ug/L	all year
003	Selenium, total [as Se]	DAILY MX	<= 20 ug/L	all year
003	Whole effluent toxicity	MO AVG	report only	all year
003	Whole effluent toxicity	DAILY MX	<= 1 %	all year
003	Chloride	MO AVG	<= 230 mg/L	all year
003	Chloride	DAILY MX	<= 860 mg/L	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	Sulfates, total [as SO4]	MO AVG	report only	all year
003	Sulfates, total [as SO4]	DAILY MX	report only	all year
003	Solids, total dissolved	MO AVG	report only	all year
003	Solids, total dissolved	DAILY MX	report only	all year
003	Mercury, total [as Hg]	MO AVG	<= .77 ug/L	all year
003	Mercury, total [as Hg]	DAILY MX	<= 1.4 ug/L	all year