Tilden Mining Company L.C. — NPDES permit MI0038369: limits, due date and EPA's record

NPDES permit MI0038369 · Major NON-POTW · effective, expires 2026-10-01 · EPA's file as of 2026-09-19

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

Reporting

Reports are due about 21 days after each monitoring period ends (the most common figure among MI permits in EPA's filings — check your permit).

Limits in force (67)

Outfall	Parameter	Statistic	Limit	Months
002	pH	DAILY MN	= 6 SU	all year
002	pH	DAILY MN	>= 6.5 SU	all year
002	pH	DAILY MX	= 9 SU	all year
002	pH	DAILY MX	<= 9 SU	all year
002	Solids, total suspended	MO AVG	= 20 mg/L	all year
002	Solids, total suspended	DAILY MX	= 30 mg/L	all year
002	Phosphorus, total [as P]	DAILY MX	report only	all year
002	Phosphorus, total [as P]	DAILY MX	report only	all year
002	Chloride [as Cl]	DAILY MX	report only	all year
002	Sulfate, total [as SO4]	DAILY MX	report only	all year
002	Arsenic, total [as As]	DAILY MX	report only	all year
002	Copper, total [as Cu]	DAILY MX	report only	all year
002	Iron, dissolved [as Fe]	MO AVG	= 1 mg/L	all year
002	Iron, dissolved [as Fe]	DAILY MX	= 2 mg/L	all year
002	Vanadium, total [as V]	DAILY MX	report only	all year
002	Selenium, total [as Se]	MO AVG	<= 5.1 ug/L	all year
002	Selenium, total [as Se]	DAILY MX	report only	all year
002	Selenium, total [as Se]	MO AVG	<= 1.1 lb/d	all year
002	Selenium, total [as Se]	DAILY MX	report only	all year
002	Toxicity, choice of species	MO AVG	report only	all year
002	Toxicity, choice of species	DAILY MX	report only	all year
002	Toxicity, choice of species	MO AVG	<= 1 tox chronic	all year
002	Toxicity, choice of species	DAILY MX	report only	all year
002	Flow, in conduit or thru treatment plant	MO AVG	report only	all year
002	Flow, in conduit or thru treatment plant	MO AVG	report only	all year
002	Flow, in conduit or thru treatment plant	DAILY MX	report only	all year
002	Flow, in conduit or thru treatment plant	DAILY MX	report only	all year
002	Chlorine, total residual	DAILY MN	report only	all year
002	Hematite Production	DAILY MX	report only	all year
002	Toxicity [acute], Ceriodaphnia dubia	DAILY MX	report only	all year
002	Toxicity [acute], Ceriodaphnia dubia	DAILY MX	report only	all year
002	Solids, total dissolved	MO AVG	report only	all year
002	Solids, total dissolved	DAILY MX	report only	all year
002	Mercury, total [as Hg]	MO AVG	report only	all year
002	Mercury, total [as Hg]	DAILY MX	report only	all year
002	Mercury, total [as Hg]	MO AVG	report only	all year
002	Mercury, total [as Hg]	DAILY MX	report only	all year
002	Coliform, fecal general	DAILY MX	report only	all year
002	Outfall observation,visual, y/n response	VALUE	report only	all year
002	TU Static 24 Hr Acute Pimephales promelas	DAILY MX	report only	all year
002	Static 48 Hr Chronic Pimphales Promelas	MO AVG	report only	all year
002	Static 48 Hr Chronic Pimphales Promelas	DAILY MX	report only	all year
003	pH	DAILY MN	>= 6.5 SU	all year
003	pH	DAILY MX	<= 9 SU	all year
003	Solids, total suspended	MO AVG	<= 20 mg/L	all year
003	Solids, total suspended	DAILY MX	<= 30 mg/L	all year
003	Arsenic, total [as As]	DAILY MX	report only	all year
003	Cadmium, total [as Cd]	DAILY MX	report only	all year
003	Copper, total [as Cu]	DAILY MX	report only	all year
003	Iron, dissolved [as Fe]	MO AVG	<= 1 mg/L	all year
003	Iron, dissolved [as Fe]	DAILY MX	<= 2 mg/L	all year
003	Lead, total [as Pb]	DAILY MX	report only	all year
003	Nickel, total [as Ni]	DAILY MX	report only	all year
003	Zinc, total [as Zn]	DAILY MX	report only	all year
003	Selenium, total [as Se]	MO AVG	<= 7.1 ug/L	all year
003	Selenium, total [as Se]	DAILY MX	report only	all year
003	Selenium, total [as Se]	MO AVG	<= .2 lb/d	all year
003	Selenium, total [as Se]	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	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	report only	all year
003	Mercury, total [as Hg]	DAILY MX	report only	all year
003	Mercury, total [as Hg]	MO AVG	report only	all year
003	Mercury, total [as Hg]	DAILY MX	report only	all year
003	Outfall observation,visual, y/n response	VALUE	report only	all year