MATHESON TRI-GAS INC — NPDES permit IN0001970: limits, due date and EPA's record

NPDES permit IN0001970 · Minor NON-POTW · effective, expires 2026-10-31 · EPA's file as of 2026-09-19

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

Last period with anything received: 2026-08-31. Most often over: Temperature, water deg. fahrenheit (1), Oil and grease, hexane extr method (1).

Reporting

Reports are due about 29 days after each monitoring period ends (read off this permit's own late-day counts in EPA's filings).

Limits in force (40)

Outfall	Parameter	Statistic	Limit	Months
001	pH	DAILY MN	>= 6 SU	all year
001	pH	DAILY MX	<= 9 SU	all year
001	Solids, total suspended	DAILY MX	<= 25 mg/L	all year
001	Nitrogen, ammonia total [as N]	MO AVG	report only	all year
001	Nitrogen, ammonia total [as N]	DAILY MX	report only	all year
001	Flow, in conduit or thru treatment plant	MO AVG	report only	all year
001	Flow, in conduit or thru treatment plant	DAILY MX	report only	all year
001	E. coli, colony forming units [CFU]	MO GEO	<= 125 CFU/100mL	Apr, May, Jun, Jul, Aug, Sep, Oct
001	E. coli, colony forming units [CFU]	DAILY MX	<= 235 CFU/100mL	Apr, May, Jun, Jul, Aug, Sep, Oct
001	BOD, carbonaceous [5 day, 20 C]	MO AVG	<= 25 mg/L	all year
001	BOD, carbonaceous [5 day, 20 C]	DAILY MX	<= 40 mg/L	all year
001	Flow, total	MO TOTAL	report only	all year
002	Temperature, water deg. fahrenheit	DAILY MX	<= 73 deg F	Apr, Nov
002	Temperature, water deg. fahrenheit	DAILY MX	<= 63 deg F	Mar
002	Temperature, water deg. fahrenheit	DAILY MX	<= 53 deg F	Jan, Feb
002	Temperature, water deg. fahrenheit	DAILY MX	<= 83 deg F	May
002	Temperature, water deg. fahrenheit	DAILY MX	<= 90 deg F	Jun, Sep
002	Temperature, water deg. fahrenheit	DAILY MX	<= 81 deg F	Oct
002	Temperature, water deg. fahrenheit	DAILY MX	<= 92 deg F	Jul, Aug
002	Temperature, water deg. fahrenheit	DAILY MX	<= 60 deg F	Dec
002	pH	DAILY MN	>= 6 SU	all year
002	pH	DAILY MX	<= 9 SU	all year
002	Solids, total suspended	MO AVG	report only	all year
002	Solids, total suspended	DAILY MX	report only	all year
002	Oil and grease, hexane extr method	DAILY MX	<= 5 mg/L	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, total	MO TOTAL	report only	all year
003	pH	DAILY MX	report only	Dec
003	pH	DAILY MX	report only	Dec
003	Solids, total suspended	DAILY MX	report only	Dec
003	Solids, total suspended	DAILY MX	report only	Dec
003	Oil and grease, hexane extr method	DAILY MX	report only	Dec
003	Oil and grease, hexane extr method	DAILY MX	report only	Dec
003	Chemical Oxygen Demand [COD]	DAILY MX	report only	Dec
003	Chemical Oxygen Demand [COD]	DAILY MX	report only	Dec
003	Storm water flow	DAILY MX	report only	Dec
003	Storm water flow	DAILY MX	report only	Dec
003	Flow, total	ANNL TOT	report only	Dec
003	Flow, total	ANNL TOT	report only	Dec