MATHESON TRI-GAS INC — NPDES permit IL0070122: limits, due date and EPA's record

NPDES permit IL0070122 · Minor NON-POTW · administratively continued, expires 2024-12-31 · EPA's file as of 2026-09-19

Watch this permit — $79 a month. Every Monday, from EPA's newest files: the next report due and when, whether EPA's file holds your last one, any change to this permit's limits or status, and the renewal date.

This permit expired on 2024-12-31 and is administratively continued: its last limits keep applying until a new permit is issued, and EPA still expects the reports.

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

Last period with anything received: 2026-08-31. Most often over: Chlorine, total residual (1), Temperature, water deg. fahrenheit (1).

Reporting

Reports are due about 25 days after each monitoring period ends (read off this permit's own late-day counts in EPA's filings).

Limits in force (17)

Outfall	Parameter	Statistic	Limit	Months
001	Temperature, water deg. fahrenheit	MO MAX	<= 93 deg F	Apr, May, Jun, Jul, Aug, Sep, Oct, Nov
001	Temperature, water deg. fahrenheit	MO MAX	<= 63 deg F	Jan, Feb, Mar, Dec
001	pH	MO MIN	>= 6.5 SU	all year
001	pH	MO MAX	<= 9 SU	all year
001	Solids, total suspended	30DA AVG	<= 15 mg/L	all year
001	Solids, total suspended	30DA AVG	<= 15 mg/L	all year
001	Solids, total suspended	DAILY MX	<= 30 mg/L	all year
001	Solids, total suspended	DAILY MX	<= 30 mg/L	all year
001	Chloride [as Cl]	DAILY MX	<= 5400 mg/L	all year
001	Chloride [as Cl]	DAILY MX	<= 5400 mg/L	all year
001	Iron, total [as Fe]	30DA AVG	<= 2 mg/L	all year
001	Iron, total [as Fe]	30DA AVG	<= 2 mg/L	all year
001	Iron, total [as Fe]	DAILY MX	<= 4 mg/L	all year
001	Iron, total [as Fe]	DAILY MX	<= 4 mg/L	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	Chlorine, total residual	DAILY MX	<= .05 mg/L	all year