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Matheson Tri-Gas Inc

Industrial Gases, Mapleton, Illinois. NPDES permit IL0070122 expired Dec 31, 2024; its limits still apply. Last 12 months: over a limit 2 times (last February 2026), 15 required values missing, 5 of 16 reports late. Source: EPA ECHO, Oct 22, 2026.

Reports due
About 25 days after each period: form 0 monthly (6 values), form Q quarterly
Last report on file
September 2026
Oct 2024 – Sep 2025
0 values over a limit, 0 required values missing, 3 of 16 reports late

Last 12 months (Oct 1, 2025 – Sep 30, 2026)

Period endingParameterReportedLimitOver by
February 2026Chlorine, total residual, daily maximum.06 mg/L≤ .05 mg/L20%
February 2026Temperature, water deg. fahrenheit, monthly maximum64 deg F≤ 63 deg F2%

Limits in force (17)

ParameterStatisticLimitMonths
Temperature, water deg. fahrenheitmonthly maximum≤ 93 deg FApr–Nov
Temperature, water deg. fahrenheitmonthly maximum≤ 63 deg FJan, Feb, Mar, Dec
pHmonthly minimum≥ 6.5 SUall year
pHmonthly maximum≤ 9 SUall year
Solids, total suspended30-day average≤ 15 mg/Lall year
Solids, total suspended30-day average≤ 15 mg/Lall year
Solids, total suspendeddaily maximum≤ 30 mg/Lall year
Solids, total suspendeddaily maximum≤ 30 mg/Lall year
Chloride [as Cl]daily maximum≤ 5400 mg/Lall year
Chloride [as Cl]daily maximum≤ 5400 mg/Lall year
Iron, total [as Fe]30-day average≤ 2 mg/Lall year
Iron, total [as Fe]30-day average≤ 2 mg/Lall year
Iron, total [as Fe]daily maximum≤ 4 mg/Lall year
Iron, total [as Fe]daily maximum≤ 4 mg/Lall year
Flow, in conduit or thru treatment plantmonthly averagereport only (MGD)all year
Flow, in conduit or thru treatment plantdaily maximumreport only (MGD)all year
Chlorine, total residualdaily maximum≤ .05 mg/Lall year

How strict are these limits?

Cited limits by parameter: Illinois's rules and the federal ones.

Same industry: the 58 Chemicals and Allied Products permits in Illinois.

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On EPA ECHO: Facility report · DMR history

Your permit document is the final word. As JSON: /api/v1/permits/IL0070122 · MCP: https://passage-data.com/mcp