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Heidelberg Materials US Cement LLC

Cement, Hydraulic, Mason City, Iowa. NPDES permit IA0001945, in force until Jan 31, 2027. Last 12 months: over a limit 2 times (last June 2026). Source: EPA ECHO, Oct 22, 2026.

Reports due
About 15 days after each period: outfall 001 form A monthly (20 values), outfall 002 form A monthly (3 values), outfall 004 form A monthly (3 values), outfall 007 form A monthly (3 values), outfall 012 form A monthly (3 values)
Renewal application due
Aug 4, 2026 · 180 days before expiry; your permit may set another date
Last report on file
August 2026
Oct 2024 – Sep 2025
1 value over a limit, 0 required values missing, 10 of 60 reports late

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

Period endingParameterReportedLimitOver by
March 2026Solids, total suspended, daily maximum65.25≤ 50 mg/L31%
June 2026Solids, total suspended, daily maximum124≤ 50 mg/L148%

Limits in force (32)

ParameterStatisticLimitMonthsOutfall
Oxygen, dissolved [DO]30-day averagereport only (mg/L)all year001
Oxygen, dissolved [DO]daily maximumreport only (mg/L)all year001
pHdaily minimum≥ 6.5 SUall year001
pHdaily maximum≤ 9 SUall year001
Solids, total suspended30-day average≤ 30 mg/Lall year001
Solids, total suspendeddaily maximum≤ 45 mg/Lall year001
Solids, total suspended30-day average≤ 1.5 lb/dall year001
Solids, total suspendeddaily maximum≤ 2.3 lb/dall year001
Nitrogen, total [as N]30-day averagereport only (mg/L)all year001
Nitrogen, total [as N]daily maximumreport only (mg/L)all year001
Nitrogen, total [as N]30-day averagereport only (lb/d)all year001
Nitrogen, total [as N]daily maximumreport only (lb/d)all year001
Chloride [as Cl]30-day average≤ 389 mg/Lall year001
Chloride [as Cl]daily maximum≤ 629 mg/Lall year001
Chloride [as Cl]30-day average≤ 19.4 lb/dall year001
Chloride [as Cl]daily maximum≤ 31.5 lb/dall year001
BOD, carbonaceous [5 day, 20 C]30-day average≤ 25 mg/Lall year001
BOD, carbonaceous [5 day, 20 C]daily maximum≤ 40 mg/Lall year001
BOD, carbonaceous [5 day, 20 C]30-day average≤ 1.25 lb/dall year001
BOD, carbonaceous [5 day, 20 C]daily maximum≤ 2 lb/dall year001
pHdaily minimum≥ 6.5 SUall year002
pHdaily maximum≤ 9 SUall year002
Solids, total suspendeddaily maximum≤ 50 mg/Lall year002
pHdaily minimum≥ 6.5 SUall year004
pHdaily maximum≤ 9 SUall year004
Solids, total suspendeddaily maximum≤ 50 mg/Lall year004
pHdaily minimum≥ 6.5 SUall year007
pHdaily maximum≤ 9 SUall year007
Solids, total suspendeddaily maximum≤ 50 mg/Lall year007
pHdaily minimum≥ 6.5 SUall year012
pHdaily maximum≤ 9 SUall year012
Solids, total suspendeddaily maximum≤ 50 mg/Lall year012

How strict are these limits?

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

Same industry: the 5 Stone, Clay, Glass and Concrete Products permits in Iowa.

Check this month's numbers Email me before each report is due

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On EPA ECHO: Facility report · DMR history

Your permit document is the final word. As JSON: /api/v1/permits/IA0001945 · MCP: https://passage-data.com/mcp