Passage Data · Check a report · Use it from your AI

City of Sioux Center

Sewage treatment plant, major discharger, Sioux Center, Iowa. NPDES permit IA0033731, in force until Apr 30, 2031. Last 12 months: over a limit 6 times (last April 2026). Source: EPA ECHO, Oct 22, 2026.

Reports due
About 15 days after each period: form A monthly (56 values)
Last report on file
September 2026
Oct 2024 – Sep 2025
0 values over a limit, 0 required values missing, 2 of 12 reports late

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

Period endingParameterReportedLimitOver by
November 2025Chromium, total [as Cr], daily maximum.0335≤ .01629 mg/L106%
February 2026Chloride [as Cl], 30-day average596.25≤ 491 mg/L21%
March 2026Chloride [as Cl], 30-day average619.4≤ 491 mg/L26%
March 2026Oxygen, dissolved [DO], daily minimum3.7≥ 5 mg/L26%
April 2026Chloride [as Cl], 30-day average573.25≤ 491 mg/L17%
April 2026Selenium, total [as Se], 30-day average.005565≤ .005 mg/L11%

Limits in force (100)

ParameterStatisticLimitMonths
Oxygen, dissolved [DO]daily minimum≥ 5 mg/Lall year
BOD, 5-day, 20 deg. C30-day averagereport only (mg/L)all year
BOD, 5-day, 20 deg. Cdaily maximumreport only (mg/L)all year
BOD, 5-day, 20 deg. C30-day averagereport only (lb/d)all year
BOD, 5-day, 20 deg. Cdaily maximumreport only (lb/d)all year
pHdaily minimum≥ 6.5 SUall year
pHdaily maximum≤ 9 SUall year
pH30-day averagereport only (SU)all year
pHdaily maximumreport only (SU)all year
Solids, total suspended30-day average≤ 30 mg/Lall year
Solids, total suspended7-day average≤ 45 mg/Lall year
Solids, total suspended30-day average≤ 553 lb/dall year
Solids, total suspended7-day average≤ 829 lb/dall year
Solids, total suspended30-day averagereport only (mg/L)all year
Solids, total suspendeddaily maximumreport only (mg/L)all year
Solids, total suspended30-day averagereport only (lb/d)all year
Solids, total suspendeddaily maximumreport only (lb/d)all year
Nitrogen, total [as N]30-day averagereport only (mg/L)all year
Nitrogen, total [as N]daily maximumreport only (mg/L)all year
Nitrogen, total [as N]30-day averagereport only (lb/d)all year
Nitrogen, total [as N]daily maximumreport only (lb/d)all year
Nitrogen, ammonia total [as N]30-day average≤ 3.4 mg/LMar
Nitrogen, ammonia total [as N]30-day average≤ 1.6 mg/LOct
Nitrogen, ammonia total [as N]30-day average≤ 1 mg/LJul
Nitrogen, ammonia total [as N]30-day average≤ 2.5 mg/LDec
Nitrogen, ammonia total [as N]30-day average≤ 3.4 mg/LJan
Nitrogen, ammonia total [as N]30-day average≤ 1.5 mg/LApr
Nitrogen, ammonia total [as N]30-day average≤ 2.3 mg/LNov
Nitrogen, ammonia total [as N]30-day average≤ 1.3 mg/LJun
Nitrogen, ammonia total [as N]30-day average≤ 1 mg/LAug
Nitrogen, ammonia total [as N]30-day average≤ 1.7 mg/LMay
Nitrogen, ammonia total [as N]30-day average≤ 4 mg/LFeb
Nitrogen, ammonia total [as N]30-day average≤ 1.1 mg/LSep
Nitrogen, ammonia total [as N]daily maximum≤ 14.7 mg/LMar
Nitrogen, ammonia total [as N]daily maximum≤ 14.5 mg/LOct
Nitrogen, ammonia total [as N]daily maximum≤ 8.1 mg/LJul
Nitrogen, ammonia total [as N]daily maximum≤ 16 mg/LDec
Nitrogen, ammonia total [as N]daily maximum≤ 15.2 mg/LJan
Nitrogen, ammonia total [as N]daily maximum≤ 15.7 mg/LApr
Nitrogen, ammonia total [as N]daily maximum≤ 14.7 mg/LNov
Nitrogen, ammonia total [as N]daily maximum≤ 11.2 mg/LJun
Nitrogen, ammonia total [as N]daily maximum≤ 7.8 mg/LAug
Nitrogen, ammonia total [as N]daily maximum≤ 15.2 mg/LMay
Nitrogen, ammonia total [as N]daily maximum≤ 14.2 mg/LFeb
Nitrogen, ammonia total [as N]daily maximum≤ 10.1 mg/LSep
Nitrogen, ammonia total [as N]30-day average≤ 62.8 lb/dMar
Nitrogen, ammonia total [as N]30-day average≤ 28.7 lb/dOct
Nitrogen, ammonia total [as N]30-day average≤ 18.5 lb/dJul
Nitrogen, ammonia total [as N]30-day average≤ 45.6 lb/dDec
Nitrogen, ammonia total [as N]30-day average≤ 62.8 lb/dJan
Nitrogen, ammonia total [as N]30-day average≤ 28.1 lb/dApr
Nitrogen, ammonia total [as N]30-day average≤ 42.8 lb/dNov
Nitrogen, ammonia total [as N]30-day average≤ 24.1 lb/dJun
Nitrogen, ammonia total [as N]30-day average≤ 17.6 lb/dAug
Nitrogen, ammonia total [as N]30-day average≤ 32 lb/dMay
Nitrogen, ammonia total [as N]30-day average≤ 72.8 lb/dFeb
Nitrogen, ammonia total [as N]30-day average≤ 19.5 lb/dSep
Nitrogen, ammonia total [as N]daily maximum≤ 270.7 lb/dMar
Nitrogen, ammonia total [as N]daily maximum≤ 256.2 lb/dOct
Nitrogen, ammonia total [as N]daily maximum≤ 141.9 lb/dJul
Nitrogen, ammonia total [as N]daily maximum≤ 294.2 lb/dDec
Nitrogen, ammonia total [as N]daily maximum≤ 279.9 lb/dJan
Nitrogen, ammonia total [as N]daily maximum≤ 289.4 lb/dApr
Nitrogen, ammonia total [as N]daily maximum≤ 270.7 lb/dNov
Nitrogen, ammonia total [as N]daily maximum≤ 197.2 lb/dJun
Nitrogen, ammonia total [as N]daily maximum≤ 134.5 lb/dAug
Nitrogen, ammonia total [as N]daily maximum≤ 279.9 lb/dMay
Nitrogen, ammonia total [as N]daily maximum≤ 261.7 lb/dFeb
Nitrogen, ammonia total [as N]daily maximum≤ 175.1 lb/dSep
Nitrogen, Kjeldahl, total [as N]30-day averagereport only (mg/L)all year
Nitrogen, Kjeldahl, total [as N]daily maximumreport only (mg/L)all year
Nitrogen, Kjeldahl, total [as N]30-day averagereport only (lb/d)all year
Nitrogen, Kjeldahl, total [as N]daily maximumreport only (lb/d)all year
Phosphorus, total [as P]30-day averagereport only (mg/L)all year
Phosphorus, total [as P]daily maximumreport only (mg/L)all year
Phosphorus, total [as P]30-day averagereport only (lb/d)all year
Phosphorus, total [as P]daily maximumreport only (lb/d)all year
Cyanide, total [as CN]30-day average≤ .0052 mg/Lall year
Cyanide, total [as CN]daily maximum≤ .022 mg/Lall year
Cyanide, total [as CN]30-day average≤ .09584 lb/dall year
Cyanide, total [as CN]daily maximum≤ .4055 lb/dall year
Chromium, total [as Cr]30-day average≤ .01143 mg/Lall year
Chromium, total [as Cr]daily maximum≤ .01629 mg/Lall year
Chromium, total [as Cr]30-day average≤ .2108 lb/dall year
Chromium, total [as Cr]daily maximum≤ .3003 lb/dall year
Copper, total [as Cu]30-day average≤ .0471 mg/Lall year
Copper, total [as Cu]daily maximum≤ .0835 mg/Lall year
Copper, total [as Cu]30-day average≤ .869 lb/dall year
Copper, total [as Cu]daily maximum≤ 1.54 lb/dall year
Selenium, total [as Se]30-day average≤ .005 mg/Lall year
Selenium, total [as Se]daily maximum≤ .0193 mg/Lall year
Selenium, total [as Se]30-day average≤ .09216 lb/dall year
Selenium, total [as Se]daily maximum≤ .3557 lb/dall year
E. coligeometric mean≤ 444 #/100mLMar–Nov
Toxicity [acute], Ceriodaphnia dubiadaily maximum≤ 1 N=0;Y=1all year
Toxicity [acute], Pimephales promelas [Fathead Minnow]daily maximum≤ 1 N=0;Y=1all year
BOD, carbonaceous [5 day, 20 C]30-day average≤ 25 mg/Lall year
BOD, carbonaceous [5 day, 20 C]7-day average≤ 40 mg/Lall year
BOD, carbonaceous [5 day, 20 C]30-day average≤ 461 lb/dall year
BOD, carbonaceous [5 day, 20 C]7-day average≤ 737 lb/dall year

How strict are these limits?

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

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

· Save this facility as a site · Superfund sites nearby · Your permits on one board

On EPA ECHO: Facility report · DMR history

Your permit document is the final word. As JSON: /api/v1/permits/IA0033731 · MCP: https://passage-data.com/mcp