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City of Ames

Sewage treatment plant, major discharger, Ames, Iowa. NPDES permit IA0035955, in force until Feb 28, 2027. Last 12 months: no values over a limit. Source: EPA ECHO, Oct 22, 2026.

Reports due
About 15 days after each period: form A monthly (48 values)
Renewal application due
Sep 1, 2026 · 180 days before expiry; your permit may set another date
Last report on file
August 2026
Oct 2024 – Sep 2025
0 values over a limit, 1 required value missing, 0 of 12 reports late

Limits in force (136)

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≤ 3027 lb/dall year
Solids, total suspended7-day average≤ 4541 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, 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/LJan
Nitrogen, ammonia total [as N]30-day average≤ 1 mg/LAug
Nitrogen, ammonia total [as N]30-day average≤ 1.5 mg/LApr
Nitrogen, ammonia total [as N]30-day average≤ 1.7 mg/LMay
Nitrogen, ammonia total [as N]30-day average≤ 1.3 mg/LJun
Nitrogen, ammonia total [as N]30-day average≤ 1.1 mg/LSep
Nitrogen, ammonia total [as N]30-day average≤ 2.3 mg/LNov
Nitrogen, ammonia total [as N]30-day average≤ 1 mg/LJul
Nitrogen, ammonia total [as N]30-day average≤ 1.6 mg/LOct
Nitrogen, ammonia total [as N]30-day average≤ 2.5 mg/LDec
Nitrogen, ammonia total [as N]30-day average≤ 3.4 mg/LMar
Nitrogen, ammonia total [as N]30-day average≤ 4 mg/LFeb
Nitrogen, ammonia total [as N]daily maximum≤ 15.2 mg/LJan
Nitrogen, ammonia total [as N]daily maximum≤ 10 mg/LAug
Nitrogen, ammonia total [as N]daily maximum≤ 15.7 mg/LApr
Nitrogen, ammonia total [as N]daily maximum≤ 15.2 mg/LMay
Nitrogen, ammonia total [as N]daily maximum≤ 11.5 mg/LJun
Nitrogen, ammonia total [as N]daily maximum≤ 14 mg/LSep
Nitrogen, ammonia total [as N]daily maximum≤ 14.7 mg/LNov
Nitrogen, ammonia total [as N]daily maximum≤ 8.5 mg/LJul
Nitrogen, ammonia total [as N]daily maximum≤ 15.7 mg/LOct
Nitrogen, ammonia total [as N]daily maximum≤ 16 mg/LDec
Nitrogen, ammonia total [as N]daily maximum≤ 14.7 mg/LMar
Nitrogen, ammonia total [as N]daily maximum≤ 14.2 mg/LFeb
Nitrogen, ammonia total [as N]30-day average≤ 343.6 lb/dJan
Nitrogen, ammonia total [as N]30-day average≤ 96.3 lb/dAug
Nitrogen, ammonia total [as N]30-day average≤ 153.8 lb/dApr
Nitrogen, ammonia total [as N]30-day average≤ 175.4 lb/dMay
Nitrogen, ammonia total [as N]30-day average≤ 131 lb/dJun
Nitrogen, ammonia total [as N]30-day average≤ 106.6 lb/dSep
Nitrogen, ammonia total [as N]30-day average≤ 234.1 lb/dNov
Nitrogen, ammonia total [as N]30-day average≤ 101.4 lb/dJul
Nitrogen, ammonia total [as N]30-day average≤ 157 lb/dOct
Nitrogen, ammonia total [as N]30-day average≤ 249.7 lb/dDec
Nitrogen, ammonia total [as N]30-day average≤ 343.6 lb/dMar
Nitrogen, ammonia total [as N]30-day average≤ 398.8 lb/dFeb
Nitrogen, ammonia total [as N]daily maximum≤ 1532.7 lb/dJan
Nitrogen, ammonia total [as N]daily maximum≤ 1009 lb/dAug
Nitrogen, ammonia total [as N]daily maximum≤ 1584 lb/dApr
Nitrogen, ammonia total [as N]daily maximum≤ 1532.7 lb/dMay
Nitrogen, ammonia total [as N]daily maximum≤ 1161 lb/dJun
Nitrogen, ammonia total [as N]daily maximum≤ 1382.5 lb/dSep
Nitrogen, ammonia total [as N]daily maximum≤ 1482 lb/dNov
Nitrogen, ammonia total [as N]daily maximum≤ 858 lb/dJul
Nitrogen, ammonia total [as N]daily maximum≤ 1584 lb/dOct
Nitrogen, ammonia total [as N]daily maximum≤ 1610.8 lb/dDec
Nitrogen, ammonia total [as N]daily maximum≤ 1482 lb/dMar
Nitrogen, ammonia total [as N]daily maximum≤ 1432.7 lb/dFeb
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
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
E. coligeometric mean≤ 126 #/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≤ 20 mg/LOct
BOD, carbonaceous [5 day, 20 C]30-day average≤ 20 mg/LDec
BOD, carbonaceous [5 day, 20 C]30-day average≤ 20 mg/LFeb
BOD, carbonaceous [5 day, 20 C]30-day average≤ 20 mg/LApr
BOD, carbonaceous [5 day, 20 C]30-day average≤ 20 mg/LMay
BOD, carbonaceous [5 day, 20 C]30-day average≤ 20 mg/LNov
BOD, carbonaceous [5 day, 20 C]30-day average≤ 20 mg/LAug
BOD, carbonaceous [5 day, 20 C]30-day average≤ 20 mg/LMar
BOD, carbonaceous [5 day, 20 C]30-day average≤ 20 mg/LJan
BOD, carbonaceous [5 day, 20 C]30-day average≤ 20 mg/LJun
BOD, carbonaceous [5 day, 20 C]30-day average≤ 20 mg/LJul
BOD, carbonaceous [5 day, 20 C]30-day average≤ 20 mg/LSep
BOD, carbonaceous [5 day, 20 C]7-day average≤ 30 mg/LOct
BOD, carbonaceous [5 day, 20 C]7-day average≤ 30 mg/LDec
BOD, carbonaceous [5 day, 20 C]7-day average≤ 30 mg/LFeb
BOD, carbonaceous [5 day, 20 C]7-day average≤ 30 mg/LApr
BOD, carbonaceous [5 day, 20 C]7-day average≤ 30 mg/LMay
BOD, carbonaceous [5 day, 20 C]7-day average≤ 30 mg/LNov
BOD, carbonaceous [5 day, 20 C]daily maximum≤ 30 mg/LAug
BOD, carbonaceous [5 day, 20 C]7-day average≤ 30 mg/LMar
BOD, carbonaceous [5 day, 20 C]7-day average≤ 30 mg/LJan
BOD, carbonaceous [5 day, 20 C]daily maximum≤ 30 mg/LJun
BOD, carbonaceous [5 day, 20 C]daily maximum≤ 30 mg/LJul
BOD, carbonaceous [5 day, 20 C]daily maximum≤ 30 mg/LSep
BOD, carbonaceous [5 day, 20 C]30-day average≤ 2018 lb/dOct
BOD, carbonaceous [5 day, 20 C]30-day average≤ 2018 lb/dDec
BOD, carbonaceous [5 day, 20 C]30-day average≤ 2018 lb/dFeb
BOD, carbonaceous [5 day, 20 C]30-day average≤ 2018 lb/dApr
BOD, carbonaceous [5 day, 20 C]30-day average≤ 2018 lb/dMay
BOD, carbonaceous [5 day, 20 C]30-day average≤ 2018 lb/dNov
BOD, carbonaceous [5 day, 20 C]30-day average≤ 2018 lb/dAug
BOD, carbonaceous [5 day, 20 C]30-day average≤ 2018 lb/dMar
BOD, carbonaceous [5 day, 20 C]30-day average≤ 2018 lb/dJan
BOD, carbonaceous [5 day, 20 C]30-day average≤ 2018 lb/dJun
BOD, carbonaceous [5 day, 20 C]30-day average≤ 2018 lb/dJul
BOD, carbonaceous [5 day, 20 C]30-day average≤ 2018 lb/dSep
BOD, carbonaceous [5 day, 20 C]7-day average≤ 3027 lb/dOct
BOD, carbonaceous [5 day, 20 C]7-day average≤ 3027 lb/dDec
BOD, carbonaceous [5 day, 20 C]7-day average≤ 3027 lb/dFeb
BOD, carbonaceous [5 day, 20 C]7-day average≤ 3027 lb/dApr
BOD, carbonaceous [5 day, 20 C]7-day average≤ 3027 lb/dMay
BOD, carbonaceous [5 day, 20 C]7-day average≤ 3027 lb/dNov
BOD, carbonaceous [5 day, 20 C]daily maximum≤ 3027 lb/dAug
BOD, carbonaceous [5 day, 20 C]7-day average≤ 3027 lb/dMar
BOD, carbonaceous [5 day, 20 C]7-day average≤ 3027 lb/dJan
BOD, carbonaceous [5 day, 20 C]daily maximum≤ 3027 lb/dJun
BOD, carbonaceous [5 day, 20 C]daily maximum≤ 3027 lb/dJul
BOD, carbonaceous [5 day, 20 C]daily maximum≤ 3027 lb/dSep

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

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On EPA ECHO: Facility report · DMR history

Your permit document is the final word. As JSON: /api/v1/permits/IA0035955 · MCP: https://passage-data.com/mcp