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

City of Onslow

Sewage treatment plant, Onslow, Iowa. NPDES permit IA0057134, in force until Oct 31, 2029. 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 (11 values)
Last report on file
August 2026
Oct 2024 – Sep 2025
0 values over a limit, 0 required values missing, 0 of 12 reports late

Limits in force (55)

ParameterStatisticLimitMonths
pHdaily minimum≥ 6 SUall year
pHdaily maximum≤ 9 SUall year
Solids, total suspended30-day average≤ 80 mg/Lall year
Solids, total suspended7-day average≤ 120 mg/Lall year
Nitrogen, ammonia total [as N]30-day average≤ 3.7 mg/LMar
Nitrogen, ammonia total [as N]30-day average≤ 2.7 mg/LDec
Nitrogen, ammonia total [as N]30-day average≤ 1.2 mg/LSep
Nitrogen, ammonia total [as N]30-day average≤ 1.5 mg/LJun
Nitrogen, ammonia total [as N]30-day average≤ 1.1 mg/LJul
Nitrogen, ammonia total [as N]30-day average≤ 2.5 mg/LNov
Nitrogen, ammonia total [as N]30-day average≤ 4.2 mg/LFeb
Nitrogen, ammonia total [as N]30-day average≤ 1.1 mg/LAug
Nitrogen, ammonia total [as N]30-day average≤ 3.7 mg/LJan
Nitrogen, ammonia total [as N]30-day average≤ 1.7 mg/LApr
Nitrogen, ammonia total [as N]30-day average≤ 1.7 mg/LOct
Nitrogen, ammonia total [as N]30-day average≤ 1.9 mg/LMay
Nitrogen, ammonia total [as N]daily maximum≤ 3.9 mg/LMar
Nitrogen, ammonia total [as N]daily maximum≤ 3.9 mg/LDec
Nitrogen, ammonia total [as N]daily maximum≤ 2.7 mg/LSep
Nitrogen, ammonia total [as N]daily maximum≤ 3.3 mg/LJun
Nitrogen, ammonia total [as N]daily maximum≤ 3.3 mg/LJul
Nitrogen, ammonia total [as N]daily maximum≤ 2.7 mg/LNov
Nitrogen, ammonia total [as N]daily maximum≤ 8.5 mg/LFeb
Nitrogen, ammonia total [as N]daily maximum≤ 2.8 mg/LAug
Nitrogen, ammonia total [as N]daily maximum≤ 13.7 mg/LJan
Nitrogen, ammonia total [as N]daily maximum≤ 4.8 mg/LApr
Nitrogen, ammonia total [as N]daily maximum≤ 2.7 mg/LOct
Nitrogen, ammonia total [as N]daily maximum≤ 3.3 mg/LMay
Nitrogen, ammonia total [as N]30-day average≤ 15.3 lb/dMar
Nitrogen, ammonia total [as N]30-day average≤ 13.3 lb/dDec
Nitrogen, ammonia total [as N]30-day average≤ 5.2 lb/dSep
Nitrogen, ammonia total [as N]30-day average≤ 4.7 lb/dJun
Nitrogen, ammonia total [as N]30-day average≤ 4.1 lb/dJul
Nitrogen, ammonia total [as N]30-day average≤ 11.5 lb/dNov
Nitrogen, ammonia total [as N]30-day average≤ 19.6 lb/dFeb
Nitrogen, ammonia total [as N]30-day average≤ 3.7 lb/dAug
Nitrogen, ammonia total [as N]30-day average≤ 17.2 lb/dJan
Nitrogen, ammonia total [as N]30-day average≤ 7.1 lb/dApr
Nitrogen, ammonia total [as N]30-day average≤ 9.7 lb/dOct
Nitrogen, ammonia total [as N]30-day average≤ 6.3 lb/dMay
Nitrogen, ammonia total [as N]daily maximum≤ 29 lb/dMar
Nitrogen, ammonia total [as N]daily maximum≤ 27.5 lb/dDec
Nitrogen, ammonia total [as N]daily maximum≤ 19.8 lb/dSep
Nitrogen, ammonia total [as N]daily maximum≤ 24 lb/dJun
Nitrogen, ammonia total [as N]daily maximum≤ 24 lb/dJul
Nitrogen, ammonia total [as N]daily maximum≤ 19.8 lb/dNov
Nitrogen, ammonia total [as N]daily maximum≤ 47.3 lb/dFeb
Nitrogen, ammonia total [as N]daily maximum≤ 19.8 lb/dAug
Nitrogen, ammonia total [as N]daily maximum≤ 39.4 lb/dJan
Nitrogen, ammonia total [as N]daily maximum≤ 23.2 lb/dApr
Nitrogen, ammonia total [as N]daily maximum≤ 19.8 lb/dOct
Nitrogen, ammonia total [as N]daily maximum≤ 23.7 lb/dMay
E. coligeometric mean≤ 229 #/100mLMar–Nov
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

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/IA0057134 · MCP: https://passage-data.com/mcp