City of Northwood — NPDES permit IA0032395: limits, due date and EPA's record

Sewage treatment plant, Northwood, Iowa. NPDES permit IA0032395, in force until Sep 30, 2029. Last 12 months: no values over a limit. Source: EPA ECHO, Oct 22, 2026.

Limits in force (134)

Parameter	Statistic	Limit	Months	Outfall
Oxygen, dissolved [DO]	daily minimum	≥ 1 mg/L	all year	001
BOD, 5-day, 20 deg. C	30-day average	report only (mg/L)	all year	001
BOD, 5-day, 20 deg. C	daily maximum	report only (mg/L)	all year	001
BOD, 5-day, 20 deg. C	30-day average	report only (lb/d)	all year	001
BOD, 5-day, 20 deg. C	daily maximum	report only (lb/d)	all year	001
pH	daily minimum	≥ 6 SU	all year	001
pH	daily maximum	≤ 9 SU	all year	001
pH	30-day average	report only (SU)	all year	001
pH	daily maximum	report only (SU)	all year	001
Solids, total suspended	30-day average	≤ 30 mg/L	all year	001
Solids, total suspended	7-day average	≤ 45 mg/L	all year	001
Solids, total suspended	30-day average	≤ 207 lb/d	all year	001
Solids, total suspended	7-day average	≤ 311 lb/d	all year	001
Solids, total suspended	30-day average	report only (mg/L)	all year	001
Solids, total suspended	daily maximum	report only (mg/L)	all year	001
Solids, total suspended	30-day average	report only (lb/d)	all year	001
Solids, total suspended	daily maximum	report only (lb/d)	all year	001
Nitrogen, ammonia total [as N]	30-day average	≤ 21.7 mg/L	Oct	001
Nitrogen, ammonia total [as N]	30-day average	≤ 49.7 mg/L	Feb	001
Nitrogen, ammonia total [as N]	30-day average	≤ 12 mg/L	Aug	001
Nitrogen, ammonia total [as N]	30-day average	≤ 16.8 mg/L	May	001
Nitrogen, ammonia total [as N]	30-day average	≤ 31.4 mg/L	Nov	001
Nitrogen, ammonia total [as N]	30-day average	≤ 13.2 mg/L	Jul	001
Nitrogen, ammonia total [as N]	30-day average	≤ 12.5 mg/L	Sep	001
Nitrogen, ammonia total [as N]	30-day average	≤ 45.1 mg/L	Jan	001
Nitrogen, ammonia total [as N]	30-day average	≤ 35.9 mg/L	Dec	001
Nitrogen, ammonia total [as N]	30-day average	≤ 20 mg/L	Apr	001
Nitrogen, ammonia total [as N]	30-day average	≤ 10.8 mg/L	Jun	001
Nitrogen, ammonia total [as N]	30-day average	≤ 26.4 mg/L	Mar	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 58.1 mg/L	Oct	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 85.6 mg/L	Feb	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 53 mg/L	Aug	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 65.4 mg/L	May	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 56.6 mg/L	Nov	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 48 mg/L	Jul	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 59.3 mg/L	Sep	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 75.5 mg/L	Jan	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 58.4 mg/L	Dec	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 58 mg/L	Apr	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 63 mg/L	Jun	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 73.9 mg/L	Mar	001
Nitrogen, ammonia total [as N]	30-day average	≤ 83.6 lb/d	Oct	001
Nitrogen, ammonia total [as N]	30-day average	≤ 179.7 lb/d	Feb	001
Nitrogen, ammonia total [as N]	30-day average	≤ 41.7 lb/d	Aug	001
Nitrogen, ammonia total [as N]	30-day average	≤ 59.8 lb/d	May	001
Nitrogen, ammonia total [as N]	30-day average	≤ 117.6 lb/d	Nov	001
Nitrogen, ammonia total [as N]	30-day average	≤ 45.7 lb/d	Jul	001
Nitrogen, ammonia total [as N]	30-day average	≤ 45 lb/d	Sep	001
Nitrogen, ammonia total [as N]	30-day average	≤ 167.8 lb/d	Jan	001
Nitrogen, ammonia total [as N]	30-day average	≤ 142.9 lb/d	Dec	001
Nitrogen, ammonia total [as N]	30-day average	≤ 71 lb/d	Apr	001
Nitrogen, ammonia total [as N]	30-day average	≤ 39.2 lb/d	Jun	001
Nitrogen, ammonia total [as N]	30-day average	≤ 98.5 lb/d	Mar	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 249.1 lb/d	Oct	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 325.3 lb/d	Feb	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 150.7 lb/d	Aug	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 268.6 lb/d	May	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 239.3 lb/d	Nov	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 132.7 lb/d	Jul	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 215.7 lb/d	Sep	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 299 lb/d	Jan	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 251.4 lb/d	Dec	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 248.8 lb/d	Apr	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 181.1 lb/d	Jun	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 291.8 lb/d	Mar	001
Nitrogen, Kjeldahl, total [as N]	30-day average	report only (mg/L)	all year	001
Nitrogen, Kjeldahl, total [as N]	daily maximum	report only (mg/L)	all year	001
Nitrogen, Kjeldahl, total [as N]	30-day average	report only (lb/d)	all year	001
Nitrogen, Kjeldahl, total [as N]	daily maximum	report only (lb/d)	all year	001
E. coli	geometric mean	≤ 126 #/100mL	Mar–Nov	001
BOD, carbonaceous [5 day, 20 C]	30-day average	≤ 25 mg/L	all year	001
BOD, carbonaceous [5 day, 20 C]	7-day average	≤ 40 mg/L	all year	001
BOD, carbonaceous [5 day, 20 C]	30-day average	≤ 173 lb/d	all year	001
BOD, carbonaceous [5 day, 20 C]	7-day average	≤ 277 lb/d	all year	001
Oxygen, dissolved [DO]	daily minimum	≥ 1 mg/L	all year	002
pH	daily minimum	≥ 6.3 SU	all year	002
pH	daily maximum	≤ 9 SU	all year	002
Solids, total suspended	30-day average	≤ 30 mg/L	all year	002
Solids, total suspended	7-day average	≤ 45 mg/L	all year	002
Solids, total suspended	30-day average	≤ 207 lb/d	all year	002
Solids, total suspended	7-day average	≤ 311 lb/d	all year	002
Nitrogen, ammonia total [as N]	30-day average	≤ 3.6 mg/L	Aug	002
Nitrogen, ammonia total [as N]	30-day average	≤ 12.9 mg/L	Jan	002
Nitrogen, ammonia total [as N]	30-day average	≤ 14.8 mg/L	Feb	002
Nitrogen, ammonia total [as N]	30-day average	≤ 5.6 mg/L	May	002
Nitrogen, ammonia total [as N]	30-day average	≤ 8.8 mg/L	Nov	002
Nitrogen, ammonia total [as N]	30-day average	≤ 5.9 mg/L	Oct	002
Nitrogen, ammonia total [as N]	30-day average	≤ 9.3 mg/L	Dec	002
Nitrogen, ammonia total [as N]	30-day average	≤ 5.7 mg/L	Apr	002
Nitrogen, ammonia total [as N]	30-day average	≤ 3.7 mg/L	Jun	002
Nitrogen, ammonia total [as N]	30-day average	≤ 4 mg/L	Sep	002
Nitrogen, ammonia total [as N]	30-day average	≤ 7.6 mg/L	Mar	002
Nitrogen, ammonia total [as N]	30-day average	≤ 3.8 mg/L	Jul	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 17.8 mg/L	Aug	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 16.9 mg/L	Jan	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 16.1 mg/L	Feb	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 16.7 mg/L	May	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 16 mg/L	Nov	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 17.1 mg/L	Oct	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 17.4 mg/L	Dec	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 17.1 mg/L	Apr	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 15.9 mg/L	Jun	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 18 mg/L	Sep	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 16.3 mg/L	Mar	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 19.3 mg/L	Jul	002
Nitrogen, ammonia total [as N]	30-day average	≤ 15.5 lb/d	Aug	002
Nitrogen, ammonia total [as N]	30-day average	≤ 77 lb/d	Jan	002
Nitrogen, ammonia total [as N]	30-day average	≤ 87.1 lb/d	Feb	002
Nitrogen, ammonia total [as N]	30-day average	≤ 24.5 lb/d	May	002
Nitrogen, ammonia total [as N]	30-day average	≤ 49.2 lb/d	Nov	002
Nitrogen, ammonia total [as N]	30-day average	≤ 37.9 lb/d	Oct	002
Nitrogen, ammonia total [as N]	30-day average	≤ 57.8 lb/d	Dec	002
Nitrogen, ammonia total [as N]	30-day average	≤ 28.6 lb/d	Apr	002
Nitrogen, ammonia total [as N]	30-day average	≤ 16.8 lb/d	Jun	002
Nitrogen, ammonia total [as N]	30-day average	≤ 18.9 lb/d	Sep	002
Nitrogen, ammonia total [as N]	30-day average	≤ 39.7 lb/d	Mar	002
Nitrogen, ammonia total [as N]	30-day average	≤ 17 lb/d	Jul	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 117.3 lb/d	Aug	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 112.9 lb/d	Jan	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 107.5 lb/d	Feb	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 110.1 lb/d	May	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 106.6 lb/d	Nov	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 114.5 lb/d	Oct	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 116.4 lb/d	Dec	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 113.8 lb/d	Apr	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 104.8 lb/d	Jun	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 120.1 lb/d	Sep	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 108.3 lb/d	Mar	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 127.6 lb/d	Jul	002
E. coli	geometric mean	≤ 126 #/100mL	Mar–Nov	002
BOD, carbonaceous [5 day, 20 C]	30-day average	≤ 25 mg/L	all year	002
BOD, carbonaceous [5 day, 20 C]	7-day average	≤ 40 mg/L	all year	002
BOD, carbonaceous [5 day, 20 C]	30-day average	≤ 173 lb/d	all year	002
BOD, carbonaceous [5 day, 20 C]	7-day average	≤ 277 lb/d	all year	002

How strict are these limits?

Your permit document is the final word. As JSON: /api/v1/permits/IA0032395 · MCP: https://passage-data.com/mcp