City of Webster City — NPDES permit IA0036625: limits, due date and EPA's record

Sewage treatment plant, major discharger, Webster City, Iowa. NPDES permit IA0036625 expired Sep 30, 2026; its limits still apply. Last 12 months: over a limit 7 times (last August 2026). Source: EPA ECHO, Oct 22, 2026.

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

Period ending	Parameter	Reported	Limit	Over by
December 2025	Copper, total [as Cu], 30-day average	.023	≤ .01687 mg/L	36%
January 2026	Solids, total suspended, 30-day average	34.75	≤ 30 mg/L	16%
January 2026	Solids, total suspended, 7-day average	82	≤ 45 mg/L	82%
February 2026	Copper, total [as Cu], 30-day average	.017	≤ .01687 mg/L	1%
May 2026	Copper, total [as Cu], 30-day average	.019	≤ .01687 mg/L	13%
June 2026	Copper, total [as Cu], 30-day average	.017	≤ .01687 mg/L	1%
August 2026	Nitrogen, ammonia total [as N], 30-day average	1.135	≤ 1 mg/L	14%

Limits in force (186)

Parameter	Statistic	Limit	Months	Outfall
Oxygen, dissolved [DO]	daily minimum	≥ 5 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	≥ 6.5 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	≤ 826 lb/d	all year	001
Solids, total suspended	7-day average	≤ 1238 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, total [as N]	30-day average	report only (mg/L)	all year	001
Nitrogen, total [as N]	daily maximum	report only (mg/L)	all year	001
Nitrogen, total [as N]	30-day average	report only (lb/d)	all year	001
Nitrogen, total [as N]	daily maximum	report only (lb/d)	all year	001
Nitrogen, total [as N]	30-day average	report only (mg/L)	all year	001
Nitrogen, total [as N]	daily maximum	report only (mg/L)	all year	001
Nitrogen, total [as N]	30-day average	report only (lb/d)	all year	001
Nitrogen, total [as N]	daily maximum	report only (lb/d)	all year	001
Nitrogen, ammonia total [as N]	30-day average	≤ 1.1 mg/L	Sep	001
Nitrogen, ammonia total [as N]	30-day average	≤ 1.6 mg/L	Oct	001
Nitrogen, ammonia total [as N]	30-day average	≤ 1 mg/L	Jul	001
Nitrogen, ammonia total [as N]	30-day average	≤ 3.4 mg/L	Jan	001
Nitrogen, ammonia total [as N]	30-day average	≤ 1 mg/L	Aug	001
Nitrogen, ammonia total [as N]	30-day average	≤ 2.3 mg/L	Nov	001
Nitrogen, ammonia total [as N]	30-day average	≤ 3.4 mg/L	Mar	001
Nitrogen, ammonia total [as N]	30-day average	≤ 1.5 mg/L	Apr	001
Nitrogen, ammonia total [as N]	30-day average	≤ 1.3 mg/L	Jun	001
Nitrogen, ammonia total [as N]	30-day average	≤ 2.5 mg/L	Dec	001
Nitrogen, ammonia total [as N]	30-day average	≤ 4 mg/L	Feb	001
Nitrogen, ammonia total [as N]	30-day average	≤ 1.7 mg/L	May	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 16.5 mg/L	Sep	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 15.7 mg/L	Oct	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 17.6 mg/L	Jul	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 15.2 mg/L	Jan	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 16.2 mg/L	Aug	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 14.7 mg/L	Nov	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 14.7 mg/L	Mar	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 15.7 mg/L	Apr	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 14.4 mg/L	Jun	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 16 mg/L	Dec	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 14.2 mg/L	Feb	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 15.2 mg/L	May	001
Nitrogen, ammonia total [as N]	30-day average	≤ 29 lb/d	Sep	001
Nitrogen, ammonia total [as N]	30-day average	≤ 43 lb/d	Oct	001
Nitrogen, ammonia total [as N]	30-day average	≤ 28 lb/d	Jul	001
Nitrogen, ammonia total [as N]	30-day average	≤ 94 lb/d	Jan	001
Nitrogen, ammonia total [as N]	30-day average	≤ 26 lb/d	Aug	001
Nitrogen, ammonia total [as N]	30-day average	≤ 64 lb/d	Nov	001
Nitrogen, ammonia total [as N]	30-day average	≤ 94 lb/d	Mar	001
Nitrogen, ammonia total [as N]	30-day average	≤ 42 lb/d	Apr	001
Nitrogen, ammonia total [as N]	30-day average	≤ 36 lb/d	Jun	001
Nitrogen, ammonia total [as N]	30-day average	≤ 68 lb/d	Dec	001
Nitrogen, ammonia total [as N]	30-day average	≤ 109 lb/d	Feb	001
Nitrogen, ammonia total [as N]	30-day average	≤ 48 lb/d	May	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 454 lb/d	Sep	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 432 lb/d	Oct	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 484 lb/d	Jul	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 418 lb/d	Jan	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 447 lb/d	Aug	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 404 lb/d	Nov	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 404 lb/d	Mar	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 432 lb/d	Apr	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 397 lb/d	Jun	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 439 lb/d	Dec	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 391 lb/d	Feb	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 418 lb/d	May	001
Nitrogen, nitrate total [as N]	30-day average	≤ 760 lb/d	all year	001
Nitrogen, nitrate total [as N]	daily maximum	≤ 1244 lb/d	all year	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
Phosphorus, total [as P]	30-day average	report only (mg/L)	all year	001
Phosphorus, total [as P]	daily maximum	report only (mg/L)	all year	001
Phosphorus, total [as P]	30-day average	report only (lb/d)	all year	001
Phosphorus, total [as P]	daily maximum	report only (lb/d)	all year	001
Phosphorus, total [as P]	30-day average	report only (mg/L)	all year	001
Phosphorus, total [as P]	daily maximum	report only (mg/L)	all year	001
Phosphorus, total [as P]	30-day average	report only (lb/d)	all year	001
Phosphorus, total [as P]	daily maximum	report only (lb/d)	all year	001
Chloride [as Cl]	30-day average	report only (mg/L)	all year	001
Chloride [as Cl]	daily maximum	report only (mg/L)	all year	001
Chloride [as Cl]	30-day average	report only (lb/d)	all year	001
Chloride [as Cl]	daily maximum	report only (lb/d)	all year	001
Cadmium, total [as Cd]	30-day average	≤ .0004523 mg/L	all year	001
Cadmium, total [as Cd]	daily maximum	≤ .004316 mg/L	all year	001
Cadmium, total [as Cd]	30-day average	≤ .01245 lb/d	all year	001
Cadmium, total [as Cd]	daily maximum	≤ .1188 lb/d	all year	001
Copper, total [as Cu]	30-day average	≤ .01687 mg/L	all year	001
Copper, total [as Cu]	daily maximum	≤ .0269 mg/L	all year	001
Copper, total [as Cu]	30-day average	≤ .4642 lb/d	all year	001
Copper, total [as Cu]	daily maximum	≤ .7403 lb/d	all year	001
Chlorine, total residual	30-day average	≤ .008 mg/L	all year	001
Chlorine, total residual	daily maximum	≤ .019 mg/L	all year	001
Chlorine, total residual	30-day average	≤ .216 lb/d	all year	001
Chlorine, total residual	daily maximum	≤ .523 lb/d	all year	001
E. coli	geometric mean	≤ 630 #/100mL	Mar–Nov	001
Toxicity [acute], Ceriodaphnia dubia	daily maximum	≤ 1 N=0;Y=1	all year	001
Toxicity [acute], Pimephales promelas [Fathead Minnow]	daily maximum	≤ 1 N=0;Y=1	all year	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	≤ 688 lb/d	all year	001
BOD, carbonaceous [5 day, 20 C]	7-day average	≤ 1101 lb/d	all year	001
Oxygen, dissolved [DO]	daily minimum	≥ 4.3 mg/L	all year	003
pH	daily minimum	≥ 6.5 SU	all year	003
pH	daily maximum	≤ 9 SU	all year	003
Solids, total suspended	30-day average	≤ 30 mg/L	all year	003
Solids, total suspended	7-day average	≤ 45 mg/L	all year	003
Solids, total suspended	30-day average	≤ 826 lb/d	all year	003
Solids, total suspended	7-day average	≤ 1238 lb/d	all year	003
Nitrogen, ammonia total [as N]	30-day average	≤ 9.4 mg/L	Feb	003
Nitrogen, ammonia total [as N]	30-day average	≤ 2.5 mg/L	Sep	003
Nitrogen, ammonia total [as N]	30-day average	≤ 8.2 mg/L	Jan	003
Nitrogen, ammonia total [as N]	30-day average	≤ 3.6 mg/L	Apr	003
Nitrogen, ammonia total [as N]	30-day average	≤ 2.2 mg/L	Jul	003
Nitrogen, ammonia total [as N]	30-day average	≤ 2 mg/L	Aug	003
Nitrogen, ammonia total [as N]	30-day average	≤ 4.9 mg/L	Mar	003
Nitrogen, ammonia total [as N]	30-day average	≤ 3.2 mg/L	May	003
Nitrogen, ammonia total [as N]	30-day average	≤ 3.7 mg/L	Oct	003
Nitrogen, ammonia total [as N]	30-day average	≤ 5.6 mg/L	Nov	003
Nitrogen, ammonia total [as N]	30-day average	≤ 2.2 mg/L	Jun	003
Nitrogen, ammonia total [as N]	30-day average	≤ 5.9 mg/L	Dec	003
Nitrogen, ammonia total [as N]	daily maximum	≤ 15.2 mg/L	Feb	003
Nitrogen, ammonia total [as N]	daily maximum	≤ 14.5 mg/L	Sep	003
Nitrogen, ammonia total [as N]	daily maximum	≤ 16.1 mg/L	Jan	003
Nitrogen, ammonia total [as N]	daily maximum	≤ 16.3 mg/L	Apr	003
Nitrogen, ammonia total [as N]	daily maximum	≤ 12.2 mg/L	Jul	003
Nitrogen, ammonia total [as N]	daily maximum	≤ 12.9 mg/L	Aug	003
Nitrogen, ammonia total [as N]	daily maximum	≤ 15.4 mg/L	Mar	003
Nitrogen, ammonia total [as N]	daily maximum	≤ 15.8 mg/L	May	003
Nitrogen, ammonia total [as N]	daily maximum	≤ 16.4 mg/L	Oct	003
Nitrogen, ammonia total [as N]	daily maximum	≤ 15.2 mg/L	Nov	003
Nitrogen, ammonia total [as N]	daily maximum	≤ 15 mg/L	Jun	003
Nitrogen, ammonia total [as N]	daily maximum	≤ 16.6 mg/L	Dec	003
Nitrogen, ammonia total [as N]	30-day average	≤ 246 lb/d	Feb	003
Nitrogen, ammonia total [as N]	30-day average	≤ 66 lb/d	Sep	003
Nitrogen, ammonia total [as N]	30-day average	≤ 214 lb/d	Jan	003
Nitrogen, ammonia total [as N]	30-day average	≤ 95 lb/d	Apr	003
Nitrogen, ammonia total [as N]	30-day average	≤ 58 lb/d	Jul	003
Nitrogen, ammonia total [as N]	30-day average	≤ 53 lb/d	Aug	003
Nitrogen, ammonia total [as N]	30-day average	≤ 128 lb/d	Mar	003
Nitrogen, ammonia total [as N]	30-day average	≤ 86 lb/d	May	003
Nitrogen, ammonia total [as N]	30-day average	≤ 97 lb/d	Oct	003
Nitrogen, ammonia total [as N]	30-day average	≤ 146 lb/d	Nov	003
Nitrogen, ammonia total [as N]	30-day average	≤ 59 lb/d	Jun	003
Nitrogen, ammonia total [as N]	30-day average	≤ 155 lb/d	Dec	003
Nitrogen, ammonia total [as N]	daily maximum	≤ 403 lb/d	Feb	003
Nitrogen, ammonia total [as N]	daily maximum	≤ 215 lb/d	Sep	003
Nitrogen, ammonia total [as N]	daily maximum	≤ 429 lb/d	Jan	003
Nitrogen, ammonia total [as N]	daily maximum	≤ 439 lb/d	Apr	003
Nitrogen, ammonia total [as N]	daily maximum	≤ 179 lb/d	Jul	003
Nitrogen, ammonia total [as N]	daily maximum	≤ 184 lb/d	Aug	003
Nitrogen, ammonia total [as N]	daily maximum	≤ 413 lb/d	Mar	003
Nitrogen, ammonia total [as N]	daily maximum	≤ 359 lb/d	May	003
Nitrogen, ammonia total [as N]	daily maximum	≤ 418 lb/d	Oct	003
Nitrogen, ammonia total [as N]	daily maximum	≤ 411 lb/d	Nov	003
Nitrogen, ammonia total [as N]	daily maximum	≤ 234 lb/d	Jun	003
Nitrogen, ammonia total [as N]	daily maximum	≤ 448 lb/d	Dec	003
Nitrogen, nitrate total [as N]	30-day average	≤ 760 lb/d	all year	003
Nitrogen, nitrate total [as N]	daily maximum	≤ 1244 lb/d	all year	003
Cadmium, total [as Cd]	30-day average	≤ .0006277 mg/L	all year	003
Cadmium, total [as Cd]	daily maximum	≤ .004474 mg/L	all year	003
Cadmium, total [as Cd]	30-day average	≤ .01464 lb/d	all year	003
Cadmium, total [as Cd]	daily maximum	≤ .1208 lb/d	all year	003
Copper, total [as Cu]	30-day average	≤ .02177 mg/L	all year	003
Copper, total [as Cu]	daily maximum	≤ .02773 mg/L	all year	003
Copper, total [as Cu]	30-day average	≤ .5256 lb/d	all year	003
Copper, total [as Cu]	daily maximum	≤ .7507 lb/d	all year	003
Chlorine, total residual	30-day average	≤ .012 mg/L	all year	003
Chlorine, total residual	daily maximum	≤ .02 mg/L	all year	003
Chlorine, total residual	30-day average	≤ .274 lb/d	all year	003
Chlorine, total residual	daily maximum	≤ .536 lb/d	all year	003
E. coli	geometric mean	≤ 126 #/100mL	Mar–Nov	003
Toxicity [acute], Ceriodaphnia dubia	daily maximum	≤ 1 N=0;Y=1	all year	003
Toxicity [acute], Pimephales promelas [Fathead Minnow]	daily maximum	≤ 1 N=0;Y=1	all year	003
BOD, carbonaceous [5 day, 20 C]	30-day average	≤ 25 mg/L	all year	003
BOD, carbonaceous [5 day, 20 C]	7-day average	≤ 40 mg/L	all year	003
BOD, carbonaceous [5 day, 20 C]	30-day average	≤ 688 lb/d	all year	003
BOD, carbonaceous [5 day, 20 C]	7-day average	≤ 1101 lb/d	all year	003

How strict are these limits?

Your permit document is the final word. As JSON: /api/v1/permits/IA0036625 · MCP: https://passage-data.com/mcp