CITY OF MARSHALLTOWN

NPDES permit IA0038610 · Major POTW · effective, expires 2027-10-31 · EPA's file as of 2026-09-19

Check this month's numbers before you file

EPA's record, 2025-09-01 to 2026-08-31

3values over a limit
0required values missing, on 0 form(s)
0of 12 forms filed late

Last period with anything received: 2026-08-31. Most often over: Solids, total suspended (3).

Reporting

Reports are due about 15 days after each monitoring period ends (the most common figure among IA permits in EPA's filings — check your permit).

Limits in force (66)

OutfallParameterStatisticLimitMonths
001Oxygen, dissolved [DO]DAILY MN >= 3.3 mg/L all year
001pHDAILY MN >= 6.1 SU all year
001pHDAILY MX <= 9 SU all year
001Solids, total suspended30DA AVG <= 30 mg/L all year
001Solids, total suspended7 DA AVG <= 45 mg/L all year
001Solids, total suspended30DA AVG <= 3263 lb/d all year
001Solids, total suspended7 DA AVG <= 4894 lb/d all year
001Nitrogen, ammonia total [as N]30DA AVG <= 12.5 mg/L Nov
001Nitrogen, ammonia total [as N]30DA AVG <= 10 mg/L Mar
001Nitrogen, ammonia total [as N]30DA AVG <= 6 mg/L May
001Nitrogen, ammonia total [as N]30DA AVG <= 4.5 mg/L Jul
001Nitrogen, ammonia total [as N]30DA AVG <= 14.8 mg/L Dec
001Nitrogen, ammonia total [as N]30DA AVG <= 4 mg/L Jun
001Nitrogen, ammonia total [as N]30DA AVG <= 19.8 mg/L Jan
001Nitrogen, ammonia total [as N]30DA AVG <= 22.4 mg/L Feb
001Nitrogen, ammonia total [as N]30DA AVG <= 10 mg/L Oct
001Nitrogen, ammonia total [as N]30DA AVG <= 7.1 mg/L Apr
001Nitrogen, ammonia total [as N]30DA AVG <= 4.6 mg/L Sep
001Nitrogen, ammonia total [as N]30DA AVG <= 4.1 mg/L Aug
001Nitrogen, ammonia total [as N]DAILY MX <= 29.2 mg/L Nov
001Nitrogen, ammonia total [as N]DAILY MX <= 35.4 mg/L Mar
001Nitrogen, ammonia total [as N]DAILY MX <= 26 mg/L May
001Nitrogen, ammonia total [as N]DAILY MX <= 13 mg/L Jul
001Nitrogen, ammonia total [as N]DAILY MX <= 32.8 mg/L Dec
001Nitrogen, ammonia total [as N]DAILY MX <= 16.6 mg/L Jun
001Nitrogen, ammonia total [as N]DAILY MX <= 38 mg/L Jan
001Nitrogen, ammonia total [as N]DAILY MX <= 40.8 mg/L Feb
001Nitrogen, ammonia total [as N]DAILY MX <= 32.4 mg/L Oct
001Nitrogen, ammonia total [as N]DAILY MX <= 30.5 mg/L Apr
001Nitrogen, ammonia total [as N]DAILY MX <= 15.2 mg/L Sep
001Nitrogen, ammonia total [as N]DAILY MX <= 14 mg/L Aug
001Nitrogen, ammonia total [as N]30DA AVG <= 856 lb/d Nov
001Nitrogen, ammonia total [as N]30DA AVG <= 688 lb/d Mar
001Nitrogen, ammonia total [as N]30DA AVG <= 422 lb/d May
001Nitrogen, ammonia total [as N]30DA AVG <= 298 lb/d Jul
001Nitrogen, ammonia total [as N]30DA AVG <= 1007 lb/d Dec
001Nitrogen, ammonia total [as N]30DA AVG <= 288 lb/d Jun
001Nitrogen, ammonia total [as N]30DA AVG <= 1342 lb/d Jan
001Nitrogen, ammonia total [as N]30DA AVG <= 1519 lb/d Feb
001Nitrogen, ammonia total [as N]30DA AVG <= 691 lb/d Oct
001Nitrogen, ammonia total [as N]30DA AVG <= 495 lb/d Apr
001Nitrogen, ammonia total [as N]30DA AVG <= 326 lb/d Sep
001Nitrogen, ammonia total [as N]30DA AVG <= 272 lb/d Aug
001Nitrogen, ammonia total [as N]DAILY MX <= 2397 lb/d Nov
001Nitrogen, ammonia total [as N]DAILY MX <= 2713 lb/d Mar
001Nitrogen, ammonia total [as N]DAILY MX <= 1718 lb/d May
001Nitrogen, ammonia total [as N]DAILY MX <= 892 lb/d Jul
001Nitrogen, ammonia total [as N]DAILY MX <= 2696.7 lb/d Dec
001Nitrogen, ammonia total [as N]DAILY MX <= 1131 lb/d Jun
001Nitrogen, ammonia total [as N]DAILY MX <= 2906 lb/d Jan
001Nitrogen, ammonia total [as N]DAILY MX <= 2983.3 lb/d Feb
001Nitrogen, ammonia total [as N]DAILY MX <= 2045 lb/d Oct
001Nitrogen, ammonia total [as N]DAILY MX <= 2528 lb/d Apr
001Nitrogen, ammonia total [as N]DAILY MX <= 1033 lb/d Sep
001Nitrogen, ammonia total [as N]DAILY MX <= 924 lb/d Aug
001Copper, total [as Cu]30DA AVG <= .04753 mg/L all year
001Copper, total [as Cu]DAILY MX <= .075 mg/L all year
001Copper, total [as Cu]30DA AVG <= 3.471 lb/d all year
001Copper, total [as Cu]DAILY MX <= 5.493 lb/d all year
001E. coliGEO MEAN <= 126 #/100mL Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov
001Toxicity [acute], Ceriodaphnia dubiaDAILY MX <= 1 N=0;Y=1 all year
001Toxicity [acute], Pimephales promelas [Fathead Minnow]DAILY MX <= 1 N=0;Y=1 all year
001BOD, carbonaceous [5 day, 20 C]30DA AVG <= 25 mg/L all year
001BOD, carbonaceous [5 day, 20 C]7 DA AVG <= 40 mg/L all year
001BOD, carbonaceous [5 day, 20 C]30DA AVG <= 2719 lb/d all year
001BOD, carbonaceous [5 day, 20 C]7 DA AVG <= 4350 lb/d all year

Built from EPA's ECHO bulk files. EPA's file, not the permit document, is the source: read your permit. Check a report before you file it · All states