CITY OF GRINNELL

NPDES permit IA0031186 · Major POTW · effective, expires 2029-11-30 · 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

0values over a limit
0required values missing, on 0 form(s)
0of 11 forms filed late

Last period with anything received: 2026-07-31.

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 (84)

OutfallParameterStatisticLimitMonths
001Oxygen, dissolved [DO]DAILY MN >= 5 mg/L all year
001BOD, 5-day, 20 deg. C30DA AVG report only all year
001BOD, 5-day, 20 deg. CDAILY MX report only all year
001BOD, 5-day, 20 deg. C30DA AVG report only all year
001BOD, 5-day, 20 deg. CDAILY MX report only all year
001pHDAILY MN >= 6.5 SU all year
001pHDAILY MX <= 9 SU all year
001pH30DA AVG report only all year
001pHDAILY MX report only 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 <= 1060 lb/d all year
001Solids, total suspended7 DA AVG <= 1590 lb/d all year
001Solids, total suspended30DA AVG report only all year
001Solids, total suspendedDAILY MX report only all year
001Solids, total suspended30DA AVG report only all year
001Solids, total suspendedDAILY MX report only all year
001Nitrogen, total [as N]30DA AVG report only all year
001Nitrogen, total [as N]DAILY MX report only all year
001Nitrogen, total [as N]30DA AVG report only all year
001Nitrogen, total [as N]DAILY MX report only all year
001Nitrogen, ammonia total [as N]30DA AVG <= 1.5 mg/L Apr
001Nitrogen, ammonia total [as N]30DA AVG <= 1 mg/L Jul
001Nitrogen, ammonia total [as N]30DA AVG <= 1.1 mg/L Sep
001Nitrogen, ammonia total [as N]30DA AVG <= 1.7 mg/L May
001Nitrogen, ammonia total [as N]30DA AVG <= 4 mg/L Feb
001Nitrogen, ammonia total [as N]30DA AVG <= 3.4 mg/L Mar
001Nitrogen, ammonia total [as N]30DA AVG <= 2.3 mg/L Nov
001Nitrogen, ammonia total [as N]30DA AVG <= 2.5 mg/L Dec
001Nitrogen, ammonia total [as N]30DA AVG <= 3.4 mg/L Jan
001Nitrogen, ammonia total [as N]30DA AVG <= 1 mg/L Aug
001Nitrogen, ammonia total [as N]30DA AVG <= 1.3 mg/L Jun
001Nitrogen, ammonia total [as N]30DA AVG <= 1.6 mg/L Oct
001Nitrogen, ammonia total [as N]DAILY MX <= 15.7 mg/L Apr
001Nitrogen, ammonia total [as N]DAILY MX <= 17.6 mg/L Jul
001Nitrogen, ammonia total [as N]DAILY MX <= 16.5 mg/L Sep
001Nitrogen, ammonia total [as N]DAILY MX <= 15.2 mg/L May
001Nitrogen, ammonia total [as N]DAILY MX <= 14.2 mg/L Feb
001Nitrogen, ammonia total [as N]DAILY MX <= 14.7 mg/L Mar
001Nitrogen, ammonia total [as N]DAILY MX <= 14.7 mg/L Nov
001Nitrogen, ammonia total [as N]DAILY MX <= 16 mg/L Dec
001Nitrogen, ammonia total [as N]DAILY MX <= 15.2 mg/L Jan
001Nitrogen, ammonia total [as N]DAILY MX <= 16.2 mg/L Aug
001Nitrogen, ammonia total [as N]DAILY MX <= 14.4 mg/L Jun
001Nitrogen, ammonia total [as N]DAILY MX <= 15.7 mg/L Oct
001Nitrogen, ammonia total [as N]30DA AVG <= 53.8 lb/d Apr
001Nitrogen, ammonia total [as N]30DA AVG <= 35.5 lb/d Jul
001Nitrogen, ammonia total [as N]30DA AVG <= 37.3 lb/d Sep
001Nitrogen, ammonia total [as N]30DA AVG <= 61.4 lb/d May
001Nitrogen, ammonia total [as N]30DA AVG <= 139.6 lb/d Feb
001Nitrogen, ammonia total [as N]30DA AVG <= 120.3 lb/d Mar
001Nitrogen, ammonia total [as N]30DA AVG <= 82 lb/d Nov
001Nitrogen, ammonia total [as N]30DA AVG <= 87.4 lb/d Dec
001Nitrogen, ammonia total [as N]30DA AVG <= 120.3 lb/d Jan
001Nitrogen, ammonia total [as N]30DA AVG <= 33.7 lb/d Aug
001Nitrogen, ammonia total [as N]30DA AVG <= 46.2 lb/d Jun
001Nitrogen, ammonia total [as N]30DA AVG <= 55 lb/d Oct
001Nitrogen, ammonia total [as N]DAILY MX <= 554.7 lb/d Apr
001Nitrogen, ammonia total [as N]DAILY MX <= 621.2 lb/d Jul
001Nitrogen, ammonia total [as N]DAILY MX <= 582.6 lb/d Sep
001Nitrogen, ammonia total [as N]DAILY MX <= 536.6 lb/d May
001Nitrogen, ammonia total [as N]DAILY MX <= 501.6 lb/d Feb
001Nitrogen, ammonia total [as N]DAILY MX <= 518.9 lb/d Mar
001Nitrogen, ammonia total [as N]DAILY MX <= 518.9 lb/d Nov
001Nitrogen, ammonia total [as N]DAILY MX <= 563.9 lb/d Dec
001Nitrogen, ammonia total [as N]DAILY MX <= 536.6 lb/d Jan
001Nitrogen, ammonia total [as N]DAILY MX <= 573.2 lb/d Aug
001Nitrogen, ammonia total [as N]DAILY MX <= 510.2 lb/d Jun
001Nitrogen, ammonia total [as N]DAILY MX <= 554.7 lb/d Oct
001Nitrogen, Kjeldahl, total [as N]30DA AVG report only all year
001Nitrogen, Kjeldahl, total [as N]DAILY MX report only all year
001Nitrogen, Kjeldahl, total [as N]30DA AVG report only all year
001Nitrogen, Kjeldahl, total [as N]DAILY MX report only all year
001Phosphorus, total [as P]30DA AVG report only all year
001Phosphorus, total [as P]DAILY MX report only all year
001Phosphorus, total [as P]30DA AVG report only all year
001Phosphorus, total [as P]DAILY MX report only all year
001E. coliGEO MEAN <= 630 #/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 <= 883 lb/d all year
001BOD, carbonaceous [5 day, 20 C]7 DA AVG <= 1413 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