INTERSTATE POWER & LIGHT COMPANY

NPDES permit IA0053720 · Minor NON-POTW · effective, expires 2031-03-31 · 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

0values over a limit
0required values missing, on 0 form(s)
0of 5 forms filed late

Last period with anything received: 2026-08-31.

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 (10)

OutfallParameterStatisticLimitMonths
001pHDAILY MN >= 6 SU all year
001pHDAILY MX <= 9 SU all year
001Sulfate, total [as SO4]30DA AVG <= 1514 mg/L all year
001Sulfate, total [as SO4]DAILY MX <= 1514 mg/L all year
001Sulfate, total [as SO4]30DA AVG <= 1060 lb/d all year
001Sulfate, total [as SO4]DAILY MX <= 1060 lb/d all year
001Iron, total [as Fe]30DA AVG <= 3.7 mg/L all year
001Iron, total [as Fe]DAILY MX <= 3.7 mg/L all year
001Iron, total [as Fe]30DA AVG <= 2.59 lb/d all year
001Iron, total [as Fe]DAILY MX <= 2.59 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