Northfield city of

NPDES permit MN0024368 · Major POTW · expired, expires 2025-05-31 · EPA's file as of 2026-09-19

Check this month's numbers before you file

This permit expired on 2025-05-31 and is expired: its last limits keep applying until a new permit is issued, and EPA still expects the reports.

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

0values over a limit
0required values missing, on 0 form(s)
0of 36 forms filed late

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

Reporting

Reports are due about 21 days after each monitoring period ends (the most common figure among MN permits in EPA's filings — check your permit).

Limits in force (53)

OutfallParameterStatisticLimitMonths
D052Oxygen, dissolved [DO]MO MIN report only all year
D052pHMO MIN >= 6 SU all year
D052pHMO MAX <= 9 SU all year
D052Solids, total suspendedMO AVG <= 30 mg/L all year
D052Solids, total suspendedMO MAX report only May, Sep
D052Solids, total suspendedMX WK AV <= 45 mg/L all year
D052Solids, total suspendedMO AVG <= 386 kg/d all year
D052Solids, total suspendedMX WK AV <= 578 kg/d all year
D052Nitrogen, total [as N]MO AVG report only all year
D052Nitrogen, ammonia total [as N]MO AVG <= 34 mg/L Oct, Nov
D052Nitrogen, ammonia total [as N]MO AVG <= 20 mg/L Apr, May
D052Nitrogen, ammonia total [as N]MO AVG <= 8.9 mg/L Jun, Jul, Aug, Sep
D052Nitrogen, ammonia total [as N]MO AVG report only Jan, Feb, Mar, Dec
D052Nitrogen, ammonia total [as N]MO AVG <= 668 kg/d Oct, Nov
D052Nitrogen, ammonia total [as N]MO AVG <= 393 kg/d Apr, May
D052Nitrogen, ammonia total [as N]MO AVG <= 175 kg/d Jun, Jul, Aug, Sep
D052Nitrogen, ammonia total [as N]MO AVG report only Jan, Feb, Mar, Dec
D052Nitrogen, Kjeldahl, total [as N]MO AVG report only all year
D052Nitrite + Nitrate total [as N]MO AVG report only all year
D052Phosphorus, total [as P]MO AVG <= 1 mg/L Jun, Jul, Aug, Sep
D052Phosphorus, total [as P]MO AVG <= 1 mg/L Jan, Feb, Mar, Apr, May, Oct, Nov, Dec
D052Phosphorus, total [as P]MO AVG <= 24.8 kg/d Jun, Jul, Aug, Sep
D052Phosphorus, total [as P]MO AVG report only Jan, Feb, Mar, Apr, May, Oct, Nov, Dec
D052Phosphorus, total [as P]ANNL TOT <= 6223 kg/yr all year
D052Copper, total [as Cu]DAILY MX <= 113 ug/L all year
D052Copper, total [as Cu]DAILY MX <= 1.45 kg/d all year
D052Coliform, fecal MPN + membrane ftl 44.5 CMO GEOMN <= 200 #/100mL Apr, May, Jun, Jul, Aug, Sep, Oct
D052Flow, in conduit or thru treatment plantMO AVG report only all year
D052Flow, in conduit or thru treatment plantMO MAX report only all year
D052Flow, in conduit or thru treatment plantMO TOTAL report only all year
D052Solids, total dissolvedMO AVG report only Mar, Sep
D052Mercury, dissolved [as Hg]MO MAX report only May, Sep
D052Mercury, total [as Hg]MO MAX report only May, Sep
D052BOD, carbonaceous [5 day, 20 C]MO AVG <= 25 mg/L all year
D052BOD, carbonaceous [5 day, 20 C]MX WK AV <= 40 mg/L all year
D052BOD, carbonaceous [5 day, 20 C]MO AVG <= 322 kg/d all year
D052BOD, carbonaceous [5 day, 20 C]MX WK AV <= 515 kg/d all year
D052BOD, carb-5 day, 20 deg C, percent removalMO AV MN >= 85 % all year
D052Solids, suspended percent removalMO AV MN >= 85 % all year
S055Precipitation, total defined period/inMO TOTAL report only all year
S055pHMO MIN report only all year
S055pHMO MAX report only all year
S055Solids, total suspendedMO AVG report only all year
S055Solids, total suspendedMO MAX report only all year
S055Nitrogen, total [as N]MO AVG report only all year
S055Nitrogen, Kjeldahl, total [as N]MO AVG report only all year
S055Nitrite + Nitrate total [as N]MO AVG report only all year
S055Phosphorus, total [as P]MO AVG report only all year
S055Flow, in conduit or thru treatment plantMO AVG report only all year
S055Flow, in conduit or thru treatment plantMO MAX report only all year
S055Flow, in conduit or thru treatment plantMO TOTAL report only all year
S055BOD, carbonaceous [5 day, 20 C]MO AVG report only all year
S055BOD, carbonaceous [5 day, 20 C]MO MAX report only 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