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City of Westby

Sewage treatment plant, Westby, Wisconsin. NPDES permit WI0021792 expired Sep 30, 2021; its limits still apply. Last 12 months: over a limit 5 times (last December 2025), 60 required values missing, 19 of 25 reports late. Source: EPA ECHO, Oct 22, 2026.

Reports due
About 15 days after each period: outfall 001 form A monthly (9 values), outfall 001 form Q quarterly (5 values), outfall 701 form A monthly (6 values)
Last report on file
June 2026
Oct 2024 – Sep 2025
0 values over a limit, 0 required values missing, 20 of 28 reports late

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

Period endingParameterReportedLimitOver by
November 2025Solids, total suspended, weekly average40.6667≤ 30 mg/L36%
November 2025Solids, total suspended, weekly average40.6667≤ 30 mg/L36%
December 2025BOD, 5-day, 20 deg. C, weekly average41.6667≤ 30 mg/L39%
December 2025Solids, total suspended, monthly average28.8333≤ 20 mg/L44%
December 2025Solids, total suspended, weekly average92.3333≤ 30 mg/L208%

Limits in force (20)

ParameterStatisticLimitMonthsOutfall
Oxygen, dissolved [DO]daily minimum≥ 4 mg/Lall year001
BOD, 5-day, 20 deg. Cweekly average≤ 30 mg/Lall year001
BOD, 5-day, 20 deg. Cmonthly average≤ 20 mg/Lall year001
pHdaily minimum≥ 6 SUall year001
pHdaily maximum≤ 9 SUall year001
Solids, total suspendedweekly average≤ 30 mg/Lall year001
Solids, total suspendedmonthly average≤ 20 mg/Lall year001
Nitrogen, total [as N]quarterly maximumreport only (mg/L)all year001
Nitrogen, ammonia total [as N]quarterly maximumreport only (mg/L)all year001
Nitrogen, Kjeldahl, total [as N]quarterly maximumreport only (mg/L)all year001
Nitrite + Nitrate total [as N]quarterly maximumreport only (mg/L)all year001
Phosphorus, total [as P]monthly average≤ 6.7 mg/Lall year001
Chloride [as Cl]quarterly maximumreport only (mg/L)all year001
Coliform, fecal generalgeometric mean≤ 400 #/100mLall year001
BOD, 5-day, 20 deg. Cmonthly averagereport only (mg/L)all year701
BOD, 5-day, 20 deg. Cdaily maximumreport only (mg/L)all year701
Solids, total suspendedmonthly averagereport only (mg/L)all year701
Solids, total suspendeddaily maximumreport only (mg/L)all year701
Flow, in conduit or thru treatment plantmonthly averagereport only (MGD)all year701
Flow, in conduit or thru treatment plantdaily maximumreport only (MGD)all year701

How strict are these limits?

Cited limits by parameter: Wisconsin's rules and the federal ones.

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On EPA ECHO: Facility report · DMR history

Your permit document is the final word. As JSON: /api/v1/permits/WI0021792 · MCP: https://passage-data.com/mcp