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Mclain Potw

Sewage treatment plant, Mclain, Mississippi. NPDES permit MS0035165, in force until Jan 31, 2030. Last 12 months: over a limit 11 times (last December 2025), 1 of 1 reports late. Source: EPA ECHO, Oct 22, 2026.

Reports due
About 28 days after each period: form Y yearly
Last report on file
December 2025
Oct 2024 – Sep 2025
9 values over a limit, 0 required values missing, 1 of 1 report late

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

Period endingParameterReportedLimitOver by
December 2025BOD, 5-day, 20 deg. C, maximum monthly average30 lb/d≤ 9 lb/d233%
December 2025BOD, 5-day, 20 deg. C, maximum monthly average36 mg/L≤ 30 mg/L20%
December 2025BOD, 5-day, 20 deg. C, maximum weekly average30 lb/d≤ 13.5 lb/d122%
December 2025BOD, 5-day, percent removal, minimum59.5 %≥ 65 %16%
December 2025Chlorine, total residual, maximum monthly average.39 mg/L≤ .011 mg/L3445%
December 2025Chlorine, total residual, maximum weekly average1.55 mg/L≤ .019 mg/L8058%
December 2025Nitrogen, ammonia total [as N], maximum monthly average2.2 lb/d≤ .6 lb/d267%
December 2025Nitrogen, ammonia total [as N], maximum monthly average2.6 mg/L≤ 2 mg/L30%
December 2025Nitrogen, ammonia total [as N], maximum weekly average2.2 lb/d≤ .9 lb/d144%
December 2025Solids, total suspended, maximum monthly average30 lb/d≤ 18 lb/d67%
December 2025Solids, total suspended, maximum weekly average30 lb/d≤ 18 lb/d67%

Limits in force (34)

ParameterStatisticLimitMonths
Oxygen, dissolved [DO]minimum≥ 6 mg/Lall year
BOD, 5-day, 20 deg. Cmaximum monthly average≤ 30 mg/Lall year
BOD, 5-day, 20 deg. Cmaximum weekly average≤ 45 mg/Lall year
BOD, 5-day, 20 deg. Cmaximum monthly average≤ 9 lb/dall year
BOD, 5-day, 20 deg. Cmaximum weekly average≤ 13.5 lb/dall year
BOD, 5-day, 20 deg. Cmaximum monthly averagereport only (mg/L)all year
BOD, 5-day, 20 deg. Cmaximum weekly averagereport only (mg/L)all year
BOD, 5-day, 20 deg. Cmaximum monthly averagereport only (lb/d)all year
BOD, 5-day, 20 deg. Cmaximum weekly averagereport only (lb/d)all year
pHminimum≥ 6 SUall year
pHmaximum≤ 9 SUall year
Solids, total suspendedmaximum monthly average≤ 60 mg/Lall year
Solids, total suspendedmaximum weekly average≤ 60 mg/Lall year
Solids, total suspendedmaximum monthly average≤ 18 lb/dall year
Solids, total suspendedmaximum weekly average≤ 18 lb/dall year
Solids, total suspendedmaximum monthly averagereport only (mg/L)all year
Solids, total suspendedmaximum weekly averagereport only (mg/L)all year
Solids, total suspendedmaximum monthly averagereport only (lb/d)all year
Solids, total suspendedmaximum weekly averagereport only (lb/d)all year
Nitrogen, ammonia total [as N]maximum monthly average≤ 2 mg/Lall year
Nitrogen, ammonia total [as N]maximum weekly average≤ 3 mg/Lall year
Nitrogen, ammonia total [as N]maximum monthly average≤ .6 lb/dall year
Nitrogen, ammonia total [as N]maximum weekly average≤ .9 lb/dall year
Nitrogen, ammonia total [as N]maximum monthly averagereport only (mg/L)all year
Nitrogen, ammonia total [as N]maximum weekly averagereport only (mg/L)all year
Nitrogen, ammonia total [as N]maximum monthly averagereport only (lb/d)all year
Nitrogen, ammonia total [as N]maximum weekly averagereport only (lb/d)all year
Flow, in conduit or thru treatment plantmaximum monthly average≤ .036 MGDall year
Flow, in conduit or thru treatment plantmaximum weekly averagereport only (MGD)all year
Chlorine, total residualmaximum monthly average≤ .011 mg/Lall year
Chlorine, total residualmaximum weekly average≤ .019 mg/Lall year
E. colimaximum monthly average≤ 126 #/100mLall year
E. colimaximum weekly average≤ 410 #/100mLall year
BOD, 5-day, percent removalminimum≥ 65 %all year

New limits from Feb 26, 2028

ParameterNew limitNew or tighterMedian, last 12 months× new limit
Nitrogen, ammonia total [as N], maximum monthly average1.37 mg/Ltighter——
Nitrogen, ammonia total [as N], maximum monthly average0.41 lb/dtighter——
Nitrogen, ammonia total [as N], maximum weekly average0.6 lb/dtighter——
Nitrogen, ammonia total [as N], maximum weekly average2 mg/Ltighter——

How strict are these limits?

Cited limits by parameter: Mississippi'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/MS0035165 · MCP: https://passage-data.com/mcp