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Clarksdale Potw

Sewage treatment plant, major discharger, Clarksdale, Mississippi. NPDES permit MS0020311, in force until Apr 30, 2028. Last 12 months: over a limit 24 times (last July 2026). Source: EPA ECHO, Oct 22, 2026.

Reports due
About 28 days after each period: form N monthly (55 values)
Renewal application due
Nov 2, 2027 · 180 days before expiry; your permit may set another date
Last report on file
August 2026
Oct 2024 – Sep 2025
39 values over a limit, 0 required values missing, 0 of 12 reports late

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

All 24 values over a limit
Period endingParameterReportedLimitOver by
October 2025Nitrogen, ammonia total [as N], monthly average21 mg/L≤ 5 mg/L320%
October 2025Nitrogen, ammonia total [as N], monthly average248 lb/d≤ 208 lb/d19%
October 2025Nitrogen, ammonia total [as N], maximum weekly average21 mg/L≤ 7.5 mg/L180%
October 2025Solids, suspended percent removal, minimum84 %≥ 85 %7%
November 2025Nitrogen, ammonia total [as N], monthly average22 mg/L≤ 5 mg/L340%
November 2025Nitrogen, ammonia total [as N], monthly average243 lb/d≤ 208 lb/d17%
November 2025Nitrogen, ammonia total [as N], maximum weekly average22 mg/L≤ 7.5 mg/L193%
January 2026Nitrogen, ammonia total [as N], maximum weekly average12 mg/L≤ 7.5 mg/L60%
January 2026Solids, total suspended, maximum weekly average55 mg/L≤ 45 mg/L22%
February 2026BOD, 5-day, 20 deg. C, maximum weekly average64 mg/L≤ 45 mg/L42%
February 2026BOD, 5-day, percent removal, minimum82 %≥ 85 %20%
February 2026Copper, total recoverable, monthly average.1 mg/L≤ .097 mg/L3%
February 2026E. coli, monthly average2900 #/100mL≤ 126 #/100mL2202%
February 2026E. coli, maximum weekly average2335 #/100mL≤ 410 #/100mL470%
February 2026Nitrogen, ammonia total [as N], maximum weekly average12 mg/L≤ 7.5 mg/L60%
February 2026Solids, suspended percent removal, minimum81 %≥ 85 %27%
February 2026Solids, total suspended, maximum weekly average60 mg/L≤ 45 mg/L33%
March 2026E. coli, monthly average290 #/100mL≤ 126 #/100mL130%
March 2026E. coli, maximum weekly average500 #/100mL≤ 410 #/100mL22%
March 2026Solids, suspended percent removal, minimum77 %≥ 85 %53%
March 2026Solids, total suspended, maximum weekly average55 mg/L≤ 45 mg/L22%
April 2026Solids, total suspended, maximum weekly average60 mg/L≤ 45 mg/L33%
July 2026Solids, suspended percent removal, minimum83 %≥ 85 %13%
July 2026Solids, total suspended, maximum weekly average50 mg/L≤ 45 mg/L11%

Limits in force (59)

ParameterStatisticLimitMonths
Oxygen, dissolved [DO]minimum≥ 6 mg/Lall year
Oxygen, dissolved [DO]minimumreport only (mg/L)all year
Oxygen, dissolved [DO]maximumreport only (mg/L)all year
BOD, 5-day, 20 deg. Cmonthly average≤ 25 mg/LMay–Oct
BOD, 5-day, 20 deg. Cmonthly average≤ 30 mg/LJan, Feb, Mar, Apr, Nov, Dec
BOD, 5-day, 20 deg. Cmaximum weekly average≤ 37.5 mg/LMay–Oct
BOD, 5-day, 20 deg. Cmaximum weekly average≤ 45 mg/LJan, Feb, Mar, Apr, Nov, Dec
BOD, 5-day, 20 deg. Cmonthly average≤ 1043 lb/dMay–Oct
BOD, 5-day, 20 deg. Cmonthly average≤ 1248 lb/dJan, Feb, Mar, Apr, Nov, Dec
BOD, 5-day, 20 deg. Cmaximum weekly average≤ 1564 lb/dMay–Oct
BOD, 5-day, 20 deg. Cmaximum weekly average≤ 1877 lb/dJan, Feb, Mar, Apr, Nov, Dec
BOD, 5-day, 20 deg. Cmonthly averagereport only (mg/L)all year
BOD, 5-day, 20 deg. Cmaximum weekly averagereport only (mg/L)all year
BOD, 5-day, 20 deg. Cmonthly 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 suspendedmonthly average≤ 30 mg/Lall year
Solids, total suspendedmaximum weekly average≤ 45 mg/Lall year
Solids, total suspendedmonthly average≤ 1248 lb/dall year
Solids, total suspendedmaximum weekly average≤ 1877 lb/dall year
Solids, total suspendedmonthly averagereport only (mg/L)all year
Solids, total suspendedmaximum weekly averagereport only (mg/L)all year
Solids, total suspendedmonthly averagereport only (lb/d)all year
Solids, total suspendedmaximum weekly averagereport only (lb/d)all year
Nitrogen, total [as N]monthly averagereport only (mg/L)all year
Nitrogen, total [as N]maximum weekly averagereport only (mg/L)all year
Nitrogen, total [as N]maximum monthly average≤ 567.5 lb/dall year
Nitrogen, total [as N]maximum weekly average≤ 851.3 lb/dall year
Nitrogen, total [as N]maximum monthly averagereport only (mg/L)all year
Nitrogen, total [as N]maximum weekly averagereport only (mg/L)all year
Nitrogen, total [as N]monthly averagereport only (lb/d)all year
Nitrogen, total [as N]maximum weekly averagereport only (lb/d)all year
Nitrogen, ammonia total [as N]monthly average≤ 5 mg/Lall year
Nitrogen, ammonia total [as N]maximum weekly average≤ 7.5 mg/Lall year
Nitrogen, ammonia total [as N]monthly average≤ 208 lb/dall year
Nitrogen, ammonia total [as N]maximum weekly average≤ 313 lb/dall year
Nitrogen, ammonia total [as N]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]monthly averagereport only (lb/d)all year
Nitrogen, ammonia total [as N]maximum weekly averagereport only (lb/d)all year
Phosphorus, total [as P]monthly averagereport only (mg/L)all year
Phosphorus, total [as P]maximum weekly averagereport only (mg/L)all year
Phosphorus, total [as P]monthly average≤ 242 lb/dall year
Phosphorus, total [as P]maximum weekly average≤ 363 lb/dall year
Phosphorus, total [as P]maximum monthly averagereport only (mg/L)all year
Phosphorus, total [as P]maximum weekly averagereport only (mg/L)all year
Phosphorus, total [as P]monthly averagereport only (lb/d)all year
Phosphorus, total [as P]maximum weekly averagereport only (lb/d)all year
Copper, total recoverablemonthly average≤ .097 mg/Lall year
Copper, total recoverablemaximum weekly average≤ .17 mg/Lall year
Flow, in conduit or thru treatment plantmonthly average≤ 5 MGDall year
Flow, in conduit or thru treatment plantmaximum weekly averagereport only (MGD)all year
E. colimonthly average≤ 126 #/100mLall year
E. colimaximum weekly average≤ 410 #/100mLall year
BOD, 5-day, percent removalminimum≥ 85 %all year
Solids, suspended percent removalminimum≥ 85 %all year
Sludge settleability 30 minuteminimumreport only (mL/L)all year
Sludge settleability 30 minutemaximumreport only (mL/L)all year

How strict are these limits?

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

Check this month's numbers Email me before each report is due

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On EPA ECHO: Facility report · DMR history

Your permit document is the final word. As JSON: /api/v1/permits/MS0020311 · MCP: https://passage-data.com/mcp