Passage Data · Check a report · Use it from your AI

Washington Town of - STP

Sewage treatment plant, Washington, Louisiana. NPDES permit LA0062928, in force until Jan 31, 2031. Last 12 months: over a limit 26 times (last June 2026), 1 required value missing. Source: EPA ECHO, Oct 22, 2026.

Reports due
About 28 days after each period: form A quarterly, form Q quarterly, form Y yearly
Last report on file
June 2026
Oct 2024 – Sep 2025
22 values over a limit, 0 required values missing, 0 of 16 reports late

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

All 26 values over a limit
Period endingParameterReportedLimitOver by
October 2025Oxygen, dissolved [DO], monthly average minimum4.2 mg/L≥ 5 mg/L16%
October 2025Solids, total suspended, monthly average22 mg/L≤ 15 mg/L47%
October 2025Solids, total suspended, weekly average46 mg/L≤ 23 mg/L100%
November 2025Solids, total suspended, monthly average36 mg/L≤ 20 mg/L80%
November 2025Solids, total suspended, weekly average49 mg/L≤ 30 mg/L63%
December 2025pH, instantaneous minimum2.76 SU≥ 6 SU—
January 2026Solids, total suspended, monthly average38 mg/L≤ 20 mg/L90%
January 2026Solids, total suspended, weekly average41 mg/L≤ 30 mg/L37%
February 2026Solids, total suspended, monthly average36.2 lb/d≤ 25 lb/d45%
February 2026Solids, total suspended, monthly average56 mg/L≤ 20 mg/L180%
February 2026Solids, total suspended, weekly average60 mg/L≤ 30 mg/L100%
March 2026Oxygen, dissolved [DO], monthly average minimum4.1 mg/L≥ 5 mg/L18%
March 2026Solids, total suspended, monthly average27.5 lb/d≤ 25 lb/d10%
March 2026Solids, total suspended, monthly average41 mg/L≤ 20 mg/L105%
March 2026Solids, total suspended, weekly average51 mg/L≤ 30 mg/L70%
April 2026Oxygen, dissolved [DO], monthly average minimum4.8 mg/L≥ 5 mg/L4%
April 2026Solids, total suspended, monthly average21 mg/L≤ 15 mg/L40%
April 2026Solids, total suspended, weekly average41 mg/L≤ 23 mg/L78%
May 2026Solids, total suspended, monthly average34.3 lb/d≤ 19 lb/d81%
May 2026Solids, total suspended, monthly average61 mg/L≤ 15 mg/L307%
May 2026Solids, total suspended, weekly average70 mg/L≤ 23 mg/L204%
June 2026BOD, carbonaceous [5 day, 20 C], monthly average11 mg/L≤ 10 mg/L10%
June 2026Oxygen, dissolved [DO], monthly average minimum3 mg/L≥ 5 mg/L40%
June 2026Solids, total suspended, monthly average38.6 lb/d≤ 19 lb/d103%
June 2026Solids, total suspended, monthly average52 mg/L≤ 15 mg/L247%
June 2026Solids, total suspended, weekly average53 mg/L≤ 23 mg/L130%

Limits in force (64)

ParameterStatisticLimitMonths
Oxygen, dissolved [DO]monthly average minimum≥ 5 mg/Lall year
Oxygen, dissolved [DO]monthly average minimum≥ 5 mg/Lall year
pHinstantaneous minimum≥ 6 SUall year
pHinstantaneous minimum≥ 6 SUall year
pHinstantaneous maximum≤ 9 SUall year
pHinstantaneous maximum≤ 9 SUall year
Solids, total suspendedmonthly average≤ 20 mg/LJan, Feb, Mar, Nov, Dec
Solids, total suspendedmonthly average≤ 20 mg/LJan, Feb, Mar, Nov, Dec
Solids, total suspendedmonthly average≤ 15 mg/LApr–Oct
Solids, total suspendedmonthly average≤ 15 mg/LApr–Oct
Solids, total suspendedweekly average≤ 30 mg/LJan, Feb, Mar, Nov, Dec
Solids, total suspendedweekly average≤ 30 mg/LJan, Feb, Mar, Nov, Dec
Solids, total suspendedweekly average≤ 23 mg/LApr–Oct
Solids, total suspendedweekly average≤ 23 mg/LApr–Oct
Solids, total suspendedmonthly average≤ 25 lb/dJan, Feb, Mar, Nov, Dec
Solids, total suspendedmonthly average≤ 25 lb/dJan, Feb, Mar, Nov, Dec
Solids, total suspendedmonthly average≤ 19 lb/dApr–Oct
Solids, total suspendedmonthly average≤ 19 lb/dApr–Oct
Solids, total suspendedmonthly averagereport only (mg/L)all year
Solids, total suspendedweekly averagereport only (mg/L)all year
Nitrogen, total [as N]monthly averagereport only (mg/L)all year
Nitrogen, total [as N]weekly averagereport only (mg/L)all year
Nitrogen, total [as N]monthly averagereport only (lb/d)all year
Nitrogen, ammonia total [as N]monthly average≤ 10 mg/LJan, Feb, Mar, Nov, Dec
Nitrogen, ammonia total [as N]monthly average≤ 10 mg/LJan, Feb, Mar, Nov, Dec
Nitrogen, ammonia total [as N]monthly average≤ 2 mg/LApr–Oct
Nitrogen, ammonia total [as N]monthly average≤ 2 mg/LApr–Oct
Nitrogen, ammonia total [as N]weekly average≤ 20 mg/LJan, Feb, Mar, Nov, Dec
Nitrogen, ammonia total [as N]weekly average≤ 20 mg/LJan, Feb, Mar, Nov, Dec
Nitrogen, ammonia total [as N]weekly average≤ 4 mg/LApr–Oct
Nitrogen, ammonia total [as N]weekly average≤ 4 mg/LApr–Oct
Nitrogen, ammonia total [as N]monthly average≤ 12.5 lb/dJan, Feb, Mar, Nov, Dec
Nitrogen, ammonia total [as N]monthly average≤ 12.5 lb/dJan, Feb, Mar, Nov, Dec
Nitrogen, ammonia total [as N]monthly average≤ 2.5 lb/dApr–Oct
Nitrogen, ammonia total [as N]monthly average≤ 2.5 lb/dApr–Oct
Phosphorus, total [as P]monthly averagereport only (mg/L)all year
Phosphorus, total [as P]weekly averagereport only (mg/L)all year
Phosphorus, total [as P]monthly averagereport only (lb/d)all year
Flow, in conduit or thru treatment plantmonthly averagereport only (MGD)all year
Flow, in conduit or thru treatment plantmonthly averagereport only (MGD)all year
Flow, in conduit or thru treatment plantweekly averagereport only (MGD)all year
Flow, in conduit or thru treatment plantweekly averagereport only (MGD)all year
Chlorine, total residualinstantaneous maximumreport only (mg/L)all year
Chlorine, total residualinstantaneous maximumreport only (mg/L)all year
Coliform, fecal generalmonthly geometric mean≤ 200 #/100mLall year
Coliform, fecal generalmonthly geometric mean≤ 200 #/100mLall year
Coliform, fecal generalweekly geometric mean≤ 400 #/100mLall year
Coliform, fecal generalweekly geometric mean≤ 400 #/100mLall year
BOD, carbonaceous [5 day, 20 C]monthly average≤ 10 mg/LApr–Oct
BOD, carbonaceous [5 day, 20 C]monthly average≤ 10 mg/LApr–Oct
BOD, carbonaceous [5 day, 20 C]monthly average≤ 20 mg/LJan, Feb, Mar, Nov, Dec
BOD, carbonaceous [5 day, 20 C]monthly average≤ 20 mg/LJan, Feb, Mar, Nov, Dec
BOD, carbonaceous [5 day, 20 C]weekly average≤ 15 mg/LApr–Oct
BOD, carbonaceous [5 day, 20 C]weekly average≤ 15 mg/LApr–Oct
BOD, carbonaceous [5 day, 20 C]weekly average≤ 30 mg/LJan, Feb, Mar, Nov, Dec
BOD, carbonaceous [5 day, 20 C]weekly average≤ 30 mg/LJan, Feb, Mar, Nov, Dec
BOD, carbonaceous [5 day, 20 C]monthly average≤ 12.5 lb/dApr–Oct
BOD, carbonaceous [5 day, 20 C]monthly average≤ 12.5 lb/dApr–Oct
BOD, carbonaceous [5 day, 20 C]monthly average≤ 25 lb/dJan, Feb, Mar, Nov, Dec
BOD, carbonaceous [5 day, 20 C]monthly average≤ 25 lb/dJan, Feb, Mar, Nov, Dec
BOD, carbonaceous [5 day, 20 C]monthly averagereport only (mg/L)all year
BOD, carbonaceous [5 day, 20 C]weekly averagereport only (mg/L)all year
BOD, carbonaceous, percent removalminimum≥ 85 %all year
Solids, suspended percent removalminimum≥ 85 %all year

New limits from Feb 1, 2029

ParameterNew limitNew or tighterMedian, last 12 months× new limit
Chlorine, total residual, instantaneous maximum0.033 mg/Lnew1.05 mg/L (4 values)31.8×

How strict are these limits?

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

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

· Save this facility as a site · Superfund sites nearby · Your permits on one board

On EPA ECHO: Facility report · DMR history

Your permit document is the final word. As JSON: /api/v1/permits/LA0062928 · MCP: https://passage-data.com/mcp