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Dorchester County

Sewage treatment plant, major discharger, North Charleston, South Carolina. NPDES permit SC0038822, in force until Nov 30, 2027. Last 12 months: over a limit once (last April 2026). Source: EPA ECHO, Oct 22, 2026.

Reports due
About 29 days after each period: form 1A monthly (45 values), form 3A quarterly (4 values), form 2A yearly
Renewal application due
Jun 3, 2027 · 180 days before expiry; your permit may set another date
Last report on file
August 2026
Oct 2024 – Sep 2025
0 values over a limit, 0 required values missing, 0 of 16 reports late

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

Period endingParameterReportedLimitOver by
April 2026Enterococci, daily maximum372≤ 104 MPN/100mL258%

Limits in force (63)

ParameterStatisticLimitMonths
Oxygen demand, ultimatemonthly averagereport only (lb/d)Jan, Feb, Nov, Dec
Oxygen demand, ultimatemonthly averagereport only (lb/d)Mar–Oct
Oxygen demand, ultimateweekly averagereport only (lb/d)Jan, Feb, Nov, Dec
Oxygen demand, ultimateweekly averagereport only (lb/d)Mar–Oct
Oxygen demand, ultimatemonthly averagereport only (lb/d)Jan, Feb, Nov, Dec
Oxygen demand, ultimatemonthly averagereport only (lb/d)Mar–Oct
Oxygen demand, ultimateweekly averagereport only (lb/d)Jan, Feb, Nov, Dec
Oxygen demand, ultimateweekly averagereport only (lb/d)Mar–Oct
Oxygen demand, ultimatemonthly average≤ 3550 lb/dJan, Feb, Nov, Dec
Oxygen demand, ultimatemonthly average≤ 2082 lb/dMar–Oct
Oxygen demand, ultimateweekly averagereport only (lb/d)Jan, Feb, Nov, Dec
Oxygen demand, ultimateweekly averagereport only (lb/d)Mar–Oct
Oxygen, dissolved [DO]minimum≥ 5 mg/Lall year
pHminimum≥ 6 SUall year
pHmaximum≤ 8.5 SUall year
Solids, total suspendedmonthly average≤ 30 mg/Lall year
Solids, total suspendedweekly average≤ 45 mg/Lall year
Solids, total suspendedmonthly average≤ 2502 lb/dall year
Solids, total suspendedweekly average≤ 3753 lb/dall 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, total [as N]weekly averagereport only (lb/d)all year
Nitrogen, ammonia total [as N]monthly average≤ 1.92 mg/LMar–Oct
Nitrogen, ammonia total [as N]monthly average≤ 4.65 mg/LJan, Feb, Nov, Dec
Nitrogen, ammonia total [as N]weekly average≤ 2.88 mg/LMar–Oct
Nitrogen, ammonia total [as N]weekly average≤ 6.98 mg/LJan, Feb, Nov, Dec
Nitrogen, ammonia total [as N]monthly average≤ 160 lb/dMar–Oct
Nitrogen, ammonia total [as N]monthly average≤ 388 lb/dJan, Feb, Nov, Dec
Nitrogen, ammonia total [as N]weekly average≤ 240 lb/dMar–Oct
Nitrogen, ammonia total [as N]weekly average≤ 582 lb/dJan, Feb, Nov, Dec
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
Phosphorus, total [as P]weekly averagereport only (lb/d)all year
Copper, total [as Cu]monthly averagereport only (mg/L)all year
Copper, total [as Cu]daily maximumreport only (mg/L)all year
Copper, total [as Cu]monthly averagereport only (lb/d)all year
Copper, total [as Cu]daily maximumreport only (lb/d)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
Chlorine, total residualmonthly average≤ .008 mg/Lall year
Chlorine, total residualdaily maximum≤ .013 mg/Lall year
Chlorine, total residualmonthly average≤ .67 lb/dall year
Chlorine, total residualdaily maximum≤ 1.08 lb/dall year
Enterococci30-day geometric mean≤ 35 MPN/100mLall year
Enterococcidaily maximum≤ 104 MPN/100mLall year
Enterococci30-day geometric mean≤ 35 MPN/100mLall year
Enterococcidaily maximum≤ 800 MPN/100mLall year
Mercury, total [as Hg]monthly averagereport only (mg/L)all year
Mercury, total [as Hg]daily maximumreport only (mg/L)all year
Mercury, total [as Hg]monthly averagereport only (lb/d)all year
Mercury, total [as Hg]daily maximumreport only (lb/d)all year
BOD, carbonaceous [5 day, 20 C]monthly average≤ 9.6 mg/Lall year
BOD, carbonaceous [5 day, 20 C]weekly average≤ 14.4 mg/Lall year
BOD, carbonaceous [5 day, 20 C]monthly average≤ 801 lb/dall year
BOD, carbonaceous [5 day, 20 C]weekly average≤ 1201 lb/dall year
Solids, suspended percent removalmonthly average minimum≥ 85 %all year
Carbonaceous oxygen demand, % removalmonthly average minimum≥ 85 %all year
LC50 Static 48Hr Acute Ceriodaphnia dubiadaily minimumreport only (%)all year
%Effect Static Renewal 7 Day Chronic Ceriodaphnia dubiamonthly average≤ 25 %all year
%Effect Static Renewal 7 Day Chronic Ceriodaphnia dubiadaily maximum≤ 40 %all year
IC25 Static Renewal 7 Day Chronic Ceriodaphnia dubiadaily minimumreport only (%)all year

New limits from Oct 1, 2027

ParameterNew limitNew or tighterMedian, last 12 months× new limit
BOD, carbonaceous [5 day, 20 C], monthly average6.75 mg/Ltighter2 mg/L (11 values)0.296×
BOD, carbonaceous [5 day, 20 C], weekly average10.13 mg/Ltighter2 mg/L (11 values)0.197×

How strict are these limits?

Cited limits by parameter: South Carolina'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/SC0038822 · MCP: https://passage-data.com/mcp