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Mill Bottom WWTP

Sewage treatment plant, Frederick, Maryland. NPDES permit MD0065439, in force until Apr 30, 2029. Last 12 months: over a limit 2 times (last January 2026). Source: EPA ECHO, Oct 22, 2026.

Reports due
About 28 days after each period: outfall 001 form A monthly (37 values), outfall 101 form A monthly (2 values)
Last report on file
September 2026
Oct 2024 – Sep 2025
0 values over a limit, 0 required values missing, 0 of 24 reports late

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

Period endingParameterReportedLimitOver by
January 2026Nitrogen, ammonia total [as N], maximum monthly average1.1 mg/L≤ .73 mg/L51%
January 2026Nitrogen, ammonia total [as N], maximum daily average3.2 mg/L≤ 2.4 mg/L33%

Limits in force (47)

ParameterStatisticLimitMonthsOutfall
Oxygen, dissolved [DO]instantaneous minimum≥ 5 mg/Lall year001
BOD, 5-day, 20 deg. Cmaximum monthly average≤ 10 mg/LMay–Oct001
BOD, 5-day, 20 deg. Cmaximum monthly average≤ 30 mg/LJan, Feb, Mar, Apr, Nov, Dec001
BOD, 5-day, 20 deg. Cmaximum weekly average≤ 15 mg/LMay–Oct001
BOD, 5-day, 20 deg. Cmaximum weekly average≤ 45 mg/LJan, Feb, Mar, Apr, Nov, Dec001
BOD, 5-day, 20 deg. Cmaximum monthly average≤ 8.3 lb/dMay–Oct001
BOD, 5-day, 20 deg. Cmaximum monthly average≤ 25 lb/dJan, Feb, Mar, Apr, Nov, Dec001
BOD, 5-day, 20 deg. Cmaximum weekly average≤ 13 lb/dMay–Oct001
BOD, 5-day, 20 deg. Cmaximum weekly average≤ 38 lb/dJan, Feb, Mar, Apr, Nov, Dec001
pHminimum≥ 6.5 SUall year001
pHmaximum≤ 8.5 SUall year001
Solids, total suspendedmaximum monthly average≤ 30 mg/Lall year001
Solids, total suspendedmaximum weekly average≤ 45 mg/Lall year001
Solids, total suspendedmaximum monthly average≤ 25 lb/dall year001
Solids, total suspendedannual maximum≤ 9137 lb/yrall year001
Solids, total suspendedmaximum weekly average≤ 38 lb/dall year001
Solids, total suspendedmonthly totalreport only (lb/mo)all year001
Nitrogen, total [as N]monthly averagereport only (mg/L)all year001
Nitrogen, total [as N]monthly averagereport only (lb/d)all year001
Nitrogen, total [as N]monthly totalreport only (lb/mo)all year001
Nitrogen, total [as N]cumulative totalreport only (lb/yr)all year001
Nitrogen, organic total [as N]monthly averagereport only (mg/L)all year001
Nitrogen, organic total [as N]monthly averagereport only (lb/d)all year001
Nitrogen, ammonia total [as N]maximum monthly average≤ 2.9 mg/LMay–Oct001
Nitrogen, ammonia total [as N]maximum monthly average≤ .73 mg/LJan, Feb, Mar, Apr, Nov, Dec001
Nitrogen, ammonia total [as N]maximum daily average≤ 11 mg/LMay–Oct001
Nitrogen, ammonia total [as N]maximum daily average≤ 2.4 mg/LJan, Feb, Mar, Apr, Nov, Dec001
Nitrogen, ammonia total [as N]maximum monthly average≤ 2.4 lb/dMay–Oct001
Nitrogen, ammonia total [as N]maximum monthly average≤ .61 lb/dJan, Feb, Mar, Apr, Nov, Dec001
Nitrogen, ammonia total [as N]maximum daily average≤ 9.2 lb/dMay–Oct001
Nitrogen, ammonia total [as N]maximum daily average≤ 2 lb/dJan, Feb, Mar, Apr, Nov, Dec001
Nitrite + Nitrate total [as N]monthly averagereport only (mg/L)all year001
Nitrite + Nitrate total [as N]monthly averagereport only (lb/d)all year001
Phosphorus, total [as P]monthly averagereport only (mg/L)all year001
Phosphorus, total [as P]monthly averagereport only (lb/d)all year001
Phosphorus, total [as P]cumulative totalreport only (lb/yr)all year001
Phosphorus, total [as P]monthly totalreport only (lb/mo)all year001
Flow, in conduit or thru treatment plantmonthly averagereport only (MGD)all year001
Flow, in conduit or thru treatment plantdaily maximumreport only (MGD)all year001
Chlorine, total residualmaximum< .1 mg/Lall year001
E. colimaximum monthly geometric mean≤ 126 MPN/100mLall year001
Phosphorous, in total orthophosphatemonthly averagereport only (mg/L)all year001
Phosphorous, in total orthophosphatemonthly averagereport only (lb/d)all year001
BOD, 5-day, percent removalminimum≥ 85 %all year001
Solids, suspended percent removalminimum≥ 85 %all year001
BOD, 5-day, 20 deg. Cmonthly averagereport only (mg/L)all year101
Solids, total suspendedmonthly averagereport only (mg/L)all year101

How strict are these limits?

Cited limits by parameter: Maryland'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/MD0065439 · MCP: https://passage-data.com/mcp