Grantsville, Town of — NPDES permit MD0020761: limits, due date and EPA's record

Grantsville, Town of

Sewage treatment plant, Grantsville, Maryland. NPDES permit MD0020761, in force until Jun 30, 2031. Last 12 months: over a limit 45 times (last August 2026), 4 required values missing, 4 of 15 reports late. Source: EPA ECHO, Oct 22, 2026.

Reports due

About 28 days after each period: outfall 001 form A monthly (19 values), outfall 101 form A monthly (2 values), outfall 001 form Q quarterly

Last report on file

August 2026

Oct 2024 – Sep 2025

60 values over a limit, 0 required values missing, 5 of 16 reports late

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

All 45 values over a limit

Period ending	Parameter	Reported	Limit	Over by
October 2025	E. coli, maximum monthly geometric mean	172.53 MPN/100mL	≤ 126 MPN/100mL	37%
October 2025	Nitrogen, ammonia total [as N], maximum monthly average	23.31 mg/L	≤ 3.9 mg/L	498%
October 2025	Nitrogen, ammonia total [as N], maximum monthly average	56.18 lb/d	≤ 20 lb/d	181%
October 2025	Nitrogen, ammonia total [as N], maximum daily average	28.4 mg/L	≤ 9.4 mg/L	202%
October 2025	Nitrogen, ammonia total [as N], maximum daily average	98.3 lb/d	≤ 47 lb/d	109%
December 2025	E. coli, maximum monthly geometric mean	312.98 MPN/100mL	≤ 126 MPN/100mL	148%
January 2026	E. coli, maximum monthly geometric mean	777.75 MPN/100mL	≤ 126 MPN/100mL	517%
January 2026	Solids, total suspended, maximum monthly average	32.21 mg/L	≤ 30 mg/L	7%
February 2026	E. coli, maximum monthly geometric mean	2419.6 MPN/100mL	≤ 126 MPN/100mL	1820%
March 2026	BOD, 5-day, 20 deg. C, maximum monthly average	179.07 lb/d	≤ 150 lb/d	19%
March 2026	BOD, 5-day, 20 deg. C, maximum monthly average	30.03 mg/L	≤ 30 mg/L	0%
March 2026	E. coli, maximum monthly geometric mean	2419.6 MPN/100mL	≤ 126 MPN/100mL	1820%
April 2026	BOD, 5-day, 20 deg. C, maximum monthly average	263.01 lb/d	≤ 150 lb/d	75%
April 2026	BOD, 5-day, 20 deg. C, maximum monthly average	43.2 mg/L	≤ 30 mg/L	44%
April 2026	BOD, 5-day, 20 deg. C, maximum weekly average	51.5 mg/L	≤ 45 mg/L	14%
April 2026	E. coli, maximum monthly geometric mean	2419.6 MPN/100mL	≤ 126 MPN/100mL	1820%
April 2026	Solids, total suspended, maximum monthly average	209.25 lb/d	≤ 150 lb/d	40%
April 2026	Solids, total suspended, maximum monthly average	34.37 mg/L	≤ 30 mg/L	15%
May 2026	BOD, 5-day, 20 deg. C, maximum monthly average	246.84 lb/d	≤ 150 lb/d	65%
May 2026	BOD, 5-day, 20 deg. C, maximum monthly average	38.14 mg/L	≤ 30 mg/L	27%
May 2026	E. coli, maximum monthly geometric mean	2419.6 MPN/100mL	≤ 126 MPN/100mL	1820%
May 2026	Nitrogen, ammonia total [as N], maximum monthly average	157.98 lb/d	≤ 20 lb/d	690%
May 2026	Nitrogen, ammonia total [as N], maximum monthly average	24.4 mg/L	≤ 3.9 mg/L	526%
May 2026	Nitrogen, ammonia total [as N], maximum daily average	33 mg/L	≤ 9.4 mg/L	251%
May 2026	Nitrogen, ammonia total [as N], maximum daily average	333.57 lb/d	≤ 47 lb/d	610%
May 2026	Solids, total suspended, maximum monthly average	173.12 lb/d	≤ 150 lb/d	15%
June 2026	BOD, 5-day, 20 deg. C, maximum monthly average	30.81 mg/L	≤ 30 mg/L	3%
June 2026	E. coli, maximum monthly geometric mean	2419.6 MPN/100mL	≤ 126 MPN/100mL	1820%
June 2026	Nitrogen, ammonia total [as N], maximum monthly average	21.01 mg/L	≤ 3.9 mg/L	439%
June 2026	Nitrogen, ammonia total [as N], maximum monthly average	84.46 lb/d	≤ 20 lb/d	322%
June 2026	Nitrogen, ammonia total [as N], maximum daily average	134.5 lb/d	≤ 47 lb/d	186%
June 2026	Nitrogen, ammonia total [as N], maximum daily average	25.6 mg/L	≤ 9.4 mg/L	172%
June 2026	pH, minimum	6.47 SU	≥ 6.5 SU	—
July 2026	E. coli, maximum monthly geometric mean	2419.6 MPN/100mL	≤ 126 MPN/100mL	1820%
July 2026	Nitrogen, ammonia total [as N], maximum monthly average	19.07 mg/L	≤ 3.9 mg/L	389%
July 2026	Nitrogen, ammonia total [as N], maximum monthly average	60.6 lb/d	≤ 20 lb/d	203%
July 2026	Nitrogen, ammonia total [as N], maximum daily average	24.4 mg/L	≤ 9.4 mg/L	160%
July 2026	Nitrogen, ammonia total [as N], maximum daily average	96.05 lb/d	≤ 47 lb/d	104%
August 2026	BOD, 5-day, 20 deg. C, maximum monthly average	210.34 lb/d	≤ 150 lb/d	40%
August 2026	E. coli, maximum monthly geometric mean	2419.6 MPN/100mL	≤ 126 MPN/100mL	1820%
August 2026	Nitrogen, ammonia total [as N], maximum monthly average	108.6 lb/d	≤ 20 lb/d	443%
August 2026	Nitrogen, ammonia total [as N], maximum monthly average	14.73 mg/L	≤ 3.9 mg/L	278%
August 2026	Nitrogen, ammonia total [as N], maximum daily average	198.41 lb/d	≤ 47 lb/d	322%
August 2026	Nitrogen, ammonia total [as N], maximum daily average	24.4 mg/L	≤ 9.4 mg/L	160%
August 2026	Solids, total suspended, maximum monthly average	166.47 lb/d	≤ 150 lb/d	11%

Limits in force (32)

Parameter	Statistic	Limit	Months	Outfall
Oxygen, dissolved [DO]	instantaneous minimum	≥ 5 mg/L	all year	001
BOD, 5-day, 20 deg. C	maximum monthly average	≤ 30 mg/L	all year	001
BOD, 5-day, 20 deg. C	maximum weekly average	≤ 45 mg/L	all year	001
BOD, 5-day, 20 deg. C	maximum monthly average	≤ 150 lb/d	all year	001
BOD, 5-day, 20 deg. C	maximum weekly average	≤ 225 lb/d	all year	001
pH	minimum	≥ 6.5 SU	all year	001
pH	maximum	≤ 8.5 SU	all year	001
Solids, total suspended	maximum monthly average	≤ 30 mg/L	all year	001
Solids, total suspended	maximum weekly average	≤ 45 mg/L	all year	001
Solids, total suspended	maximum monthly average	≤ 150 lb/d	all year	001
Solids, total suspended	maximum weekly average	≤ 225 lb/d	all year	001
Nitrogen, total [as N]	quarterly average	report only (mg/L)	all year	001
Nitrogen, organic total [as N]	quarterly average	report only (mg/L)	all year	001
Nitrogen, ammonia total [as N]	maximum monthly average	≤ 3.9 mg/L	May–Oct	001
Nitrogen, ammonia total [as N]	monthly average	report only (mg/L)	Jan, Feb, Mar, Apr, Nov, Dec	001
Nitrogen, ammonia total [as N]	maximum daily average	≤ 9.4 mg/L	May–Oct	001
Nitrogen, ammonia total [as N]	daily maximum	report only (mg/L)	Jan, Feb, Mar, Apr, Nov, Dec	001
Nitrogen, ammonia total [as N]	maximum daily average	≤ 47 lb/d	May–Oct	001
Nitrogen, ammonia total [as N]	daily maximum	report only (lb/d)	Jan, Feb, Mar, Apr, Nov, Dec	001
Nitrogen, ammonia total [as N]	maximum monthly average	≤ 20 lb/d	May–Oct	001
Nitrogen, ammonia total [as N]	monthly average	report only (lb/d)	Jan, Feb, Mar, Apr, Nov, Dec	001
Nitrite + Nitrate total [as N]	quarterly average	report only (mg/L)	all year	001
Phosphorus, total [as P]	quarterly average	report only (mg/L)	all year	001
Phosphate, ortho [as P]	quarterly average	report only (mg/L)	all year	001
Flow, in conduit or thru treatment plant	monthly average	report only (MGD)	all year	001
Flow, in conduit or thru treatment plant	daily maximum	report only (MGD)	all year	001
Chlorine, total residual	maximum	< .027 mg/L	all year	001
E. coli	maximum monthly geometric mean	≤ 126 MPN/100mL	all year	001
BOD, 5-day, percent removal	monthly average minimum	≥ 85 %	all year	001
Solids, suspended percent removal	monthly average minimum	≥ 85 %	all year	001
BOD, 5-day, 20 deg. C	monthly average	report only (mg/L)	all year	101
Solids, total suspended	monthly average	report only (mg/L)	all year	101

New limits from Jan 1, 2028

Parameter	New limit	New or tighter	Median, last 12 months	× new limit
Nitrogen, ammonia total [as N], maximum monthly average	10 lb/d (May–Oct)	tighter	84.46 lb/d (5 values)	8.45×
Nitrogen, ammonia total [as N], maximum monthly average	2 mg/L (May–Oct)	tighter	21.01 mg/L (5 values)	10.5×
Nitrogen, ammonia total [as N], maximum daily average	6.9 mg/L (May–Oct)	tighter	25.6 mg/L (5 values)	3.71×
Nitrogen, ammonia total [as N], maximum daily average	35 lb/d (May–Oct)	tighter	134.5 lb/d (5 values)	3.84×

How strict are these limits?

Chlorine, total residual, maximum .027 mg/L — stricter than 87% of 62 other minor POTWs in Maryland

Nitrogen, ammonia total [as N], maximum daily average 9.4 mg/L — stricter than 30% of 42 other minor POTWs in Maryland

Nitrogen, ammonia total [as N], maximum monthly average 3.9 mg/L — stricter than 20% of 58 other minor POTWs in Maryland

Your permit document is the final word. As JSON: /api/v1/permits/MD0020761 · MCP: https://passage-data.com/mcp