Groton, City of — NPDES permit SD0022187: limits, due date and EPA's record

NPDES permit SD0022187 · Minor POTW · administratively continued, expires 2026-03-31 · EPA's file as of 2026-09-19

This permit expired on 2026-03-31 and is administratively continued: its last limits keep applying until a new permit is issued, and EPA still expects the reports.

EPA's record, 2025-09-01 to 2026-08-31

Last period with anything received: 2026-08-31. Most often over: Nitrogen, ammonia total [as N] (2).

Reporting

Reports are due about 28 days after each monitoring period ends (the most common figure among SD permits in EPA's filings — check your permit).

Limits in force (20)

Outfall	Parameter	Statistic	Limit	Months
001	Temperature, water deg. centigrade	30DA AVG	report only	all year
001	Temperature, water deg. centigrade	DAILY MX	report only	all year
001	Flow rate	30DA AVG	report only	all year
001	Flow rate	DAILY MX	report only	all year
001	BOD, 5-day, 20 deg. C	30DA AVG	<= 30 mg/L	all year
001	BOD, 5-day, 20 deg. C	MX 7D AV	<= 45 mg/L	all year
001	pH	DAILY MN	>= 6 SU	all year
001	pH	DAILY MX	<= 9 SU	all year
001	Solids, total suspended	30DA AVG	<= 90 mg/L	all year
001	Solids, total suspended	MX 7D AV	<= 135 mg/L	all year
001	Nitrogen, total [as N]	DAILY MX	report only	all year
001	Nitrogen, ammonia total [as N]	30DA AVG	<= 3.5 mg/L	Jan, Feb, Mar, Apr, Nov, Dec
001	Nitrogen, ammonia total [as N]	30DA AVG	<= 2.1 mg/L	May, Jun, Jul, Aug, Sep, Oct
001	Nitrogen, ammonia total [as N]	DAILY MX	<= 7.5 mg/L	Jan, Feb, Mar, Apr, Nov, Dec
001	Nitrogen, ammonia total [as N]	DAILY MX	<= 11 mg/L	May, Jun, Jul, Aug, Sep, Oct
001	Phosphorus, total [as P]	DAILY MX	report only	all year
001	E. coli, colony forming units [CFU]	30DA GEO	<= 630 #/100mL	May, Jun, Jul, Aug, Sep
001	E. coli, colony forming units [CFU]	DAILY MX	<= 1178 #/100mL	May, Jun, Jul, Aug, Sep
001	Flow, total	MO TOTAL	report only	all year
001	Duration of discharge	MO TOTAL	report only	all year