Metro Water Services - Nashville Central STP — NPDES permit TN0020575: limits, due date and EPA's record

NPDES permit TN0020575 · Major POTW · administratively continued, expires 2025-10-31 · EPA's file as of 2026-09-19

This permit expired on 2025-10-31 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: 2026-07-31. Most often over: SSO, Wet Weather (9), SSO, Dry Weather (8), E. coli (3).

Reporting

Reports are due about 15 days after each monitoring period ends (the most common figure among TN permits in EPA's filings — check your permit).

Limits in force (152)

Outfall	Parameter	Statistic	Limit	Months
001	Oxygen, dissolved [DO]	INST MIN	>= 5 mg/L	all year
001	pH	MINIMUM	>= 6 SU	all year
001	pH	MAXIMUM	<= 9 SU	all year
001	Solids, total suspended	MO AVG	<= 30 mg/L	all year
001	Solids, total suspended	WKLY AVG	<= 40 mg/L	all year
001	Solids, total suspended	DAILY MX	<= 45 mg/L	all year
001	Solids, total suspended	MO AVG	<= 25020 lb/d	all year
001	Solids, total suspended	DAILY MX	<= 37530 lb/d	all year
001	Solids, total suspended	WKLY AVG	<= 33360 lb/d	all year
001	Solids, total suspended	MO AVG	report only	all year
001	Solids, total suspended	DAILY MX	report only	all year
001	Solids, total suspended	WKLY AVG	<= 40 mg/L	all year
001	Solids, total suspended	DAILY MX	<= 45 mg/L	all year
001	Solids, total suspended	WKLY AVG	<= 73392 lb/d	all year
001	Solids, total suspended	DAILY MX	<= 82566 lb/d	all year
001	Solids, settleable	DAILY MX	<= 1 mL/L	all year
001	Nitrogen, total [as N]	DAILY MX	report only	all year
001	Nitrogen, ammonia total [as N]	MO AVG	<= 10 mg/L	Jan, Feb, Mar, Apr, Nov, Dec
001	Nitrogen, ammonia total [as N]	MO AVG	<= 5 mg/L	May, Jun, Jul, Aug, Sep, Oct
001	Nitrogen, ammonia total [as N]	WKLY AVG	<= 15 mg/L	Jan, Feb, Mar, Apr, Nov, Dec
001	Nitrogen, ammonia total [as N]	WKLY AVG	<= 7.5 mg/L	May, Jun, Jul, Aug, Sep, Oct
001	Nitrogen, ammonia total [as N]	DAILY MX	<= 20 mg/L	Jan, Feb, Mar, Apr, Nov, Dec
001	Nitrogen, ammonia total [as N]	DAILY MX	<= 10 mg/L	May, Jun, Jul, Aug, Sep, Oct
001	Nitrogen, ammonia total [as N]	MO AVG	<= 8340 lb/d	Jan, Feb, Mar, Apr, Nov, Dec
001	Nitrogen, ammonia total [as N]	MO AVG	<= 4170 lb/d	May, Jun, Jul, Aug, Sep, Oct
001	Nitrogen, ammonia total [as N]	DAILY MX	<= 16680 lb/d	Jan, Feb, Mar, Apr, Nov, Dec
001	Nitrogen, ammonia total [as N]	DAILY MX	<= 8340 lb/d	May, Jun, Jul, Aug, Sep, Oct
001	Nitrogen, ammonia total [as N]	WKLY AVG	<= 6225 lb/d	May, Jun, Jul, Aug, Sep, Oct
001	Nitrogen, ammonia total [as N]	WKLY AVG	<= 12510 lb/d	Jan, Feb, Mar, Apr, Nov, Dec
001	Nitrogen, ammonia total [as N]	WKLY AVG	<= 15 mg/L	all year
001	Nitrogen, ammonia total [as N]	DAILY MX	<= 20 mg/L	all year
001	Nitrogen, ammonia total [as N]	WKLY AVG	<= 27522 lb/d	all year
001	Nitrogen, ammonia total [as N]	DAILY MX	<= 36696 lb/d	all year
001	Phosphorus, total [as P]	DAILY MX	report only	all year
001	Flow, in conduit or thru treatment plant	MO AVG	report only	all year
001	Flow, in conduit or thru treatment plant	DAILY MX	report only	all year
001	Flow, in conduit or thru treatment plant	MO AVG	report only	all year
001	Flow, in conduit or thru treatment plant	DAILY MX	report only	all year
001	Chlorine, total residual	DAILY MX	<= .26 mg/L	all year
001	E. coli	MO GEOMN	<= 126 MPN/100mL	all year
001	E. coli	DAILY MX	<= 487 MPN/100mL	all year
001	SSO, Dry Weather	MO TOTAL	<= 0 occur/mo	all year
001	SSO, Wet Weather	MO TOTAL	<= 0 occur/mo	all year
001	BOD, carbonaceous [5 day, 20 C]	MO AVG	<= 20 mg/L	Jan, Feb, Mar, Apr, Nov, Dec
001	BOD, carbonaceous [5 day, 20 C]	MO AVG	<= 10 mg/L	May, Jun, Jul, Aug, Sep, Oct
001	BOD, carbonaceous [5 day, 20 C]	WKLY AVG	<= 30 mg/L	Jan, Feb, Mar, Apr, Nov, Dec
001	BOD, carbonaceous [5 day, 20 C]	WKLY AVG	<= 15 mg/L	May, Jun, Jul, Aug, Sep, Oct
001	BOD, carbonaceous [5 day, 20 C]	DAILY MX	<= 40 mg/L	Jan, Feb, Mar, Apr, Nov, Dec
001	BOD, carbonaceous [5 day, 20 C]	DAILY MX	<= 25 mg/L	May, Jun, Jul, Aug, Sep, Oct
001	BOD, carbonaceous [5 day, 20 C]	MO AVG	<= 16680 lb/d	Jan, Feb, Mar, Apr, Nov, Dec
001	BOD, carbonaceous [5 day, 20 C]	MO AVG	<= 8340 lb/d	May, Jun, Jul, Aug, Sep, Oct
001	BOD, carbonaceous [5 day, 20 C]	DAILY MX	<= 33360 lb/d	Jan, Feb, Mar, Apr, Nov, Dec
001	BOD, carbonaceous [5 day, 20 C]	DAILY MX	<= 20850 lb/d	May, Jun, Jul, Aug, Sep, Oct
001	BOD, carbonaceous [5 day, 20 C]	WKLY AVG	<= 25020 lb/d	Jan, Feb, Mar, Apr, Nov, Dec
001	BOD, carbonaceous [5 day, 20 C]	WKLY AVG	<= 12510 lb/d	May, Jun, Jul, Aug, Sep, Oct
001	BOD, carbonaceous [5 day, 20 C]	MO AVG	report only	all year
001	BOD, carbonaceous [5 day, 20 C]	DAILY MX	report only	all year
001	BOD, carbonaceous [5 day, 20 C]	WKLY AVG	<= 35 mg/L	all year
001	BOD, carbonaceous [5 day, 20 C]	DAILY MX	<= 40 mg/L	all year
001	BOD, carbonaceous [5 day, 20 C]	WKLY AVG	<= 64218 lb/d	all year
001	BOD, carbonaceous [5 day, 20 C]	DAILY MX	<= 73392 lb/d	all year
001	BOD, carbonaceous, percent removal	MO AV MN	>= 85 %	all year
001	Solids, suspended percent removal	MO AV MN	>= 85 %	all year
001	IC25 Static Renewal 7 Day Chronic Ceriodaphnia dubia	MINIMUM	>= 5.3 %	all year
001	IC25 Static Renewal 7 Day Chronic Chrpimephales	MINIMUM	>= 5.3 %	all year
019	Rainfall duration	MO TOTAL	report only	all year
019	Rainfall	MO TOTAL	report only	all year
019	Flow, in conduit or thru treatment plant	MO AVG	report only	all year
019	Flow, in conduit or thru treatment plant	DAILY MX	report only	all year
019	Rainfall events	MO TOTAL	report only	all year
019	Discharge event observation [Visual Monitoring]	MO TOTAL	report only	all year
01A	Rainfall duration	MO TOTAL	report only	all year
01A	Oxygen, dissolved [DO]	MINIMUM	report only	all year
01A	pH	DAILY MN	>= 6 SU	all year
01A	pH	MAXIMUM	<= 9 SU	all year
01A	Solids, total suspended	MO AVG	report only	all year
01A	Solids, total suspended	WKLY AVG	report only	all year
01A	Solids, total suspended	DAILY MX	report only	all year
01A	Solids, total suspended	MO AVG	report only	all year
01A	Solids, total suspended	DAILY MX	report only	all year
01A	Solids, total suspended	WKLY AVG	report only	all year
01A	Solids, total suspended	DAILY MX	report only	all year
01A	Solids, settleable	DAILY MX	report only	all year
01A	Rainfall	MO TOTAL	report only	all year
01A	Duration	MO TOTAL	report only	all year
01A	Flow, in conduit or thru treatment plant	MO AVG	report only	all year
01A	Flow, in conduit or thru treatment plant	DAILY MX	report only	all year
01A	Chlorine, total residual	DAILY MX	<= 2 mg/L	all year
01A	E. coli	MO GEOMN	<= 126 MPN/100mL	all year
01A	E. coli	DAILY MX	<= 487 MPN/100mL	all year
01A	Rainfall events	MO TOTAL	report only	all year
01A	BOD, carbonaceous [5 day, 20 C]	MO AVG	report only	all year
01A	BOD, carbonaceous [5 day, 20 C]	WKLY AVG	report only	all year
01A	BOD, carbonaceous [5 day, 20 C]	DAILY MX	report only	all year
01A	BOD, carbonaceous [5 day, 20 C]	MO AVG	report only	all year
01A	BOD, carbonaceous [5 day, 20 C]	WKLY AVG	report only	all year
01A	BOD, carbonaceous [5 day, 20 C]	WKLY AVG	report only	all year
01A	BOD, carbonaceous [5 day, 20 C]	DAILY MX	report only	all year
023	Rainfall duration	MO TOTAL	report only	all year
023	Rainfall	MO TOTAL	report only	all year
023	Flow, in conduit or thru treatment plant	MO AVG	report only	all year
023	Flow, in conduit or thru treatment plant	DAILY MX	report only	all year
023	Rainfall events	MO TOTAL	report only	all year
023	Discharge event observation [Visual Monitoring]	MO TOTAL	report only	all year
024	Rainfall duration	MO TOTAL	report only	all year
024	Rainfall	MO TOTAL	report only	all year
024	Flow, in conduit or thru treatment plant	MO AVG	report only	all year
024	Flow, in conduit or thru treatment plant	DAILY MX	report only	all year
024	Rainfall events	MO TOTAL	report only	all year
024	Discharge event observation [Visual Monitoring]	MO TOTAL	report only	all year
033	Rainfall duration	MO TOTAL	report only	all year
033	Rainfall	MO TOTAL	report only	all year
033	Flow, in conduit or thru treatment plant	MO AVG	report only	all year
033	Flow, in conduit or thru treatment plant	DAILY MX	report only	all year
033	Rainfall events	MO TOTAL	report only	all year
033	Discharge event observation [Visual Monitoring]	MO TOTAL	report only	all year
035	Rainfall duration	MO TOTAL	report only	all year
035	Rainfall	MO TOTAL	report only	all year
035	Flow, in conduit or thru treatment plant	MO AVG	report only	all year
035	Flow, in conduit or thru treatment plant	DAILY MX	report only	all year
035	Rainfall events	MO TOTAL	report only	all year
035	Discharge event observation [Visual Monitoring]	MO TOTAL	report only	all year
047	Rainfall duration	MO TOTAL	report only	all year
047	Rainfall	MO TOTAL	report only	all year
047	Flow, in conduit or thru treatment plant	MO AVG	report only	all year
047	Flow, in conduit or thru treatment plant	DAILY MX	report only	all year
047	Rainfall events	MO TOTAL	report only	all year
047	Discharge event observation [Visual Monitoring]	MO TOTAL	report only	all year
IMP1	Temperature, water deg. centigrade	MO AVG	report only	all year
IMP1	Oxygen, dissolved [DO]	MO AVG	report only	all year
IMP1	pH	MO AVG	report only	all year
IMP1	Nitrogen, total [as N]	MO AVG	report only	all year
IMP1	Nitrogen, ammonia total [as N]	MO AVG	report only	all year
IMP1	Phosphorus, total [as P]	MO AVG	report only	all year
IMP1	Chromium, total [as Cr]	MO AVG	report only	all year
IMP1	Copper, total [as Cu]	MO AVG	report only	all year
IMP1	Nickel, total [as Ni]	MO AVG	report only	all year
IMP1	Zinc, total [as Zn]	MO AVG	report only	all year
IMP1	Flow, in conduit or thru treatment plant	MO AVG	report only	all year
IMP1	E. coli	MO AVG	report only	all year
IMP2	Temperature, water deg. centigrade	MO AVG	report only	all year
IMP2	Oxygen, dissolved [DO]	MO AVG	report only	all year
IMP2	pH	MO AVG	report only	all year
IMP2	Nitrogen, total [as N]	MO AVG	report only	all year
IMP2	Nitrogen, ammonia total [as N]	MO AVG	report only	all year
IMP2	Phosphorus, total [as P]	MO AVG	report only	all year
IMP2	Chromium, total [as Cr]	MO AVG	report only	all year
IMP2	Copper, total [as Cu]	MO AVG	report only	all year
IMP2	Nickel, total [as Ni]	MO AVG	report only	all year
IMP2	Zinc, total [as Zn]	MO AVG	report only	all year
IMP2	Flow, in conduit or thru treatment plant	MO AVG	report only	all year
IMP2	E. coli	MO AVG	report only	all year