ROCK HILL CITY OF

NPDES permit SC0020443 · Major POTW · effective, expires 2028-04-30 · EPA's file as of 2026-09-19

Check this month's numbers before you file
Watch this permit — $79 a month. Every Monday, from EPA's newest files: the next report due and when, whether EPA's file holds your last one, any change to this permit's limits or status, and the renewal date.

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

1values over a limit
0required values missing, on 0 form(s)
0of 12 forms filed late

Last period with anything received: 2026-07-31. Most often over: pH (1).

Reporting

Reports are due about 29 days after each monitoring period ends (the most common figure among SC permits in EPA's filings — check your permit).

Limits in force (44)

OutfallParameterStatisticLimitMonths
001Oxygen demand, ultimateMO AVG <= 15471 lb/d all year
001Oxygen demand, ultimateWKLY AVG report only all year
001Oxygen, dissolved [DO]MINIMUM >= 6 mg/L all year
001BOD, 5-day, 20 deg. CMO AVG <= 20.4 mg/L all year
001BOD, 5-day, 20 deg. CWKLY AVG <= 30.6 mg/L all year
001BOD, 5-day, 20 deg. CMO AVG <= 3403 lb/d all year
001BOD, 5-day, 20 deg. CWKLY AVG <= 5105 lb/d all year
001pHMINIMUM >= 6 SU all year
001pHMAXIMUM <= 8.5 SU all year
001Solids, total suspendedMO AVG <= 30 mg/L all year
001Solids, total suspendedWKLY AVG <= 45 mg/L all year
001Solids, total suspendedMO AVG <= 5004 lb/d all year
001Solids, total suspendedWKLY AVG <= 7506 lb/d all year
001Nitrogen, total [as N]MO AVG report only all year
001Nitrogen, total [as N]WKLY AVG report only all year
001Nitrogen, total [as N]MO AVG report only all year
001Nitrogen, total [as N]WKLY AVG report only all year
001Nitrogen, total [as N]1D <= 2000000 lb/yr all year
001Nitrogen, ammonia total [as N]MO AVG report only all year
001Nitrogen, ammonia total [as N]WKLY AVG report only all year
001Nitrogen, ammonia total [as N]MO AVG report only all year
001Nitrogen, ammonia total [as N]WKLY AVG report only all year
001Phosphorus, total [as P]1D <= 45500 lb/yr all year
001Phosphorus, total [as P]MO AVG <= 2 mg/L all year
001Phosphorus, total [as P]WKLY AVG report only all year
001Phosphorus, total [as P]MO AVG report only all year
001Phosphorus, total [as P]WKLY AVG report only all year
001Phosphorus, total [as P]MY <= 5100 lb/mo all year
001Flow, in conduit or thru treatment plantMO AVG report only all year
001Flow, in conduit or thru treatment plantWKLY AVG report only all year
001Chlorine, total residualMO AVG <= .26 mg/L all year
001Chlorine, total residualDAILY MX <= .45 mg/L all year
001Chlorine, total residualMO AVG <= 43.7 lb/d all year
001Chlorine, total residualDAILY MX <= 75.4 lb/d all year
001E. coli30DAVGEO <= 126 MPN/100mL all year
001E. coliDAILY MX <= 349 MPN/100mL all year
001E. coli30DAVGEO <= 126 MPN/100mL all year
001E. coliDAILY MX <= 800 MPN/100mL all year
001BOD, 5-day, percent removalMO AV MN >= 85 % all year
001Solids, suspended percent removalMO AV MN >= 85 % all year
001LC50 Static 48Hr Acute Ceriodaphnia dubiaDAILY MN report only all year
001%Effect Static Renewal 7 Day Chronic Ceriodaphnia dubiaMO AVG report only all year
001%Effect Static Renewal 7 Day Chronic Ceriodaphnia dubiaDAILY MX report only all year
001IC25 Static Renewal 7 Day Chronic Ceriodaphnia dubiaDAILY MN report only all year

Built from EPA's ECHO bulk files. EPA's file, not the permit document, is the source: read your permit. Check a report before you file it · All states