Hill City, City of

NPDES permit SD0020885 · Minor POTW · effective, expires 2027-02-28 · 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)
2of 11 forms filed late

Last period with anything received: 2026-07-31. Most often over: Nitrogen, ammonia total [as N] (1).

Reporting

Reports are due about 28 days after each monitoring period ends (read off this permit's own late-day counts in EPA's filings).

Limits in force (26)

OutfallParameterStatisticLimitMonths
002Temperature, water deg. centigrade30DA AVG report only all year
002Temperature, water deg. centigradeDAILY MX report only all year
002Flow rate30DA AVG report only all year
002Flow rateDAILY MX report only all year
002BOD, 5-day, 20 deg. C30DA AVG <= 10 mg/L all year
002BOD, 5-day, 20 deg. CDAILY MX <= 17.5 mg/L all year
002BOD, 5-day, 20 deg. C30DA AVG report only all year
002pHDAILY MN >= 6.6 SU all year
002pHDAILY MX <= 8.6 SU all year
002Solids, total suspended30DA AVG <= 10 mg/L all year
002Solids, total suspendedDAILY MX <= 17.5 mg/L all year
002Solids, total suspended30DA AVG report only all year
002Nitrogen, total [as N]DAILY MX report only all year
002Nitrogen, ammonia total [as N]30DA AVG <= .9 mg/L Sep
002Nitrogen, ammonia total [as N]30DA AVG <= 1 mg/L Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Oct, Nov, Dec
002Nitrogen, ammonia total [as N]DAILY MX <= 1.5 mg/L Sep
002Nitrogen, ammonia total [as N]DAILY MX <= 1.75 mg/L Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Oct, Nov, Dec
002Nitrogen, nitrate total [as N]30DA AVG <= 50 mg/L all year
002Nitrogen, nitrate total [as N]DAILY MX <= 88 mg/L all year
002Phosphorus, total [as P]DAILY MX <= .1 mg/L all year
002Floating solids, waste or visible foam-visualDAILY MX < 0 abst=0;prst=1 all year
002E. coli, colony forming units [CFU]30DA GEO <= 126 #/100mL May, Jun, Jul, Aug, Sep
002E. coli, colony forming units [CFU]DAILY MX <= 235 #/100mL May, Jun, Jul, Aug, Sep
002BOD, 5-day, percent removalMO AV MN >= 85 % all year
002Solids, suspended percent removalMO AV MN >= 85 % all year
002Turbidity, lab, NTUDAILY MX 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