Passage Data · Check a report · Use it from your AI
Sewage treatment plant, Ethan, South Dakota. NPDES permit SD0022934 expired Sep 30, 2024; its limits still apply. Last 12 months: no values over a limit. Source: EPA ECHO, Oct 22, 2026.
| Parameter | Statistic | Limit | Months |
|---|---|---|---|
| Temperature, water deg. centigrade | 30-day average | report only (deg C) | all year |
| Temperature, water deg. centigrade | daily maximum | report only (deg C) | all year |
| Flow rate | 30-day average | report only (MGD) | all year |
| Flow rate | daily maximum | ≤ .45 MGD | all year |
| BOD, 5-day, 20 deg. C | 30-day average | ≤ 30 mg/L | all year |
| BOD, 5-day, 20 deg. C | maximum 7-day average | ≤ 45 mg/L | all year |
| pH | daily minimum | ≥ 6 SU | all year |
| pH | daily maximum | ≤ 9 SU | all year |
| Alkalinity, total [as CaCO3] | 30-day average | ≤ 750 mg/L | all year |
| Alkalinity, total [as CaCO3] | daily maximum | ≤ 1313 mg/L | all year |
| Solids, total suspended | 30-day average | ≤ 30 mg/L | all year |
| Solids, total suspended | maximum 7-day average | ≤ 45 mg/L | all year |
| Nitrogen, total [as N] | daily maximum | report only (mg/L) | all year |
| Nitrogen, ammonia total [as N] | 30-day average | ≤ 3.6 lb/d | May–Oct |
| Nitrogen, ammonia total [as N] | 30-day average | ≤ 11.7 lb/d | Jan, Feb, Mar, Apr, Nov, Dec |
| Nitrogen, ammonia total [as N] | daily maximum | ≤ 17.2 lb/d | May–Oct |
| Nitrogen, ammonia total [as N] | daily maximum | ≤ 25 lb/d | Jan, Feb, Mar, Apr, Nov, Dec |
| Nitrogen, nitrate total [as N] | 30-day average | ≤ 50 mg/L | all year |
| Nitrogen, nitrate total [as N] | daily maximum | ≤ 88 mg/L | all year |
| Phosphorus, total [as P] | daily maximum | report only (mg/L) | all year |
| E. coli, colony forming units [CFU] | 30-day geometric mean | ≤ 630 #/100mL | May–Sep |
| E. coli, colony forming units [CFU] | daily maximum | ≤ 1178 #/100mL | May–Sep |
| Flow, total | monthly total | report only (Mgal) | all year |
| Flowing, Receiving Stream | daily maximum | report only (N=0;Y=1) | all year |
| Duration of discharge | monthly total | report only (d) | all year |
| Duration of discharge | year-to-date total | ≤ 45 d | all year |
Cited limits by parameter: South Dakota's rules and the federal ones.
· Save this facility as a site · Superfund sites nearby · Your permits on one board
On EPA ECHO: Facility report · DMR history
Your permit document is the final word. As JSON: /api/v1/permits/SD0022934 · MCP: https://passage-data.com/mcp