Passage Data · Check a report · Use it from your AI

Keystone, Town of

Sewage treatment plant, Keystone, South Dakota. NPDES permit SD0024007 expired Jun 30, 2025; its limits still apply. Last 12 months: no values over a limit, 1 of 12 reports late. Source: EPA ECHO, Oct 22, 2026.

Reports due
About 28 days after each period: form A monthly (23 values)
Last report on file
September 2026
Oct 2024 – Sep 2025
19 values over a limit, 0 required values missing, 0 of 12 reports late

Limits in force (29)

ParameterStatisticLimitMonths
Temperature, water deg. centigrade30-day averagereport only (deg C)all year
Temperature, water deg. centigradedaily maximumreport only (deg C)all year
Flow rate30-day averagereport only (MGD)all year
Flow ratedaily maximumreport only (MGD)all year
BOD, 5-day, 20 deg. C30-day average≤ 10 mg/Lall year
BOD, 5-day, 20 deg. Cdaily maximum≤ 17.5 mg/Lall year
BOD, 5-day, 20 deg. C30-day averagereport only (mg/L)all year
pHdaily minimum≥ 6.6 SUall year
pHdaily maximum≤ 8.6 SUall year
Solids, total suspended30-day average≤ 10 mg/Lall year
Solids, total suspendeddaily maximum≤ 17.5 mg/Lall year
Solids, total suspended30-day averagereport only (mg/L)all year
Nitrogen, total [as N]daily maximumreport only (mg/L)all year
Nitrogen, ammonia total [as N]30-day averagereport only (mg/L)all year
Nitrogen, ammonia total [as N]daily maximumreport only (mg/L)all year
Nitrogen, ammonia total [as N]30-day average≤ 1.9 lb/dJan–Mar
Nitrogen, ammonia total [as N]30-day average≤ 5.3 lb/dApr–Jun
Nitrogen, ammonia total [as N]30-day average≤ 1.3 lb/dJul–Sep
Nitrogen, ammonia total [as N]30-day average≤ 2.3 lb/dOct–Dec
Nitrogen, ammonia total [as N]daily maximum≤ 3.9 lb/dJan–Mar
Nitrogen, ammonia total [as N]daily maximum≤ 12.6 lb/dApr–Jun
Nitrogen, ammonia total [as N]daily maximum≤ 4.2 lb/dJul–Sep
Nitrogen, ammonia total [as N]daily maximum≤ 4.4 lb/dOct–Dec
Phosphorus, total [as P]daily maximumreport only (mg/L)all year
E. coli, colony forming units [CFU]30-day geometric mean≤ 630 CFU/100mLMay–Sep
E. coli, colony forming units [CFU]daily maximum≤ 1178 CFU/100mLMay–Sep
Flow, totalmonthly totalreport only (Mgal)all year
BOD, 5-day, percent removalmonthly average minimum≥ 85 %all year
Solids, suspended percent removalmonthly average minimum≥ 85 %all year

How strict are these limits?

Cited limits by parameter: South Dakota's rules and the federal ones.

Check this month's numbers Email me before each report is due

· 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/SD0024007 · MCP: https://passage-data.com/mcp