In South Dakota, for Nitrogen, ammonia total [as N]: 4 plants hold a permit with a new or tighter discharge limit already written into it, taking effect between Sep 1, 2027 and Jan 1, 2029 (53 limits); 0 of them reported a median above that limit between Oct 1, 2025 and Sep 30, 2026. EPA's file of Oct 16, 2026.

By state: all · IA 90 · LA 80 · MS 63 · MD 45 · PA 45 · OH 40 · MI 33 · VA 33 · GA 22 · SC 8 · NE 7 · NY 7 · TX 7 · IN 6 · KS 6 · MO 5 · UT 5 · OR 4 · SD 4 · TN 4 · IL 3 · AR 2 · MN 2 · NJ 2 · NM 2 · CO 1

Plant	Permit	State	Type	Design flow	Parameter	New limit	Effective	Today's median	× limit
Colman, City of	SD0022551	SD	Sewage plant	.065 MGD	Nitrogen, ammonia total [as N]	30-day average 2.9 mg/L (Dec), tighter	Sep 1, 2027	under 3 values	—
Colman, City of	SD0022551	SD	Sewage plant	.065 MGD	Nitrogen, ammonia total [as N]	30-day average 1.6 mg/L (Apr), tighter	Sep 1, 2027	under 3 values	—
Colman, City of	SD0022551	SD	Sewage plant	.065 MGD	Nitrogen, ammonia total [as N]	30-day average 1.4 mg/L (May), tighter	Sep 1, 2027	under 3 values	—
Colman, City of	SD0022551	SD	Sewage plant	.065 MGD	Nitrogen, ammonia total [as N]	30-day average 1 mg/L (Aug), tighter	Sep 1, 2027	under 3 values	—
Colman, City of	SD0022551	SD	Sewage plant	.065 MGD	Nitrogen, ammonia total [as N]	30-day average 3.4 mg/L (Feb), tighter	Sep 1, 2027	under 3 values	—
Colman, City of	SD0022551	SD	Sewage plant	.065 MGD	Nitrogen, ammonia total [as N]	30-day average 1.2 mg/L (Sep), tighter	Sep 1, 2027	under 3 values	—
Colman, City of	SD0022551	SD	Sewage plant	.065 MGD	Nitrogen, ammonia total [as N]	30-day average 4 mg/L (Jan), tighter	Sep 1, 2027	under 3 values	—
Colman, City of	SD0022551	SD	Sewage plant	.065 MGD	Nitrogen, ammonia total [as N]	30-day average 2.3 mg/L (Nov), tighter	Sep 1, 2027	under 3 values	—
Colman, City of	SD0022551	SD	Sewage plant	.065 MGD	Nitrogen, ammonia total [as N]	30-day average 1 mg/L (Jun), tighter	Sep 1, 2027	under 3 values	—
Colman, City of	SD0022551	SD	Sewage plant	.065 MGD	Nitrogen, ammonia total [as N]	30-day average 1.7 mg/L (Oct), tighter	Sep 1, 2027	under 3 values	—
Colman, City of	SD0022551	SD	Sewage plant	.065 MGD	Nitrogen, ammonia total [as N]	30-day average 3.5 mg/L (Mar), tighter	Sep 1, 2027	under 3 values	—
Colman, City of	SD0022551	SD	Sewage plant	.065 MGD	Nitrogen, ammonia total [as N]	30-day average 1 mg/L (Jul), tighter	Sep 1, 2027	under 3 values	—
Colman, City of	SD0022551	SD	Sewage plant	.065 MGD	Nitrogen, ammonia total [as N]	daily maximum 4.5 mg/L (Aug), tighter	Sep 1, 2027	under 3 values	—
Colman, City of	SD0022551	SD	Sewage plant	.065 MGD	Nitrogen, ammonia total [as N]	daily maximum 3.3 mg/L (Jun), tighter	Sep 1, 2027	under 3 values	—
Colman, City of	SD0022551	SD	Sewage plant	.065 MGD	Nitrogen, ammonia total [as N]	daily maximum 5.1 mg/L (Jul), tighter	Sep 1, 2027	under 3 values	—
Platte, City of	SD0020354	SD	Sewage plant	.16 MGD	Nitrogen, ammonia total [as N]	30-day average 4.2 mg/L (Feb), tighter	Dec 1, 2028	under 3 values	—
Platte, City of	SD0020354	SD	Sewage plant	.16 MGD	Nitrogen, ammonia total [as N]	daily maximum 8.1 mg/L (Jan), tighter	Dec 1, 2028	under 3 values	—
Viborg, City of	SD0020541	SD	Sewage plant	.13 MGD	Nitrogen, ammonia total [as N]	30-day average 1.5 mg/L (Oct), tighter	Dec 1, 2028	under 3 values	—
Viborg, City of	SD0020541	SD	Sewage plant	.13 MGD	Nitrogen, ammonia total [as N]	30-day average 3.1 mg/L (Feb), tighter	Dec 1, 2028	under 3 values	—
Viborg, City of	SD0020541	SD	Sewage plant	.13 MGD	Nitrogen, ammonia total [as N]	30-day average 2.1 mg/L (Nov), tighter	Dec 1, 2028	under 3 values	—
Viborg, City of	SD0020541	SD	Sewage plant	.13 MGD	Nitrogen, ammonia total [as N]	30-day average 3.3 mg/L (Jan), tighter	Dec 1, 2028	under 3 values	—
Viborg, City of	SD0020541	SD	Sewage plant	.13 MGD	Nitrogen, ammonia total [as N]	30-day average 1 mg/L (Jun), tighter	Dec 1, 2028	under 3 values	—
Viborg, City of	SD0020541	SD	Sewage plant	.13 MGD	Nitrogen, ammonia total [as N]	30-day average 1.6 mg/L (Apr), tighter	Dec 1, 2028	under 3 values	—
Viborg, City of	SD0020541	SD	Sewage plant	.13 MGD	Nitrogen, ammonia total [as N]	30-day average 1 mg/L (May), tighter	Dec 1, 2028	under 3 values	—
Viborg, City of	SD0020541	SD	Sewage plant	.13 MGD	Nitrogen, ammonia total [as N]	30-day average 1 mg/L (Jul), tighter	Dec 1, 2028	under 3 values	—
Viborg, City of	SD0020541	SD	Sewage plant	.13 MGD	Nitrogen, ammonia total [as N]	30-day average 2.5 mg/L (Dec), tighter	Dec 1, 2028	under 3 values	—
Viborg, City of	SD0020541	SD	Sewage plant	.13 MGD	Nitrogen, ammonia total [as N]	30-day average 1 mg/L (Sep), tighter	Dec 1, 2028	under 3 values	—
Viborg, City of	SD0020541	SD	Sewage plant	.13 MGD	Nitrogen, ammonia total [as N]	30-day average 2.4 mg/L (Mar), tighter	Dec 1, 2028	under 3 values	—
Viborg, City of	SD0020541	SD	Sewage plant	.13 MGD	Nitrogen, ammonia total [as N]	30-day average 1 mg/L (Aug), tighter	Dec 1, 2028	under 3 values	—
Viborg, City of	SD0020541	SD	Sewage plant	.13 MGD	Nitrogen, ammonia total [as N]	daily maximum 2.6 mg/L (Jul), tighter	Dec 1, 2028	under 3 values	—
Viborg, City of	SD0020541	SD	Sewage plant	.13 MGD	Nitrogen, ammonia total [as N]	daily maximum 5 mg/L (Sep), tighter	Dec 1, 2028	under 3 values	—
Mitchell, City of	SD0023361	SD	Sewage plant, major	2 MGD	Nitrogen, ammonia total [as N]	30-day average 165 lb/d (Jan), tighter	Jan 1, 2029	under 3 values	—
Mitchell, City of	SD0023361	SD	Sewage plant, major	2 MGD	Nitrogen, ammonia total [as N]	30-day average 279 lb/d (Jan, Feb), tighter	Jan 1, 2029	under 3 values	—
Mitchell, City of	SD0023361	SD	Sewage plant, major	2 MGD	Nitrogen, ammonia total [as N]	30-day average 712 lb/d (Jan, Feb), tighter	Jan 1, 2029	under 3 values	—
Mitchell, City of	SD0023361	SD	Sewage plant, major	2 MGD	Nitrogen, ammonia total [as N]	30-day average 92 lb/d (Apr), tighter	Jan 1, 2029	under 3 values	—
Mitchell, City of	SD0023361	SD	Sewage plant, major	2 MGD	Nitrogen, ammonia total [as N]	30-day average 92 lb/d (Apr), tighter	Jan 1, 2029	under 3 values	—
Mitchell, City of	SD0023361	SD	Sewage plant, major	2 MGD	Nitrogen, ammonia total [as N]	30-day average 90 lb/d (May), tighter	Jan 1, 2029	under 3 values	—
Mitchell, City of	SD0023361	SD	Sewage plant, major	2 MGD	Nitrogen, ammonia total [as N]	30-day average 80 lb/d (May), tighter	Jan 1, 2029	under 3 values	—
Mitchell, City of	SD0023361	SD	Sewage plant, major	2 MGD	Nitrogen, ammonia total [as N]	30-day average 122 lb/d (Jul–Sep), tighter	Jan 1, 2029	under 3 values	—
Mitchell, City of	SD0023361	SD	Sewage plant, major	2 MGD	Nitrogen, ammonia total [as N]	30-day average 294 lb/d (Oct, Nov), tighter	Jan 1, 2029	under 3 values	—
Mitchell, City of	SD0023361	SD	Sewage plant, major	2 MGD	Nitrogen, ammonia total [as N]	30-day average 159 lb/d (May, Jun), tighter	Jan 1, 2029	under 3 values	—
Mitchell, City of	SD0023361	SD	Sewage plant, major	2 MGD	Nitrogen, ammonia total [as N]	30-day average 50 lb/d (Jul–Sep), tighter	Jan 1, 2029	under 3 values	—
Mitchell, City of	SD0023361	SD	Sewage plant, major	2 MGD	Nitrogen, ammonia total [as N]	30-day average 279 lb/d (Mar), tighter	Jan 1, 2029	under 3 values	—
Mitchell, City of	SD0023361	SD	Sewage plant, major	2 MGD	Nitrogen, ammonia total [as N]	30-day average 82 lb/d (Jun), tighter	Jan 1, 2029	under 3 values	—
Mitchell, City of	SD0023361	SD	Sewage plant, major	2 MGD	Nitrogen, ammonia total [as N]	30-day average 196 lb/d (Apr), tighter	Jan 1, 2029	under 3 values	—
Mitchell, City of	SD0023361	SD	Sewage plant, major	2 MGD	Nitrogen, ammonia total [as N]	daily maximum 744 lb/d (Jan), tighter	Jan 1, 2029	under 3 values	—
Mitchell, City of	SD0023361	SD	Sewage plant, major	2 MGD	Nitrogen, ammonia total [as N]	daily maximum 1295 lb/d (Jan, Feb), tighter	Jan 1, 2029	under 3 values	—
Mitchell, City of	SD0023361	SD	Sewage plant, major	2 MGD	Nitrogen, ammonia total [as N]	daily maximum 448 lb/d (Apr), tighter	Jan 1, 2029	under 3 values	—
Mitchell, City of	SD0023361	SD	Sewage plant, major	2 MGD	Nitrogen, ammonia total [as N]	daily maximum 141 lb/d (May), tighter	Jan 1, 2029	under 3 values	—
Mitchell, City of	SD0023361	SD	Sewage plant, major	2 MGD	Nitrogen, ammonia total [as N]	daily maximum 537 lb/d (Jul–Sep), tighter	Jan 1, 2029	under 3 values	—
Mitchell, City of	SD0023361	SD	Sewage plant, major	2 MGD	Nitrogen, ammonia total [as N]	daily maximum 207 lb/d (Jul–Sep), tighter	Jan 1, 2029	under 3 values	—
Mitchell, City of	SD0023361	SD	Sewage plant, major	2 MGD	Nitrogen, ammonia total [as N]	daily maximum 354 lb/d (Jun), tighter	Jan 1, 2029	under 3 values	—
Mitchell, City of	SD0023361	SD	Sewage plant, major	2 MGD	Nitrogen, ammonia total [as N]	daily maximum 986 lb/d (Apr), tighter	Jan 1, 2029	under 3 values	—

Each limit is one EPA's ICIS-NPDES file holds on the permit's current version with a begin date after today, enforceable and numeric, either on a parameter the outfall was never limited on (new) or lower than the limit in force (tighter). Today's median is the plant's own reported values for the same outfall, statistic and unit between Oct 1, 2025 and Sep 30, 2026, with how many; none is shown where most were below a detection limit. Read the permit before relying on a value.

Sell to these plants? The list for your states every week, with every plant over a limit on your pollutant, as a spreadsheet, by API and by email when a new one appears: ask for the plant list, or write to info@passage-data.com. What a seller gets.

For programs and AI agents: a state's permits with these limits as JSON at /api/v1/permits?state=SD&upcoming=true, narrowed with &facility_type=potw or &min_flow_mgd=1; the whole list at /dmr/data/upcoming.json; or add https://passage-data.com/mcp as a remote MCP server (tool list_permits). Free, no key. llms.txt

From EPA's ECHO data, not the permit document itself: your permit is the final word. All states

Plants facing new discharge limits — by state and pollutant