In Arkansas, for Nitrogen, ammonia total [as N]: 2 plants hold a permit with a new or tighter discharge limit already written into it, taking effect between Jul 1, 2027 and Oct 1, 2029 (10 limits); 1 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
Siloam Springs, City of	AR0020273	AR	Sewage plant, major	5.3 MGD	Nitrogen, ammonia total [as N]	monthly average 0.72 mg/L (May–Oct), tighter	Oct 1, 2029	1.648 mg/L (6 values)	2.29×
Siloam Springs, City of	AR0020273	AR	Sewage plant, major	5.3 MGD	Nitrogen, ammonia total [as N]	7-day average 1.8 mg/L (May–Oct), tighter	Oct 1, 2029	2.46 mg/L (6 values)	1.37×
Marble Falls Water, Sewer, & Solid Waste Suburban Improvement District No 1 WWTP	AR0034088	AR	Sewage plant	.01 MGD	Nitrogen, ammonia total [as N]	monthly average 0.42 lb/d (May–Oct), tighter	Jul 1, 2027	under 3 values	—
Siloam Springs, City of	AR0020273	AR	Sewage plant, major	5.3 MGD	Nitrogen, ammonia total [as N]	monthly average 31.8 lb/d (May–Oct), tighter	Oct 1, 2029	18.54 lb/d (6 values)	0.583×
Siloam Springs, City of	AR0020273	AR	Sewage plant, major	5.3 MGD	Nitrogen, ammonia total [as N]	monthly average 2.1 mg/L (Jan, Feb, Mar, Nov, Dec), tighter	Oct 1, 2029	1.036 mg/L (5 values)	0.493×
Siloam Springs, City of	AR0020273	AR	Sewage plant, major	5.3 MGD	Nitrogen, ammonia total [as N]	7-day average 5.1 mg/L (Jan, Feb, Mar, Nov, Dec), tighter	Oct 1, 2029	2 mg/L (5 values)	0.392×
Siloam Springs, City of	AR0020273	AR	Sewage plant, major	5.3 MGD	Nitrogen, ammonia total [as N]	monthly average 92.8 lb/d (Jan, Feb, Mar, Nov, Dec), tighter	Oct 1, 2029	33.7 lb/d (5 values)	0.363×
Siloam Springs, City of	AR0020273	AR	Sewage plant, major	5.3 MGD	Nitrogen, ammonia total [as N]	7-day average 1.9 mg/L (Apr), tighter	Oct 1, 2029	under 3 values	—
Siloam Springs, City of	AR0020273	AR	Sewage plant, major	5.3 MGD	Nitrogen, ammonia total [as N]	monthly average 0.76 mg/L (Apr), tighter	Oct 1, 2029	under 3 values	—
Siloam Springs, City of	AR0020273	AR	Sewage plant, major	5.3 MGD	Nitrogen, ammonia total [as N]	monthly average 33.6 lb/d (Apr), tighter	Oct 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=AR&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