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City of Dayton

Sewage treatment plant, Dayton, Iowa. NPDES permit IA0023558, in force until Apr 30, 2027. Last 12 months: no values over a limit, 1 of 11 reports late. Source: EPA ECHO, Oct 22, 2026.

Reports due: About 15 days after each period: form A monthly (10 values)
Renewal application due: Nov 1, 2026 · 180 days before expiry; your permit may set another date
Last report on file: August 2026
Oct 2024 – Sep 2025: 0 values over a limit, 0 required values missing, 0 of 12 reports late

Limits in force (10)

Parameter	Statistic	Limit	Months
pH	daily minimum	≥ 6.5 SU	all year
pH	daily maximum	≤ 9 SU	all year
Solids, total suspended	30-day average	≤ 80 mg/L	all year
Solids, total suspended	7-day average	≤ 120 mg/L	all year
Chloride [as Cl]	30-day average	≤ 389 mg/L	all year
Chloride [as Cl]	daily maximum	≤ 629 mg/L	all year
Chloride [as Cl]	30-day average	≤ 6029 lb/d	all year
Chloride [as Cl]	daily maximum	≤ 9755 lb/d	all year
BOD, carbonaceous [5 day, 20 C]	30-day average	≤ 25 mg/L	all year
BOD, carbonaceous [5 day, 20 C]	7-day average	≤ 40 mg/L	all year

New limits from Apr 1, 2027

Parameter	New limit	New or tighter	Median, last 12 months	× new limit
E. coli, geometric mean	149 #/100mL (Mar–Nov)	new	—	—

How strict are these limits?

Chloride [as Cl], 30-day average 389 mg/L — stricter than 56% of 69 other minor POTWs in Iowa; 43% have the same limit
pH, daily minimum at least 6.5 SU — stricter than 56% of 699 other minor POTWs in Iowa; 44% have the same limit
Chloride [as Cl], daily maximum 629 mg/L — stricter than 47% of 69 other minor POTWs in Iowa; 52% have the same limit

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

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On EPA ECHO: Facility report · DMR history

Your permit document is the final word. As JSON: /api/v1/permits/IA0023558 · MCP: https://passage-data.com/mcp