Rocky Ford City of — NPDES permit CO0023850: limits, due date and EPA's record

Sewage treatment plant, major discharger, Rocky Ford, Colorado. NPDES permit CO0023850 expired Jul 31, 2020; its limits still apply. Last 12 months: over a limit 13 times (last August 2026). Source: EPA ECHO, Oct 22, 2026.

Last 12 months (Oct 1, 2025 – Sep 30, 2026)

Limits in force (63)

Period ending	Parameter	Reported	Limit	Over by
December 2025	Chlorine, total residual, instantaneous maximum	.08 mg/L	≤ .076 mg/L	5%
February 2026	Selenium, potentially dissolvd, 30-day average	6 ug/L	≤ 4.6 ug/L	30%
March 2026	BOD, carb-5 day, 20 deg C, percent removal, monthly average minimum	84 %	≥ 85 %	7%
March 2026	Selenium, potentially dissolvd, 30-day average	8.3 ug/L	≤ 4.6 ug/L	80%
April 2026	Selenium, potentially dissolvd, 30-day average	8.6 ug/L	≤ 4.6 ug/L	87%
May 2026	BOD, carb-5 day, 20 deg C, percent removal, monthly average minimum	84.44 %	≥ 85 %	4%
May 2026	Flow, in conduit or thru treatment plant, 30-day average	.51 MGD	≤ .5 MGD	2%
May 2026	Selenium, potentially dissolvd, 30-day average	8.5 ug/L	≤ 4.6 ug/L	85%
June 2026	BOD, carb-5 day, 20 deg C, percent removal, monthly average minimum	83.33 %	≥ 85 %	11%
July 2026	Solids, total suspended, 30-day average	82 mg/L	≤ 75 mg/L	9%
July 2026	Sulfide-hydrogen sulfide [undissociated], 30-day average	5.1 mg/L	≤ .051 mg/L	9900%
August 2026	Chlorine, total residual, instantaneous maximum	.09 mg/L	≤ .076 mg/L	18%
August 2026	Sulfide-hydrogen sulfide [undissociated], 30-day average	3.6 mg/L	≤ .051 mg/L	6959%

Parameter	Statistic	Limit	Months	Outfall
Temperature, water deg. centigrade	maximum weekly average	report only (deg C)	all year	001
Temperature, water deg. centigrade	daily maximum	report only (deg C)	all year	001
pH	minimum	≥ 6.5 SU	all year	001
pH	maximum	≤ 9 SU	all year	001
Solids, total suspended	30-day average	≤ 75 mg/L	all year	001
Solids, total suspended	maximum 7-day average	≤ 110 mg/L	all year	001
Nitrogen, ammonia total [as N]	30-day average	≤ 60 mg/L	Apr	001
Nitrogen, ammonia total [as N]	30-day average	≤ 37 mg/L	Feb	001
Nitrogen, ammonia total [as N]	30-day average	≤ 38 mg/L	Jan	001
Nitrogen, ammonia total [as N]	30-day average	≤ 49 mg/L	Jun	001
Nitrogen, ammonia total [as N]	30-day average	≤ 59 mg/L	Aug	001
Nitrogen, ammonia total [as N]	30-day average	≤ 52 mg/L	Jul	001
Nitrogen, ammonia total [as N]	30-day average	≤ 82 mg/L	May	001
Nitrogen, ammonia total [as N]	30-day average	≤ 40 mg/L	Dec	001
Nitrogen, ammonia total [as N]	30-day average	≤ 35 mg/L	Mar	001
Nitrogen, ammonia total [as N]	30-day average	≤ 45 mg/L	Oct	001
Nitrogen, ammonia total [as N]	30-day average	≤ 47 mg/L	Nov	001
Nitrogen, ammonia total [as N]	30-day average	≤ 54 mg/L	Sep	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 134 mg/L	Apr	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 36 mg/L	Feb	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 43 mg/L	Jan	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 142 mg/L	Jun	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 76 mg/L	Aug	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 128 mg/L	Jul	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 213 mg/L	May	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 40 mg/L	Dec	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 61 mg/L	Mar	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 67 mg/L	Oct	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 67 mg/L	Nov	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 56 mg/L	Sep	001
Nitrogen, inorganic total	daily maximum	≤ 66 mg/L	all year	001
Cyanide, weak acid, dissociable	daily maximum	report only (ug/L)	all year	001
Arsenic, total recoverable	30-day average	report only (ug/L)	all year	001
Copper, potentially dissolved	30-day average	≤ 199 ug/L	all year	001
Copper, potentially dissolved	daily maximum	≤ 199 ug/L	all year	001
Selenium, potentially dissolvd	30-day average	≤ 4.6 ug/L	all year	001
Selenium, potentially dissolvd	daily maximum	≤ 29 ug/L	all year	001
Oil and grease	instantaneous maximum	≤ 10 mg/L	all year	001
Flow, in conduit or thru treatment plant	30-day average	≤ .5 MGD	all year	001
Flow, in conduit or thru treatment plant	daily maximum	report only (MGD)	all year	001
Chlorine, total residual	30-day average	≤ .076 mg/L	all year	001
Chlorine, total residual	instantaneous maximum	≤ .076 mg/L	all year	001
E. coli	30-day geometric mean	≤ 126 #/100mL	all year	001
E. coli	maximum 7-day geometric mean	≤ 252 #/100mL	all year	001
Sulfide-hydrogen sulfide [undissociated]	30-day average	≤ .051 mg/L	all year	001
BOD, carbonaceous [5 day, 20 C]	30-day average	≤ 25 mg/L	all year	001
BOD, carbonaceous [5 day, 20 C]	maximum 7-day average	≤ 40 mg/L	all year	001
BOD, carb-5 day, 20 deg C, percent removal	monthly average minimum	≥ 85 %	all year	001
Oil and grease visual	instantaneous maximum	report only (abst=0;prst=1)	all year	001
Plant capacity fact. percent of capacity	30-day average	report only (%)	all year	300
Plant capacity fact. percent of capacity	30-day average	report only (%)	all year	300
BOD, 5-day, 20 deg. C	30-day average	report only (mg/L)	all year	300
BOD, 5-day, 20 deg. C	maximum 7-day average	report only (mg/L)	all year	300
BOD, 5-day, 20 deg. C	30-day average	report only (lb/d)	all year	300
BOD, 5-day, 20 deg. C	maximum 7-day average	report only (lb/d)	all year	300
Solids, total suspended	30-day average	report only (mg/L)	all year	300
Solids, total suspended	maximum 7-day average	report only (mg/L)	all year	300
Flow, in conduit or thru treatment plant	30-day average	report only (MGD)	all year	300
Flow, in conduit or thru treatment plant	daily maximum	report only (MGD)	all year	300
BOD, carbonaceous [5 day, 20 C]	30-day average	report only (mg/L)	all year	300
BOD, carbonaceous [5 day, 20 C]	maximum 7-day average	report only (mg/L)	all year	300
Temperature, water deg. centigrade	maximum weekly average	report only (deg C)	all year	UST1
Temperature, water deg. centigrade	daily maximum	report only (deg C)	all year	UST1

How strict are these limits?

Your permit document is the final word. As JSON: /api/v1/permits/CO0023850 · MCP: https://passage-data.com/mcp