Arapahoe County Water and Wastewater Authority — NPDES permit CO0047589: limits, due date and EPA's record

Water Supply, major discharger, Arapahoe County, Colorado. NPDES permit CO0047589 expired Aug 31, 2013; its limits still apply. Last 12 months: no values over a limit, 2 of 32 reports late. Source: EPA ECHO, Oct 22, 2026.

Limits in force (149)

Parameter	Statistic	Limit	Months
Oxygen, dissolved [DO]	minimum	≥ 5 mg/L	all year
pH	minimum	≥ 6.5 SU	all year
pH	maximum	≤ 9 SU	all year
Solids, total suspended	30-day average	≤ 30 mg/L	all year
Solids, total suspended	30-day average	≤ 30 mg/L	all year
Solids, total suspended	maximum 7-day average	≤ 45 mg/L	all year
Solids, total suspended	maximum 7-day average	≤ 45 mg/L	all year
Nitrogen, ammonia total [as N]	30-day average	≤ 3.7 mg/L	Jan
Nitrogen, ammonia total [as N]	30-day average	≤ 3.4 mg/L	Feb
Nitrogen, ammonia total [as N]	30-day average	≤ 3.4 mg/L	Mar
Nitrogen, ammonia total [as N]	30-day average	≤ 3.1 mg/L	Apr
Nitrogen, ammonia total [as N]	30-day average	≤ 2.7 mg/L	May
Nitrogen, ammonia total [as N]	30-day average	≤ 2.6 mg/L	Jun
Nitrogen, ammonia total [as N]	30-day average	≤ 2.3 mg/L	Jul
Nitrogen, ammonia total [as N]	30-day average	≤ 2 mg/L	Aug
Nitrogen, ammonia total [as N]	30-day average	≤ 2.2 mg/L	Sep
Nitrogen, ammonia total [as N]	30-day average	≤ 2.3 mg/L	Oct
Nitrogen, ammonia total [as N]	30-day average	≤ 3 mg/L	Nov
Nitrogen, ammonia total [as N]	30-day average	≤ 3.3 mg/L	Dec
Nitrogen, ammonia total [as N]	daily maximum	≤ 14 mg/L	Jan
Nitrogen, ammonia total [as N]	daily maximum	≤ 11 mg/L	Feb
Nitrogen, ammonia total [as N]	daily maximum	≤ 14 mg/L	Mar
Nitrogen, ammonia total [as N]	daily maximum	≤ 14 mg/L	Apr
Nitrogen, ammonia total [as N]	daily maximum	≤ 13 mg/L	May
Nitrogen, ammonia total [as N]	daily maximum	≤ 16 mg/L	Jun
Nitrogen, ammonia total [as N]	daily maximum	≤ 16 mg/L	Jul
Nitrogen, ammonia total [as N]	daily maximum	≤ 13 mg/L	Aug
Nitrogen, ammonia total [as N]	daily maximum	≤ 14 mg/L	Sep
Nitrogen, ammonia total [as N]	daily maximum	≤ 12 mg/L	Oct
Nitrogen, ammonia total [as N]	daily maximum	≤ 14 mg/L	Nov
Nitrogen, ammonia total [as N]	daily maximum	≤ 12 mg/L	Dec
Nitrogen, ammonia total [as N]	rolling average	report only (mg/L)	all year
Nitrogen, nitrite total [as N]	daily maximum	≤ .5 mg/L	all year
Nitrogen, nitrite total [as N]	rolling average	report only (mg/L)	all year
Nitrogen, nitrate total [as N]	daily maximum	≤ 10 mg/L	all year
Nitrogen, nitrate total [as N]	rolling average	report only (mg/L)	all year
Phosphorus, total [as P]	30-day average	≤ .05 mg/L	all year
Phosphorus, total [as P]	30-day average	≤ .2 mg/L	all year
Phosphorus, total [as P]	30-day average	report only (lb/mo)	all year
Phosphorus, total [as P]	annual total	≤ 116 lb/yr	Dec
Cyanide, weak acid, dissociable	30-day average	report only (ug/L)	all year
Cyanide, weak acid, dissociable	daily maximum	≤ 5 ug/L	all year
Cyanide, weak acid, dissociable	rolling average	report only (ug/L)	all year
Sulfide, total [as S]	30-day average	≤ .002 mg/L	all year
Sulfide, total [as S]	rolling average	report only (mg/L)	all year
Chloride [as Cl]	30-day average	≤ 250 mg/L	all year
Chloride [as Cl]	rolling average	report only (mg/L)	all year
Iron, total recoverable	30-day average	≤ 1000 ug/L	all year
Iron, total recoverable	rolling average	report only (ug/L)	all year
Arsenic, total [as As]	30-day average	≤ 100 ug/L	all year
Arsenic, total [as As]	30-day average	≤ 100 ug/L	all year
Arsenic, total [as As]	daily maximum	≤ 50 ug/L	all year
Arsenic, total [as As]	rolling average	report only (mg/L)	all year
Boron, total [as B]	30-day average	≤ .75 mg/L	all year
Boron, total [as B]	rolling average	report only (mg/L)	all year
Cadmium, dissolved [as Cd]	30-day average	≤ 4.5 ug/L	all year
Cadmium, dissolved [as Cd]	30-day average	≤ 6.2 ug/L	all year
Cadmium, dissolved [as Cd]	daily maximum	≤ 12 ug/L	all year
Cadmium, dissolved [as Cd]	daily maximum	≤ 19 ug/L	all year
Cadmium, dissolved [as Cd]	rolling average	report only (ug/L)	all year
Zinc, potentially dissolved	30-day average	≤ 260 ug/L	all year
Zinc, potentially dissolved	30-day average	≤ 382 ug/L	all year
Zinc, potentially dissolved	daily maximum	≤ 260 ug/L	all year
Zinc, potentially dissolved	daily maximum	≤ 379 ug/L	all year
Zinc, potentially dissolved	rolling average	report only (ug/L)	all year
Silver, potentially dissolved	30-day average	≤ 1.6 ug/L	all year
Silver, potentially dissolved	30-day average	≤ 3.5 ug/L	all year
Silver, potentially dissolved	daily maximum	≤ 10 ug/L	all year
Silver, potentially dissolved	daily maximum	≤ 22 ug/L	all year
Silver, potentially dissolved	rolling average	report only (ug/L)	all year
Copper, potentially dissolved	30-day average	≤ 20 ug/L	all year
Copper, potentially dissolved	30-day average	≤ 29 ug/L	all year
Copper, potentially dissolved	daily maximum	≤ 33 ug/L	all year
Copper, potentially dissolved	daily maximum	≤ 50 ug/L	all year
Copper, potentially dissolved	rolling average	report only (ug/L)	all year
Chromium, trivalent, potentially dissolvd	30-day average	≤ 160 ug/L	all year
Chromium, trivalent, potentially dissolvd	30-day average	≤ 231 ug/L	all year
Chromium, trivalent, potentially dissolvd	daily maximum	≤ 1230 ug/L	all year
Chromium, trivalent, potentially dissolvd	daily maximum	≤ 1773 ug/L	all year
Chromium, trivalent, potentially dissolvd	rolling average	report only (ug/L)	all year
Lead, potentially dissolvd	30-day average	≤ 6.9 ug/L	all year
Lead, potentially dissolvd	30-day average	≤ 11 ug/L	all year
Lead, potentially dissolvd	daily maximum	≤ 177 ug/L	all year
Lead, potentially dissolvd	daily maximum	≤ 281 ug/L	all year
Lead, potentially dissolvd	rolling average	report only (ug/L)	all year
Manganese, potentially dissolvd	30-day average	≤ 2256 ug/L	all year
Manganese, potentially dissolvd	30-day average	≤ 2618 ug/L	all year
Manganese, potentially dissolvd	daily maximum	≤ 4083 ug/L	all year
Manganese, potentially dissolvd	daily maximum	≤ 4738 ug/L	all year
Manganese, potentially dissolvd	rolling average	report only (ug/L)	all year
Nickel, potentially dissolvd	30-day average	≤ 115 ug/L	all year
Nickel, potentially dissolvd	30-day average	≤ 168 ug/L	all year
Nickel, potentially dissolvd	daily maximum	≤ 1037 ug/L	all year
Nickel, potentially dissolvd	daily maximum	≤ 1513 ug/L	all year
Nickel, potentially dissolvd	rolling average	report only (ug/L)	all year
Selenium, potentially dissolvd	30-day average	≤ 4.6 ug/L	all year
Selenium, potentially dissolvd	daily maximum	≤ 18.4 ug/L	all year
Selenium, potentially dissolvd	rolling average	report only (ug/L)	all year
Oil and grease	instantaneous maximum	≤ 10 mg/L	all year
Oil and grease	instantaneous maximum	≤ 10 mg/L	all year
E. coli, thermotol, MF, MTEC	30-day geometric mean	≤ 126 #/100mL	all year
E. coli, thermotol, MF, MTEC	maximum 7-day geometric mean	≤ 252 #/100mL	all year
Bromoform	30-day average	≤ 4.3 ug/L	all year
Bromoform	rolling average	report only (ug/L)	all year
Chloroform	30-day average	≤ 3.4 ug/L	all year
Chloroform	daily maximum	≤ 28900 ug/L	all year
Chloroform	rolling average	report only (ug/L)	all year
Toluene	30-day average	≤ 510 ug/L	all year
Toluene	daily maximum	≤ 17500 ug/L	all year
Toluene	rolling average	report only (ug/L)	all year
Chlorodibromomethane	30-day average	≤ 54 ug/L	all year
Chlorodibromomethane	rolling average	report only (ug/L)	all year
Tetrachloroethylene	30-day average	≤ .69 ug/L	all year
Tetrachloroethylene	daily maximum	≤ 5280 ug/L	all year
Tetrachloroethylene	rolling average	report only (ug/L)	all year
Methoxychlor	30-day average	≤ .03 ug/L	all year
Methoxychlor	rolling average	report only (ug/L)	all year
Hexachlorobenzene	30-day average	≤ .00028 ug/L	all year
Hexachlorobenzene	rolling average	report only (ug/L)	all year
Flow, in conduit or thru treatment plant	30-day average	≤ 6.3 MGD	all year
Flow, in conduit or thru treatment plant	30-day average	report only (MGD)	all year
Flow, in conduit or thru treatment plant	daily maximum	report only (MGD)	all year
Flow, in conduit or thru treatment plant	daily maximum	report only (MGD)	all year
Chlorine, total residual	30-day average	≤ .011 mg/L	all year
Chlorine, total residual	daily maximum	≤ .019 mg/L	all year
Toxicity [chronic], Ceriodaphnia dubia	single sample	report only (tox chronic)	all year
Toxicity [chronic], Ceriodaphnia dubia	single sample	report only (tox chronic)	all year
Toxicity [chronic], Ceriodaphnia dubia	single sample	report only (tox chronic)	all year
Toxicity [chronic], Ceriodaphnia dubia	single sample	report only (tox chronic)	all year
Toxicity [chronic], Pimephales promelas [Fathead Minnow]	single sample	report only (tox chronic)	all year
Toxicity [chronic], Pimephales promelas [Fathead Minnow]	single sample	report only (tox chronic)	all year
Toxicity [chronic], Pimephales promelas [Fathead Minnow]	single sample	report only (tox chronic)	all year
Toxicity [chronic], Pimephales promelas [Fathead Minnow]	single sample	report only (tox chronic)	all year
Solids, total dissolved	30-day average	report only (mg/L)	all year
Solids, total dissolved	daily maximum	≤ 3500 mg/L	all year
Mercury, total [as Hg]	30-day average	≤ .01 ug/L	all year
Mercury, total [as Hg]	rolling average	report only (ug/L)	all year
Xylene [mix of m+o+p]	30-day average	≤ 10000 ug/L	all year
Xylene [mix of m+o+p]	rolling average	report only (ug/L)	all year
Oil and grease visual	instantaneous maximum	report only (N=0;Y=1)	all year
Oil and grease visual	instantaneous maximum	report only (N=0;Y=1)	all year
%Effect Static Renewal 7 Day Chronic Ceriodaphnia dubia	single sample	report only (%)	all year
%Effect Static Renewal 7 Day Chronic Ceriodaphnia dubia	single sample	report only (%)	all year
%Effect Static Renewal 7 Day Chronic Ceriodaphnia dubia	minimum value	report only (%)	all year
%Effect Static Renewal 7 Day Chronic Ceriodaphnia dubia	minimum value	≥ 100 %	all year
%Effect Static Renewal 7Day Chronic Pimephales promelas	single sample	report only (%)	all year
%Effect Static Renewal 7Day Chronic Pimephales promelas	single sample	report only (%)	all year
%Effect Static Renewal 7Day Chronic Pimephales promelas	minimum value	report only (%)	all year
%Effect Static Renewal 7Day Chronic Pimephales promelas	minimum value	≥ 100 %	all year

How strict are these limits?

Your permit document is the final word. As JSON: /api/v1/permits/CO0047589 · MCP: https://passage-data.com/mcp