Durango La Plata County Airport — NPDES permit CO0047457: limits, due date and EPA's record

Sewerage Systems, La Plata County, Colorado. NPDES permit CO0047457 expired Oct 31, 2023; its limits still apply. Last 12 months: no values over a limit. Source: EPA ECHO, Oct 22, 2026.

Limits in force (200)

Parameter	Statistic	Limit	Months	Outfall
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	≤ 64 mg/L	Apr	001
Nitrogen, ammonia total [as N]	30-day average	≤ 43 mg/L	Jan	001
Nitrogen, ammonia total [as N]	30-day average	≤ 32 mg/L	Feb	001
Nitrogen, ammonia total [as N]	30-day average	≤ 64 mg/L	May	001
Nitrogen, ammonia total [as N]	30-day average	≤ 64 mg/L	Jun	001
Nitrogen, ammonia total [as N]	30-day average	≤ 64 mg/L	Jul	001
Nitrogen, ammonia total [as N]	30-day average	≤ 64 mg/L	Aug	001
Nitrogen, ammonia total [as N]	30-day average	≤ 42 mg/L	Dec	001
Nitrogen, ammonia total [as N]	30-day average	≤ 56 mg/L	Mar	001
Nitrogen, ammonia total [as N]	30-day average	≤ 43 mg/L	Sep	001
Nitrogen, ammonia total [as N]	30-day average	≤ 42 mg/L	Oct	001
Nitrogen, ammonia total [as N]	30-day average	≤ 64 mg/L	Nov	001
Nitrogen, ammonia total [as N]	30-day average	≤ 31 mg/L	Jan	001
Nitrogen, ammonia total [as N]	30-day average	≤ 31 mg/L	Feb	001
Nitrogen, ammonia total [as N]	30-day average	≤ 11 mg/L	Apr	001
Nitrogen, ammonia total [as N]	30-day average	≤ 13 mg/L	May	001
Nitrogen, ammonia total [as N]	30-day average	≤ 13 mg/L	Jun	001
Nitrogen, ammonia total [as N]	30-day average	≤ 12 mg/L	Jul	001
Nitrogen, ammonia total [as N]	30-day average	≤ 13 mg/L	Aug	001
Nitrogen, ammonia total [as N]	30-day average	≤ 13 mg/L	Sep	001
Nitrogen, ammonia total [as N]	30-day average	≤ 25 mg/L	Oct	001
Nitrogen, ammonia total [as N]	30-day average	≤ 52 mg/L	Nov	001
Nitrogen, ammonia total [as N]	30-day average	≤ 32 mg/L	Dec	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 180 mg/L	Apr	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 54 mg/L	Jan	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 49 mg/L	Feb	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 105 mg/L	May	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 340 mg/L	Jun	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 260 mg/L	Jul	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 210 mg/L	Aug	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 48 mg/L	Dec	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 65 mg/L	Mar	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 55 mg/L	Sep	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 44 mg/L	Oct	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 72 mg/L	Nov	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 54 mg/L	Jan	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 49 mg/L	Feb	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 21 mg/L	Apr	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 25 mg/L	May	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 26 mg/L	Jun	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 26 mg/L	Jul	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 29 mg/L	Aug	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 30 mg/L	Sep	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 33 mg/L	Oct	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 65 mg/L	Nov	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 32 mg/L	Dec	001
Nitrogen, ammonia total [as N]	rolling average	report only (mg/L)	Jan	001
Nitrogen, ammonia total [as N]	rolling average	report only (mg/L)	Feb	001
Nitrogen, ammonia total [as N]	rolling average	report only (mg/L)	Mar	001
Nitrogen, ammonia total [as N]	rolling average	report only (mg/L)	Apr	001
Nitrogen, ammonia total [as N]	rolling average	report only (mg/L)	May	001
Nitrogen, ammonia total [as N]	rolling average	report only (mg/L)	Jun	001
Nitrogen, ammonia total [as N]	rolling average	report only (mg/L)	Jul	001
Nitrogen, ammonia total [as N]	rolling average	report only (mg/L)	Aug	001
Nitrogen, ammonia total [as N]	rolling average	report only (mg/L)	Sep	001
Nitrogen, ammonia total [as N]	rolling average	report only (mg/L)	Oct	001
Nitrogen, ammonia total [as N]	rolling average	report only (mg/L)	Nov	001
Nitrogen, ammonia total [as N]	rolling average	report only (mg/L)	Dec	001
Nitrogen, inorganic total	daily maximum	≤ 138 mg/L	all year	001
Nitrogen, inorganic total	rolling average	report only (mg/L)	all year	001
Phosphorus, total [as P]	30-day average	report only (mg/L)	all year	001
Phosphorus, total [as P]	daily maximum	report only (mg/L)	all year	001
Iron, total recoverable	30-day average	report only (ug/L)	all year	001
Iron, total recoverable	30-day average	≤ 12667 ug/L	all year	001
Iron, total recoverable	30-day average	report only (ug/L)	all year	001
Iron, total recoverable	rolling average	report only (ug/L)	all year	001
Iron, total recoverable	rolling average	≤ 1956 ug/L	all year	001
Iron, dissolved [as Fe]	30-day average	report only (ug/L)	all year	001
Iron, dissolved [as Fe]	30-day average	≤ 3864 ug/L	all year	001
Aluminum, total recoverable	30-day average	report only (ug/L)	all year	001
Aluminum, total recoverable	daily maximum	report only (ug/L)	all year	001
Lead, total recoverable	30-day average	report only (ug/L)	all year	001
Lead, potentially dissolvd	30-day average	report only (ug/L)	all year	001
Lead, potentially dissolvd	daily maximum	report only (ug/L)	all year	001
Oil and grease	instantaneous maximum	≤ 10 mg/L	all year	001
Benzene	30-day average	report only (ug/L)	all year	001
Benzene	30-day average	≤ 30 ug/L	all year	001
Benzene	daily maximum	report only (ug/L)	all year	001
Benzene	daily maximum	≤ 73249 ug/L	all year	001
Benzene	rolling average	report only (ug/L)	all year	001
Benzene	rolling average	≤ 4.6 ug/L	all year	001
Anthracene	30-day average	report only (ug/L)	all year	001
Anthracene	30-day average	≤ 29023 ug/L	all year	001
Anthracene	rolling average	report only (ug/L)	all year	001
Anthracene	rolling average	≤ 4353 ug/L	all year	001
Benzo[b]fluoranthene	30-day average	report only (ug/L)	all year	001
Benzo[b]fluoranthene	30-day average	≤ .053 ug/L	all year	001
Benzo[b]fluoranthene	30-day average	report only (ug/L)	all year	001
Benzo[b]fluoranthene	rolling average	report only (ug/L)	all year	001
Benzo[b]fluoranthene	rolling average	≤ .0083 ug/L	all year	001
Benzo[k]fluoranthene	30-day average	report only (ug/L)	all year	001
Benzo[k]fluoranthene	30-day average	≤ .053 ug/L	all year	001
Benzo[k]fluoranthene	30-day average	report only (ug/L)	all year	001
Benzo[k]fluoranthene	rolling average	report only (ug/L)	all year	001
Benzo[k]fluoranthene	rolling average	≤ .0083 ug/L	all year	001
Benzo[a]pyrene	30-day average	report only (ug/L)	all year	001
Benzo[a]pyrene	30-day average	≤ .053 ug/L	all year	001
Benzo[a]pyrene	30-day average	report only (ug/L)	all year	001
Benzo[a]pyrene	rolling average	report only (ug/L)	all year	001
Benzo[a]pyrene	rolling average	≤ .0083 ug/L	all year	001
Chrysene	30-day average	report only (ug/L)	all year	001
Chrysene	30-day average	≤ .053 ug/L	all year	001
Chrysene	30-day average	report only (ug/L)	all year	001
Chrysene	rolling average	report only (ug/L)	all year	001
Chrysene	rolling average	≤ .0083 ug/L	all year	001
Fluoranthene	30-day average	report only (ug/L)	all year	001
Fluoranthene	30-day average	≤ 1797 ug/L	all year	001
Fluoranthene	daily maximum	report only (ug/L)	all year	001
Fluoranthene	daily maximum	≤ 55006 ug/L	all year	001
Fluoranthene	rolling average	report only (ug/L)	all year	001
Fluoranthene	rolling average	≤ 276 ug/L	all year	001
Fluorene	30-day average	report only (ug/L)	all year	001
Fluorene	30-day average	≤ 3870 ug/L	all year	001
Fluorene	30-day average	report only (ug/L)	all year	001
Fluorene	rolling average	report only (ug/L)	all year	001
Fluorene	rolling average	≤ 580 ug/L	all year	001
Indeno[1,2,3-cd]pyrene	30-day average	report only (ug/L)	all year	001
Indeno[1,2,3-cd]pyrene	30-day average	≤ .053 ug/L	all year	001
Indeno[1,2,3-cd]pyrene	30-day average	report only (ug/L)	all year	001
Indeno[1,2,3-cd]pyrene	rolling average	report only (ug/L)	all year	001
Indeno[1,2,3-cd]pyrene	rolling average	≤ .0083 ug/L	all year	001
Pyrene	30-day average	report only (ug/L)	all year	001
Pyrene	30-day average	≤ 2902 ug/L	all year	001
Pyrene	30-day average	report only (ug/L)	all year	001
Pyrene	rolling average	report only (ug/L)	all year	001
Pyrene	rolling average	≤ 442 ug/L	all year	001
Benzo[ghi]perylene	30-day average	report only (ug/L)	all year	001
Benzo[ghi]perylene	30-day average	≤ .053 ug/L	all year	001
Benzo[ghi]perylene	30-day average	report only (ug/L)	all year	001
Benzo[ghi]perylene	rolling average	report only (ug/L)	all year	001
Benzo[ghi]perylene	rolling average	≤ .0083 ug/L	all year	001
Benzo[a]anthracene	30-day average	report only (ug/L)	all year	001
Benzo[a]anthracene	30-day average	≤ .053 ug/L	all year	001
Benzo[a]anthracene	30-day average	report only (ug/L)	all year	001
Benzo[a]anthracene	rolling average	report only (ug/L)	all year	001
Benzo[a]anthracene	rolling average	≤ .0083 ug/L	all year	001
Dibenz[a,h]anthracene	30-day average	report only (ug/L)	all year	001
Dibenz[a,h]anthracene	30-day average	≤ .053 ug/L	all year	001
Dibenz[a,h]anthracene	30-day average	report only (ug/L)	all year	001
Dibenz[a,h]anthracene	rolling average	report only (ug/L)	all year	001
Dibenz[a,h]anthracene	rolling average	≤ .0083 ug/L	all year	001
Naphthalene	30-day average	report only (ug/L)	all year	001
Naphthalene	30-day average	≤ 1935 ug/L	all year	001
Naphthalene	30-day average	report only (ug/L)	all year	001
Naphthalene	daily maximum	report only (ug/L)	all year	001
Naphthalene	daily maximum	≤ 31787 ug/L	all year	001
Naphthalene	daily maximum	report only (ug/L)	all year	001
Naphthalene	rolling average	report only (ug/L)	all year	001
Naphthalene	rolling average	≤ 290 ug/L	all year	001
BTEX	daily maximum	report only (ug/L)	all year	001
BTEX	daily maximum	≤ 100 ug/L	all year	001
Flow, in conduit or thru treatment plant	30-day average	≤ .025 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	≤ .29 mg/L	all year	001
Chlorine, total residual	30-day average	report only (mg/L)	all year	001
Chlorine, total residual	instantaneous maximum	≤ .26 mg/L	all year	001
Chlorine, total residual	instantaneous maximum	≤ .26 mg/L	all year	001
Chlorine, total residual	rolling average	report only (mg/L)	all year	001
Chlorine, total residual	rolling average	≤ .023 mg/L	all year	001
E. coli	30-day geometric mean	report only (#/100mL)	all year	001
E. coli	maximum 7-day geometric mean	≤ 2700 #/100mL	all year	001
E. coli	rolling average	≤ 223 #/100mL	all year	001
Nonylphenol	30-day average	≤ 91 ug/L	all year	001
Nonylphenol	30-day average	report only (ug/L)	all year	001
Nonylphenol	30-day average	report only (ug/L)	all year	001
Nonylphenol	daily maximum	≤ 387 ug/L	all year	001
Nonylphenol	daily maximum	report only (ug/L)	all year	001
Nonylphenol	daily maximum	≤ 387 ug/L	all year	001
Nonylphenol	rolling average	report only (ug/L)	all year	001
Nonylphenol	rolling average	≤ 14 ug/L	all year	001
Solids, total dissolved	30-day average	report only (mg/L)	all year	001
Solids, total dissolved	daily maximum	report only (mg/L)	all year	001
Solids, total dissolved	30-day average	report only (mg/L)	all year	001
Solids, total dissolved	daily maximum	report only (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
Sulfate	30-day average	report only (ug/L)	all year	001
Sulfate	daily maximum	report only (ug/L)	all year	001
Oil and grease visual	instantaneous maximum	report only (abst=0;prst=1)	all year	001
LC50 Static Renewal 48Hr Acute Ceriodaphnia dubia	minimum value	report only (%)	all year	001
LC50 Static Renewal 48Hr Acute Ceriodaphnia dubia	minimum value	≥ 100 %	all year	001
LC50 Static Renewal 96Hr Acute Pimephales promelas	minimum value	report only (%)	all year	001
LC50 Static Renewal 96Hr Acute Pimephales promelas	minimum value	≥ 100 %	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

How strict are these limits?

Your permit document is the final word. As JSON: /api/v1/permits/CO0047457 · MCP: https://passage-data.com/mcp