Union Pacific Railroad Company — NPDES permit WY0032590: limits, due date and EPA's record

Railroads, Line-Haul Operating, major discharger, Laramie, Wyoming. NPDES permit WY0032590, in force until Jul 31, 2030. Last 12 months: no values over a limit. Source: EPA ECHO, Oct 22, 2026.

Limits in force (21)

Parameter	Statistic	Limit	Months	Outfall
pH	instantaneous minimum	≥ 6.5 SU	all year	001
pH	instantaneous maximum	≤ 9 SU	all year	001
Arsenic, total recoverable	daily maximum	≤ 20 ug/L	all year	001
Pentachlorophenol	daily maximum	≤ 1 ug/L	all year	001
Solids, total dissolved	daily maximum	≤ 9600 mg/L	all year	001
Flow	daily maximum	report only (MGD)	all year	001
Flow	monthly average	report only (MGD)	all year	001
Flow	daily maximum	report only (MGD)	all year	001
Flow	value	≤ .11 gal/d	all year	001
Pass/Fail Static Renewal 7 Day Chronic Ceriodaphnia dubia	7-day maximum	≤ 0 pass=0;fail=1	all year	001
Pass/Fail Static Renewal 7Day Chronic Pimephales promelas	7-day maximum	≤ 0 pass=0;fail=1	all year	001
pH	instantaneous minimum	≥ 6.5 SU	all year	002
pH	instantaneous maximum	≤ 9 SU	all year	002
Arsenic, total recoverable	daily maximum	≤ 20 ug/L	all year	002
Pentachlorophenol	daily maximum	≤ 1 ug/L	all year	002
Solids, total dissolved	daily maximum	≤ 9600 mg/L	all year	002
Flow	daily maximum	report only (MGD)	all year	002
Flow	monthly average	report only (MGD)	all year	002
Flow	daily maximum	report only (MGD)	all year	002
Pass/Fail Static Renewal 7Day Chronic Pimephales promelas	7-day maximum	≤ 0 pass=0;fail=1	all year	002
Pass/Fail Sub-Lethal Static Renewal 7 Day Chronic Ceriodaphnia dubia	7-day maximum	≤ 0 pass=0;fail=1	all year	002

How strict are these limits?

Your permit document is the final word. As JSON: /api/v1/permits/WY0032590 · MCP: https://passage-data.com/mcp