Nampa WWTP
340 W Railroad St, Nampa, ID 83687 · Canyon County · Publicly Owned Treatment Works
- Average flow
- 10.69 MGD
- Design flow
- 11.76 MGD
- NPDES permit
- ID0022063
- Administratively continued
- Permit expires
- October 2021
- Population served
- 100,200
- CWNS 2022
Nampa WWTP is a publicly owned wastewater treatment works in Nampa, Canyon County, Idaho treating an average of 10.69 million gallons per day against a permitted design capacity of 11.76 MGD, serving about 100,200 residents. It discharges under NPDES permit ID0022063 (administratively continued), which expires in October 2021, with 27 recorded violations in the last three years.
Treatment technology
2 treatment structures and unit processes identified at Nampa WWTP.
Available with a free Klarifi account
See the full treatment train at Nampa WWTP: structures, unit processes and planned upgrades, with exact unit counts.
Compliance snapshot (last 3 years)
- Total violations
- 27
- Effluent violations
- 1
Based on NPDES Discharge Monitoring Reports. Full violation history, parameters and discharge data available in the Klarifi platform.
EPA enforcement history
Federal civil enforcement cases, compliance inspections and informal actions recorded for Nampa WWTP in EPA's ICIS system.
- Formal actions
- 0
- none on record
- EPA inspections
- 1
- latest Jul 2006
No formal federal enforcement case is on record for this plant.
Full case history with a free Klarifi account
Every action against Nampa WWTP with dates, milestones, violation types and EPA's complete case summaries, plus inspections and informal actions.
Key contacts
7 verified contacts for Nampa WWTP, with validated emails and direct phone numbers.
Unlock 7 verified contacts (4 more than shown)
Names, validated emails and direct phone numbers for decision-makers at Nampa WWTP, plus the full compliance history and discharge data.
Nearby wastewater treatment plants in Idaho
Star · 8 mi away
1.52 MGD
Meridian · 8 mi away
1.3 MGD
Marsing · 12 mi away
—
Greenleaf · 13 mi away
0.06 MGD
Garden City · 13 mi away
50.91 MGD
Notus · 15 mi away
0.06 MGD
Wilder · 17 mi away
0.11 MGD
Homedale · 19 mi away
0.25 MGD
Nampa WWTP: frequently asked questions
Sources and methodology
Flow, permit and violation figures come from the EPA's ICIS-NPDES discharge monitoring records. Population served comes from the Clean Watersheds Needs Survey 2022. Treatment structures are identified by Klarifi's review of aerial imagery, and capital improvement projects are extracted from published municipal budget documents. Violations are counted over the last three years of monitoring reports.
Data refreshed October 26, 2026; facility record last updated March 4, 2025.
Wastewater terms: POTW · MGD · NPDES permit · Inflow and infiltration · Filter press · FOG · all terms