NW Harris County Mud 9 WWTP
11023 Regency Green Dr, Cypress, TX 77429 · Harris County · Publicly Owned Treatment Works
- Average flow
- 0.85 MGD
- Design flow
- 0.95 MGD
- NPDES permit
- TX0075221
- Effective
- Permit expires
- June 2029
- Population served
- 5,500
- CWNS 2022
NW Harris County Mud 9 WWTP is a publicly owned wastewater treatment works in Cypress, Harris County, Texas treating an average of 0.85 million gallons per day against a permitted design capacity of 0.95 MGD, serving about 5,500 residents. It discharges under NPDES permit TX0075221 (effective), which expires in June 2029, with 20 recorded violations in the last three years. EPA has recorded 1 formal enforcement action naming the plant, the latest in December 2025.
Treatment technology
One treatment structure or unit process identified at NW Harris County Mud 9 WWTP.
Available with a free Klarifi account
See the full treatment train at NW Harris County Mud 9 WWTP: structures, unit processes and planned upgrades, with exact unit counts.
Compliance snapshot (last 3 years)
- Total violations
- 20
- Effluent violations
- 20
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 NW Harris County Mud 9 WWTP in EPA's ICIS system.
- Formal actions
- 1
- 1 since FY2020
- Compliance actions
- $150,000
- required by EPA orders
- EPA inspections
- 0
- none on record
Latest case · Dec 2025
Northwest Harris County MUD #9
Administrative order · CWA, NPDES Permit Violations · Unilateral Administrative Order Without Adjudication · Compliance actions $150,000
EPA's description of the case:
“On December 9, 2025, EPA Region 6 issued an Administrative Order (AO) under its authority pursuant to Section 309 of the Clean Water Act to Northwest Harris County MUD #9 WWTF. The AO was issued in…”
Unlock EPA's full description by creating a free account on Klarifi. Create a free account →
Source: EPA ECHO, civil enforcement case 06-2026-1716.
Full case history with a free Klarifi account
Every action against NW Harris County Mud 9 WWTP with dates, milestones, violation types and EPA's complete case summaries, plus inspections and informal actions.
Key contacts
Decision-makers at NW Harris County Mud 9 WWTP.
No verified contacts on file yet
Klarifi verifies plant and municipal decision-makers continuously. Start a free trial to browse contacts at nearby plants and flag this one for verification.
Nearby wastewater treatment plants in Texas
Houston · 1 mi away
0.67 MGD
Houston · 1 mi away
0.59 MGD
Houston · 2 mi away
2.39 MGD
Houston · 2 mi away
0.21 MGD
Houston · 2 mi away
0.99 MGD
Houston · 2 mi away
0.53 MGD
Houston · 2 mi away
0.77 MGD
Houston · 2 mi away
1.12 MGD
NW Harris County Mud 9 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 9, 2025.
Wastewater terms: POTW · MGD · NPDES permit · Inflow and infiltration · Lift station · Sludge dewatering · all terms