Mason WWTP
345 N Jefferson St, Mason, MI 48854 · Ingham County · Publicly Owned Treatment Works
- Average flow
- 5.69 MGD
- Design flow
- —
- NPDES permit
- MI0020435
- Effective
- Permit expires
- October 2027
- Population served
- 6,235
- CWNS 2022
Mason WWTP is a publicly owned wastewater treatment works in Mason, Ingham County, Michigan treating an average of 5.69 million gallons per day, serving about 6,235 residents. It discharges under NPDES permit MI0020435 (effective), which expires in October 2027, with 31 recorded violations in the last three years.
Treatment technology
2 treatment structures and unit processes identified at Mason WWTP.
Available with a free Klarifi account
See the full treatment train at Mason WWTP: structures, unit processes and planned upgrades, with exact unit counts.
Compliance snapshot (last 3 years)
- Total violations
- 31
- Effluent violations
- 31
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 Mason WWTP in EPA's ICIS system.
- Formal actions
- 0
- none on record
- EPA inspections
- 1
- latest Jul 2004
No formal federal enforcement case is on record for this plant.
Full case history with a free Klarifi account
Every action against Mason WWTP with dates, milestones, violation types and EPA's complete case summaries, plus inspections and informal actions.
Capital improvement projects in Mason
Mason's capital improvement plan lists 113 water, sewer and wastewater line items worth $17M starting 2024–2029. The largest budgeted items are shown here.
All water and sewer capital projects in Mason →
| Project | Budget | Years |
|---|---|---|
| Advanced Metering Infrastructure and Meter Replacement (Water) | $1,120,000 | 2028–2029 |
| Advanced Metering Infrastructure and Meter Replacement (Water) | $1,120,000 | 2028–2029 |
| W. South Street: Lansing Street to US 127 (Gen Utilities) | $501,250 | 2028–2029 |
| W. South Street: Lansing Street to US 127 (Gen Utilities) | $501,250 | 2028–2029 |
| Office Building Remodel (Sanitary) | $500,000 | 2029–2030 |
Full project details — scope, funding source, engineering consultant and the decision-makers behind each project — are available in Klarifi, along with similar wastewater capital projects in other cities.
Key contacts
1 verified contact for Mason WWTP, with validated emails and direct phone numbers.
Unlock 1 verified contact
Names, validated emails and direct phone numbers for decision-makers at Mason WWTP, plus the full compliance history and discharge data.
Nearby wastewater treatment plants in Michigan
Holt · 7 mi away
2.47 MGD
East Lansing · 10 mi away
11.19 MGD
Leslie · 10 mi away
0.24 MGD
Williamston · 11 mi away
0.44 MGD
Dimondale · 12 mi away
0.21 MGD
Lansing · 13 mi away
13.64 MGD
Webberville · 15 mi away
0.8 MGD
Lansing · 16 mi away
4.67 MGD
Mason 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 April 4, 2025.
Wastewater terms: POTW · MGD · NPDES permit · Inflow and infiltration · Significant industrial user · WWTP · all terms