What is the address of Mason WWTP?

The address on the plant’s EPA facility record is 2950 Birch Dr, Mason City, IA 50401, in Cerro Gordo County. Its coordinates are 43.1376, -93.1554. For some plants the record holds the utility’s mailing address rather than the plant gate.

How much wastewater does Mason WWTP treat?

Mason WWTP treats an average of 5.13 MGD.

What treatment technology does Mason WWTP use?

Klarifi has identified 4 treatment structures and unit processes at the Mason City facility. The full treatment train, with exact unit counts, is shown in Klarifi with a free account.

What is the NPDES permit for Mason WWTP?

The facility discharges under NPDES permit IA0077305, currently effective, expiring May 2029.

Is Mason WWTP in compliance?

Discharge monitoring reports show 6 violations at Mason WWTP in the last three years, 6 of them effluent limit exceedances. The full history is available in Klarifi.

Who operates Mason WWTP and how do I contact them?

Mason WWTP is a publicly owned treatment works in Mason City, Iowa. Klarifi lists 5 verified decision-maker contacts for this facility, available with a free trial.

Try for free Log in

Mason WWTP

2950 Birch Dr, Mason City, IA 50401 · Cerro Gordo County · Publicly Owned Treatment Works

Average flow: 5.13 MGD

Design flow: —

NPDES permit: IA0077305; Effective

Permit expires: May 2029

Population served: 30,353; CWNS 2022

Mason WWTP is a publicly owned wastewater treatment works in Mason City, Cerro Gordo County, Iowa treating an average of 5.13 million gallons per day, serving about 30,353 residents. It discharges under NPDES permit IA0077305 (effective), which expires in May 2029, with 6 recorded violations in the last three years.

Treatment technology

4 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.

Create a free account

Compliance snapshot (last 3 years)

Total violations: 6

Effluent violations: 6

Based on NPDES Discharge Monitoring Reports. Full violation history, parameters and discharge data available in the Klarifi platform.

Key contacts

5 verified contacts for Mason WWTP, with validated emails and direct phone numbers.

Unlock 5 verified contacts (2 more than shown)

Names, validated emails and direct phone numbers for decision-makers at Mason WWTP, plus the full compliance history and discharge data.

Try Klarifi free

Nearby wastewater treatment plants in Iowa

Rock Falls WWTP

Rock Falls · 6 mi away

—

Plymouth City Of STP

Plymouth · 7 mi away

0.12 MGD

Nora Springs City Of STP

Nora Springs · 8 mi away

0.13 MGD

Manly WWTP

Manly · 10 mi away

0.27 MGD

Rockwell WWTP

Rockwell · 12 mi away

0.17 MGD

Rudd WWTP

Rudd · 12 mi away

—

Rockford WWTP

Rockford · 13 mi away

0.29 MGD

Grafton City Of STP

Grafton · 13 mi away

—

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 March 20, 2025.

Wastewater terms: POTW · MGD · NPDES permit · Inflow and infiltration · Significant industrial user · WWTP · all terms

Try Klarifi for free

Create your own trial account and explore how Klarifi can help you.

Try for free