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MASON, CITY OF

PWS ID: MI0004170 · MASON, Michigan 48854

MASON, CITY OF serves 8,252 people in MASON, Michigan using Groundwater water sources. It has 54 recorded EPA violations, including 27 health-based violations. PFAS "forever chemicals" were detected in UCMR5 testing (1 compound found).

Water Quality Snapshot: MASON, CITY OF

MASON, CITY OF is a local-owned community water system that delivers drinking water to 8,252 residents in MASON, Michigan (Ingham County) through 3,200 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 54 total violations for this system , of which 27 (50%) are health-based — meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 19 monitoring and reporting violations are on file. The most recent violation on record dates to 2023.

The most frequently cited contaminant at this system is Combined Radium (-226 and -228), recorded in 19 violations (MCL, health-based). Under EPA's UCMR5 PFAS monitoring program, 1 PFAS compound was detected in samples collected from this system, with a maximum reported concentration of 15 ppt. PFAS are persistent synthetic chemicals linked to health effects at very low exposure levels.

Across Michigan, EPA tracks 10,959 public water systems serving 9,098,093 people, with 255,201 cumulative violations and 31,467 health-based violations on record. About 86% of systems in the state carry at least one violation, and state-wide the average per system is 23.3 violations. MASON, CITY OF's 54 violations sit above the Michigan average. Statewide, 87 of 318 UCMR5-tested systems have reported PFAS detections (27.4%). All figures above are sourced directly from EPA SDWIS and UCMR5 public data releases and are updated as EPA publishes new reporting cycles.

PFAS Detected

1 PFAS "forever chemicals" detected in testing under EPA's UCMR5 monitoring program.

Population Served
8,252
Total Violations
54
Health-Based Violations
27
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Local
Connections
3,200
County
Ingham
School/Daycare
No
MCL Violations
27
Monitoring Violations
19
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Combined Radium (-226 and -228) MCL 19 2005
Coliform (TCR) MCL 8 2003
Gross Alpha, Excl. Radon and U MR 4 1999
Combined Radium (-226 and -228) MR 4 2022
TTHM MR 4 2023
Total Haloacetic Acids (HAA5) MR 4 2023
Consumer Confidence Rule Other 4 2023
Coliform (TCR) MR 3 1998

PFAS Testing Results (UCMR5)

Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 2 of 120 samples detected PFAS.

Contaminant Date Result MRL Status
PFPeS 7/19/2023 <0.004 µg/L 0.004 µg/L Not Detected
NFDHA 7/19/2023 <0.02 µg/L 0.02 µg/L Not Detected
9Cl-PF3ONS 7/19/2023 <0.002 µg/L 0.002 µg/L Not Detected
PFHpS 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFHxA 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFUnA 7/19/2023 <0.002 µg/L 0.002 µg/L Not Detected
11Cl-PF3OUdS 7/19/2023 <0.005 µg/L 0.005 µg/L Not Detected
ADONA 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
HFPO-DA 7/19/2023 <0.005 µg/L 0.005 µg/L Not Detected
PFMPA 7/19/2023 <0.004 µg/L 0.004 µg/L Not Detected
8:2 FTS 7/19/2023 <0.005 µg/L 0.005 µg/L Not Detected
4:2 FTS 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFBA 7/19/2023 <0.005 µg/L 0.005 µg/L Not Detected
PFDoA 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFMBA 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
6:2 FTS 7/19/2023 <0.005 µg/L 0.005 µg/L Not Detected
lithium 7/19/2023 <9 µg/L 9 µg/L Not Detected
PFBS 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFDA 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFTrDA 7/19/2023 <0.007 µg/L 0.007 µg/L Not Detected
NMeFOSAA 7/19/2023 <0.006 µg/L 0.006 µg/L Not Detected
PFTA 7/19/2023 <0.008 µg/L 0.008 µg/L Not Detected
PFPeA 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFEESA 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFHpA 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFHxS 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFNA 7/19/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFOS 7/19/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFOA 7/19/2023 <0.004 µg/L 0.004 µg/L Not Detected
NEtFOSAA 7/19/2023 <0.005 µg/L 0.005 µg/L Not Detected
PFDA 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFOA 7/19/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFOS 7/19/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFNA 7/19/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFHxS 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFBS 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
lithium 7/19/2023 15.0000 µg/L 9 µg/L Detected
PFDoA 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
HFPO-DA 7/19/2023 <0.005 µg/L 0.005 µg/L Not Detected
NMeFOSAA 7/19/2023 <0.006 µg/L 0.006 µg/L Not Detected
PFHpA 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
4:2 FTS 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFHpS 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFPeS 7/19/2023 <0.004 µg/L 0.004 µg/L Not Detected
NFDHA 7/19/2023 <0.02 µg/L 0.02 µg/L Not Detected
PFEESA 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFMBA 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFPeA 7/19/2023 <0.003 µg/L 0.003 µg/L Not Detected
9Cl-PF3ONS 7/19/2023 <0.002 µg/L 0.002 µg/L Not Detected
8:2 FTS 7/19/2023 <0.005 µg/L 0.005 µg/L Not Detected

Verify This Water System

The figures above are aggregated from EPA's public databases. To verify the underlying records — or to file a complaint, request a Consumer Confidence Report, or check current monitoring status — go directly to the federal and state regulators that enforce the Safe Drinking Water Act for MASON, CITY OF.

Federal Source of Truth

EPA SDWIS — Federal Reports

EPA's Safe Drinking Water Information System (SDWIS) holds the federal compliance record for every regulated public water system. Open the system-level report by PWS ID:

View PWS ID MI0004170 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

Michigan Drinking Water Authority

Michigan EGLE — Drinking Water and Environmental Health Division is the primacy agency that licenses and inspects MASON, CITY OF under EPA-delegated authority.

Open MI regulator portal

Source: Michigan EGLE — Drinking Water and Environmental Health Division

Violation Timeline

Each row links to the EPA SDWIS public record for verification. Cross-reference the contaminant code on EPA's federal report to see violation dates, return-to-compliance status, and enforcement actions.

Year (latest) Contaminant Category Count EPA Record
2023 TTHM MR 4 SDWIS / MI0004170 / 2950
2023 Total Haloacetic Acids (HAA5) MR 4 SDWIS / MI0004170 / 2456
2023 Consumer Confidence Rule Other 4 SDWIS / MI0004170 / 7000
2022 Combined Radium (-226 and -228) MR 4 SDWIS / MI0004170 / 4010
2005 Combined Radium (-226 and -228) MCL 19 SDWIS / MI0004170 / 4010
2003 Coliform (TCR) MCL 8 SDWIS / MI0004170 / 3100
1999 Gross Alpha, Excl. Radon and U MR 4 SDWIS / MI0004170 / 4000
1998 Coliform (TCR) MR 3 SDWIS / MI0004170 / 3100

How MASON, CITY OF Compares

Cross-reference this system's record against state averages and the federal MCL framework for context.

Metric MASON, CITY OF Michigan avg Federal benchmark
Total violations 54 23.3 SDWA compliance — any non-zero count is a recorded breach
Health-based violations 27 2.9 Indicates a contaminant exceeded a federal MCL
PFAS detection 1 compound 27.4% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 8,252 830 Sizing context for compliance burden

Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 10,959 regulated public water systems in Michigan.

Federal MCL reference — Safe Drinking Water Act thresholds ▼
Contaminant Federal MCL / Action Level Note
Lead 0 mg/L (Action Level: 0.015 mg/L) Lead and Copper Rule treatment technique
Arsenic 0.010 mg/L (10 ppb) Health-based MCL since 2006
Total Coliform Treatment technique (RTCR) Indicator organism, monitoring trigger
PFOA / PFOS (PFAS) 4.0 ppt each (final 2024 rule) Compliance deadline 2029
Nitrate (as N) 10 mg/L Acute health risk for infants

Frequently Asked Questions

Is MASON, CITY OF water safe to drink? ▼
MASON, CITY OF (PWS ID: MI0004170) has 54 recorded violations in the EPA SDWIS database. PFAS contamination has been detected in UCMR5 testing, with 1 PFAS compound found. This system serves 8,252 people using Groundwater sources.
How many people does MASON, CITY OF serve? ▼
MASON, CITY OF serves 8,252 people in MASON, Michigan. It is a Local-owned system using Groundwater water sources with 3,200 service connections.
What type of violations does MASON, CITY OF have? ▼
MASON, CITY OF has 54 total violations: 27 health-based violations (MCL exceedances or treatment failures), 19 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in MASON, CITY OF water? ▼
Yes. UCMR5 testing detected 1 PFAS compound in MASON, CITY OF's water supply: lithium. PFAS are persistent "forever chemicals" that do not break down in the environment.
What water source does MASON, CITY OF use? ▼
MASON, CITY OF uses Groundwater as its primary water source. It is classified as a Community Water System (CWS), serving residential populations year-round.
Where does this data come from? ▼
All data comes from the EPA Safe Drinking Water Information System (SDWIS) and the UCMR5 PFAS monitoring program. SDWIS tracks compliance for all public water systems regulated under the Safe Drinking Water Act.

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Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025. PFAS data from EPA UCMR5 monitoring program (2023-2025). This data is provided for informational purposes only.

Read our methodology — how this data is sourced, computed, and verified.

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Data sourced from $official public datasets. See our methodology for details. Retrieved and formatted by PlainWater Editorial