City of Mason

Published drinking-water records and contacts for City of Mason. System MI0004170. Review sources and dates; not a real-time water assessment.

System ID: MI0004170
State or territory: MI
Published population served: 8252
System type (source code): CWS

Published records and dates

PFAS / lithium (EPA UCMR 5): 120 — 2023-01-24 – 2023-07-19
Lead and copper monitoring summaries: 67 — 1992-06-02 – 2025-12-31
Michigan EGLE PFAS compliance sampling: 112 — 2020-10-05 – 2025-04-23

Missing records here do not mean the provider did not test. Published records are not a real-time assessment of your tap water.

Published testing results

Selected recent records are shown below. Different sampling locations and dates are not interchangeable. These excerpts are not a complete testing history.

“<” means below the stated reporting limit, not zero. A reported measurement alone is not a safety verdict. Read an example

EPA UCMR 5 — most recent imported sample per substance
Substance	Published result	Reporting limit	Sample date	Sampling location
11Cl-PF3OUdS	< 0.005 µg/L	0.005 µg/L	2023-07-19	MASON, CITY OF / TP003
4:2 FTS	< 0.003 µg/L	0.003 µg/L	2023-07-19	MASON, CITY OF / TP003
6:2 FTS	< 0.005 µg/L	0.005 µg/L	2023-07-19	MASON, CITY OF / TP008
8:2 FTS	< 0.005 µg/L	0.005 µg/L	2023-07-19	MASON, CITY OF / TP008
9Cl-PF3ONS	< 0.002 µg/L	0.002 µg/L	2023-07-19	MASON, CITY OF / TP008
ADONA	< 0.003 µg/L	0.003 µg/L	2023-07-19	MASON, CITY OF / TP008
HFPO-DA	< 0.005 µg/L	0.005 µg/L	2023-07-19	MASON, CITY OF / TP003
NEtFOSAA	< 0.005 µg/L	0.005 µg/L	2023-07-19	MASON, CITY OF / TP003
NFDHA	< 0.02 µg/L	0.02 µg/L	2023-07-19	MASON, CITY OF / TP003
NMeFOSAA	< 0.006 µg/L	0.006 µg/L	2023-07-19	MASON, CITY OF / TP008
PFBA	< 0.005 µg/L	0.005 µg/L	2023-07-19	MASON, CITY OF / TP008
PFBS	< 0.003 µg/L	0.003 µg/L	2023-07-19	MASON, CITY OF / TP003
PFDA	< 0.003 µg/L	0.003 µg/L	2023-07-19	MASON, CITY OF / TP008
PFDoA	< 0.003 µg/L	0.003 µg/L	2023-07-19	MASON, CITY OF / TP008
PFEESA	< 0.003 µg/L	0.003 µg/L	2023-07-19	MASON, CITY OF / TP008
PFHpA	< 0.003 µg/L	0.003 µg/L	2023-07-19	MASON, CITY OF / TP003
PFHpS	< 0.003 µg/L	0.003 µg/L	2023-07-19	MASON, CITY OF / TP008
PFHxA	< 0.003 µg/L	0.003 µg/L	2023-07-19	MASON, CITY OF / TP008
PFHxS	< 0.003 µg/L	0.003 µg/L	2023-07-19	MASON, CITY OF / TP008
PFMBA	< 0.003 µg/L	0.003 µg/L	2023-07-19	MASON, CITY OF / TP008
PFMPA	< 0.004 µg/L	0.004 µg/L	2023-07-19	MASON, CITY OF / TP003
PFNA	< 0.004 µg/L	0.004 µg/L	2023-07-19	MASON, CITY OF / TP003
PFOA	< 0.004 µg/L	0.004 µg/L	2023-07-19	MASON, CITY OF / TP008
PFOS	< 0.004 µg/L	0.004 µg/L	2023-07-19	MASON, CITY OF / TP008
PFPeA	< 0.003 µg/L	0.003 µg/L	2023-07-19	MASON, CITY OF / TP003
PFPeS	< 0.004 µg/L	0.004 µg/L	2023-07-19	MASON, CITY OF / TP008
PFTA	< 0.008 µg/L	0.008 µg/L	2023-07-19	MASON, CITY OF / TP008
PFTrDA	< 0.007 µg/L	0.007 µg/L	2023-07-19	MASON, CITY OF / TP003
PFUnA	< 0.002 µg/L	0.002 µg/L	2023-07-19	MASON, CITY OF / TP008
lithium	< 9 µg/L	9 µg/L	2023-07-19	MASON, CITY OF / TP003

Download all EPA UCMR 5 records (CSV)

Lead and copper: 90th-percentile summaries

These describe a monitoring period across sampled locations, not the result at your home. How to read the 90th percentile

Eight most recent imported monitoring summaries
Substance	Published 90th percentile	Monitoring period	Source quarter
Lead (PB90)	0.0017 mg/L	2025-01-01 – 2025-12-31	2026Q3
Lead (PB90)	0.001 mg/L	2024-01-01 – 2024-12-31	2026Q3
Lead (PB90)	0.002 mg/L	2023-01-01 – 2023-12-31	2026Q3
Lead (PB90)	0.0033 mg/L	2022-01-01 – 2022-12-31	2026Q3
Lead (PB90)	0.0033 mg/L	2022-01-01 – 2022-12-31	2026Q3
Lead (PB90)	0.003 mg/L	2021-01-01 – 2021-12-31	2026Q3
Lead (PB90)	0.003 mg/L	2021-01-01 – 2021-12-31	2026Q3
Lead (PB90)	0.002 mg/L	2020-07-01 – 2020-12-31	2026Q3

Twelve most recent imported state laboratory records
Substance	Published result	Sample date	Location / source
PFHxA	< 2 ppt	2025-04-23	TP003 / Michigan EGLE PFAS compliance sampling
PFHxS	< 2 ppt	2025-04-23	TP003 / Michigan EGLE PFAS compliance sampling
PFHxS	< 2 ppt	2025-04-23	TP008 / Michigan EGLE PFAS compliance sampling
PFBS	< 2 ppt	2025-04-23	TP003 / Michigan EGLE PFAS compliance sampling
PFNA	< 2 ppt	2025-04-23	TP008 / Michigan EGLE PFAS compliance sampling
PFBS	< 2 ppt	2025-04-23	TP008 / Michigan EGLE PFAS compliance sampling
PFOA	< 2 ppt	2025-04-23	TP008 / Michigan EGLE PFAS compliance sampling
PFHxA	< 2 ppt	2025-04-23	TP008 / Michigan EGLE PFAS compliance sampling
PFOA	< 2 ppt	2025-04-23	TP003 / Michigan EGLE PFAS compliance sampling
HFPO-DA	< 2 ppt	2025-04-23	TP003 / Michigan EGLE PFAS compliance sampling
PFOS	< 2 ppt	2025-04-23	TP003 / Michigan EGLE PFAS compliance sampling
PFOS	< 2 ppt	2025-04-23	TP008 / Michigan EGLE PFAS compliance sampling

State sampling points can include untreated water. Publisher qualifiers and units are retained; consult the full source notes before interpreting a record.

Download state records with source notes (CSV)

Published compliance history

5 imported records. Status is as recorded in the source; historical records are not current advisories. Missing records do not establish that no violations occurred.

Twenty most recent imported compliance records
Rule / record	Period	Recorded status	Health-based (EPA classification)	Source quarter
Consumer Confidence Rule / Consumer Confidence Report Inadequate Reporting	2023-07-01 – —	Resolved	No	2026Q3
Stage 2 Disinfectants and Disinfection Byproducts Rule / Monitoring and Reporting (DBP)	2023-01-01 – 2023-12-31	Resolved	No	2026Q3
Stage 2 Disinfectants and Disinfection Byproducts Rule / Monitoring and Reporting (DBP)	2023-01-01 – 2023-12-31	Resolved	No	2026Q3
Radionuclides and Revised Rad Rule / Monitoring, Regular	2022-01-01 – 2022-03-31	Resolved	No	2026Q3
Consumer Confidence Rule / Consumer Confidence Report Complete Failure to Report	2021-07-01 – —	Resolved	No	2026Q3

Source dates and refresh checks

A refresh check is not a sample date. Publication periods, sample dates and checks are shown separately.

EPA SDWIS lead/copper summaries and service areas — source period: — – —; last checked: 2026-10-17
EPA SDWIS contacts and compliance records — source period: — – —; last checked: 2026-10-17
EPA UCMR 5 sample results — source period: 2023-01-03 – 2026-06-17; last checked: 2026-10-17
Michigan EGLE PFAS compliance sampling — last successful check: 2026-10-14

Administrative contact (EPA filing)

Rewerts, Jeff: 517-290-5681

An administrative filing contact may not be a customer-service line. Confirm current contact details with the provider.

Official state resources · How to read these records