Washington County Water Quality

Name: Washington County Water Quality Data (2026)
Creator: PurityMap
License: https://creativecommons.org/licenses/by/4.0/

Washington County, Ohio: one city report built from EPA and utility records. A county has many suppliers; each city shows the system that serves it.

Find my system Open on the map Private wells in Washington County

Across the county's systems

Highest result for each contaminant

One row per contaminant: the highest result any system in the county reported, against its limit. Open a row for the systems behind it.

Perfluorooctanesulfonic acid (PFOS)MARIETTA CITY PWS4.0 ng/L federal MCL (2024) · US EPA5.6 ng/L

MARIETTA CITY PWS5.6 ng/LSample date: 2024-11-05 to 2025-06-17

Perfluorooctanoic acid (PFOA)MARIETTA CITY PWS4.0 ng/L federal MCL (2024) · US EPA5.2 ng/L

MARIETTA CITY PWS5.2 ng/LSample date: 2024-11-05 to 2025-06-17

Lead (90th percentile)MARIETTA CITY PWS15 µg/L federal action level · US EPA0.7 µg/L

MARIETTA CITY PWS0.7 µg/LMonitoring period: 2026–2026 (still open)

Perfluorobutanesulfonic acid (PFBS)MARIETTA CITY PWS2,000 ng/L EPA health advisory (screening, not a legal limit) · US EPA4.7 ng/L

MARIETTA CITY PWS4.7 ng/LSample date: 2024-11-05 to 2025-06-17

27 substances tested, none detected in this systemShow

Tested in this system: MARIETTA CITY PWS

11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS)
1H, 1H, 2H, 2H-perfluorodecane sulfonic acid (8:2 FTS)
1H, 1H, 2H, 2H-perfluorohexane sulfonic acid (4:2 FTS)
1H, 1H, 2H, 2H-perfluorooctane sulfonic acid (6:2 FTS)
4,8-Dioxa-3H-perfluorononanoic acid (ADONA)
9-Chlorohexadecafluoro-3-oxanone-1-sulfonic acid (9Cl-PF3ONS)
Hexafluoropropylene oxide dimer acid (HFPO-DA) (GenX chemicals)
Lithium
N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA)
N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA)
Nonafluoro-3,6-dioxaheptanoic acid (NFDHA)
Perfluoro (2-ethoxyethane) sulfonic acid (PFEESA)
Perfluoro-3-methoxypropanoic acid (PFMPA)
Perfluoro-4-methoxybutanoic acid (PFMBA)
Perfluorobutanoic acid (PFBA)
Perfluorodecanoic acid (PFDA)
Perfluorododecanoic acid (PFDoA)
Perfluoroheptanesulfonic acid (PFHpS)
Perfluoroheptanoic acid (PFHpA)
Perfluorohexanesulfonic acid (PFHxS)
Perfluorohexanoic acid (PFHxA)
Perfluorononanoic acid (PFNA)
Perfluoropentanesulfonic acid (PFPeS)
Perfluoropentanoic acid (PFPeA)
Perfluorotetradecanoic acid (PFTA)
Perfluorotridecanoic acid (PFTrDA)
Perfluoroundecanoic acid (PFUnA)

1 city

Cities ranked by the records

1
MariettaMARIETTA CITY PWS
PFAS sample above a limitLead below action level
Open city report →

Showing 1 of 1 cities · scores are system-level, not tap tests

Ranked by the Purity Score of each city's main water system, highest first. Scores belong to water systems; there is no county score. The score is computed only from contaminants measured in the published EPA record, so this ranks the record, not which city's water is safest. How the score works.

PFAS in Washington County1 of 1 city report had a PFAS sample above a 2024 EPA limit

Marietta5.6 ng/L

4.0 ng/L federal MCL · PFOS, ng/LPFAS in Ohio

Lead

0of 1 city above the 15 µg/L action level

Based on each system's 90th-percentile result. Lead from household plumbing isn't in this record.

Lead in Ohio

Who supplies the county

Largest water systems

MariettaMARIETTA CITY PWS · OH8400412
18,707 served

Questions

Frequently asked

How does Washington County tap water compare across cities?

PurityMap ranks 1 city in Washington County by the Purity Score of each city's main water system, computed only from contaminants measured in the published EPA record. Scores belong to water systems, not to cities. The highest published score is Marietta's main water system: MARIETTA CITY PWS · PWSID OH8400412 · Purity Score 69 (Fair) · Confidence: moderate · Assessed at the water-system level. The ranking compares the records, not which city's water is safest, and your own tap can differ with household plumbing.

How many Washington County cities had a PFAS sample above a 2024 EPA limit?

1 of 1 Washington County city report had a PFAS sample above a 2024 EPA limit in EPA's UCMR 5 testing, including Marietta (PFOS 5.6 ng/L). That limit is judged on a yearly average, and water systems have until 2029 to meet it, so a single sample is not a violation. PFAS were detected at any level in 1.

Is there lead in Washington County tap water?

Utilities report lead as a 90th-percentile result from home taps. 1 of 1 Washington County cities reported a value above zero, and none was above the 15 µg/L federal action level. Lead usually comes from a building's own pipes and fixtures, so only a test at your tap tells you what you drink.

Next step

Follow Washington County's water

Get an email when a city record in the county changes. Or go straight to the filters certified for what was found here.

Filters certified for PFAS

FOLLOW THIS COUNTY

Record changes only

We email when places in Washington County get new results. Unsubscribe any time.

Follow Washington County's water →