Is Johnstown, OH Tap Water Safe? Quality & Contaminants

What was found in Johnstown's water

The level at the city's main supplier, the highest level anywhere in the city, the EPA limit for each, and where every figure comes from.

Contaminant	Level vs EPA limit	Suppliers	Source
Fluoride	529 µg/L 13% of the EPA limit 4000 µg/L Main supplier: JOHNSTOWN CITY PWS · 5,200 people · 2018 Highest in the city: 994 µg/L — GREEN MEADOWS MHP · 51 people · 2018	2/2	SYR4
Nitrate	240 µg/L 2.4% of the EPA limit 10000 µg/L Main supplier: JOHNSTOWN CITY PWS · 5,200 people · 2019	1/2	SYR4
Nitrate-Nitrite	230 µg/L 2.3% of the EPA limit 10000 µg/L Main supplier: JOHNSTOWN CITY PWS · 5,200 people · 2019	1/2	SYR4
Copper	225.3 µg/L 17% of the EPA limit 1300 µg/L Main supplier: JOHNSTOWN CITY PWS · 5,200 people · 2018	2/2	SYR4
TTHM	59.68 µg/L 75% of the EPA limit 80 µg/L Main supplier: JOHNSTOWN CITY PWS · 5,200 people · 2019	2/2	SYR4
Barium	38.98 µg/L 1.9% of the EPA limit 2000 µg/L Highest in the city: GREEN MEADOWS MHP · 51 people · 2018	1/2	SYR4
Dibromochloromethane	21.15 µg/L No EPA limit set Main supplier: JOHNSTOWN CITY PWS · 5,200 people · 2019	2/2	SYR4
Bromodichloromethane	18.32 µg/L No EPA limit set Main supplier: JOHNSTOWN CITY PWS · 5,200 people · 2019	2/2	SYR4
Lithium	18 µg/L No EPA limit set Main supplier: JOHNSTOWN CITY PWS · 5,200 people · 2024	1/2	UCMR-5
Lead	13 µg/L 87% of the EPA limit 15 µg/L Main supplier: JOHNSTOWN CITY PWS · 5,200 people · 2018	1/2	SYR4
Chloroform	11.24 µg/L No EPA limit set Main supplier: JOHNSTOWN CITY PWS · 5,200 people · 2019	2/2	SYR4
Total Haloacetic Acids (HAA5)	10.52 µg/L 18% of the EPA limit 60 µg/L Main supplier: JOHNSTOWN CITY PWS · 5,200 people · 2019	2/2	SYR4
Bromoform	9.84 µg/L No EPA limit set Main supplier: JOHNSTOWN CITY PWS · 5,200 people · 2019	2/2	SYR4
Dibromoacetic Acid	5.225 µg/L No EPA limit set Main supplier: JOHNSTOWN CITY PWS · 5,200 people · 2019	2/2	SYR4
Dichloroacetic Acid	3.905 µg/L No EPA limit set Main supplier: JOHNSTOWN CITY PWS · 5,200 people · 2019	2/2	SYR4
Trichloroacetic Acid	1.1 µg/L No EPA limit set Main supplier: JOHNSTOWN CITY PWS · 5,200 people · 2019 Highest in the city: 3.73 µg/L — GREEN MEADOWS MHP · 51 people · 2019	2/2	SYR4
Di(2-ethylhexyl) Phthalate	0.7500 µg/L 13% of the EPA limit 6 µg/L Highest in the city: GREEN MEADOWS MHP · 51 people · 2017	1/2	SYR4
Lead	0.0020 mg/L 13% of the EPA limit 0.0150 mg/L Main supplier: JOHNSTOWN CITY PWS · 5,200 people · 2024	2/2	LCR

Each bar shows the measured level as a share of the EPA limit: green is well under, amber is close to it, red is over. For lead and copper the limit applies to exactly the 90th-percentile figure shown, so red there means a real exceedance. For everything else the limit applies to a running annual average while the figure is the 95th percentile of the system's samples — over 100% is worth reading, but is not by itself a violation. Formal violations are listed separately. These are the utilities' own EPA-reported results, not a city-wide average. A detection means the lab measured the substance — it isn't the same as exceeding a legal limit. Hover a source tag to see the EPA program and years behind each figure.

Water suppliers serving Johnstown

Supplier	Population served
JOHNSTOWN CITY PWS	5,200
GREEN MEADOWS MHP	51

Frequently asked questions about Johnstown tap water

Is Johnstown tap water safe to drink?

EPA testing detected 18 contaminants in the water serving Johnstown. A detection isn't the same as a violation — most detected levels are within federal limits. Check the level and source for each contaminant above, and your utility's annual Consumer Confidence Report for the official compliance status.

How many water suppliers serve Johnstown?

2 public water suppliers report drinking-water monitoring for Johnstown, Ohio to the EPA. Each is listed above with its population served.

What contaminants are in Johnstown's water?

The contaminants EPA monitoring detected in Johnstown include Fluoride, Nitrate, Nitrate-Nitrite, Copper, TTHM. The full list, with the level at the main supplier and the data source, is in the table above.

Where does this data come from?

Every figure is official EPA drinking-water monitoring — the Lead & Copper Rule, the UCMR-5 nationwide testing program, and the EPA Six-Year Review — not our own testing. Each number is labelled with its source and period.