Is Derry, PA Tap Water Safe? Quality & Contaminants

What was found in Derry'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
Copper	236.3999999999999 µg/L 18% of the EPA limit 1300 µg/L Main supplier: DERRY BORO MUNI AUTH · 6,500 people · 2019	1/1	SYR4
Total Haloacetic Acids (HAA5)	46.86499999999998 µg/L 78% of the EPA limit 60 µg/L Main supplier: DERRY BORO MUNI AUTH · 6,500 people · 2019	1/1	SYR4
TTHM	43.09 µg/L 54% of the EPA limit 80 µg/L Main supplier: DERRY BORO MUNI AUTH · 6,500 people · 2019	1/1	SYR4
Barium	40.62499999999999 µg/L 2% of the EPA limit 2000 µg/L Main supplier: DERRY BORO MUNI AUTH · 6,500 people · 2019	1/1	SYR4
Lead	38.38 µg/L 256% of the EPA limit, at the 95th percentile of samples — 15 µg/L Main supplier: DERRY BORO MUNI AUTH · 6,500 people · 2019	1/1	SYR4
Chloroform	37.535 µg/L No EPA limit set Main supplier: DERRY BORO MUNI AUTH · 6,500 people · 2019	1/1	SYR4
Dichloroacetic Acid	29.6 µg/L No EPA limit set Main supplier: DERRY BORO MUNI AUTH · 6,500 people · 2019	1/1	SYR4
Trichloroacetic Acid	14.699999999999994 µg/L No EPA limit set Main supplier: DERRY BORO MUNI AUTH · 6,500 people · 2019	1/1	SYR4
Bromodichloromethane	6.379999999999999 µg/L No EPA limit set Main supplier: DERRY BORO MUNI AUTH · 6,500 people · 2019	1/1	SYR4
Monochloroacetic Acid	4.3919999999999995 µg/L No EPA limit set Main supplier: DERRY BORO MUNI AUTH · 6,500 people · 2019	1/1	SYR4
Selenium	2.45 µg/L 4.9% of the EPA limit 50 µg/L Main supplier: DERRY BORO MUNI AUTH · 6,500 people · 2019	1/1	SYR4
Dibromochloromethane	1.4294999999999995 µg/L No EPA limit set Main supplier: DERRY BORO MUNI AUTH · 6,500 people · 2019	1/1	SYR4
PFBS	0.0150 µg/L No EPA limit set Main supplier: DERRY BORO MUNI AUTH · 6,500 people · 2023	1/1	UCMR-5
Lead	0.0010 mg/L 6.9% of the EPA limit 0.0150 mg/L Main supplier: DERRY BORO MUNI AUTH · 6,500 people · 2025	1/1	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 Derry

Supplier	Population served
DERRY BORO MUNI AUTH	6,500

Frequently asked questions about Derry tap water

Is Derry tap water safe to drink?

EPA testing detected 14 contaminants in the water serving Derry. 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 Derry?

1 public water supplier report drinking-water monitoring for Derry, Pennsylvania to the EPA. Each is listed above with its population served.

What contaminants are in Derry's water?

The contaminants EPA monitoring detected in Derry include Copper, Total Haloacetic Acids (HAA5), TTHM, Barium, Lead. 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.