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Tap water quality report

Delaware, OH

EPA monitoring detected 32 contaminants across the 2 water suppliers serving Delaware. A detection doesn't automatically mean the water is unsafe — see the level at the main supplier for each below, with its EPA source and period.

2
water suppliers
193,895
people served
32
contaminants found
Ohio rankings Lead in Ohio PFAS in Ohio

What was found in Delaware'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.

ContaminantLevel vs EPA limitSuppliersSource
Nitrate
1704.5 µg/L 17%
of the EPA limit 10000 µg/L
Main supplier: DEL-CO WATER COMPANY, INC. · 150,000 people · 2019
Highest in the city: 4400 µg/L — DELAWARE CITY PWS · 43,895 people · 2019
2/2 SYR4
Nitrate-Nitrite
1702.5 µg/L 17%
of the EPA limit 10000 µg/L
Main supplier: DEL-CO WATER COMPANY, INC. · 150,000 people · 2019
Highest in the city: 4400 µg/L — DELAWARE CITY PWS · 43,895 people · 2019
2/2 SYR4
Fluoride
1095 µg/L 27%
of the EPA limit 4000 µg/L
Main supplier: DEL-CO WATER COMPANY, INC. · 150,000 people · 2019
Highest in the city: 1339 µg/L — DELAWARE CITY PWS · 43,895 people · 2019
2/2 SYR4
Copper
210 µg/L 16%
of the EPA limit 1300 µg/L
Main supplier: DEL-CO WATER COMPANY, INC. · 150,000 people · 2019
2/2 SYR4
Nitrite
180 µg/L 18%
of the EPA limit 1000 µg/L
Highest in the city: DELAWARE CITY PWS · 43,895 people · 2018
1/2 SYR4
TTHM
74.225 µg/L 93%
of the EPA limit 80 µg/L
Main supplier: DEL-CO WATER COMPANY, INC. · 150,000 people · 2019
Highest in the city: 103.36 µg/L — DELAWARE CITY PWS · 43,895 people · 2019
2/2 SYR4
Chloroform
57.75 µg/L
No EPA limit set
Main supplier: DEL-CO WATER COMPANY, INC. · 150,000 people · 2019
Highest in the city: 83.94 µg/L — DELAWARE CITY PWS · 43,895 people · 2019
2/2 SYR4
Barium
21.9 µg/L 1.1%
of the EPA limit 2000 µg/L
Main supplier: DEL-CO WATER COMPANY, INC. · 150,000 people · 2019
Highest in the city: 66 µg/L — DELAWARE CITY PWS · 43,895 people · 2019
2/2 SYR4
Total Haloacetic Acids (HAA5)
49.69 µg/L 83%
of the EPA limit 60 µg/L
Main supplier: DEL-CO WATER COMPANY, INC. · 150,000 people · 2019
2/2 SYR4
Gross Beta Particle Activity
25 pCi/L
No EPA limit set
Highest in the city: DELAWARE CITY PWS · 43,895 people · 2014
1/2 SYR4
Trichloroacetic Acid
24.925 µg/L
No EPA limit set
Main supplier: DEL-CO WATER COMPANY, INC. · 150,000 people · 2019
2/2 SYR4
Dichloroacetic Acid
22.8 µg/L
No EPA limit set
Main supplier: DEL-CO WATER COMPANY, INC. · 150,000 people · 2019
Highest in the city: 24.345 µg/L — DELAWARE CITY PWS · 43,895 people · 2019
2/2 SYR4
Lead
23 µg/L 153%
of the EPA limit, at the 95th percentile of samples — 15 µg/L
Main supplier: DEL-CO WATER COMPANY, INC. · 150,000 people · 2018
2/2 SYR4
Bromodichloromethane
15.37 µg/L
No EPA limit set
Main supplier: DEL-CO WATER COMPANY, INC. · 150,000 people · 2019
Highest in the city: 17.945 µg/L — DELAWARE CITY PWS · 43,895 people · 2019
2/2 SYR4
Lithium
12.9 µg/L
No EPA limit set
Main supplier: DEL-CO WATER COMPANY, INC. · 150,000 people · 2024
Highest in the city: 15.4 µg/L — DELAWARE CITY PWS · 43,895 people · 2024
2/2 UCMR-5
Dibromochloromethane
4.6 µg/L
No EPA limit set
Main supplier: DEL-CO WATER COMPANY, INC. · 150,000 people · 2019
Highest in the city: 5.8 µg/L — DELAWARE CITY PWS · 43,895 people · 2019
2/2 SYR4
Monochloroacetic Acid
4.25 µg/L
No EPA limit set
Main supplier: DEL-CO WATER COMPANY, INC. · 150,000 people · 2019
Highest in the city: 4.66 µg/L — DELAWARE CITY PWS · 43,895 people · 2019
2/2 SYR4
Atrazine
0.6580 µg/L 22%
of the EPA limit 3 µg/L
Main supplier: DEL-CO WATER COMPANY, INC. · 150,000 people · 2019
Highest in the city: 4.1 µg/L — DELAWARE CITY PWS · 43,895 people · 2019
2/2 SYR4
Arsenic
3.095 µg/L 31%
of the EPA limit 10 µg/L
Highest in the city: DELAWARE CITY PWS · 43,895 people · 2019
1/2 SYR4
Dibromoacetic Acid
1.465 µg/L
No EPA limit set
Main supplier: DEL-CO WATER COMPANY, INC. · 150,000 people · 2019
Highest in the city: 2.3 µg/L — DELAWARE CITY PWS · 43,895 people · 2019
2/2 SYR4
Monobromoacetic Acid
1.925 µg/L
No EPA limit set
Main supplier: DEL-CO WATER COMPANY, INC. · 150,000 people · 2019
1/2 SYR4
Xylenes, Total
1.4625 µg/L 0%
of the EPA limit 10000 µg/L
Main supplier: DEL-CO WATER COMPANY, INC. · 150,000 people · 2019
2/2 SYR4
Toluene
0.8885 µg/L 0.1%
of the EPA limit 1000 µg/L
Main supplier: DEL-CO WATER COMPANY, INC. · 150,000 people · 2019
Highest in the city: 1.2 µg/L — DELAWARE CITY PWS · 43,895 people · 2019
2/2 SYR4
Simazine
0.1780 µg/L 4.5%
of the EPA limit 4 µg/L
Main supplier: DEL-CO WATER COMPANY, INC. · 150,000 people · 2019
Highest in the city: 0.8050 µg/L — DELAWARE CITY PWS · 43,895 people · 2019
2/2 SYR4
Bromoform
0.5000 µg/L
No EPA limit set
Main supplier: DEL-CO WATER COMPANY, INC. · 150,000 people · 2019
Highest in the city: 0.6000 µg/L — DELAWARE CITY PWS · 43,895 people · 2019
2/2 SYR4
Lasso
0.6000 µg/L 30%
of the EPA limit 2 µg/L
Main supplier: DEL-CO WATER COMPANY, INC. · 150,000 people · 2019
1/2 SYR4
Pfba
0.0107 µg/L
No EPA limit set
Main supplier: DEL-CO WATER COMPANY, INC. · 150,000 people · 2024
1/2 UCMR-5
Pfhxa
0.0087 µg/L
No EPA limit set
Main supplier: DEL-CO WATER COMPANY, INC. · 150,000 people · 2024
1/2 UCMR-5
Pfpea
0.0063 µg/L
No EPA limit set
Main supplier: DEL-CO WATER COMPANY, INC. · 150,000 people · 2024
1/2 UCMR-5
PFBS
0.0043 µg/L
No EPA limit set
Main supplier: DEL-CO WATER COMPANY, INC. · 150,000 people · 2024
1/2 UCMR-5
PFOA
0.0042 µg/L
No EPA limit set
Main supplier: DEL-CO WATER COMPANY, INC. · 150,000 people · 2024
1/2 UCMR-5
Lead
0.00082 mg/L 5.5%
of the EPA limit 0.0150 mg/L
Main supplier: DEL-CO WATER COMPANY, INC. · 150,000 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 Delaware

SupplierPopulation served
DEL-CO WATER COMPANY, INC. 150,000
DELAWARE CITY PWS 43,895

Frequently asked questions about Delaware tap water

Is Delaware tap water safe to drink?

EPA testing detected 32 contaminants in the water serving Delaware. 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 Delaware?

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

What contaminants are in Delaware's water?

The contaminants EPA monitoring detected in Delaware include Nitrate, Nitrate-Nitrite, Fluoride, Copper, Nitrite. 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.