Tap Water Quality Report
Tap water quality in DELAWARE, Ohio
Tap water in DELAWARE, Ohio receives a grade of D (63/100) from TapWaterSafety.org. It's served by DEL-CO WATER COMPANY, INC.. The most significant water quality concerns are: PFAS contamination; Haloacetic acids (HAA9) significantly above health guideline; Total trihalomethanes (TTHMs) significantly above health guideline; Haloacetic acids (HAA5) significantly above health guideline. Data sources: EPA SDWIS, EPA ECHO, EWG Tap Water Database.
What's in DELAWARE's tap water
Top water quality concerns identified by the EPA and Environmental Working Group across the utility serving DELAWARE.
PFAS contamination
Severe concernPerfluorooctanoic acid (PFOA) detected. PFAS are persistent chemicals linked to cancer and immune effects with no known safe exposure threshold.
Haloacetic acids (HAA9) significantly above health guideline
Moderate concernHaloacetic acids (HAA9) detected at 46.5 ppb, 774x above the EWG health guideline of 0.06 ppb.
Total trihalomethanes (TTHMs) significantly above health guideline
Moderate concernTotal trihalomethanes (TTHMs) detected at 55.9 ppb, 373x above the EWG health guideline of 0.15 ppb.
Haloacetic acids (HAA5) significantly above health guideline
Moderate concernHaloacetic acids (HAA5) detected at 36.6 ppb, 366x above the EWG health guideline of 0.1 ppb.
EPA compliance record
Official U.S. EPA records for DEL-CO WATER COMPANY, INC. (system ID OH2101412) for the last 3 years. Checked 2026-10-07.
Source: U.S. EPA Enforcement and Compliance History Online (ECHO), from the Safe Drinking Water Information System. See EPA's full report.
Recommended filters for DELAWARE
Filters matched to the specific contaminants in DELAWARE's water supply.
Filter certified for PFOA/PFOS (NSF/ANSI 53 or 58)
$180-$750Reverse osmosis and some carbon block filters reduce PFAS. Look for certification to NSF/ANSI 53 or 58 for PFOA/PFOS.
Carbon filter certified for VOCs (NSF/ANSI 53)
$180-$599Activated carbon is effective for disinfection byproducts. Look for NSF/ANSI 53 VOC reduction.
Disclosure: TapWaterSafety earns a commission from purchases made through these links. This does not influence our scoring methodology or filter selection.
All contaminants detected in DELAWARE's tap water
Every contaminant identified, compared side-by-side against US EPA legal limits, the EU Drinking Water Directive (2020/2184), WHO Guidelines, and California's Public Health Goal. Why we show multiple standards →
| Contaminant | Detected | EWG US health-based |
EPA US legal |
EU DWD Europe |
WHO global |
CA PHG strictest US |
Tested sample year |
Status |
|---|---|---|---|---|---|---|---|---|
| Haloacetic acids (HAA9) Disinfection byproduct |
46.5 ppb | 0.06 | — | — | — | — | — | 774× over |
| Total trihalomethanes (TTHMs) Disinfection byproduct |
55.9 ppb | 0.15 | 80.0 | 100 | — | — | — | 373× over |
| Haloacetic acids (HAA5) Disinfection byproduct |
36.6 ppb | 0.1 | 60.0 | 60 | — | — | — | 366× over |
| Bromodichloromethane Disinfection byproduct |
13.1 ppb | 0.06 | — | — | — | — | — | 218× over |
| Trichloroacetic acid Disinfection byproduct |
17.0 ppb | 0.1 | — | — | — | — | — | 170× over |
| Chloroform Disinfection byproduct |
39.3 ppb | 0.4 | — | — | — | — | — | 98× over |
| Dichloroacetic acid Disinfection byproduct |
15.8 ppb | 0.2 | — | — | — | — | — | 79× over |
| Dibromochloromethane Disinfection byproduct |
3.53 ppb | 0.1 | — | — | — | — | — | 35× over |
| Chromium (hexavalent) Heavy metal |
0.296 ppb | 0.02 | — | — | — | — | — | 15× over |
| Dibromoacetic acid Disinfection byproduct |
0.296 ppb | 0.03 | — | — | — | — | — | 9.9× over |
| Nitrate and nitrite Inorganic |
0.849 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 6.1× over |
| Nitrate Inorganic |
0.845 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 6.0× over |
| Atrazine Pesticide/Herbicide |
0.342 ppb | 0.1 | 3.0 | 0.1 | 100 | 0.15 | — | Fails EU |
| Chlorate Disinfection byproduct |
431.4 ppb | 210.0 | — | — | — | — | — | 2.1× over |
| Perfluorooctanoic acid (PFOA) PFAS |
0.191 ppt | 0.09 | 4.0 | 100 | 100 | 0.007 | — | 2.1× over |
| Molybdenum Other |
10.6 ppb | 40.0 | — | — | — | — | — | Below guideline |
| Simazine Pesticide/Herbicide |
0.00854 ppb | 0.1 | 4.0 | — | — | — | — | Below guideline |
| Monochloroacetic acid Disinfection byproduct |
3.42 ppb | 53.0 | — | — | — | — | — | Below guideline |
| Bromoform Disinfection byproduct |
0.0156 ppb | 0.5 | — | — | — | — | — | Below guideline |
| Barium Heavy metal |
9.22 ppb | 700.0 | 2000.0 | — | 1300 | 2000 | — | Below guideline |
| Perfluorobutanoic Acid (PFBA) PFAS |
3.68 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Manganese Heavy metal |
0.309 ppb | 100.0 | — | 50 | 80 | — | — | Below guideline |
| Monobromoacetic acid Disinfection byproduct |
0.074 ppb | 25.0 | — | — | — | — | — | Below guideline |
| Perfluorohexanoic Acid (PFHxA) PFAS |
2.85 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Vanadium Other |
0.0569 ppb | 21.0 | — | — | — | — | — | Below guideline |
| Perfluoropentanoic Acid (PFPeA) PFAS |
2.29 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Strontium Radiological |
0.566 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Perfluorobutane sulfonate (PFBS) PFAS |
0.668 ppt | 2000.0 | — | — | — | — | — | Below guideline |
| Fluoride Inorganic |
0.961 ppm | — | 4.0 | 1.5 | 1.5 | — | — | Below guideline |
| Lithium Other |
2.52 ppb | — | — | — | — | — | — | Below guideline |
| Nitrite Inorganic |
0.00571 ppm | — | 1.0 | — | — | — | — | Below guideline |
All values in the unit of the detected level. Red cells indicate the detected level exceeds that standard. Some contaminants have limits in some jurisdictions but not others (shown as —). The "Tested" column shows the year each contaminant sample was collected.
Sources: US EPA, EU Drinking Water Directive 2020/2184, WHO Guidelines, California OEHHA PHGs, EWG Tap Water Database.
Treatment plant contact info
For service issues, water quality concerns, or to request a Consumer Confidence Report from DEL-CO WATER COMPANY, INC..