Drinking water quality · 2025
What's in Columbus, OH tap water
70 contaminants were measured in the Columbus, OH water system's 2025 annual report. Each is shown below against its federal limit — 2 sit at or above that limit.
- Reporting year
- 2025
- Contaminants measured
- 70
- Over federal limit
- 2
- Approaching the limit
- 0
- Worst contaminant
- Bromate
- Service area
- OH
1.3× the limit
state-level CCR
At or above the federal limit
Where your water comes from · EPA SDWIS
Columbus, OH's drinking water comes from ground water, drawn from 3 sources.
Source
3ground water
- WELL · 3
Treatment
1treatment plant
- COLUMBUS GROVE VILLAGE
Distribution
2storage units
Source: EPA SDWIS facilities inventory. Methodology.
Compliance history
Federal Safe Drinking Water Act violation & enforcement records (EPA SDWIS). A violation is a regulatory determination by the state or EPA — separate from the measured levels above.
- Treatment technique violationHealth-based5 violations on record · most recent Jan 2018resolved
- Other6 violations on record · most recent Nov 20246 open
- Reporting1 violation on record · most recent Jul 20251 open
Source: EPA SDWIS / ECHO. View the full federal record on EPA ECHO ↗
Disinfection byproducts
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| BromateA disinfection byproduct formed when bromide-containing water is treated with ozone. | 0–13 ug/LRangeDublin Road Water Plant | None set | At or above the limit |
+By source (3)— Dublin Road Water Plant, Hap Cremean Water Plant, Columbus Water
| |||
| TTHMTotal trihalomethanes — a group of four chemicals (including chloroform) formed when chlorine reacts with natural organic matter. | 16.5–83.9 ug/LRangeDublin Road Water Plant | None set | At or above the limit |
+By source (4)— Dublin Road Water Plant, Hap Cremean Water Plant, Parsons Avenue Water Plant +1 more
| |||
| HAA5Haloacetic acids — a group of five disinfection byproducts formed when disinfectants react with organic matter. | 4.5–41.1 ug/LRangeHap Cremean Water Plant | None set | Within the limit |
+By source (4)— Hap Cremean Water Plant, Dublin Road Water Plant, Parsons Avenue Water Plant +1 more
| |||
| BromodichloromethaneA trihalomethane disinfection byproduct. | 8.5 ug/LAverageDublin Road Water Plant | None set | Detected — no federal limit |
+By source (4)— Dublin Road Water Plant, Hap Cremean Water Plant, Parsons Avenue Water Plant +1 more
| |||
| BromoformA trihalomethane disinfection byproduct. | 6.4 ug/LAverageParsons Avenue Water Plant | None set | Detected — no federal limit |
+By source (4)— Parsons Avenue Water Plant, Dublin Road Water Plant, Hap Cremean Water Plant +1 more
| |||
| ChloroformA trihalomethane formed when chlorine reacts with organic matter in water. | 16.6 ug/LAverageHap Cremean Water Plant | None set | Detected — no federal limit |
+By source (4)— Hap Cremean Water Plant, Dublin Road Water Plant, Parsons Avenue Water Plant +1 more
| |||
| DibromochloromethaneA trihalomethane disinfection byproduct. | 8.7 ug/LAverageParsons Avenue Water Plant | None set | Detected — no federal limit |
+By source (4)— Dublin Road Water Plant, Parsons Avenue Water Plant, Hap Cremean Water Plant +1 more
| |||
Physical & aggregate
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| TurbidityA measure of cloudiness from suspended particles in the water. | 0.68 NTUReported levelHap Cremean Water Plant | None set | Within the limit |
+By source (3)— Hap Cremean Water Plant, Dublin Road Water Plant, Columbus Water
| |||
| AlkalinityA measure of the water's capacity to neutralize acids. | 48Reported levelColumbus Water | None set | Detected — no federal limit |
| HardnessA measure of dissolved calcium and magnesium minerals. | 115Reported levelColumbus Water | None set | Detected — no federal limit |
| pHA measure of how acidic or basic the water is. | 7.8Reported levelColumbus Water | None set | Detected — no federal limit |
| Specific ConductanceA measure of how well water conducts electricity, which tracks dissolved mineral content. | 512Reported levelColumbus Water | None set | Detected — no federal limit |
| TOCTotal organic carbon — a measure of organic material dissolved in the water. | 2.25–2.87RangeHap Cremean Water Plant | None set | Detected — no federal limit |
+By source (3)— Hap Cremean Water Plant, Dublin Road Water Plant, Columbus Water
| |||
| Total Dissolved SolidsTotal dissolved solids — the combined content of all dissolved minerals and salts. | 313Reported levelColumbus Water | None set | Detected — no federal limit |
Inorganic chemicals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| NitrateA compound from fertilizer runoff, septic systems, and erosion of natural deposits. | 0–6.3 mg/LRangeDublin Road Water Plant | 10 mg/LMCL | Within the limit |
+By source (4)— Dublin Road Water Plant, Hap Cremean Water Plant, Parsons Avenue Water Plant +1 more
| |||
| FluorideA mineral often added to drinking water to help prevent tooth decay. | 0.79–1.03 mg/LRangeParsons Avenue Water Plant | 4 mg/LMCL | Within the limit |
+By source (4)— Parsons Avenue Water Plant, Dublin Road Water Plant, Hap Cremean Water Plant +1 more
| |||
| Ammonia | Not detectedReported levelColumbus Water | None set | None detected |
| Cyanide | Not detectedReported levelColumbus Water | 0.2MCL | None detected |
| BromideA naturally occurring salt found in source water. | 0.055Reported levelColumbus Water | None set | Detected — no federal limit |
| ChlorideA naturally occurring salt compound. | 52Reported levelColumbus Water | None set | Detected — no federal limit |
| SulfateA naturally occurring mineral from rock and soil. | 130.5Reported levelColumbus Water | None set | Detected — no federal limit |
Other
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Chlorine Total | 1.28–1.59 mg/LRangeDublin Road Water Plant | 4 mg/LMCL | Within the limit |
+By source (3)— Dublin Road Water Plant, Hap Cremean Water Plant, Parsons Avenue Water Plant
| |||
| Alachlor | Not detectedReported levelColumbus Water | 0.002MCL | None detected |
| Carbofuran | Not detectedReported levelColumbus Water | 0.04MCL | None detected |
| Carbon Tetrachloride | Not detectedReported levelColumbus Water | 0.005MCL | None detected |
| Chlorobenzene | Not detectedReported levelColumbus Water | 0.1MCL | None detected |
| Chromium | Not detectedReported levelColumbus Water | 0.1MCL | None detected |
| Cis Dichloroethylene 12 | Not detectedReported levelColumbus Water | 0.07MCL | None detected |
| Dichloroethane 12 | Not detectedReported levelColumbus Water | 0.005MCL | None detected |
| Dichloroethylene 11 | Not detectedReported levelColumbus Water | 0.007MCL | None detected |
| Dichloropropane 12 | Not detectedReported levelColumbus Water | 0.005MCL | None detected |
| Oxamyl | Not detectedReported levelColumbus Water | 0.2MCL | None detected |
| Pentachlorophenol | Not detectedReported levelColumbus Water | 0.001MCL | None detected |
| Picloram | Not detectedReported levelColumbus Water | 0.5MCL | None detected |
| Styrene | Not detectedReported levelColumbus Water | 0.1MCL | None detected |
| Trans Dichloroethylene 12 | Not detectedReported levelColumbus Water | 0.1MCL | None detected |
| Trichlorobenzene 124 | Not detectedReported levelColumbus Water | 0.07MCL | None detected |
| Trichloroethane 111 | Not detectedReported levelColumbus Water | 0.2MCL | None detected |
| Twofourd | Not detectedReported levelColumbus Water | 0.07MCL | None detected |
| Vinyl Chloride | Not detectedReported levelColumbus Water | 0.002MCL | None detected |
VOCs & pesticides
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| AtrazineA widely used agricultural herbicide that reaches water through runoff. | 0–0.84 ug/LRangeDublin Road Water Plant | None set | Within the limit |
+By source (4)— Dublin Road Water Plant, Hap Cremean Water Plant, Parsons Avenue Water Plant +1 more
| |||
| Benzene | Not detectedReported levelColumbus Water | 0.005MCL | None detected |
| Dichloromethane | Not detectedReported levelColumbus Water | 0.005MCL | None detected |
| Ethylbenzene | Not detectedReported levelColumbus Water | 0.7MCL | None detected |
| TetrachloroethyleneAn industrial solvent (PCE) used in dry cleaning and degreasing. | Not detectedReported levelColumbus Water | None set | None detected |
| Toluene | Not detectedReported levelColumbus Water | 1MCL | None detected |
| TrichloroethyleneAn industrial solvent (TCE) used in metal degreasing. | Not detectedReported levelColumbus Water | None set | None detected |
| XylenesA group of industrial solvents found in gasoline and paint. | Not detectedReported levelColumbus Water | None set | None detected |
| Simazine | 0–0.06RangeDublin Road Water Plant | None set | Detected — no federal limit |
+By source (4)— Dublin Road Water Plant, Hap Cremean Water Plant, Parsons Avenue Water Plant +1 more
| |||
Metals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Cadmium | 0.001 mg/LReported levelHap Cremean Water Plant | 0.005 mg/LMCL | Within the limit |
+By source (3)— Hap Cremean Water Plant, Dublin Road Water Plant, Columbus Water
| |||
| CopperA metal that enters water from corroding household plumbing. | 0.049 mg/L90th percentileConcentration at | 1.3 mg/LAction level | Within the limit |
| BariumA metal from erosion of natural deposits and industrial discharge. | 0.02 mg/LReported levelHap Cremean Water Plant | 2 mg/LMCL | Within the limit |
+By source (3)— Hap Cremean Water Plant, Dublin Road Water Plant, Columbus Water
| |||
| Antimony | Not detectedReported levelColumbus Water | 0.006MCL | None detected |
| ArsenicA naturally occurring element that also enters water from industry and agriculture. | Not detectedReported levelColumbus Water | 0.01MCL | None detected |
| Beryllium | Not detectedReported levelColumbus Water | 0.004MCL | None detected |
| IronA naturally occurring metal common in groundwater. | Not detectedReported levelColumbus Water | None set | None detected |
| LeadA toxic metal that leaches into water from old service lines, solder, and plumbing fixtures. | 0 mg/L90th percentileAt the tap | 0.015 mg/LAction level | None detected |
| MercuryA toxic metal from erosion of natural deposits and industrial runoff. | Not detectedReported levelColumbus Water | 0.002MCL | None detected |
| NickelA metal from natural deposits and industrial discharge. | Not detectedReported levelColumbus Water | None set | None detected |
| SeleniumA trace element from natural deposits and industrial discharge. | Not detectedReported levelColumbus Water | 0.05MCL | None detected |
| Thallium | Not detectedReported levelColumbus Water | 0.002MCL | None detected |
| AluminumA common element sometimes used as a treatment coagulant. | 0.016Reported levelColumbus Water | None set | Detected — no federal limit |
| CalciumA naturally occurring mineral that contributes to water hardness. | 34Reported levelColumbus Water | None set | Detected — no federal limit |
| MagnesiumA naturally occurring mineral that contributes to water hardness. | 8Reported levelColumbus Water | None set | Detected — no federal limit |
| PotassiumA naturally occurring mineral from rock and soil. | 4.2Reported levelColumbus Water | None set | Detected — no federal limit |
| SodiumA naturally occurring salt component. | 58Reported levelColumbus Water | None set | Detected — no federal limit |
| ZincA naturally occurring metal that can also enter water from corroding pipes. | 0.256Reported levelColumbus Water | None set | Detected — no federal limit |
Microbial
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Cryptosporidium | Not detectedReported levelColumbus Water | None set | None detected |
| Giardia lamblia | Not detectedReported levelColumbus Water | None set | None detected |
| Total ColiformA group of bacteria used as an indicator of overall water-system sanitation. | 0Reported levelColumbus Water | None set | None detected |
Source: Columbus, OH's 2025 Consumer Confidence Report — the annual drinking-water report every U.S. utility is required to publish. The numbers on this page are the utility's own. A water-quality report covers an entire service area, not a single address.
People also ask about Columbus, OH's water
+Is Columbus, OH tap water safe to drink in 2025?
The 2025 Consumer Confidence Report for the Columbus, OH water utility lists 2 contaminants at or above the federal limit: Bromate and TTHM. Whether that means the water is "unsafe" depends on which contaminant, how long the exposure, and individual health factors. The table on this page shows the measured value, the federal threshold, and the regulated statistic used for compliance.
+What contaminants are in Columbus, OH tap water?
70 contaminants were measured in Columbus, OH's 2025 Consumer Confidence Report, spanning other, metals, and vocs & pesticides. 36 have an enforceable federal limit; the rest are detected but unregulated. Every measured value, in the utility's own units, is on this page.
+Which contaminants exceed federal limits in Columbus, OH tap water?
2 contaminants in Columbus, OH's 2025 report sit at or above the federal limit: Bromate (1.3× the limit); TTHM (1.0× the limit). The EPA enforces these limits against the regulated reporting statistic — typically a running annual average or 90th percentile — not a one-off sample spike.
+What is the worst contaminant in Columbus, OH tap water?
The contaminant with the highest measured value relative to its federal limit in the 2025 report is Bromate, at 1.3× the federal threshold. It belongs to the disinfection byproducts family of contaminants.
+Where does the data on this page come from?
Every value is transcribed from Columbus, OH's 2025 Consumer Confidence Report — the annual drinking-water report every U.S. public water utility is required by federal law to publish. The original source document is archived and viewable on this site. A water-quality report covers an entire service area, not a single address.
+How often is Columbus, OH's water quality data updated?
Each U.S. public water utility publishes one Consumer Confidence Report per year, covering the prior calendar year's measurements. This page reflects the 2025 report; a new report will replace it once the utility publishes its next annual update.