2024 Water Quality Data — Delaware County, Ohio
What's Really in Delaware County, Ohio Tap Water?
Delaware County draws from the Olentangy River and Delaware Reservoir. Here's what the 2024 water quality data actually shows — and what it means for your Powell, Dublin, or Westerville home.
Get a Free Home Water TestKey Contaminants Found in Delaware County Water
Data sourced from the City of Delaware Water Department / Columbus Water Works (southern areas) 2024 Annual Water Quality Report and EPA monitoring records.
| Contaminant | Detected Level | EPA Limit | Health Concern | Status |
|---|---|---|---|---|
| Water Hardness | 140–200 mg/L | No federal limit | Among the highest in Central Ohio; severe scale buildup, dry skin, appliance damage | Concern |
| Nitrate | 2.8 ppm | 10 ppm | Agricultural runoff from Delaware County farmland; elevated vs. Columbus metro average | Moderate |
| Total Trihalomethanes (TTHMs) | 32 ppb | 80 ppb | Byproduct of chlorine treatment; linked to cancer risk with long-term exposure | Moderate |
| Haloacetic Acids (HAA5) | 18 ppb | 60 ppb | Chlorine disinfection byproduct; potential carcinogen with prolonged exposure | Moderate |
| Lead | Varies (older homes) | 15 ppb action level | Leaches from aging pipes and fixtures; no safe level for children | Concern |
| Chlorine | Up to 4 ppm | 4 ppm (legal max) | Taste/odor issues, skin and hair dryness, forms TTHMs as byproduct | Moderate |
| PFAS (Forever Chemicals) | Trace amounts (some wells) | 4 ppt (new EPA 2024) | Linked to immune, thyroid, and cancer risks; does not break down in the body | Concern |
Water Hardness
ConcernAmong the highest in Central Ohio; severe scale buildup, dry skin, appliance damage
Nitrate
ModerateAgricultural runoff from Delaware County farmland; elevated vs. Columbus metro average
Total Trihalomethanes (TTHMs)
ModerateByproduct of chlorine treatment; linked to cancer risk with long-term exposure
Haloacetic Acids (HAA5)
ModerateChlorine disinfection byproduct; potential carcinogen with prolonged exposure
Lead
ConcernLeaches from aging pipes and fixtures; no safe level for children
Chlorine
ModerateTaste/odor issues, skin and hair dryness, forms TTHMs as byproduct
PFAS (Forever Chemicals)
ConcernLinked to immune, thyroid, and cancer risks; does not break down in the body
What Hard Water Does to Your Delaware County Home
At 140–200 mg/L, Delaware County water is classified as very hard — more than double the national average.
Severe scale buildup — Delaware County water is among the hardest in Central Ohio
Dry, itchy skin and brittle hair after showering
Faded, stiff laundry — detergent doesn't lather well
Spots and film on dishes, glasses, and silverware
Shortened lifespan of dishwashers, washing machines, and water heaters
Higher energy bills — scale-coated water heaters use up to 29% more energy
$850/year
Hard water costs Delaware County homeowners an estimated $850/year in extra energy and appliance repair costs.
Where Does Delaware County Water Come From?
Primary provider: City of Delaware Water Department / Columbus Water Works (southern areas)
Water source: Delaware Reservoir (Olentangy River), Scioto River (southern areas)
How to Fix Delaware County Water Problems
Pure Aqua Columbus installs Westinghouse-authorized systems designed specifically for Central Ohio water conditions.
Water Softener
Delaware County's 8–12 gpg hardness is among the highest in Central Ohio. A whole-house softener eliminates scale, protects appliances, and leaves skin and hair noticeably softer.
Removes:
Whole House Filter
Removes chlorine, TTHMs, nitrates, sediment, and odors at the point of entry — protecting every tap, shower, and appliance in your Delaware County home.
Removes:
Alkaline RO System
Reverse osmosis removes PFAS, lead, nitrates, and hardness minerals at the tap — delivering the purest drinking water possible for your Delaware County family.
Removes:
Frequently Asked Questions
Is Delaware County tap water safe to drink?
Delaware County tap water meets all EPA legal limits and is considered safe by regulatory standards. However, it is among the hardest water in Central Ohio (8–12 gpg) and contains elevated nitrates from agricultural runoff. Many residents choose additional filtration for improved taste, odor, and long-term peace of mind.
How hard is Delaware County Ohio water?
Delaware County water averages 140–200 mg/L (8–12 grains per gallon) — classified as "very hard" and among the highest in the Columbus metro area. This causes significant scale buildup on pipes, appliances, and fixtures, as well as dry skin and hair.
Why does Delaware County water have higher nitrates?
Delaware County has more agricultural land than the Columbus urban core. Fertilizer and livestock runoff can elevate nitrate levels in the Olentangy River watershed. While current levels are well below the 10 ppm EPA limit, families with infants or pregnant women should be aware.
Who provides water to Delaware County?
The City of Delaware Water Department serves the city of Delaware and surrounding areas, drawing from Delaware Reservoir on the Olentangy River. Southern Delaware County communities like Powell and Dublin are largely served by Columbus Water Works.
More Delaware County Water Resources
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