Is Fairfield, OH tap water safe?

Data: U.S. EPA · How we read the data · How we check it

No federal limits exceeded in EPA data for Butler County Water District 2 Public Water System. 2 PFAS were detected below the limits.

4 public water systems serve parts of Fairfield. The largest, Butler County Water District 2 Public Water System, serves 116,572 people. Your water bill names your system.

Largest system

Butler County Water District 2 Public Water System

116,572 people · Purchased surface water · EPA ID OH0900303

Buys treated water from Hamilton Public Water System, Warren County Water System, Cincinnati Public Water System.

PFAS	Highest average	Limit	Status
PFOA Not detected	–	4 ppt	Not detected
PFOS Not detected	–	4 ppt	Not detected
PFHxS Detected, below limit	2.35 ppt	10 ppt	Detected, below limit
PFNA Not detected	–	10 ppt	Not detected
HFPO-DA (GenX) Not detected	–	10 ppt	Not detected

ppt = parts per trillion. "Highest average" is the highest average at any of the system's entry points, the way EPA compares results with the limits.

Lead: 3 ppb at the 90th percentile (Nov 2026, and 9 in 10 homes sampled were at or below it) Below action level
Health-based violations since 2016: 0

Full Butler County Water District 2 Public Water System results

Across Ohio, 35 of 331 water systems EPA tested had PFAS above a 2024 federal limit, and 3 systems were above the lead action level in results from the last five years. Ohio results.

Fairfield homes and lead pipes

56%

of homes built before 1980 (Ohio 63%, US 50%)

built before 1950 (Ohio 25%)

37%

of households rent (Ohio 33%)

Lead service lines and lead solder were allowed until 1986, so homes from before then are the ones to check. Renting? Ask your landlord what the service line is made of, because it's their pipe to replace. How to check your own line.

Housing: Census American Community Survey 2020–2024 5-year estimates for Fairfield city (tables B25034, B25003). Estimates for small places have a margin of error.

Other water systems serving Fairfield

Hamilton Public Water System
62,447 people · Groundwater · Ohio · reported ZIPs here
PFOA detectedAlso: PFHxS detected
Fairfield City Public Water System
44,907 people · Groundwater · Ohio · reported ZIPs here
HFPO-DA detected
Southwest Regional Water District
42,856 people · Groundwater · Ohio · reported ZIPs here
No PFAS above limits

How nearby cities compare

City	Main water system	PFAS	Lead (90th pct.)
Hamilton 4 mi Butler County Water District 2 Public Water System	Butler County Water District 2 Public Water System	None above limits	3 ppb
Mason 13 mi Butler County Water District 2 Public Water System	Butler County Water District 2 Public Water System	None above limits	3 ppb
Cincinnati 13 mi Cincinnati Public Water System	Cincinnati Public Water System	Above limit	2.05 ppb
Middletown 15 mi Butler County Water District 2 Public Water System	Butler County Water District 2 Public Water System	None above limits	3 ppb
Kettering 33 mi Montgomery County Water Services 1 Public Water System	Montgomery County Water Services 1 Public Water System	Above limit	0 ppb
Dayton 36 mi Dayton Public Water System	Dayton Public Water System	Above limit	470 ppb

Fairfield ZIP codes (1)

45014

Questions

Is Fairfield tap water safe to drink?

Butler County Water District 2 Public Water System has had no health-based violations since 2016. Utility data can't show lead from your own pipes: if your home was built before 1986, test your tap. Your utility's annual Consumer Confidence Report is the official summary.

Who supplies water in Fairfield, OH?

4 public water systems serve parts of Fairfield. The largest is Butler County Water District 2 Public Water System (116,572 people). Your water bill names your system. The EPA ID is also on your utility's Consumer Confidence Report.

Does Fairfield tap water have PFAS?

Butler County Water District 2 Public Water System had 2 PFAS detected at least once in EPA's 2023–2025 testing, all with averages below the federal limits.

Do Fairfield homes have lead pipes?

Census estimates put 56% of Fairfield homes as built before 1980 (Ohio: 63%). Lead service lines and lead solder were allowed until 1986, so older homes are more likely to have them. Butler County Water District 2 Public Water System's service line inventory says what your line is made of. The only way to know for your home is to check the line where it enters the house and test your tap.

Source: U.S. EPA drinking water records and PFAS testing (UCMR 5). How we read the data.