Is Fairfield, Ohio tap water safe?
5 water systems report serving Fairfield. Your water depends on which one serves your address. Check your bill if unsure. This list is matched from the ZIP codes in this place, so it may include nearby systems.
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Greater Cincinnati Water Works
Serves 800,000 people · Surface water · Full report →
No health-based violations in the last 5 years; PFOA/PFOS average above the 4 ppt federal limit: PFOS; Lead 90th percentile below the action level (2026).
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Butler Co. Water District 2 PWS
Serves 116,572 people · Surface water · Full report →
No health-based violations in the last 5 years; 3 monitoring/reporting violations; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
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Hamilton Public Water System
Serves 62,447 people · Groundwater · Full report →
No health-based violations in the last 5 years; 2 monitoring/reporting violations; 1 not yet resolved; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2024).
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Fairfield City PWS
Serves 44,907 people · Groundwater · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2026).
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Southwest Regional Water District
Serves 42,856 people · Groundwater · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).