Oklahoma Tap Water Quality
Check a Oklahoma ZIP Code
Overview
Oklahoma City pipes water from reservoirs across the state (including Canton Lake and southeast Oklahoma's Atoka pipeline) and Tulsa draws Spavinaw and Oologah lakes; both metros meet all federal standards.
Rural Oklahoma shows the strain: many small systems face disinfection byproduct exceedances and aging plants, southeastern karst and old zinc-mining land (the Tar Creek Superfund site at Picher) left localized metals contamination, and naturally occurring arsenic, selenium, and chromium appear in western groundwater pockets.
Common Contaminants in Oklahoma
The most common exceedance across small reservoir-fed systems with long distribution runs
Tar Creek's lead and zinc contaminated Ottawa County groundwater; affected communities were relocated or connected to alternate supplies
Natural pockets in western Oklahoma groundwater trigger occasional small-system violations
Violations & Compliance
The metros are reliably compliant; Oklahoma's violation counts concentrate in its very large roster of small rural systems, and consolidation moves slowly. Tar Creek remains one of the nation's oldest active Superfund sites.
Water Hardness in Oklahoma
Hard, typically 100–250 mg/L. Reservoir-fed systems (Oklahoma City, Tulsa) are moderately hard; western Oklahoma groundwater is very hard.
Hardness affects taste, limescale, and soap — not safety. Compare levels across all cities or read the water hardness guide.
City Water Reports in Oklahoma
Frequently Asked Questions
Sources & References
The safety rating and guidance on this page draw on the following sources. See our full methodology.
- •US EPA Safe Drinking Water Act regulations
- •EWG Tap Water Database
- •The utility's most recent Consumer Confidence Report (CCR)
- •WHO Guidelines for Drinking-water Quality