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Drinking water quality, OH

Ohio contaminants ranked by SDWA exceedance

Which regulated contaminants exceed their maximum contaminant level (MCL) most often across Ohio's community water systems, per EPA's Six-Year Review sample-level dataset (2012-2019). Source data is public; every value is citable.

Sample data. SYR4 ingest is in flight on prod; this page renders deterministic placeholder data until the V1 importer lands the OH cohort.

Top 5 contaminants by exceedance count

ContaminantCategorySamplesAbove MCLMunis affected
total trihalomethanesdisinfection byproduct1,2407123
haloacetic acids (HAA5)disinfection byproduct9803111
leadlead copper2,1003015
arsenicinorganic720144
nitrate (as nitrogen)inorganic1,85079

For citizens

Look up your own water system by name on the muni search, then read the drinking-water quality band on its profile page for per-contaminant readings + MCL ratios.

Find your utility

For chemical suppliers

Contaminants near or above MCL signal treatment-chemical procurement pressure. Lane intelligence pairs this with per-chemical bid timing on the supplier tier.

Supplier tier overview

Source: EPA Six-Year Review 4 sample-level compliance dataset (2023 release, 2012-2019 monitoring window). Next refresh: SYR5, expected 2029. As of 2026-05-23T00:00:00Z.