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Drinking water quality, IN

Indiana contaminants ranked by SDWA exceedance

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

Top 15 contaminants by exceedance count

ContaminantCategorySamplesAbove MCLMunis affected
1,1,2-trichloroethane-5,2920449
1,1-dichloroethylene-5,2920449
1,2,4-trichlorobenzene-5,2920449
1,2-dibromo-3-chloropropane-4,6020449
1,2-dichloroethane-5,2940449
1,2-dichloropropane-5,2920449
2,3,7,8-tcdd-399099
2,4,5-tp-4,6860449
2,4-d-4,8270449
alachlor-6,0170449
antimony, totalinorganic3,7000449
arsenicinorganic6,9840449
asbestos-61036
atrazine-6,0210449
1,1,1-trichloroethane-5,2920449

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 2026-07-21T09:07:09.986643+00:00.