Contaminant reference
Contaminants in US Drinking Water
Detailed guides on every major contaminant found in American tap water — EPA limits, health effects, where it's most common, and which filtration technologies remove it.
No safe level. Neurotoxin from aging pipes in pre-1986 plumbing.
Linked to cancer, thyroid disease, immune suppression. New EPA limits in 2024.
The Erin Brockovich chemical. Carcinogen with no federal limit.
Natural carcinogen in Southwest groundwater. EPA MCL: 10 ppb.
Added intentionally to kill bacteria, but creates harmful disinfection byproducts.
Formed when chlorine reacts with organic matter. Linked to bladder cancer.
Common byproduct of water disinfection. Cancer and reproductive risks.
From fertilizer runoff. Causes blue baby syndrome in infants.
Added to 73% of US systems. Dental benefit debated at current levels.
Not a health hazard, but causes scale, appliance damage, and skin issues.
Universal concern. Endocrine disruption research ongoing. No EPA limit.
Natural in Southwest groundwater. Kidney damage and cancer risk.