Chromium-6 (hexavalent chromium, Cr(VI)) became nationally known after the Hinkley, California groundwater contamination case documented in the Erin Brockovich story — but it’s a widespread…

Iron is one of the most common and most disruptive water quality problems for private well owners and facilities drawing from groundwater. It stains fixtures

Fluoride in drinking water is a case where the dose determines the effect. At low concentrations (0.7 mg/L — the current US public water fluoridation

Nitrates are one of the most common groundwater contaminants in the United States, particularly in agricultural regions where nitrogen fertilizers and animal waste enter the

Lead doesn’t belong in drinking water at any concentration. The EPA’s current action level is 15 parts per billion (ppb), but the agency’s own Maximum

Arsenic is a naturally occurring element found in rock formations, soil, and groundwater across the United States — particularly in the western states, New England,

Per- and polyfluoroalkyl substances (PFAS) are a group of over 12,000 synthetic chemicals that have been used in manufacturing and consumer products since the 1940s.