Mercury in Drinking Water
Inorganic Chemical · MCL: 2 ppb · 0 systems exceeding limit
Overview
Mercury is regulated under the Safe Drinking Water Act with an MCL of 2 ppb. The EPA Safe Drinking Water program sets and enforces the maximum contaminant levels shown here.
Health Effects
Exposure to Mercury above the MCL of 2 ppb may cause adverse health effects. Consult EPA fact sheets for detailed information.
Sources of Contamination
Mercury can enter drinking water from natural deposits, industrial discharges, or other sources.
Treatment & Removal
Treatment methods for Mercury include activated carbon filtration, reverse osmosis, and specialized media.
How to Remove Mercury From Water
These filtration methods are effective for reducing Mercury in drinking water:
| Filter Method | Effectiveness | Cost Range | Certification |
|---|---|---|---|
| Activated Carbon Block | 90-95% removal | $30-100 (pitcher/under-sink) | NSF/ANSI 53 |
| Reverse Osmosis (RO) | 95-99% removal | $200-500 (under-sink) | NSF/ANSI 58 |
| Distillation | 99%+ removal | $100-400 (countertop) | NSF/ANSI 62 |
Activated Carbon Block, details
Carbon is highly effective for mercury removal. Most NSF 53-certified filters cover mercury.
Reverse Osmosis (RO), details
Very effective for all forms of mercury.
Distillation, details
Highly effective but slow.
Water Systems with Mercury Detected
Aqua Pa Main System
Bryn Mawr, Pennsylvania
Tucson City Of
Tucson, Arizona
Aquarion-Eastern Fairfield County
Shelton, Connecticut
Glen Burnie-Broadneck
Millersville, Maryland
Gilbert, Town Of
Gilbert, Arizona
Provo City
Provo, Utah
Frequently Asked Questions
Mercury has been detected in 0 water systems that exceed the EPA maximum contaminant level (MCL) of 2 ppb, affecting approximately 0 people. Check your local water system's annual Consumer Confidence Report or search by ZIP code on this site.
Exposure to Mercury above the MCL of 2 ppb may cause adverse health effects. Consult EPA fact sheets for detailed information.
Effective filtration methods for Mercury include Activated Carbon Block, Reverse Osmosis (RO), Distillation. Look for filters certified to NSF/ANSI standards for Mercury removal. See the detailed comparison table above for effectiveness ratings and cost ranges.
The EPA Maximum Contaminant Level (MCL) for Mercury is 2 ppb. The MCL Goal (MCLG), the level with no known health risk, is 2 ppb. Water systems must test regularly and notify customers if levels exceed the MCL.