Total Trihalomethanes in Drinking Water
Disinfection Byproduct · MCL: 80 ppb · 9 systems exceeding limit
Overview
Total Trihalomethanes is regulated under the Safe Drinking Water Act with an MCL of 80 ppb. The EPA Safe Drinking Water program sets and enforces the maximum contaminant levels shown here.
Health Effects
Exposure to Total Trihalomethanes above the MCL of 80 ppb may cause adverse health effects. Consult EPA fact sheets for detailed information.
Sources of Contamination
Total Trihalomethanes can enter drinking water from natural deposits, industrial discharges, or other sources.
Treatment & Removal
Treatment methods for Total Trihalomethanes include activated carbon filtration, reverse osmosis, and specialized media.
How to Remove Total Trihalomethanes From Water
These filtration methods are effective for reducing Total Trihalomethanes in drinking water:
| Filter Method | Effectiveness | Cost Range | Certification |
|---|---|---|---|
| Activated Carbon (granular or block) | 90-99% removal | $30-100 (pitcher/faucet/under-sink) | NSF/ANSI 53 |
| Reverse Osmosis (RO) | 80-90% removal | $200-500 (under-sink) | NSF/ANSI 58 |
| Aeration | 70-90% removal | $500-1500 (whole-house) | Varies |
Activated Carbon (granular or block) — details
Carbon is the most effective and affordable method for THMs. Even basic pitcher filters work well.
Reverse Osmosis (RO) — details
Effective but carbon pre-filter does most of the THM work.
Aeration — details
THMs are volatile and can be removed by aeration. Also reduces exposure during showers.
Water Systems with Total Trihalomethanes Detected
Cocoa, City Of
Cocoa, Florida
Gru - Murphree Wtp
Gainesville, Florida
Ecwa Direct
Buffalo, New York
Buffalo Water Authority
Buffalo, New York
Lansing Board of Water & Light
Lansing, Michigan
Wildwood City Water Department
Rio Grande, New Jersey
Alderwood Water District
Lynnwood, Washington
Tucson City Of
Tucson, Arizona
Springfield Water and Sewer Commission
Springfield, Massachusetts
Aurora City Of
Aurora, Colorado
Mobile, Bd. Of W&s Comm. Of the City Of
Mobile, Alabama
Tuscaloosa Water & Sewer
Tuscaloosa, Alabama
Lawton
Lawton, Oklahoma
City of Gulfport
Gulfport, Mississippi
City of Southaven
Southaven, Mississippi
City of Olive Branch
Olive Branch, Mississippi
City of Hattiesburg
Hattiesburg, Mississippi
Wvawc - Huntington Dist
Charleston, West Virginia
Rio Rancho Water & Ww Services
Rio Rancho, New Mexico
Kansas City Board of Public Utilities
Kansas City, Kansas
Olathe, City Of
Olathe, Kansas
Sioux City Water Supply
Sioux City, Iowa
Harford County D.p.w.
Abingdon, Maryland
Minneapolis
Minneapolis, Minnesota
Bloomington
Bloomington, Minnesota
Brooklyn Park
Brooklyn Park, Minnesota
Shreveport Water System
Shreveport, Louisiana
Newark Water Department
Newark, New Jersey
Chandler City Of
Chandler, Arizona
City of Jackson
Jackson, Mississippi
Gilbert, Town Of
Gilbert, Arizona
Clermont Public Water System
Batavia, Ohio
Atlanta
Atlanta, Georgia
Papillion, City Of
Papillion, Nebraska
Kearney, City Of
Kearney, Nebraska