1,4-Dioxane in Maryland Drinking Water
Ranked by max 1,4-dioxane detected (µg/L) · UCMR 3 data (2013–2015) · Data from EPA SDWIS & UCMR
1,4-Dioxane in Maryland: what the data shows
Maryland has 3 cities with 1,4-dioxane data from the EPA's UCMR 3 program (2013–2015). 1,4-Dioxane was detected above the 0.35 µg/L EPA health advisory in 1 of those cities. The state average max detected level is 0.29 µg/L. 1,4-Dioxane is a synthetic industrial chemical used as a solvent stabilizer. It enters water supplies primarily from industrial discharge and contaminated groundwater plumes near manufacturing sites, landfills, and military bases. It is highly mobile in groundwater and resistant to biodegradation. The EPA classifies 1,4-dioxane as a likely human carcinogen. Long-term exposure is associated with liver and kidney damage. Advanced oxidation processes (AOP) are the most effective treatment; conventional water treatment and standard carbon filters are generally ineffective against 1,4-dioxane.
Cities exceeding 0.35 µg/L EPA HA (no MCL)
1,4-Dioxane data across Maryland
Each dot is a city with UCMR 3 1,4-dioxane testing data. Cities where 1,4-dioxane exceeds the 0.35 µg/L EPA health advisory are highlighted. Size reflects population served.
Top 10 cities by 1,4-dioxane level in Maryland
Highest 1,4-Dioxane levels (µg/L)
All Maryland cities ranked by 1,4-dioxane level
| # | City | Level | Level | Over HA? | Violations | Grade |
|---|---|---|---|---|---|---|
| 1 | Aberdeen | 0.69 µg/L | Over HA | 0 | B | |
| 2 | Havre De Grace | 0.10 µg/L | No | 13 | C | |
| 3 | Salisbury | 0.08 µg/L | No | 26 | F |
Frequently asked questions about 1,4-dioxane in Maryland
Is 1,4-dioxane in Maryland tap water dangerous?
1,4-Dioxane is classified by the EPA as a likely human carcinogen. There is no federal MCL, but the EPA health advisory is 0.35 µg/L. 1 cities in Maryland exceed the health advisory level. Long-term exposure is associated with liver and kidney damage.
How can I remove 1,4-dioxane from my drinking water?
1,4-Dioxane is one of the most difficult contaminants to remove from water. Standard carbon filters and conventional water treatment are generally ineffective. Advanced oxidation processes (AOP) used by water utilities are the most reliable. At the household level, some high-end reverse osmosis systems may provide partial reduction, but no standard point-of-use filter is certified for 1,4-dioxane removal.
Where does 1,4-dioxane come from in Maryland water?
1,4-Dioxane is a synthetic industrial chemical primarily used as a solvent stabilizer in chlorinated solvent degreasing operations. It enters water from industrial discharge, contaminated groundwater plumes near manufacturing sites, landfills, and military bases. It is highly water-soluble, does not bind to soil, and resists natural biodegradation, making it a persistent groundwater contaminant.