What is 1,2-Dichloroethane* and Why Does It Matter?

1,2-Dichloroethane (also called ethylene dichloride) is a synthetic chemical that rarely occurs in nature. Industrial facilities produce it in large quantities to make PVC plastics, solvents, and other chemicals. It enters drinking water primarily through industrial discharge, improper waste disposal, and underground storage tank leaks. Once in the soil, it moves easily into groundwater — the source of drinking water for millions of Americans.

Right now, 19 water systems across the U.S. have detected 1,2-dichloroethane in their supply. The average level found is 0.219 parts per billion (ppb), with the highest recorded sample reaching 0.34 ppb. While those numbers sound small, they're worth understanding — especially for families with young children or pregnant women at home.

Health effects depend on both the amount and the duration of exposure. Short-term contact with high concentrations can cause nausea, dizziness, and liver stress. Long-term, low-level exposure is the bigger concern. The U.S. Environmental Protection Agency (EPA) classifies 1,2-dichloroethane as a probable human carcinogen, meaning it has shown the ability to cause cancer in animal studies and may pose similar risks to people. The International Agency for Research on Cancer (IARC) shares that classification. Research links chronic exposure to increased risk of liver and kidney damage, and potentially certain cancers with prolonged intake.

The EPA's legal limit — called the Maximum Contaminant Level (MCL) — for 1,2-dichloroethane in drinking water is 5 ppb. None of the 19 systems currently exceed that threshold. However, the Environmental Working Group (EWG) sets a much stricter health guideline of 0.02 ppb, based on a one-in-a-million cancer risk standard. At an average of 0.219 ppb, detected systems are running more than 10 times above that EWG benchmark. This gap between legal compliance and health-based guidance is important. A water system can meet every legal requirement and still contain levels that independent health researchers consider a long-term risk.

Geographically, North Carolina leads with 8 affected systems, followed by New York with 5 and Arkansas with 4. Louisiana and Alabama each report 1 affected system. North Carolina's presence at the top isn't surprising — the state has a dense concentration of chemical manufacturing and textile industries, both of which have historically used chlorinated solvents. New York's detections likely tie to legacy industrial sites and aging infrastructure in older urban and suburban areas. Arkansas and Louisiana share proximity to petrochemical corridors along the Mississippi River basin, where industrial activity has long influenced groundwater quality. If you live in any of these states, it's worth pulling your local water quality report — also called a Consumer Confidence Report — to see whether your specific utility has detected this chemical.

The good news is that 1,2-dichloroethane is very treatable. Activated carbon filtration removes it effectively, and reverse osmosis (RO) systems take removal even further — typically eliminating 95% or more of chlorinated organic compounds like this one. If your water tests positive for 1,2-dichloroethane, a certified RO system installed at your kitchen tap is one of the most reliable solutions available. Echo Water's reverse osmosis systems are independently tested to NSF/ANSI standards, which means the performance claims are verified — not just marketing. For renters or those who want a simpler setup, a high-quality activated carbon pitcher or under-sink carbon block filter can also reduce exposure meaningfully. Whatever option you choose, look for NSF certification on the label — it's the clearest sign a filter actually does what it claims.

If you're in North Carolina, New York, Arkansas, Louisiana, or Alabama, consider requesting your utility's most recent water quality report and testing your home's tap water independently. Knowledge is the first step. Filtration is the fix.

Regulatory Standards for 1,2-Dichloroethane*

Cities With the Highest 1,2-Dichloroethane* Levels

States Most Affected by 1,2-Dichloroethane*

Frequently Asked Questions

Related Contaminant Guides