Chlordane in Drinking Water

🩨 Health Effects

Long-term exposure may cause liver problems, nervous system damage, and increased cancer risk. Chlordane is a persistent organic pollutant that accumulates in the food chain and in fatty tissue.

📍 Sources in Water

Widely used as a termiticide in homes until it was banned in 1988. Can leach from soil into groundwater near treated structures and persist for decades.

✅ What To Do

Activated carbon filtration and reverse osmosis can reduce chlordane. Violations in public water supplies are very rare; it is more of a concern for private wells near homes treated before 1988.

📜 Regulation History

The EPA set the chlordane MCL at 0.002 mg/L (2 ppb) in 1991 under the Phase II rule, with an MCLG of zero. Chlordane was banned for all uses in the US in 1988. As a persistent organic pollutant under the Stockholm Convention, it is banned internationally. The WHO guideline is 0.0002 mg/L, much stricter than the US standard.

🔬 How To Test Your Water

Certified lab tests for chlordane cost $75-$150 using EPA Method 508.1 (GC/ECD). Home test kits are not available. Testing is most relevant for private wells near homes that were treated for termites before 1988.

💧 Which Filters Remove Chlordane?

Granular activated carbon (GAC) is highly effective at adsorbing chlordane from water. Reverse osmosis also removes chlordane. Because chlordane tends to adsorb to soil particles, sediment filtration provides some removal as well. Look for NSF/ANSI 53 certification.

🔗 Related Contaminants