|Ask The Expert: Removing TCE
Q: I found your site through a link from "Well Manager," on which I had been researching a solution for my family's home. It happens that this past week a water test revealed the well water contained 44.0 micrograms per liter (µg/L) of trichloroethylene which is 8.8 times the standard acceptable level. Is there any process or filter to address this situation? Also, we do not yet know the cause or source of the chemical in our well. We had received a letter from our town urging the homeowners in the neighborhood to test because someone else had found a much smaller percentage in their water when digging to put in a new well. If there is any advice you can offer in this predicament, please let us know.
A: Well water with 44 parts per billion (ppb)—1 µg/L = 1 ppb—of trichloroethylene (TCE) does require treatment since the Safe Drinking Water Act has designated TCE levels above 5 ppb as a health concern. The USEPA is currently reevaluating the health effects from TCE and an update is anticipated in 2005. TCE is a colorless, organic liquid used primarily to remove grease from metal parts and some textiles. It is also used in paint strippers, printing correction fluids, adhesives, spot removers, etc.
There are two concerns with this water. First is the long term effect from drinking it and second is inhalation during showering, clothes or dish washing, etc., where volatile TCE becomes airborne and then subject to inhalation. Drinking or ingestion has a moderate toxicity over an extended period of time and may induce liver problems or increase risk of cancer. Inhalation is regarded as having low toxicity resulting in potential for some neurological effects.
For drinking water, any point-of-use (POU) carbon filter that conforms to ANSI/NSF 53 and has a product data sheet claiming TCE removal should be adequate. Standard 53 requires a product reduce TCE levels from 300 to 5 ppb or less. It’s important to follow the installation and maintenance instructions, particularly the carbon element replacement schedule. Product certified for TCE treatment can be found on the Internet at www.nsf.org/certified/dwtu/, www.wqa.org/sitelogic.cfm?ID=1165 or www.ul.com/water/—if you have trouble loading the page, go to the root website and search under the product certification sections. Check with your local water treatment professional, also, because he may have already solved this problem in a neighboring well.
For both inhalation and drinking concerns, a point-of-entry carbon tank filter or an aeration system may be used. Both need to be properly sized for the application flow rates expected. Aeration equipment is relatively complex but the simpler carbon tank filter requires scheduled replacement of the carbon. A local water treatment professional can help with the sizing and installation of either of these means of treatment. Scheduled testing of the water is recommended to confirm effective treatment of the water.
At these levels, the source of this contamination is almost certainly from nearby industrial activity, and I would be after the authorities to locate the culprit, who should be forced to pay for remediation.
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