Treating Drinking Water with 99% Removal

In October 2011, the Cedarburg, Wisconsin Light and Water Utility installed a QED E-Z Tray® (U.S. Patent Number 5,518,668) Air Stripper in a discreet addition to their existing production pump building. The E-Z Tray 72.6 handles a flow rate of 600 gpm and treats groundwater containing vinyl chloride that has been traced back to a nearby landfill. The influent into the Air Stripper is drinking water with 0.22 microgram per litre of vinyl chloride, and the goal is set at complete removal.

Cedarburg has been using a packed tower air stripper for 18 years to treat TCE at a different supply well location, but when vinyl chloride contamination needed to be addressed, Cedarburg Water Utility Supervisor Tim Martin started looking into alternative treatment options, because of numerous design issues with the packed tower.  “Right off the bat I was looking for an alternative.” Martin says.

Because the EPA requires 99% removal of all VOCs, the utility needed an efficient and reliable system. Martin learned about QED’s E-Z Tray, and after running the Online Performance Modeler he realized that the utility could over-design their system to not only treat the current level of vinyl chloride at the 99% removal rate, but be ready to treat any increases in vinyl chloride or other contaminants that may occur in the future. “We are only utilizing 4 of the 6 trays in our system right now. Hopefully, there won’t be any major changes in the groundwater, but we are ready for the future.” Martin says.

Because the treatment facility sits adjacent to a residential neighbourhood the utility also wanted to avoid the conspicuous nature of a packed tower. “The packed tower system necessary to treat the vinyl chloride was going to have to be constructed outside and it would have been about 40 feet tall. Competitive price was a factor in choosing an E-Z Tray, but I liked the fact that the whole process could be constructed indoors.” Martin said. They added E-Z Tray options of hinged doors and split trays to further compact the overall footprint and make it easier for one person to access the unit.

The Cedarburg E-Z Tray system requires no pre-treatment steps or off-gas treatment, making the system fairly low maintenance. Martin expects the trays will eventually need to be cleaned, but the ease of this process and minimum down time required for cleaning were both instrumental in choosing an E-Z Tray for the Cedarburg project. “After one month the trays still look good.” Martin says. “I am very happy with the operation of the system so far.”

For more information on the QED E-Z Tray Air Stripper, visit www.qedenv.com/airstripper where you can learn more about how the E-Z Tray is a time-saving and effective air stripping technology, and you can use the exclusive Online Performance Modeler to pick the right E-Z Tray system for your specific drinking water treatment application.