Final report available from investigation of injection wells at Lahaina wastewater facility

EPA Press Release:

NEWS BRIEF

Final report available from investigation of injection wells at Lahaina wastewater facility

HONOLULU – The U.S. Environmental Protection Agency released a final report, “Lahaina Groundwater Tracer Study” with results from a University of Hawaii investigation of the fate of effluent injected at Maui County’s Lahaina Wastewater Reclamation Facility near the Kaanapali coast.

Funded by the U. S. EPA, U.S. Army Corps of Engineers, and the Hawaii Department of Health (DOH), the University of Hawaii has been studying the effluent flow from Lahaina’s injection wells to the near-shore ocean water since July 2011.

The results of the study conclusively demonstrate that a hydrogeologic connection exists between two of the Lahaina facility’s injection wells and the nearby coastal waters of West Maui. A tracer dye added to the facility’s injection wells 3 and 4 took approximately three months to first emerge from submarine seeps near the shore along North Kaanapali Beach. The seeps are located roughly one-half mile to the southwest of the facility. The results suggest an average travel time from injection wells 3 and 4 to the seeps in excess of one year. The study also estimated that 64 percent of the treated wastewater injected into wells 3 and 4 discharges within two discrete near-shore zones where the submarine seeps are located. Additional key results detailed in the final report include the temperature, salinity, pH, nutrient concentrations, and discharge rate of the monitored submarine discharges.

EPA is carefully reviewing the final study results and is consulting with the Hawaii DOH on appropriate next steps in light of the research findings.  

To see the Final Report please visit: www.epa.gov/region9/water/groundwater/uic-permits.html#lahaina

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