Ultraviolet disinfection to treat wastewater

By December, wastewater from the county’s Lahaina Wastewater Reclamation Facility will be further treated with ultraviolet disinfection, according to the county and a federal annual water report released last week.

The ultraviolet disinfection will help remove matter from the wastewater that is injected into wells that eventually make their way to the ocean through underwater seeps. Currently solids, organic matter and residual suspended matter are removed from the treated wastewater. It is also disinfected with chorine, according to county officials.

The Natural Resources Defense Council said in its report Wednesday that in 2011 the federal Environmental Protection Agency required Maui County to increase wastewater disinfection prior to injection.

The report by the NRDC, which examines cleanliness of the nation’s beach water, said there is a connection between the county’s Lahaina Wastewater Reclamation Facility and its injection wells wastewater that is finding its way to the ocean.

Studies involving the effluent flow from the injection wells to nearshore waters show that the state Department of Health has detected bacterial indicators but at very low levels. A final draft study on the matter has been completed and a final report is due soon.

The state Department of Health will do some seep sampling that will continue through December and a report will be completed in February.

Opponents of the injection wells have said that wastewater flows off shore at nearby Kahekili Beach.

The NRDC report detailing water quality at various beaches, including those on Maui, did not have a listing for Kahekili Beach.