Kahului-Wailuku-Sprecklesville-Paia Municipal Disposal

  • Where does your drinking water come from?

    Drinking water is transported from the rivers and ground waters of Na Wai Eha, Maui’s Four Great Waters of West Maui, to Kahului and Wailuku, where it enters the resident's home and is used for household activities and is then flushed down the toilet or drain.

  • Where does your waste water go?

    Untreated wastewater is conveyed through sewer mains to the Kahului-Wailuku Wastewater Reclamation Facility, then the water is treated to "secondary" standards.

  • Waste water disinfection & disposal

    A small portion (5%) is chlorine disinfected and is pumped to in-plant irrigation and industrial uses within the facility, the vast majority (95%) remains infected with pathogens and discharges as R-3 into nearshore injection wells.

  • Waste water reaches the pacific ocean

    The infected injected wastewater flows through groundwater toward the Pacific Ocean, where it emerges often through the reef itself, via openings that present as direct pathways from the wastewater treatment plant to the reef, similar to the flow shown with green dye in the video below.

    See wastewater exiting the reef at Kahekili Beach Maui

  • Drinking Water Sources

    Interesting Facts about Drinking Water Sources

    From County of Maui: "If you live in Upcountry Maui, your water is surface water from the streams in East Maui. It's treated and disinfected at one of our three water treatment facilities (Kamole, Piiholo, Olinda) before it's delivered to your home. Customers in Haiku get their water from the Haiku or Kaupakalua wells and/or the Kamole Weir. Hana and Molokai also use groundwater. Lahaina has a mix of surface water and groundwater. The water treatment facilities for West Maui are located above Lahainaluna School and near the Kapalua Airport.

    For Central Maui (Kahului, Wailuku, Waihe'e, Waikapū, Waiehu, Ma'alaea, Kihei, Wailea, Makena, Sprecklesville and Paia) your water is from surface and groundwaters of Na Wai Eha, Maui’s Four Great Waters of West Maui, which includes the ‘Īao Aquifer under the West Maui Mountains. That water is naturally filtered by lava rocks, disinfected, and sent to your home. A small amount of filtered surface water is added to the Central System at the Iao WTF."

    The Iao and Waihee aquifer region has been designated by the Commission on Water Resources Management as a “water management area” due to over pumping. This points out that water reuse can alleviate stress on our primary drinking water source for Central & South Maui.

    Na Wai Eha, The Four Great Waters of West Maui

    Na Wai Eha, The Four Great Waters of West Maui

  • Municipal Disposal Methods

    Kahului municipal wastewater reclamation facility disposal methods

    Resident Disposal Methods


    Chlorine Disinfected Reuse


    Infected Nearshore Injection Wells

    Interested in seeing present Kahului wastewater reclamation facility reuse locations and future plans for SAT basin disposal?

  • Injection Well Plume
    Visualization of the submarine wastewater discharge plume of infected R-3 effluent present in the Pacific Ocean adjacent to the Kahului-Wailuku Wastewater Reclamation Facility, indicated by N15 nitrogen content in marine limu tissue samples. (Amato 2016) 1

Do You Know What Happens After You Flush?