Kulaimao WWTF - Pepeekeo, Hawaii Wastewater Treatment Plant

Kulaimao WWTF is a wastewater treatment facility located in Pepeekeo on the Big Island of Hawaii. It serves a small community of approximately 1,605 residents, providing secondary treatment to protect local water quality. The plant is situated inland, away from the immediate coastal zone, and operates as part of Hawaii's municipal wastewater infrastructure. The plant employs secondary treatment processes, which involve biological treatment to remove organic matter and suspended solids. With a designed capacity of 757.08 m³/day and an average discharge volume of 529.96 m³/day, the facility operates below its capacity, indicating room for future growth. As a US facility, it falls under the Clean Water Act and is subject to National Pollutant Discharge Elimination System (NPDES) permitting, which sets effluent limits to protect receiving waters. The treated effluent from Kulaimao WWTF is discharged into local streams that eventually flow to the Pacific Ocean. The plant plays a crucial role in safeguarding the island's freshwater resources and nearshore marine ecosystems, which support diverse aquatic life and are important for recreation and traditional practices.

Kulaimao WWTF discharges treated wastewater into streams on the windward side of Hawaii Island, which flow into the Pacific Ocean. The receiving waters support diverse aquatic ecosystems, including native fish and invertebrates. The plant's secondary treatment helps reduce nutrient and pollutant loads, protecting downstream coral reefs and coastal habitats that are ecologically sensitive and culturally significant.