Kailua Regional Wastewater Treatment Plant
& the Mokapu Outfall
The wastewater treatment plant processes sewage from the windward Ko'olaupoko district except Waimanalo. It is a secondary treatment plant with an average design capacity of 15 million gallons per day. Treated effluent from the Kailua Wastewater Treatment Plant is discharged through the Mokapu Outfall outside the north end of Kailua Bay. The pipe extends a mile offshore into waters 100 feet deep. The discharge transport is primarily northerly or away from the bay shore and largely influenced by winds.