Water Reclamation Facility Upgrades Environmental Assessment
The Marine Corps is proposing to upgrade the existing wastewater facility and to construct and operate a redundant wastewater treatment system at the existing Water Reclamation Facility at Marine Corps Base (MCB) Hawaii Kaneohe Bay. The proposed action would allow the Water Reclamation Facility to maintain full capacity during maintenance activities and unscheduled repairs of the existing system, adhere to water quality and disinfection standards, introduce new water reuse capabilities on base, and comply with tsunami design requirements. The Marine Corps has prepared the Draft Environmental Assessment (EA) in accordance with the National Environmental Policy Act of 1969 (NEPA) and applicable regulations and guidance. The Draft EA informs interested parties of potential impacts associated with the Marine Corps’ proposed action.
Overview of Current and Proposed System
PURPOSE AND NEED
The purpose of the proposed action is to eliminate non-compliant discharges during planned maintenance events and unscheduled repairs by upgrading the existing infrastructure and constructing a redundant system of similar capacity as the existing Water Reclamation Facility. The upgraded facility would also provide new water reuse capabilities on base and be constructed to meet tsunami design requirements for greater resilience.
More specifically, the proposed action would allow the Marine Corps to:
• Continually process and treat effluent during maintenance and repairs of the existing Water Reclamation Facility. The new redundant wastewater treatment system would be integrated with and adjacent to the existing Water Reclamation Facility, thereby ensuring treated effluent continues to meet permit requirements during planned maintenance events and unforeseen repairs, with no interruption to the system.
• Upgrade water reuse capability. The proposed upgrade would improve the overall quality of the treated effluent to R-1 standards, which means treated water could be used on base for irrigation, thereby reducing the base’s overall water demand and diverting up to 1 million gallons per day from the ocean outfall.
• Provide disinfection for all of the treated effluent.
• Implement tsunami design standards. New facilities would meet tsunami design requirements consistent with American Society of Civil Engineers specifications.
ABOUT THE WATER RECLAMATION FACILITY AND TREATMENT SYSTEM
The Water Reclamation Facility is a secondary biological treatment plant at MCB Hawaii designed to accommodate an average daily flow of 2 million gallons per day. All sewage generated at MCB Hawaii is treated at the Water Reclamation Facility to meet permitted effluent standards before it is discharged to a shared ocean outfall in Kailua Bay. This shared outfall is also used by the City and County of Honolulu’s Kailua Regional Wastewater Treatment Plant.
PROPOSED ACTION AND NO ACTION ALTERNATIVE
Proposed Action
The Marine Corps evaluated the existing capabilities of the Water Reclamation Facility and the need for design improvements to ensure continued compliance with its National Pollutant Discharge Elimination System (NPDES) discharge permit. The proposed action would improve the existing Water Reclamation Facility and provide a redundant system that allows full plant treatment capability while maintenance and repair activities are conducted. The redundant wastewater treatment system would be constructed over a 3-year period from Fiscal Year (FY) 2025 through FY 2028. The construction would be done in phases to mitigate disruptions to and maintain operation of the Water Reclamation Facility. The construction would occur entirely on previously disturbed areas within the existing Water Reclamation Facility footprint and undeveloped landscaped areas. No modifications to the ocean outfall would occur under the proposed action, and there would be no increase in total discharge quantities.
No Action Alternative
As required by NEPA, the Marine Corps evaluated a No Action Alternative. Under the No Action Alternative, a redundant wastewater treatment system would not be built. The existing Water Reclamation Facility would operate without the upgrades necessary to ensure continued treatment of wastewater during maintenance and repairs, and without a new redundant capability to treat on-base wastewater. The existing facility would not be improved to meet tsunami design requirements, nor would its wastewater be treated to R-1 levels, thereby precluding reuse of any wastewater for irrigation on base.
NEPA PROCESS AND PUBLIC INVOLVEMENT
Public involvement is an integral part of the NEPA process. The Marine Corps is soliciting public and agency input regarding the proposed action through publication of this Draft EA. Public comments on the Draft EA will be considered in the development of the Final EA prior to the Marine Corps rendering its decision on the proposed action. A detailed summary of public comments, revisions made to the EA in response to comments, and responses to comments will be provided in Appendix B of the Final EA. The NEPA Process diagram at right illustrates the stages of public involvement in the environmental review process. The Marine Corps seeks public review and comment on the analysis and conclusions within the Draft EA and the associated National Historic Preservation Act Section 106 consultation.
HOW TO SUBMIT COMMENTS
The Draft EA will be available for a 30-day public review and
comment period starting April 8, 2025; all comments must be
in writing and postmarked or emailed on or before May 8,
2025. Your comments will be considered as part of the decision
-making process.
The Draft EA and Section 106 consultation correspondence
is located at the following locations for review and comment:
• The State of Hawai‘i’s Environmental Review Program website
• A printed copy of the Draft EA is available at the Hawaii Documents
Center (Hawaii State Public Library) • A printed copy of the Draft EA
is available at the following libraries on O‘ahu:
○ Kailua Public Library
○ Kāne‘ohe Public Library
Written comments can be addressed to:
• Peer Amble, Stantec GS Inc., 737 Bishop Street, Suite 3050,
Honolulu, HI 96813
Comments may also be submitted via email to:
MCBH.WRF.EA@stantecgs.com
ANNOUNCEMENTS
The Draft EA will be available for review from April 8, 2025, to May 8, 2025.
DRAFT EA DOCUMENTS
PDF: WRF Draft EA
More Information
Fact Sheet
Flyer