Water Reclamation Facility Upgrades Environmental Assessment
The Marine Corps prepared this Environmental Assessment (EA) in accordance with the National Environmental Policy Act (NEPA), the Department of Navy (DON) procedures/regulations for implementing NEPA at 32 Code of Federal Regulations (C.F.R.) part 775, and Marine Corps Order (MCO) 5090. The proposed action is 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. This EA informs interested parties of potential impacts associated with the Marine Corps’ proposed action. Based upon the EA, a Finding of No Significant Impact (FONSI) has been prepared and a determination made that the preparation of an environmental impact statement (EIS) is not required.
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.
AGENCY COORDINATION AND PUBLIC INVOLVEMENT
Pursuant to Section 7(a)(2) of the Endangered Species Act (ESA), the Marine Corps conducted formal and informal consultation with the U.S. Fish and Wildlife Service (USFWS) regarding potential effects to ESA-listed species. The Marine Corps prepared a Final Biological Assessment (Appendix D) to initiate consultation with USFWS, Pacific Islands Office, under Section 7 of the ESA. The USFWS reviewed and concurred with the Marine Corps’ determination that the proposed action would have no effect or may affect, but is not likely to adversely affect, ESA-listed species at MCBH Kaneohe Bay and issued its Biological Opinion on March 28, 2025.
In accordance with Section 106 of the National Historic Preservation Act, the Marine Corps coordinated with the Hawai‘i State Historic Preservation Officer (SHPO), Native Hawaiian Organizations, interested parties, and the public regarding a finding of no historic properties affected by the proposed action. The SHPO concurred with this finding with the provision that the Marine Corps will provide an archaeological monitoring report following completion of archaeological monitoring (Appendix C).
The Marine Corps solicited public and agency input on the Draft EA from April 8 to May 8, 2025. The Marine Corps published a notice of availability for the review of the Draft EA in the Honolulu Star- Advertiser on April 8, 2025. Printed copies were also available for viewing at the Hawaii Documents Center (Hawaii State Public Library) and at the following libraries on O‘ahu: Kailua Public Library and Kāne‘ohe Public Library. Prior to the release of the Draft EA, MCBH coordinated with the local community at monthly neighborhood board meetings and other public meetings about the proposed action and the Draft EA public comment period. Three comments were received and were individually addressed in Appendix B, Public Comments and Responses. Additionally, comments received outside the formal comment period, such as through the Section 106 consultation process, were considered in the development of the Final EA. All comments received were fully considered by the Marine Corps prior to rendering a decision on the proposed action.
ANNOUNCEMENTS
The Draft EA will be available for review from April 8, 2025, to May 8, 2025.
Final EA DOCUMENTS
PDF files will be provided once the FONSI is signed by MCBH CO.
DRAFT EA DOCUMENTS
PDF: WRF Draft EA
More Information
Fact Sheet
Flyer