The Marine Corps has completed an Environmental Assessment (EA) under the National Environmental Policy Act (NEPA) for the P-875 Water Reclamation Facility (WRF) Upgrades at Marine Corps Base Hawaii (MCBH). The EA involved a detailed analysis of the environmental effects of the facility upgrades, extensive consultations with local community and government agencies, and full consideration of public comments. The EA summarized MCBH’s findings of effects to its environmental resources including noise, air quality, water resources, cultural resources, terrestrial biological resources, utilities, and transportation, and concluded the proposed facility upgrades would have less than significant effects to these resources. This EA also included an analysis of the cumulative effects associated with past, present, and reasonably foreseeable future actions. Based on the results of this analysis, the Marine Corps determined that an Environmental Impact Statement (EIS) is not required and explained this determination in a Finding of No Significant Impact (FONSI) document. The EA, FONSI, all accompanying documents, and additional information can be found at: (https://planning.hawaii.gov/erp ) and on the MCBH website (https://www.mcbhawaii.marines.mil/Offices-and-Staff/Environmental/#tab/environmental-evaluations).

The proposed action is to upgrade the existing WRF and to construct and operate a redundant wastewater treatment system. The WRF is a secondary biological treatment plant designed to accommodate an average daily flow of 2 million gallons per day (mgd). It is the only means of treating wastewater at MCBH Kaneohe Bay.  The purpose of the proposed action is to eliminate noncompliant discharges during planned maintenance events and unscheduled repairs by upgrading the existing infrastructure and constructing a redundant system equal to the capacity of the existing facility. The proposed action is designed to meet water quality and disinfection permit standards but would also provide new water reuse capabilities on base. The proposed action is needed to provide treatment processes that will ensure compliance with MCBH’s National Pollutant Discharge Elimination System wastewater permit and resolve outstanding deficiencies.

This proposed upgrade to the current facility and development of redundant capacity at the WRF has been in development for several years. The existing WRF lacks the capability to ensure that treated effluent continues to meet existing permit limitations during planned maintenance events and unforeseen repairs without significantly altering the flow process. In addition, upgrades are needed to improve treated water capabilities such that the improved water could again be used for irrigation purposes, thereby reducing overall water demand from the City and County of Honolulu Board of Water Supply.

In accordance with Section 106 of the National Historic Preservation Act, the Marine Corps consulted with the Hawai‘i State Historic Preservation Officer (SHPO), Native Hawaiian Organizations, interested parties, and the public regarding the Marine Corps’ finding that no historic properties would be 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.

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 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 in its Biological Opinion issued on March 28, 2025.

For information concerning the EA and resulting FONSI, please contact Capt Ryan LaLonde, MCBH Environmental Compliance and Protection Division, at (ryan.d.lalonde.mil@usmc.mil).