Clean Water Branch

NOTICE OF CLEAN WATER BRANCH RECOMMENDATIONS FOR

WATER POLLUTION CONTROL PERMIT FOR

KAILUA REGIONAL WASTEWATER TREATMENT PLANT

NPDES PERMIT NO. HI 0021296

DOCKET NO. HI 0021296

PUBLIC COMMENT PERIOD

December 12, 2024 – January 10, 2024

The Hawaii Department of Health (DOH), Clean Water Branch (CWB) tentatively recommends to the Director of Health (Director) to renew a National Pollutant Discharge Elimination System (NPDES) permit to regulate and impose water pollution control requirements on the discharge of secondary treated wastewater, to receiving State waters, subject to special conditions, to:

CITY AND COUNTY OF HONOLULU

DEPARTMENT OF ENVIRONMENTAL SERVICES

A permit for such discharge would expire five (5) years from the effective date of the permit.

The City and County of Honolulu (Permittee) owns and operates the facility, located at 95 Kaneohe Bay Drive in Kailua, Hawaii, on the Island of Oahu. The facility has a dry weather design flow capacity of 15.25 million gallons per day (MGD) and provides secondary treatment of wastewater from domestic and industrial sources for a population of approximately 94,000 in the communities of Ahuimanu, Kaneohe, and Kailua.

Wastewater generated in the Ahuimanu area receives treatment at the Ahuimanu Preliminary Treatment Facility (PTF) prior to being conveyed to the Kaneohe PTF. Wastewater generated in the Kaneohe area is treated at the Kaneohe PTF and is then conveyed to the facility. Wastewater generated in the Kailua area is gravity-fed directly to the facility.  Treatment at the facility consists of mechanical fine bar screens, grit removal systems, primary clarifiers, biotowers, aerated solids contact tanks, and secondary clarifiers.  Sludge processing consists of dissolved air flotation thickeners, anaerobic digestors, and centrifuges for further solids processing. Solids are hauled to H-Power for waste to energy conversion and is only disposed of in a landfill when H‑Power is unavailable. Storm water runoff from the facility is subject to regulation under the Permittee’s Individual NPDES Permit No. HI S000002.

Treated effluent from the facility commingles with treated effluent from the Marine Corps Base Hawaii Kaneohe WWTP and is conveyed to the Pacific Ocean off of the Mokapu Peninsula through Outfall Serial No. 001 (Mokapu Outfall) at Latitude 21°27’17.0” N and Longitude 157°42’44.1” W. The Mokapu Outfall is a deep ocean outfall and consists of a 48‑inch diameter pipeline that extends approximately 3500 feet from shore to a depth of approximately 105 feet below the ocean surface. The diffuser has 80 side ports and two end ports that range in size from 4 inches to 5.5 inches in diameter.

The receiving water, the Pacific Ocean, is classified by the DOH as a Class A, Dry, Open Coastal Water under HAR Section 11-54-6(b).  It is the objective of Class A waters that their use for recreational purposes and aesthetic enjoyment be protected. Any other use shall be permitted as long as it is compatible with the protection and propagation of fish, shellfish, and wildlife, and with recreation in and on these waters.

Copies of the public notice permit recommended by CWB, and other information are available for public inspection, Monday through Friday (excluding holidays) from 7:45 a.m. until 4:15 p.m., at the DOH Clean Water Branch office located at 2827 Waimano Home Road, Room 225, Pearl City, HI 96782. Copies may be bought. Electronic copies of the proposed public notice permit and other information are also available online at https://health.hawaii.gov/cwb/clean-water-branch-home-page/public-notices-and-updates/.

Persons wishing to comment upon or object to the proposed NPDES permit or to request a public hearing, should submit their comments or requests in writing no later than 30 calendar days after the date of this notice, either through E-mail at [email protected] or by mail at P.O. Box 3378, Honolulu, HI 96801‑3378.

For more information or if you have special needs due to a disability and require aid in inspecting and/or commenting on the public notice permit and related information, please contact Mr. Reef Migita, Supervisor of the Engineering Section, Clean Water Branch, at the above address or (808) 586-4309 (Voice) as soon as possible before the end of the comment period. For those who use a TTY/TDD, please call through Sprint Relay Hawaii, at 1 711 or 1-877-447-5991. If a request for assistance is made after the end of the comment period, the CWB will try to fulfill the request, but cannot guarantee that the request can be fulfilled prior to a final determination.

All written comments and requests received on time will be considered. If the Director determines that there is significant public interest, a public hearing may be held after at least 30 calendar days of public notice.

If CWB believes, after considering all timely written comments and all oral comments at any public hearing that may be held, that no substantive changes to the conditions of the public notice permit are necessary or warranted, then CWB may recommend to the Director that the NPDES permit be issued.

Please notify anyone you know who would be interested in this matter.

                                                                                                             DARRYL LUM, P.E.

                                                                                                             Clean Water Branch Chief