NOTICE OF CLEAN WATER BRANCH RECOMMENDATIONS FOR
WATER POLLUTION CONTROL PERMIT FOR
KAHE GENERATING STATION
NPDES PERMIT NO. HI 0000019

The State of 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 treated wastewater discharges to receiving State waters, subject to special conditions, to:

HAWAIIAN ELECTRIC COMPANY, INC. (Permittee)

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

The Permittee owns and operates the Kahe Generating Station (Facility) located at 92-200 Farrington Highway, Kapolei, Island of Oahu, Hawaii. The Facility consists of an oil-fired steam electric power generating Facility, which uses Pacific Ocean seawater near Kahe Point in a once-through cooling process. The Facility operates six steam turbine generators with a total net rated capacity of 658 megawatts (MW) 24 hours per day, 365 days a year.

Once-through cooling water used for the turbine generators is primarily pumped from the Pacific Ocean near Kahe Point from two intake bay structures, which are subject to Clean Water Act Section 316(b) requirements. Upon passing through the generator’s systems, the once-through condenser cooling water is discharged back into the Pacific Ocean at a maximum design rate of 861 million gallons per day (MGD) through Outfall Serial No. 001, a submerged outfall located 650 feet offshore at a depth of 27 feet. Outfall Serial No. 001 consists of two 10.75-feet diameter ports that are directed upwards at a 20° angle and located at coordinates latitude 21°21’25″N and longitude 158°08’07″W.

The Facility also discharges a maximum of 0.270 MGD of treated low volume wastes (LVW) once per month; a maximum of 0.350 MGD of treated, non-hazardous metal cleaning wastes (MCW) 2-3 times per month; and storm water runoff through Outfall Serial No. 001. LVW includes wastewater from the micro-filtration/reverse osmosis system, demineralizer system, water treatment evaporator blowdown, laboratory and sampling streams, boiler blowdown, condensate, floor drains, and recirculating house service water systems. MCW includes wastewater resulting from cleaning any metal process equipment, consisting mostly of boiler and air preheater wash water, and fireside wash water. Discharges of storm water runoff will be covered under a separate permit.

The receiving waters, the Pacific Ocean, is classified by the DOH as Class A, Marine, Wet Open Coastal Waters under Hawaii Administrative Rules (HAR), Section 11-54-6. 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.

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 cleanwaterbranch@doh.hawaii.gov or by mail at P.O. BOX 3378, Honolulu, Hawaii 96801-3378. 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, Hawaii 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/.

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. However, fulfillment prior to a final determination cannot be guaranteed. Requests submitted as early as possible are more likely to be fulfilled.

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 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
(SA1532243 7/08/26)